JP3673007B2 - Liquid crystal display - Google Patents

Description

【０２７８】
と表せる。最大モアレピッチが最小となるのは
【０２７９】
【数２】

【０２８０】
のときであり、ｎが大きいほどモアレの変調度が小さくなる。したがって、（数２）を満たすようにＰｒ／Ｐｄを決めればよい。ただし、フレネルレンズ５５２は同心円状の溝が形成されており、液晶表示パネル１３３３の画素はマトリックス状に配置されているから、（数２）における各ピッチＰｒ、Ｐｄの決定の仕方が多少難しい。しかし、よりモアレの発生を軽減できる値は（数２）を考慮し実験等により導きだせるであろう。
【０２８１】
なお、（数２）において、ｎは整数値である。画素ピッチＰｄは液晶表示パネル１３３３の画素サイズ等により決定されるから定数値である。したがって、フレネルレンズ５５２のピッチＰｒをフレネルレンズ５５２の作製時に考慮して最適な値に定める必要がある。ｎは整数値であるからＰｒは量子的な値となる。フレネルレンズ５５２の作製時、精度、加工上の問題から上式に合致させて、Ｐｒの値を定めることは困難である。したがって、Ｐｒの値が多少理想値から離れることになる。実用上は多少離れても問題がない。目安として±２０％以内、好ましくは±１０％以内にすればよい。
【０２８２】
フレネルレンズ５５２はアクリルもしくはポリカーボネート樹脂を加工したものである。一例として光洋（株）から発売されているものを採用することができる。フレネルレンズ５５２は少量の場合は工作機械を用いて作製することもできるが、大量に作製する場合は金型を用いて作製する方が容易であり、かつ低コスト化が図れる。フレネルレンズ５５２は平面をランプ１１側にむけているが、反射率を低下させ、これはフレネルレンズ５５２に入射する光量を大きくするためである。また、正弦条件も満足させるためである。
【０２８３】
図８３はフレネルレンズ５５２を一枚使用して集光手段を構成しているが、複数のフレネルレンズ５５２を用いて集光手段を構成してもよいことは言うまでもない。また、フレネルレンズ５５２と平凸レンズとを組み合わせて構成してもよい。また図６０の構成でもよい。図５９（ａ）はフレネルレンズ５５２ａの光入射面を凹面にした構成である。このように凹面に形成することによりレンズに入射する光の角度が相対的に小さくなり反射光は減少する。
【０２８４】
なお、本発明に関連する参考例のビューファインダの説明において液晶表示パネル１３３３に略平行光を入射させるとしたが、これに限定するものではない。たとえば、図５７の光線５１ｂの場合は液晶表示パネル１３３３に入射する主光線は斜めとなっているが、多少の斜めとなっても実用は支障がない。
【０２８５】
フレネルレンズ５５２の溝が、拡大レンズ１３３６を介してみえるため拡散板１５を液晶表示パネル１３３３とフレネルレンズ５５２間に配置する。しかし、特によくみえる（みえてしまう）のはフレネルレンズ５５２の中央部である（図９２の９２１に示す領域）。フレネルレンズ５５２の外周部はほとんどみえない。そこで、図９２（ｂ）に示すようにフレネルレンズ５５２の中央部に拡散部９２１を形成する。拡散部９２１とは具体的には拡散板１５を小さくきったもの等が該当する。その他、図３４の技術的思想を拡散板１５に適用することも有効である。
【０２８６】
なお、拡散板１５とは光学的なローパスフィルタであり、先に説明した拡散板の他、回折格子、プリズムシート、マイクロレンズアレイ、セルホックレンズアレイ等も含む概念である。さらに拡散板等のローパスフィルタを使用せず、以下に示すＭＴＦの概念を用いる方法も含む。
【０２８７】
拡散板１５は集光手段（フレネルレンズ、集光レンズ５２２）からの出射光の指向性を悪くさせ、液晶表示パネル１３３３の表示輝度を低下させる。そこで、拡散板１５を不要とする構成の一方法としてＭＴＦ（Ｍｏｄｕｒａｔｉｏｎ Ｔｒａｎｓｍｉｓｓｉｏｎ Ｆｕｎｃｔｉｏｎ）を考慮すればよい。その説明を図９４に示す。通常、拡大レンズ１３３６は液晶表示パネル１３３３の光変調層にピントがあうようにされている（光変調層の虚像が良好に見えるようにフォーカス調整がされている。あるいは観察者がフォーカス位置が合うように拡大レンズ１３３６の位置を調整する）。ここでピントがあう位置（距離）がｆとする。拡大レンズ１３３６とフレネルレンズ５５２との距離がｆであれば、フレネルレンズ５５２の溝にピントが合う。逆にいえば拡大レンズ１３３６とフレネルレンズ５５２までの距離がｆと異なるほどフレネルレンズ５５２の溝はピンボケとなり観察者からは見えなくなる。
【０２８８】
光学分野では結像（ピント）に関する比較としてＭＴＦを用いる。たとえば、少し乱暴な表現であるが、ＭＴＦが１００％では無限の解像度でピントがあっていることをいう。ＭＴＦが小さいほどピンボケであることを意味する。 図９４に示すように、ＭＴＦは光学系の構成・設計により種々のものを作成できる。 図９４で距離０とは拡大レンズ１３３６と液晶表示パネル１３３３の変調層までの距離がｆである（ピントがあっている）ことを意味する。そこからずれるほど解像度は劣化する。
【０２８９】
光学設計によればピントがあっている点から少しずれるとＭＴＦが急激に劣化する構成（図９４の点線）、かなりはなれてもＭＴＦが劣化しない構成（図９４の実線）が実現できる。本発明に関連する参考例のビューファインダでは、図９４の点線の構成であることが好ましい。
【０２９０】
つまり、ＭＴＦが２０％以下となる位置にフレネルレンズ５５２をおく。実線の場合ではＭＴＦが２０％以下となる点がＸ２とするとビューファインダの全長が長くなってしまう。好ましくはＭＴＦは１０％以下となる位置にフレネルレンズ５５２を配置する。
【０２９１】
以上のようにフレネルレンズ５５２をＭＴＦが低下する位置に配置すれば、フレネルレンズ５５２の溝のＭＴＦ（解像度）が低下し、溝は見えなくなるから、拡散板１５が必要でなくなる。また、フレネルレンズ５５２の溝が見えなくなるということは、溝位置を通過した光が液晶表示パネルに到達したときに周期性がなくなっているため、モアレも発生しにくくなる。
【０２９２】
一例として本発明に関連する参考例のビューファインダに用いたフレネルレンズ５５２の直径は２０ｍｍであり、焦点距離は２２ｍｍである。焦点距離ｄが短くなるほど発光素子（ランプ１１）とフレネルレンズ５５２間の距離ｄを短くできビューファインダのコンパクト化が可能となるが、フレネルレンズ５５２の光集光効率が低下する。逆にあまり焦点距離ｄが長いと光集光効率は良くなるがビューファインダの全長が長くなりすぎる。その場合は、フレネルレンズは２枚用いるべきである。さすれば焦点距離は短くできる。
【０２９３】
フレネルレンズ５５２の焦点距離ｄは液晶表示パネル１３３３の有効表示領域の対角長ｄｐに応じて決定する。焦点距離はｄｐの０．６倍以上２．０倍以下とし、さらに好ましくはｄｐの０．８倍以上１．５倍以下にする。
【０２９４】
ビューファインダは、使用時は使用しやすさの点からも一定の長さ（全長）があった方がよいが、携帯時はできるだけ短いこと（コンパクトなこと）が望ましい。そこで本実施の形態は、液晶表示パネル１３３３とフレネルレンズ５５２間の距離ｄ２および、フレネルレンズ５５２とランプ１１間の距離ｄ１を収縮できるようにしている。そのため、フレネルレンズ５５２はボデー１３２１ｂに取り付けられ、ランプ１１等はボデー１３２１ｃに取り付けられている。図８４は収縮した時の構成図である。図８３のＡ、Ｂ間にバネ等（図示せず）が配置されており、図８３の伸長状態と、図８４の収縮状態とを切り換えることができる。特にフレネルレンズ５５２が平面状であるから収縮しやすい。
【０２９５】
なお、図８３ではｄ１およびｄ２の両方を収縮できるとしたが、図８１に示すように一方のみを収縮できるように構成しても携帯時のコンパクト化に寄与できることはいうまでもない。また凹レンズ１３３６ｂは収差、色補正用のレンズであり、図１の構成のビューファインダにも適用することが好ましい。また、凹レンズ１３３６ｂは凸レンズでもよい。
【０２９６】
ビューファインダは観察者の瞳の位置が接眼カバー１３３２によりほぼ固定されるため、その背後に配置する光源は指向性が狭くてもよい。光源として蛍光管を用いたライトボックス１３３１（図１３７）を用いる従来のビューファインダでは、液晶表示パネル１３３３の表示領域とほぼ同じ大きさの領域からある方向の微小立体角内に進む光だけが利用され、他の方向に進む光は利用されない。つまり、光利用効率が非常に悪い。
【０２９７】
本実施の形態では、発光体の小さな光源１１を用い、その発光体から広い立体角に放射される光をフレネルレンズ５５２等により平行に近い光に変換する。こうすると、フレネルレンズ５５２等からの出射光は指向性が狭くなる。観察者の視点が固定されておれば前述の狭い指向性の光でもビューファインダの用途に十分となる。発光体の大きさが小さければ、当然、消費電力も少ない。以上のように、本実施の形態のビューファインダは観察者が視点を固定して表示画像を見ることを利用している。
【０２９８】
図８５は図８３のビューファインダをビデオカメラ本体４３１に取りつけた構成である。ビューファインダ使用時は留め具８５１（突起）により収縮された状態でビデオカメラ本体４３１に格納される（図８５（ａ）参照）。ビューファインダ使用時は留め具８５１による固定がはずされ（図８３）に示すＡ、Ｂ部が伸長されてランプ１１により液晶表示パネル１３３３に平行光が適正に照射されるようになる。
【０２９９】
しかし、図８３のようにフレネルレンズ５５２とランプ１１間の収縮機構がないとｄ１の距離を短くできずビューファインダの全長が長くなる。その場合は図８１のようにランプ１１とフレネルレンズ５５２間にミラー７５１を配置して光路を折り曲げればよい。図８１の突き出た部分（挿入部８１１）は撮像レンズ４３２を有するビデオカメラ本体４３１に挿入するように設計あるいは構成すれば全く障害とならない（図８１（ｂ）参照）。つまり、挿入部８１１を軸として観察者が見る方向に自由に回転できるようにする（図８１（ｂ）点線を参照）。
【０３００】
ＴＮ液晶表示パネル１３３３は光変調を行うのに偏光板１３３４が必要である。最適な表示コントラストを得るためには偏光子１３３４ａと検光子１３３４ｂとの偏光軸角度を調整する必要がある。その角度は液晶表示パネル１３３３の液晶層に印加する電圧との関係があり、個々の液晶表示パネルの特性にあわせて調整する必要がある場合が多い。図８２に示すようにつまみ８２１はフレネルレンズ５５２につながっており、つまり８２１を上下させることによりフレネルレンズ５５２が回転するとともに偏光子１３３４ａの偏光軸も回転する。したがって偏光軸を個々の液晶表示パネル１３３３の特性にあわせて容易に調整できる。
【０３０１】
図８１の構成は前記調整を容易にした構成である。フレネルレンズ５５２に偏光子１３３４ａを貼り付けている。偏光子１３３４ａはレンズ中心を軸として回転できるように構成されている。つまり、フレネルレンズ５２２を回転させることにより偏光子１３３４ａの偏光軸も回転し、偏光子１３３４ａの偏光軸と検光子１３３４ｂの偏光軸との角度を調整できる。角度を調整することにより表示パネル１３３３の画像が最も良好に見える位置に調整をする。
【０３０２】
ランプ１１から放射された光の一部はフレネルレンズ５５２等で反射されて迷光となる。前記迷光を防止するためにはフレネルレンズ５５２等に反射防止膜を形成すればよい。しかし、反射防止膜を形成しても迷光の発生は完全に防止することはできない。
【０３０３】
迷光は表示画像のコントラストを低下させる要因となる。この問題を回避するために、図９３のようにランプ１１とフレネルレンズ５５２の間に円形絞り９３１を配置してもよい。円形絞り９３１は中央部に円形状窓を有し、複数の絞りが同心円状に所定の間隔を設けて配列されている。円形絞り９３１はランプ１１から出た光がフレネルレンズ５５２の有効領域に直接入射する光だけ通過するようにしている。また、ボデー１３２１と接眼リング１３３５の内面は、光の反射を防止するために黒色あるいは暗色としている。ランプ１１から放射される光のうち、不要な光は円形絞り９３１の遮光部で吸収され、また、吸収されずにわずかに反射する光は他の絞りの遮光部またはボデー１３２１の内面で吸収されるので、フレネルレンズ５５２に入射しない。したがって、液晶表示パネル１３３３への不要光入射による表示画像のコントラスト低下は非常に小さくなる。絞りは１枚でもよいが、枚数が多いほど効果は大きくなる。
【０３０４】
液晶表示パネル１３３３は通常ブラックマトリックス（図示せず）が形成されている。ブラックマトリックスは、液晶表示パネル１３３３の信号線上の液晶の動きを見えなくするため、または／および画素をスイッチングする薄膜トランジスタへの光を遮光するために用いる。しかし、液晶表示パネル１３３３の画素数が少ない場合は前記ブラックマトリックスが目立ち画像品位が低下してしまう。
【０３０５】
そこで、図９３に示すように、液晶表示パネル１３３３と観察者の瞳との間に、光学的ローパスフィルタとして回折格子９３２を配置すれば、ブラックマトリックスを目立ちにくくすることができる。回折格子９３２は拡大レンズ１３３６と液晶表示パネル１３３３間に配置している。また、液晶表示パネル１３３３の入射光側に配置してもよい。但し、配置位置により、回折格子９３２のピッチ、高さ等を変える必要がある事は言うまでもない。回折格子９３２はブラックマトリックスを見えにくくする効果がある。したがって、ブラックマトリックスが見えず滑らかな表示画像が得られる。
【０３０６】
回折格子９３２は透過型のものを用い、格子の断面形状はサインカーブ状、円弧状、台形状などが考えられる。回折格子９３２のパターンは１次元、２次元など多くの変形が考えられる。また、ピッチは、液晶表示パネル１３３３の画素の大きさが１００〜３０μｍで、回折格子９３２を液晶表示パネル１３３３の近くに配置する場合には、１００〜２０μｍの範囲が適当である。
【０３０７】
また、回折格子９３２を拡大レンズ１３３６の近くに配置する場合には、２〜０．１ｍｍが適当である。回折格子９３２の作製方法としては、ＳｉＯ２などの無機物質をガラス基板上に蒸着してパターニングする方法、ガラス基板上にポリマーとドーパントの混合物をスピンコートし、パターンマスクを介して露光した後、減圧加熱によってドーパントを昇華させる方法などがある。回折格子板はクラレ（株）等も製造・販売を行なっている。
【０３０８】
また、拡散板１５は図９９に示すように液晶表示パネル１３３３にはりつけてもよい。収縮機構としては液晶表示パネル１３３３を取付ホルダー９９１に取りつけ、ランプ１１をボデー１３２１に取りつけることにより、図９９、図１００に示すようにビューファインダの全長を収縮、伸縮させることができる。
【０３０９】
フレネルレンズ５５２の問題として、図１０２に示すようにフレネルレンズ５５２内でおこる界面反射がある。特に、入射光８７２がフレネルレンズ５５２の界面１０２２に入射すると図の点線で示すように界面１０２４，１０２３等で反射してしまう。その対策として図１０１に示すようにフレネルレンズ５５２の厚みｔを厚くする方法がある。フレネルレンズ５５２自身を厚くするのは物理的に困難である場合は、透明基板１０１１をフレネルレンズ５５２に透明樹脂９０１ではりつけるとよい。透明基板等の側面（有効表示範囲外、光が直接入射しない領域）に光吸収膜１０１２を塗布する。光吸収膜１０１２として黒色塗料等が例示される。
【０３１０】
以上のようにフレネルレンズ５５２を見かけ上厚くすることにより、図１０３に示すように光線８７２は界面１０３１で一度反射し、側面の黒色塗料１０１２に入射するのでフレネルレンズ５５２内でハレーションが生じない。なお、図１０１において、ｔとｄの関係はｄ／８＜ｔにすればハレーションはほとんど生じず良好な結果が得られた。
【０３１１】
ＰＤ液晶表示パネル１０４１を拡散板１５のかわりに用いれば、拡散度を自由に可変することができる。この構成の説明を図１０４に示す。
【０３１２】
まず、拡散板１５のかわりに用いるＰＤ液晶表示パネル１０４１について説明する。ＰＤ液晶表示パネル１０４１は図２４の動作原理で動作することは先に説明をした。ガラス基板１０４５にはＩＴＯ電極１０４６が形成され、前記ＩＴＯ電極１０４６間にＰＤ液晶層１０４７が狭持されている。なお、１０４４は封止樹脂である。前記ＩＴＯ電極１０４６に電圧が印加されていない時は液晶層１０４７は散乱状態であり、電圧が印加されることによりＰＤ液晶層１０４７は透明状態となる。前記電圧の強弱によってＰＤ液晶層１０４７の拡散の程度は変化する。
【０３１３】
信号発生源１０４２は矩形波を出力し、前記矩形波は信号振幅可変器１０４３で信号振幅を変化させる。信号振幅の可変は抵抗Ｒｂで行う。矩形波の大きさが大きいほどＰＤ液晶層１０４７は透明状態となる。
【０３１４】
ランプ１１から放射された光５１はフレネルレンズ５５２で集光される。その光はＰＤ液晶表示パネル１０４１で光の直進度が変化させられる。したがってＰＤ液晶表示パネル１０４１は拡散板１５と同様にフレネルレンズ５５２の溝をみえにくくする効果を有する。さらに光透過率を変化することから、表示パネル１３３３の表示輝度を調整できるという効果も有する。
【０３１５】
ＰＤ液晶表示パネル１０４１の透過率が高いときは、液晶表示パネル１３３３は高輝度表示を行える。したがって、明るい所で表示画像をみるのに適している。逆にＰＤ液晶表示パネル１０４１の透過率が低いときは液晶表示パネル１３３３の表示画像は暗くなる。しかし、視野角は広くなるので、広範囲から液晶表示パネル１３３３を見る場合に適している。以上のように状況に応じて液晶表示パネル１３３３の表示状態を調整することができる。
【０３１６】
界面による光反射を防止するためには、図１０５に示すように拡散板１５とフレネルレンズ５５２等とを光結合剤ではりつければよい。光透過率が高まり、また界面でのハレーションも低減する。拡散板１５のかわりとしてＰＤ液晶表示パネル１０４１を用いる場合も、図１０６のようにすればよいことは言うまでもない。もちろん図１０６に示すように拡散板１５とＰＤ液晶表示パネル１０４１の両方を用いてもよい。
【０３１７】
なお、以前にも説明したが、図１０７に示すように拡散板１５のかわりに回折格子９３２を用いても拡散板としての機能をはたせることは言うまでもない。また、ランプ１１からの光の放射面積を変化させるために、図１０９のように絞り１０９１をもうける。絞り１０９１とはカメラのシャッタ虹採絞り，しぼり等に用いられるものが例示される。絞り１０９１の穴径を小さくするほど指向性は狭くなり液晶表示パネル１３３３の表示コントラストは向上する。逆に大きくすると指向性は広くなり液晶表示パネル１３３３の表示コントラストは低下するが表示画像は明るくなる。
【０３１８】
本発明に関連する参考例のビューファインダの構成は、拡大レンズ１３３６が有るものとして説明をしてきたがこれに限定されるものではない。たとえば、 図１１０に示すように拡大レンズ１３３６がなくてもよい。この場合観察者が見ることができる表示画像は小さくなるが、液晶表示パネル１３３３サイズが一定以上（１インチ以上が見やすである）の場合は実用上問題がない。
【０３１９】
フレネルレンズ５５２等は透過型として説明してきたが、図１２１に示すように反射型のものを構成できることは言うまでもない。アルミ板等を加工することにより反射型フレネルレンズ１２１１を作製できる。また、ガラス樹脂で成型し、表面にＡｌ等の金属薄膜を蒸着したものでも作製できる。フレネルレンズ１２１１はランプ１１からおよび反射板８８３で反射された光を集光して略平行光にして液晶表示パネル１３３３を照明する。
【０３２０】
ランプ１１からの光は図１１１に示すように導光体１１１１を用いて集光手段（フレネルレンズ、照明レンズ５５２等）に照射させることができる。このように導光体１１１１を用いればランプ１１の配置位置には制約がなくなる。したがってわずかな空間にランプ１１をおけ、スペースの有効利用を行える。
【０３２１】
図１１２に示すように導光体１１１１の外面にＡｌ等の反射膜１１２１が形成され、前記導光体１１１１はランプ１１にかぶせられている。ランプ１１から放射された光は反射膜１１２１間で反射しながら導光体１１１１内を伝達され出射端から放射される。
【０３２２】
図１１２はランプ１１に導光体１１１１をかぶせるとしたが、これに限定するものではなく、図１１３（ａ）に示すようにランプ１１の先端に接着剤１０５１で取り付けてもよい。また、図１１３（ｂ）に示すように複数の光ファイバー１１３１をたばねたものを導光体として用いてもよい。
【０３２３】
図１１４は特に屋外を用いる際に外光（太陽光１１４１等）を用いて液晶表示パネル１３３３を照明する方式である。ビューファインダのボデー１３２１の頂上部には窓があけられ、フレネルレンズ１１４３がはめこまれている。フレネルレンズ１１４３はレンズ厚を薄くするために用いるものであり、許容される際には、プラスチックもしくはガラスレンズの正レンズにおきかえてもよい。太陽光１１４１はほぼ平行光であるから前記光はフレネルレンズ１１４３により集光され、ミラー７５１で反射されて光の進行方向が曲げられ、集光手段５５２に入射する。
【０３２４】
つまり、フレネルレンズ５５２は屋外光１１４１とランプ１１からの光の双方を集光する機能をもつ。
【０３２５】
ミラー７５１で反射される光の状態はランプ１１から放射される光と同様の状態となるような位置に配置される。当然のことながら、屋外光１１４１をボデー１３２１内にとりこまず、液晶表示パネル１３３３を照明する場合は、ランプ１１を発光させて、前記ランプ１１からの光を用いる。
【０３２６】
ランプ１１を発光させるかもしくは屋外光１１４１が弱いときには、補助的にランプ１１を発光させて、表示パネル１３３３に入射する単位面積あたりの光束量（輝度）を一定値にして用いる。ランプ１１を点灯させるか、もしくは点灯した発光輝度の明るさは、ボデー１３２１の頂上部等に配置したホトセンサ１１４２で屋外光１１４１の強弱を判断して決定をする。図１１５はその判断をする回路構成である。ホトセンサ１１４２としてはホトダイオード等が該当する。
【０３２７】
光検出回路１１５２はホトセンサ１１４２とオペアンプＡ₁等からなる積分回路から構成される。オペアンプＡ₁からは屋外光１１４１の強弱に応じて電圧Ｖが出力される。１１５１はヒステリシスコンパレータ回路であり、ヒステリシス状態を決定する抵抗Ｒ₂、Ｒ₃とオペアンプＡ₂およびリファレンス電圧Ｖ₅を発生させる電圧源から構成される。
【０３２８】
オペアンプＡ₁の出力電圧Ｖはリファレンス電圧Ｖ₅と比較される。Ｖが一定値以上のときオペアンプＡ₂の出力端子ａの電圧は＋電圧（もしくは−電圧）となる。前記電圧によりアナログスイッチＳＷ１１５３の接点は閉じ、電圧Ｅ_aがアノード電極２５に印可されてランプ１１は点灯する。逆にオペアンプＡ₂の出力が−電圧（もしくは＋電圧）の点はアナログスイッチＳＷ１１５３はオープンとなる。
【０３２９】
ヒステリシスコンパレータ回路１１５１を用いたのはホトセンサ１１４２に入力する光１１４１には強弱が生じる（たとえば、ビデオカメラを使用中に太陽が雲の影にはいった場合等）のに対処するためである。外光の強弱によりそのつどコンパレータＡ₂の出力が変化するとランプ１１が点滅し、液晶表示パネル１３３３の表示画像が非常にみづらいからである。ヒステリシスコンパレータ回路１１５１を用いることにより、一度ランプ１１が点灯した後は、多少、屋外光１１４１ａが強くなっても消灯しない。したがって、点滅することはなくなる。
【０３３０】
図１１７は図１等に比較して、表示画面の大きい液晶表示パネル１３３３を用いたビューファインダの構成図である。ランプ１１は横置きにして、ビューファインダの全長を短くしている。理解を容易にするため遮光カバー１１７１と液晶表示パネル１３３３等とは離して図示しているが実際上に密着して配置される。遮光カバー１１７１は観察者が見る方向を規定するために用いられる。観察者があまり斜め方向から液晶表示パネル１３３３を見ようとすると、遮光カバー１１７１により液晶表示パネル１３３３の表示画面の周辺部が見えなくなる。
【０３３１】
そのため、観察者は液晶表示パネル１３３３の表示画像を前記画面の正面から見るように心がける。このように接眼カバー１３３３を配置するのはランプ１１から放射される光はフレネルレンズ５５２（又は集光レンズ）により指向性の狭い光に変換され、観察者は前記指向性の狭い光を見ることになるからである。指向性が狭いため液晶表示パネル１３３３の正面以外は急に画像が暗く見える。そのため遮光カバー１１７１を配置して、表示画像が明るく見える方向から見るように観察者を誘導するのである。
【０３３２】
ただし、拡散板１５を配置することにより視野角は拡大されている。拡散板１５の拡散度が高いほど視野角（見る角度により表示画像が見えなくなるまでの角度）が拡大される。しかし、表示画像は暗くなり、表示コントラストも低下してしまう。そのため、拡散板１５の拡散度をできるだけ低くする。そこで、遮光カバー１１７１を用いて、表示画像を良好に見ることができる角度を強制的に規定させるのである。このように構成することにより光源から放射される光を有効に利用し、消費電力を低減できるのである。
【０３３３】
液晶表示パネル１３３３の有効表示領域が大きい場合、あるいはフレネルレンズ５５２の焦点距離が長い場合は全長が長くなる場合があるので、図１１８に示すように、ミラー７５１を用いて光路８７２を屈曲させて構成すればよい。ランプ１１から放射される光はミラー７５１ｂで角度を屈曲されてフレネルレンズ５５２に入射する。
【０３３４】
図１１７では発光素子（ランプ１１）として、小型蛍光放電管１１を用いるものとして図示した。しかし、その発光素子は図８８に示すように小型蛍光管８８２等であってもよい。その小型蛍光管８８２として松下電器産業（株）が製造している品番Ｋ−Ｃ２１Ｔ２６Ｅ８５Ｈ、Ｋ−Ｃ３０Ｔ２６Ｅ８５Ｈ等がある。これらの蛍光管は冷陰極方式でランプ消費電力も０．３３Ｗ、０．４Ｗと少ない。
【０３３５】
前記蛍光管８８２から放射される光を有効に前面に出射できるように、蛍光管８８２の背面にかまぼこ状の反射板８８３を配置する。また、蛍光管８８２からの光を良好に集光するため平板状のシリニドカルレンズ８８１を配置する。発光手段が棒状の発光体であるため同心円状のフレネルレンズ５５２である必要はなくシリニドカルレンズ８８１でもよいからである。
【０３３６】
蛍光管８８２の前面から放射された光は直接シリニドカルレンズ８８１に入射し、集光されて液晶表示パネル１３３３に入射する。蛍光管８８２の後面から放射された光は反射板８３３で反射された後、シリニドカルレンズ８８１に入射して、液晶表示パネル１３３３に入射する。もちろん図１１７のように遮光カバー１１７１を配置してもよい。
【０３３７】
図８３では液晶表示パネル１３３３とフレネルレンズ５５２間の距離ｄ２を使用時に伸張して用いられるように構成している。図８７の構成でも同様のことを実施できる。図８７のように液晶表示パネル１３３３ｂを取り付けたケース８６１とランプ１１を取り付けたケース８７１とをジャバラ８６２ｂで結合し、前記ジャバラ８６２ｂを伸張、収縮させることにより表示パネル１３３３とフレネルレンズ５５２間を調整できるようにすればよい。
【０３３８】
図８７の構成では液晶表示パネル１３３３が大きいため、ランプ１１と集光レンズ５５２間に一定の距離が必要であるため、体積が大きい。これを解決するためには図８６のように構成すればよい。ビューファインダを不使用の場合は、図８６（ａ）のようにジャバラ８６２ａをおりたたんでおく。使用時は 図８６（ｂ）のようにジャバラ８６２ａおよび８６２ｂを引きのばし、集光レンズ５５２の焦点位置にランプ１１の発光部がくるようにする。
【０３３９】
液晶表示パネル１３３３、拡散板１５、集光レンズ５５２はジャバラ８６２を介して一体として固定されている。ジャバラ８６２は外光が進入することも防止および、収縮のため等に用いるものであって、これに限定するものではない。たとえば、図８３に示すように伸縮自在の筒状（１３２１ｂ）のものであってもよい。
【０３４０】
観察者が液晶表示パネル１３３３の表示画像を見やすい方向に調整するのは容易である。回転軸８６３に回転可能なようにビスが固定されており、図８６（ｂ）の点線、実線のように自由に回転、固定できる。特にビデオカメラのモニタとして用いるとき有効である。ビデオカメラで被写体を良好に撮影（撮像）するためにはビューファインダの見る位置を変化させる必要があるからである。
【０３４１】
ランプ１１の頂点もしくは側面から放射される光を有効に利用するためには、図１１９のように構成すればよい。ランプ１１の頂点部から放射される光８７２は図１２０（ｂ）の光８７２ｄのようにミラー８８３ａで反射されて表示パネル１３３３に向かう。もちろん前面から放射される光８７２は直進して表示パネル１３３３に向かう。ランプ１１の側面から放射される光は、図１２０（ａ）に示すようにミラー８８３ｃ、８８３ｂで反射され表示パネル１３３３に入射する。
【０３４２】
図１２０のようにミラー８８３を用いて表示パネル１３３３に斜め方向からの光を入射させることにより観察者が表示パネル１３３３の表示画像を見る時の視角が広がる。つまり、多少眼の位置をずらせても表示画像が急に暗くなることがなくなる。
【０３４３】
図１２３のようにランプ１１ａ、１１ｂというように複数の発光素子を用い、それぞれの発光素子から放射される光を液晶表示パネル１３３３に斜めに（光線１２３２ａ、１２３２ｂ）入射させても視角をひろげることができる。したがって、本発明に関連する参考例のビューファインダにおいて、発光素子（ランプ１１）は１個に限定するものではない。複数の発光素子を用いることにより視角がひろがり、表示画像をみやすくなるという効果が発揮されるからである。
【０３４４】
以上の本発明に関連する参考例のビューファインダは、一枚の液晶表示パネル１３３３で構成されるものであった。しかし、本発明のビューファインダは、これに限定されず、例えば、図９５の構成のものをも含む。
【０３４５】
図９５において、９５２はＰＢＳ（偏光ビームスプリッタ）であり、多数の光学メーカーが発売している（たとえば、日本メレスグリオ様の０３ＰＢＳ０２５等）。ＰＢＳ９５２の光合成面９５１には誘電体薄膜が積層されＰ偏光またはＳ偏光を反射または通過する。
【０３４６】
液晶表示パネル１３３３ａで変調された光はＰＢＳ９５２の光合成面９５１で反射され（Ｐ偏光またはＳ偏光）拡大レンズ１３３６に入射する。一方、液晶表示パネル１３３３ｂで変調された光はＰＢＳ９５２の光合成面９５１を通過し（Ｓ偏光またはＰ偏光）拡大レンズ１３３６に入射する。観察者は２つの液晶表示パネル１３３６の画像を重ね合わせてみるため、画素数が２倍となる。したがって、高精細表示を実現できる。なお、ＰＢＳ９５２のかわりに光の半分を透過させるハーフミラーを用いてもよい。
【０３４７】
ハーフミラーを用いた場合は、ランプ１１ａから放射された光は液晶表示パネル１３３３ａに入射し、前記液晶表示パネル１３３３ａを出射した光がハーフミラー（図９５のＰＢＳ９５２をハーフミラーとおきかえて考えればよい）に入射する。ハーフミラーは前記光の半分を拡大レンズ１３３６側に反射する。一方、ランプ１１ｂから放射された光は、液晶表示パネル１３３３ｂに入射し、前記液晶表示パネル１３３３ｂを出射した光がハーフミラーに入射する。ハーフミラーは同様に前記光の半分を拡大レンズ１３３６側に反射する。液晶表示パネル１３３３ａの光学像と液晶表示パネル１３３３ｂの光学像は半画素だけ位置をずらして２つの光学像を重ね合わせる。
【０３４８】
液晶表示パネルはブラックマトリックスが形成されているため、一方の液晶表示パネル１３３３ａのブラックマトリックスの光学像上に、他方の液晶表示パネル１３３３ｂの画素の光学像を重ね合わせる。前述のように重ね合わせることにより、表示画像の精細度が向上する。２枚の液晶表示パネルの映像信号のサンプリングタイミングを半画素分ずらせることは言うまでもない。
【０３４９】
同様に液晶表示パネル１３３３が３つ以上の場合も考えられる。その構成を図１１６に示す。９５３はダイクロイックミラーである。ランプ１１ａは赤色に発光しているとし、前記ランプからの光は液晶表示パネル１３３３ａに入射する。液晶表示パネル１３３３ａには赤色の映像信号が印加されているものとする。前記液晶表示パネル１３３３ａで変調された赤色光はダイクロイックミラー９５３ａで反射され、拡大レンズ１３３６に入射する。ランプ１１ｂは緑色に発光しているとし、液晶表示パネル１３３３ｂには緑色の映像信号が印加されているとする。前記液晶表示パネル１３３３ｂで変調された緑色光はダイクロイックミラー９５３を通過し、拡大レンズ１３３６に入射する。またランプ１１ｃは青色に発光しているとし、液晶表示パネル１３３３ｃは青色の映像信号が印加されているものとする。前記液晶表示パネル１３３３ｃで変調されて青色光はダイクロイックミラー９５３ａで反射し、拡大レンズ１３３６に入射する。観察者（図示せず）は３つの液晶表示パネル１３３３で変調されダイクロイックミラー９５３で合成された画像を見ることになる。したがって画素数は１つの液晶表示パネル１３３３の３倍の画素数となり高精細の画像表示を実現できるのである。
【０３５０】
図１２０では２つのランプ１１を用いて視角を改善する構成について説明をした。しかし、１つのランプ１１で視角を適的な方向に調整する方法がある。この方法について図９６で説明をする。視角は観察者が最も見やすい方向に設定すればよい。視角を調整するにはランプ１１と液晶表示パネル１３３３の中心軸９６１から、レンズ５５２中心を変化させればよい。つまり中心軸がずれれば、液晶表示パネル１３３３に入射する主光線の角度はかたむく。したがって、フレネルレンズ５５２の位置をｘだけずらす、もしくは、ランプ１１の位置を少し中心軸９６１からずらせばよい。ずらすことにより観察者が最適に液晶表示パネル１３３３の表示画像がみえる位置に調整することができる。この技術的思想を、本実施の形態におけるビューファインダに適用することにより最適視方向に観察者が容易に調整できる。
【０３５１】
以上のことはビューファインダだけではなく、たとえば電話器に取り付けられた表示領域９７１にも適用できる。その説明図を図９７、図９８に示す。電話器の表示領域９７１には相手先の電話番号等が表示され、前記表示はセキュリティ上他の人にはみられたくはない。本実施の形態におけるランプ１１、集光レンズ５５２、表示パネル１３３３で構成される表示装置は表示画像が見える視角（視野角）が狭い。したがって、電話をかけている本人にしか見えず、セキュリティ上効果がある。しかし、視角が狭いため最適方向に主光線の方向をむけなければ、電話を使用する当人も表示領域９７１の表示画像が見えない。たとえば、 図９８の場合、主光線の方向がａのとき、観察者Ａは表示画像が見えるが、それより背の低い観察者Ｂにはみえない。そこでランプ１１の位置、もしくは集光レンズ５５２の位置を矢印方向に移動させることにより観察者Ｂ（電話の使用者）のみがみえるようにすることができる。
【０３５２】
集光レンズ５５２の位置調整等はもちろん自動で行うこともできる。使用者が受話器９７４をとったとき、もしくはプッシュボタン部をおした時には電話本体９７３に近づいている。その時に電話器本体９７３にとりつけた赤外線ＬＥＤ９７５ａ−９７５ｄ（図９７（ｂ）参照）より赤外線を発生し、使用者にあたって反射する反射光を受光素子９７６で検出する。以上の作業により使用者の背の高さ等の概略を知ることができる。背の高さがわかれば、あらかじめ背の高さに対して設定してある移動量ｘだけ集光レンズ５５２を移動させればよい。
【０３５３】
図８３で説明したフレネルレンズ５５２および拡散シート１５を用いるという技術的思想はビューファインダのみに適用されるものではなく、図１２２（ａ）に示すような投射型表示装置にも適用できる。発光手段としてメタルハライドランプ１２２１ａが該当し、凹面鏡１２２１ｂおよびＵＶＩＲカットフィルタ１２２１ｃで照明光学系１２２１を構成する。フレネルレンズ５５２は前記照明光学系１２２１からの光を略平行光にして液晶表示パネル１３３３に入射させる。拡散シート１５、フレネルレンズ５５２の溝がスクリーン（図示せず）に投影されないようにするためのものである。投射レンズ１２２２は液晶表示パネル１３３３の変調画像をスクリーンに拡大投影する。
【０３５４】
図１２２（ａ）は液晶表示パネル１３３３にカラーフィルタ１２２３を具備させてカラー表示を行うものである。カラーフィルタ１２２３がなくとも、 図１２２（ｂ）の構成でカラー画像を表示できる。照明光学系１２２１から放射された白色光はダイクロイックミラー９５３により青，緑，赤の３つの光に分離される。液晶表示パネル１３３３にはマイクロレンズ１２２５がマトリックス状に配置されたマイクロレンズアレイ１２２４がはりつけられている。１つのマイクロレンズ１２２５は３つの画素２４４（青，緑，赤の３つので１つの組）に対応する。前記青色光はマイクロレンズ１２２４により画素２４４ｂに入射し、緑光は画素２４４ｂ，赤色光は画素２４４ｃに入射する。したがって、カラーフィルタ１２２３がなくともカラー表示を行える。
【０３５５】
本発明に関連する参考例の技術的思想は他の装置にも適用できる。たとえば、図１２３に示すメガネなし立体表示装置（３Ｄディスプレイシステム）にも応用できる。１２３１はイメージスプリッタであり液晶表示パネル１３３３の１つ１つの画素に正しく位置合せされている。発光素子（ランプ１１ａ，１１ｂ）には、それぞれ反射ミラー８３３ａまたは８３３ｂが配置されており、フレネルレンズ５５２に向かって光を放射する。各発光素子はフレネルレンズ５５２の略焦点位置に配置される。
【０３５６】
ランプ１１ａの主光線１２３２ａは、フレネルレンズ５５２（もしくは液晶表示パネル１３３３）の法線に対し角度＋θ傾いている。一方、ランプ１１ｂの主光線１２３２ｂはフレネルレンズ５５２（もしくは液晶表示パネル１３３３）の法線に対し角度−θ傾いている。イメージスプリッタ１２３１は開口部１２４１と遮光部１２４２とが交互に形成されている（図１２４参照）。遮光部１２４２はマトリックス状あるいはストライプ状が例示される。
【０３５７】
図１２４は本発明に関連する参考例の３Ｄディスプレイシステムの説明図である。液晶表示パネル１３３３にはランプ１１からの光が入射する。主として主光線１２３２ａが右眼画像１２４４の画素を通過し、主光線１２３２ｂが左眼画像１２４３の画素を通過する。イメージスプリッタ１２３１の遮光部１２４２は観察者１２４５の左眼には右眼画像１２４４の画素を通過した光が到達しないように、かつ、右眼には左眼画像１２４３の画素を通過した光が到達しないようにする働きをもつ。また、イメージスプリッタ１２３１の開口部１２４１は観察者１２４５の左眼に左眼画像１２４３の画素を通過した光が到達するように、かつ、右眼には右眼画像１２４４の画素を通過した光が到達するようにする働きをもつ。当然に左眼画像１２４３の画素には左眼用の映像を右眼画像の画素には右眼用の映像を液晶表示パネル１３３３に表示させる。これは１画素ごとに右眼用の映像信号と左眼用の映像信号とをアナログスイッチ等で切りかえて、液晶表示パネル１３３３に入力する１つの映像信号とすれば実現できる。
【０３５８】
図１２４では小型蛍光放電管を発光素子として用いるとしたが、図５２に示すように平面蛍光ランプ５２１（たとえばウシオ電機（株）品番ＵＦＵ０７Ｅ８５２）を発光素子として用いることもできる（図１２５参照）。また、図５１のＬＥＤ等も用いることが出来る。図１２５に示すように、平面蛍光ランプ５２１には、裏面に昇圧コイル１２５１が接続されている。発光素子は１つでもよい。また、フレネルレンズ５５２のかわりにプラスチック等からなる凸レンズ１２５２等を用いてもよい。集光機能としては同様であるからである。凸レンズは平面、もしくは曲率半径の大きい面を平面蛍光ランプ５２１側に向ける。これは、正弦条件を満足しやすくして、液晶表示パネル１３３３の表示画像の輝度均一性を良好にするためである。
【０３５９】
ただし、凸レンズは平凸レンズに限定するものではなく両凸レンズでもよい。また、図１２３のイメージスプリッタ１２３１としてレンチキュラスクリーン（レンズ）を用いてもよい。レンチキュラスクリーンにはかまぼこ状のレンズが形成されており、前記レンズにより左眼用の透過光と右眼用の透過光とを選択制御できることにはかわりがないからである。たとえば、レンチキュラレンズ（レンチキュラスクリーン）を液晶表示パネル１３３３に付加した構成としては図１２７の構成が例示される。
【０３６０】
図１２３はイメージスプリッタ１２３１を用いて左眼用の光と右眼用の光とを分離するものであった。同一の機能は図１３４に示すようにプリズム板１３４１を用いても実現できる。プリズム板１３４１は三角状の板である。
【０３６１】
集光手段１２５２から出射された指向性の狭い光はプリズム板１３４１に入射し、スネルの法則に従って光の進行方向を変化させられる。一つのプリズム板１３４１の三角形には２つの隣接した画素電極２４４が対応している。プリズム板１３４１を通過する"点線"の光線は右眼用の画像を表示する画素２４４ｂを通過する。一方"実線"の光線は左眼用の画像を表示する画素２４４ａを通過する。したがって、プリズム板１３４１によって右眼用と左眼用の光が形成され、アクティブマトリックス型の液晶表示パネル１３３３は一画素ごとに交互に右眼用と左眼用を表示することにより観察者は立体（３Ｄ）表示を見ることができる。
【０３６２】
なお、プリズム板１３４１の三角形のつぎ目が目立つ場合はプリズム板１３４１と液晶表示パネル１３３３間もしくは液晶表示パネル１３３３の光出射側に散乱手段（拡散板１５）を配置すればよい。したがって、ビューファインダに拡散板１５を用いるという技術的思想が３Ｄにも生かされているのである。
【０３６３】
図１３４等はプリズム板１３４１を用いて右眼用の光を左眼用の光を形成するものであった。その他図１３５に示す方法によっても実現できる。
【０３６４】
図１３５において、ランプ１２２１ａからの光は放物面鏡１２２１ｂにより略平行光の光（指向性の狭い光）に変換され出射される。出射された光はＵＶＩＲカットフィルタ１２２１ｃにより赤外線と紫外線とがカットされて可視光のみが出射される。前記光はハーフミラー１３５１により半分の光が点線のように反射され、通過した光はミラー１３５２により実線のように反射される。なお、ハーフミラー１３５１とミラー１３５２はダイクロイックミラーもしくはダイクロイックプリズムであってもよい。
【０３６５】
液晶表示パネル１３３３にはマイクロレンズアレイ１２２５が光結合剤で貼り付けられており、２つの画素２４４ａ、２４４ｂに対して１つのマイクロレンズ１２２５が対応している。マイクロレンズ１２２５により点線の光は画素２４４ａを通過し、実線の光は画素２４４ｂを通過する。これが左眼用の光と右眼用の光となる。以上のように構成すれば、図１２４と同様に３Ｄ表示を行うことができる。
【０３６６】
以上の３Ｄディスプレイシステムは、一つの液晶表示パネル１３３３において一画素ごとに左眼用の画像と右眼用の画像を交互に表示するものであった。しかし、前記構成では片目について考えれば液晶表示パネルの画素数の１／２しか見えないことになる。つまり液晶表示パネルの画素数が１／２の表示画面をみているのと同様となる。
【０３６７】
この課題を解決する３Ｄディスプレイシステムの構成を図１２９に示す。イメージスプリッタ１２３１等に採用していない。２つのランプ１１の主光線が液晶表示パネル１３３３の法線に対してθの角度傾いている点、集光手段（レンズ１２５２）がランプ１１が放射する光を指向性の狭い光に変換する点は図１２３と同様である。つまり、主としてランプ１１ａからの光は左眼用の光となり、発光素子１１ｂからの光は右眼用の光となる。十分、液晶表示パネル１３３３から出射される光の指向性が狭いからである。液晶表示パネル１３３３としてはアクティブマトリックス型のＴＮ液晶表示パネルを採用する。
【０３６８】
図１３１は液晶表示パネル１３３３に印加する映像信号を作製する回路のブロック図である。再生装置ａ、再生装置ｂは、水平走査期間（Ｈ期間）で同期をとって映像信号を出力できるものである。同期は同期回路１３１１により行なう。これらの同期をとる方法、装置は映像分野の当事者であれば容易に構成できるので説明を省略する。再生装置ａおよびｂから読みだした映像信号は、Ａ／Ｄ変換器１３１３によりアナログ−デジタル変換され、ＳＲＡＭからなるメモリ１３１４ａ、１３１４ｂにデータとして保持される。メモリａ、ｂからは切り換え回路１３１５のスイッチを切り換えることにより選択的に読み出す。読み出された映像データはＤ／Ａ変換器１３１６によりデジタル−アナログ変換され、かつ水平同期信号等を付加されビデオ信号となり図１９のスイッチＳＷ１のａ端子に加えられる。
【０３６９】
メモリａからの読み出しは１フィールド（１Ｆ）の１／２期間（倍速読み出し）で読み出す。残りの１／２期間は０データ（映像データなし＝黒表示（無表示））がＤ／Ａ変換器１３１６に転送される。同様にメモリｂからの読み出しは１フィールド（１Ｆ）の１／２期間で読み出し、残りの１／２期間は０データ（映像データなし＝黒表示（無表示））がＤ／Ａ変換器１３１６に転送される。つまり、第１フィールドの１／２期間は左眼用の映像信号が、残りの１／２期間が無表示に、次の第２フィールドの１／２期間は右眼用の映像信号が、残りの１／２期間が無表示のビデオ信号がＤ／Ａ変換器１３１６から出力されるのである。なお、前述で１／２期間としたのは説明の便宜のためおよび回路構成の容易性のためであり、これに限定するものではない。たとえば３／４期間に映像信号が、残りの１／４期間が無表示であってもよい。また、１フィールドに限定するものでもなく、１フレームであってもよい。たとえば、１フレームの１／２期間（＝２フィールド）に左眼用の映像信号が、残りの１／２期間が無表示であってもよい。ただし、左眼用の映像信号が表示される間隔が長くなるとフリッカが発生する、あるいは表示画像に連続性がなくなり動画がぎこちなくなるという問題が発生する。静止画の場合は映像信号の表示間隔が長くなってもよいが動画表示の場合は問題となるであろう。この意味からも、左眼用の映像信号の出現間隔は１フレーム（＝２フィールド）ことが好ましい。
【０３７０】
図１３０は液晶表示パネル１３３３の画像表示状態と２つの発光素子１１ａ、１１ｂの点灯タイミング及び液晶表示パネル１３３３の画素電極に印加する信号極性とを図示したものである。
【０３７１】
まず、液晶表示パネル１３３３の表示状態について説明する（図の左から２列目）。（１）は無表示状態を示す（なお、無表示状態は、液晶表示パネルの有効表示領域を斜線で示す）。また、映像表示は説明を容易にするため"Ｆ"の文字を例とし、左眼用の表示は実線で右眼用の表示は点線で示すものとする。（２）において表示画面の上から順次映像が表示され、（３）は一画面全体が表示された状態を示す。次に（４）では画面の上方向から無表示状態となっていく。（５）は完全に無表示（黒表示）となった状態を示す。なお、（２）から（５）は量子的に移りかわるのではなく連続して行なわれる。つまり、液晶表示パネル１３３３はゲートドライブ回路（図示せず）が１水平走査期間（１Ｈ）ごとにゲート信号線にＴＦＴのオン電圧を印加し、順次、ゲート信号線にオン電圧を走査することにより行なう。
【０３７２】
（２）から（５）において任意の画素は１フィールド（１Ｆ）の期間の１／２時間映像表示されていることになる。また、この時は、左眼用発光素子１１ａが点灯（オン）し、右眼用発光素子１１ｂが消灯（オフ）する。したがって、液晶表示パネル１３３３には左眼用の映像表示されており、前記発光素子１１ａが放射する光により前記映像表示の光学像が観察者の左眼に到達する。黒表示（無表示）とするのは、アクティブマトリックス型液晶表示パネル（というよりは、液晶表示パネル）はメモリ性があるからである。メモリ性とは画素電極２４４に書き込まれた信号は、次に前記画素電極２４４に信号が印加されるまで保持される性質をいう。もし、黒表示を行なわなければ、左眼用の表示と右眼用の表示が液晶表示パネル１３３３に同時に表示される状態がおこるからである。同時に表示されれば左眼用ランプ１１ａと右眼用ランプ１１ｂを交互にオンオフさせても、左眼用の映像が右眼に、右眼用の映像が左眼に到達し、３Ｄ表示とはならない。図１３０に示すように、左眼用の映像を表示した後、いったんすべての画素電極２４４に保持された電圧をリセット（消去）し、新たに右眼用の映像を表示すれば、左眼用の映像と右眼用の映像をそれぞれ選択的に左眼、右眼に到達させることができる。
【０３７３】
（６）から（９）は右眼用の映像を表示していることを示している。その際左眼用ランプ１１ａは消灯（オフ）し、右眼用ランプ１１ｂが点灯（オン）させる。液晶表示パネル１３３３には画面の上端から右眼用の映像を表示させていき、（７）のように完全に右眼用の映像を表示させた後、（８）の如く上部より黒表示にしていく。上記（２）から（５）の状態（左眼用の映像表示状態）と、（６）から（８）の状態（右眼用の映像表示状態）を１フレームごとに繰り返す。
【０３７４】
なお、左眼用ランプ１１ａは（２）の表示状態で点灯させるとしたがこれに限定するものではなく、（１）の表示状態のように点灯させてもよい。同様に右眼用ランプ１１ｂは（５）の表示状態で点灯させてもよい。
【０３７５】
図１３０の左端欄は画素電極２４４に印加する信号の極性を示している。対向電極２４３の電位に対して正極性を"＋"で、負極性を"−"で示している。一画素電極２４４の行（横方向）には同一極性の信号を印加する。また、一行ごとに極性を反転させる。つまり、図１３０（ａ）において画素電極７４ａと７４ｂとは同一極性が、画素電極２４４ａと２４４ｃとは反対極性の信号が印加される。
【０３７６】
次のフィールド（図１３０（ｂ））では各画素電極の信号極性は、前のフィールド（図１３０（ａ））と逆となるようにする。つまり、図１３０（ａ）の画素電極２４４ｃは"−"極性が印加されているが、図１３０（ｂ）では"＋"極性が印加される。このように１フィールドごとに画素電極２４４に印加する信号極性を反転させることにより、フリッカの発生を防止でき、良好な画像表示を実現できる。
【０３７７】
図１３０は集光手段（レンズ１２５２）を用いて、ランプ１１ａが放射する光を左眼に、ランプ１１ｂが放射する光を右眼に入射させるものであった。前記集光手段のかわりに図１２７に示すようにレンチキュラレンズ１２７１を用いても、同様の３Ｄ表示を実現できる。なお、液晶表示パネル１３３３の映像表示状態および発光素子（ランプ１１ａ、１１ｂ）の発光状態等に図１３０に示したのと同様である。ただし、ランプ１１ａと１１ｂはいれかえて考える必要があるが基本的な問題はない。
【０３７８】
図１２８にレンチキュラレンズ１２７１部を通過する光路等の説明図である。レンチキュラレンズ１２７１ａは光結合剤９０１ａを介してアレイ基板２４２とオプティカルカップリング（ＯＣ）されており、また、レンチキュラレンズ１２７１ｂは光結合剤９０１ｂを介して対向基板２４１とＯＣされている。これは界面反射等を防止する等のためである。
【０３７９】
ランプ１１ａから放射された光（実線）はレンチキュラレンズ１２７１ａに入射し、液晶表示パネル１３３３の画素電極２４４を通過してかつ、レンチキュラレンズ１２７１ｂで屈折されて右眼に入射する。一方、ランプ１１ｂから放射された光（点線）はレンチキュラレンズ１２７１ａに入射し、同様に液晶表示パネル１３３３の画素電極２４４を通過し、かつレンチキュラレンズ１２７１ｂで屈折されて左眼に入射する。
【０３８０】
以上のことから、ランプ１１ａと１１ｂから放射される光は右眼および左眼に選択的に到達させることができることが理解できる。つまりレンチキュラレンズ１２７１は図１２９の集光手段（レンズ１２５２）と同様の機能を有する。したがって、図１３０の表示方法を実施すれば３Ｄ表示を行えるのである。
【０３８１】
ランプを２つ具備するという技術的思想は図１３９の構成でも実現できる。遮光板１３９３、遮光パターン１３９２には、１つのマイクロレンズ１２２５に対し、２つの微小穴（１３９１ａ、１３９１ｂ）を形成されている。穴１３９１ａから放射する光をマイクロレンズ１２２５により右眼用の光とし、穴１３９１ｂから放射する光を同様にマイクロレンズ１２２５により左眼用の光とする。以上のようにすれば１枚のマイクロレンズアレイ１２２４で指向性の良好な左眼用の光と右眼用の光を作製できる。またマイクロレンズアレイでなくとも図１２６のセルホック（円筒）レンズアレイでも実現できる。
【０３８２】
本発明に関連する参考例の３Ｄディスプレイでは点光源とみなせるランプ１１を用いているため、液晶表示パネル１３３３を出射する光の指向性が狭い。したがって、左眼用と右眼用の光を良好に分離することができる。また、２つのランプ１１から放射される主光線の角度を＋θおよび−θとすることにより、観察者が液晶表示パネル１３３３の画面中央部で良好に表示画像を見ることができる。また、主光線の角度を変化させることは容易である。また、ランプ１１の位置を変化させることも容易である。たとえば、図３３の点線位置に発光素子（ランプ１１）を移動させれば、表示パネル２２３の表示画像を斜め方向からみたときに３Ｄ表示になるようにすることができる。
【０３８３】
ランプを２つ具備する３Ｄディスプレイシステムでは、観察者が最適に３Ｄ画像を見えるように調整することが容易である。図１３２に示すようにランプ１１から放射される角度θを調整すればよい。たとえば、図１３２（ａ）で示すように表示パネル１３３３の表示画面から観察者の眼１４０１が比較的離している時（比較的遠くから表示画面を見ている時）は角度θ₁を小さくする。一方、図１３２（ｂ）のように観察者の眼１４０１が比較的、表示画面に近いときは角度θ２を大きくすればよい。
【０３８４】
より具体的に図１３３のように構成をする。アーム１４１２ａ、１４１２ｂには反射ミラー８３３を有するランプ１１がビス１４１１ａ、１４１１ｂが取り付けられており、前記アーム１４１２の一端はビス１４１１ｃで調整板１４１４に取り付けられている。また、ビス１４１１ａ、１４１１ｂによりスライド板１４１３の穴にアーム１４１２が取り付けられている。
【０３８５】
調整板１４１４を右方向に引っぱることにより２つのランプ１１間がひらく。また、押し込むことによりランプ１１間の距離はせばまる。以上のように調整板１４１４を観察者が調整することにより、最適に３Ｄ表示が見られるようにすることが容易にできる。
上述のビューファインダは、発光素子の小さな発光体から広い立体角に放射される光をフレネルレンズ又は放物面鏡等で平行に近く指向性の狭い光に変換し、 液晶表示パネル１３３３で変調して画像を表示するので、消費電力が少なく、輝度むらも少ない。しかも、ランプ１１の駆動回路も従来のビューファインダのようにバックライトを用いるものに比較して単純な構成となるため、コンパクトで軽量のビューファインダを提供できる。液晶表示パネルとしてＰＤ液晶表示パネルを用いれば、ＴＮ液晶表示パネルに比較して消費電力をさらに低減できる。
また、フレネルレンズ５２２等と液晶表示パネル１３３３間に拡散板１５を配置することにより、液晶表示パネル１３３３の画素２４４とフレネルレンズ５２２の溝とが干渉してモアレを生ずることを、また、フレネルレンズの溝が視覚的に認識されることを抑制できるから良好な画像表示を実現できる。その上、拡散板１５をＰＤ液晶表示パネルとすることにより任意の視野角および表示画像のブライトネス（輝度、明るさなど）調整を行なうことができる。また、ランプ１１として点光源とみなせるものを使用できるから、良好な３Ｄ表示をも実現できる。
【発明の効果】
以上述べたところから明らかなように、本発明は、たとえば表示品位の向上された液晶表示装置およびそれを用いたビューファインダとカメラを提供することができる。
【図面の簡単な説明】
【図１】本発明に関連する参考例のビューファインダの断面図である。
【図２】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図３】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図４】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図５】本発明に関連する参考例のビューファインダの説明図である。
【図６】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図７】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図８】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図９】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１０】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１１】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１２】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１３】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１４】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１５】本発明に関連する参考例のビューファインダの説明図である。
【図１６】本発明に関連する参考例のランプの駆動方法の説明図である。
【図１７】本発明に関連する参考例のランプの駆動方法の説明図である。
【図１８】本発明に関連する参考例のランプの駆動方法の説明図である。
【図１９】本発明に関連する参考例のランプの駆動方法の説明図である。
【図２０】本発明に関連する参考例のランプの駆動方法の説明図である。
【図２１】本発明に関連する参考例のビューファインダの説明図である。
【図２２】本発明に関連する参考例のビューファインダの説明図である。
【図２３】高分子分散液晶表示パネルの断面図である。
【図２４】高分子分散液晶表示パネルの説明図である。
【図２５】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図２６】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図２７】本発明に関連する参考例のビューファインダの断面図である。
【図２８】本発明に関連する参考例のビューファインダのランプの説明図である。
【図２９】本発明に関連する参考例のビューファインダのランプの断面図である。
【図３０】本発明に関連する参考例のビューファインダのランプの断面図である。
【図３１】本発明に関連する参考例のビューファインダのランプの説明図である。
【図３２】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図３３】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図３４】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図３５】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図３６】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図３７】本発明に関連する参考例のビューファインダのランプの説明図である。
【図３８】本発明に関連する参考例のビューファインダの光源部の斜視図である。
【図３９】本発明に関連する参考例のビューファインダの光源部の斜視図である。
【図４０】本発明に関連する参考例のビューファインダの光源部の斜視図である。
【図４１】本発明に関連する参考例のビューファインダの光源部の斜視図である。
【図４２】本発明に関連する参考例のランプの駆動方法の説明図である。
【図４３】本発明に関連する参考例のビデオカメラの説明図である。
【図４４】本発明に関連する参考例のビデオカメラの説明図である。
【図４５】本発明に関連する参考例のランプの駆動方法の説明図である。
【図４６】本発明に関連する参考例のランプの駆動方法の説明図である。
【図４７】本発明に関連する参考例のビューファインダのランプの説明図である。
【図４８】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図４９】本発明に関連する参考例のビューファインダのランプの駆動方法の説明図である。
【図５０】ＬＥＤの説明図である。
【図５１】ＬＥＤの説明図である。
【図５２】蛍光面発光素子の説明図である。
【図５３】本発明に関連する参考例のビデオカメラの説明図である。
【図５４】本発明に関連する参考例の電子スチルカメラの説明図である。
【図５５】本発明に関連する参考例のビューファインダの断面図である。
【図５６】本発明に関連する参考例のビューファインダの断面図である。
【図５７】本発明に関連する参考例のビューファインダの説明図である。
【図５８】本発明に関連する参考例のビューファインダの説明図である。
【図５９】本発明に関連する参考例のビューファインダの説明図である。
【図６０】本発明に関連する参考例のビューファインダの説明図である。
【図６１】本発明に関連する参考例のビューファインダの説明図である。
【図６２】本発明に関連する参考例の表示装置の説明図である。
【図６３】本発明に関連する参考例の表示装置の説明図である。
【図６４】本発明に関連する参考例のビューファインダの説明図である。
【図６５】本発明に関連する参考例のビューファインダの説明図である。
【図６６】本発明に関連する参考例のビューファインダの説明図である。
【図６７】本発明に関連する参考例のビューファインダの説明図である。
【図６８】本実施の形態のビューファインダの説明図である。
【図６９】本実施の形態のビューファインダの説明図である。
【図７０】本実施の形態のビューファインダの説明図である。
【図７１】本実施の形態のビューファインダの説明図である。
【図７２】本実施の形態のビューファインダの説明図である。
【図７３】本実施の形態のビューファインダの説明図である。
【図７４】本実施の形態のビューファインダの説明図である。
【図７５】本実施の形態のビューファインダの説明図である。
【図７６】本実施の形態のビューファインダの説明図である。
【図７７】本実施の形態のビューファインダの説明図である。
【図７８】本実施の形態のビューファインダの説明図である。
【図７９】本実施の形態のビューファインダの説明図である。
【図８０】本実施の形態のビューファインダの説明図である。
【図８１】本発明に関連する参考例のビューファインダの説明図である。
【図８２】本発明に関連する参考例のビューファインダの斜視図である。
【図８３】本実施の形態のビューファインダの断面図である。
【図８４】本実施の形態のビューファインダの断面図である。
【図８５】本実施の形態のビデオカメラの説明図である。
【図８６】本実施の形態のビューファインダの説明図である。
【図８７】本発明に関連する参考例のビューファインダの説明図である。
【図８８】本発明に関連する参考例のビューファインダの説明図である。
【図８９】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図９０】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図９１】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図９２】本発明に関連する参考例のビューファインダの説明図である。
【図９３】本発明に関連する参考例のビューファインダの説明図である。
【図９４】本発明に関連する参考例のビューファインダの説明図である。
【図９５】本発明に関連する参考例のビューファインダの断面図である。
【図９６】本実施の形態のビューファインダの説明図である。
【図９７】本発明に関連する参考例の表示パネルの説明図である。
【図９８】本発明に関連する参考例のビューファインダの説明図である。
【図９９】本発明に関連する参考例のビューファインダの断面図である。
【図１００】本発明に関連する参考例のビューファインダの断面図である。
【図１０１】本発明に関連する参考例のビューファインダの説明図である。
【図１０２】本発明に関連する参考例のビューファインダの説明図である。
【図１０３】本発明に関連する参考例のビューファインダの説明図である。
【図１０４】本発明に関連する参考例のビューファインダの説明図である。
【図１０５】本発明に関連する参考例のビューファインダの説明図である。
【図１０６】本発明に関連する参考例のビューファインダの説明図である。
【図１０７】本発明に関連する参考例のビューファインダの断面図である。
【図１０８】本発明に関連する参考例のビューファインダの断面図である。
【図１０９】本発明に関連する参考例のビューファインダの断面図である。
【図１１０】本発明に関連する参考例のビューファインダの断面図である。
【図１１１】本発明に関連する参考例のビューファインダの断面図である。
【図１１２】本発明に関連する参考例のビューファインダの説明図である。
【図１１３】本発明に関連する参考例のビューファインダの説明図である。
【図１１４】本実施の形態のビューファインダの説明図である。
【図１１５】本発明に関連する参考例のビューファインダの説明図である。
【図１１６】本実施の形態のビューファインダの断面図である。
【図１１７】本発明に関連する参考例のビューファインダの斜視図である。
【図１１８】本発明に関連する参考例のビューファインダの断面図である。
【図１１９】本発明に関連する参考例のビューファインダの断面図である。
【図１２０】本発明に関連する参考例のビューファインダの説明図である。
【図１２１】本発明に関連する参考例のビューファインダの説明図である。
【図１２２】本発明に関連する参考例の表示装置の構成図である。
【図１２３】本発明に関連する参考例の表示装置の説明図である。
【図１２４】本発明に関連する参考例の表示装置の説明図である。
【図１２５】本発明に関連する参考例の表示装置の説明図である。
【図１２６】本発明に関連する参考例の表示装置に用いるレンズの説明図である。
【図１２７】本発明に関連する参考例の表示装置の説明図である。
【図１２８】本発明に関連する参考例の表示装置の説明図である。
【図１２９】本発明に関連する参考例の表示装置の説明図である。
【図１３０】本発明に関連する参考例の表示装置の説明図である。
【図１３１】本発明に関連する参考例の表示装置の駆動方法の説明図である。
【図１３２】本発明に関連する参考例の表示装置の駆動方法の説明図である。
【図１３３】本発明に関連する参考例の表示装置の説明図である。
【図１３４】本発明に関連する参考例の表示装置の説明図である。
【図１３５】本発明に関連する参考例の表示装置の構成図である。
【図１３６】ビューファインダの外観図である。
【図１３７】従来のビューファインダの断面図である。
【図１３８】従来のビューファインダの光源部の説明図である。
【図１３９】本発明に関連する参考例のビューファインダの説明図である。
【図１４０】本発明に関連する参考例のビューファインダの設計例である。
【図１４１】本発明に関連する参考例のビューファインダの設計例である。
【図１４２】本発明に関連する参考例のビューファインダの設計例である。
【図１４３】本発明に関連する参考例のビューファインダの設計例である。
【図１４４】本発明に関連する参考例のビューファインダの放物面鏡の設計例である。
【符号の説明】
１１ ランプ
１２ 放物面鏡
１４ ベース基板
１５ 拡散（散乱）シート
１６ ランプ電位端子
１６ａ，ｂ フィラメント端子
１６ｃ アノード端子
１７ ランプ用回路部品
２０ 封止部材
２１，２１ａ ランプケース
２２ 反射面
２３ 蛍光体
２４ フィラメント
２５ アノード電極
２６ 緩衝部材
２７ ソケット
２８ 端子
２９ ハンダ
３０，３０ａ 突起
３１ 反射膜
３２ 光反射筒
１５ａ 拡散板
４３ エンボス加工面
５１ 光線
５２ 有効表示領域
７１ 低輝度部
７２ ゴムキャップ
７３ 突起
９１ 反射膜
１０１ 集光キャップ
１０２ 集光プリズム
１０３ 接着剤
１０４ 透明樹脂
１０５ 反射筒
１０６ 拡散板
１０７ 反射キャップ
１１１ 透明導電膜（ＩＴＯ）
１１２ 帯電防止膜
１２１ 導線
１３１ 金網
１６１ タイマー回路
１６２ 可変電源
１６３ 可変抵抗（可変電流素子）
１７１ インバータ
１７２ａ，ｂ アナログスイッチ
１７３ａ，ｂ 電流制限抵抗
１８１ ホトセンサ
１８２ オペアンプ
１８３ 光検出回路
１８４ 発振回路
１８５ 増幅器
１９１ アンプ
１９２ 位相分割回路
１９３ 出力切り換え回路
１９４ ドライブ回路制御部
１９５ ソースドライブ回路
１９６ ゲートドライブ回路
１９７，１９８ 電源
２０１ａ，ｂ ＤＣＤＣコンバータ
２０２ バッテリー
２０４ 電流検出回路
２１１ 外ワク
２１２ 絞りつまみ
２１３ 虹彩絞り
２４９ ソース信号線
２３０ カラーフィルタ
２３１ 透明樹脂
２４１ 対向電極基板
２４２ アレイ基板
２４３ 対向電極
２４４ 画素電極
２４５ 水滴状液晶
２４６ ポリマー
２４７ 入射光
２４８ 光変調層（液晶層）
２９１ 保護膜（ＳｉＯ₂）
３０１ 取付ガラス
３１１ 発光領域
３１２ マーカ
３１３ くぼみ部
３１４ 透明突起
３３１ 拡散（散乱）部
３３２ 拡散（散乱）点
３８１ 透明ホルダー（樹脂樹脂）
３８２ ホルダー固定部
３９１ 放物面鏡
４０１ 凸部
４１１ 拡散（散乱）板
４２１ サーミスタ
４２２ コンパレータ
４２３ ＣＰＵ
４２４ スイッチ回路
４２５ オペアンプ
４２６ ＦＥＴ
４３１ ビデオカメラ本体
４３２ 撮像レンズ部
４３３ スイッチ（ＳＷ）
４３４ 接続部
４３５ 録画スイッチ
４７１ 封止樹脂
５０１ 端子
５０２ 発光体
５０３ 樹脂レンズ
５０４ レンズ面
５０５ レンズ面の頂点
５０６ レンズ面の法線
５０７ レンズ面の曲率中心
５０８ レンズ面による発光体の像
５２１ 面発蛍光ランプ
５３１ ＣＣＤセンサ
５３２ 発光素子電源回路
５３３ 液晶表示パネル駆動回路
５３４ 再生回路
５４１ スチルカメラ本体
５５１ 反射板
５５２ 照明レンズ（凸レンズ）
５５３ 補助レンズ
６０１ レンズ面
６０２ フレネル面
６０３ 凸レンズ
６０４ フレネルレンズ
６１１ 平面部
６２１ 導光板
６２２ 拡散部
６３１ プリズム板
６４１ アイポイント
６８１ パネルホルダー
６９１ 表示部
７１１ ソケット
７１２ つまみ
７１３ 収縮部１
７１４ 収縮部２
７１５ 光軸
７５１ ミラー
８１１ 挿入部
８２１ つまみ
８３１ 反射板
１３３６ｂ 凹レンズ
８５１ 留め具
８６１ パネル取付部
８６２ ジャバラ
８６３ 回転軸
８６４ レンズ取付部
８７１ ケース
８７２ 光線
８８１ シリンドリカルレンズ
８８２ 小型蛍光管
８８３ 反射板
９０１ 透明接着剤
９１１ だ円面鏡
９１２ 遮光板
９２１ 拡散部
９３１ 円形絞り
９３２ 回折格子
９５１ 光合成面
９５２ ＰＢＳ
９５３ ダイクロイックミラー
９６１ 光軸
９７１ 表示領域
９７２ プッシュボタン部
９７３ 電話器本体
９７４ 受話器
９７５ 赤外線ＬＥＤ
９７６ 受光素子
９９１ 取付ホルダー
１０１１ 透明基板
１０１２ 光吸収膜
１０２２，１０２３，１０２４，１０３１ 界面
１０３１ 界面
１０４１ ＰＤ液晶表示パネル
１０４２ 信号発生源
１０４３ 信号振幅可変器
１０４４ 封止樹脂
１０４５ ガラス基板
１０４６ ＩＴＯ電極
１０４７ ＰＤ液晶層
１０５１ 光結合層
１０９１ 絞り
１１１１ 導光体
１１２１ 反射膜
１１３１ 光ファイバー
１１４１ 太陽光
１１４２ ホトセンサ
１１４３ フレネルレンズ
１１５１ ヒステリシスコンパレータ回路
１１５２ 光検出回路
１１５３ スイッチ回路
１１７１ 遮光カバー
１２１１ 反射型フレネルレンズ
１２２１ 光源
１２２１ａ メタルハライドランプ
１２２１ｂ 凹面鏡
１２２１ｃ ＵＶＩＲカットミラー
１２２２ 投射レンズ
１２２３ カラーフィルタ
１２２４ マイクロレンズアレイ
１２２５ マイクロレンズ
１２３１ イメージスプリッタ
１２３２ 主光線
１２４１ 開口部
１２４２ 遮光部
１２４３ 左目画像
１２４４ 右目画像
１２４５ 観察者
１２５１ 昇圧コイル
１２５２ 集光レンズ（凸レンズ）
１２６１ セルホックレンズ
１２７１ レンチキュラレンズ
１３１１ 同期回路
１３１２ 再生装置
１３１３ Ａ／Ｄ変換回路
１３１４ フレームメモリ
１３１５ 切り換え回路
１２１６ Ｄ／Ａ変換回路
１４０１ａ 右眼
１４０１ｂ 左眼
１４１１ ビス
１４１２ アーム
１４１３ スライド板
１４１４ 調整板
１３４１ プリズム板
１３５１ ハーフミラー
１３５２ ミラー
１３２１ ボデー
１３２３ 取付金具
１３３１ 蛍光管ｂｏｘ
１３３２ 接眼カバー
１３３３ 液晶表示パネル
１３３４ 偏光板
１３３５ 取付ホルダー
１３３６ 拡大レンズ
１３４１ 蛍光管の発光パターン[0001]
BACKGROUND OF THE INVENTION
The present inventionFor liquid crystal display devices and viewfinders and cameras using themIt is related.
[0002]
[Prior art]
The liquid crystal display panel is actively researched and developed because it has a high possibility of being lighter and thinner than a display device using a CRT. In recent years, a twisted nematic mode (TN mode) liquid crystal display device in which the optical rotation of liquid crystal is applied to image display has been put into practical use and used in portable pocket TVs, video camera viewfinders, and the like.
[0003]
Hereinafter, a conventional viewfinder will be described. In this specification, at least a light source (light generation means) such as a light emitting element and an image display device (light modulation means) such as a liquid crystal display panel are provided, and the viewfinder is configured by integrating both. Call. Therefore, the viewfinder of the present invention does not mean only the viewfinder of a video camera. For example, a display device such as a pocket TV, an image display device of an electronic still camera, and a head mounted display are also included. The light source includes all self-luminous lamps such as a hot cathode lamp, a cold cathode lamp, a PDP, and an LED.
[0004]
An example of the appearance shape of the viewfinder is shown in FIG. FIG. 137 shows a cross-sectional view of a conventional viewfinder. Reference numeral 1321 denotes a body, 1322 denotes an eyepiece cover, 1335 denotes an eyepiece ring, and 1333 denotes a twisted nematic (TN) liquid crystal display panel. A polarizing plate 1334 is disposed on the input / output surface of the liquid crystal display panel 1333. The body 1321 stores a liquid crystal display panel 1333 and a backlight 1331 as a light source. A magnifying lens 1336 is disposed inside the eyepiece ring 1335. By adjusting the insertion degree of the eyepiece ring 1335, the focus can be adjusted in accordance with the visual acuity of the observer.
[0005]
The TN liquid crystal display panel 1333 has a liquid crystal layer 248 with a film thickness of about 4 to 5 μm, and has a mosaic color filter. Further, polarizing plates 1334 functioning as a polarizer 1334a and an analyzer 1334b are disposed on both sides of the TN liquid crystal display panel 1333, respectively. The viewfinder is attached to the video camera main body 421 by a mounting bracket 1323. It should be noted that some drawings are omitted or / and enlarged or reduced for easy understanding, explanation and / or drawing. For example, the eyepiece cover 1322 and the like are omitted in the cross-sectional view of the viewfinder in FIG. The same applies to the following drawings.
[0006]
A perspective view of the main elements shown in FIG. 136 is shown in FIG. The light source includes a fluorescent tube box 1331 in which a fluorescent tube is disposed, and a diffused light scattering plate 1332 disposed on the entire surface. The diffusion plate 1332 is used for diffusing the light emitted from the fluorescent plate box 1331 to obtain a surface light source with uniform luminance.
[0007]
A rod-like fluorescent tube is used as the light generating means of the conventional viewfinder. A fluorescent tube having a diameter of 2 to 5 mm is used when the diagonal length of the display screen of the liquid crystal display panel 1333 is about 1 inch. When the diagonal length of the display screen of the liquid crystal display panel 1333 is 1 inch or more, a plurality of the fluorescent tubes are often used. Light is emitted forward and backward from the fluorescent tube. A diffusion plate is disposed between the fluorescent tube and the TN liquid crystal display panel 1333. The diffusion plate 1332 diffuses the light from the fluorescent tube to form a surface light source. A surface light source is formed by the diffusion plate 1332, and light from the surface light source enters the liquid crystal display panel 1332. The light divergence area of the surface light source is equal to or larger than the image display area (effective display area) of the liquid crystal display panel 1333. There is also a light emitting element that forms a surface light source without using a fluorescent tube and a diffusion plate 1332. It is normally called a flat fluorescent lamp, and is manufactured and sold by Ushio Electric Co., Ltd. (for example, product name, UFU07F852, etc.).
[0008]
Polarizers 1334a and 1334b are disposed in front of and behind the liquid crystal display panel 1333, respectively. A polarizing plate 1334a (polarizer) disposed between the diffusion plate 1332 and the TN liquid crystal display panel 1333 has a function of converting random light from the surface light source into linearly polarized light. A polarizing plate 1334b (analyzer) disposed between the TN liquid crystal display panel 1333 and the viewer of the display screen has a function of blocking the light according to the degree of modulation of light incident on the TN liquid crystal display panel 1333. Usually, the polarizer 1334a and the analyzer 1334b are arranged so that the polarization directions are orthogonal (normally white display).
[0009]
As described above, light from the light emitting element is scattered by the diffusion plate 1334, and a surface light source is formed. Light from the surface light source is converted into linearly polarized light by a polarizer 1334a. The TN liquid crystal display panel 1333 modulates the linearly polarized light based on the applied video signal. The analyzer 1334b blocks or transmits light according to the degree of modulation. An image is displayed as described above. The display image can be enlarged and viewed by a magnifying lens 1335 disposed between the analyzer 1334b and the observer.
[0010]
[Problems to be solved by the invention]
Video cameras are required to be compact and lightweight in terms of portability and operability. Therefore, liquid crystal display panels are being introduced as viewfinder displays. However, at present, the power consumption of a viewfinder using a liquid crystal display panel is considerably large. For example, the power consumption of a viewfinder using a TN liquid crystal display panel with an effective display area of 0.7 inches is 0.4 W for the TN liquid crystal display panel and its drive circuit, and about 0.6 W for the light source, There is an example of .0W. The video camera has a limited battery capacity in order to ensure compactness and lightness. When the power consumption of the viewfinder is large, the continuous use time is shortened, which is a serious problem. In recent years, in particular, there has been a demand for downsizing of a video camera, and as a result, the capacity of a battery that can be loaded is limited, and it is becoming indispensable to realize low power consumption of a viewfinder.
[0011]
In addition, the light box 1331 made of a fluorescent tube and a reflecting plate needs to be a surface light source with little luminance unevenness. Therefore, a diffusion plate 372 is disposed between the TN liquid crystal display panel 1333 and the fluorescent tube. When a diffuser plate 1334 having a low light diffusivity is used, a light emission pattern 1341 of a fluorescent tube appears as shown in FIG. 57, which can be seen through the display screen of the liquid crystal display panel 1333, and the display quality is lowered. For this reason, a diffuser plate 1334 having a high diffusivity is used, but generally the light transmittance of the diffuser plate 1334 decreases when the diffusivity is increased. The only way to obtain the required brightness is to increase the amount of light output from the light source. This causes an increase in power consumption of the light source.
[0012]
The size of the light emitting element is also an issue. In order to obtain a surface light source, at least the light emitting area needs to be larger than the area of the effective display area of the liquid crystal display panel 1333. Therefore, it is naturally large. Another problem is that the input voltage of the fluorescent lamp is high. Usually, it is necessary to use a DC voltage of about 5 V as an AC voltage of 100 to 200 V using an inverter and a booster coil. The total power efficiency of the inverter and booster coil is only about 80%, and power loss occurs here. Of course, the step-up coil is also large and requires a considerable volume. As an example, a module size (product name UFU07F852) combining a flat fluorescent lamp for 0.7 inch liquid crystal display panel and a booster coil manufactured by Ushio Electric Co., Ltd. has a width of 22.7 mm, a height of 22.8 mm and a depth of 11.3 mm. There is also a heavy weight because it is made of glass. In addition, since a high AC voltage is used, unnecessary radiation is large, causing a beat failure in the display image of the liquid crystal display panel. Furthermore, there is a problem that the fluorescent tube (cold cathode type) does not light in the dark state and does not light when the temperature is low. Further, the heat generation is large, and the liquid crystal display panel 1333 is liable to be adversely affected.
[0013]
The purpose of the present invention is toConsidering the above conventional problems, for example, a liquid crystal display device with improved display quality, and a viewfinder and a camera using the sameIs to provide.
[0014]
[Means for Solving the Problems]
  A liquid crystal display device of a technique related to the present invention includes a light emitting element,
  A liquid crystal display panel that modulates light emitted by the light emitting element;
  A magnifying lens for enlarging a display image of the liquid crystal display panel;
  A positive lens disposed between the magnifying lens and the liquid crystal display panel;
  The liquid crystal display device is characterized in that a space between the liquid crystal display panel and the positive lens is sealed.
  A liquid crystal display device of a technique related to the present invention includes a light emitting element,
  A liquid crystal display panel that modulates light emitted by the light emitting element;
  A magnifying lens for enlarging a display image of the liquid crystal display panel;
  A first positive lens disposed between the light emitting element and the liquid crystal display panel;
  A second positive lens disposed between the magnifying lens and the liquid crystal display panel;
  The first positive lens converts light emitted from the light emitting element into substantially parallel light and irradiates the liquid crystal display panel;
  The second positive lens is a liquid crystal display device that focuses the principal ray direction of light that has passed through the liquid crystal display panel.
  A liquid crystal display device of a technique related to the present invention includes a light emitting element,
  A liquid crystal display panel that modulates light emitted by the light emitting element;
  A magnifying lens for enlarging a display image of the liquid crystal display panel;
  A positive lens disposed between the light emitting element and the liquid crystal display panel;
  The liquid crystal display device can switch between a first state in which the light emitting element is disposed on the optical axis and a second state in which the light emitting element is removed from the optical axis.
  A liquid crystal display device of a technique related to the present invention includes a light emitting element,
  A liquid crystal display panel that modulates light emitted by the light emitting element;
  A positive lens disposed between the light emitting element and the liquid crystal display panel;
  In the liquid crystal display device, an optical axis center of the liquid crystal display panel and an optical axis center position of the positive lens can be varied.
  A liquid crystal display device of a technique related to the present invention includes a light emitting element,
  A liquid crystal display panel that modulates light emitted by the light emitting element;
  A magnifying lens for enlarging a display image of the liquid crystal display panel;
  A positive lens disposed between the light emitting element and the liquid crystal display panel;
  In the liquid crystal display device, at least one of the distance between the light emitting element and the positive lens and the distance between the liquid crystal display panel and the magnifying lens can be varied.
  A liquid crystal display device according to a technique related to the present invention includes a first light collecting unit that collects external light,
  A second light collecting means for collecting light emitted from the light emitting element;
  A measuring means for measuring the intensity of outside light;
  A liquid crystal display panel;
  Optical means for guiding light from at least one of the first light collecting means and the second light collecting means to the liquid crystal display panel;
  The liquid crystal display device is characterized in that on / off of the light emitting element or emission intensity is controlled according to a measurement result of the measuring means.
  A first aspect of the present invention is a liquid crystal display panel;
  Generates white light to illuminate the liquid crystal display panelLeft eye light emitting element and right eyeAn illumination means having a light emitting element;
  In the liquid crystal display panelLeft eye image and right eye imageDisplay an imageSignal processing forSignal processing means;
  SaidLeft eye light emitting device and right eye light emitting deviceIllumination control means for controlling on / off of the light emitting element,
  The signal processing means includesThe left-eye image is displayed on the liquid crystal display panel, and the left-eye image is displayed. Signal processing for displaying a black image after displaying an image, and displaying the right-eye image on the liquid crystal display panel, displaying the right-eye image, and then displaying the black image Alternately with the signal processing of
  The illumination control means includesIllumination control for turning on and off the left-eye light emitting element in synchronization with the display of the left-eye image, and turning on and off the right-eye light emitting element in synchronization with the display of the right-eye image Repeats lighting control alternatelyThis is a liquid crystal display device.
  BookA viewfinder of a technique related to the invention is a viewfinder including the above-described liquid crystal display device.
  The viewfinder of the technology related to the present invention includes a first light emitting element,
  A second light emitting element;
  A first liquid crystal display panel that modulates light emitted by the first light emitting element;
  A second liquid crystal display panel that modulates light emitted by the second light emitting element;
  A viewfinder comprising optical path synthesis means for synthesizing light modulated by the first liquid crystal display panel and the second liquid crystal display panel into one optical path.
  A camera of a technique related to the present invention includes a viewfinder having a light emitting element and a liquid crystal display panel that modulates light emitted from the light emitting element,
  A housing having a CCD element;
  A switch disposed on the viewfinder or the housing,
  The camera is configured such that the light emitting element is turned on by moving a position of the viewfinder disposed in the housing.
  The driving method of the light emitting element of the technology related to the present invention is a driving method of a lamp in which a filament for emitting thermoelectrons and an anode are coated with a phosphor film on the inner surface of a case.
[0015]
  Of the technology related to the present inventionIn the driving method, a voltage higher than the discharge start voltage is applied to the anode via a variable resistor to light the lamp, and after lighting, the voltage is lowered and the resistance value of the variable resistor is decreased. The current flowing through the anode is kept constant by reducing the voltage and the resistance value. Alternatively, a first voltage equal to or higher than the discharge start voltage is applied through the first resistor, and after lighting, the second voltage lower than the first voltage is lowered to the anode by the switch to the second resistor. If the resistance value of the second resistor is smaller than the resistance value of the first resistor, the current value that flows to the anode by the first voltage after lighting and the current value that flows to the anode when switched to the second voltage after lighting. Can be made substantially the same.
[0016]
  Of the technology related to the present inventionIn the driving method, in a state where a third voltage equal to or lower than the discharge start voltage is applied to the anode, a pulse signal is superimposed on the anode, and the lamp is turned on at a voltage equal to or higher than the discharge start voltage.
[0017]
Also,Of the technology related to the present inventionThe driving method is a method in which a current is supplied to the filament, a voltage is applied to the anode to light the lamp, and then the supply of current to the filament is interrupted. The filament is heated by increasing the current passed through the anode above a predetermined value. Thermal electrons are emitted from the filament by the heating, and the lamp is kept on even when the current to the filament is stopped.
[0018]
  Of the technology related to the present inventionThe viewfinder uses a lamp having a filament and an anode as light generation means, and condensing means (condensing lens, concave mirror, etc.) for converting white light from the lamp into parallel light, and emission from the condensing means. A liquid crystal display panel that modulates the emitted light. The anode of the lamp is planar, and the arrangement direction of the filament and the anode is orthogonal as shown in FIG. 2 (b). A direct current is allowed to flow through the anode of the lamp. Preferably, a reflective film or the like is formed on an inner surface or an outer surface of the lamp case and a portion where the light collecting means does not collect light. The reflection film or the like has a function of reflecting light emitted from the inside of the lamp case to the outside again.
[0019]
When the filament and the anode are orthogonal, the light output intensity is maximized in the direction of an angle of 45 degrees. Therefore, an angle of 45 degrees is directed toward the liquid crystal display panel.
[0020]
on the other hand,Of the technology related to the present inventionThe lamp used for the viewfinder is lit with direct current and the voltage applied to the anode is as low as 20 (V) or less, so it is easily affected by static electricity and may not light even when a voltage is applied to the anode. Therefore, a transparent conductor film such as ITO is applied to the outer surface of the lamp, and a conductive wire or the like is applied.
[0021]
Further, since mercury in the lamp is vaporized to emit mercury molecules, it is necessary to increase the mercury vapor temperature in the case in order to obtain a certain luminance or higher. Conversely, when the outside air temperature is lowered, the rise time of the light emission luminance of the lamp becomes longer.As a countermeasureThe temperature of the lamp at the start of lighting is detected by a temperature sensor such as a thermistor, and the current value flowing through the anode at the time of lighting is increased. Alternatively, the lamp brightness is measured after lighting, and the amount of anode current is fed back.
[0022]
  Of the technology related to the present inventionIn the viewfinder, an illumination optical system is composed of a lamp and a parabolic mirror to illuminate the liquid crystal display panel. More preferably, a spherical mirror is disposed on the entire surface of the parabolic mirror. A parabolic mirror is disposed, and the parabolic mirror condenses light emitted from the lamp and illuminates the liquid crystal display panel as parallel light. A light diffusion film is disposed between the lamp and the liquid crystal display panel. The reflecting surface of the parabolic mirror is embossed or made up of a plurality of micromirrors. A ring made of a resin (or glass or the like) that suppresses heat transfer is arranged at a location where the lamp and the parabolic mirror are close to each other, or is configured so as to avoid contact with a slight gap. The lamp is covered with a rubber cap attached with a diffusing agent such as Ti.
[0023]
  Of the technology related to the present inventionThe viewfinder includes a lamp, an illumination lens that illuminates the liquid crystal display panel by condensing light emitted from the lamp into parallel light, and an auxiliary lens disposed on the light output surface of the liquid crystal display panel. is there. Preferably, a reflector is disposed on the rear surface of the lamp so that more light is illuminated on the liquid crystal display panel side. The liquid crystal display panel is sandwiched between the illumination lens and the auxiliary lens so as to be perpendicular to the display surface of the principal ray liquid crystal display panel passing through the liquid crystal display panel. Preferably, the reflector is integrally formed on the rear surface of the resin, and a hole is formed in the resin, and the lamp is inserted. At this time, the hole is made slightly larger than the diameter of the lamp, and when the lamp is inserted and fixed, a small space is maintained between the resin hole and the lamp. In addition, an illumination lens or an auxiliary lens is attached to the liquid crystal display panel.
[0024]
  Of the technology related to the present inventionIn the viewfinder, the illumination optical system of the liquid crystal display panel is composed of a lamp and a Fresnel lens. Further, a diffusion sheet or the like is disposed between the Fresnel lens and the liquid crystal display panel. Preferably, the degree of diffusion of the diffusion sheet is a ratio at which a groove of a Fresnel lens can be seen when a viewer observes a display image on a liquid crystal display panel. MTF (Moderation Transmission Function) is set to 20% or less. In addition, the polarizer is attached to the flat portion of the Fresnel lens, and the Fresnel lens can be rotated around the lens center.
[0025]
  Of the technology related to the present inventionThe viewfinder is configured so that at least one of the distance between the lamp and the condenser lens and the distance between the condenser lens and the liquid crystal display panel can be expanded or contracted. When the viewfinder is not in use, the viewfinder is contracted to shorten the entire length of the viewfinder. When the viewfinder is used, the viewfinder is expanded, and the light emission position of the lamp is arranged exactly at the focal position of the condenser lens.
[0026]
  Of the technology related to the present inventionThe viewfinder includes a condenser lens that introduces external light (sunlight or the like) into the viewfinder. Preferably, the condenser lens is composed of a Fresnel lens, and a light amount adjusting polarizing plate for adjusting the intensity of external light entering the viewfinder is preferably disposed. Usually, the polarizing axis of the polarizing plate and the polarizing axis of the polarizer of the TN liquid crystal display panel are substantially matched, and when the external light is strong, the adjustment is performed by rotating the light amount adjusting polarizing plate.
[0027]
  Of the technology related to the present inventionThe viewfinder is a magnifying lens made of a flexible transparent resin. In the lens made of transparent resin, the central portion is thickened by pressing the peripheral portion, and the focal length is shortened. When the pressure is removed, the central portion becomes thinner, the positive power becomes smaller, and the focal length becomes longer.
[0028]
  Of the technology related to the present inventionThe viewfinder is configured so that the optical axis at the center of the condenser lens and the central axis of the lamp can be varied. Preferably, the condenser lens is composed of a Fresnel lens, and a diffusion sheet is disposed on the light exit surface of the Fresnel lens.
[0029]
  Of the technology related to the present inventionThe viewfinder mainly uses two or more of the above-described viewfinders, and optical images formed by two or more display panels are put into one optical path by a dichroic prism, a dichroic mirror, a half mirror, a polarizing beam splitter (PBS), or the like. It is synthesized.
[0030]
  Of the technology related to the present inventionThe viewfinder is an image that separates the lamp, the light converging means that collimates the light emitted from the lamp, the liquid crystal display panel, the light that reaches the left eye of the observer, and the light that reaches the right eye. And a splitter. Preferably, one lamp is disposed for each of the right eye and the left eye.
[0031]
  Of the technology related to the present inventionVideo cameras are mainlyOf the technology related to the present inventionA viewfinder is provided, and the viewfinder is attached to the video camera at a predetermined location and can be used at a different position. In addition, a push switch is provided on the main body of the video camera or the viewfinder and connected to the terminal of the lamp filament. Since the viewfinder is used, when the viewfinder is moved, the push switch is turned on and current flows through the filament to preheat the lamp.
[0032]
In addition,Of the technology related to the present inventionA viewfinder or a twisted nematic (TM) liquid crystal display panel, a polymer-dispersed liquid crystal display panel, or the like is used as the light modulation means of the display device. When a polymer dispersed liquid crystal is used, the thickness of the liquid crystal layer of the pixel that modulates red light is made larger than the thickness of the liquid crystal layer that modulates blue light. Or, in addition, the average particle diameter of the liquid crystal droplets of the water droplet-like liquid crystal or the average pore diameter of the polymer network is made larger for the pixel that modulates red light.
[0033]
  Of the technology related to the present inventionThe light emitting element is a constant current element. That is, when the lamp is lit, the voltage between the anode electrode and the ground potential becomes a constant value without depending on the current flowing through the anode. This voltage having a constant value is referred to as a discharge sustaining voltage in the sense of sustaining the discharge. However, even if it is a little lower than this value, it does not suddenly turn off.
[0034]
On the other hand, a voltage higher than the discharge sustaining voltage is required to start discharge. It is about 5 (V) higher than the normal discharge sustaining voltage. A voltage for starting this discharge (light emission) is called a discharge start voltage. A current limiting resistor is interposed between the anode electrode and the anode terminal to which the voltage is applied. When a discharge start voltage is applied to the anode terminal, a discharge start voltage is applied to the anode electrode, and discharge is started. Then, the potential of the anode electrode becomes a discharge sustaining voltage.
[0035]
That is, when the lamp is turned on, a discharge sustaining voltage may be applied to the anode electrode. The higher the voltage applied to the anode terminal, the greater the power lost in the current limiting resistor. This is the same even if the current limiting resistor is a constant current circuit.
[0036]
  Of the technology related to the present inventionThe lamp is driven by applying a voltage equal to or higher than the discharge start voltage to the anode via a resistance element, lighting the lamp, and allowing a steady current to flow through the anode. Thereafter, the voltage applied to the anode terminal is lowered while lowering the resistance value of the resistance element while maintaining the value of the steady current. By controlling as follows, the resistance value of the resistance element ultimately becomes 0, and the voltage applied to the anode terminal can be the discharge sustain voltage. Therefore, low power consumption can be achieved.
[0037]
  Of the technology related to the present inventionThe lamp is a constant current element, and starts lighting when a discharge start voltage is applied to the anode for a time of about 10 μsec.Of the technology related to the present inventionIn the driving method, a discharge sustain voltage is applied to the anode terminal in advance, and a voltage equal to or higher than the pulsed discharge start voltage is applied to the anode terminal for a time of about 10 μsec. The lamp is lit by the pulse voltage, and when lit, the voltage at the anode terminal becomes the discharge sustaining voltage. Therefore, the generation of the lamp can be maintained with low power.
[0038]
  Of the technology related to the present inventionThe driving method is to cut off the filament current after the lamp is turned on. In the hot cathode type lamp, the filament is heated, and thermal electrons are emitted from the filament by heating. The thermoelectrons are heated by the potential of the anode, collide with mercury molecules and generate ultraviolet rays. Ultraviolet rays are applied to the phosphor, and the ultraviolet rays are converted into visible light, and white light is emitted from the lamp. In other words, the filament needs to be heated in order for the lamp to be generated. However, if the current flowing into the anode is increased to a predetermined value or more, a part of the current acts on the filament and the filament is heated. Alternatively, electrons are extracted from the filament by the potential of the anode electrode. Therefore, light emission continues even when the filament current is interrupted.
[0039]
A DC positive voltage is applied to the anode electrode of the lamp, and a DC voltage (one terminal is grounded and the other terminal is positive) is applied to the filament. Thermoelectrons from the filament are attracted to the anode electrode. Accordingly, the larger the potential difference between the filament and the anode electrode, the faster the thermoelectrons, the greater the collision with mercury molecules, and the greater the amount of ultraviolet radiation.
[0040]
  Of the technology related to the present inventionThe viewfinder makes the filament and the anode electrode orthogonal. Then, assuming that a positive (+) potential is applied to the anode electrode and a ground potential is applied to the filament, the emission luminance is highest in the direction of just 45 degrees with respect to the filament formation direction. Therefore, the direction of 45 degrees where the luminance is highest is directed toward the liquid crystal display panel.
[0041]
  Of the technology related to the present inventionThe viewfinder illuminates the liquid crystal display panel by condensing light from a small lamp by condensing means. Since the light emitting area of the lamp can be reduced, low power consumption can be realized. The parabolic curve has a geometric property that makes light emitted from the focal point parallel light.Of the technology related to the present inventionIn the viewfinder, the light emitting area of the lamp is arranged at the focal point of the parabolic mirror, and the liquid crystal display panel is illuminated by making the light emitted from the lamp parallel light by the parabolic mirror. The observer sees the display image of the liquid crystal display panel from the eye cap, and when the lamp is close to the liquid crystal display panel, the lamp image may be seen. Therefore, as a countermeasure, a light diffusion (scattering) sheet is disposed between the liquid crystal display panel and the lamp.
[0042]
The TN liquid crystal display panel can realize a good contrast when vertical parallel light is incident. In the viewfinder, the diameter of the eyepiece that the observer looks into is small. This is to make the viewfinder smaller. Since the eyepiece lens is small, the principal ray emitted from the liquid crystal display panel needs to be narrowed (squeezed) toward the eyepiece lens. Accordingly, only the light radiated from the lamp (or the surface light source) passes through the liquid crystal display panel smoothly, and the display contrast of the liquid crystal display panel is lowered.
[0043]
  Of the technology related to the present inventionIn the viewfinder, an auxiliary lens is placed in front of the liquid crystal display panel. The light emitted from the lamp is collimated by the illumination lens, and the parallel light passes through the liquid crystal display panel and passes through the liquid crystal display panel toward the eyepiece. Squeeze the rays. That is, the light incident on the liquid crystal display panel is telecentric. For this reason, light parallel to the normal line of the display surface of the liquid crystal display panel can be incident, and a good display contrast can be obtained. If the auxiliary lens or the like is attached to the liquid crystal display panel, dust does not adhere to the display surface of the liquid crystal display panel.
[0044]
Overall length of just viewfinder for the illumination lens has a constant thickness using a convex lens made of plastic or glass is long.Of the technology related to the present inventionIn the viewfinder, the illumination lens is a Fresnel lens. Since the Fresnel lens is a 1-2 mm plate, the overall length can be shortened. However, when an observer views the display image on the liquid crystal display panel, a Fresnel lens groove may be seen. As a countermeasure, a light diffusion sheet is disposed between the Fresnel lens and the liquid crystal display panel.
[0045]
furtherOf the technology related to the present inventionThe viewfinder is configured so that any one of the illumination lens and the lamp, the illumination lens and the liquid crystal display panel, and the like can be contracted and expanded. Shrink the viewfinder when not in use. Therefore, it can be made compact. When using the viewfinder, extend it so that the lamp is at the focal point of the illumination lens. Also, the observer should focus on the display surface of the liquid crystal display panel.
[0046]
When the video camera is used outdoors, it is not necessary to illuminate the liquid crystal display panel with external light such as sunlight, and to illuminate the liquid crystal display panel with this external line. That is, power consumption can be reduced by turning off the lamp. Since sunlight has good parallelism, it can be condensed with a convex lens. This principle can be easily understood from the fact that sunlight can be focused with a magnifying glass and black paper in focus can be burned. The collected light can be restored to parallel light by using a convex lens.Of the technology related to the present inventionThe viewfinder captures sunlight into the viewfinder with a condensing lens, and converts the captured light into parallel light with an illumination lens. Sunlight becomes parallel light with good narrow directivity (sharp directivity, although there is some debate) with the illumination lens.
[0047]
  Of the technology related to the present inventionThe viewfinder is a magnifying lens made of a flexible resin. When the peripheral part of the resin lens, which is a resin lens, is held down, the central part swells and the focal length of the lens becomes short. Conversely, if the pressure at the periphery is reduced, the lens returns to its original shape and the focal length of the lens increases. In the conventional viewfinder, the observer adjusts the position of the eyepiece lens according to the visual acuity of his / her eye to adjust the focal length of the liquid crystal display panel. The magnifying (eyepiece) lens is attached to a holder, and is configured so that the holder position can be adjusted. Therefore, a movement space for adjusting the position of the holder is necessary, and the total length of the viewfinder is shortened.The present invention Related technologyIn the viewfinder, the magnifying lens is made of resin and does not need to be moved back and forth. Therefore, since a holder is not necessary, a movement space for position adjustment is unnecessary, so that the overall length of the viewfinder can be shortened.
[0048]
  Of the technology related to the present inventionThe viewfinder is configured so that the optical axis at the center of the condenser (illumination) lens and the central axis of the lamp can be varied. By changing the central optical axis of the condenser lens and the central axis of the lamp, the angle of the principal ray incident on the liquid crystal display panel can be changed.
[0049]
  Of the technology related to the present inventionThe viewfinder is a technique for combining display images of two or more liquid crystal display panels with a dichroic mirror or the like. By combining the display images, the number of pixels of the cover image viewed by the observer is the total number of pixels of the liquid crystal display panel × the number of used panels. Therefore, high-definition image display can be realized.
[0050]
  Of the technology related to the present inventionThe viewfinder allows light emitted from two light sources (lamps) to enter the liquid crystal display panel obliquely. The light from the first light source is configured to be mainly incident on the right eye of the observer, and the light from the second light source is configured to be mainly incident on the left eye of the observer. An image splitter is arranged between the liquid crystal display panel and the observer to distribute the light from the two light sources to the left and right eyes. Pixels on which an image for the left eye and an image for the right eye are displayed on the liquid crystal display panel, light from the first lamp is displayed on the image on which the image for the left eye is displayed, and an image on the right eye is displayed The light from the second lamp is made incident on. With the configuration described above, the observer can see a stereoscopic image.
[0051]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0052]
Figure 1Reference examples related to the present inventionIt is sectional drawing of a viewfinder. However, it is schematically drawn for easy explanation. In addition, there are parts that are partially enlarged or reduced, and some parts are omitted. The above also applies to other drawings.
[0053]
At one end of the viewfinder, a light source including a lamp 11, a parabolic mirror 12, and a base substrate 14 for mounting the parabolic mirror 12 is disposed. A diffusion (scattering) sheet 15 or a diffusion plate is disposed between the lamp 11 and the liquid crystal display panel 1333. Either a diffusion plate or a diffusion sheet may be used, but here, the diffusion sheet 15 will be described. The diffusion sheet 15 has a function of preventing the image of the lamp 11 from being seen when an observer (not shown) looks at the display image on the liquid crystal display panel 1333 via the magnifying (eyepiece) lens 1336. The light scattering characteristics of the diffusion sheet 15 may be low. This is simply to make the image of the lamp 11 difficult to see. On the other hand, if the degree of scattering is high, the directivity of the light emitted from the lamp 11 becomes too wide, and the light utilization efficiency from the lamp 11 is deteriorated. As an example of the diffusion sheet 15, there is Kimoto's product number light-up series 100MX, 100SX, 100SH or 100S. In addition, a diffuser plate made by Plastics Co., Ltd. can be used. The surface 43 (embossed surface) 43 faces the liquid crystal display panel 1333 as shown in FIG. Further, an antireflection film is formed on the opposite surface. If it is not arranged in this way, the light transmittance of the diffusion sheet 15 becomes very poor. This configuration is important. In addition, a diffraction grating, a microlens array, a cell hook lens array, or the like can be used as the diffusion plate. That is, the diffusion plate or diffusion sheet 15 may be an optical low pass filter.
[0054]
In FIG. 2, the parabolic mirror 12 is attached to the lamp 11 with a buffer member 26 (a specific shape is exemplified by a donut shape). Examples of the material of the buffer member 26 include Teflon, polypropylene resin, silicone rubber, polyester resin, acrylic, polycarbonate, and the like. The heat from the lamp 11 is prevented from being transmitted to the parabolic mirror 15, and the lamp 11 Has a function to buffer the shock to the.
[0055]
A reflective film made of aluminum (Al) is formed on the reflective surface 22 on the inner surface of the parabolic mirror 12. The light emitting area of the lamp 11 is disposed at the focal point of the parabolic mirror 12. Therefore, the light emitted from the lamp 11 is converted into parallel light (narrow directivity light) by the parabolic mirror 12, passes through the diffusion sheet 15, and illuminates the liquid crystal display panel 1333. Although the reflecting surface 22 is formed or arranged on the inner surface of the parabolic mirror 12, the reflecting surface may be formed on the outer surface when the parabolic mirror 12 is formed of a transparent material. For example, a parabolic mirror is formed of acrylic resin, and a metal thin film made of aluminum is formed on the inner surface or outer surface thereof. Further, when the parabolic mirror 12 is formed of a metal object, it is not necessary to newly form the reflecting surface 22. This is because the parabolic mirror 12 made of metal can also serve as the reflecting surface 22. The parabolic mirror 12 may be formed by adding a titanium (Ti) powder to a polycarbonate resin. Titanium has the function of diffusing light. That is, a cloudy resin is used. In this case, it is not necessary to form the reflecting surface 22. Although the directivity of the light emitted from the lamp 11 is poor, it is practically acceptable. An example of the characteristics of the parabolic mirror 12 is shown in FIG. The effective diameter of the parabolic mirror 12 is made larger than the diagonal length of the display area of the liquid crystal display panel 1333. This is for illuminating the liquid crystal display panel satisfactorily.
[0056]
Further, the inner surface of the parabolic mirror 12 may have a shape in which a plurality of minute mirrors are combined as shown in FIG. 3A or an embossed shape as shown in FIG. With the configuration as shown in FIG. 3, uneven light emission due to the luminance distribution of the lamp 11 becomes difficult to see, and the liquid crystal display panel 1333 can be illuminated uniformly. This is particularly effective when the lamp 11 is a hot cathode system. This is because the lamp 11 has a large luminance distribution on the light emitting surface.
[0057]
As shown in FIG. 2, the parabolic mirror 12 is directly attached and fixed to the socket 27 of the lamp 11 by a projection 30a. The socket 27 is fixed to the base substrate 14 with a protrusion 30b.
[0058]
The front end of the lamp 11 and the diffusion sheet 15 are spaced apart from each other. This is because the heat of the lamp 11 is conducted to the diffusion sheet 15 and the diffusion sheet 15 is not deteriorated. Specifically, the distance is about 0.5 mm to 2 mm. However, if the diffusion sheet 15 is plate-shaped and has good heat resistance, a recess may be formed at the center of the diffusion plate 15a and the tip of the lamp 11 may be inserted as shown in FIG. With this configuration, the lamp 11 can be aligned with the recess of the socket 27 and the diffusion plate 15a and is fixed, so that it is not displaced due to impact or the like.
[0059]
Since the light emitted from the light emitting area of the lamp 11 cannot illuminate the liquid crystal display panel 1333 by the parabolic mirror 12, the light reflecting cylinder 32 is placed on the lamp 11 as shown in FIG. The light reflecting cylinder 32 reflects the light emitted from the lamp 11 on its inner surface, returns to the inner surface of the lamp 11 again, and is emitted from an effective light emitting region. Furthermore, forming or disposing a reflective film on the bottom surface of the lamp 11 is directly connected to effective use of light. Thereby, the luminance rise characteristic and the starting characteristic of the lamp 11 are also improved.
[0060]
The lamp 11 has three terminals 16. One is an anode terminal 16 c that applies a voltage to the anode electrode 25, and the other two are filament terminals 16 a and 16 b that supply current to the filament 24. Each terminal 16 passes through the socket 27 and is connected to the terminal 28. The terminal 28 is connected to the wiring of the base substrate 14 by solder 29. Components 17 (17a, 17b) of the drive circuit of the lamp 11 are mounted on the base substrate 14.
[0061]
Next, the lamp 11 will be described. The lamp case 21 of the lamp 11 is made of glass, and is usually formed by processing a glass tube having a thickness of 0.21 to 0.5 mm. A filament 24 for emitting thermoelectrons and an anode electrode 25 for applying an electric field to the emitted thermoelectrons are disposed inside.
[0062]
The filament 24 includes carbonates of barium, strontium and calcium (BaCO_Three, SrCO_Three, CaCO_Three) And heated in a vacuum to oxidize and activate an oxide. A phosphor made of rare earth is applied to the inner surface of the lamp case 21. In particular, a three-wavelength type phosphor is desirable. This is because the light use efficiency is improved by matching with the light transmittance of the color filter of the liquid crystal display panel. The color temperature of the emitted light is preferably 6000 K or more and 9000 K or less. If the color temperature is 6000 K or higher, the image quality will be satisfactory. The higher the color temperature, the better the display quality, but the lower the display brightness of the lamp.
[0063]
The diameter of the lamp 11 is preferably 5 mm or less. This is because the volume of the lamp 11 is reduced, the luminance rise characteristic is accelerated, and the emission luminance is also increased. However, if the thickness is 2 mm or less, it is difficult to dispose the anode electrode 25 inside the lamp 11, and the discharge start voltage also increases.
[0064]
The anode electrode 25 has a ring shape and applies an electric field to thermal electrons. Further, during manufacture, mercury is penetrated or applied to the ring, and after the anode electrode 25 is disposed on the lamp case 21, it is also used to generate mercury vapor in the lamp case 21 by irradiation with microwaves.
[0065]
The lamp case 21 is sealed with argon gas, krypton gas, neon gas and the like together with mercury vapor. Xenon gas can also be used. Xenon gas is preferable because of its low temperature dependency. However, xenon gas alone makes the startability worse. Therefore, it is preferable to mix a small amount of neon gas with xenon gas. The luminous efficiency is high when the argon gas is 98% or more. However, the luminance change with respect to temperature is slightly large.
[0066]
The anode electrode 25 has a planar shape as shown in FIGS. Examples of the shape of the anode electrode 25 include a doughnut shape of (c), a plate shape of (d), or a shape in which a hole (a bulge or a recess may be formed) is formed in the center of (e). The The planar shape of the anode electrode 25 means that the anode electrode 25 is not a cube, and it corresponds to a planar shape as shown in FIGS.
[0067]
A direct current (DC) voltage in the range of 2.0 (V) to 6.0 (V) is applied to the two terminals (16a, 16b) of the filament 24. The voltage applied to the filament 24 is preferably in the range of 2.5 to 4.5 (V). Within this range, the generated luminance of the lamp 11 is high even if the input power is the same. This is because the surface area of the filament 24 is increased. The filament 24 is heated by the applied voltage, and thermoelectrons are emitted from the oxide on the surface of the filament 24. A direct current (DC) voltage of 9 (V) or more is applied to the terminal 16 c of the anode electrode 25. The voltage applied to the anode electrode 25 is a direct current, but the voltage applied to the filament 24 may be an alternating current.
[0068]
The electrons emitted from the filament 24 are accelerated by the voltage applied to the anode electrode 25, and the thermal electrons collide with mercury molecules. Ultraviolet rays are generated by this collision, and the ultraviolet rays are irradiated to the phosphor 23 to generate visible light.
[0069]
Anode voltage V during discharge (light emission)_a(Hereinafter referred to as discharge sustaining voltage) is 9.5 (V) to 11.5 (V). However, in order to start discharge (light emission), a voltage of 15.0 (V) or higher (hereinafter referred to as a discharge start voltage) is required. The discharge start voltage increases as the diameter of the lamp 11 decreases.
[0070]
In the lamp case 21, ultraviolet rays are generated due to collisions between thermoelectrons and mercury molecules. The generated ultraviolet light is 254 nm. However, some ultraviolet rays having a wavelength of 185 nm are also generated. It is not preferable to use 185 nm ultraviolet rays because the energy of the 185 nm ultraviolet ray is large, and the phosphor used is a barium / magnesium-based phosphor, since the blue phosphor is particularly damaged and the color temperature changes. One end of the lamp 11 is sealed with a bead-shaped sealing member 20.
[0071]
A reflective film (reflective surface 22) made of aluminum (Al) may be formed inside the lamp case 21. The reflective film reflects the ultraviolet rays in the case 21, and the reflected ultraviolet rays are applied to the phosphor 23 on the front surface. Therefore, the light emission luminance of the effective light emission region is increased. As described above, the light utilization efficiency can be improved by forming a film that reflects ultraviolet rays on the inner surface.
[0072]
FIG. 2B is a sectional view of the lamp 11. The anode electrode 25 and the filament 24 are disposed substantially orthogonal to each other. That is, it is orthogonal to the longitudinal direction of the flat portion of the anode electrode 25 and the filament 24.
[0073]
In FIG. 2, 12 is a parabolic mirror, but is not limited thereto. For example, as shown in FIG. 5A, a combination of a parabolic mirror and a spherical sphere may be used. In FIG. 5, the light 51 a emitted from the lamp 11 is reflected by the reflecting surface 22 (b region in the figure) of the parabolic mirror 11 to be substantially parallel light, and illuminates the liquid crystal display panel 1333. If there is no spherical mirror (region a in the figure), the light beam 51c emitted from the lamp 11 is never used twice. However, when the generation region of the generation lamp 11 is positioned at the focal point of the spherical mirror, the light beam 51c is reflected by the region a of the reflection surface 22 to be reflected light 51b, and is again illuminated and scattered by the phosphor 23 of the lamp 11, and the light. Part of the light becomes 51d and illuminates the liquid crystal display panel 1333. From the above, the light emission luminance of the lamp 11 can be improved by the spherical mirror, and the light utilization efficiency can be improved.
[0074]
In addition, it is preferable to arrange | position the formation part of a spherical mirror in the location shown as an oblique line, as shown in FIG.5 (b). In other words, the effective display area (image display section) of the liquid crystal display panel 1333 is irradiated with parallel light by the parabolic mirror 12, and light emitted from the lamp 11 to the other area (shaded area) is applied to the lamp 11 by the spherical mirror. It will return.
[0075]
Note that the paraboloidal mirror, the spherical mirror, and the like do not mean a perfect paraboloid or a spherical surface, respectively, but may be aspherical. By experimenting, the concave mirror is designed to collect light better.
[0076]
Although the liquid crystal display panel 1333 is irradiated with substantially parallel light, the substantially parallel light means light that is necessary for the observer to see the display image on the liquid crystal display panel 1333 well, and is strictly parallel light. It is not a thing. For example, in the periphery of the display area of the liquid crystal display panel 1333, the chief rays are optically large when not vertical, and in order to secure sufficient directivity, the state of parallel light is considerably poor and the light spreads. The solid angle may be large. All of these are collectively referred to as substantially parallel light for convenience.
[0077]
In FIG. 6, the light exit surface of the parabolic mirror 12 is bent and the reflection mirror 22a is arranged. The light 51 a emitted from the lamp 11 is reflected by the mirror 22 a and reflected by the mirror 22 b of the parabolic mirror 12 to illuminate the liquid crystal display panel 1333. Of course, the light 51b emitted from the tip of the lamp 11 directly illuminates the liquid crystal display panel 1333, and the light 51c is reflected once by the reflection surface 22b of the parabolic mirror 12 to illuminate the liquid crystal display panel 1333.
[0078]
At this time, in FIG. 7A, when the lamp 11 side is viewed from the diffusion sheet 15, a low brightness portion 71 may be generated on the outer peripheral portion of the lamp 11. This is because the buffer member 26 does not reflect light, so that the amount of light incident on the low luminance portion 71 is small. In order to solve this, there is a method of covering the rubber cap 72 as shown in FIG. A diffusing agent such as Ti is added to the rubber cap 72 to form a scatterer. By this rubber cap 72, the entire rubber cap 72 shines, and the low luminance portion shown in FIG.
[0079]
In addition to the rubber cap 72, silicon resin, polycarbonate, acrylic resin, epoxy resin, ground glass, or the like can be used. The rubber cap 72 and the lamp 11 preferably have a small space. This configuration is shown in FIG. A space is held by the protrusion 73. The space has an effect of keeping the lamp 11 warm. This is because air has poor thermal conductivity. Due to this heat retention effect, the light emission luminance of the lamp 11 at a low temperature becomes good.
[0080]
There is also a method in which the lamp 11 is formed into a spherical shape as shown in FIG. 8 without covering the rubber cap 72. Since the portion coated with the phosphor 23 becomes a light emitting surface, the low luminance portion 71 does not occur even if the buffer 26 is present.
[0081]
The light emission luminance of the lamp 11 increases as the energy enclosed in the lamp case 21 increases. Theoretically (ideally), the emission luminance is inversely proportional to the square of the inner diameter of the lamp. Therefore, in order to increase the light emission luminance, a shape in which the tip of the lamp is thinner than the root as shown in FIG. 9 is preferable. In addition, it is preferable to form the reflective films 91a and 91b in places that cannot be used.
[0082]
As shown in FIG. 9, it is effective to form or arrange a light-reflective metal thin film on the bottom surface of the lamp 11 and preferably on the side surface of the lamp 11. Examples of the metal thin film include an aluminum foil, a copper sheet, and an aluminum deposited film. The metal thin film (which is conductive and has light reflectivity. For example, a carbon thin film may be applied) is grounded to a fixed potential such as a ground terminal of the filament 24. With this configuration, the startability of the lamp 11 is improved. This is presumably because the energy density is increased by reflecting the light generated by the lamp 11 with the conductive thin film.
[0083]
As another method for improving the luminance, there is a configuration shown in FIG. FIG. 10A shows a lamp 11 covered with a condensing cap 101 having a concave exit surface, and FIG. 10B shows a prism-like one (condensing prism 102) attached with an adhesive 103. is there. By comprising in this way, the light quantity which can be irradiated to a front can be increased. Of course, as shown in FIG. 10 (c), the lamp 11 is covered with a reflecting tube 105 made of metal or the like, and the tip (front) portion is covered with a diffusion plate 106. By filling the transparent resin 104 between the reflecting tube 105 and the lamp 11, the entire area of the diffusion plate 106 has uniform brightness. It is also effective to cover the lamp 11 with a metal case (reflection cap 107) as shown in FIG.
[0084]
The lamp 11 is lit with a DC voltage and continues to emit light. Also, the voltage applied to the anode electrode 25 is relatively small, 20 (V) or less. For this reason, even when a voltage is applied to the electrostatically charged lamp 11, the lamp 11 may not be lit. In particular, if an attempt is made to turn on the lamp immediately after touching the surface of the lamp 11, it may not turn on for a while. This is because human static electricity may be charged to the interface of the phosphor film 23 or the like. However, there is no practical problem because the lamp 11 is not directly touched by the hand in the normal viewfinder.
[0085]
As a measure against antistatic, there is a method of applying a transparent conductor film such as ITO on the outer surface of the lamp case 21 as shown in FIG. The ITO film 111 is grounded. There is also a method in which a conductive paste is applied lightly instead of the ITO film. There is also a method of applying carbon. In addition, there is a method of forming an antistatic film 112 as shown in FIG. Also, as shown in FIG. 12, a method of winding a lead wire (enamel wire, carbon wire, etc.) around the outer periphery of the lamp 11 is also effective. It is also effective to arrange a wire mesh or the like on the outer periphery of the lamp 11 as shown in FIG. By taking the above measures, the lamp 11 can be reliably lit without being charged.
[0086]
By using nichrome wire as the conducting wire, the lamp 11 can be heated to improve the starting characteristics. For example, as shown in FIG. 43, a current is applied to the conducting wire when the switch 423 is turned on. Steady light emission can be started satisfactorily immediately after the lamp 11 is heated by the application of current and a voltage is applied to the anode electrode 25. This is particularly effective when the ambient temperature is low. Effective as a countermeasure against static electricity.
[0087]
As shown in FIG. 14, a method of grounding the anode electrode 25 through a high resistance (about 1 MΩ) is also effective as a countermeasure. The potential of the anode electrode 25 is stabilized, and the charge is extremely reduced.
[0088]
In addition, as shown in FIG. 15, when the parabolic mirror 12 is made of a conductor such as a metal that also serves as the reflecting surface 22, a method of grounding the parabolic mirror 12 can provide good results. Of course, a large amount of charge is generated, and when the lamp 11 is charged, it does not light up. This is presumed to be because the electric field potential around the lamp 11 is stabilized.
[0089]
FIG. 44 shows a method of using the lamp 11 in a horizontal position. The present invention is not limited to this, and the lamp 11 may be used vertically as shown in FIG. 44A shows a lamp case 401 covered with a transparent case having a concave exit surface, and FIG. 45B shows a prism-like one attached with an adhesive 301. By comprising in this way, the light quantity which can be irradiated to a front can be increased. Of course, as shown in FIG. 45 (c), the lamp case 401 is covered with a reflecting tube 302 made of metal or the like, and the tip (front) portion is covered with a diffusion plate 293. By filling the transparent resin 291 between the reflecting tube 302 and the lamp case 401, the entire area of the diffusion plate 293 has uniform brightness. It is also effective to cover the lamp case 401 with a metal case 294 as shown in FIG.
[0090]
next,Reference examples related to the present inventionA driving method of the light emitting element will be described.Reference examples related to the present inventionTwo voltages (currents) are required for lighting the light emitting element. One is the filament voltage E_h It is. The filament voltage is 1.5 (V) to 6.0 (V), and when it is about 2 (V), the filament current flows about 40 (mA). The filament voltage should be relatively high. In particular, the same electric energy may be used in the range of 3.0 (V) to 5.0 (V). The other is the anode voltage E applied to the anode electrode 25._aIt is. Anode voltage E_aThe voltage for maintaining discharge (light emission) (discharge sustaining voltage Ec) and the voltage for starting discharge (light emission) (discharge start voltage E_s) The sustaining voltage Ec is a voltage between the anode electrode 25 and GND, and is 9 (V) to 12 (V). However, the voltage tends to increase as the diameter of the lamp 11 decreases and the internal gas pressure increases. Discharge start voltage E_sIs 15 (V) or more. Similarly, the voltage Es tends to increase as the diameter of the lamp 11 decreases and the internal gas pressure increases. Also, the anode current I at the rated time_aIs 3 (mA) to 10 (mA).
[0091]
A lower power supply voltage used for the lamp 11 is preferable because power consumed by the lamp 11 is reduced. Therefore, it is preferable that the voltage of the power source is effectively applied to the anode electrode 25 to maintain a predetermined light emission luminance. for that reason,In reference examples related to the present invention,As shown in FIG. 16, the lamp 11 is turned on and the light emission state is maintained as follows.
[0092]
First, the voltage E is applied to the filament 24 before the voltage is applied to the anode electrode 25._hIs applied and the filament 24 is heated. This is because if the voltage is applied to the anode electrode 25 without heating the filament 24, the role of reducing the oxide on the filament 24 is increased more than usual, and the life of the lamp 11 is shortened. A voltage should be applied to the anode electrode 25 after at least 0.1 second or more has passed since the current of the filament 24 is passed.
[0093]
Next, the discharge start voltage E from the variable power source 162_sAbove voltage E₁And a discharge start voltage E is applied to the variable resistor 163._sAbove voltage E₁Is applied to the anode electrode 25 at the rated current I_aIs set to the value that flows. Note that the variable resistor 163 may be used to mean a variable current element, and may be formed of, for example, an FET, a transistor, or the like. A thermistor or the like may also be used. Voltage E₁Is applied, the lamp 11 starts to emit light. However, in this state, the voltage drop generated by the variable resistor 163 is large and the power utilization rate is bad. Therefore, the timer circuit 161 changes the resistance value of the variable resistor 163 and changes the voltage output from the variable power source 162 during a predetermined period (for example, 1 second after the lamp 11 is turned on), thereby maintaining the anode discharge maintaining voltage E._cLower to about +0.5 (V).
[0094]
At this time, the current flowing through the variable resistor 163 is a predetermined value I._aTo maintain. Finally, the voltage drop at the variable resistor 163 is set to about 0.5 (V), and the anode sustain voltage E is applied to the anode electrode 25._cIs applied. The predetermined time is set by controlling the ON / OFF of the input switch SW of the timer circuit 161 by a microcomputer. The discharge sustaining voltage Ec changes until the light emission of the lamp 11 is stabilized. Therefore, the timer circuit 161 is operated after a sufficient time.
[0095]
As another driving method, as shown in FIG._sAbove voltage E₁And a sustaining voltage E_cAbove voltage E₂There is a method of lighting the lamp 11 by using two power sources that generate the light. Hereinafter, the driving method shown in FIG. 17 will be described.
[0096]
Current limiting resistor R₁Is power E₁Is applied to the anode electrode 25 when_aCurrent limiting resistor R₂Is the power supply E₂Is applied to the anode electrode 25 when_aIs to flow. First, the voltage E is applied to the filament 24._hIs applied, and a current flows through the filament 24. At this time, both analog switches 172a and 172b are preferably open. Next, analog switch SW₁Is turned on (or off), and the voltage E is applied to the anode electrode 25.₁Is applied. Therefore, the lamp 11 starts discharging (light emission). Next, the switch SW is closed by the microcomputer after a predetermined time, the logic output of the timer circuit 161 is inverted, and the analog switch SW₂After turning on, the analog switch SW is opened. Analog switch SW₂Is turned on, the voltage E is applied to the anode electrode 25.₂Is applied and the discharge state is maintained.
[0097]
16 and 17 show that the lamp 11 is turned on by applying a steady-state voltage to the anode electrode 25. However, FIG. This is applied to turn on the lamp 11. First, when the ON signal 2 is applied to the DCDC converter 201b, the filament voltage E from the voltage outlet terminal of the DCDC converter 201b._hIs output. Specifically, E_hIs around 2 to 3 (V). The current is a direct current of around 40 (mA). As the filament current flows through the filament 24, the oxide on the filament 24 is heated and thermoelectrons are emitted.
[0098]
Next, the ON signal 1 is also applied to the DCDC converter 201a, and the discharge sustain voltage E is applied from the voltage output terminal._aIs output. Discharge sustaining voltage E_aIs specifically 9 (V) to 13 (V). VR is a volume for adjusting the current flowing into the anode electrode 25 when the lamp 11 is discharged (light emission state). If the value of VR is increased, the current flowing into the anode electrode 25 is decreased, and the light emission luminance of the lamp 11 is decreased. If the value of VR is decreased, the current flowing into the anode electrode 25 is increased, and the light emission luminance of the lamp 11 is increased. The VR is also used to adjust the individual variation of the lamp 11. This is because if the disposition distance between the anode electrode 25 and the filament 24 is different, the lamp 11 has a brightness variation of about ± 20%.
[0099]
The VR value needs to be adjustable from about 50Ω to about 300Ω. C₁Is an electric field capacitor, Q₁Is an NPN transistor, Q₂Is a PNP transistor. Q when the output of the inverter 171 is L₂Turns on and capacitor C₁When the output of the inverter 171 is H, the b terminal of₁Turns on and capacitor C₁The b terminal has a voltage E_aIs applied. Electric field capacitor C₁Is determined by a time constant with the resistance value of VR. It is necessary to apply at least a voltage equal to or higher than the discharge start voltage to the anode electrode 2 for 2 μsec or longer. Preferably, it is necessary to apply for 10 μsec or more.
[0100]
The anode 25 has a sustaining voltage E_aIs first applied. Next, the output of the inverter 201 is first set to L level by a microcomputer or the like, and the capacitor C₁The b terminal is set to GND + 0.6 (V). At this time capacitor C₁A terminal is E_aA voltage is applied. Next, the output of the inverter 171 is set to H level. Then capacitor C₁The b terminal suddenly goes from GND + 0.6 (V) to E_aIt changes to -0.6 (V). Therefore, the capacitor C₁The a terminal of E is E_a+ (E_a-0.6) Changes to (V). If the voltage is applied for a period of 2 μs or more above the discharge start voltage, the lamp 11 is turned on. When lamp 11 is lit, capacitor C₁The charge that has been charged in the a terminal flows into the anode electrode 25, and the a terminal is (E_a-VR value (resistance value) x anode current).
[0101]
In order to turn off the lamp 11, the output of the inverter 171 is changed to L level in the lighting state. Then capacitor C₁Since the b terminal becomes GND + 0.6 (V), the a terminal also changes in the same manner, and the voltage of the anode electrode 25 becomes considerably lower than the discharge sustaining voltage, so that the lamp 11 is turned off. Capacitor C₁, Transistor Q₁, Q₂This configuration is for applying a pulse voltage higher than the discharge start voltage to the anode electrode 25, and it goes without saying that other configurations may be used. For example, an FET or the like can be used. The voltage applied to the anode electrode 25 may be a voltage equal to or higher than the discharge start voltage, and may be a pulse shape, a step shape, a distorted rectangle or a sine wave. Further, the voltage E is supplied from the battery 202 through the DCDC converter 201._a, E_hHowever, if the battery voltage is equal to or higher than the sustaining voltage, the output voltage from the battery 202 may be applied directly to the anode electrode 25.
[0102]
In order to adjust the light emission luminance of the lamp 11, there is a method of adjusting by applying a pulse voltage to the anode electrode 25 as shown in FIG. When light enters the photodiode 181 in the light detection circuit 183, the output voltage of the operational amplifier 182 increases. The output voltage of the photodiode 181 increases when the external light is strong. C and R of the photodetection circuit 183 are integration circuits for reducing noise in the output from the photodiode 181. The limited number of CR is 1/10 seconds or less.
[0103]
When the output voltage of the operational amplifier is high (external light is strong at this time, that is, when used outdoors), the light emission luminance of the lamp 11 is increased. Conversely, when the output voltage of the operational amplifier is low (at this time, the external light is weak, that is, when used indoors), the luminance of the lamp 11 may be low. When the voltage input to the oscillation circuit 184 is high, the oscillation state is in the state (2) (many parts are high in voltage). Conversely, when the voltage input is low, the oscillation state is in the state (1) (voltage). There are many low parts).
[0104]
It should be noted that as the voltage is higher, the time during which the voltage is applied to the anode electrode 25 becomes longer, and high luminance display is performed in terms of effective value. The output of the oscillation circuit 184 is input to the amplifier 185, and the output of the amplifier 185 outputs a rectangular wave having a voltage E equal to or higher than the GND voltage and the discharge start voltage. The longer the period of the voltage E equal to or higher than the discharge start voltage, the higher the brightness of the lamp 11 is lit. Resistance R_aIs a current limiting resistor.
[0105]
In FIG. 16, while the resistance value of the variable resistor 163 changes, SW in FIG.₁, SW₂Until the lamp is switched, the pulsed voltage in FIG. 19 is applied, and the light emission luminance of the lamp 11 may change until the lamp is lit stably. During this time, if the observer sees the display image on the display panel 1333, the viewer feels uncomfortable.Reference examples related to the present inventionThe viewfinder solves this countermeasure as shown in FIG. 19 below.
[0106]
First, the drive circuit of the liquid crystal display panel 1333 will be described. 191 is a video amplifier that amplifies the video signal to a predetermined value, 192 is a phase dividing circuit that creates positive and negative video signals, 193 is an output switching circuit that outputs an AC video signal whose polarity is inverted for each field, and 194 This is a drive circuit controller for synchronizing and controlling the source drive circuit 195 and the gate drive circuit 196.
[0107]
First, the gain of the video signal is adjusted by the video amplifier 191 so that the video output amplitude corresponds to the electro-optical characteristics of the liquid crystal. Next, the gain-adjusted video signal enters the phase dividing circuit 192, and two video signals of positive polarity and negative polarity are produced. These two video signals enter the output switching circuit 193, and a video signal having the polarity inverted every field or one horizontal scanning period is output. The reason for inverting the polarity of the signal for each field is to prevent the liquid crystal from being deteriorated by applying an AC voltage.
[0108]
Next, the video signal from the output switching circuit 193 is input to the source drive circuit 195, and the source drive circuit 195 performs signal processing such as level shift and sample hold of the video signal according to the control signal from the drive circuit control unit 194. In synchronization with the gate drive circuit 196, a predetermined voltage is output to the source signal line of the liquid crystal display panel 1333.
[0109]
When an on voltage is applied to the gate signal line, the TFT connected to the gate signal line is turned on, and the video signal output to the source signal line is applied to the pixel electrode. When the off voltage is applied to the gate signal line, the TFT is turned off, and the signal applied to the pixel voltage is held for one field.
[0110]
Taking FIG. 16 as an example, the variable power source 162 is connected to the discharge sustaining voltage E before the lamp is turned on._c(Until +0.5 (V)), the switch SW1 is connected to the ground (for example, the potential of the counter electrode 243 of the liquid crystal display panel 1333) (b terminal position). Next, in the second stage (after the variable power supply 162 outputs the discharge sustaining voltage Ec + 0.5 (V)), the switch SW1 is switched to the a terminal, the video signal is applied to the amplifier 191, and the image is displayed on the liquid crystal display panel 1333. Is displayed.
[0111]
When the switch SW1 is the b terminal, no image is displayed on the liquid crystal display panel 1333 (the display is controlled so as to display black). Even if the luminance of the lamp 11 changes during black display, the observer hardly recognizes the change. The black display described above means a non-video display state, and is a concept including display states such as raster display and dark display in addition to black display.
[0112]
In the viewfinder of FIG. 1, the observer moves the magnifying lens 1336 back and forth to adjust the position so that the virtual image of the display image on the liquid crystal display panel 1333 looks good. Therefore, the magnifying lens 1336 is attached to the attachment holder 1335. That is, focus adjustment is performed by moving the mounting holder 1335 back and forth. Accordingly, the distance required for the movement of the mounting holder 1335 is required, and the total length of the viewfinder becomes longer accordingly.
[0113]
If it comprises as FIG. 21, the attachment holder 1335 will become unnecessary. The magnifying lens 1336a is made of a flexible transparent material such as silicon resin. In the magnifying lens 1336a, the edge (lens side surface, lens fixing portion) is sandwiched between pressurizing means such as a rainbow diaphragm. The rainbow aperture is attached to the outer casing 211, and the aperture of the rainbow aperture is changed by moving the aperture knob 212.
[0114]
When the hole of the rainbow aperture stop 213 is large as shown in FIG. 22A, the center thickness of the magnifying lens 1336a is thin. Therefore, the focal point f of the magnifying lens 1336a₁Is long. On the other hand, when the hole is large as shown in FIG. 22B, the center thickness of the magnifying lens 1336a is thick. Therefore, the focal point f of the magnifying lens 1336a₂Becomes shorter. As described above, the focus of the lens 1336a can be changed by the diaphragm knob 212, and the focus adjustment can be easily performed. Therefore, the mounting holder 1335 is not necessary.
[0115]
The magnifying lens 1336a can be made of natural rubber, synthetic rubber or the like in addition to the silicon resin mentioned above, and a liquid crystal lens can also be applied. A liquid crystal lens is one in which a liquid crystal is sandwiched between two electrodes. By applying a voltage to the electrode, the refractive index of the liquid crystal changes and the focal length f of the liquid crystal lens can be changed. In this case, no rainbow aperture is required.
[0116]
Examples of the liquid crystal display panel 1333 include a TN liquid crystal display panel and an STN liquid crystal display panel, and other ferroelectric liquid crystal display panels, antiferroelectric liquid crystal display panels, cholesteric liquid crystal display panels, and the like can also be used. A display panel to which PLZT is applied can also be used. That is, any transmissive display panel can be used. In addition, a polymer-dispersed liquid crystal display panel can also be used. The panel is a liquid crystal in a mode that modulates light by transmitting and scattering light, and uses a polarizing plate, so that the light use efficiency is very high.
[0117]
In the case where a TN or STN liquid crystal display panel is used as the liquid crystal display panel 1333, the liquid crystal display panel is general and well known and will not require explanation. However, when a PD liquid crystal display panel is used as the liquid crystal display panel 1333, it is considered that explanation is necessary.
[0118]
The operation of the PD liquid crystal display panel will be briefly described with reference to FIGS. 24A and 24B are explanatory diagrams of the operation of the PD liquid crystal display panel. In FIGS. 24A and 24B, water droplet liquid crystal (hereinafter referred to as water droplet liquid crystal 245) is dispersed in the polymer 246. A TFT (not shown) or the like is connected to the pixel electrode 244, and a voltage is applied to the pixel electrode 244 by turning on / off the TFT to change the liquid crystal alignment direction on the pixel electrode 244 to modulate light. As shown in FIG. 24A, in the state where no voltage is applied, each water droplet-like liquid crystal 245 is aligned in an irregular direction. In this state, a difference in refractive index occurs between the polymer 246 and the water droplet liquid crystal 245, and the incident light is scattered.
[0119]
Here, as shown in FIG. 24B, when a voltage is applied to the pixel electrode 244, the molecules of the water droplet liquid crystal 245 are aligned. If the refractive index when the liquid crystal molecules are aligned in a certain direction is matched with the refractive index of the polymer 246 in advance, the incident light is emitted from the array substrate 242 without being scattered.
[0120]
  Reference examples related to the present inventionAs a liquid crystal material used for a liquid crystal display panel such as a viewfinder, nematic liquid crystal, smectic liquid crystal, and cholesteric liquid crystal are preferable, and a single or two or more kinds of liquid crystal compounds or a mixture containing substances other than liquid crystal compounds may be used. .
[0121]
Of the liquid crystal materials described above, the extraordinary refractive index n_eAnd ordinary light refractive index n_oCyanobiphenyl nematic liquid crystal with a relatively large difference or fluorine or chloro nematic liquid crystal that is stable over time is preferable. Among them, chloro nematic liquid crystal has good scattering characteristics and hardly changes over time. Most preferred.
[0122]
As the polymer matrix material, a transparent polymer is preferable. As the polymer, a photo-curing type resin is used in view of easiness of the manufacturing process and separation from the liquid crystal phase. Specific examples include ultraviolet curable acrylic resins, and those containing acrylic monomers and acrylic oligomers that are polymerized and cured by ultraviolet irradiation are particularly preferred. Among these, a photocurable acrylic resin having a fluorine group is preferable because it can produce a light modulation layer (liquid crystal layer) 248 with good scattering characteristics and hardly changes with time.
[0123]
The liquid crystal material has an ordinary refractive index n₀Is preferably 1.49 to 1.54, and in particular, the ordinary refractive index n₀Is preferably 1.50 to 1.53. Moreover, it is preferable to use a material having a refractive index difference Δn of 0.20 or more and 0.28 or less. n₀, Δn increases, heat resistance and light resistance deteriorate. n₀, Δn is small, the heat resistance and light resistance are improved, but the scattering characteristics are lowered, and the display contrast is not sufficient.
[0124]
From the above, as a constituent material of the light modulation layer 248, ordinary light refractive index n₀It is preferable to use a photocurable acrylic resin having a fluorine group as a resin material, using a chloro nematic liquid crystal having a ratio of 1.50 to 1.53 and Δn of 0.20 to 0.28.
[0125]
Examples of such a polymer-forming monomer include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, neopentyl glycolide acrylate, hexanediol diacrylate, diethylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, and trimethylolpropane. Triacrylate, pentaerythritol acrylate and the like.
[0126]
Examples of the oligomer or prepolymer include polyester acrylate, epoxy acrylate, polyurethane acrylate and the like.
[0127]
Further, a polymerization initiator may be used in order to carry out the polymerization quickly. Examples thereof include 2-hydroxy-2-methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck), 1- (4-Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one ("Darocur 1116" manufactured by Merck & Co., Inc.), 1-bidoxycyclohexyl phenyl ketone ("Irgacure 184" manufactured by Ciba Gaiky), benzylmethyl ketal ( Ciba Geigy's “Irgacure 651”) and the like. In addition, a chain transfer agent, a photosensitizer, a dye, a crosslinking agent, and the like can be appropriately used as optional components.
[0128]
The refractive index n when the resin material is cured_pAnd the ordinary refractive index n of the liquid crystal_oIs approximately the same. When an electric field is applied to the liquid crystal layer 248, the liquid crystal molecules are aligned in one direction, and the refractive index of the liquid crystal layer 248 is n_oIt becomes. Therefore, the refractive index n of the resin_pAnd the liquid crystal layer 248 is in a light transmission state. Refractive index n_pAnd n_oIf the difference is large, the liquid crystal layer 248 is not completely transparent even when a voltage is applied to the liquid crystal layer 248, and the display luminance is lowered. Refractive index n_pAnd n_oIs preferably within 0.1, and more preferably within 0.05.
[0129]
Although the ratio of the liquid crystal material in the PD liquid crystal layer is not specified here, it is generally about 60% to 95% by weight, preferably about 70% to 90% by weight. If it is 50% by weight or less, the amount of liquid crystal droplets is small and the scattering effect is poor. On the other hand, when the content is 90% by weight or more, the tendency for the polymer and the liquid crystal to phase separate into two upper and lower layers becomes stronger, the ratio of the interface becomes smaller, and the scattering property is lowered. The structure of the polymer-dispersed liquid crystal layer varies depending on the liquid crystal fraction. In general, the liquid crystal droplets exist as independent droplets at 50% by weight or less, and when the content is 50% by weight or more, the polymer and the liquid crystal become a continuous layer. .
[0130]
The average particle size of the water droplet-like liquid crystal 245 or the average pore size of the polymer network is preferably 0.5 μm or more and 2.0 μm or less. Among these, 0.6 μm or more and 1.5 μm or less is preferable. When the light modulated by the PD liquid crystal display panel is a short wavelength (for example, B light), the light is small, and when the light is a long wavelength (for example, R light), the light is increased. When the average particle diameter of the water droplet-like liquid crystal 245 or the average pore diameter of the polymer network is large, the voltage for setting the transmission state is lowered, but the scattering characteristics are lowered. If it is small, the scattering characteristics are improved, but the voltage for making the transmission state high.
[0131]
The average particle diameter or average pore diameter on the pixel that modulates red light is 0.8 μm to 1.5 μm, and the average particle diameter or average pore diameter on the pixel that modulates blue light is 0.5 μm to 1.0 μm. . And at least the particle diameter or hole diameter on the pixel modulating red light should be larger than that of the pixel modulating blue light. This is to improve the scattering characteristics of each pixel.
[0132]
  Reference examples related to the present inventionThe polymer-dispersed liquid crystal refers to the water-drop-like liquid crystal 245 (see FIG. 24) in which the liquid crystal is dispersed in the form of water droplets, the resin is sponge-like (polymer network), and the liquid crystal is filled between the sponge-like resins. It corresponds to what was done. The polymer-dispersed liquid crystal includes one in which liquid crystal and resin are alternately stacked to form a layer (JP-A-6-208126 and JP-A-6-202085). The polymer-dispersed liquid crystal includes one in which the liquid crystal is sealed in a capsule-shaped storage medium and the space between the capsules is filled with a resin (Japanese Patent Publication No. 3-52843). Furthermore, the polymer-dispersed liquid crystal includes those in which a dichroic or polychromatic dye is contained in a liquid crystal or a resin (polymer 246).
[0133]
The film thickness of the liquid crystal layer 248 is preferably in the range of 5 to 20 μm, and more preferably in the range of 8 to 15 μm. If the film thickness is thin, the scattering characteristics are poor and the contrast cannot be obtained. Conversely, if the film thickness is thick, a high voltage drive must be performed, and a gate drive circuit that generates a signal for turning on and off the TFT on a gate signal line (not shown) It becomes difficult to design a source drive circuit (not shown) for applying a video signal to a source signal line (not shown).
[0134]
For controlling the film thickness of the liquid crystal layer 248, black glass beads or black glass fibers, or black resin beads or black resin fibers are used. In particular, black glass beads or black glass fibers are preferable because they have a very high light absorption property and are hard, so that a small number of particles can be dispersed in the liquid crystal layer 248. It is also effective to form an insulating film on at least one of the pixel electrode and the counter electrode.
[0135]
Insulating films include alignment films such as polyimide used for TN liquid crystal display panels, organic substances such as polyvinyl alcohol (PVA), SiO₂And the like. An organic material such as polyimide is preferable from the viewpoint of adhesion and the like. The point of using polyimide as the insulating film is particularly useful.
[0136]
In the PD liquid crystal display panel, it is also important to prevent electromagnetic coupling between the signal line and the pixel electrode. An alternating current is constantly applied to the source signal line 249 in FIG. Accordingly, electric lines of force are generated between the pixel electrode 244 and the source signal line 249 in FIG. 23, and liquid crystal molecules are aligned on the electric lines of force, and “light loss” is generated from the periphery of the pixel electrode 244 and the like.
[0137]
As a countermeasure against this “light loss”, the source signal line 249 and the gate signal line and the vicinity of the signal line are shielded with a material having a relative dielectric constant lower than that of the liquid crystal layer 248 (hereinafter referred to as a low dielectric material). Low dielectric material is SiO₂Inorganic materials such as SiNx, polymers of the liquid crystal layer 248, organic materials such as resist and PVA are exemplified. In addition, it should be remembered that there is a configuration using a PD liquid crystal display panel and a polarizing plate. By disposing a polarizing plate on at least one of the light incident side and the light emitting side of the PD liquid crystal display panel, the display contrast can be greatly improved.
[0138]
In FIG. 23A, the average particle diameter of the water droplet liquid crystal 248 or the average pore diameter of the polymer network is changed corresponding to the color of the color filter 230. At least that of the red pixel is made larger than that of the blue pixel. As a method of changing the average particle diameter, a PD liquid crystal display panel is provided with a mask corresponding to red (R), green (G), and blue (B) pixels and having a different amount of transmitted ultraviolet light for each of R, G, and B. It may be disposed on the panel surface at the time of manufacture, and the panel is irradiated with ultraviolet rays through the mask to polymerize the resin of the liquid crystal layer 248. Where the UV irradiation intensity is weak, the average particle size and the like are large, and the strong part is small.
[0139]
As shown in FIG. 23B, a configuration in which the film thickness of the liquid crystal layer 248 is changed for each of R, G, and B pixels is also important. The film thickness of the liquid crystal layer 248 can be achieved by forming transparent resins 231a and 231b as shown in the figure. Examples of the transparent resin 231 include gelatin, polyimide, UV resin, and epoxy resin. The transparent resin 231 may be formed on the counter electrode 243 as shown in the figure, and conversely, the counter electrode 243 may be formed on the transparent resin 231. Further, it may be formed directly on the pixel electrode 244.
[0140]
As shown in FIG. 23B, the liquid crystal layer 248 of the pixel corresponding to the R color is made thicker than the liquid crystal layer 248 of the pixel corresponding to the B color. This is because it is necessary to increase the average particle size and the like for the R light. It can be considered that the average particle diameter is approximately proportional to the wavelength of light to be modulated. On the other hand, when the average particle size is increased, the voltage required for the light transmission state is reduced with respect to the same liquid crystal film thickness. The film thickness of the R light liquid crystal layer is preferably different by 1 μm or more than that of the B light. Alternatively, the R light liquid crystal layer is preferably formed to have a thickness of 1/10 or more thicker than that of the B light.
[0141]
In FIG. 23B, the color filter 230 is not shown. Even without a color filter, a microlens array 1224 is attached to a liquid crystal display panel 1333 as shown in FIG. 122 (b), and the same color light from the light source 1221 is separated into R, G, and B light by a dichroic mirror. What is necessary is just to inject into 244a, 244b, 244c. That is, one microlens is assigned to three pixels.
[0142]
In FIG. 2, the tip of the lamp 11 is configured to face the liquid crystal display panel 1333. However, in this configuration, since it is necessary to secure the length of the lamp 11, the total length of the viewfinder becomes long. FIG. 25 solves this problem. The side surface of the lamp 11 is arranged toward the liquid crystal display panel 1333. 26 is a cross-sectional view taken along line AA ′ of FIG. The lamp 11 is attached to the base substrate 14 via a socket 27. The reflective surface 22a has a two-dimensional parabolic shape, and the reflective surface 22b has a three-dimensional parabolic shape.
[0143]
The reflection surface 22 b collects light from the tip of the lamp 11 and illuminates the liquid crystal display panel 1333 as parallel light. The light emitting part of the lamp 11 is positioned substantially at the focal position of the reflecting surface 22b. The reflection surface 22a is substantially parallel to the side surface of the lamp 11. In addition, a reflective film 91 is formed on the back surface of the lamp 11 (location facing the lamp 11 and the reflective surface 22a) with the side surface of the lamp 11 as the center. If there is no reflective film 91, the light beam 51a is emitted.
[0144]
The light beam 51a hits the reflection surface 22a and becomes reflected light 51c. However, 51c only hits the lamp 11 and hardly emits light to illuminate the liquid crystal display panel. When the reflective film 91 is present, the light generated by the lamp 11 hits the reflective film 91 and becomes a reflected light beam 51b, which brightens the front surface of the lamp and brightens the liquid crystal display panel 1333.
[0145]
FIG. 27 is a configuration diagram of a viewfinder that employs the illumination optical system in the arrangement state of the lamp 11 of FIG. Compared to FIG. 1, the total length of the viewfinder can be shortened.
[0146]
Hereinafter, a configuration in which the lamp 11 is arranged as shown in FIG. 26 is called a lamp vertical arrangement or a lamp vertical arrangement illumination system, and a configuration in which the lamp 11 is arranged as shown in FIG. 2 is called a lamp horizontal arrangement or a lamp horizontal arrangement illumination system.
[0147]
In the configuration of the lamp vertical arrangement, it is necessary to consider the arrangement direction of the filament 24 of the lamp 11. Hereinafter, the reason and the configuration will be described sequentially.
[0148]
FIG. 28B shows the arrangement of the filament 24 and the anode electrode 25. It is assumed that the anode electrode 25 has a planar shape. The longitudinal direction of the filament 24 and the longitudinal direction of the anode electrode 25 are arranged so as to be orthogonal to each other.
[0149]
FIG. 28A shows a measurement of the luminance distribution in the circumferential direction of the lamp case 21 in the arrangement state of the filament 24 and the anode electrode 25 as shown in FIG. It is assumed that the lamp case 21 is not formed with the reflective film 91 or the like. As is apparent from FIG. 28A, the luminance is highest at 45 degrees (DEG.) And 315 degrees. Also, the brightness is lowest at 0 degrees and 180 degrees.
[0150]
The thermoelectrons emitted from the filament 24 are accelerated by the anode voltage of the anode electrode 25. Therefore, the greater the potential difference between the filament 24 and the anode electrode 25, the greater the acceleration and the greater the amount of ultraviolet light that is generated. Since the point A of the filament 24 shown in FIG. 28B is GND, the potential difference between the anode electrodes 25 is large. Therefore, as shown in FIG. 28 (a), the emission luminance is highest at the angle between the longitudinal direction of the filament 24 (0 degree-180 degrees) and the longitudinal direction of the anode electrode 25 (90 degrees-270 degrees). When the display panel 1333 or the like is illuminated with a light-emitting element, it is more advantageous that the surface with the highest luminance is directed to the display panel 1333. Therefore, an angle range of ± 30 degrees about the GND side of the filament 24 may be directed to the liquid crystal display panel 1333.
[0151]
In the case of the vertical lamp arrangement, in order to maximize the light emitted from one side surface of the lamp 11, it is preferable to form a reflective film 91 on the inner one surface of the lamp case 21, as shown in FIG. Further, as shown in FIG. 29B, the lamp case 21 may be formed on one side. The portion where the reflective film 91 is formed is SiO to prevent oxidation.₂, SiN_xIt is preferable to form a protective film 291 or the like.
[0152]
In FIG. 28B, the amount of ultraviolet rays generated is small in the A and B directions, and the amount of ultraviolet rays is large in the C and D directions. Further, the acceleration rate of the thermal electrons is determined by the distance between the anode electrode 25 and the filament 24 and the potential difference. Therefore, if the variation in the positions of the anode electrode 25 and the filament 24 is large, the variation in the emission luminance for each lamp 11 also increases. In the configuration in which the filament 24 and the anode 25 are disposed at the tip of the terminal 16 as shown in FIG. 29, the positions of the filament 24 and the anode electrode 25 are likely to vary.
[0153]
FIG. 30 shows a structure for solving the above problem. The filament 24 and the anode electrode 25 are fixed to one mounting glass 301. For this reason, the filament 24 and the anode electrode 25 can be completely fixed, and the positional relationship can be made with high precision. Therefore, the manufacturing yield can be increased because there is little variation in the light emission luminance for each lamp 11. The longitudinal direction of the filament 24 is the longitudinal direction of the lamp case 21. Therefore, the amount of ultraviolet irradiation to the A surface can be increased, and the light emission luminance of the A surface is improved.
[0154]
The point A of the filament 24 is GND, and the potential difference from the anode electrode 25 is the largest. Therefore, the anode electrode 25 should be disposed close to the point A of the filament 24. In addition, the anode electrode 25 increases the reflectance. This is because the anode electrode 25 serves as a reflective film. In addition, the shadow of the filament 24 may appear on the A surface, but this can be reduced if the film thickness of the phosphor 23 is appropriately adjusted.
[0155]
As shown in FIG.Reference examples related to the present inventionThe light emitting element emits light with the highest brightness on the A side (light emitting region 311). We will explain later how to increase the brightness of some areas.Reference examples related to the present inventionThis is because it is suitable for a viewfinder. In FIG. 30, the longitudinal direction of the filament 24 is arranged in the longitudinal direction of the lamp case 21, but the present invention is not limited to this, and the filament 24 may be arranged in the diameter direction of the lamp case 21. In this case, the light emitting region (A surface) 311b is as shown in FIG.
[0156]
  Reference examples related to the present inventionThe lamp 11 is used with the A side of FIG. 30 facing the front. For this reason, it is necessary to consider the direction of the filament 24 and the like when incorporated in a viewfinder or the like. Therefore, when manufacturing the lamp 11, it is preferable to draw a marker 312 made of a black line or the like on the outer surface of the lamp case 21 as shown in FIG. Further, a recessed portion 313 (see FIG. 31C) is attached to the lower portion of the lamp case 21.
[0157]
It is also effective to form transparent protrusions 314 (triangular prisms, triangular panes, etc.) in the light emitting region 311 as shown in FIG. The transparent protrusion 314 sharpens the directivity of light and can increase the luminance, so that the light utilization rate can be improved.
[0158]
A diffusion sheet 15 is disposed between the lamp 11 and the liquid crystal display panel 1333. As an arrangement state, as shown in FIG. 32A, a configuration may be adopted in which the lamp 11 is arranged on a part of the front surface. Alternatively, as shown in (b), a character shape of ohm (Ω) may be used and the lamp 11 may be wound around about a half of the entire circumference. The diffusion sheet 15b may be small (it is not necessary to cover the entire light emitting surface of the parabolic mirror 12) because it is difficult to see the gap between the lamp 11 and the light emitting portion. Further, the diffusion sheet 15c may be arcuate as shown in (c), or may be flat as shown in (d). Note that FIG. 33B shows the ratio of straight light, and the smaller the value, the higher the diffusivity. The same applies to other drawings.
[0159]
The diffusion sheet 15 does not need to have a uniform diffusion performance throughout the sheet. For example, as shown in FIG. As shown in FIG. 33, the diffusion degree is increased at the center of the lamp 11 and the periphery is decreased. The diffusion sheet 15 makes it difficult to see the light emission shape of the lamp 11 when the observer views the display panel 1333. When the observer changes the direction of looking through the magnifying lens 1336, the light emission image of the lamp 11 is moved according to the viewing direction. Therefore, the diffusing portion 331 of the diffusing sheet 15 only needs to have a size that can cover the moving area of the light emission image of the lamp 11.
[0160]
FIG. 33 shows a case where the lamps are arranged vertically, but it goes without saying that the arrangement shown in FIG. Further, the diffusion unit 331 does not need to cover the entire lamp 11. For example, as shown in FIG. 35, the left diffusing unit 331a and the right diffusing unit 331b may be composed of two parts. This is because it is only necessary to make the movement of the light emission image of the lamp 11 difficult to see. Further, it is not necessary to be one diffusion portion, and dot-like diffusion points 332 may be formed as shown in FIG.
[0161]
The above is the case where the diffusion portion 331 or the diffusion point 332 is formed on the diffusion sheet 15. Alternatively, a diffusion point 332 may be formed on the surface of the lamp 11 as shown in FIG. Further, as shown in FIG. 37 (b), a cap 72 to which a diffusing agent is added may be put on the lamp 11. Further, high brightness can be realized by forming the reflective film 91 on the surface of the cap 72. Examples of the reflective film 91 include a structure in which a metal reflective film such as Al is directly formed on the inner surface or outer surface of the cap 72, or a structure in which a metal reflective tube is covered. FIG. 25 shows a system in which the illumination optical system is configured with the reflecting plate 22 and the lamp 11 separated.
[0162]
In addition, there is a configuration in which the lamp 11 is inserted into the transparent holder 381 as shown in FIG. Examples of the material for forming the transparent holder 381 include glass, in addition to acrylic, polycarbonate, and epoxy resin. The reflective surface 22 is formed on the back surface of the transparent holder 381 by vapor deposition or the like.
[0163]
A configuration in which the exit surface on the diffusion sheet 15 side in FIG. 26 is a convex lens is also effective. This is because the light condensing efficiency is improved. In addition, since the convex lens and the reflective surface 22 on the back surface are combined to make the light emitted from the lamp 11 parallel light, the positive power of the reflective surface 22 and the convex lens surface is dispersed and small (the curvature is small). Tesmu).
[0164]
However, if the periphery of the lamp 11 is completely in contact with the transparent holder 381 (see FIG. 38), the heat of the lamp is easily conducted, the lamp 11 does not reach an appropriate temperature, and the light emission luminance may be reduced. . Further, it takes a long time after the lighting until the luminance reaches a predetermined value. The countermeasure is shown in FIG. A hole larger than the diameter of the lamp 11 of the transparent holder 381b is made. A protrusion (convex portion) 401 is formed in the hole. The lamp 11 is held by the protrusion 401 and fixed at the center position. Further, a slight space is formed between the lamp 11 and the transparent holder 381b. Since air has poor thermal conductivity, the air in this space provides a heat retaining effect.
[0165]
Further, by forming or arranging a prism 411 as shown in FIG. 41 (b) on the light exit surface located on the right side of the configuration of FIG. 41 (a), the light condensing efficiency is increased, and high luminance can be realized. . As shown in FIG. 41 (c), the image of the lamp 11 becomes invisible by forming or arranging a diffusion sheet 15 (or a diffusion plate) on the light exit surface located at the right end, or by embossing. Good image display can be realized.
[0166]
The lamp 11 is a hot cathode type lamp, and the light emission luminance and temperature depend greatly. In particular, at 0 degrees Celsius or less, the emission luminance may be significantly reduced.In reference examples related to the present invention,Temperature compensation is performed by using a circuit configuration and a driving method as shown in FIG.
[0167]
The temperature detection circuit in FIG. 42A includes a thermistor or a posistor whose resistance value changes with temperature, and a comparator circuit that detects that a predetermined temperature has been reached. The resistance value of the thermistor 421 decreases as the temperature decreases. Therefore R_sAnd S₁Voltage V made by_kWill change. Specifically, voltage V_kIncreases as the ambient temperature decreases. E₁And E₂Is V_kIs a reference voltage for comparison. Voltage V_kIs E₁Becomes higher than that, the output of the comparator 422a becomes a positive output. Assume that the ambient temperature at which this output is positive is set to 10 ° C. Further, the temperature drops and the voltage V_kIs the reference voltage E₂If it becomes higher, the output of the comparator 422b also becomes a positive output. It is assumed that the ambient temperature at this time is set to −10 ° C. As described above, the logical output of the comparator 422 changes depending on the ambient temperature, and the CPU 423 monitors the change in the logical output.
[0168]
When the output of the comparator 422a becomes a positive output, the CPU 423 switches the SW of the analog switch 424b.₂Close. Then resistance R₂And R_aAnd voltage V_cBecomes larger. The current flowing through the FET 426 is I_a= R_ref/ V_cTherefore, the current flowing through the anode electrode 25 increases. When the ambient temperature further decreases and the output of the comparator 422b becomes a positive output, the CPU 423 switches the SW of the analog switch 424b._ThreeClose. Then resistance R₂And R_aAnd R_bAnd the previous voltage V_cThe voltage becomes larger than that. Therefore R_refCurrent I flowing_aTherefore, the current flowing through the anode 25 is increased, and high luminance light emission can be performed.
[0169]
As the number of comparators 422 increases, the current flowing through the anode electrode 25 due to the ambient temperature can be controlled more precisely. Therefore, the temperature characteristic compensation of the lamp 11 can be performed with high accuracy. Needless to say, an IC that detects temperature (an IC that measures the temperature and outputs digitally from a plurality of manufacturers) may be used instead of the comparator 422.
[0170]
The thermistor 421 is preferably arranged in close contact with the case of the lamp 11 as shown in FIG. In particular, as shown in FIG. 47, it is preferable to attach the thermistor 421 to a place where the emission of light from the light emitting part is not hindered (the lamp bottom in the figure) and mold the periphery of the thermistor 421 with resin 471. By adopting such a configuration, temperature detection (particularly lamp temperature) accuracy is improved.
[0171]
The lighting order of the lamps 11 should also be considered. Hereinafter, the lighting method of the lamp will be described. First, an external view of a video camera is shown in FIG. The video camera will be mainly described. However, the present invention is not limited to this, and the present invention can be applied to a still camera, a head mounted display, and the like.
[0172]
The video camera includes a photographing (imaging) lens unit 432, and the photographing lens unit 432 and the viewfinder unit 1321 are back to back. FIG. 43A is a perspective view of a state where no photographing is performed. When shooting (recording), the viewfinder 1321 is placed sideways as shown in FIG. The viewfinder unit 1321 and the video camera body 432 are connected by a connection unit 434, and the connection unit 434 can change an angle of 90 degrees. The reason for doing as shown in FIG. 43B is to make it easy for the viewer of the viewfinder to see the image displayed on the liquid crystal display panel 1333 and to take a picture.
[0173]
When the viewfinder 1321 is moved sideways as shown in FIG. 43B, the pressing of the switch (SW) 433 is removed, and the switch (SW) 433 is turned on or off. Specifically, the switch (SW) 433 corresponds to a push switch. The switch (SW) 433 is connected to the voltage V in FIG.₁The SW is connected in series with the resistor R to which is applied, and the other side is grounded.
[0174]
When the SW (switch) is turned on (or turned off), the CPU 423 detects that the SW (switch) is turned on, and the CPU 423 detects the SW of the analog switch 424c._FourClose. Then, the filament voltage V_ThreeIs applied to the filament 24, and the filament 24 of the lamp 11 is heated. When a current flows through the filament 24, the lamp 11 is in a preheated state. Therefore, since the lamp 11 can emit light rapidly even at low temperatures by this preheating, the low temperature characteristics of the lamp 11 can be improved.
[0175]
Next, the recording switch 435 in FIG. 43 is turned on. The information that it is turned on is transmitted to the CPU 423, and the CPU 423 switches the SW of the analog switch 424a.₁Voltage V₂Is applied to the anode electrode 25. Voltage V₂Is a voltage higher than the sustaining voltage. At this time, the output of the inverter 171 is set to the L level. V₂Is below the discharge start voltage, the lamp 11 does not discharge. Thereafter, the CPU 423 sets the output of the inverter 171 to the H level. Then, a capacitor C is connected to the anode electrode 25.₁Since the voltage of the anode electrode 25 becomes equal to or higher than the discharge start voltage, the lamp 11 emits light. When the lamp 11 emits light, the capacitor C rapidly₁The electric charge is discharged. When performing the above operation, the reference voltage V_cIs set to a predetermined value.
[0176]
Capacitor C₁The larger the amount of charge charged to the₁The higher the voltage at both ends, the easier it is to compensate for the low temperature of the lamp 11. FIG. 44A shows a change in the voltage applied to the anode electrode 25. The dotted line in FIG.₁The charge amount is small and the discharge start voltage V is relatively high._a1Shows the change in applied voltage when C is low (C₁The boost voltage is low. When the output of the inverter 171 becomes H level, the voltage of the anode electrode 25 becomes V_a1Immediately, capacitor C₁The voltage at both ends is discharged. FIG. 44B shows the change in the light emission luminance of the lamp at that time. Since the current flowing through the anode electrode 25 of the lamp 11 is a steady-state current, it takes a long time because the brightness becomes steady as indicated by the dotted line at low temperatures.
[0177]
On the other hand, capacitor C₁Is large and relatively C₁The change in applied voltage when the boosted voltage due to is high is shown by the solid line in FIG. When the output of the inverter 171 becomes H level, the voltage applied to the anode electrode 25 is V_a2Thus, the lamp 11 normally starts discharging within 10 μsec. But C₁Since the amount of electric charge is large, as shown by the solid line in FIG. Therefore, as shown by the solid line in FIG. 44B, the light emission luminance of the lamp 11 rapidly increases even at low temperatures. By doing so, the low temperature characteristics of the lamp 11 can be compensated.
[0178]
Of course, as shown in FIG. 42 (b), it is possible to compensate for the low temperature by passing a current larger than the steady value through the filament 24 at the start of lighting. First, SW_FiveBy closing the normal filament voltage V_ThreeHigher voltage V_FourIs applied to the filament 24. After a predetermined period has passed, SW_FourBy closing the filament voltage V_ThreeIs applied to the filament 24 and the SW_Fiveopen. As described above, the low temperature compensation of the lamp 11 can be easily performed by preheating the lamp 11 by flowing an overcurrent through the filament 24 at the start of lighting of the lamp 11.
[0179]
According to the experiment, when the ambient temperature is −10 ° C., a current approximately 1.5 to 3.0 times as large as the steady anode current may be applied to perform practically low temperature compensation (25 ° as a reference). ).
[0180]
In FIG. 42, the CPU 423 compensates for the current flowing through the anode electrode 25 of the lamp 11 based on the data of the temperature detection circuit. As shown in FIG. 45, the voltage V at the + terminal of the operational amplifier 425_cA method in which the thermistor 421 is directly changed and controlled is also conceivable. The thermistor 421 becomes higher as the ambient temperature becomes lower, and the current I flowing through the anode electrode 25 is increased._aWill grow. As an example, the anode current I in the case of the circuit constant of FIG._aThis change is shown in FIG. However, B of the thermistor is 4000.
[0181]
The lamp 11 emits light with a predetermined luminance by maintaining itself at a constant temperature. Therefore, if another object touches the lamp 11, the other object (such as the parabolic mirror 12) loses heat, making it difficult to emit light (especially when the ambient temperature is low, the light emission luminance decreases). As a configuration for improving this, there is a configuration in which the parabolic mirror 12 is prevented from touching the lamp 11 as much as possible as shown in FIG. The lamp 11 is slightly in contact with or close to the parabolic mirror 12 at point A. Further, the base substrate 14 is also in contact with the three locations of the solder 29 in the form of dots. If comprised as mentioned above, it will become difficult to thermally radiate from the lamp | ramp 11, and a temperature characteristic can be made very favorable.
[0182]
As a temperature compensation of the lamp 11, there is a method of detecting the light emission luminance of the lamp 11 and applying feedback to obtain a predetermined light emission luminance. The circuit diagram is shown in FIG. The photodiode temperature compensation circuit in FIG. 49 includes a photodiode 491, a resistor, and an operational amplifier 425. The light from the lamp 11 is a photodiode PD.₁A current is excited in proportion to the amount of light irradiated to 491a and converted into a voltage by a current-voltage conversion circuit by an operational amplifier 425a. The other photodiode PD₂491b is shielded from light. Therefore, the current-voltage conversion circuit converts the dark current of the photodiode 491b into a voltage by the operational amplifier 425b. The photodiode 491 described above is disposed in the vicinity of the lamp 11.
[0183]
The reason why two photodiodes are used in this way is that the photodiode 491 has a large temperature dependency, so that the output of the two operational amplifiers 425a and 425b is canceled by the subtraction circuit of the subtraction circuit 425c (reduces the influence) of the photodiode 491b. It is. If the voltage applied to the positive terminal of the operational amplifier 425d is changed corresponding to the light amount of the lamp 11, the anode current I is reduced when the light amount of the lamp 11 is small (the light emission luminance is low)._aThe brightness of the lamp 11 can be increased to a predetermined value (desired value). On the other hand, if the luminance of the lamp 11 is high, the anode current I_aThe luminance of the lamp 11 can be lowered to a predetermined value (desired value).
[0184]
  Reference examples related to the present inventionIn the viewfinder, the observer sees the display image on the liquid crystal display panel 1333 with his / her eyes in contact with the eyepiece cover 1332 (see FIG. 1) (or with his eyes in contact with the eyepiece ring 1335). That is, the position of the observer's pupil is substantially fixed. When it is assumed that all the pixels of the liquid crystal display panel 1333 travel light straight, the magnifying lens 1336 is emitted from the lamp 11 and light incident on the effective area of the parabolic mirror 12 passes through the magnifying lens 1336. , Almost everything is incident on the observer's pupil. The magnifying lens 1336 allows the observer to magnify and view a small display image on the liquid crystal display panel 1333. That is, an enlarged virtual image can be seen.
[0185]
Since the position of the observer's pupil is almost fixed by the eyepiece cover 1332 in the viewfinder, the light source disposed behind the viewfinder may have a narrow directivity. In a conventional viewfinder that uses a light box that uses a fluorescent tube as a light source, only light that travels within a small solid angle in one direction from an area that is almost the same size as the display area of the liquid crystal display panel is used. The traveling light is not used. That is, the light utilization efficiency is very poor.
[0186]
  In reference examples related to the present invention,A light source 11 having a small luminous body (or a light emitting area is used in a limited manner) is used, and light emitted from the luminous body to a wide solid angle is converted into light almost parallel by a parabolic mirror 12 or the like. If it carries out like this, the directivity of the emitted light from the parabolic mirror 12 grade | etc., Will become narrow. If the observer's viewpoint is fixed, the narrow directional light described above is sufficient for the use of the viewfinder. Naturally, if the size of the light emitter is small, the power consumption is small.
[0187]
As aboveReference examples related to the present inventionThe viewfinder uses a viewer viewing a display image with a fixed viewpoint. A normal direct-view liquid crystal display device requires a certain viewing angle, but a viewfinder is sufficient for use if a display image can be satisfactorily observed from a predetermined direction. Therefore, the light emitting area of the lamp 11 can be small, and low power consumption can be realized.
[0188]
In addition, although the small fluorescent discharge tube was illustrated as the lamp | ramp 11, it is not limited to this. For example, a flat fluorescent lamp 521 shown in FIG. 52 can be used. In a normal flat fluorescent lamp, a region 311a surrounded by a dotted line in FIG. 52 emits light. The dotted line area 311 a is larger than the effective display area of the liquid crystal display panel 1333. In the flat fluorescent lamp 521 shown in FIG. 52, only the hatched portion 311 emits light. That is, the light emitting area is different from the flat fluorescent lamp manufactured by USHIO. It can be easily understood that the power consumption is reduced if the light emitting area is small. Further, if only light emission by the shaded portion 311 is sufficient, the external dimension of the flat fluorescent lamp 521 can be reduced.
[0189]
It is important that the light emission area of the flat fluorescent lamp 521 is smaller than the area of the effective display area of the liquid crystal display panel 1333. this isReference examples related to the present inventionThis is a matter common to the lamp 11. That is, when the light emitting element 11 is viewed from the liquid crystal display panel 1333, the visible light emitting area is smaller than the effective display area of the liquid crystal display panel 1333. For example, in the discharge tube in FIG. 2A, the application area of the phosphor 23 is a considerably wide area, but the total area of the area is not compared with the area of the effective display area of the liquid crystal display panel 1333. The area of the light emitting region that can be used effectively is regarded as the light emitting area.
[0190]
Therefore, even if the light emission area is large, if the light emitted from the lamp 11 is collected by the light collecting means such as the parabolic mirror 12 and the liquid crystal display panel 1333 cannot be illuminated, the light emission area is actually considered to be small. When the liquid crystal display panel 1333 is in a transmissive state, an area that emits light reaching the observer is recognized as a light emitting region at the time of light emission.
[0191]
Other LEDs can also be used as the lamp 11. FIG. 50 shows the LED and its explanatory diagram. In FIG. 50, reference numeral 503 denotes a resin lens, 502 denotes a light emitter, and 501 denotes a terminal. The light emitter 502 is composed of a light emitting chip. The light emitting chip is molded with a transparent resin (resin lens 503). The LED can adjust the light emission luminance by controlling the voltage or current applied to the light emitting chip.
[0192]
The surface of the LED mold resin (resin lens 503) can be used as a lens. In particular, as shown in FIG. 50 (b), it is preferable that the surface of the mold resin is a spherical surface and the light emitted from the light emitter 502 satisfies the aplanatic condition. The light emitter 502 may be disposed at a position separated from the vertex 505 of the lens surface by S = (1 + 1 / n) · r, where r is the radius of curvature of the lens surface of the mold resin and n is the refractive index.
[0193]
At this time, the image of the light emitter 502 by the lens surface 504 can be at a position 508 that is separated from the vertex 505 of the lens surface by S ′ = (1 + n) · r. Since the size of the light emitter 502 is sufficiently smaller than the diameter of the light collecting means such as the parabolic mirror 12, it can be regarded as a point.
[0194]
In FIG. 50B, 507 is the center of curvature of the lens surface 504, and 506 is the normal of the lens surface. When the LED emitter 502 is resin-molded, the exit surface is a spherical lens, and the light emitted from the emitter 502 satisfies the aplanatic condition for the spherical lens, the light incident on the spherical lens from the LED Since the sine condition is satisfied, the luminance uniformity of the liquid crystal display device as viewed from the observer is improved.
[0195]
When the LED emits monochromatic light, the light emitting chip (light emitter 502) may be one chip. When white light is used, the three chips 502a, 502b, and 502c of red, blue, and green are molded into one resin. At this time, in particular, the vicinity of the chip is molded with a resin 503b having a high light scattering property, and the outside is molded with a resin 503a having a high light scattering property. This is because, by configuring in this way, three colors of red, blue, and green are mixed and a good white color is obtained. Note that chromaticity can be easily achieved by changing the currents flowing through the three chips.
[0196]
Figure 53Reference examples related to the present inventionIt is explanatory drawing of the state which attached the viewfinder to the video camera. The viewfinder body 1321 is attached to the video main body 431 by a mounting bracket 1323. Reference numeral 1333 denotes a PD or TN liquid crystal display panel, and the diagonal length of the display screen is 0.5 inches. Reference numeral 533 denotes a drive circuit for the liquid crystal display panel 1333 shown mainly in FIG. A lamp 11 has a diameter of 2.4 mm and emits white light. A voltage is supplied from the light emitting element power supply circuit 532 to the lamp 11.
[0197]
The light emitting element power supply circuit 532 supplies the lamp 11 with a filament voltage of 2.1 V and an anode voltage (discharge maintaining) of 12 V. Both voltages are DC voltages. The anode electrode 25 is applied with a pulsed voltage of 10 [mu] sec of 18 (V) at the start of lighting.
[0198]
On the other hand, a video signal is output from the CCD sensor 531 in the image pickup means 432, applied to the video amplifier 191 of the liquid crystal display panel drive circuit 533, and an image is displayed on the liquid crystal display panel 1333. The video signal recorded on the video tape is reproduced by the reproduction circuit 534 and applied to the video amplifier 191. A battery 202 attached to the video camera main body 431 supplies power to the light emitting element power supply circuit 532, the liquid crystal display panel drive circuit 533, and the reproduction circuit 534.
[0199]
  Reference examples related to the present inventionThe viewfinder can be applied not only to a video camera but also to an electronic still camera as shown in FIG. Used as a monitor attached to the still camera body 541. Viewfinder 1333Reference examples related to the present inventionThe viewfinder configuration is applied. Since electronic still cameras have limited battery capacity,Reference examples related to the present inventionLow power consumption can be achieved by applying a viewfinder.
[0200]
The matters explained above areReference examples related to the present inventionThis applies to other viewfinders, video cameras, pocket TVs, head mounted displays, etc. in a timely manner.
[0201]
The above configuration illuminates the liquid crystal display panel 1333 by making the light from the lamp 11 parallel light by the parabolic mirror 12 or the like. However, even if it is not a parabolic mirror as shown in FIG. 55, the liquid crystal display panel 1333 can be illuminated by using the convex lens 552 to make the light emitted from the lamp 11 parallel light.
[0202]
58 (a) and 58 (b), the light emitting area of the lamp 11 may be arranged at the focal point of the convex lens 552, and the position farther than the focal distance f as shown in FIG. 58 (c). The lamp 11 may be disposed on the side.
[0203]
Further, as shown in FIG. 58 (d), the lamp 11 may be arranged within a distance shorter than the focal length f. However, in the case of the configuration as shown in FIG. 58 (d), the reflector 551 is disposed on the rear surface of the lamp 11. This is to increase the apparent light emitting area. The overall length of the viewfinder can be shortened. The viewfinder shown in FIG. 55 adopts the configuration shown in FIG.
[0204]
In addition, the illumination lens (convex lens 552) may be composed of a Fresnel lens 552a as shown in FIG. At that time, the incident surface of the Fresnel lens 552a is concave. This is to prevent the light emitted from the lamp 11 from being reflected when entering the lens. The same applies to the lens 552b in FIG. 59 (b) and the lens 552d in FIG. 59 (c). The convex lens is not limited to one, but may be composed of two or more as shown in FIG. 59 (b), or may be composed of one as shown in FIG. 59 (c). Of course, a biconvex lens may be used. Further, as shown in FIG. 60, one of the lenses 603 may be a convex surface 601 and the other surface may be a Fresnel surface 602. Of course, a plano-convex lens and a Fresnel lens may be bonded together.
[0205]
A lens used for illumination of the liquid crystal display panel 1333 such as the convex lenses 552 and 603 is preferably polycarbonate. Since the refractive index is higher than that of acrylic, the lens thickness can be reduced. Polycarbonate has a large dispersion coefficient. However, since it is used for an illumination system, no color shift occurs due to the wavelength fraction, which is practically sufficient.
[0206]
In FIG. 1, the illumination optical system includes a reflector such as a parabolic mirror 12 and a lamp 11. FIG. 55 shows an illumination optical system comprising an illumination lens 552, a lamp 11 and a reflector 551. An auxiliary lens 553 is disposed on the light emission side of the liquid crystal display panel 1333. The reflector 551 is disposed on the rear surface of the lamp 11. The lamp 11 is arranged so that the focal point f of the illumination lens 552 is positioned in front of the light emitting surface of the lamp 11 (see 58 (a)), the arrangement arranged on the rear surface of the lamp (see FIG. 58 (b)), and the lamp 11. A configuration in which the lamp 11 is disposed at a distance position longer than the focal length f (see FIG. 58C) and a configuration in which the lamp 11 is disposed within the focal length (see FIG. 58D) are exemplified. (D) is most preferable because the entire length of the viewfinder is shortened.
[0207]
The light reflected from the lamp 11 to the rear surface is reflected by the reflecting plate 551 and enters the illumination lens 552. In other words, the reflector 551 can be regarded as an increase in the luminous body image of the lamp 11 in appearance. 58 (a) and 58 (b), the light in the partial light emitting region of the lamp 11 is collected. Therefore, high luminance display can be realized if the region where light is condensed is the region where the lamp generates the highest luminance.
[0208]
As shown in FIG. 57, it is a great feature that the principal ray incident on the liquid crystal display panel 1333 is substantially perpendicular to the surface of the liquid crystal display panel 1333 by the illumination lens 552 and the auxiliary lens 553. This is because the TN liquid crystal display panel can modulate well the light incident perpendicularly to the panel surface and can realize good black display (in the NW mode). When light is incident obliquely on the panel surface of the liquid crystal display panel 1333, the alignment direction of liquid crystal molecules arranged by applying a voltage does not match the traveling direction of incident light, and light leaks from the analyzer. It becomes too much to display black.
[0209]
If there is no auxiliary lens 553, it is necessary to squeeze the light emitted from the lamp 11 toward the magnifying lens 1336 as shown in 51b. The effective diameter of the magnifying lens 1336 is usually small (to limit the direction in which the viewer views the display image on the panel 1333 and to reduce the diameter of the magnifying lens 1336 to make it compact or the like). Therefore, it is necessary to increase the positive power of the illumination lens 552 and to make the diameter of the illumination lens 552 larger than the effective diagonal length of the liquid crystal display panel 1333 (diagonal length of the screen display area). Therefore, the lens center thickness of the illumination lens 552 is inevitably increased, and the viewfinder is enlarged. Naturally, since the light incident on the liquid crystal display panel 1333 is also inclined, the display contrast is lowered. The auxiliary lens 553 has the effect of reducing the thickness of the illumination lens 552 and the effect of improving the display contrast by making the light incident on the liquid crystal display panel 1333 substantially vertical. 140 and 141 are examples of optical design.
[0210]
The illumination lens 552, the liquid crystal display panel 1333, and the auxiliary lens 553 are attached to a cylindrical body 1321b (see FIG. 55). The body 1321c to which is attached is configured to be freely movable (movable).
[0211]
FIG. 56 is a configuration diagram in which the entire length of the viewfinder is shortened by being moved. The distance between the lamp 11 and the illumination lens 552 is shortened, and the distance between the auxiliary lens 553 and the magnifying lens 1336 is also shortened. FIG. 56 is a cross-sectional view when the viewfinder is not used, and the overall length is shortened and the portability is improved. When the viewfinder is used, it is extended as shown in FIG. 55 so that the illumination lens 552 can be in a position where light emitted from the lamp 11 can be condensed well.
[0212]
The inner surface of the viewfinder body 1321 is black or dark so as to absorb light. This is to prevent the display contrast of the display panel 1333 from being lowered by the light irregularly reflected by the convex lenses 552, 553 and the like.
[0213]
Note that the auxiliary lens 553 can also be made of polycarbonate resin, as with the illumination lens 552. Polycarbonate has a higher refractive index than acrylic or the like, and can reduce the thickness of the lens, thereby reducing the weight of the viewfinder.
[0214]
As shown in FIG. 56, the filament 24 of the lamp 11 is disposed at an angle of θ from the lamp front surface position. As will be described later, θ is set to 30 degrees or more and 60 degrees or less. The reason for this will be described below with reference to FIG. A terminal 16a (see FIG. 2) is connected to the point A of the filament 24, and is set to the ground potential (GND). A terminal 16b is connected to point B of the filament 24, and a filament voltage is applied. In FIG. 9, the reflective film 91 is formed on the inner surface or outer surface of the lamp case 21.Reference examples related to the present inventionWhen used as the light-emitting element 11 of the viewfinder, the present invention is not limited to this, and an element that is not formed as shown in FIG. 8 may be used.
[0215]
FIG. 61B shows the arrangement of the filament 24 and the anode electrode 25. The anode electrode 25 is formed in a planar shape, and is attached to the tip of the terminal 16c. The longitudinal direction of the filament 24 and the longitudinal direction of the anode electrode 25 are arranged so as to be orthogonal to each other.
[0216]
Now, the luminance distribution measured in the circumferential direction with reference to the midpoint of the diameter of the lamp case 21 in the arrangement state of the filament 24 and the anode electrode 25 as shown in FIG. 61B is shown in FIG. Shown in It is assumed that the reflecting film 91 is not formed on the lamp case 21. As is apparent from FIG. 61A, the luminance is highest at 45 degrees (DEG.) And 315 degrees. Also, the brightness is lowest at 0 degrees and 180 degrees.
[0217]
The thermoelectrons emitted from the filament 24 are accelerated by the anode voltage of the anode electrode 25. Therefore, the greater the potential difference between the filament 24 and the anode electrode 25, the greater the acceleration and the greater the amount of ultraviolet light that is generated. Since the point A of the filament 24 is GND, the potential difference between the anode electrodes 25 is large. Therefore, as shown in FIG. 61 (a), the emission luminance is highest at the angle between the center of the longitudinal direction of the filament 24 (0 degree-180 degrees) and the longitudinal direction of the anode electrode 25 (90 degrees-270 degrees). is there. In the viewfinder of FIG. 55, in the case of FIGS. 58 (a) and 58 (b), it is advantageous to have the highest luminance direction facing the liquid crystal display panel 1333 side. In the case of FIG. 58 (b), it may be advantageous to arrange as shown in FIG. 28 (a).
[0218]
In any case, when the lamp 11 is regarded as a point light source and the liquid crystal display panel 1333 is illuminated, it is advantageous to arrange as shown in FIG. Therefore, in the case of FIG. 55, an angle range of 30 degrees or more and 60 degrees or less with respect to the longitudinal direction of the filament 24 may be directed to the liquid crystal display panel side.
[0219]
In addition, if it is clockwise, it is 30 degrees or more and 60 degrees or less, but if it shows counterclockwise, it is needless to say that the range of 300 degrees or more and 330 degrees is the previous 30 degrees or more and 60 degrees.
[0220]
The lowest brightness at 0 degrees and 180 degrees is due to the shadow of the filament 24. Therefore, it is not preferable to use this surface toward the A surface (the front surface of the lamp 11).
[0221]
In order to further improve the light emission luminance of the A surface, it is preferable to form a recess in the lamp case 21 as shown in FIG. This is because the emission luminance is determined by whether there is a phosphor in the vicinity of the generated ultraviolet rays. The higher the ultraviolet density, the higher the emission luminance. However, if it is too close to the filament 24, the oxide of the filament 24 may be scattered on the phosphor and blackened, resulting in a decrease in luminance. In any case, as shown in FIG. 61 (c), if a dent, a concave portion or a flat portion is formed, the generated ultraviolet rays are effectively irradiated onto the phosphor, and the emission luminance of the A surface (light emitting surface) is increased.
[0222]
In consideration of the arrangement direction of the filament 24 of the lamp 11 described with reference to FIG. 61, the method of configuring the viewfinder with the highest light emission luminance portion directed at the object can be applied to other display devices. In addition,Reference examples related to the present inventionA display device having light emitting means and a display panel corresponds to the viewfinder of the present invention. Accordingly, the viewfinder of the present invention also includes a monitor unit used in a video camera, a pocket TV, a display unit of a mobile phone, a display unit of an electronic still camera, a direct-view liquid crystal television, a head-mounted display, and the like. Therefore, as described in this specificationReference examples related to the present inventionThe configuration method can be applied not only to other video cameras but also to the following display devices.
[0223]
FIG. 62 is an explanatory diagram when the method of FIG. 61 is applied to a direct view display device. As shown in FIG. 62, the filaments 24 in the lamp 11 are arranged to be inclined in a predetermined direction as shown in FIG. 61, and the A surface is arranged toward the edge portion of the light guide plate 621. The rear surface of the lamp 11 is covered with a reflecting plate 551 or the like to increase the output light to the A surface. Examples of the reflection plate 551 (or reflection film) include Silver Lux manufactured by Sumitomo 3M Limited. In addition, a large number of sheets with a reflectance of 90% or more on which Al is deposited are commercialized. Of course, a reflector such as Al may be used.
[0224]
It is more preferable that the A surface is recessed to increase the light emission luminance. Light radiated from the lamp 11 is reflected while being reflected in the light guide plate 621, and is scattered when entering the diffusion portion (622 f), and a light beam is emitted toward the display panel 1333. The diffusion plate 15 is for preventing the pattern of the diffusion portion 621 from being seen. Further, as the distance from the lamp 11 increases, the formation area of the diffusion portion 622 increases. This is to make the luminance of the light guide plate 621 uniform.
[0225]
Since the lamp 11 is a hot cathode system, the anode current I_aThe display brightness of the light guide plate 621 can be easily adjusted simply by adjusting the. In addition, since light is emitted at a DC low voltage of 20 (V) or less, a high voltage is not required unlike a cold cathode lamp, and radio wave radiation noise is not generated.
[0226]
Naturally, a reflection plate 551 made of metal may be used as shown in FIG. The reflector 551 is made larger than the horizontal width of the display area of the display panel 1333. What is necessary is just to comprise using the reflective sheet etc. which were illustrated previously. In addition, a prism plate 631 may be provided to increase the light incident on the display panel 1333. Since the light emission pattern of the lamp 11 may be displayed as it is, the diffusion plate 15 is disposed between the lamp 11 and the display panel 1333.
[0227]
The viewfinder shown in FIG. 55 has a configuration in which the effective diameter of the illumination lens 552 is smaller than the opening of the reflector 551.
[0228]
It is effective to make the reflecting plate 551 close to the lamp 11 and to have a large area as shown in FIG. This is because the lamp 11 can be brought close to the illumination lens 552 and the entire length of the viewfinder can be shortened. By making the reflecting plate 551 larger than that in FIG. 55, the apparent light emitting area of the lamp 11 is increased.
[0229]
In FIG. 64, a light beam 51a emitted from the front surface (region a) of the lamp 11 is directly incident on the illumination lens 552, passes through the liquid crystal display panel 1333, the auxiliary lens 553, and the magnifying lens 1336, and the eye point 641 of the observer. Incident (observer's pupil). On the other hand, the light emitted from the side surface (b region) of the lamp 11 is reflected once by the reflecting plate 551, enters the illumination lens 552, becomes a light beam 51b, and enters the eye point 641 of the observer. Further, the light emitted from the rear surface (region c) of the lamp 11 is reflected by the reflecting plate 551, returns to the lamp 11 and is scattered again by the phosphor 23, and contributes to improving the luminance of the lamp 11. That is, in the configuration of FIG. 64, the light emitted from the entire periphery of the lamp 11 can be used effectively, and the light use efficiency is high.
[0230]
Note that the opening diameter k of the reflection plate 551 is preferably d / 2 <k, where d is the width of the effective display area of the liquid crystal display panel 1333 (4 for a 4: 3 screen).
[0231]
The configuration in FIG. 64 is configured by separating the lamp 11 and the reflection plate 551 (or reflection sheet). As shown in FIG. 65, a configuration in which a transparent resin 381 is filled between the reflecting plate 551 and the lamp 11 is also effective. This is because there is an effect of keeping the lamp 11 warm by the transparent resin 381 and an effect of preventing damage due to impact. Furthermore, as shown in FIG. 66, it is effective to make the light exit surface of the transparent resin (transparent holder 381) into a convex lens shape (or a squirrel-like shape). This is because the light exit surface functions as a lens having a positive power and the thickness of the illumination lens 552 can be reduced.
[0232]
As a matter of course, the transparent resin may be made of a transparent inorganic material such as glass. In addition, as shown in FIG. 40, a configuration in which a slight space is provided between the lamp 11 and the transparent resin (transparent holder 381) to improve the heat retaining effect of the lamp 11 is also effective. Further, the illumination lens 552 and the reflection plate 551 may be integrated as shown in FIG.
[0233]
In the configuration of the viewfinder using the auxiliary lens 553 as shown in FIG. 55, it is a problem that dust adheres to the flat portion of the auxiliary lens 553. This is because dust may be seen by an observer near the display surface of the liquid crystal display panel 1333. Therefore, the plane portion of the auxiliary lens 553 needs to be 3 mm or more, preferably 5 mm or more, from the light emitting surface of the display panel 1333. As another configuration, as shown in FIG. 68, a method of fitting the auxiliary lens 553 into the panel holder 681 and sealing between the light emitting surface of the display panel 1333 and the auxiliary lens 553 to prevent the entry of dust is also effective. According to this configuration, dust does not adhere to the flat surface portion of the auxiliary lens 553, and dust does not adhere to the surface of the display panel 1333. The auxiliary lens 553 may be resin-molded according to the size of the opening of the panel holder 553. In order to further improve the sealing performance, a cushioning material such as rubber may be interposed between the panel holder 681 and the auxiliary lens 553.
[0234]
It is also effective to inject a transparent resin 381 between the auxiliary lens 553 and the display panel 1333 so as to be integrated. A transparent resin 381 having a refractive index substantially equal to that of the auxiliary lens 381 is selected. Examples include acrylic adhesives, silicon gel, ethylene glycol, and epoxy adhesives. According to this configuration, the interface reflection of the auxiliary lens 553 is eliminated and the light transmittance is improved. Further, the liquid crystal display panel 1333 and the auxiliary lens 553 eliminate interference and improve image display quality.
[0235]
In FIG. 56, when the viewfinder is not used, the distance between the illumination lens 552 and the lamp 11 is shortened to improve portability. However, even if the interval is shortened, the thickness d of the illumination lens 552 as shown in FIG.₁And the diameter d of the lamp 11₂It cannot be shorter than the length of the plus.
[0236]
In order to solve this, there is a method in which the lamp 11 is disposed below the illumination lens 552 during storage as shown by the dotted line in FIG. The lamp 11 can be rotated 90 degrees around the point A. A view seen from the lateral direction is shown in FIG. The liquid crystal display panel 1333 needs to be attached to the panel holder 681 in order to hold it. The length of the illumination lens 552 in the vertical direction may be the vertical length of the liquid crystal display panel 1333 (for example, 9 when the panel is 16: 9) + α. Therefore, the space of the upper and lower part of the illumination lens 552 is made. In particular, the size of the liquid crystal display panel 1333 is remarkable when it is horizontally long like a wide panel. The lamp 11 is housed in this space by rotating it 90 degrees.
[0237]
As the storage mechanism, first, the lamp 11 is rotated about the point A and laid sideways. Next, the illumination lens 552 and the liquid crystal display panel 1333 are shifted rearward as shown in FIG. A person skilled in the art will easily consider the lamp rotation mechanism and the like. The key point is that there is space above and below the illumination lens 552.
[0238]
A configuration in which the lamp 11 is removed from the optical axis is also conceivable. This method is shown in FIGS. The lamp 11 is attached to a socket 711, and a knob 712 is attached to the socket 711. The observer grasps the knob 712 and pulls out the lamp 11 from the optical axis 715 as shown in FIG. 72 when stored (when the viewfinder is changed from the use state to the non-use state). Next, when the lamp 11 is pulled out, the illumination lens 552, the liquid crystal display panel 681, and the like are moved backward by a motor or the like to be in the state shown in FIG.
[0239]
The magnifying lens 1336 is preferably attached to the cylindrical body 714 and separated from the body 713. Then, at the same time as the illumination lens 552 is lowered rearward, it is accommodated in the body 713 as shown in FIG. Such a configuration is easy. For example, there is a configuration in which a photographing lens protrudes forward when a switch is turned on in a compact camera. This mechanism may be adopted. It may be possible to mechanically lower the illumination lens 552 backward with the same configuration.
[0240]
The configuration in which the lamp 11 is pulled out from the optical axis 715 according to FIG. 73 or the configuration in which the lamp 11 is stored below or above the illumination lens 552 as shown in FIG. 70 can greatly reduce the overall length of the viewfinder. Becomes better. Further, by storing the body 714 holding the magnifying lens 1336 in the body 713, the overall length can be significantly shortened.
[0241]
In FIG. 68, the auxiliary lens 553 is fitted into the panel holder 681, but it is preferable that the illumination lens 552 is fitted into the panel holder 681 as shown in FIG. This is because there is no dust on the back surface of the liquid crystal display panel 1333 and a good image display can be realized. Further, a transparent resin 381b or the like is filled between the illumination lens 552a and the liquid crystal display panel 1333, so that the interface loss is eliminated and the light utilization rate is improved. Needless to say, the magnifying lens 1336, the auxiliary lens 553, the illumination lens 552a, and the like can be replaced with a Fresnel lens.
[0242]
As a method for shortening the total length of the viewfinder, there is a configuration in which the optical axis 715b of the lamp 11 and the optical axis 715a of the magnifying lens 1336 are substantially orthogonal as shown in FIG. A mirror 751 is disposed to bend the optical axis 715. Light from the lamp 11 is collected by the illumination lens 552 and bent by the mirror 751 to illuminate the liquid crystal display panel 1333. Compared to FIG. 71, the depth d can be shortened. For easier understanding, a perspective view at that time is shown in FIG. The arrangement direction of the lamp 11 may be the direction shown in FIG. 76, the direction shown in FIG. 77, or the vertical direction as shown in FIG. Further, the illumination lens 552 may be replaced with a Fresnel lens 552b as shown in FIG.
[0243]
Further, as shown in FIG. 80, there is also a configuration in which the liquid crystal display panel 1333 is arranged horizontally. It is promising as a configuration that shortens the overall length. In particular, it is desirable to adopt the configuration in which a space can be taken above the viewfinder.
[0244]
Next, the illumination lens 552 is a planar light collecting means such as a Fresnel lens, and a diffusion plate (sheet) 15a is disposed between the Fresnel lens 552 and the liquid crystal display panel 1333.Reference examples related to the present inventionThe viewfinder will be described.
[0245]
  Reference examples related to the present invention are:Similarly to the above, the lamp 11 having a small light emitting area is used, and light emitted from the light emitting area to a wide solid angle is converted into light almost parallel by the Fresnel lens 552. If it carries out like this, the directivity of the emitted light from a lens will become narrow. If the observer's viewpoint is fixed, the narrow directional light described above is sufficient for the use of the viewfinder. As described above, if the size of the light emitting area is small, the power consumption is naturally small.
[0246]
As aboveReference examples related to the present inventionThe viewfinder uses a viewer viewing a display image with a fixed viewpoint. A normal direct-view liquid crystal display device requires a certain viewing angle, but a viewfinder is sufficient for use if a display image can be satisfactorily observed from a predetermined direction.
[0247]
The viewfinder shown in FIG. 83 uses a Fresnel lens 552 to collect the light emitted from the lamp 11. The Fresnel lens 552 is manufactured using acrylic plastic or glass such as BK7. The Fresnel lens 552 has a state in which when the light from the lamp 11 is incident on the display panel 1333, the light becomes substantially parallel light. The plane of the Fresnel lens 552 is provided with a single-layer antireflection coating to prevent light reflection.
[0248]
In FIG. 83, one lens is used as the Fresnel lens 552, but a plurality of lenses may be used as in FIG. The same applies to the illumination lens 552 and the like in FIG. 55 and the like, but the lens is preferably an aspherical surface such as an elliptical surface. If an aspherical surface is used, the peripheral portion of the display panel 1333 can be well illuminated, and the light amount ratio (peripheral light amount ratio) between the central portion and the peripheral portion of the display panel 1333 can be increased.
[0249]
Note that the light on the rear surface of the lamp 11 is reflected as indicated by the reflector 831. The F values of the magnifying lenses 1336a and 1336b are about 3.5 to 4.5, respectively. Therefore, it is preferable that the F value of light incident on the display panel 1333 (the F value of the illumination system) be less than that. Of course, the magnifying lens 1336a may be composed of a single lens as shown in FIG.
[0250]
The F value of the illumination light is specifically 4 or less. The F value is a design matter determined by the distance between the display panel 1333 and the lamp 11, the effective diagonal length of the display panel 1333, and the power of the Fresnel lens 552. The area of the light emitting region of the lamp 11 is 1 mm to 10 mm in diameter.
[0251]
In particular, when a TN liquid crystal display panel is used as the light modulation means (liquid crystal display panel 1333), the diameter is generally set to 1/10 or more and 1/2 or less of the effective diagonal length of the panel. Preferably, it is 1/8 or more and 1 / (2.5) or less. For example, in the case of 0.5 inch, the diameter is 2 mm or more and 5 mm or less, and in the case where the effective diagonal length is 0.7 inch, the diameter is 4 mm or more and 10 mm or less.
[0252]
Note that the diameter refers to a region area where the Fresnel lens 552 can collect light and irradiate the liquid crystal display panel 1333. Therefore, even if the diameter is large, if the Fresnel lens 552 cannot collect light, the diameter is effectively regarded as small.
[0253]
  Reference examples related to the present inventionWhen a PD liquid crystal display panel is used for the viewfinder, a pinhole plate should be disposed in front of the lamp 11. Of course, when the light emitting area of the lamp 11 is very small, it goes without saying that the pinhole plate is not necessary.
[0254]
The pinhole plate has a function of reducing a region where light is radiated from the lamp 11 into a small region. When the hole area increases, the display image of the PD liquid crystal display panel becomes brighter, but the contrast decreases. This is because the amount of light incident on the Fresnel lens 552 increases, but the directivity of incident light deteriorates. For example, when the diagonal length of the display area of the liquid crystal display panel 1333 is 28 mm (1.1 inches), the area that emits light is approximately 15 mm.²Should be: This corresponds to the diameter of a pinhole having a diameter of approximately 4 mm. Preferably 10mm²Should be:
[0255]
However, if the diameter of the hole is made too small, the directivity of light becomes unnecessarily narrow, and when the viewfinder is viewed, the display screen becomes extremely dark just by slightly shifting the viewpoint. Therefore, the hole area is at least 2 mm²The above areas should be secured. As an example, when the hole has a straight line of 3 mm, the brightness of the display screen is equal to or higher than that of a viewfinder using a conventional surface light source, and the contrast at that time is 20 or more.
[0256]
The region that emits light, i.e., the hole, should be considered in the range of 1 mm to 5 mm in diameter. If it is defined by the ratio of the display area to the area of the hole that emits light, it must be 20: 1 or less. Preferably it is 40: 1 or less. However, it is preferably 200: 1 or more from the viewpoint of viewing angle. The above isReference examples related to the present inventionThe same applies to other viewfinders.
[0257]
The matters relating to the filament 24 of the lamp 11 are arranged so that the A-side faces the display panel 1333 as shown in FIG.
[0258]
A reflector 831 is disposed on the rear surface of the lamp 11. This is because the light emitted backward in the viewfinder is wasted. By disposing the reflecting means (reflecting plate 831) on the rear surface of the lamp 11, the amount of luminous flux radiated from the front surface is increased, and the lamp 11 can be increased in luminance.
[0259]
FIG. 41 shows an example of optical design in the case where the Fresnel lens 552 is an aspherical lens and the diffuser plate 15 is not provided.
[0260]
Examples of the reflecting plate 831 include a processed aluminum plate and stainless steel plate. Moreover, what vapor-deposited thin films, such as aluminum, on the back surfaces, such as glass, may be used. 90, the reflecting plate 831 may be disposed so as to be in close contact with the lamp 11, and a transparent adhesive 381 or the like may be filled between the lamp 11 and the reflecting plate 831. The transparent adhesive 381 fixes the reflector 831 and the lamp 11 as a single unit to facilitate mounting on the body 1321, reduces the loss due to interface reflection between the reflector 831 and the lamp 11, and is emitted to the front. It has a function to increase the amount of light.
[0261]
Further, as shown in FIGS. 83 (b) and 90, the apex of the lamp 11 is a plane. This is because the reflector 831 can be easily attached to the lamp 11 (if the apex is spherical, it is difficult to attach), and the luminous flux at the apex part is reflected and guided to the front of the lamp effectively. . Of course, the reflector 831 and the lamp 11 may be arranged as shown in FIG.
[0262]
By configuring the lamp portion as shown in FIG. 83 (b) above, the light flux at the rear and apex portions of the lamp 11 can be effectively guided to the side surface of the lamp, and the light emission luminance toward the front surface can be increased. According to the experiment, when the reflection plate 831 is present, the luminance is improved by about 30% or more compared with the case where the reflection plate 831 is not present, and the luminance unevenness on the front surface is also greatly reduced.
[0263]
Note that the color temperature of the lamp 11 can be adjusted if one color of the reflector 831 can be favorably reflected. For example, if the reflector 831 strongly reflects red, the color temperature of the lamp 11 is lowered. On the other hand, if blue is strongly reflected, the color temperature increases. As a realization means, a pigment and a dye may be added to the adhesive 381. Moreover, it corresponds when the reflecting plate 831 itself is colored. For example, red aluminum foil.
[0264]
The light emitted from the lamp 11 uniformly illuminates the effective display area of the liquid crystal display panel 1333 by the Fresnel lens 552. However, it is better that the illumination range is slightly wider than the effective display area diameter. This is because when the display image of the display panel 1333 is viewed from the magnifying lens 1336, the four corners of the panel are prevented from becoming dark even if the viewing angle is slightly changed.
[0265]
The light emitting area of the lamp 11 is set near the focal point of the condenser lens 522. When the focal point f of the lens is the surface of the light emitting region of the lamp 11 as shown in FIG. 58A, the focal point of the lens is the rear end of the lamp 11 as shown in FIG. In this case, as shown in FIG. 58C, the case where the focus of the lens is a defocused position is included. According to the experiment, in the state of FIG. 58B, the distance d from the top of the condenser lens 552 to the rear end of the lamp 11 is shortened, and the light emitting area of the light emitting element (lamp 11) viewed from the condenser lens 552. Therefore, the viewing angle of the viewfinder becomes wide, which is preferable. When the diameter of the lamp 11 was 5.1 mm and the liquid crystal display panel 1333 was 0.5 inch, d was around 12 mm, and when d was 0.7 inch, around 17 mm was appropriate.
[0266]
When the liquid crystal display panel 1333 is a TN liquid crystal display panel, the display contrast is improved when the directivity of light incident on the liquid crystal display panel 1333 is narrow. This is because the analyzer 1334b (see FIG. 23) is the most when the orientation direction of liquid crystal molecules in the liquid crystal layer of the liquid crystal display panel 1333 (when a voltage is applied to the liquid crystal layer) matches the direction of incident light. This is because less light is transmitted.
[0267]
A conventional viewfinder includes a surface light source, and light from the surface light source enters the liquid crystal display panel 1333. The light from the surface light source is scattered light (light having no directivity). Therefore, the alignment direction of liquid crystal molecules (when a voltage is applied to the liquid crystal layer) of the liquid crystal display panel 1333 does not match the direction of incident light. Therefore, the amount of light that passes through the analyzer 1334b increases and the display contrast deteriorates.
[0268]
on the other hand,Reference examples related to the present inventionIn a viewfinder or the like, light emitted from the light emitting element (lamp 11) is converted into light having a narrow directivity by using a condensing means (Fresnel lens 522 or reflector 831 or the like). Accordingly, light with narrow directivity is incident on the liquid crystal display panel 1333. Therefore, the alignment direction of liquid crystal molecules (when a voltage is applied to the liquid crystal layer) and the direction of incident light coincide with each other, and the display contrast is improved. This is the same even when a PD liquid crystal display panel is used as the light modulation means. That is, the PD liquid crystal display panel does not use the analyzer 1334b, but the light transmittance is obtained when the liquid crystal molecules in the water droplet-like liquid crystal 245 (see FIG. 24) are aligned in one direction and the aligned direction and the direction of incident light coincide. This is because it is the same in that the display contrast is improved by improving. This is another example shown in FIG.Reference examples related to the present inventionThe same applies to the viewfinder.
[0269]
In FIG. 83 and the like, the pitch of the Fresnel lens 552 is very wide, but this is for ease of illustration, and it is usually formed at a very short pitch of at least 1 mm or less. is there.
[0270]
A diffusion plate 15 is disposed on the light exit surface of the Fresnel lens 552 as a light scattering means. Examples of the diffusing plate 15 include those formed by combining special glass fibers and polycarbonate resin that are sold by Plastics Co., Ltd. (for example, ECB1020, ECB1010). However, this seems to be a little too diffuse. The light-up series MX100, SX100, SH100, etc. of Kimoto Corporation are appropriate. The diffuser plate 15 having a total light transmittance (%) of 80% or more is used. If the total light transmittance is poor, less light reaches the liquid crystal display panel 1333 and the display screen is darkened, resulting in an increase in power consumption of the light source. However, if the total light transmittance (%) is high, the groove of the Fresnel lens 552 can be seen through the liquid crystal display panel 1333.
[0271]
  Reference examples related to the present inventionIt may be argued that the diffusion plate 15 used in the viewfinder or the like is not the same as the diffusion plate of the conventional viewfinder. However, the configuration, purpose, and effect are completely different as described below.
[0272]
As shown in FIG. 138, the conventional viewfinder forms a surface light source by scattering light from the fluorescent tube by the diffusion plate 15a. The surface light source means that the light beam is ideally emitted in all directions and the luminance is almost the same (completely diffusing surface) even if the luminance is measured from any direction. The reason why the light emission pattern of the fluorescent tube is visible as shown in FIG. 138 is that there are many light beams traveling straight through the diffusion plate 15a. This is because the surface light source is incomplete, and the diffusion plate 15a is ideally for obtaining a complete diffusion surface. Accordingly, scattered light is incident on the liquid crystal display panel 1333.
[0273]
Compared to this, it is described in the column of this embodiment.Reference examples related to the present inventionA viewfinder or the like converts light from the lamp 11 into substantially parallel light (light having a narrow directivity) by a condensing means (illumination lens, Fresnel lens 552), and the converted light passes through a diffusion sheet (plate) 15. Thus, the light is incident on the liquid crystal display panel 1333. The diffusion sheet (plate) 15 is not intended to form a surface light source. This is used to slightly widen the directivity of light because the pixels of the liquid crystal display panel 1333 interfere with the grooves of the Fresnel lens 552 to generate moire. Further, the groove of the Fresnel lens 552 that is slightly visible through the magnifying lens 1336 or the like is made difficult to see. Accordingly, light having a narrow directivity mainly enters the liquid crystal display panel 1333. In other words, light with narrow directivity is dominant.In reference examples related to the present invention,Light slightly scattered by the diffusion plate 15 incidentally enters the liquid crystal display panel 1333.
[0274]
From the above, even though the diffuser plate 15 and the diffuser plate 15a have the same function of “scattering” light, they basically differ in “whether or not they form a surface light source”. Further, the conventional viewfinder has a non-directional light incident on the liquid crystal display panel 1333.Reference examples related to the present inventionA viewfinder or the like basically differs in that light having narrow directivity is converted into light having a narrow directivity by a light collecting means (condenser lens, Fresnel lens 552) and incident on the liquid crystal display panel 1333.
[0275]
There is a possibility that light interferes with the pixel pitch Pd of the liquid crystal display panel 1333 and the pixel pitch Pr of the Fresnel lens 552, and moire occurs.
[0276]
By disposing the diffusion plate 15 between the Fresnel lens 552 and the liquid crystal display panel 1333, it is possible to make it difficult to see even if moire occurs. The pitch P of the generated moire is
[0277]
[Expression 1]

[0278]
It can be expressed. The maximum moire pitch is the smallest
[0279]
[Expression 2]

[0280]
In this case, the greater the n, the smaller the degree of moire modulation. Therefore, Pr / Pd may be determined so as to satisfy (Equation 2). However, since the Fresnel lens 552 has concentric grooves and the pixels of the liquid crystal display panel 1333 are arranged in a matrix, it is somewhat difficult to determine the pitches Pr and Pd in (Equation 2). However, a value that can reduce the occurrence of moire can be derived by experimentation in consideration of (Equation 2).
[0281]
In (Expression 2), n is an integer value. The pixel pitch Pd is a constant value because it is determined by the pixel size of the liquid crystal display panel 1333 and the like. Therefore, it is necessary to set the pitch Pr of the Fresnel lens 552 to an optimum value in consideration of the production of the Fresnel lens 552. Since n is an integer value, Pr is a quantum value. At the time of manufacturing the Fresnel lens 552, it is difficult to determine the value of Pr in accordance with the above formula due to problems in accuracy and processing. Therefore, the value of Pr is slightly deviated from the ideal value. In practice, there is no problem even if it is somewhat distant. As a guide, it may be within ± 20%, preferably within ± 10%.
[0282]
The Fresnel lens 552 is obtained by processing acrylic or polycarbonate resin. As an example, those sold by Koyo Co., Ltd. can be employed. The Fresnel lens 552 can be manufactured using a machine tool when the amount is small, but it is easier to manufacture using a mold when manufacturing a large amount, and the cost can be reduced. The Fresnel lens 552 is flat on the lamp 11 side, but the reflectance is lowered, and this is because the amount of light incident on the Fresnel lens 552 is increased. This is also to satisfy the sine condition.
[0283]
In FIG. 83, the condensing unit is configured by using one Fresnel lens 552, but it is needless to say that the condensing unit may be configured by using a plurality of Fresnel lenses 552. Further, the Fresnel lens 552 and the plano-convex lens may be combined. Moreover, the structure of FIG. 60 may be sufficient. FIG. 59A shows a configuration in which the light incident surface of the Fresnel lens 552a is a concave surface. By forming the concave surface in this way, the angle of the light incident on the lens becomes relatively small, and the reflected light is reduced.
[0284]
In addition,Reference examples related to the present inventionIn the description of the viewfinder, it is assumed that substantially parallel light is incident on the liquid crystal display panel 1333. However, the present invention is not limited to this. For example, in the case of the light beam 51b in FIG. 57, the principal light beam incident on the liquid crystal display panel 1333 is slanted, but even if it is slightly slanted, there is no problem in practical use.
[0285]
Since the groove of the Fresnel lens 552 can be seen through the magnifying lens 1336, the diffusion plate 15 is disposed between the liquid crystal display panel 1333 and the Fresnel lens 552. However, the center portion of the Fresnel lens 552 is particularly likely to be seen (the region indicated by 921 in FIG. 92). The outer periphery of the Fresnel lens 552 is hardly visible. Therefore, as shown in FIG. 92B, a diffusion portion 921 is formed at the center of the Fresnel lens 552. Specifically, the diffusing portion 921 corresponds to a diffusing plate 15 that has been made small. In addition, it is also effective to apply the technical idea of FIG. 34 to the diffusion plate 15.
[0286]
Note that the diffusion plate 15 is an optical low-pass filter and has a concept including a diffraction grating, a prism sheet, a microlens array, a cell hook lens array, and the like in addition to the diffusion plate described above. Furthermore, a method using the concept of MTF shown below without using a low-pass filter such as a diffusion plate is also included.
[0287]
The diffuser plate 15 deteriorates the directivity of the light emitted from the light condensing means (Fresnel lens, light condensing lens 522), and lowers the display brightness of the liquid crystal display panel 1333. Therefore, MTF (Modulation Transmission Function) may be considered as one method for eliminating the diffusion plate 15. The explanation is shown in FIG. Normally, the magnifying lens 1336 is focused on the light modulation layer of the liquid crystal display panel 1333 (focus adjustment is performed so that a virtual image of the light modulation layer can be satisfactorily seen. Or, the observer is in focus. The position of the magnifying lens 1336 is adjusted as described above). Here, the focus position (distance) is assumed to be f. If the distance between the magnifying lens 1336 and the Fresnel lens 552 is f, the groove of the Fresnel lens 552 is in focus. Conversely, as the distance between the magnifying lens 1336 and the Fresnel lens 552 is different from f, the groove of the Fresnel lens 552 becomes out of focus and becomes invisible to the observer.
[0288]
In the optical field, MTF is used as a comparison for imaging. For example, the expression is a little rough, but when the MTF is 100%, it is in focus at an infinite resolution. The smaller the MTF, the more out of focus. As shown in FIG. 94, various MTFs can be created depending on the configuration and design of the optical system. In FIG. 94, a distance of 0 means that the distance from the magnifying lens 1336 to the modulation layer of the liquid crystal display panel 1333 is f (in focus). The resolution deteriorates the more you deviate from it.
[0289]
According to the optical design, it is possible to realize a configuration in which the MTF deteriorates abruptly (dotted line in FIG. 94) when it slightly deviates from the in-focus point, and a configuration in which the MTF does not deteriorate (solid line in FIG. 94).Reference examples related to the present inventionThe viewfinder preferably has the dotted line configuration of FIG.
[0290]
That is, the Fresnel lens 552 is placed at a position where the MTF is 20% or less. In the case of the solid line, if the point where the MTF is 20% or less is X2, the total length of the viewfinder becomes long. Preferably, the Fresnel lens 552 is disposed at a position where the MTF is 10% or less.
[0291]
If the Fresnel lens 552 is arranged at a position where the MTF is lowered as described above, the MTF (resolution) of the groove of the Fresnel lens 552 is lowered and the groove becomes invisible, so that the diffusion plate 15 is not necessary. Further, the fact that the groove of the Fresnel lens 552 becomes invisible means that the periodicity is lost when the light passing through the groove position reaches the liquid crystal display panel, and therefore, moire is less likely to occur.
[0292]
As an exampleReference examples related to the present inventionThe diameter of the Fresnel lens 552 used in the viewfinder is 20 mm, and the focal length is 22 mm. As the focal distance d becomes shorter, the distance d between the light emitting element (lamp 11) and the Fresnel lens 552 can be shortened and the viewfinder can be made compact, but the light condensing efficiency of the Fresnel lens 552 is lowered. Conversely, if the focal length d is too long, the light condensing efficiency is improved, but the total length of the viewfinder becomes too long. In that case, two Fresnel lenses should be used. Then, the focal length can be shortened.
[0293]
The focal length d of the Fresnel lens 552 is determined according to the diagonal length dp of the effective display area of the liquid crystal display panel 1333. The focal length is 0.6 to 2.0 times dp, more preferably 0.8 to 1.5 times dp.
[0294]
The viewfinder should have a certain length (full length) from the viewpoint of ease of use, but it is desirable that the viewfinder be as short as possible (compact). Therefore, in this embodiment, the distance d2 between the liquid crystal display panel 1333 and the Fresnel lens 552 and the distance d1 between the Fresnel lens 552 and the lamp 11 can be contracted. Therefore, the Fresnel lens 552 is attached to the body 1321b, and the lamp 11 and the like are attached to the body 1321c. FIG. 84 is a configuration diagram when contracted. 83. A spring or the like (not shown) is arranged between A and B in FIG. 83, and the extended state in FIG. 83 and the contracted state in FIG. 84 can be switched. In particular, since the Fresnel lens 552 is planar, it is easy to contract.
[0295]
83, both d1 and d2 can be shrunk, but it goes without saying that even if only one of them can be shrunk as shown in FIG. 81, it can contribute to downsizing when carried. The concave lens 1336b is a lens for aberration and color correction, and is preferably applied to the viewfinder having the configuration shown in FIG. The concave lens 1336b may be a convex lens.
[0296]
Since the position of the observer's pupil is almost fixed by the eyepiece cover 1332 in the viewfinder, the light source disposed behind the viewfinder may have a narrow directivity. In a conventional viewfinder that uses a light box 1331 (FIG. 137) using a fluorescent tube as a light source, only light traveling from a region having the same size as the display region of the liquid crystal display panel 1333 to a small solid angle in a certain direction is used. The light traveling in the other direction is not used. That is, the light utilization efficiency is very poor.
[0297]
In the present embodiment, a light source 11 having a small illuminant is used, and light emitted from the illuminant to a wide solid angle is converted into light almost parallel by a Fresnel lens 552 or the like. In this way, the directivity of the light emitted from the Fresnel lens 552 or the like becomes narrower. If the observer's viewpoint is fixed, the narrow directional light described above is sufficient for the use of the viewfinder. Naturally, if the size of the light emitter is small, the power consumption is small. As described above, the viewfinder of the present embodiment utilizes the fact that the observer views the display image with the viewpoint fixed.
[0298]
FIG. 85 shows a configuration in which the viewfinder of FIG. 83 is attached to the video camera main body 431. When the viewfinder is used, it is stored in the video camera main body 431 while being contracted by the fastener 851 (protrusion) (see FIG. 85A). When the viewfinder is used, the fixing with the fastener 851 is removed, and the A and B portions shown in FIG. 83 are extended, and the liquid crystal display panel 1333 is appropriately irradiated with the parallel light by the lamp 11.
[0299]
However, if there is no contraction mechanism between the Fresnel lens 552 and the lamp 11 as shown in FIG. 83, the distance d1 cannot be shortened and the entire length of the viewfinder becomes long. In that case, a mirror 751 may be disposed between the lamp 11 and the Fresnel lens 552 as shown in FIG. If the protruding portion (insertion portion 811) in FIG. 81 is designed or configured to be inserted into the video camera main body 431 having the imaging lens 432, there is no obstacle (see FIG. 81 (b)). That is, it is possible to freely rotate the insertion portion 811 in the direction of viewing by the observer (see the dotted line in FIG. 81 (b)).
[0300]
The TN liquid crystal display panel 1333 requires a polarizing plate 1334 to perform light modulation. In order to obtain an optimum display contrast, it is necessary to adjust the polarization axis angles of the polarizer 1334a and the analyzer 1334b. The angle is related to the voltage applied to the liquid crystal layer of the liquid crystal display panel 1333, and it is often necessary to adjust the angle according to the characteristics of the individual liquid crystal display panel. As shown in FIG. 82, the knob 821 is connected to the Fresnel lens 552. That is, by moving the 821 up and down, the Fresnel lens 552 rotates and the polarization axis of the polarizer 1334a also rotates. Therefore, the polarization axis can be easily adjusted according to the characteristics of the individual liquid crystal display panel 1333.
[0301]
The configuration of FIG. 81 is a configuration that facilitates the adjustment. A polarizer 1334 a is attached to the Fresnel lens 552. The polarizer 1334a is configured to be rotatable about the lens center. That is, by rotating the Fresnel lens 522, the polarization axis of the polarizer 1334a is also rotated, and the angle between the polarization axis of the polarizer 1334a and the polarization axis of the analyzer 1334b can be adjusted. By adjusting the angle, adjustment is made to a position where the image on the display panel 1333 looks best.
[0302]
A part of the light emitted from the lamp 11 is reflected by the Fresnel lens 552 and the like, and becomes stray light. In order to prevent the stray light, an antireflection film may be formed on the Fresnel lens 552 or the like. However, even if an antireflection film is formed, the generation of stray light cannot be completely prevented.
[0303]
The stray light becomes a factor that reduces the contrast of the display image. In order to avoid this problem, a circular stop 931 may be arranged between the lamp 11 and the Fresnel lens 552 as shown in FIG. The circular diaphragm 931 has a circular window at the center, and a plurality of diaphragms are arranged concentrically at predetermined intervals. The circular diaphragm 931 allows light emitted from the lamp 11 to pass only light that directly enters the effective area of the Fresnel lens 552. The inner surfaces of the body 1321 and the eyepiece ring 1335 are black or dark in order to prevent light reflection. Of the light emitted from the lamp 11, unnecessary light is absorbed by the light shielding portion of the circular diaphragm 931, and light that is slightly reflected without being absorbed is absorbed by the light shielding portion of the other diaphragm or the inner surface of the body 1321. Therefore, it does not enter the Fresnel lens 552. Therefore, the contrast reduction of the display image due to the unnecessary light incident on the liquid crystal display panel 1333 becomes very small. One aperture may be used, but the effect increases as the number increases.
[0304]
The liquid crystal display panel 1333 usually has a black matrix (not shown). The black matrix is used to obscure the movement of the liquid crystal on the signal line of the liquid crystal display panel 1333 or / and to block light to the thin film transistor that switches the pixels. However, when the number of pixels of the liquid crystal display panel 1333 is small, the black matrix is conspicuous and the image quality is lowered.
[0305]
Therefore, as shown in FIG. 93, if a diffraction grating 932 is disposed as an optical low-pass filter between the liquid crystal display panel 1333 and the pupil of the observer, the black matrix can be made inconspicuous. The diffraction grating 932 is disposed between the magnifying lens 1336 and the liquid crystal display panel 1333. Further, it may be arranged on the incident light side of the liquid crystal display panel 1333. However, it goes without saying that the pitch and height of the diffraction grating 932 need to be changed depending on the arrangement position. The diffraction grating 932 has an effect of making the black matrix difficult to see. Therefore, a smooth display image can be obtained without the black matrix being seen.
[0306]
The diffraction grating 932 is a transmission type, and the cross-sectional shape of the grating may be a sine curve, arc, trapezoid, or the like. Many variations such as one-dimensional and two-dimensional patterns can be considered for the diffraction grating 932. In addition, when the pixel size of the liquid crystal display panel 1333 is 100 to 30 μm and the diffraction grating 932 is disposed near the liquid crystal display panel 1333, the pitch is suitably in the range of 100 to 20 μm.
[0307]
When the diffraction grating 932 is disposed near the magnifying lens 1336, 2 to 0.1 mm is appropriate. As a method of manufacturing the diffraction grating 932, a method of depositing an inorganic substance such as SiO2 on a glass substrate and patterning, a mixture of a polymer and a dopant is spin-coated on the glass substrate, exposed through a pattern mask, and then reduced in pressure. There is a method of sublimating the dopant by heating. Kuraray Co., Ltd. manufactures and sells diffraction grating plates.
[0308]
Further, the diffusion plate 15 may be attached to the liquid crystal display panel 1333 as shown in FIG. As the contraction mechanism, the entire length of the viewfinder can be contracted and expanded as shown in FIGS. 99 and 100 by attaching the liquid crystal display panel 1333 to the mounting holder 991 and attaching the lamp 11 to the body 1321.
[0309]
As a problem of the Fresnel lens 552, there is interface reflection occurring in the Fresnel lens 552 as shown in FIG. In particular, when incident light 872 is incident on the interface 1022 of the Fresnel lens 552, it is reflected at the interfaces 1024, 1023, etc. as indicated by the dotted lines in the figure. As a countermeasure, there is a method of increasing the thickness t of the Fresnel lens 552 as shown in FIG. If it is physically difficult to increase the thickness of the Fresnel lens 552, the transparent substrate 1011 may be attached to the Fresnel lens 552 with a transparent resin 901. A light absorbing film 1012 is applied to a side surface of the transparent substrate or the like (outside the effective display range, where light is not directly incident). Examples of the light absorbing film 1012 include black paint.
[0310]
By increasing the apparent thickness of the Fresnel lens 552 as described above, the light beam 872 is once reflected at the interface 1031 and is incident on the black paint 1012 on the side surface as shown in FIG. 103, so that no halation occurs in the Fresnel lens 552. In FIG. 101, if the relationship between t and d is d / 8 <t, halation hardly occurs and a satisfactory result was obtained.
[0311]
If the PD liquid crystal display panel 1041 is used instead of the diffusion plate 15, the degree of diffusion can be freely changed. An explanation of this configuration is shown in FIG.
[0312]
First, a PD liquid crystal display panel 1041 used instead of the diffusion plate 15 will be described. As described above, the PD liquid crystal display panel 1041 operates on the operation principle of FIG. An ITO electrode 1046 is formed on the glass substrate 1045, and a PD liquid crystal layer 1047 is sandwiched between the ITO electrodes 1046. Reference numeral 1044 denotes a sealing resin. When no voltage is applied to the ITO electrode 1046, the liquid crystal layer 1047 is in a scattering state, and when a voltage is applied, the PD liquid crystal layer 1047 is in a transparent state. The degree of diffusion of the PD liquid crystal layer 1047 changes depending on the strength of the voltage.
[0313]
The signal generation source 1042 outputs a rectangular wave, and the rectangular wave changes the signal amplitude by a signal amplitude variable device 1043. The signal amplitude is changed by the resistor Rb. The larger the size of the rectangular wave, the more transparent the PD liquid crystal layer 1047 is.
[0314]
The light 51 emitted from the lamp 11 is collected by the Fresnel lens 552. The straightness of the light is changed by the PD liquid crystal display panel 1041. Accordingly, the PD liquid crystal display panel 1041 has an effect of making it difficult to see the groove of the Fresnel lens 552 as in the case of the diffusion plate 15. Further, since the light transmittance is changed, the display luminance of the display panel 1333 can be adjusted.
[0315]
When the transmittance of the PD liquid crystal display panel 1041 is high, the liquid crystal display panel 1333 can perform high luminance display. Therefore, it is suitable for viewing a display image in a bright place. Conversely, when the transmittance of the PD liquid crystal display panel 1041 is low, the display image on the liquid crystal display panel 1333 becomes dark. However, since the viewing angle is wide, it is suitable for viewing the liquid crystal display panel 1333 from a wide range. As described above, the display state of the liquid crystal display panel 1333 can be adjusted according to the situation.
[0316]
In order to prevent light reflection by the interface, the diffuser plate 15 and the Fresnel lens 552 may be attached with an optical binder as shown in FIG. Light transmittance is increased and halation at the interface is also reduced. Needless to say, the PD liquid crystal display panel 1041 may be used instead of the diffusion plate 15 as shown in FIG. Of course, as shown in FIG. 106, both the diffusion plate 15 and the PD liquid crystal display panel 1041 may be used.
[0317]
As described above, it goes without saying that the function as a diffusion plate can be achieved even if a diffraction grating 932 is used instead of the diffusion plate 15 as shown in FIG. In order to change the radiation area of light from the lamp 11, a diaphragm 1091 is provided as shown in FIG. Examples of the aperture 1091 include those used for camera shutter rainbow sampling aperture and aperture. As the hole diameter of the aperture 1091 is reduced, the directivity is narrowed and the display contrast of the liquid crystal display panel 1333 is improved. On the other hand, if it is increased, the directivity becomes wider and the display contrast of the liquid crystal display panel 1333 is lowered, but the display image becomes brighter.
[0318]
  Reference examples related to the present inventionThe configuration of the viewfinder has been described as having the magnifying lens 1336, but is not limited thereto. For example, the magnifying lens 1336 may not be provided as shown in FIG. In this case, the display image that the observer can see becomes small, but there is no practical problem when the size of the liquid crystal display panel 1333 is larger than a certain value (1 inch or more is easy to see).
[0319]
Although the Fresnel lens 552 and the like have been described as a transmission type, it is needless to say that a reflection type can be configured as shown in FIG. A reflective Fresnel lens 1211 can be manufactured by processing an aluminum plate or the like. It can also be produced by molding with a glass resin and depositing a metal thin film such as Al on the surface. The Fresnel lens 1211 collects the light reflected from the lamp 11 and the reflection plate 883 to illuminate the liquid crystal display panel 1333 as substantially parallel light.
[0320]
As shown in FIG. 111, the light from the lamp 11 can be applied to the light collecting means (Fresnel lens, illumination lens 552, etc.) using a light guide 1111. If the light guide 1111 is used in this manner, the arrangement position of the lamp 11 is not restricted. Therefore, the lamp 11 can be placed in a small space and the space can be used effectively.
[0321]
As shown in FIG. 112, a reflective film 1121 such as Al is formed on the outer surface of the light guide 1111, and the light guide 1111 is covered with the lamp 11. The light emitted from the lamp 11 is transmitted through the light guide 1111 while being reflected between the reflection films 1121 and is emitted from the emission end.
[0322]
In FIG. 112, the lamp 11 is covered with the light guide 1111. However, the present invention is not limited to this, and the lamp 11 may be attached to the tip of the lamp 11 with an adhesive 1051 as shown in FIG. Further, as shown in FIG. 113B, a spring having a plurality of optical fibers 1131 may be used as the light guide.
[0323]
FIG. 114 shows a method of illuminating the liquid crystal display panel 1333 using external light (sunlight 1141 or the like) particularly when using outdoors. A window is opened at the top of the viewfinder body 1321 and a Fresnel lens 1143 is fitted. The Fresnel lens 1143 is used to reduce the lens thickness, and may be replaced with a positive lens made of plastic or glass when allowed. Since the sunlight 1141 is substantially parallel light, the light is collected by the Fresnel lens 1143, reflected by the mirror 751, the light traveling direction is bent, and enters the light collecting means 552.
[0324]
That is, the Fresnel lens 552 has a function of condensing both the outdoor light 1141 and the light from the lamp 11.
[0325]
The state of the light reflected by the mirror 751 is arranged at a position where the same state as the light emitted from the lamp 11 is obtained. Needless to say, when the outdoor light 1141 is not taken into the body 1321 and the liquid crystal display panel 1333 is illuminated, the lamp 11 is caused to emit light and the light from the lamp 11 is used.
[0326]
When the lamp 11 is made to emit light or the outdoor light 1141 is weak, the lamp 11 is made to emit light so that the amount of light flux (luminance) per unit area incident on the display panel 1333 is set to a constant value. The lamp 11 is turned on, or the brightness of the light emission luminance is determined by determining the intensity of the outdoor light 1141 with the photo sensor 1142 disposed on the top of the body 1321 or the like. FIG. 115 shows a circuit configuration for the determination. The photo sensor 1142 corresponds to a photodiode or the like.
[0327]
The photodetection circuit 1152 includes a photosensor 1142 and an operational amplifier A.₁It is composed of an integration circuit consisting of, etc. Operational amplifier A₁Outputs a voltage V according to the intensity of the outdoor light 1141. Reference numeral 1151 denotes a hysteresis comparator circuit, which is a resistor R that determines the hysteresis state.₂, R_ThreeAnd operational amplifier A₂And reference voltage V_FiveIt is comprised from the voltage source which produces | generates.
[0328]
Operational amplifier A₁Output voltage V is the reference voltage V_FiveCompared with Operational amplifier A when V is above a certain value₂The voltage at the output terminal a becomes a + voltage (or-voltage). The contact of the analog switch SW1153 is closed by the voltage, and the voltage E_aIs applied to the anode electrode 25 and the lamp 11 is turned on. Op amp A₂The analog switch SW1153 is open at the point where the output of − is (−) voltage (or + voltage).
[0329]
The reason why the hysteresis comparator circuit 1151 is used is to cope with the intensity of light 1141 input to the photosensor 1142 (for example, when the sun falls into the shadow of a cloud while using a video camera). Comparator A each time depending on the intensity of external light₂This is because the lamp 11 blinks and the display image on the liquid crystal display panel 1333 is very difficult to see. By using the hysteresis comparator circuit 1151, once the lamp 11 is turned on, it is not turned off even if the outdoor light 1141a becomes somewhat strong. Therefore, it will not blink.
[0330]
FIG. 117 is a viewfinder configuration diagram using a liquid crystal display panel 1333 having a larger display screen than FIG. The lamp 11 is placed horizontally to shorten the overall length of the viewfinder. In order to facilitate understanding, the light shielding cover 1171 and the liquid crystal display panel 1333 are shown apart from each other, but they are arranged in close contact with each other. The light shielding cover 1171 is used to define the viewing direction of the observer. When the observer tries to view the liquid crystal display panel 1333 from an oblique direction, the light shielding cover 1171 makes the peripheral portion of the display screen of the liquid crystal display panel 1333 invisible.
[0331]
Therefore, the observer tries to view the display image on the liquid crystal display panel 1333 from the front of the screen. The eyepiece cover 1333 is arranged in this way because light emitted from the lamp 11 is converted into light having a narrow directivity by the Fresnel lens 552 (or a condensing lens), and an observer views the light having a narrow directivity. Because it becomes. Since the directivity is narrow, the image suddenly appears dark except in front of the liquid crystal display panel 1333. Therefore, the light shielding cover 1171 is arranged to guide the observer to see the display image from the direction in which it looks bright.
[0332]
However, the viewing angle is expanded by arranging the diffusion plate 15. The higher the diffusivity of the diffusing plate 15 is, the wider the viewing angle (the angle until the display image becomes invisible depending on the viewing angle). However, the display image becomes dark and the display contrast also decreases. Therefore, the diffusion degree of the diffusion plate 15 is made as low as possible. Therefore, the angle at which the display image can be viewed satisfactorily is defined using the light shielding cover 1171. With this configuration, the light emitted from the light source can be used effectively and the power consumption can be reduced.
[0333]
When the effective display area of the liquid crystal display panel 1333 is large, or when the focal length of the Fresnel lens 552 is long, the total length may be long. Therefore, as shown in FIG. 118, the optical path 872 is bent using a mirror 751. What is necessary is just to comprise. The light emitted from the lamp 11 is bent at an angle by the mirror 751 b and enters the Fresnel lens 552.
[0334]
In FIG. 117, the light emitting element (lamp 11) is illustrated as using a small fluorescent discharge tube 11. However, the light emitting element may be a small fluorescent tube 882 or the like as shown in FIG. As the small fluorescent tube 882, there are product numbers K-C21T26E85H and K-C30T26E85H manufactured by Matsushita Electric Industrial Co., Ltd. These fluorescent tubes are of a cold cathode type and have low lamp power consumption of 0.33 W and 0.4 W.
[0335]
A semi-cylindrical reflector 883 is disposed on the back of the fluorescent tube 882 so that the light emitted from the fluorescent tube 882 can be effectively emitted to the front. Further, a flat cylindrical lens 881 is disposed in order to condense light from the fluorescent tube 882 well. This is because the light emitting means is a rod-shaped light emitter, and therefore it is not necessary to be a concentric Fresnel lens 552, and a cylindrical lens 881 may be used.
[0336]
Light emitted from the front surface of the fluorescent tube 882 directly enters the cylindrical lens 881, is condensed, and enters the liquid crystal display panel 1333. The light emitted from the rear surface of the fluorescent tube 882 is reflected by the reflecting plate 833, then enters the cylindrical lens 881, and enters the liquid crystal display panel 1333. Of course, a light shielding cover 1171 may be arranged as shown in FIG.
[0337]
In FIG. 83, the distance d2 between the liquid crystal display panel 1333 and the Fresnel lens 552 is configured to be extended when used. The same thing can be implemented with the configuration of FIG. As shown in FIG. 87, a case 861 to which a liquid crystal display panel 1333b is attached and a case 871 to which a lamp 11 is attached are coupled by a bellows 862b, and the bellows 862b is expanded and contracted to adjust between the display panel 1333 and the Fresnel lens 552. You can do it.
[0338]
In the configuration of FIG. 87, since the liquid crystal display panel 1333 is large, a certain distance is required between the lamp 11 and the condenser lens 552, and thus the volume is large. In order to solve this, the configuration shown in FIG. When the viewfinder is not used, the bellows 862a is folded as shown in FIG. When in use, as shown in FIG. 86B, the bellows 862a and 862b are extended so that the light emitting portion of the lamp 11 comes to the focal position of the condenser lens 552.
[0339]
The liquid crystal display panel 1333, the diffusion plate 15, and the condenser lens 552 are fixed integrally with each other via a bellows 862. The bellows 862 is used to prevent external light from entering and for contraction, but is not limited thereto. For example, as shown in FIG. 83, it may be a telescopic cylinder (1321b).
[0340]
It is easy for the observer to adjust the display image on the liquid crystal display panel 1333 so that the image can be easily seen. Screws are fixed to the rotary shaft 863 so as to be rotatable, and can be freely rotated and fixed as indicated by dotted lines and solid lines in FIG. This is particularly effective when used as a video camera monitor. This is because it is necessary to change the viewing position of the viewfinder in order to photograph (capture) a subject satisfactorily with a video camera.
[0341]
In order to effectively use the light radiated from the apex or side surface of the lamp 11, a configuration as shown in FIG. Light 872 emitted from the apex of the lamp 11 is reflected by the mirror 883a and travels toward the display panel 1333 as light 872d in FIG. Of course, the light 872 radiated from the front face goes straight to the display panel 1333. The light emitted from the side surface of the lamp 11 is reflected by the mirrors 883c and 883b and enters the display panel 1333 as shown in FIG.
[0342]
As shown in FIG. 120, when the light from the oblique direction is incident on the display panel 1333 using the mirror 883, the viewing angle when the observer views the display image on the display panel 1333 is widened. That is, the display image does not suddenly become dark even if the eye position is slightly shifted.
[0343]
As shown in FIG. 123, a plurality of light emitting elements such as lamps 11a and 11b are used, and the viewing angle can be widened even if light emitted from each light emitting element is incident on the liquid crystal display panel 1333 obliquely (light rays 1232a and 1232b). Can do. Therefore,Reference examples related to the present inventionIn the viewfinder, the number of light emitting elements (lamps 11) is not limited to one. This is because the use of a plurality of light emitting elements has the effect of widening the viewing angle and making it easier to see the displayed image.
[0344]
More thanReference examples related to the present inventionThe viewfinder was composed of a single liquid crystal display panel 1333. However, the viewfinder of the present invention is not limited to this, and includes, for example, the configuration shown in FIG.
[0345]
In FIG. 95, reference numeral 952 denotes a PBS (polarization beam splitter), which is marketed by many optical manufacturers (for example, 03PBS025 by Nippon Melles Griot). A dielectric thin film is laminated on the photosynthetic surface 951 of the PBS 952, and reflects or passes P-polarized light or S-polarized light.
[0346]
The light modulated by the liquid crystal display panel 1333 a is reflected by the light combining surface 951 of the PBS 952 (P-polarized light or S-polarized light) and enters the magnifying lens 1336. On the other hand, the light modulated by the liquid crystal display panel 1333b passes through the light combining surface 951 of the PBS 952 (S-polarized light or P-polarized light) and enters the magnifying lens 1336. Since the observer tries to superimpose the images on the two liquid crystal display panels 1336, the number of pixels is doubled. Therefore, high definition display can be realized. Instead of the PBS 952, a half mirror that transmits half of the light may be used.
[0347]
When a half mirror is used, the light emitted from the lamp 11a enters the liquid crystal display panel 1333a, and the light emitted from the liquid crystal display panel 1333a can be considered as a half mirror (PBS 952 in FIG. 95 is replaced with a half mirror). ). The half mirror reflects half of the light to the magnifying lens 1336 side. On the other hand, light emitted from the lamp 11b enters the liquid crystal display panel 1333b, and light emitted from the liquid crystal display panel 1333b enters the half mirror. Similarly, the half mirror reflects half of the light toward the magnifying lens 1336. The optical image of the liquid crystal display panel 1333a and the optical image of the liquid crystal display panel 1333b are shifted in position by a half pixel, and the two optical images are superimposed.
[0348]
Since the liquid crystal display panel is formed with a black matrix, the optical image of the pixel of the other liquid crystal display panel 1333b is superimposed on the optical image of the black matrix of one liquid crystal display panel 1333a. By superimposing as described above, the definition of the display image is improved. Needless to say, the sampling timing of the video signals of the two liquid crystal display panels is shifted by half a pixel.
[0349]
Similarly, a case where there are three or more liquid crystal display panels 1333 can be considered. The configuration is shown in FIG. Reference numeral 953 denotes a dichroic mirror. The lamp 11a emits red light, and light from the lamp enters the liquid crystal display panel 1333a. It is assumed that a red video signal is applied to the liquid crystal display panel 1333a. The red light modulated by the liquid crystal display panel 1333 a is reflected by the dichroic mirror 953 a and enters the magnifying lens 1336. It is assumed that the lamp 11b emits green light and a green video signal is applied to the liquid crystal display panel 1333b. The green light modulated by the liquid crystal display panel 1333 b passes through the dichroic mirror 953 and enters the magnifying lens 1336. In addition, it is assumed that the lamp 11c emits blue light, and a blue video signal is applied to the liquid crystal display panel 1333c. The blue light modulated by the liquid crystal display panel 1333c is reflected by the dichroic mirror 953a and enters the magnifying lens 1336. An observer (not shown) sees an image modulated by three liquid crystal display panels 1333 and synthesized by a dichroic mirror 953. Accordingly, the number of pixels is three times that of one liquid crystal display panel 1333, and high-definition image display can be realized.
[0350]
In FIG. 120, the configuration for improving the viewing angle using the two lamps 11 has been described. However, there is a method of adjusting the viewing angle in an appropriate direction with one lamp 11. This method will be described with reference to FIG. The viewing angle may be set in a direction that is most easily seen by the observer. In order to adjust the viewing angle, the center of the lens 552 may be changed from the center axis 961 of the lamp 11 and the liquid crystal display panel 1333. That is, if the central axis is deviated, the angle of the principal ray incident on the liquid crystal display panel 1333 is hardened. Therefore, the position of the Fresnel lens 552 may be shifted by x, or the position of the lamp 11 may be slightly shifted from the central axis 961. By shifting the position, the observer can optimally adjust the position so that the display image on the liquid crystal display panel 1333 can be seen. By applying this technical idea to the viewfinder in the present embodiment, the observer can easily adjust the optimal viewing direction.
[0351]
The above can be applied not only to the viewfinder but also to a display area 971 attached to, for example, a telephone. The explanatory diagrams are shown in FIGS. In the display area 971 of the telephone set, the telephone number of the other party is displayed, and the display is not desired by other people for security reasons. A display device including the lamp 11, the condensing lens 552, and the display panel 1333 in this embodiment has a narrow viewing angle (viewing angle) at which a display image can be seen. Therefore, it is visible only to the person making the phone call, and it has a security effect. However, since the viewing angle is narrow, the person using the telephone cannot see the display image in the display area 971 unless the chief ray is directed in the optimum direction. For example, in the case of FIG. 98, when the direction of the chief ray is a, the viewer A can see the display image but cannot be seen by the viewer B who is shorter than that. Therefore, by moving the position of the lamp 11 or the position of the condenser lens 552 in the direction of the arrow, only the observer B (telephone user) can be seen.
[0352]
Needless to say, the position adjustment of the condenser lens 552 can be automatically performed. When the user picks up the handset 974 or pushes the push button portion, the user is approaching the telephone body 973. At that time, infrared rays are generated from infrared LEDs 975a to 975d (see FIG. 97 (b)) attached to the telephone body 973, and reflected light reflected by the user is detected by the light receiving element 976. The outline such as the height of the user can be known by the above operation. If the height of the back is known, the condenser lens 552 may be moved by the amount of movement x set in advance with respect to the height of the back.
[0353]
The technical idea of using the Fresnel lens 552 and the diffusion sheet 15 described in FIG. 83 is not applied only to the viewfinder, but can also be applied to a projection display device as shown in FIG. A metal halide lamp 1221a corresponds to the light emitting means, and the concave mirror 1221b and the UVIR cut filter 1221c constitute the illumination optical system 1221. The Fresnel lens 552 makes the light from the illumination optical system 1221 substantially parallel and enters the liquid crystal display panel 1333. This is to prevent the grooves of the diffusion sheet 15 and the Fresnel lens 552 from being projected onto a screen (not shown). The projection lens 1222 enlarges and projects the modulated image of the liquid crystal display panel 1333 on the screen.
[0354]
FIG. 122A shows a liquid crystal display panel 1333 provided with a color filter 1223 for color display. Even without the color filter 1223, a color image can be displayed with the configuration of FIG. White light emitted from the illumination optical system 1221 is separated into three lights of blue, green, and red by a dichroic mirror 953. A microlens array 1224 in which microlenses 1225 are arranged in a matrix is attached to the liquid crystal display panel 1333. One microlens 1225 corresponds to three pixels 244 (three sets of blue, green, and red). The blue light enters the pixel 244b through the microlens 1224, the green light enters the pixel 244b, and the red light enters the pixel 244c. Therefore, color display can be performed without the color filter 1223.
[0355]
  Reference examples related to the present inventionThe technical idea can be applied to other devices. For example, the present invention can also be applied to a stereoscopic display device without glasses (3D display system) shown in FIG. An image splitter 1231 is correctly aligned with each pixel of the liquid crystal display panel 1333. Each of the light emitting elements (lamps 11a and 11b) is provided with a reflection mirror 833a or 833b, and emits light toward the Fresnel lens 552. Each light emitting element is disposed at a substantially focal position of the Fresnel lens 552.
[0356]
The principal ray 1232a of the lamp 11a is inclined by an angle + θ with respect to the normal line of the Fresnel lens 552 (or the liquid crystal display panel 1333). On the other hand, the principal ray 1232b of the lamp 11b is inclined by an angle −θ with respect to the normal line of the Fresnel lens 552 (or the liquid crystal display panel 1333). In the image splitter 1231, openings 1241 and light shielding parts 1242 are alternately formed (see FIG. 124). The light shielding portion 1242 is exemplified by a matrix shape or a stripe shape.
[0357]
124Reference examples related to the present inventionIt is explanatory drawing of a 3D display system. Light from the lamp 11 enters the liquid crystal display panel 1333. The principal ray 1232a mainly passes through the pixels of the right eye image 1244, and the principal ray 1232b passes through the pixels of the left eye image 1243. The light blocking section 1242 of the image splitter 1231 prevents the light that has passed through the pixels of the right eye image 1244 from reaching the left eye of the observer 1245 and the light that has passed through the pixels of the left eye image 1243 reaches the right eye. It has a function to prevent it. Further, the opening 1241 of the image splitter 1231 allows the light that has passed through the pixels of the left eye image 1243 to reach the left eye of the observer 1245, and the light that has passed through the pixels of the right eye image 1244 reaches the right eye. It has a function to make it reach. Naturally, the left eye image is displayed on the pixel of the left eye image 1243, and the right eye image is displayed on the pixel of the right eye image on the liquid crystal display panel 1333. This can be realized by switching the video signal for the right eye and the video signal for the left eye with an analog switch or the like for each pixel to obtain one video signal input to the liquid crystal display panel 1333.
[0358]
In FIG. 124, a small fluorescent discharge tube is used as a light emitting element. However, as shown in FIG. 52, a flat fluorescent lamp 521 (for example, Ushio Electric Co., Ltd. product number UFU07E852) can also be used as a light emitting element (see FIG. 125). Further, the LED of FIG. 51 can also be used. As shown in FIG. 125, the flat fluorescent lamp 521 has a booster coil 1251 connected to the back surface. There may be one light emitting element. Further, instead of the Fresnel lens 552, a convex lens 1252 made of plastic or the like may be used. This is because the light collecting function is the same. The convex lens has a flat surface or a surface with a large radius of curvature facing the flat fluorescent lamp 521 side. This is to make it easier to satisfy the sine condition and to improve the luminance uniformity of the display image on the liquid crystal display panel 1333.
[0359]
However, the convex lens is not limited to the plano-convex lens and may be a biconvex lens. A lenticular screen (lens) may be used as the image splitter 1231 in FIG. This is because a lenticular screen is formed with a kamaboko-shaped lens, and there is no change in that the transmitted light for the left eye and the transmitted light for the right eye can be selectively controlled by the lens. For example, as a configuration in which a lenticular lens (lenticular screen) is added to the liquid crystal display panel 1333, the configuration in FIG. 127 is exemplified.
[0360]
In FIG. 123, left eye light and right eye light are separated using an image splitter 1231. The same function can also be realized by using a prism plate 1341 as shown in FIG. The prism plate 1341 is a triangular plate.
[0361]
Light with narrow directivity emitted from the condensing means 1252 enters the prism plate 1341, and the traveling direction of the light can be changed according to Snell's law. Two adjacent pixel electrodes 244 correspond to the triangle of one prism plate 1341. A “dotted line” ray that passes through the prism plate 1341 passes through a pixel 244b that displays an image for the right eye. On the other hand, the “solid line” light beam passes through a pixel 244a that displays an image for the left eye. Accordingly, light for the right eye and left eye is formed by the prism plate 1341, and the active matrix liquid crystal display panel 1333 alternately displays for the right eye and for the left eye for each pixel, thereby allowing the observer to make a three-dimensional image. (3D) Display can be seen.
[0362]
In addition, when the triangle of the prism plate 1341 is conspicuous, the scattering means (the diffusion plate 15) may be disposed between the prism plate 1341 and the liquid crystal display panel 1333 or on the light emission side of the liquid crystal display panel 1333. Therefore, the technical idea of using the diffusion plate 15 in the viewfinder is also utilized in 3D.
[0363]
In FIG. 134 and the like, a prism plate 1341 is used to form light for the right eye and light for the left eye. Other methods can also be realized by the method shown in FIG.
[0364]
In FIG. 135, the light from the lamp 1221a is converted into substantially parallel light (light having a narrow directivity) and emitted by the parabolic mirror 1221b. The emitted light is cut into infrared rays and ultraviolet rays by the UVIR cut filter 1221c, and only visible light is emitted. Half of the light is reflected by the half mirror 1351 as shown by a dotted line, and the light that has passed is reflected by the mirror 1352 as shown by a solid line. The half mirror 1351 and the mirror 1352 may be a dichroic mirror or a dichroic prism.
[0365]
A microlens array 1225 is attached to the liquid crystal display panel 1333 with an optical binder, and one microlens 1225 corresponds to two pixels 244a and 244b. The dotted light passes through the pixel 244a and the solid light passes through the pixel 244b by the microlens 1225. This becomes the light for the left eye and the light for the right eye. With the above configuration, 3D display can be performed as in FIG.
[0366]
The above 3D display system alternately displays a left-eye image and a right-eye image for each pixel on one liquid crystal display panel 1333. However, in the above configuration, if one eye is considered, only half the number of pixels of the liquid crystal display panel can be seen. That is, it is the same as viewing a display screen having a half of the number of pixels of the liquid crystal display panel.
[0367]
FIG. 129 shows the configuration of a 3D display system that solves this problem. It is not employed in the image splitter 1231 or the like. The principal rays of the two lamps 11 are inclined at an angle θ with respect to the normal line of the liquid crystal display panel 1333, and the light collecting means (lens 1252) converts the light emitted from the lamps 11 into light having a narrow directivity. Is the same as FIG. That is, mainly the light from the lamp 11a becomes light for the left eye, and the light from the light emitting element 11b becomes light for the right eye. This is because the directivity of light emitted from the liquid crystal display panel 1333 is sufficiently narrow. As the liquid crystal display panel 1333, an active matrix type TN liquid crystal display panel is employed.
[0368]
FIG. 131 is a block diagram of a circuit for producing a video signal applied to the liquid crystal display panel 1333. The playback device a and the playback device b can output video signals in synchronization with the horizontal scanning period (H period). Synchronization is performed by the synchronization circuit 1311. These synchronization methods and devices can be easily configured by those who are involved in the video field, and will not be described. The video signals read from the reproducing devices a and b are converted from analog to digital by an A / D converter 1313 and held as data in memories 1314a and 1314b made of SRAM. Data are selectively read from the memories a and b by switching the switch of the switching circuit 1315. The read video data is digital-analog converted by a D / A converter 1316, and a horizontal synchronizing signal or the like is added to form a video signal, which is added to the terminal a of the switch SW1 in FIG.
[0369]
Reading from the memory a is performed in a half period (double speed reading) of one field (1F). During the remaining half period, 0 data (no video data = black display (no display)) is transferred to the D / A converter 1316. Similarly, reading from the memory b is performed in 1/2 period of 1 field (1F), and 0 data (no video data = black display (no display)) is input to the D / A converter 1316 in the remaining 1/2 period. Transferred. That is, the left-eye video signal remains in the first field 1/2 period, the remaining 1/2 period is not displayed, and the right-eye video signal remains in the next second field 1/2 period. The D / A converter 1316 outputs a video signal that is not displayed during the half period. Note that the ½ period described above is for convenience of explanation and ease of circuit configuration, and is not limited to this. For example, the video signal may be not displayed during the 3/4 period and the remaining 1/4 period may not be displayed. Further, it is not limited to one field, and may be one frame. For example, the video signal for the left eye may be displayed in the ½ period (= 2 fields) of one frame, and the remaining ½ period may not be displayed. However, if the interval at which the video signal for the left eye is displayed becomes longer, there will be a problem that flickering occurs, or the displayed image is not continuous and the moving image becomes awkward. In the case of a still image, the display interval of the video signal may be long, but in the case of a moving image display, it will be a problem. From this point of view, it is preferable that the appearance interval of the video signal for the left eye is one frame (= 2 fields).
[0370]
FIG. 130 illustrates an image display state of the liquid crystal display panel 1333, lighting timings of the two light emitting elements 11a and 11b, and signal polarities applied to the pixel electrodes of the liquid crystal display panel 1333.
[0371]
First, the display state of the liquid crystal display panel 1333 will be described (second column from the left in the figure). (1) indicates a non-display state (in the non-display state, the effective display area of the liquid crystal display panel is indicated by diagonal lines). Further, for ease of explanation, the video display uses the letter “F” as an example, and the display for the left eye is indicated by a solid line and the display for the right eye is indicated by a dotted line. In (2), images are displayed sequentially from the top of the display screen, and (3) shows a state in which the entire screen is displayed. Next, in (4), the non-display state starts from the top of the screen. (5) shows a state in which no display is made (black display). Note that (2) to (5) are not performed quantitatively but are performed continuously. That is, in the liquid crystal display panel 1333, a gate drive circuit (not shown) applies a TFT turn-on voltage to the gate signal line every horizontal scanning period (1H), and sequentially scans the turn signal to the gate signal line. Do.
[0372]
In (2) to (5), an arbitrary pixel is displayed as an image for 1/2 hour of the period of one field (1F). At this time, the left-eye light emitting element 11a is turned on (on), and the right-eye light emitting element 11b is turned off (off). Accordingly, the left-eye image is displayed on the liquid crystal display panel 1333, and the optical image of the image display reaches the left eye of the observer by the light emitted from the light emitting element 11a. The reason for black display (no display) is that the active matrix type liquid crystal display panel (rather than the liquid crystal display panel) has a memory property. The memory property means a property that a signal written to the pixel electrode 244 is held until the signal is next applied to the pixel electrode 244. If black display is not performed, the display for the left eye and the display for the right eye are simultaneously displayed on the liquid crystal display panel 1333. Even if the left-eye lamp 11a and the right-eye lamp 11b are alternately turned on and off, the left-eye image reaches the right eye and the right-eye image reaches the left eye even if the left-eye lamp 11a and the right-eye lamp 11b are alternately turned on and off. Don't be. As shown in FIG. 130, after displaying the left-eye image, once the voltage held in all the pixel electrodes 244 is reset (erased) and a new right-eye image is displayed, the left-eye image is displayed. And the right eye image can be selectively made to reach the left eye and the right eye, respectively.
[0373]
(6) to (9) indicate that an image for the right eye is being displayed. At this time, the left-eye lamp 11a is turned off (off), and the right-eye lamp 11b is turned on (on). The right-eye video is displayed on the liquid crystal display panel 1333 from the upper end of the screen. After the right-eye video is completely displayed as shown in (7), black display is made from the top as shown in (8). To go. The states (2) to (5) (left-eye video display state) and (6) to (8) (right-eye video display state) are repeated for each frame.
[0374]
Although the left-eye lamp 11a is turned on in the display state (2), the present invention is not limited to this, and it may be turned on as in the display state (1). Similarly, the right-eye lamp 11b may be turned on in the display state (5).
[0375]
The left end column of FIG. 130 shows the polarity of the signal applied to the pixel electrode 244. The positive polarity is indicated by “+” and the negative polarity is indicated by “−” with respect to the potential of the counter electrode 243. Signals of the same polarity are applied to the row (lateral direction) of one pixel electrode 244. Also, the polarity is reversed for each row. That is, in FIG. 130A, a signal having the same polarity as that of the pixel electrodes 74a and 74b and a polarity opposite to that of the pixel electrodes 244a and 244c is applied.
[0376]
In the next field (FIG. 130 (b)), the signal polarity of each pixel electrode is made opposite to that in the previous field (FIG. 130 (a)). That is, the pixel electrode 244c in FIG. 130A is applied with the “−” polarity, whereas the pixel electrode 244c in FIG. 130B is applied with the “+” polarity. Thus, by inverting the signal polarity applied to the pixel electrode 244 for each field, the occurrence of flicker can be prevented and a good image display can be realized.
[0377]
In FIG. 130, the light emitted from the lamp 11 a is incident on the left eye and the light emitted from the lamp 11 b is incident on the right eye using a condensing unit (lens 1252). Similar 3D display can be realized by using a lenticular lens 1271 as shown in FIG. 127 instead of the light condensing means. The image display state of the liquid crystal display panel 1333 and the light emission state of the light emitting elements (lamps 11a and 11b) are the same as those shown in FIG. However, it is necessary to consider the lamps 11a and 11b, but there is no basic problem.
[0378]
128 is an explanatory diagram of an optical path and the like passing through the lenticular lens 1271 part. The lenticular lens 1271a is optically coupled (OC) with the array substrate 242 through an optical coupling agent 901a, and the lenticular lens 1271b is OCed with the counter substrate 241 through an optical coupling agent 901b. This is for preventing interface reflection and the like.
[0379]
Light (solid line) emitted from the lamp 11a enters the lenticular lens 1271a, passes through the pixel electrode 244 of the liquid crystal display panel 1333, is refracted by the lenticular lens 1271b, and enters the right eye. On the other hand, the light (dotted line) emitted from the lamp 11b enters the lenticular lens 1271a, similarly passes through the pixel electrode 244 of the liquid crystal display panel 1333, is refracted by the lenticular lens 1271b, and enters the left eye.
[0380]
From the above, it can be understood that the light emitted from the lamps 11a and 11b can selectively reach the right eye and the left eye. That is, the lenticular lens 1271 has the same function as the light condensing means (lens 1252) in FIG. Therefore, if the display method of FIG. 130 is implemented, 3D display can be performed.
[0381]
The technical idea of having two lamps can also be realized with the configuration of FIG. In the light shielding plate 1393 and the light shielding pattern 1392, two micro holes (1391a and 1391b) are formed for one microlens 1225. The light radiated from the hole 1391a is made into light for the right eye by the micro lens 1225, and the light radiated from the hole 1391b is made into light for the left eye by the micro lens 1225 in the same manner. As described above, the light for the left eye and the light for the right eye with good directivity can be produced with one microlens array 1224. Further, it is possible to realize not only the micro lens array but also the cell hook (cylindrical) lens array of FIG.
[0382]
  Reference examples related to the present inventionSince the 3D display uses the lamp 11 that can be regarded as a point light source, the directivity of light emitted from the liquid crystal display panel 1333 is narrow. Therefore, the light for the left eye and the light for the right eye can be well separated. In addition, by setting the angles of chief rays emitted from the two lamps 11 to + θ and −θ, an observer can see a display image well at the center of the screen of the liquid crystal display panel 1333. Moreover, it is easy to change the angle of the chief ray. It is also easy to change the position of the lamp 11. For example, if the light emitting element (lamp 11) is moved to the dotted line position in FIG. 33, the display image on the display panel 223 can be displayed in 3D when viewed from an oblique direction.
[0383]
In the 3D display system including two lamps, it is easy to adjust the observer so that the 3D image can be viewed optimally. The angle θ emitted from the lamp 11 may be adjusted as shown in FIG. For example, as shown in FIG. 132A, when the observer's eye 1401 is relatively away from the display screen of the display panel 1333 (when the display screen is viewed from a relatively long distance), the angle θ₁Make it smaller. On the other hand, as shown in FIG. 132B, when the observer's eye 1401 is relatively close to the display screen, the angle θ2 may be increased.
[0384]
More specifically, the configuration is as shown in FIG. The lamps 11 having the reflection mirror 833 are attached to the arms 1412a and 1412b, and screws 1411a and 1411b are attached. One end of the arm 1412 is attached to the adjustment plate 1414 with screws 1411c. Also, an arm 1412 is attached to the hole of the slide plate 1413 with screws 1411a and 1411b.
[0385]
By pulling the adjustment plate 1414 in the right direction, the space between the two lamps 11 is opened. Further, the distance between the lamps 11 is reduced by pushing. As described above, by adjusting the adjustment plate 1414 by the observer, the 3D display can be easily seen optimally.
The above viewfinder converts light radiated from a small light emitter of a light emitting element into a wide solid angle into light having a narrow directivity by a Fresnel lens or a parabolic mirror. Since the image is displayed by being modulated by the liquid crystal display panel 1333, power consumption is small and luminance unevenness is small. In addition, since the driving circuit of the lamp 11 has a simple configuration as compared with a conventional viewfinder using a backlight, a compact and lightweight viewfinder can be provided. If a PD liquid crystal display panel is used as the liquid crystal display panel, the power consumption can be further reduced as compared with the TN liquid crystal display panel.
Further, by disposing the diffusion plate 15 between the Fresnel lens 522 and the liquid crystal display panel 1333, the pixel 244 of the liquid crystal display panel 1333 interferes with the groove of the Fresnel lens 522, and moire is generated. Since it is possible to prevent the grooves from being visually recognized, a good image display can be realized. In addition, an arbitrary viewing angle and brightness (brightness, brightness, etc.) of the display image can be adjusted by using the diffusion plate 15 as a PD liquid crystal display panel. Moreover, since what can be considered as a point light source can be used as the lamp | ramp 11, a favorable 3D display is also realizable.
【The invention's effect】
  As is apparent from the above description, the present invention can provide, for example, a liquid crystal display device with improved display quality, and a viewfinder and a camera using the same.
[Brief description of the drawings]
[Figure 1]Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
[Figure 2]Reference examples related to the present inventionIt is sectional drawing of the light source part of a viewfinder.
[Fig. 3]Reference examples related to the present inventionIt is sectional drawing of the light source part of a viewfinder.
[Fig. 4]Reference examples related to the present inventionIt is sectional drawing of the light source part of a viewfinder.
[Figure 5]Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
[Fig. 6]Reference examples related to the present inventionIt is sectional drawing of the light source part of a viewfinder.
[Fig. 7]Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
[Fig. 8]Reference examples related to the present inventionIt is sectional drawing of the light source part of a viewfinder.
FIG. 9Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG. 10Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG. 11Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG.Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG. 13Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG. 14Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG. 15Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 16Reference examples related to the present inventionIt is explanatory drawing of the drive method of a lamp.
FIG. 17Reference examples related to the present inventionIt is explanatory drawing of the drive method of a lamp.
FIG. 18Reference examples related to the present inventionIt is explanatory drawing of the drive method of a lamp.
FIG. 19Reference examples related to the present inventionIt is explanatory drawing of the drive method of a lamp.
FIG. 20Reference examples related to the present inventionIt is explanatory drawing of the drive method of a lamp.
FIG. 21Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 22Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 23 is a cross-sectional view of a polymer-dispersed liquid crystal display panel.
FIG. 24 is an explanatory diagram of a polymer-dispersed liquid crystal display panel.
FIG. 25Reference examples related to the present inventionIt is sectional drawing of the light source part of a viewfinder.
FIG. 26Reference examples related to the present inventionIt is sectional drawing of the light source part of a viewfinder.
FIG. 27Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 28Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG. 29Reference examples related to the present inventionIt is sectional drawing of the lamp | ramp of a viewfinder.
FIG. 30Reference examples related to the present inventionIt is sectional drawing of the lamp | ramp of a viewfinder.
FIG. 31Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG. 32Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
FIG. 33Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
FIG. 34Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
FIG. 35Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
FIG. 36Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
FIG. 37Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG. 38Reference examples related to the present inventionIt is a perspective view of the light source part of a viewfinder.
FIG. 39Reference examples related to the present inventionIt is a perspective view of the light source part of a viewfinder.
FIG. 40Reference examples related to the present inventionIt is a perspective view of the light source part of a viewfinder.
FIG. 41Reference examples related to the present inventionIt is a perspective view of the light source part of a viewfinder.
FIG. 42Reference examples related to the present inventionIt is explanatory drawing of the drive method of a lamp.
FIG. 43Reference examples related to the present inventionIt is explanatory drawing of a video camera.
FIG. 44Reference examples related to the present inventionIt is explanatory drawing of a video camera.
FIG. 45Reference examples related to the present inventionIt is explanatory drawing of the drive method of a lamp.
FIG. 46Reference examples related to the present inventionIt is explanatory drawing of the drive method of a lamp.
FIG. 47Reference examples related to the present inventionIt is explanatory drawing of the lamp | ramp of a viewfinder.
FIG. 48Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
FIG. 49Reference examples related to the present inventionIt is explanatory drawing of the drive method of the lamp of a viewfinder.
FIG. 50 is an explanatory diagram of an LED.
FIG. 51 is an explanatory diagram of an LED.
FIG. 52 is an explanatory diagram of a phosphor screen light emitting device.
FIG. 53Reference examples related to the present inventionIt is explanatory drawing of a video camera.
FIG. 54Reference examples related to the present inventionIt is explanatory drawing of an electronic still camera.
FIG. 55Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 56Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 57Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 58Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 59Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 60Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 61Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 62Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
FIG. 63Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
FIG. 64Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 65Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 66Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 67Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 68 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 69 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 70 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 71 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 72 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 73 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 74 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 75 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 76 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 77 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 78 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 79 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 80 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 81Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 82Reference examples related to the present inventionIt is a perspective view of a viewfinder.
FIG. 83 is a cross-sectional view of the viewfinder of the present embodiment.
FIG. 84 is a cross-sectional view of the viewfinder of the present embodiment.
FIG. 85 is an explanatory diagram of a video camera according to an embodiment of the present invention.
FIG. 86 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 87Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 88Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 89Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
FIG. 90Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
FIG. 91Reference examples related to the present inventionIt is explanatory drawing of the light source part of a viewfinder.
FIG. 92Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 93Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 94Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 95Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 96 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 97Reference examples related to the present inventionIt is explanatory drawing of a display panel.
FIG. 98Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 99Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
Fig. 100Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 101Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 102Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 103Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
Fig. 104Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
Fig. 105Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
Fig. 106Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 107Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 108Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 109Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 110Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 111Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 112Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 113Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 114 is an explanatory diagram of the viewfinder of the present embodiment.
FIG. 115Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 116 is a cross-sectional view of the viewfinder of the present embodiment.
Fig. 117Reference examples related to the present inventionIt is a perspective view of a viewfinder.
FIG. 118Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 119Reference examples related to the present inventionIt is sectional drawing of a viewfinder.
FIG. 120Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 121Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 122Reference examples related to the present inventionIt is a block diagram of a display apparatus.
FIG. 123Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
FIG. 124Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
FIG. 125Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
Fig. 126Reference examples related to the present inventionIt is explanatory drawing of the lens used for a display apparatus.
Fig. 127Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
FIG. 128Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
Fig. 129Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
Fig. 130Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
FIG. 131Reference examples related to the present inventionIt is explanatory drawing of the drive method of a display apparatus.
FIG. 132Reference examples related to the present inventionIt is explanatory drawing of the drive method of a display apparatus.
FIG. 133Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
FIG. 134Reference examples related to the present inventionIt is explanatory drawing of a display apparatus.
Fig. 135Reference examples related to the present inventionIt is a block diagram of a display apparatus.
136 is an external view of a viewfinder. FIG.
FIG. 137 is a cross-sectional view of a conventional viewfinder.
FIG. 138 is an explanatory diagram of a light source unit of a conventional viewfinder.
Fig. 139Reference examples related to the present inventionIt is explanatory drawing of a viewfinder.
FIG. 140Reference examples related to the present inventionIt is a design example of a viewfinder.
FIG. 141Reference examples related to the present inventionIt is a design example of a viewfinder.
Fig. 142Reference examples related to the present inventionIt is a design example of a viewfinder.
FIG. 143Reference examples related to the present inventionIt is a design example of a viewfinder.
Fig. 144Reference examples related to the present inventionIt is a design example of the parabolic mirror of the viewfinder.
[Explanation of symbols]
11 Lamp
12 Parabolic mirror
14 Base substrate
15 Diffusion (scattering) sheet
16 Lamp potential terminal
16a, b Filament terminal
16c Anode terminal
17 Lamp circuit components
20 Sealing member
21,21a Lamp case
22 Reflecting surface
23 phosphor
24 Filament
25 Anode electrode
26 Buffer member
27 Socket
28 terminals
29 Solder
30, 30a protrusion
31 Reflective film
32 light reflector
15a Diffuser
43 Embossed surface
51 rays
52 Effective display area
71 Low brightness area
72 Rubber Cap
73 Protrusion
91 Reflective film
101 Condensing cap
102 Condensing prism
103 Adhesive
104 Transparent resin
105 Reflector tube
106 Diffuser
107 reflective cap
111 Transparent conductive film (ITO)
112 Antistatic film
121 conductor
131 wire mesh
161 Timer circuit
162 Variable power supply
163 Variable resistance (variable current element)
171 Inverter
172a, b Analog switch
173a, b Current limiting resistor
181 Photosensor
182 operational amplifier
183 Photodetection circuit
184 Oscillator circuit
185 amplifier
191 amplifier
192 Phase division circuit
193 Output switching circuit
194 Drive circuit controller
195 Source drive circuit
196 Gate drive circuit
197, 198 Power supply
201a, b DCDC converter
202 battery
204 Current detection circuit
211 Outside
212 Aperture knob
213 iris diaphragm
249 Source signal line
230 Color filter
231 Transparent resin
241 Counter electrode substrate
242 Array substrate
243 Counter electrode
244 Pixel electrode
245 Water droplet liquid crystal
246 polymer
247 Incident light
248 Light modulation layer (liquid crystal layer)
291 Protective film (SiO₂)
301 Mounting glass
311 Light emitting area
312 Marker
313 Indentation
314 Transparent protrusion
331 Diffusion (scattering) part
332 Diffusion (scattering) point
381 Transparent holder (resin resin)
382 Holder fixing part
391 Parabolic mirror
401 Convex
411 Diffusion (scattering) plate
421 Thermistor
422 Comparator
423 CPU
424 switch circuit
425 operational amplifier
426 FET
431 Video camera body
432 Imaging lens unit
433 Switch (SW)
434 connection
435 Recording switch
471 Sealing resin
501 terminal
502 illuminant
503 Resin lens
504 Lens surface
505 Apex of lens surface
506 Lens surface normal
507 Center of curvature of lens surface
508 Image of illuminant by lens surface
521 Surface fluorescent lamp
531 CCD sensor
532 Light Emitting Element Power Supply Circuit
533 Liquid crystal display panel drive circuit
534 Playback circuit
541 Still camera body
551 reflector
552 Illumination lens (convex lens)
553 Auxiliary lens
601 Lens surface
602 Fresnel surface
603 Convex lens
604 Fresnel lens
611 Flat part
621 Light guide plate
622 Diffusion part
631 Prism plate
641 Eyepoint
681 Panel holder
691 Display
711 socket
712 knob
713 Contraction part 1
714 Contraction part 2
715 optical axis
751 Mirror
811 Insertion part
821 Knob
831 reflector
1336b concave lens
851 Fastener
861 Panel mounting part
862 Bellows
863 axis of rotation
864 Lens mount
871 case
872 rays
881 Cylindrical lens
882 Small fluorescent tube
883 reflector
901 Transparent adhesive
911 ellipsoidal mirror
912 Shading plate
921 Diffusion part
931 circular aperture
932 diffraction grating
951 Photosynthetic surface
952 PBS
953 Dichroic Mirror
961 Optical axis
971 Display area
972 Push button
973 Phone body
974 Handset
975 infrared LED
976 light receiving element
991 Mounting holder
1011 Transparent substrate
1012 Light absorption film
1022, 1023, 1024, 1031 interface
1031 interface
1041 PD LCD panel
1042 Signal source
1043 Signal amplitude variable device
1044 Sealing resin
1045 glass substrate
1046 ITO electrode
1047 PD liquid crystal layer
1051 Optical coupling layer
1091 aperture
1111 Light guide
1121 Reflective film
1131 optical fiber
1141 sunlight
1142 Photosensor
1143 Fresnel lens
1151 Hysteresis comparator circuit
1152 Photodetection circuit
1153 Switch circuit
1171 Shading cover
1211 Reflective Fresnel lens
1221 Light source
1221a Metal halide lamp
1221b Concave mirror
1221c UVIR cut mirror
1222 Projection lens
1223 Color filter
1224 micro lens array
1225 micro lens
1231 Image Splitter
1232 chief rays
1241 opening
1242 Shading part
1243 Left eye image
1244 Right eye image
1245 observer
1251 Booster coil
1252 Condensing lens (convex lens)
1261 Cell Hook Lens
1271 lenticular lens
1311 Synchronous circuit
1312 Playback device
1313 A / D conversion circuit
1314 frame memory
1315 switching circuit
1216 D / A converter circuit
1401a Right eye
1401b left eye
1411 screw
1412 arm
1413 slide plate
1414 Adjustment plate
1341 Prism plate
1351 Half Mirror
1352 mirror
1321 Body
1323 Mounting bracket
1331 fluorescent tube box
1332 eyepiece cover
1333 LCD panel
1334 Polarizing plate
1335 Mounting holder
1336 Magnifying lens
1341 Luminescent pattern of fluorescent tube

Claims (1)

A liquid crystal display panel;
A lighting means having a left-eye light-emitting element and a right-eye light-emitting element that generates white light for illuminating the liquid crystal display panel;
Signal processing means for performing signal processing for displaying a left-eye image and a right-eye image on the liquid crystal display panel;
Illumination control means for controlling on / off of the left-eye light-emitting element and the right-eye light-emitting element,
The signal processing means displays the left-eye image on the liquid crystal display panel, displays the left-eye image, and then displays a black image on the liquid-crystal display panel. After displaying the image for the right eye and displaying the image for the right eye, the signal processing for displaying the black image is alternately repeated,
The illumination control unit is configured to perform illumination control for turning on and off the light emitting element for the left eye in synchronization with the display of the left eye image and light emission for the right eye in synchronization with the display of the right eye image. A liquid crystal display device characterized by alternately repeating illumination control for turning elements on and off .

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