JP4127028B2 - Laser light irradiation device and image display device - Google Patents

Description

そして、Ｂレーザ可変部２４を通過して波面曲率の変化したレーザ光が観察者の網膜上に投影されることにより、観察者は、画像信号供給回路４０で生成された奥行信号Ｌの示す奥行きの画像を認識することとなる。即ち、画像信号供給回路４０から奥行信号Ｌを入力した波長指示部４２は、Ｂレーザ可変部２４を通過後のレーザ光の波面曲率を奥行信号Ｌの示す奥行きに対応する値とするためにＢレーザ出力部１６が出力すべきレーザ光の波長値を、Ｂ波長指示値λｂとしてレーザ光出力部１８へ出力するのである。
【００３５】
次に、本網膜走査型ディスプレイ１０が、外部機器からの画像信号を入力してから観察者の網膜上に画像を投影するまでの過程について説明する。
まず、外部機器からの画像信号が画像信号供給回路４０に入力されると、画像信号供給回路４０にて、奥行信号Ｌ、強度信号Ｉｒ，Ｉｇ，Ｉｂ、垂直同期信号Ｙ及び水平同期信号Ｘが生成される。
【００３６】
そして、画像信号供給回路４０から波長指示部４２へ奥行信号Ｌが出力されると、その波長指示部４２にて、この奥行信号Ｌに対応するＲ波長指示値λｒ、Ｇ波長指示値λｇ及びＢ波長指示値λｂが求められ、この各波長指示値λｒ，λｇ，λｂがレーザ光出力部１８へ出力される。
【００３７】
また、画像信号供給回路４０から強度指示部４４へ強度信号Ｉｒ，Ｉｇ，Ｉｂが出力されると、その強度指示部４４にて、この強度信号Ｉｒ，Ｉｇ，Ｉｂに対応するＲ強度指示値Ｗｒ、Ｇ強度指示値Ｗｇ及びＢ強度指示値Ｗｂが求められ、この強度指示値Ｗｒ，Ｗｇ，Ｗｂがレーザ光出力部１８へ出力される。
【００３８】
そして、レーザ光出力部１８の各レーザ出力部１２，１４，１６が、波長指示部４２からの各波長指示値λｒ，λｇ，λｂ及び強度指示部４４からの各強度指示値Ｗｒ，Ｗｇ，Ｗｂに応じた波長及び出力強度のレーザ光を出力し、この各レーザ光が、対応する各レーザ可変部２０，２２，２４を通過して波面曲率が変化された後、全反射ミラー２６及び部分透過ミラー２８，３０によって合成される。
【００３９】
一方、画像信号供給回路４０から垂直走査駆動部４６へ垂直同期信号Ｙが出力され、この垂直同期信号Ｙに同期してガルバノミラー３６が往復駆動される。
また同様に、画像信号供給回路４０から水平走査駆動部４８へ水平同期信号Ｘが出力され、この水平同期信号Ｘに同期してポリゴンミラー３２が回転駆動される。
【００４０】
そして、全反射ミラー２６及び部分透過ミラー２８，３０によって合成されたレーザ光は、ポリゴンミラー３２の偏向面３２ａに入射され、ポリゴンミラー３２の回転運動により水平方向に走査されて第１リレー光学系３４によりガルバノミラー３６の偏向面３６ａに入射される。そして更に、ガルバノミラー３６の往復運動により垂直方向にも走査されて第２リレー光学系３８により観察者の瞳孔２へ入射される。こうして、網膜上に投影された画像が、観察者に認識されることとなる。
【００４１】
なお、本第１実施形態の網膜走査型ディスプレイ１０では、レーザ光出力部１８の各レーザ出力部１２，１４，１６が、レーザ光出力手段に相当し、各レーザ可変部２０，２２，２４が、曲率可変手段に相当し、波長指示部４２が各レーザ出力部１２，１４，１６について行う処理のそれぞれが、波長指示手段に相当している。また、ＬＤチップ５０が、温度依存型出射手段に相当し、温度調節素子５４及び制御部５８が、温度制御手段に相当している。また更に、ポリゴンミラー３２、第１リレー光学系３４及びガルバノミラー３６が、走査手段に相当し、第２リレー光学系３８が、光学手段に相当している。
【００４２】
以上のように、本第１実施形態の網膜走査型ディスプレイ１０によれば、各レーザ出力部１２，１４，１６により出力されるレーザ光の波長を変化させることで各レーザ可変部２０，２２，２４を通過後のレーザ光の波面曲率を変化させる構成により、レーザ光の波面曲率を高速に変化させることができる。その結果、高精度の立体画像を観察者に認識させることができる。
【００４３】
また、各レーザ出力部１２，１４，１６が、出力するレーザ光の波長を連続的に変化させることのできる構成であると共に、各レーザ可変部２０，２２，２４も、レーザ光の波長に応じて波面曲率を連続的に変化させることのできる構成であるため、レーザ光の波面曲率の微調整を容易に行うことができる。
【００４４】
また更に、各レーザ可変部２０，２２，２４は、ボールレンズ６０，６２を並設しただけの単純な構成であるため、低コストで実現できる。特に、波長分散特性の大きい材料で生成したボールレンズを用いることでレーザ光の波長の変化に対する波面曲率の変化が大きくなるようにしているため、十分な奥行きのある画像を観察者に認識させるために必要な波面曲率の変化幅を得るためのレーザ光の波長の変化幅を小さくすることができ、その結果、レーザ光の色の変化を人間が気にならない程度に抑えることができる。
【００４５】
加えて、各レーザ出力部１２，１４，１６のそれぞれに対応させて各レーザ可変部２０，２２，２４を設けているため、各レーザ出力部１２，１４，１６により出力されるレーザ光の波面曲率を別途補正する必要が無い。即ち、仮に、各レーザ出力部１２，１４，１６により出力されたレーザ光の波面曲率を共通のレーザ可変部を用いて変化させる構成とした場合、各色のレーザ光が共通のレンズを通過する際に各レーザ光の波面曲率の変化度合いに生じるズレ（色収差）を補正するため、各レーザ出力部１２，１４，１６により出力される各レーザ光の波面曲率を独立して補正する構成を別途設ける必要が生じる。これに対し、本実施形態の網膜走査型ディスプレイでは、このような構成を別途設ける必要が無い。
【００４６】
次に、第２実施形態の画像表示装置としての網膜走査型ディスプレイ７０について、図４を用いて説明する。
図４に示すように、第２実施形態の網膜走査型ディスプレイ７０は、第１実施形態の網膜走査型ディスプレイ１０（図１）の構成に加え、強度変換部７２を備えている。なお、図４において、図１に示した網膜走査型ディスプレイ１０と同じ構成要素については、同一の符号を付しているため、詳細な説明は省略する。
【００４７】
強度変換部７２は、画像信号供給回路４０から強度信号Ｉｒ，Ｉｇ，Ｉｂを入力すると共に、波長指示部４２から各波長指示値λｒ，λｇ，λｂを入力する。そして、強度変換部７２は、これらの値に基づいて新たな強度信号としての強度変換値Ｊｒ，Ｊｇ，Ｊｂを求め、この強度変換値Ｊｒ，Ｊｇ，Ｊｂを強度指示部４４へ出力する。
【００４８】
ここで、本網膜走査型ディスプレイ７０において、画像信号供給回路４０が生成した強度信号Ｉｒ，Ｉｇ，Ｉｂを、強度変換部７２により強度変換値Ｊｒ，Ｊｇ，Ｊｂに変換する理由について説明する。
観察者の網膜上に照射されるレーザ光の色は、Ｒレーザ出力部１２、Ｇレーザ出力部１４及びＢレーザ出力部１６のそれぞれによって出力されるレーザ光の色が一定の基準色であれば、各レーザ光の出力強度のバランスにより定まる。
【００４９】
しかしながら、本網膜走査型ディスプレイ７０では、レーザ光の波長を変化させることによりそのレーザ光の波面曲率を変化させるようにしているため、各レーザ出力部１２，１４，１６から出力されるレーザ光の色が正確には一定とならず、その結果、各レーザ光の出力強度のバランスを一定にしても、合成されたレーザ光の色が変化してしまう。
【００５０】
そこで、各レーザ出力部１２，１４，１６から出力されるレーザ光の色が変化しても、最終的に合成されたレーザ光が所望の色となるように、強度変換部７２により出力強度のバランスを補正するようにしているのである。具体的には、強度変換部７２は、下記式（１）〜式（３）に示すように、画像信号供給回路４０から入力した強度信号Ｉｒ，Ｉｇ，Ｉｂと波長指示部４２から入力した各波長指示値λｒ，λｇ，λｂとに基づき、赤（Ｒ），緑（Ｇ），青（Ｂ）の各色についての補正後の強度信号として、Ｒ強度変換値Ｊｒ，Ｇ強度変換値Ｊｇ，Ｂ強度変換値Ｊｂを求めるようになっている。
【００５１】
Ｊｒ＝ｆｒ（Ｉｒ，Ｉｇ，Ｉｂ，λｒ，λｇ，λｂ） …式（１）
Ｊｇ＝ｆｇ（Ｉｒ，Ｉｇ，Ｉｂ，λｒ，λｇ，λｂ） …式（２）
Ｊｂ＝ｆｂ（Ｉｒ，Ｉｇ，Ｉｂ，λｒ，λｇ，λｂ） …式（３）
これにより、レーザ光の波面曲率の変化に関係なく、所望の色の画像を観察者に認識させることができる。
【００５２】
以上のように、本第２実施形態の網膜走査型ディスプレイ７０によれば、上記第１実施形態の網膜走査型ディスプレイ１０と同様の効果を得ることができ、更に、強度変換部７２により出力強度のバランスを補正するようにしているため、観察者に認識させようとする色を正確に表現することができる。
【００５３】
次に、第３実施形態の画像表示装置としての画像投影装置８０について、図５を用いて説明する。
図５に示すように、第３実施形態の画像投影装置８０は、第１実施形態の網膜走査型ディスプレイ１０（図１）と比較すると、第２リレー光学系８２が、第１実施形態の第２リレー光学系３８のようにガルバノミラー３６によって走査されたレーザ光を観察者の瞳孔２に入射させるのではなく、投影面としてのスクリーン４上に走査させるようになっている点が異なっている。なお、図５において、図１に示した網膜走査型ディスプレイ１０と同じ構成要素については、同一の符号を付しているため、詳細な説明は省略する。
【００５４】
この画像投影装置８０は、曲面状のスクリーン４上にレーザ光を走査させることで画像を表示するものであり、その際、スクリーン４上でのレーザ光の波面曲率がその照射位置に関係なく常に一定となるような制御を行うようになっている。このため、本実施形態において、外部機器から画像信号供給回路４０に入力される画像信号は、スクリーン４の曲面度合いが加味された情報であり、画像信号供給回路４０では、この画像信号から、スクリーン４上でのレーザ光の波面曲率を一定にするための奥行信号が生成される。
【００５５】
以上のように、本第３実施形態の画像投影装置８０によれば、レーザ光の波面曲率を高速に変化させることができるため、曲面状のスクリーン４上の全ての場所で良好にピントを合わせることができ、その結果、高精度の画像を表示することができる。
【００５６】
なお、上記第３実施形態の画像投影装置８０では、スクリーン４の曲面度合いが加味された画像信号が外部機器から入力されるようになっているが、これに限ったものではない。例えば、外部機器からはスクリーン４の曲面度合いが加味されていない二次元画像を表す画像信号が入力されるようになっていても、画像投影装置８０が、スクリーン４の曲面度合いを認識しており、この曲面度合いに基づきレーザ光の波面曲率を変化するようになっていれば、スクリーン４の曲面度合いに応じて画像を良好に表示させることができる。そして特に、画像投影装置８０が、スクリーン４の曲面度合いを検出する検出センサを備え、この検出センサの検出値に基づきスクリーン４の曲面度合いを判断するようになっていれば、スクリーン４の曲面度合いが変化しても、画像を常に良好な状態で表示させることができる。
【００５７】
以上、本発明の一実施形態について説明したが、本発明は、種々の形態を採り得ることは言うまでもない。
例えば、上記各実施形態のレーザ可変部２０，２２，２４は、図３に示すように２つのボールレンズ６０，６２を並設した構成となっているが、これに限ったものではなく、このレーザ可変部２０，２２，２４に代えて、図６に示すようなレーザ可変部９０を用いてもよい。
【００５８】
即ち、図６に示すレーザ可変部９０は、入射したレーザ光を透過光と透過光の垂直方向に反射された反射光とに分離するビームスプリッタ９２と、ビームスプリッタ９２に反射されたレーザ光を収束するボールレンズ６０と、ボールレンズ６０に収束されたレーザ光を入射方向に反射するミラー９４とを備えている。ここで、ビームスプリッタ９２は、斜面に誘電体多層膜の施された直角プリズム２つが貼り合わされたキューブ状の形状をなしており、その斜面において、入力光の光量の約５０％を直角方向に反射し、約５０％を透過するようになっている。このため、ビームスプリッタ９２に入射したレーザ光は、ボールレンズ６０側へ反射され、ボールレンズ６０を通過後にミラー９４で反射されて再びボールレンズ６０を通過し、更にビームスプリッタ９２を通過して出射される。このため、この構成によっても、上記各実施形態のレーザ可変部２０，２２，２４と同様の効果を得ることができる。
【００５９】
また、上記各実施形態では、レーザ出力部１２，１４，１６として、出力されるレーザ光の波長を温度制御により変化させる構成（図２）が、また、レーザ可変部２０，２２，２４として、レーザ光の波面曲率をボールレンズ６０，６２の波長分散特性を利用して変化させる構成（図３）が用いられているが、これに限ったものではなく、例えば、図７に示すような構成にしてもよい。
【００６０】
即ち、図７に示すレーザ出力部１００は、相異なる固定波長のレーザ光を出射する第１出射部１０２，第２出射部１０４，第３出射部１０６，第４出射部１０８と、各出射部１０２，１０４，１０６，１０８から出射されたレーザ光をカップリング１１０，１１２，１１４，１１６を介して入力する第１入力光ファイバ１１８，第２入力光ファイバ１２０，第３入力光ファイバ１２２，第４入力光ファイバ１２４と、各入力光ファイバ１１８，１２０，１２２，１２４からのレーザ光を合成して中継用光ファイバ１２６に入力させるアレイ導波路格子型光合波器（ＡＷＧ光合波器）１２８と、各出射部１０２，１０４，１０６，１０８から出射されるレーザ光の出力強度（出射のオン・オフを含む）を制御する制御部１３０とを備えている。なお、各入力光ファイバ１１８，１２０，１２２，１２４をＡＷＧ光合波器１２８を用いることなく中継用光ファイバ１２６にそのまま接続する構成にすることも可能であるが、ＡＷＧ光合波器１２８を用いた構成の方がレーザ光を効率よく合波できるという面で有利である。また、本レーザ出力部１００では、各出射部１０２，１０４，１０６，１０８のそれぞれが、出射手段に相当し、各入力光ファイバ１１８，１２０，１２２，１２４と、ＡＷＧ光合波器１２８と、制御部１３０とが、選択手段に相当する。
【００６１】
一方、レーザ可変部１３２は、中継用光ファイバ１２６から供給されてきたレーザ光をその波長領域に応じて分岐するアレイ導波路格子型光分波器（ＡＷＧ光分波器）１３４と、ＡＷＧ光分波器１３４によって分岐された各レーザ光の通過経路となる第１出力光ファイバ１３６，第２出力光ファイバ１３８，第３出力光ファイバ１４０，第４出力光ファイバ１４２と、各出力光ファイバ１３６，１３８，１４０，１４２からカップリング１４４，１４６，１４８，１５０を介して出射されるレーザ光の各通過経路に相異なる間隔で並設された２つのレンズからなる第１固定レンズ列１５２，第２固定レンズ列１５４，第３固定レンズ列１５６，第４固定レンズ列１５８と、第１固定レンズ列１５２を通過後のレーザ光を反射させる全反射ミラー１６０と、全反射ミラー１６０からのレーザ光を通過させると共にこのレーザ光と同軸となるように第２固定レンズ列１５４を通過後のレーザ光を反射させる部分透過ミラー１６２と、部分透過ミラー１６２からのレーザ光を通過させると共にこのレーザ光と同軸となるように第３固定レンズ列１５６を通過後のレーザ光を反射させる部分透過ミラー１６４と、第４固定レンズ列１５８を通過後のレーザ光を通過させると共にこのレーザ光と同軸となるように部分透過ミラー１６４からのレーザ光を反射させる部分透過ミラー１６６とを備えている。なお、本レーザ可変部１３２では、ＡＷＧ光分波器１３４及び各出力光ファイバ１３６，１３８，１４０，１４２が、分岐手段に相当する。
【００６２】
ＡＷＧ光分波器１３４は、中継用光ファイバ１２６から供給されてきたレーザ光をその波長領域に応じた出力光ファイバ１３６，１３８，１４０，１４２へ分岐するが、この波長領域は、第１出射部１０２，第２出射部１０４，第３出射部１０６，第４出射部１０８から出射される各波長のレーザ光が、第１出力光ファイバ１３６，第２出力光ファイバ１３８，第３出力光ファイバ１４０，第４出力光ファイバ１４２へそれぞれ分岐されるような範囲に設定されている。このため、各出射部１０２，１０４，１０６，１０８から出射されるレーザ光は、それぞれ異なる固定レンズ列１５２，１５４，１５６，１５８を通過して出力されることとなる。ここで、各固定レンズ列１５２，１５４，１５６，１５８は、２つのレンズの間隔がそれぞれ異なるため、各固定レンズ列１５２，１５４，１５６，１５８を通過するレーザ光の波面曲率を、相異なる比率で変化させることとなる。したがって、制御部１３０によりレーザ光を出力する出射部１０２，１０４，１０６，１０８を切り替えることで、レーザ可変部１３２を通過後のレーザ光の波面曲率を瞬時に変化させることができる。
【００６３】
そして特に、このような構成のレーザ出力部１００及びレーザ可変部１３２では、複数の出射部１０２，１０４，１０６，１０８から異なる波長のレーザ光を同時に出射させることにより、複数種類の波面曲率のレーザ光を合成してレーザ可変部１３２から出力させることができる。このため、このレーザ出力部１００及びレーザ可変部１３２を網膜走査型ディスプレイに適用すれば、奥行き方向に距離をおいて重なった画像（例えば、ある画像の手前に半透明の画像を重ねたような画像）を観察者に認識させることができる。
【００６４】
なお、レーザ出力部１００とレーザ可変部１３２とは、この組み合わせに限ったものではなく、例えば、レーザ出力部１００と上記各実施形態のレーザ可変部２０，２２，２４とを組み合わせてもよく、また、上記各実施形態のレーザ出力部１２，１４，１６とレーザ可変部１３２とを組み合わせてもよい。
【００６５】
また、各出射部１０２，１０４，１０６，１０８から出力されたレーザ光を合成するための光導波路は、光ファイバに限ったものではない。
例えば、図８に示すレーザ出力部１７０は、各出射部１０２，１０４，１０６，１０８から出射される各レーザ光の光軸上に配置された固定ミラー１７２，１７４，１７６，１７８と、固定ミラー１７２，１７４間に設けられ、固定ミラー１７２，１７４により反射されたレーザ光の何れか一方を選択的に反射する光スイッチ１８０と、固定ミラー１７６，１７８間に設けられ、固定ミラー１７６，１７８により反射されたレーザ光の何れか一方を選択的に反射する光スイッチ１８２と、光スイッチ１８０，１８２からの各レーザ光を反射する固定ミラー１８４，１８６と、固定ミラー１８４，１８６間に設けられ、固定ミラー１８４，１８６により反射されたレーザ光の何れか一方を選択的に反射して出力する光スイッチ１８８と、各出射部１０２，１０４，１０６，１０８から出射されるレーザ光の出力強度を制御すると共に、各光スイッチ１８０，１８２，１８８の向きを制御する制御部１９０とを備えている。なお、各光スイッチ１８０，１８２，１８８は、シリコンマイクロミラーアレイで形成することにより、シリコン微細加工などの半導体プロセスによって生産することが可能となり、小型化及び高速なスイッチングを実現することができる。また、このレーザ出力部１７０では、固定ミラー１７２〜１７８，１８４，１８６と、光スイッチ１８０，１８２，１８８と、制御部１９０とが、選択手段に相当する。
【００６６】
そして、このレーザ出力部１７０では、制御部１９０が各光スイッチ１８０，１８２，１８８の向きを制御することで、レーザ出力部１７０から出力されるレーザ光を、各出射部１０２，１０４，１０６，１０８により出射される相異なる波長のレーザ光の中から選択することができる。
【００６７】
一方また、レーザ光の波長は、レーザ光の出力強度を変えることによっても変化させることができるため、出力強度を変化させることによりレーザ光の波長を変化させる制御（いわゆる注入電流制御）を行うことも可能である。
【図面の簡単な説明】
【図１】 第１実施形態の網膜走査型ディスプレイの概略構成図である。
【図２】 Ｂレーザ出力部の概略構成図である。
【図３】 Ｂレーザ可変部の概略構成図である。
【図４】 第２実施形態の網膜走査型ディスプレイの概略構成図である。
【図５】 第３実施形態の画像投影装置の概略構成図である。
【図６】 １つのボールレンズで構成した場合のレーザ可変部の概略構成図である。
【図７】 光ファイバを用いて構成した場合のレーザ出力部及びレーザ可変部の概略構成図である。
【図８】 光スイッチを用いて構成した場合のレーザ出力部の概略構成図である。
【符号の説明】
１０，７０…網膜走査型ディスプレイ、１２…Ｒレーザ出力部、１４…Ｇレーザ出力部、１６…Ｂレーザ出力部、１８…レーザ光出力部、２０…Ｒレーザ可変部、２２…Ｇレーザ可変部、２４…Ｂレーザ可変部、２６…全反射ミラー、２８，３０…部分透過ミラー、３２…ポリゴンミラー、３４…第１リレー光学系、３６…ガルバノミラー、３８，８２…第２リレー光学系、４０…画像信号供給回路、４２…波長指示部、４４…強度指示部、４６…垂直走査駆動部、４８…水平走査駆動部、５０…ＬＤチップ、５２…基板、５４…温度調節素子、５６…レンズ、５８…制御部、６０，６２…ボールレンズ、７２…強度変換部、８０…画像投影装置、９０，１３２…レーザ可変部、９２…ビームスプリッタ、９４…ミラー、１００，１７０…レーザ出力部、１０２，１０４，１０６，１０８…出射部、１１８，１２０，１２２，１２４…入力光ファイバ、１２６…中継用光ファイバ、１２８…ＡＷＧ光合波器、１３０…制御部、１３４…ＡＷＧ光分波器、１３６，１３８，１４０，１４２…出力光ファイバ、１５２，１５４，１５６，１５８…固定レンズ列、１６０…全反射ミラー、１６２，１６４，１６６…部分透過ミラー、１７２〜１７８，１８４，１８６…固定ミラー、１８０，１８２，１８８…光スイッチ、１９０…制御部[0001]
BACKGROUND OF THE INVENTION
  The present inventionLaser lightThis invention relates to a technique for changing the wavefront curvature of the.
[0002]
[Prior art]
  Traditionally,Laser lightA technique for changing the wavefront curvature of the is known.
  For example, Patent Document 1 discloses thatLaser lightAn image display device (so-called retinal scanning display) is disclosed in which an observer recognizes an image by two-dimensionally scanning and making this scanning light incident on the pupil of the viewer. In this image display device, the light enters the observer's pupil.Laser lightThe wavefront curvature is changed by wavefront curvature modulation means,Laser lightThe viewer is given the same vision as a bright spot at a distance equal to the wavefront radius of curvature in the incident direction extension, and the stereoscopic image is recognized. This wavefront curvature modulation means is applied to the surface of the piezoelectric plate that is deformed when a voltage is applied.Laser lightA reflective film that reflects the light is provided, and by applying a voltage to the piezoelectric plate,Laser lightThe wavefront curvature of.
[0003]
  Patent Document 1 states that a movable lens can be used as wavefront curvature modulation means if a low speed is allowed, and if a higher speed is required, a gradient index waveguide is used as an electro-optic effect. It is described that it is also possible to adopt a form in which the refractive index distribution shape is modulated by electrical means.
[0004]
[Patent Document 1]
        Japanese Patent No. 2874208 (2nd page, FIGS. 1 and 2)
[0005]
[Problems to be solved by the invention]
  However, using the deformation of the piezoelectric plateLaser lightIn the configuration in which the shape of the member is changed like the configuration in which the wavefront curvature is changed, it is difficult to change the wavefront curvature at high speed.
[0006]
  According to the configuration using the gradient index waveguide as described above, theoretically,Laser lightThe wavefront curvature can be changed at a high speed. However, if this configuration is to be realized with the current technology, it becomes extremely expensive, and it is difficult to adopt it in a practical sense.
[0007]
  The present invention has been made in view of these problems,Laser lightThe purpose of this is to change the wavefront curvature of.
[0008]
[Means for Solving the Problems and Effects of the Invention]
  Claim 1 made to achieve the above object.Laser lightThe irradiation deviceLaser lightAnd outputLaser lightThe wavefront curvature of the can be adjusted to the desired size,Almost the same color and different wavelengthsDuplicateNumber of laser lightsTheAs one laser beamOutput possibleLaser lightOutput means;Laser lightOutput by output meansLaser lightProvided in the passage route of theLaser lightWavefront curvature of thatLaser lightAnd a curvature variable means for changing the wavelength according to the wavelength. And booksLaser lightIn the irradiation device, it passed the curvature variable meansLaser lightIs output from the deviceLaser light(outputLaser lightAnd this outputLaser lightIn order to change the wavefront curvature of the light to a desired size, the wavelength indicating meansLaser lightOutput by output meansLaser lightThe wavelength ofInstructed by the wavelength value output to the laser beam output means.As a result, the laser light output means can be selected from a plurality of emission means that emit laser beams having different wavelengths or controlled by the emission means that can change the wavelength of the emitted laser light. Outputs laser light.
[0009]
  Like thisLaser lightThe irradiation deviceLaser lightOutput by output meansLaser lightOutput by changing the wavelength ofLaser lightA completely new configuration is adopted in which the wavefront curvature of the slab is changed to a desired size. And outputLaser lightChange the wavelength ofLaser lightVarious types of output means are used in a wide range of fields. So bookLaser lightOutput according to the irradiation deviceLaser lightCan be changed at high speedLaser lightAn output means can be used, thereby allowing outputLaser lightCan be changed at high speed.
  Also bookLaser lightIn the curvature variable means of the irradiation device,Laser lightDifferent wavefront curvaturesIn valueA plurality of lens systems to be changed are provided, and the branching means isLaser lightOutput by output meansLaser lightIs branched into one of a plurality of lens systems according to the wavelength region.The output combining means combines the laser light that has passed through the lens system.It has become so.
  For this reason, since the ratio by which each lens system changes the wavefront curvature may be a fixed value, there is no need to change the position or shape of the member, and the wavefront curvature can be changed at high speed.
[0010]
  Here, the wavelength indicating means may be, for example, an adjustment knob for increasing or decreasing the wavelength length. However, as described in claim 2, the wavelength indicating means outputsLaser lightThe wavelength to make the wavefront curvature of the target valueLaser lightIf it is instructed to output means, outputLaser lightIt is possible to control such that the wavefront curvature is set to the target value.
[0011]
[0012]
[0013]
[0014]
  On the other hand,Laser lightFor example, the output means may be configured as in claim 3 or claim 4.
[0015]
  That is, according to claim 3Laser lightIrradiation equipmentLaser lightThe output means has a wavelength according to the temperature.Laser lightTemperature-dependent emitting means is provided, and the temperature control means controls the temperature of the temperature-dependent emitting means.And outputs the laser beam from the temperature-dependent emitting means whose wavelength is changed by temperature control by the temperature control means as the one laser beam.The
  Further, according to claim 4Laser lightIrradiation equipmentLaser lightIn the output means, different wavelengthsLaser lightAre provided, and the selection means should outputLaser lightSelect from multiple emission meansOr synthesisTo becomeThe laser beam selected or synthesized by the selection means is output as the one laser beam.The
[0016]
  And in claim 3 aboveLaser lightAccording to the irradiation deviceLaser lightOutput by output meansLaser lightTherefore, it is possible to facilitate fine adjustment of the wavefront curvature.
  Further, in the above claim 4Laser lightAccording to the irradiation deviceLaser lightOutput by output meansLaser lightCan be changed at high speed.
[0017]
  By the way, outputLaser lightTo change the wavefront curvature ofLaser lightOutput by output meansLaser lightIf you change the wavelength ofLaser lightThe change in color also increases.
  Therefore, as described in claim 5, the wavelength indicating means isLaser lightOutput from output meansLaser lightThe wavelength may be changed within a range of 10 nm or less. This way,Laser lightCaused by changing the wavelength ofLaser lightThe color change can be suppressed to the extent that humans are not visually concerned.
[0018]
  Next, according to claim 6Laser lightThe irradiation deviceThe laser beam irradiation device according to any one of claims 1 to 5, wherein the wavelength is red, green, and blue.Have.
[0019]
[0020]
[0021]
  Next, the image display device according to claim 7 is directed toward the observer's pupil.Laser lightAn image is displayed on an observer's retina by irradiating with a light source, and the method according to claim 1.Laser lightAn irradiation device;Laser lightOutput by the irradiation deviceLaser lightScanning means for scanning, and from the scanning meansLaser lightAnd an optical means for directing the traveling direction toward the observer's pupil. According to this configuration,Laser lightTherefore, it is possible to display a highly accurate stereoscopic image. In particular, in claim 4 aboveLaser lightWhen using an irradiation device, output to the selection meansLaser lightBy simultaneously selecting a plurality of emitting means as the emitting means for emitting light, a plurality of different wavefront curvatures are selected.Laser lightCan be output at the same time, so that an image that overlaps with a distance in the depth direction (for example, an image in which a translucent image is superimposed in front of a certain image) can be displayed.
[0022]
  Next, an image display device according to claim 8 is provided on a projection plane.Laser light7. An image is displayed by scanning the image, and the image processing device according to any one of claims 1 to 6.Laser lightAn irradiation device;Laser lightOutput by the irradiation deviceLaser lightScanning means for scanning. According to this configuration,Laser lightSince the wavefront curvature of the lens can be changed at high speed, even when the projection distance is not constant, for example, the projection surface is a curved surface, it can be focused well in all places, and as a result, A highly accurate image can be displayed.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments to which the present invention is applied will be described below with reference to the drawings.
  First, FIG. 1 is a schematic configuration diagram of a retinal scanning display 10 as an image display apparatus according to the first embodiment.
[0024]
  The retinal scanning display 10 has an observer's pupil 2HeleIn order to make the observer recognize the image projected on the retina by making the light incident, as shown in FIG. 1, each color of red (R), green (G), and blue (B) ( A laser beam output unit 18 having an R laser output unit 12, a G laser output unit 14, and a B laser output unit 16 for outputting laser beams in each wavelength region), and each laser output unit 12 of the laser beam output unit 18, An R laser variable unit 20 and a G laser variable unit that are provided in the passage paths of the laser beams output from the laser output units 14 and 16 and change the wavefront curvatures of the laser beams output from the laser output units 12, 14, and 16, respectively. 22, the B laser variable unit 24, the total reflection mirror 26 for reflecting the laser beam after passing through the B laser variable unit 24, and the laser beam from the total reflection mirror 26 are allowed to pass and be coaxial with the laser beam. G laser The partially transmissive mirror 28 that reflects the laser light after passing through the deforming portion 22, and the laser light from the partially transmissive mirror 28 that passes through the R laser variable portion 20 and is coaxial with this laser light. A partially transmissive mirror 30 that reflects light, a polygon mirror 32 that scans the laser light synthesized by the mirrors 26, 28, and 30 in the horizontal direction, and a first direction that converges the traveling direction of the laser light scanned by the polygon mirror 32. The relay optical system 34, the galvano mirror 36 that vertically scans the laser light incident by the first relay optical system 34, and the second relay optical that causes the laser light scanned by the galvano mirror 36 to enter the pupil of the observer. And a system 38. The first relay optical system 34 is configured so that the deflecting surface 32a of the polygon mirror 32 and the deflecting surface 36a of the galvano mirror 36 are optically conjugated, and the second relay optical system 38 is configured of the galvano mirror 36. The deflecting surface 36a and the position of the observer's pupil 2 are provided so as to be optically conjugate.
[0025]
  Further, the retinal scanning display 10 receives an image signal (video signal) from an external device (not shown) such as a personal computer, and makes the observer recognize an image represented by the input image signal. An image signal supply circuit 40 for generating a depth signal L, intensity signals Ir, Ig, Ib, a vertical synchronization signal Y, and a horizontal synchronization signal X as signals, and a depth signal L from the image signal supply circuit 40. In order for the observer to recognize the depth indicated by the input depth signal L, the R laser output unit 12, the G laser output unit 14, and the B laser output unit 16 of the laser beam output unit 18 are respectively the wavelength values of the laser beams to be output. An R wavelength indication value λr, a G wavelength indication value λg, and a B wavelength indication value λb are obtained, and the wavelength indication values λr, λg, and λb are obtained as laser light output units 18 (specifically, the wavelength indication values λr, Intensity signals Ir, Ig, Ib are input from the wavelength instruction unit 42 to be output to the laser output units 12, 14, 16) corresponding to g, λb and the image signal supply circuit 40, and the input intensity signals Ir, Ig , Ib is an R intensity indication that is an intensity indication value for causing the R laser output unit 12, the G laser output unit 14, and the B laser output unit 16 of the laser beam output unit 18 to output laser light having an output intensity corresponding to the values of Ib The value Wr, the G intensity instruction value Wg, and the B intensity instruction value Wb are obtained, and the intensity instruction values Wr, Wg, Wb correspond to the laser beam output unit 18 (specifically, the intensity instruction values Wr, Wg, Wb correspond to the intensity instruction values Wr, Wg, Wb). The vertical sync signal Y is input from the intensity instruction unit 44 to be output to each of the laser output units 12, 14, 16) and the image signal supply circuit 40, and the galvano mirror 36 is synchronized with the input vertical sync signal Y. Reciprocating drive And a horizontal scanning drive unit 48 that receives the horizontal synchronization signal X from the image signal supply circuit 40 and rotationally drives the polygon mirror 32 so as to be synchronized with the inputted horizontal synchronization signal X. Yes. The intensity signals Ir, Ig, and Ib are information that expresses the balance of the RGB colors as numerical values of 0 to 255, and the intensity instruction values Wr, Wg, and Wb are, for example, 20 μW. This information directly represents the output intensity of the laser light from the output units 12, 14, and 16.
[0026]
  Here, the reason for changing the wavefront curvature of the laser beam output from each laser output unit 12, 14, 16 by each laser variable unit 20, 22, 24 in the retinal scanning display 10 will be briefly described. The light emitted from the light source is propagated as a so-called spherical wave of light traveling at the same speed and in the same phase in all directions around the light emitting point. Here, the spherical wave is projected onto the retina of the viewer with a radius of curvature that varies depending on the distance between the light emitting point and the viewer. Since the observer can feel a sense of perspective according to the radius of curvature, by changing the curvature of the spherical wave, that is, the wavefront curvature, the observer can recognize a stereoscopic image that is closer to a natural sensation. It is doing so.
[0027]
  Next, specific configurations of the laser output units 12, 14, 16 and the laser variable units 20, 22, 24 will be described. In the following description, the B laser output unit 16 and the B laser variable unit 24 will be described, but the other laser output units 12 and 14 and the laser variable units 20 and 22 have the same configuration.
[0028]
  As shown in FIG. 2, the B laser output unit 16 outputs an LD (laser diode) chip 50 that outputs laser light and changes the wavelength of the output laser light according to temperature, and a substrate on which the LD chip 50 is fixed. 52, a temperature adjusting element (in this embodiment, Peltier element) 54 that is incorporated in the substrate 52 and generates heat with a heat generation amount corresponding to an external control amount, and laser light output from the LD chip 50 is made substantially parallel light. A lens 56 for conversion and a controller 58 for controlling the output intensity of the laser light output from the LD chip 50 and the amount of heat generated by the temperature adjustment element 54 are provided.
[0029]
  The control unit 58 controls the output intensity of the laser beam output from the LD chip 50 in accordance with the B intensity instruction value Wb input from the intensity instruction unit 44. In addition, the control unit 58 controls the amount of heat generated by the temperature adjustment element 54 so that the laser light having the wavelength indicated by the B wavelength instruction value λb input from the wavelength instruction unit 42 is output from the LD chip 50. Adjust the temperature.
[0030]
  The B laser output unit 16 directly fixes the LD chip 50 to the substrate 52 in which the temperature adjustment element 54 is incorporated, so that the response of the wavelength change of the laser light to the change in the amount of heat generated by the temperature adjustment element 54 can be obtained. It is structured to be raised. Further, in the LD chip 50 of the present embodiment, the wavelength of the laser light changes at a rate of about 0.3 nm / deg.
[0031]
  On the other hand, as shown in FIG. 3, the B laser variable unit 24 passes two identical ball lenses 60 and 62 in the laser beam path at regular intervals in the passage path of the laser beam output from the B laser output unit 16. It has a configuration alongside. The ball lenses 60 and 62 are made of a material having a large wavelength dispersion characteristic. In this embodiment, S-NHP2 (trade name) which is a glass material manufactured by OHARA INC. Is used as the material. . The reason why the ball lenses 60 and 62 are used in the B laser variable section 24 is that the change in the wavefront curvature with respect to the change in the wavelength of the laser light can be increased as compared with the normal lens. Moreover, the diameter of each ball lens 60 and 62 is 5 mm, and the distance between centers of the ball lenses 60 and 62 is 5.062 mm.
[0032]
  In the B laser variable unit 24, the laser light output from the B laser output unit 16 and incident on the ball lens 60 is refracted by the ball lens 60 to become convergent light, and is focused between the ball lenses 60 and 62. After the connection, the light enters the ball lens 62 as diffused light, and is refracted and emitted by the ball lens 62. Here, if the position at which the laser beam is focused is an intermediate position between the ball lenses 60 and 62, the laser beam emitted from the ball lens 62 is in a state before entering the ball lens 60 (substantially parallel light). However, since the refractive index of the laser light when passing through the ball lenses 60 and 62 changes according to the wavelength of the laser light due to the wavelength dispersion characteristics of the ball lenses 60 and 62, the B laser When the wavelength of the laser beam output from the output unit 16 changes, the position where the laser beam is focused also moves, and the wavefront curvature of the laser beam emitted from the ball lens 62 changes. That is, the wavefront curvature of the laser light after passing through the B laser variable section 24 changes according to the wavelength of the laser light output from the B laser output section 16. Note that “the wavefront curvature of the laser light changes” means that the wavefront curvature of the laser light changes at a certain position (for example, on the retina of the observer). This means that the parallelism of the laser light changes.
[0033]
  Specifically, as shown in Table 1, the wavelength indicating unit 42 changes the B wavelength indicating value λb within a range of 0.01 μm (10 nm) from 0.455 μm to 0.465 μm. Thereby, the wavefront curvature radius of the laser light emitted from the ball lens 62 is 2.88 × 10 6.^FourIt changes from m (almost infinity) to 0.386m. Here, the change in the color of the laser beam when the wavelength of the laser beam is changed in the range of 10 nm is such that a human is not visually concerned, and thus the color of the image recognized by the observer is reduced. The change is also suppressed to the extent that the observer does not care. In Table 1, the refractive index value is a catalog value for the glass material (S-NHP2) of the ball lenses 60 and 62 of the present embodiment, and the wavefront radius of curvature is the refractive index value. (Value taking into account the shape and the like of the ball lenses 60 and 62).
[0034]
[Table 1]

  Then, the laser beam having the wavefront curvature changed after passing through the B laser variable unit 24 is projected on the retina of the viewer, so that the viewer can see the depth indicated by the depth signal L generated by the image signal supply circuit 40. Will be recognized. That is, the wavelength indicating unit 42 that has received the depth signal L from the image signal supply circuit 40 sets the wavefront curvature of the laser light after passing through the B laser variable unit 24 to a value corresponding to the depth indicated by the depth signal L. The wavelength value of the laser beam to be output by the laser output unit 16 is output to the laser beam output unit 18 as the B wavelength instruction value λb.
[0035]
  Next, a process from when the retinal scanning display 10 inputs an image signal from an external device to when an image is projected on the retina of the observer will be described.
  First, when an image signal from an external device is input to the image signal supply circuit 40, the depth signal L, the intensity signals Ir, Ig, Ib, the vertical synchronization signal Y, and the horizontal synchronization signal X are received by the image signal supply circuit 40. Generated.
[0036]
  When the depth signal L is output from the image signal supply circuit 40 to the wavelength instruction unit 42, the wavelength instruction unit 42 outputs the R wavelength instruction value λr, the G wavelength instruction value λg, and B corresponding to the depth signal L. The wavelength instruction value λb is obtained, and the wavelength instruction values λr, λg, and λb are output to the laser beam output unit 18.
[0037]
  When the intensity signals Ir, Ig, and Ib are output from the image signal supply circuit 40 to the intensity instruction unit 44, the intensity instruction unit 44 outputs the R intensity instruction value Wr corresponding to the intensity signals Ir, Ig, and Ib. The G intensity instruction value Wg and the B intensity instruction value Wb are obtained, and the intensity instruction values Wr, Wg, Wb are output to the laser beam output unit 18.
[0038]
  Then, the laser output units 12, 14, 16 of the laser beam output unit 18 are used for the wavelength instruction values λr, λg, λb from the wavelength instruction unit 42 and the intensity instruction values Wr, Wg, Wb from the intensity instruction unit 44. The laser light having a wavelength and output intensity corresponding to the laser beam is output, and each laser beam passes through the corresponding laser variable section 20, 22, 24, and the wavefront curvature is changed. They are synthesized by mirrors 28 and 30.
[0039]
  On the other hand, a vertical synchronization signal Y is output from the image signal supply circuit 40 to the vertical scanning drive unit 46, and the galvano mirror 36 is driven to reciprocate in synchronization with the vertical synchronization signal Y.
  Similarly, a horizontal synchronization signal X is output from the image signal supply circuit 40 to the horizontal scanning drive unit 48, and the polygon mirror 32 is rotationally driven in synchronization with the horizontal synchronization signal X.
[0040]
  The laser light synthesized by the total reflection mirror 26 and the partial transmission mirrors 28 and 30 is incident on the deflecting surface 32a of the polygon mirror 32, scanned in the horizontal direction by the rotational movement of the polygon mirror 32, and the first relay optical system. 34 is incident on the deflection surface 36 a of the galvanometer mirror 36. Further, it is also scanned in the vertical direction by the reciprocating motion of the galvanometer mirror 36 and is incident on the pupil 2 of the observer by the second relay optical system 38. Thus, the image projected on the retina is recognized by the observer.
[0041]
  In the retinal scanning display 10 of the first embodiment, each laser output unit 12, 14, 16 of the laser light output unit 18 isLaser lightEach of the laser variable units 20, 22, 24 corresponds to an output unit, and each of the processes performed by the wavelength instruction unit 42 on each of the laser output units 12, 14, 16 corresponds to a wavelength instruction unit. is doing. Further, the LD chip 50 corresponds to a temperature-dependent emitting unit, and the temperature adjustment element 54 and the control unit 58 correspond to a temperature control unit. And even moreTheThe LIGON mirror 32, the first relay optical system 34, and the galvanometer mirror 36 correspond to scanning means, and the second relay optical system 38 corresponds to optical means.
[0042]
  As described above, according to the retinal scanning display 10 of the first embodiment, the laser variable units 20, 22, and 22 can be changed by changing the wavelengths of the laser beams output from the laser output units 12, 14, and 16. With the configuration in which the wavefront curvature of the laser light after passing through 24 is changed, the wavefront curvature of the laser light can be changed at high speed. As a result, an observer can recognize a highly accurate stereoscopic image.
[0043]
  The laser output units 12, 14, and 16 are configured to continuously change the wavelength of the laser beam to be output, and the laser variable units 20, 22, and 24 also correspond to the wavelength of the laser beam. Therefore, since the wavefront curvature can be continuously changed, fine adjustment of the wavefront curvature of the laser light can be easily performed.
[0044]
  Furthermore, each of the laser variable sections 20, 22, and 24 has a simple configuration in which the ball lenses 60 and 62 are arranged in parallel, and thus can be realized at low cost. In particular, the use of a ball lens made of a material with a large wavelength dispersion characteristic increases the change in the wavefront curvature with respect to the change in the wavelength of the laser beam, so that the observer can recognize an image with sufficient depth. Therefore, it is possible to reduce the change width of the wavelength of the laser beam for obtaining the change width of the wavefront curvature necessary for the laser beam. As a result, it is possible to suppress the change in the color of the laser beam to the extent that the human is not concerned.
[0045]
  In addition, since each laser variable section 20, 22, 24 is provided corresponding to each of the laser output sections 12, 14, 16, the wavefront of the laser light output by each laser output section 12, 14, 16 There is no need to correct the curvature separately. That is, if the wavefront curvature of the laser beam output from each laser output unit 12, 14, 16 is changed using a common laser variable unit, each color laser beam passes through a common lens. In order to correct the deviation (chromatic aberration) generated in the degree of change of the wavefront curvature of each laser beam, a configuration for independently correcting the wavefront curvature of each laser beam output from each laser output unit 12, 14, 16 is provided. Need arises. On the other hand, the retinal scanning display according to the present embodiment does not require such a configuration.
[0046]
  Next, a retinal scanning display 70 as an image display apparatus according to the second embodiment will be described with reference to FIG.
  As shown in FIG. 4, the retinal scanning display 70 of the second embodiment includes an intensity conversion unit 72 in addition to the configuration of the retinal scanning display 10 (FIG. 1) of the first embodiment. In FIG. 4, the same components as those in the retinal scanning display 10 shown in FIG.
[0047]
  The intensity conversion unit 72 receives the intensity signals Ir, Ig, and Ib from the image signal supply circuit 40 and receives the wavelength instruction values λr, λg, and λb from the wavelength instruction unit 42. Then, the intensity conversion unit 72 obtains intensity conversion values Jr, Jg, Jb as new intensity signals based on these values, and outputs the intensity conversion values Jr, Jg, Jb to the intensity instruction unit 44.
[0048]
  Here, the reason why the intensity signals Ir, Ig, and Ib generated by the image signal supply circuit 40 in the retinal scanning display 70 are converted into the intensity conversion values Jr, Jg, and Jb by the intensity conversion unit 72 will be described.
  If the color of the laser light emitted on the retina of the observer is a constant reference color when the colors of the laser light output by the R laser output unit 12, the G laser output unit 14, and the B laser output unit 16 are constant, respectively. It is determined by the balance of the output intensity of each laser beam.
[0049]
  However, in the present retinal scanning display 70, the wavefront curvature of the laser light is changed by changing the wavelength of the laser light, so that the laser light output from each of the laser output units 12, 14, and 16 is changed. The color is not exactly constant, and as a result, the color of the combined laser light changes even if the balance of the output intensity of each laser light is constant.
[0050]
  Therefore, even if the color of the laser beam output from each laser output unit 12, 14, 16 changes, the intensity conversion unit 72 adjusts the output intensity so that the finally synthesized laser beam has a desired color. The balance is corrected. Specifically, the intensity converter 72 receives intensity signals Ir, Ig, Ib input from the image signal supply circuit 40 and each of the wavelengths input from the wavelength instruction unit 42 as shown in the following formulas (1) to (3). Based on the wavelength indication values λr, λg, and λb, the R intensity converted value Jr, the G intensity converted value Jg, B are used as corrected intensity signals for the respective colors of red (R), green (G), and blue (B). The intensity conversion value Jb is obtained.
[0051]
  Jr = fr (Ir, Ig, Ib, λr, λg, λb) (1)
  Jg = fg (Ir, Ig, Ib, λr, λg, λb) (2)
  Jb = fb (Ir, Ig, Ib, λr, λg, λb) (3)
  Thereby, an observer can recognize an image of a desired color regardless of a change in the wavefront curvature of the laser light.
[0052]
  As described above, according to the retinal scanning display 70 of the second embodiment, the same effect as that of the retinal scanning display 10 of the first embodiment can be obtained. Therefore, the color to be recognized by the observer can be accurately expressed.
[0053]
  Next, an image projection apparatus 80 as an image display apparatus according to the third embodiment will be described with reference to FIG.
  As shown in FIG. 5, in the image projection device 80 of the third embodiment, the second relay optical system 82 is different from the retinal scanning display 10 (FIG. 1) of the first embodiment in the first embodiment. Unlike the two-relay optical system 38, the laser beam scanned by the galvanometer mirror 36 is not incident on the pupil 2 of the observer, but is scanned on the screen 4 as a projection plane. . In FIG. 5, the same components as those of the retinal scanning display 10 shown in FIG.
[0054]
  The image projection device 80 displays an image by scanning a laser beam on a curved screen 4. At this time, the wavefront curvature of the laser beam on the screen 4 is always independent of the irradiation position. Control is performed so as to be constant. For this reason, in the present embodiment, the image signal input from the external device to the image signal supply circuit 40 is information in which the degree of curved surface of the screen 4 is taken into account. A depth signal for making the wavefront curvature of the laser light on 4 constant is generated.
[0055]
  As described above, according to the image projection device 80 of the third embodiment, the wavefront curvature of the laser light can be changed at high speed, so that the focus is satisfactorily achieved at all locations on the curved screen 4. As a result, a highly accurate image can be displayed.
[0056]
  In the image projection device 80 of the third embodiment, an image signal in which the degree of curved surface of the screen 4 is taken into account is input from an external device, but this is not restrictive. For example, even if an image signal representing a two-dimensional image that does not take into account the degree of curved surface of the screen 4 is input from an external device, the image projection device 80 recognizes the degree of curved surface of the screen 4. If the wavefront curvature of the laser light is changed based on the curved surface degree, an image can be displayed favorably according to the curved surface degree of the screen 4. In particular, if the image projection device 80 includes a detection sensor that detects the degree of curved surface of the screen 4 and determines the degree of curved surface of the screen 4 based on the detection value of the detection sensor, the degree of curved surface of the screen 4 is determined. Even if changes, the image can always be displayed in a good state.
[0057]
  As mentioned above, although one Embodiment of this invention was described, it cannot be overemphasized that this invention can take a various form.
  For example, the laser variable sections 20, 22, and 24 of each of the above embodiments have a configuration in which two ball lenses 60 and 62 are arranged side by side as shown in FIG. 3, but the present invention is not limited to this. Instead of the laser variable sections 20, 22, and 24, a laser variable section 90 as shown in FIG. 6 may be used.
[0058]
  That is, the laser variable section 90 shown in FIG. 6 separates the incident laser light into transmitted light and reflected light reflected in the vertical direction of the transmitted light, and the laser light reflected by the beam splitter 92. A converging ball lens 60 and a mirror 94 for reflecting the laser light converged on the ball lens 60 in the incident direction are provided. Here, the beam splitter 92 has a cube shape in which two right angle prisms each having a dielectric multilayer film are bonded to a slope, and about 50% of the amount of input light in the right angle direction on the slope. It reflects and transmits about 50%. Therefore, the laser beam incident on the beam splitter 92 is reflected toward the ball lens 60, passes through the ball lens 60, is reflected by the mirror 94, passes through the ball lens 60 again, and further passes through the beam splitter 92 and is emitted. Is done. For this reason, also by this structure, the effect similar to the laser variable parts 20, 22, and 24 of each said embodiment can be acquired.
[0059]
  Moreover, in each said embodiment, the structure (FIG. 2) which changes the wavelength of the laser beam output as a laser output part 12,14,16 by temperature control, and also as a laser variable part 20,22,24, A configuration (FIG. 3) is used in which the wavefront curvature of the laser light is changed using the wavelength dispersion characteristics of the ball lenses 60 and 62. However, the configuration is not limited to this. For example, the configuration shown in FIG. It may be.
[0060]
  That is, the laser output unit 100 shown in FIG. 7 includes a first emission unit 102, a second emission unit 104, a third emission unit 106, a fourth emission unit 108 that emit laser beams having different fixed wavelengths, and each emission unit. The first input optical fiber 118, the second input optical fiber 120, the third input optical fiber 122, the first input optical fiber 118 for inputting the laser light emitted from the 102, 104, 106, and 108 through the couplings 110, 112, 114, and 116. A four-input optical fiber 124, and an arrayed waveguide grating type optical multiplexer (AWG optical multiplexer) 128 that synthesizes the laser beams from the input optical fibers 118, 120, 122, and 124 and inputs them to the optical fiber 126 for relaying; And a control unit 130 for controlling the output intensity (including on / off of the emission) of the laser light emitted from each of the emission units 102, 104, 106, and 108. The input optical fibers 118, 120, 122, and 124 can be connected to the relay optical fiber 126 as they are without using the AWG optical multiplexer 128, but the AWG optical multiplexer 128 is used. The configuration is advantageous in that the laser beams can be combined efficiently. In the laser output unit 100, each of the emission units 102, 104, 106, and 108 corresponds to an emission unit, and each of the input optical fibers 118, 120, 122, and 124, the AWG optical multiplexer 128, and the control. The unit 130 corresponds to selection means.
[0061]
  On the other hand, the laser variable unit 132 includes an arrayed waveguide grating type optical demultiplexer (AWG optical demultiplexer) 134 that branches the laser light supplied from the relay optical fiber 126 according to its wavelength region, and AWG light. The first output optical fiber 136, the second output optical fiber 138, the third output optical fiber 140, the fourth output optical fiber 142, and the output optical fibers 136 that serve as passage paths for the respective laser beams branched by the branching filter 134. , 138, 140, 142 through the couplings 144, 146, 148, 150, the first fixed lens array 152, which is composed of two lenses arranged in parallel at different intervals on the respective passage paths of the laser light. A total reflection mirror that reflects the laser light after passing through the second fixed lens array 154, the third fixed lens array 156, the fourth fixed lens array 158, and the first fixed lens array 152; 160, a partially transmitting mirror 162 that transmits the laser light from the total reflection mirror 160 and reflects the laser light after passing through the second fixed lens array 154 so as to be coaxial with the laser light, and the partially transmitting mirror 162 The partially transmissive mirror 164 that reflects the laser light after passing through the third fixed lens row 156 and the laser light after passing through the fourth fixed lens row 158 so that the laser light passes through the third fixed lens row 156 and is coaxial with the laser light. A partial transmission mirror 166 is provided which reflects the laser light from the partial transmission mirror 164 so as to pass through and be coaxial with the laser light. In the laser variable unit 132, the AWG demultiplexer 134 and the output optical fibers 136, 138, 140, 142 correspond to branching means.
[0062]
  The AWG optical demultiplexer 134 branches the laser light supplied from the relay optical fiber 126 to output optical fibers 136, 138, 140, and 142 corresponding to the wavelength region. The laser light of each wavelength emitted from the unit 102, the second emitting unit 104, the third emitting unit 106, and the fourth emitting unit 108 is a first output optical fiber 136, a second output optical fiber 138, and a third output optical fiber. 140 and the fourth output optical fiber 142 are set in such a range as to be branched. For this reason, the laser beams emitted from the emission units 102, 104, 106, 108 pass through different fixed lens arrays 152, 154, 156, 158 and are output. Here, since each fixed lens array 152, 154, 156, 158 has a different interval between the two lenses, the wavefront curvature of the laser light passing through each fixed lens array 152, 154, 156, 158 is different from each other. Will change. Therefore, the wavefront curvature of the laser beam after passing through the laser variable unit 132 can be instantaneously changed by switching the emitting units 102, 104, 106, and 108 that output the laser beam by the control unit 130.
[0063]
  In particular, the laser output unit 100 and the laser variable unit 132 configured as described above simultaneously emit laser beams having different wavelengths from the plurality of emission units 102, 104, 106, and 108, thereby providing lasers having a plurality of types of wavefront curvatures. The lights can be combined and output from the laser variable unit 132. For this reason, when the laser output unit 100 and the laser variable unit 132 are applied to a retinal scanning display, images overlapped with a distance in the depth direction (for example, a semi-transparent image is superimposed on the front of a certain image). Image) can be recognized by an observer.
[0064]
  The laser output unit 100 and the laser variable unit 132 are not limited to this combination. For example, the laser output unit 100 and the laser variable units 20, 22, and 24 of the above embodiments may be combined. Further, the laser output units 12, 14, 16 and the laser variable unit 132 of the above embodiments may be combined.
[0065]
  Further, the optical waveguide for synthesizing the laser beams output from the respective emission units 102, 104, 106, and 108 is not limited to an optical fiber.
  For example, the laser output unit 170 shown in FIG. 8 includes fixed mirrors 172, 174, 176, and 178 arranged on the optical axis of each laser beam emitted from each of the emission units 102, 104, 106, and 108, and a fixed mirror. 172, 174, provided between the fixed mirrors 176, 178 and the optical switch 180 that selectively reflects either one of the laser beams reflected by the fixed mirrors 172, 174, by the fixed mirrors 176, 178. An optical switch 182 that selectively reflects any one of the reflected laser beams, a fixed mirror 184, 186 that reflects each laser beam from the optical switches 180, 182 and a fixed mirror 184, 186, An optical switch 188 that selectively reflects and outputs any one of the laser beams reflected by the fixed mirrors 184 and 186, and each emission And controls the output intensity of the laser light emitted from the 102, 104, and a control unit 190 for controlling the orientation of the optical switches 180,182,188. Each optical switch 180, 182, and 188 can be produced by a semiconductor process such as silicon microfabrication by being formed of a silicon micromirror array, and downsizing and high-speed switching can be realized. In the laser output unit 170, the fixed mirrors 172 to 178, 184, 186, the optical switches 180, 182, 188, and the control unit 190 correspond to a selection unit.
[0066]
  In this laser output unit 170, the control unit 190 controls the direction of each optical switch 180, 182, 188, so that the laser light output from the laser output unit 170 is output to each of the emission units 102, 104, 106, It is possible to select from laser beams of different wavelengths emitted by 108.
[0067]
  On the other hand, since the wavelength of the laser beam can also be changed by changing the output intensity of the laser beam, control (so-called injection current control) is performed to change the wavelength of the laser beam by changing the output intensity. Is also possible.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a retinal scanning display according to a first embodiment.
FIG. 2 is a schematic configuration diagram of a B laser output unit.
FIG. 3 is a schematic configuration diagram of a B laser variable unit.
FIG. 4 is a schematic configuration diagram of a retinal scanning display according to a second embodiment.
FIG. 5 is a schematic configuration diagram of an image projection apparatus according to a third embodiment.
FIG. 6 is a schematic configuration diagram of a laser variable unit configured with one ball lens.
FIG. 7 is a schematic configuration diagram of a laser output unit and a laser variable unit configured using an optical fiber.
FIG. 8 is a schematic configuration diagram of a laser output unit configured using an optical switch.
[Explanation of symbols]
  DESCRIPTION OF SYMBOLS 10,70 ... Retina scanning display, 12 ... R laser output part, 14 ... G laser output part, 16 ... B laser output part, 18 ... Laser light output part, 20 ... R laser variable part, 22 ... G laser variable part 24 ... B laser variable part, 26 ... total reflection mirror, 28, 30 ... partial transmission mirror, 32 ... polygon mirror, 34 ... first relay optical system, 36 ... galvano mirror, 38,82 ... second relay optical system, DESCRIPTION OF SYMBOLS 40 ... Image signal supply circuit, 42 ... Wavelength instruction | indication part, 44 ... Intensity instruction | indication part, 46 ... Vertical scanning drive part, 48 ... Horizontal scanning drive part, 50 ... LD chip, 52 ... Board | substrate, 54 ... Temperature control element, 56 ... Lens, 58 ... Control unit, 60, 62 ... Ball lens, 72 ... Intensity conversion unit, 80 ... Image projection device, 90,132 ... Laser variable unit, 92 ... Beam splitter, 94 ... Mirror, 100,170 ... R The output unit, 102, 104, 106, 108 ... emitting unit, 118, 120, 122, 124 ... input optical fiber, 126 ... repeating optical fiber, 128 ... AWG optical multiplexer, 130 ... control unit, 134 ... AWG light Demultiplexer, 136, 138, 140, 142 ... output optical fiber, 152, 154, 156, 158 ... fixed lens array, 160 ... total reflection mirror, 162, 164, 166 ... partial transmission mirror, 172 to 178, 184 186: Fixed mirror, 180, 182, 188 ... Optical switch, 190 ... Control unit

Claims (8)

It outputs the laser beam, the wavefront curvature of the laser beam and an adjustable laser beam irradiation device to a desired size,
A laser beam output section can output as a single laser beam to the laser light of multiple wavelengths are different shows substantially the same color,
Provided passing path of the laser beam output by the laser beam output section, and the curvature changing means for the wavefront curvature of the laser beam is varied according to the wavelength of the laser beam,
With
The curvature varying means is
A plurality of lens systems that change the wavefront curvature of the laser light to different values ;
A branching means for branching the laser beam output by the laser light output means in any of said plurality of lens systems according to the wavelength region,
Output combining means for combining the laser light that has passed through the lens system;
Includes a laser beam which the laser beam passing through the curvature varying means is output from the apparatus (hereinafter, referred to as the output laser beam.) And has been, the further the wavefront curvature of the output laser beam a desired size order to change to, the wavelength of the output laser beam by the laser beam output unit, comprising a wavelength instruction means for instructing the wavelength value to be output to the laser beam output unit, the laser beam output means, different wavelengths Outputting laser light having a wavelength indicated by the wavelength indicating means by selecting from a plurality of emitting means for emitting the laser light or controlling the emitting means capable of changing the wavelength of the emitted laser light ,
The laser beam irradiation apparatus characterized by this. In the laser beam irradiation apparatus of Claim 1,
The wavelength instruction means instructing the laser light output means a wavelength for setting a wavefront curvature of the output laser light to a target value;
The laser beam irradiation apparatus characterized by this. In the laser beam irradiation apparatus according to claim 1 or 2,
The laser beam output means includes
Temperature-dependent emission means for emitting laser light having a wavelength according to temperature; and
Temperature control means for controlling the temperature of the temperature-dependent emitting means;
Wherein the temperature control means laser light irradiation apparatus with a laser beam and wherein also be output from the laser light of the one from the temperature-dependent emission means wavelength changes with temperature control by. In the laser beam irradiation apparatus according to claim 1 or 2,
The laser beam output means includes
A plurality of emitting means for emitting laser beams of different wavelengths;
A selecting means for selecting or synthesizing the emitting means for emitting the laser beam to be output from the plurality of emitting means;
Wherein the laser beam irradiation apparatus according to claim also be output from the laser light selected or synthesized by the selection means as a laser beam of the one. In the laser beam irradiation apparatus according to any one of claims 1 to 4,
It said wavelength indicating means, altering the wavelength of the output laser beam of the laser light output means in the range below 10 nm,
The laser beam irradiation apparatus characterized by this. A laser beam irradiation device according to any one of claims 1 to 5, the wavelength is red, green, laser beam irradiation apparatus characterized by comprising three systems blue. An image display device that displays an image on an observer's retina by irradiating a laser beam toward the observer's pupil,
The laser beam irradiation apparatus according to any one of claims 1 to 6,
Scanning means for scanning the laser beam output by the laser beam irradiation device;
Optical means for directing the traveling direction of the laser light from the scanning means toward the pupil of the observer;
An image display device comprising: An image display device that displays an image by scanning a laser beam on a projection surface,
The laser beam irradiation apparatus according to any one of claims 1 to 6,
Scanning means for scanning the laser beam output by the laser beam irradiation device;
An image display device comprising:

Images