JP4046591B2

JP4046591B2 - Operation panel input device

Info

Publication number: JP4046591B2
Application number: JP2002308877A
Authority: JP
Inventors: 伸治橋井; 昌之川村; 純中村; 健二大塚
Original assignee: SMK Corp
Current assignee: SMK Corp
Priority date: 2002-10-23
Filing date: 2002-10-23
Publication date: 2008-02-13
Anticipated expiration: 2022-10-23
Also published as: JP2004147026A

Description

【０００１】
【発明の属する技術分野】
本発明は、主に家電機器へ種々の入力操作を行う為の操作パネル入力装置に関し、更に詳しくは、操作パネルに触れずに入力操作が可能な操作パネル入力装置に関する。
【０００２】
【従来の技術】
【０００３】
給湯器や洗濯機等の家電機器には、これらの機器を操作するための操作スイッチが集中して取り付けられた操作パネルが備えられている。操作者は、この操作スイッチのいずれかを指で押圧することによって、機器に対して所定の動作制御を行う。
【０００４】
しかしながら、操作スイッチを直接指で押圧して操作する構造である為、可動部品を使用せざるを得ず、その耐久性に問題があり、また、操作スイッチの表面を指が触れることによって汚れ、操作パネルの美感を損なうという問題があった。
【０００５】
このようなことから、操作パネルを直接指で触れずに所定の操作を実行することができる非接触式の操作パネル入力装置が知られている（例えば、特許文献１）。
【０００６】
【特許文献１】
特開２０００−１００２８７（第４頁、図２）
【０００７】
図１０は、この従来の操作パネル入力装置１００を示すもので、透明のアクリル板で形成された操作パネル１０１の内方に、家電機器への制御内容に対応させて複数組の光スイッチユニットＵ_１（例えば、家電機器の電源をＯＮ制御する）、Ｕ_２・・が配置されている。
【０００８】
各組の光スイッチユニットＵは、４５５Ｋ_ＨＺの固有周波数の赤外線検出信号を発光する赤外発光素子１０２と、赤外発光素子１０２から発光される赤外線検出信号を受光可能な赤外受光素子１０３とで構成されている。
【０００９】
各光スイッチユニットＵから発光される赤外線検出信号は、図１１に示すように、互いに他の光スイッチユニットＵ_１、Ｕ_２・・から発光される赤外線検出信号と重複しないようように、所定の走査周期Ｔで繰り返し赤外発光素子１０２から発光される。
【００１０】
図１０に示すように、同一の光スイッチユニットＵで対となる赤外発光素子１０２と赤外受光素子１０３は、隣り合うようにプリント配線基板１０４上に実装され、これらの光スイッチユニットＵと操作パネル１０１の間には、赤外線のみを透過させる赤外フィルタ１０５が配設されている。
【００１１】
従って、各組の赤外発光素子１０２から発光される赤外線検出信号は、その上方の赤外フィルタ１０５と操作パネル１０１を通過して外方に出力され、又、外来光の内、赤外線検出信号を含む赤外線のみが、その近傍の操作パネル１０１と赤外フィルタ１０５を透過して赤外受光素子１０３に到達する。
【００１２】
赤外受光素子１０３の出力側には、４５５Ｋ_ＨＺの固有周波数の光電変換信号を通過させるバンドパスフィルタを介して、光スイッチユニットＵへの入力操作を判定するマイコンが備えられている。従って、赤外受光素子１０３が、固有周波数の赤外線検出信号を受光した場合にのみ、その光電変換信号がマイコンへ入力される。これにより、自然光、他のリモコン送信信号などと、赤外発光素子１０２から発光された赤外線検出信号とを、受光手段１０３により識別することができる。
【００１３】
光スイッチユニットＵの近傍に、赤外線検出信号を反射させるような物体が存在しない場合には、所定の走査周期で赤外発光素子１０２から発光される赤外線検出信号を、同一光スイッチユニットＵの対となる赤外受光素子１０３が受光することはなく、マイコンに、光電変換信号が入力されない。この状態では、マイコンは、光スイッチユニットＵに対する入力操作は行われていないものと判定する。
【００１４】
一方、下方に光スイッチユニットＵ_１が配置された操作パネル１０１へ、例えば指を近づけて入力操作を行うと、赤外発光素子１０２から発光される赤外線検出信号は、操作パネル１０１の上方に接近する指で反射され、再び、操作パネル１０１と赤外フィルタ１０５を透過して、同じ光スイッチユニットＵ_１の赤外受光素子１０３に入力される。マイコンは、赤外受光素子１０３で光電変換された光電変換信号を、同じ光スイッチユニットＵ_１の赤外発光素子１０２が赤外線検出信号を発光したタイミングとほぼ同時に入力すると、その光スイッチユニットＵ_１に対して入力操作が行われたものと判定し、家電機器に対して例えば電源をＯＮとする制御信号を出力する。
【００１５】
このときに、他の光スイッチユニットＵ_２の赤外受光素子１０３においても、指で反射された赤外線検出信号を受光することがあるが、その光スイッチユニットＵ_２の赤外発光素子１０２が赤外線検出信号を発光するタイミングと異なるタイミングで、光電変換信号がマイコンに入力されるので、その光スイッチユニットＵ_２に対する入力操作とは認識しない。
【００１６】
尚、一般に、操作パネル１０１の内方には、図１２に示すように、各光スイッチユニットＵによる制御内容や操作方法若しくは家電機器の動作状態を表示する為の液晶表示パネル１０６、更にその内方に、拡散シート１０７と導光板１０８がそれぞれ積層されている。導光板１０８は、図示しない光源からの光を液晶表示パネル１０６の背面全体に導光し、液晶表示パネル１０８のバックライトとして作用するもので、また、拡散シート１０７は、操作パネル１０１の外方から光スイッチユニットＵ等が見えないように、光路を拡散するものである。
【００１７】
【発明が解決しようとする課題】
【００１８】
この操作パネル入力装置１００によれば、指が直接操作パネル１０１に触れてその表面を汚すことがなく、また、可動部品を用いないので、耐久性にすぐれたものとすることができる。
【００１９】
しかしながら、光検出信号として固有周波数の赤外線信号を用いるので、赤外フィルタ、変復調回路、バンドパスフィルタを設ける必要があり、構造上複雑になるとともに、外来光に同じ周波数の赤外線を含む場合には、入力操作と誤認識してしまう恐れがあった。
【００２０】
また、赤外発光素子１０２から発光される赤外線検出信号の発光量に比べて、指で反射され赤外受光素子１０３に到達する赤外線検出信号の受光量は、極めて微弱であるので、赤外線検出信号以外の外来光や、操作パネル入力装置１００内での散乱光の影響を受け、赤外受光素子１０３が飽和するなどして、その検出が困難となることがあった。
【００２１】
例えば、マイコンで光電変換信号の入力で、光スイッチユニットＵに対する入力操作と判定する際には、光電変換信号、すなわち赤外受光素子１０３で受光する赤外線検出信号のレベルを、所定の入力しきい値と比較して入力操作と判定するが、外来光の変動や内部の散乱光の変動による影響が無視できないので、赤外線検出信号の入力のみを正確に判定することができなかった。
【００２２】
また、赤外受光素子１０３で受光する受光量は、上述のように一時的な外来光の変化に限らず、赤外線検出信号の光路に介在する操作パネル１０１、液晶表示パネル１０６、拡散シート１０７、導光板１０８などが汚れたり、劣化する等の経年変化によっても変化し、赤外線検出信号の増幅率を固定させ所定のしきい値と比較していると、全く入力操作を判定しなくなったり、逆に常時入力操作と判定してしまうという誤判定の原因となっていた。
【００２３】
更に、従来の操作パネル入力装置１００では、直接操作パネル１０１に触れることなく入力操作そのものを判定できるが、入力操作と入力操作解除のタイミングなど入力操作状態を更に詳細に判別することはできなかった。
【００２４】
本発明は、このような従来の問題点を考慮してなされたものであり、外来光や内部の散乱光が一時的に変化しても正確に入力操作を判定できる操作パネル入力装置を提供することを目的とする。
【００２５】
また、経年変化により赤外線検出信号の到達量が変化しても、正確に入力操作を判定することができる操作パネル入力装置を提供することを目的とする。
【００２６】
更に、入力操作状態を詳細に判別することができる操作パネル入力装置を提供することを目的とする。
【００２７】
【課題を解決するための手段】
【００２８】
請求項１の操作パネル入力装置は、少なくとも一部が光透過部となった操作パネルと、各光スイッチユニットＳＷが、操作パネルの内方に配置され、操作パネルの光透過部から外方へ光検出信号を発光する発光手段と、光透過部の外方で反射された光検出信号を受光可能な受光手段とを、対として有する複数の光スイッチユニットＳＷと、各光スイッチユニットＳＷの発光手段に対し、他の光スイッチユニットＳＷの発光手段から発光される光検出信号と重複しないように、少なくとも入力操作時間より短い走査周期で光検出信号を繰り返し発光させる発光制御手段と、発光手段が光検出信号を発光する走査周期に同期させて、同一の光スイッチユニットＵで対となる受光手段に対し受光量を検出させる受光制御手段と、受光手段が検出した受光量を、各光スイッチユニットＵの受光手段毎に一次記憶する受光量記憶部と、光スイッチユニットＵの発光手段が光検出信号を発光した際の対となる受光手段が検出した受光量から、前記光スイッチユニットＵに対する入力操作状態を判定する入力判定手段とを備えた操作パネル入力装置であって、受光量記憶部は、発光手段が光検出信号を発光する発光期間に、対となる受光手段が検出した発光時受光量を一次記憶し、入力判定手段は、光スイッチユニットＵの受光手段が新たに検出した発光時受光量と、その受光手段について受光量記憶部で一次記憶された発光時受光量とから、当該光スイッチユニットＵに対する入力操作状態を判定することを特徴とする。
【００２９】
指などの操作体により反射し受光手段に達する光検出信号は、操作体が光スイッチユニットＵに接近するほど増加し、離れると減少するので、発光手段が光検出信号を発光する走査周期に同期して受光手段が受光する発光時受光量は、操作体との距離で増減する。
【００３０】
従って、受光量記憶部で一次記憶される発光時受光量と、新たに検出される発光時受光量とを比較すれば、操作体との距離の変化を検出することができ、入力操作状態を判定できる。
【００３１】
一方、外来光、内部散乱光などの経年変化による光量変化は、受光量記憶部で一次記憶される発光時受光量と新たに検出される発光時受光量のいずれにも等しく影響し、その受光量の差には表れないので、入力操作状態のみを判定することができる。
【００３２】
また、外来光、内部散乱光の一時的な光量変化があっても、入力操作と同様に変化することは希で、同様に受光量記憶部で一次記憶される発光時受光量と新たに検出される発光時受光量の差には表れないので、入力操作状態のみを判定できる。
【００３３】
また、請求項２の操作パネル入力装置は、入力判定手段が、光スイッチユニットＵの受光手段が新たに検出した発光時受光量が、その受光手段について受光量記憶部で一次記憶された発光時受光量と比較して、所定の入力しきい値を越えて増加したときに、当該光スイッチユニットＵに対する入力操作と判定することを特徴とする。
【００３４】
操作体が光スイッチユニットＵに接近すると、操作体で反射し受光手段に到達する光検出信号が増加し、その結果、新たに検出される発光時受光量は、受光量記憶部で一次記憶される発光時受光量に比べて増加するので、所定の入力しきい値と比較することにより、入力操作のタイミングまで、入力操作を正確に判定できる。
【００３５】
また、請求項３の操作パネル入力装置は、発光制御手段が、全ての光スイッチユニットＵの発光手段から光検出信号を発光させない消灯期間を、少なくとも一走査周期内に設定するとともに、受光制御手段は、少なくともいずれかの光スイッチユニットＵの受光手段に対し消灯期間中の消灯時受光量を検出させ、受光手段が検出した消灯時受光量が、所定の消灯しきい値を越えたときに、全ての光スイッチユニットＵについての入力判定手段による入力操作の判定を、一定期間無効とすることを特徴とする。
【００３６】
受光手段が検出する消灯時受光量には、光検出信号が含まれないので、入力操作とは無関係な外来光及び内部散乱光の光量が表れる。従って、消灯時受光量が消灯しきい値を越えて増加したときには、入力操作と無関係な外来光及び内部散乱光による光量の増加とみなすことができ、これらの増加により発光時受光量が増加し入力操作と判定しても、判定を一定期間無効とすることで、機器の誤動作を防止できる。
【００３７】
一時的な光量変化に起因する誤判定を、特に別の入力操作認識手段を併用せずに確実に防止できる。
【００３８】
また、請求項４の操作パネル入力装置は、発光制御手段が、全ての光スイッチユニットＵの発光手段から光検出信号を発光させない消灯期間を、少なくとも一走査周期内に設定するとともに、受光制御手段は、少なくともいずれかの光スイッチユニットＵの受光手段に対し消灯期間中の消灯時受光量を検出させ、受光量記憶部は、消灯期間中に受光手段が検出した消灯時受光量を、発光時受光量とともに一次記憶し、受光手段が新たに検出した消灯時受光量が、その受光手段について受光量記憶部で一次記憶された消灯時受光量と比較して、所定の環境しきい値を越えたときに、全ての光スイッチユニットＵについての入力判定手段による入力操作の判定を、一定期間無効とすることを特徴とする。
【００３９】
消灯時受光量の一時的な変化には、光検出信号による影響や外来光及び内部散乱光の経年変化による光量変化は表れない。従って、新たに検出される消灯時受光量が受光量記憶部で一次記憶される消灯時受光量に比べて、所定の環境しきい値を越えて増加したときには、外来光及び内部散乱光の一時的な増加とみなすことができ、これらの増加により発光時受光量が増加し入力操作と判定しても、判定を一定期間無効とすることで、機器の誤動作を防止できる。
【００４０】
特に別の入力操作認識手段を併用せずに、また、経年変化で外来光及び内部散乱光の光量が変化しても、一時的な光量変化に起因する誤判定を確実に防止できる。
【００４１】
また、請求項５の操作パネル入力装置は、操作パネルに対する接触を検知する接触検知手段が操作パネルに配置され、入力判定手段が入力操作と判定した前後所定の推定操作期間内に、接触検知手段から接触検知信号が入力されることを条件に、当該光スイッチユニットＵに対する入力操作の判定を有効とすることを特徴とする。
【００４２】
操作パネルに対する接触を条件に、入力操作の判定を有効とするので、入力操作と同様の外来光、内部散乱光の一時的な光量変化が発生し、入力操作と判定した場合であっても、入力操作に従った命令が実行されず、機器の誤動作を確実に防止できる。
【００４３】
操作体の接近による入力操作の判定と操作パネルへの接触の時間差は、通常の入力操作から推定される推定操作期間以内であるので、通常の入力操作であれば、入力操作の判定と接触検知信号の出力に時間差が生じても、入力操作の判定が有効とされる。
【００４４】
また、請求項６の操作パネル入力装置は、入力判定手段が、光スイッチユニットＵの受光手段が新たに検出した発光時受光量が、その受光手段について受光量記憶部で一次記憶された発光時受光量と比較して、所定の解除しきい値を越えて減少したときに、当該光スイッチユニットＵに対する入力操作の解除と判定することを特徴とすることを特徴とする。
【００４５】
光スイッチユニットＵに接近していた操作体が離間すると、操作体で反射し受光手段に到達する光検出信号が減少し、その結果、新たに検出される発光時受光量は、受光量記憶部で一次記憶される発光時受光量に比べて減少するので、所定の解除しきい値と比較することにより、入力操作解除のタイミングを含む入力操作状態を正確に判定できる。
【００４６】
従って、通常の入力操作の際のみならず、入力操作解除の際にも、異なる制御内容を光スイッチユニットに対して入力できる。
【００４７】
また、請求項７の操作パネル入力装置は、受光手段が、発光手段が光検出信号を発光する走査周期に同期して受光量を検出する期間内に、複数回受光量を検出し、その平均値を受光手段が検出した受光量とすることを特徴とする。
【００４８】
受光手段は、走査周期毎に一度検出する受光量を、その検出期間内に複数回検出した受光量の平均値から求めるので、検出異常値が発生しても、受光量への影響が少なく、誤判定が減少する。
【００４９】
【発明の実施の形態】
以下、本発明に係る操作パネル入力装置１の一実施の形態を、図１乃至図７で説明する。
【００５０】
図１は、操作パネル入力装置１の斜視図で、家電機器であるユニットバスに付属する給湯器（図示せず）に備えられるものである。本発明に係る操作パネル入力装置は、防水性が求められる洗濯機、風呂の給湯器などに特に適しているが、音響機器、空調機器など他の電気機器を制御する入力装置としてこれらに付属して備えるものでもよい。
【００５１】
操作パネル入力装置１は、外方（図２において上方側）から、操作パネルとなる矩形の透明アクリル板３、液晶表示パネル４、バックライトパネル７、反射板９、プリント配線基板１３が積層して配置されたもので、これらは、積層された状態で互いの対向面が貼り付けられ、合成樹脂製のケース２内に収容されている。
【００５２】
ケース２は、外方に開口する枡形の基台２ａと、枡形周囲に嵌合し、枡形の上方に固定枠２２が突き出た押さえカバー２ｂとからなり、両者のフランジ部に挿通させる取り付けネジ２３により一体化される。
【００５３】
ケース２と透明アクリル板３との間には、接着剤、粘着剤等が塗布され、操作パネル入力装置１内に水滴、埃等が侵入しないようになっている。
【００５４】
透明アクリル板３の周囲に固定枠２２の厚み分の段差を設けることにより、透明アクリル板３とその周囲のケース２の表面は、同一平面上に整列する。
【００５５】
液晶表示パネル４は、給湯器に対して入力操作を行う制御内容と、給湯器の動作に関する所定の表示を、透明アクリル板３を通して表示するもので、図１に示す給湯器では、主電源の入力、給湯動作のスタート、追いだきの選択等の入力操作を示す表示３０ａ、３０ｂ、３０ｃ・・が、矩形枠で表示した操作エリア３０Ａ、３０Ｂ、３０Ｃ・・とともに表示される。また、この表示では、浴槽内への給湯量３１、給湯温度３２が表示されている。
【００５６】
この液晶表示パネル４による表示は、図示しない液晶ドライバーの制御により、表示されるもので、操作エリアと入力操作を示す表示３０の位置と数、及びその他の表示は、給湯器の動作状態に応じて可変するようになっている。
【００５７】
バックライトパネル７は、液晶表示パネル４の表示を内方から照光するもので、その端面に配置されるバックライト光源４０（図３参照）からのバックライト光を、その内部に導光している。バックライトパネル７は、表面（液晶表示パネル４との対向面）に拡散シート７Ａが貼り付けられた透明なアクリル板で形成され、また、背面側には、対向面を白色とした反射板９が配置されるので、バックライト光源から発光されるバックライト光は、バックライトパネル７の内部で、散乱しながら外方に導光される。これにより、透明アクリル板３の外方からは、特定のバックライト光源は確認されず、あたかも液晶表示パネル４による表示の背景全体がバックライト光により照光されたように見える。
【００５８】
本実施例では、バックライトパネル７とバックライト光源４０は、操作エリア３０毎にしきり板３３により区切られ、操作エリア３０の背面を、異なる光源で照光するようになっている。
【００５９】
反射板９は、上述のように表面に白色の塗料を塗布することにより、バックライトパネル７との対向面を白色とし、バックライト光を下方に逃げないようにバックライトパネル７内に反射させている。白色とするので、バックライト光を所定の色彩に着色すれば、液晶表示パネル４の背景は、その色彩に変化したように目視される。反射板９には、後述する発光素子５ａの図３において上方（表面側）に出力側小孔３４が、受光素子６ａの上方に入力側小孔３５が穿設されている。これらの小孔３４、３５は、例えば、内径が１乃至１．５ｍｍ程度の小孔であり、また、バックライトパネル７の表面側の拡散シート７Ａにより光路が散乱されるので、透明アクリル板３の外方からは、目視されない。
【００６０】
反射板９の背面側に取り付けられるプリント配線基板１３には、操作パネル３に表示される操作エリア３０Ａ、３０Ｂ、３０Ｃ・・のそれぞれに対応させて光スイッチユニットＵ_１、Ｕ_２、Ｕ_３、・・が配置されている（図４参照）。各光スイッチユニットＵは、赤外発光素子５ａを有する発光手段５と、赤外発光素子５ａから発光される赤外光検出信号を受光可能な赤外受光素子６ａを有する受光手段６とを、対として構成されている。本実施の形態では、赤外発光素子５ａとして赤外発光ダイオードを、赤外受光素子として、ピンフォトダイオードをそれぞれ用いている。
【００６１】
図３に示すように、同一光スイッチユニットＵの赤外発光素子５ａと赤外受光素子６ａは、プリント配線基板１３に穿設された出力孔３６と入力孔３７内に、それぞれの発光面と受光面を臨ませて、プリント配線基板１３の背面側に実装されている。尚、赤外受光素子６ａの受光面には、赤外光検出信号の赤外線のみを透過させる赤外フィルタ８が形成されている。
【００６２】
出力孔３６と入力孔３７は、その表面側に積層された反射板９の出力側小孔３４と入力側小孔３５の内径よりやや大きい内径で、それぞれ出力側小孔３４と入力側小孔３５に同一軸線上に連通するもので、これにより、各光スイッチユニットＵの赤外発光素子５ａから発光される赤外光検出信号は、出力孔３６と出力側小孔３４を通過して、透明アクリル板３から外方に放射され、又、透明アクリル板３の外方から受ける光は、入力側小孔３５と入力孔３７を通過し、更に赤外フィルタ８を通過することにより、赤外光検出信号を含む赤外線が赤外受光素子６ａに入力される。
【００６３】
図４は、本実施の形態に係る操作パネル入力装置１の各回路構成を示すブロック図であり、以下、このブロック図に沿って操作パネル入力装置１をその作用とともに説明する。
【００６４】
各光スイッチユニットＵ_１、Ｕ_２、Ｕ_３の赤外発光素子５ａは、それぞれマイコン１０によって接続制御されるＬＥＤマルチプレクサ１６に接続し、発光制御手段として作用するマイコン１０により制御される発光タイミングで赤外光検出信号を発光する。すなわち、図５に示すように、各スイッチユニットＵ_１、Ｕ_２、Ｕ_３の赤外発光素子５ａは、前後に０．５ｍｓｅｃの消灯期間ｔｏｆｆをおいて０．５ｍｓｅｃの発光期間ｔｏｎ、他の赤外発光素子５ａと重複しないタイミングで赤外光検出信号を発光するもので、前後の消灯期間ｔｏｆｆには、いずれの赤外発光素子５ａからも赤外光検出信号を発光しない。
【００６５】
発光制御は、全ての赤外発光素子５ａについて発光制御した後再び繰り返され、その一走査周期Ｔは、入力操作に要する時間に比べて短い時間に設定される。操作者が入力操作に要する時間は、個人差があるが経験的に５０ｍｓｅｃから２００ｍｓｅｃと推定し、ここでは５０ｍｓｅｃより短い１５ｍｓｅｃとしている。
【００６６】
一方、各光スイッチユニットＵ_１、Ｕ_２、Ｕ_３の赤外発光素子５ａのそれぞれについて対となる赤外受光素子６ａは、マイコン１０によって接続制御されるＰｄマルチプレクサ１７に接続し、受光制御手段としても作用するマイコン１０で制御される後述の受光タイミングで受光する。
【００６７】
Ｐｄマルチプレクサ１７の出力は、増幅回路１８を介してマイコン１０のＡ／Ｄコンバータ１９に接続されている。従って、赤外受光素子６ａがマイコン１０で制御される受光タイミングで検出する受光量は、増幅回路１８で増幅された後、Ａ／Ｄコンバータ１９でＡ／Ｄ変換された後、マイコン１０に入力される。
【００６８】
この受光タイミングは、発光素子５ａを発光制御する走査周期Ｔに同期するもので、それぞれ対となる赤外受光素子６ａ毎にその受光タイミングが設定される。ここでは、図５に示す各スイッチユニットＵ_１、Ｕ_２、Ｕ_３の赤外発光素子５ａを発光させている発光期間ｔｏｎ毎に、受光量を検出している。
【００６９】
図６は、この各発光期間ｔｏｎにおいて、受光量を検出する詳細を示すもので、各発光期間ｔｏｎのそれぞれで４回割込処理を行って（図中１２から１５の割込時間）、Ａ／Ｄコンバータ１９へその時の受光量を読み込んでいる。
【００７０】
マイコン１０では、発光期間ｔｏｎにＡ／Ｄコンバータ１９から読み込んだ４回の受光量を平均して、新たに検出された発光時受光量Ｌｏｎ（ｃ）とする。このように、複数回検出した受光量を平均することにより、１回の検出に誤差が生じても、マイコン１０へ出力される受光量への影響が減じられる。発光時受光量Ｌｏｎ（ｃ）は、マイコン１０において後述の発光時受光量Ｌｏｎ（ｏ）と比較されるとともに、スイッチユニットＵ毎に、マイコン１０に接続される４段からなるシフトレジスタ２１の最下段に記憶される。
【００７１】
同様の処理は、各スイッチユニットＵ_１、Ｕ_２、Ｕ_３について走査周期Ｔ毎に繰り返され、新たに検出された発光時受光量Ｌｏｎ（ｃ）がシフトレジスタ２１の最下段に記憶されるとともに、各段に記憶された受光量は、順次上位段に移される。その結果、特定のスイッチユニットＵについて、シフトレジスタ２１の最上位段に記憶された発光時受光量Ｌｏｎ（ｏ）は、同一スイッチユニットＵについての新たな受光量検出時の４Ｔ時間前、つまり６０ｍｓｅｃ前に検出した受光量を表すものとなる。
【００７２】
図７は、特定のスイッチユニットＵに対して、操作体である指１１を接近させた後離間させる入力操作状態について、各走査周期Ｔ毎のマイコン１０に入力される発光時受光量Ｌｏｎを実線で結び、発光時受光量Ｌｏｎの変化を表したグラフである。
【００７３】
同図のＴ１乃至Ｔ２時は、入力操作前の待機状態であり、指１１がスイッチユニットＵから離間しているので、赤外受光素子６ａは、外来光と内部で散乱する赤外光検出信号を受光し、発光時受光量Ｌｏｎが１Ｖとなっている。
【００７４】
この待機状態からの入力操作で指１１を接近させると、指１１で反射される赤外光検出信号が徐々に増加して発光時受光量Ｌｏｎが増加し、最もスイッチユニットＵへ接近させたＴ７時で約１．５Ｖのピークに達する。
【００７５】
その後、指１１を離間させていくと、反射される赤外光検出信号が徐々に減少して発光時受光量Ｌｏｎも減少し、Ｔ１２時で待機状態約の１Ｖに戻る。
【００７６】
本実施の形態では、指１１の接離に応じてこのように変化する発光時受光量Ｌｏｎから入力操作状態を検出するもので、マイコン１０で、新たに検出した発光時受光量Ｌｏｎ（ｃ）を、シフトレジスタ２１の最上位段に記憶された発光時受光量Ｌｏｎ（ｏ）と比較して、所定の入力しきい値、ここでは０．３ｖを越えて増加したときに、入力操作と判定する。
【００７７】
例えば、図７において、Ｔ５時の発光時受光量Ｌｏｎ（ｃ）は１．２５Ｖ、４Ｔ時間前の発光時受光量Ｌｏｎ（ｏ）は１Ｖであるので、その差は入力しきい値を越えず、続くＴ６時に、発光時受光量Ｌｏｎ（ｃ）が１．４Ｖ、４Ｔ時間前のＴ２時発光時受光量Ｌｏｎ（ｏ）が１Ｖであるので、入力しきい値０．３Ｖを越え、入力操作と判定される。
【００７８】
また、マイコン１０で、新たに検出した発光時受光量Ｌｏｎ（ｃ）を、シフトレジスタ２１の最上位段に記憶された発光時受光量Ｌｏｎ（ｏ）と比較して、所定の解除しきい値、ここでは０．３ｖ以上減少したときに、入力操作の解除と判定する。
【００７９】
例えば、図７において、Ｔ１０時の発光時受光量Ｌｏｎ（ｃ）は１．３Ｖ、４Ｔ時間前の発光時受光量Ｌｏｎ（ｏ）は１．４Ｖであるので、解除しきい値は越えず、続くＴ１１時に、発光時受光量Ｌｏｎ（ｃ）が１．１Ｖ、４Ｔ時間前のＴ７時発光時受光量Ｌｏｎ（ｏ）が１．５Ｖであるので、解除しきい値０．３Ｖを越え、入力操作の解除と判定される。
【００８０】
マイコン１０では、上記入力操作及び入力操作の解除の判定を、各スイッチユニットＵ_１、Ｕ_２、Ｕ_３毎に、新たに検出した発光時受光量Ｌｏｎ（ｃ）とシフトレジスタ２１から読み出した発光時受光量Ｌｏｎ（ｏ）と比較して行う。
【００８１】
マイコン１０において、特定のスイッチユニットＵに対する入力操作と判定すると、そのスイッチユニットＵについて対応づけられた命令を給湯器に対して実行する。例えば、主電源の入力の入力操作を示す表示３０ａを表示した操作エリア３０Ａの下方に配置されたスイッチユニットＵ_１に対して入力操作と判定すると、給湯器の電源がＯＮとなる。
【００８２】
また、本実施の形態では、入力操作の解除のタイミングを含む各スイッチユニットＵ毎の入力操作状態を判定できるので、入力操作の解除の判定で別の命令を出力したり、入力操作と入力操作の解除を判定した時間間隔で、入力操作の判定を確定させるなどその判定結果を種々の用途に利用できる。
【００８３】
この第１実施の形態では、経年変化や外来光が徐々に変化する影響を受けて、赤外受光素子６ａが受光する発光時受光量Ｌｏｎのレベルが徐々に変化する場合であっても、入力操作若しくは入力操作の解除の判定において比較する発光時受光量Ｌｏｎ（ｃ）と発光時受光量Ｌｏｎ（ｏ）のいずれもその影響を受けるので、その差には表れず、これらの変化があっても正確に入力操作状態を判定できる。
【００８４】
しかしながら、この第１の実施の形態では、室内のカーテンが開けられたり、照明が点灯される、虫などが接近するなどの種々の原因で、赤外受光素子６ａに到達する外来光や内部散乱光が一時的に変化することがあり、これらの変化が希に入力操作による光量変化と同様に増加する場合には、入力操作と誤判定する恐れがある。
【００８５】
図８は、このような原因で、特定のスイッチユニットＵに対して入力操作を行わない場合であっても、入力操作と同様に発光時受光量Ｌｏｎが増加する変化を表したグラフである。図８では、外来光や内部散乱光が急激に増加することにより、指１１を接近させないにもかかわらず、Ｔ６時に、４Ｔ時間前の１Ｖから発光時受光量Ｌｏｎ（ｃ）が１．４Ｖに達し、入力しきい値０．３Ｖを越え、入力操作と誤判定される。
【００８６】
以下に説明する第２の実施の形態は、このように誤判定するような状態を検出し、一定期間入力操作の判定を無効とし、家電機器などの被制御機器の誤動作を防止するものである。
【００８７】
この第２実施の形態では、受光制御手段とし作用するマイコン１０が、第１実施の形態で、図５に示す各スイッチユニットＵ_１、Ｕ_２、Ｕ_３の赤外発光素子５ａを発光させている期間ｔｏｎ毎に加えて、更に、その直前の消灯期間ｔｏｆｆにおいても受光量を検出するものである。
【００８８】
消灯期間ｔｏｆｆにおいて受光量を検出する詳細は、発光期間ｔｏｎにおける検出と同様で、図６に示すように、各消灯期間ｔｏｆｆのそれぞれで４回割込処理を行って（消灯期間ｔｏｆｆでは、図中４から７の割込時間）、Ａ／Ｄコンバータ１９へその時の受光量を読み込む。
【００８９】
マイコン１０では、消灯期間ｔｏｆｆにＡ／Ｄコンバータ１９から読み込んだ４回の受光量を平均して、新たに検出された消灯時受光量Ｌｏｆｆ（ｃ）とする。消灯時受光量Ｌｏｆｆ（ｃ）を検出するにあたっても、同様に複数回検出した受光量を平均し、１回の検出誤差による検出値への影響を減じている。消灯時受光量Ｌｏｆｆ（ｃ）は、発光時受光量Ｌｏｎ（ｃ）と同様に、スイッチユニットＵ毎にシフトレジスタ２１の最下段に記憶され、新たに検出された消灯時受光量Ｌｏｆｆ（ｃ）がシフトレジスタ２１の最下段に記憶される毎に順次上位段に移される。
【００９０】
マイコン１０では、各スイッチユニットＵについて、新たに検出された消灯時受光量Ｌｏｆｆ（ｃ）と、シフトレジスタ２１の最上位段に記憶された消灯時受光量Ｌｏｆｆ（ｏ）、つまり４Ｔ時間（６０ｍｓｅｃ）前に検出した消灯時受光量Ｌｏｆｆ（ｏ）とを比較し、外来光と内部散乱光の異常増加を検出する。
【００９１】
すなわち、新たに検出された消灯時受光量Ｌｏｆｆ（ｃ）が、その４Ｔ時間前に検出した消灯時受光量Ｌｏｆｆ（ｏ）に比べて、所定の環境しきい値、ここでは０．３ｖを越えて増加したときには、外来光と内部散乱光の異常増加と判定し、所定期間（例えば数秒）全てのスイッチユニットＵについての入力操作の判定を無効とする。従って、特定のスイッチユニットＵが発光時受光量Ｌｏｎの増加から入力操作と判定しても、その判定が無効とされ、家電機器などで意図しない命令が実行されることがない。
【００９２】
これを消灯時受光量Ｌｏｆｆの変化を破線で結び表示した図８を用いて説明すると、Ｔ１時の発光時受光量Ｌｏｎ（ｃ）が外来光と赤外線検出信号を含む内部散乱光を受光して１Ｖであるのに対し、Ｔ１時（正確には、その０．５ｍｓｅｃ前）の消灯時受光量Ｌｏｆｆ（ｃ）は、赤外線検出信号による内部散乱光を含まないので、やや低い０．８Ｖとなっている。
【００９３】
カーテンなどがひかれて入力操作と同じ程度に外来光や内部散乱光（以下、単に外来光と記述して説明する）が増加すると、発光時受光量Ｌｏｎ（ｃ）とともに消灯時受光量Ｌｏｆｆ（ｃ）も増加する。これによりＴ６時に、発光時受光量Ｌｏｎ（ｃ）が４Ｔ時間前の発光時受光量Ｌｏｎ（ｏ）と比較して入力しきい値０．３Ｖを越えて増加し、入力操作と判定されるが、Ｔ６時の消灯時受光量Ｌｏｆｆ（ｃ）も、外来光などの増加により４Ｔ時間前の消灯時受光量Ｌｏｆｆ（ｏ）から環境しきい値０．３Ｖを越えて増加するので、前記入力操作の判定は無効とされる。
【００９４】
一方で、入力操作の状態を示す図７において、消灯時受光量Ｌｏｆｆの変化を破線で結び表示するように、外来光の異常増加がなければ、入力操作を行う指１１で外来光が遮られるので、消灯時受光量Ｌｏｆｆはむしろ減少し、その増加が環境しきい値を越えることはないので、入力操作の判定は有効に保たれる。
【００９５】
尚、同図に示すように、指１１を離間させる際に、消灯時受光量Ｌｏｆｆが一時的に増加するが、その増加分は環境しきい値を越えるものではなく、更に、発光時受光量Ｌｏｎが減少している間には、消灯時受光量Ｌｏｆｆの変化を環境しきい値と比較しないという方法を採用してもよい。
【００９６】
尚、入力しきい値と環境しきい値は、必ずしも同じ値である必要はなく、また、外来光の異常増加があっても、同時にそれぞれのしきい値を越えるものではないので、入力しきい値を越えた前後例えば２Ｔ時間（３０ｍｓｅｃ）以内に環境しきい値を越えた場合であっても、入力操作の判定を無効とすることが望ましい。
【００９７】
また、外来光の異常増加は、全てのスイッチユニットＵに対して等しく影響するので、必ずしも全てのスイッチユニットＵについて消灯時受光量Ｌｏｆｆを検出する必要はない。
【００９８】
また、上記第２の実施の形態では、消灯時受光量Ｌｏｆｆ（ｃ）をスイッチユニットＵ毎にシフトレジスタ２１に一次記憶するものであるが、走査周期Ｔ毎に検出される消灯時受光量Ｌｏｆｆ（ｃ）を、固定値である消灯しきい値と比較し、消灯しきい値を越えた場合に、外来光の異常増加と判定し、所定期間全てのスイッチユニットＵの入力操作の判定を無効としてもよい。消灯しきい値は、例えば、外来光の異常と予測される１．２Ｖ等の絶対値で定めても、入力操作を行わない待機状態での消灯時受光量Ｌｏｆｆに対して例えば＋０．３Ｖのように定めてもよい。
【００９９】
図９は、第１の実施の形態の一部を改良し、外来光の異常増加があっても入力操作を正確に判定する第３の実施の形態に係る操作パネル入力装置５０示すブロック図であり、図４と比較して明らかなように、操作パネルとなる透明アクリル板３の直交するＸ、Ｙ方向の周縁に沿って圧電基板１２Ａ、１２Ｂを固着したものである。
【０１００】
本実施の形態では、圧電基板１２Ａ、１２Ｂによる圧電効果を利用（機械的歪みから発生する電圧信号を利用）して、操作パネル３に対する接触検知手段とするもので、透明アクリル板３に操作体である指１１を触れると、透明アクリル板３に発生する歪みが周縁に固着された圧電基板１２Ａ、１２Ｂに伝達され、圧電基板１２Ａ、１２Ｂが撓むことにより電圧信号が発生するので、この電圧信号を接触検知信号とするものである。
【０１０１】
圧電基板１２Ａ、１２Ｂは、透明アクリル板３の周縁に取り付けられるので、液晶表示パネル４の表示領域を狭めることがなく、外部からは見えない周縁に取り付けることができる。しかしながら、圧電基板１２Ａ、１２Ｂの取付位置は、透明アクリル板３への接触を検出できれば、いずれの位置に固着するものであってもよい。
【０１０２】
また、圧電基板１２Ａ、１２Ｂを固着した本実施の形態では、透明アクリル板３への接触による歪みを圧電基板１２Ａ、１２Ｂに伝達する必要があるので、透明アクリル板３の変形が拘束されないように、ケース２との間に、合成ゴムからなる緩衝板、粘着剤などを介在させる必要がある。
【０１０３】
圧電基板１２Ａ、１２Ｂの出力は、増幅回路１４を介してマイコン１０のＡ／Ｄコンバータ１９に接続し、これにより操作パネル３を指１１等の操作体で触れると、マイコン１０へ増幅された接触検知信号が入力される。
【０１０４】
マイコン１０は、この接触検知信号の入力を入力操作の判定条件とするが、他の構成は、第１の実施の形態と同一であるので、同一番号を付してその説明を省略する。
【０１０５】
図６に示すように、マイコン１０は、各スイッチユニットＵの発光期間ｔｏｎのそれぞれで、１１で示す割込時間に、Ａ／Ｄコンバータ１９から接触検知信号を読み込む。従って、各スイッチユニットＵの各走査周期Ｔ毎に接触検知信号の有無、すなわち操作パネル３への接触が検出される。
【０１０６】
本実施の形態では、第１の実施の形態と同じ方法で特定のスイッチユニットＵに対する入力操作を判定した前後推定操作期間（例えば、２００ｍｓｅｃ）以内に接触検知信号が入力されることを条件に、その入力操作の判定を有効とし、対応する命令を家電機器へ実行させる。
【０１０７】
この操作パネル入力装置５０では、操作者は、特定のスイッチユニットＵへ指１１等の操作体を接近させた後、操作パネル３に触れ、入力操作を行うが、この入力操作で通常要する時間から推定操作期間（例えば、２００ｍｓｅｃ）を設定するので、指１１の接近による入力操作の判定と接触検知信号の入力に時間差があっても、通常の入力操作である限り入力操作の判定は有効とされる。
【０１０８】
また、単に外来光の異常増加があっただけでは、接触検知信号が入力されないので、異常増加によって入力操作と判定しても、有効なものとは扱われない。
【０１０９】
以上の実施の形態では、光検出信号として赤外光を用い、受光素子６ａの受光面を、赤外光検出信号の赤外線のみを透過させる赤外フィルタ８で覆い、赤外光以外の外来光や内部散乱光が受光素子６ａで受光されることを防止しているが、受光量を比較して入力操作状態が判定できれば、必ずしも、特定波長の光検出信号を用いる必要はない。
【０１１０】
また、操作エリアが３０が比較的広い面積の操作エリア３０である場合には、一つの操作エリア３０に対応して設けられる光スイッチユニットＵに、同時に赤外光検出信号を発光する複数の発光手段５と、その発光タイミングで受光する複数の受光手段６とを対として有するものであってもよく、このように対となる発光手段５と受光手段６とを多数を分散して配置することによって、操作エリア３０が広範囲であっても、操作体で反射される光検出信号を、いずれかの受光手段６が確実に受光できる。
【０１１１】
また、一走査周期Ｔ、発光時受光量Ｌｏｎ（ｃ）と発光時受光量Ｌｏｎ（ｏ）の時間差、消灯時受光量Ｌｏｆｆ（ｃ）と消灯時受光量Ｌｏｆｆ（ｏ）の時間差は、各しきい値は、入力操作状態を最も効果的に判定できるように任意に定められるものであり、上述の例に限るものではない。
【０１１２】
更に、指１１で入力操作を行う例で説明したが、指以外の専用入力ペン等を操作体と入力操作を行うものであってもよい。
【０１１３】
【発明の効果】
以上説明したように、本発明によれば、外来光や内部の散乱光が一時的に若しくは長期的に変化しても、これらの変化の影響を受けずに、入力操作を判定できる。
【０１１４】
また、入力操作状態を受光手段の受光量の変化から詳細に判別することができる。
【０１１５】
これに加えて請求項２の発明によれば、入力操作のタイミングまで、入力操作を正確に判定できる。
【０１１６】
また、請求項３の発明によれば、消灯時受光量が消灯しきい値を越えて増加したときには、入力操作と無関係な外来光及び内部散乱光による光量の増加とみなすことができ、これらの増加により発光時受光量が増加し入力操作と判定しても、判定を一定期間無効とすることで、機器の誤動作を防止できる。
【０１１７】
また、請求項４の発明によれば、消灯時受光量の変化を所定の環境しきい値と比較することによって、外来光及び内部散乱光の経年変化による影響を除き一時的な増加のみを正確に判定でき、これらの一次的増加によって入力操作と判定しても、判定を一定期間無効とすることで、機器の誤動作を防止できる。
【０１１８】
また、請求項５の発明によれば、操作パネルに対する接触を条件に、入力操作の判定を有効とするので、外来光、内部散乱光の一時的な光量変化が発生し、入力操作と判定した場合であっても、入力操作に従った命令が実行されず、機器の誤動作を確実に防止できる。
【０１１９】
また、請求項６の発明によれば、入力操作解除のタイミングを含む入力操作状態を正確に判定できる。従って、通常の入力操作の際のみならず、入力操作解除の際にも、異なる制御内容を光スイッチユニットに対して入力できる。
【０１２０】
また、請求項７の発明によれば、検出期間内に複数回検出した受光量の平均値から求めるので、検出異常値が発生しても、受光量への影響が少なく、誤判定が減少する。
【図面の簡単な説明】
【図１】本発明に係る操作パネル入力装置１の斜視図である。
【図２】操作パネル入力装置１の縦断面図である。
【図３】図２の要部拡大縦断面図である。
【図４】操作パネル入力装置１の構成を示すブロック図である。
【図５】操作パネル入力装置１の各光スイッチユニットＵから発光される赤外光検出信号を示すタイミングチャートである。
【図６】発光期間ｔｏｎと消灯期間ｔｏｆｆ内に、受光量と接触検知信号を読み込むタイミングを示すタイミングチャートである。
【図７】特定のスイッチユニットＵに対して、指１１を接近させた後離間させる入力操作状態において、発光時受光量Ｌｏｎと消灯時受光量Ｌｏｆｆの変化を表したグラフである。
【図８】特定のスイッチユニットＵに対して、待機状態において、発光時受光量Ｌｏｎと消灯時受光量Ｌｏｆｆの変化を表したグラフである。
【図９】他の実施の形態に係る操作パネル入力装置５０の構成を示すブロック図である。
【図１０】従来の操作パネル入力装置１００を示す縦断面図である。
【図１１】従来の操作パネル入力装置１００の光スイッチユニットＵから発光される赤外線検出信号のタイミングチャートである。
【図１２】従来の操作パネル入力装置１００の操作パネル１０１内方を拡大して示す拡大縦断面図である。
【符号の説明】
１、５０操作パネル入力装置
３操作パネル（透明アクリル板）
５発光手段
６受光手段
１０マイコン（発光制御手段、受光制御手段、入力判定手段）
１２Ａ、１２Ｂ接触検知手段（圧電基板）
２１受光量記憶部（シフトレジスタ）
Ｕ光スイッチユニット
Ｔ走査周期
Ｌｏｎ発光時受光量
Ｌｏｎ（ｃ）新たに検出した発光時受光量
Ｌｏｎ（ｏ）一次記憶された発光時受光量
ｔｏｎ発光期間
ｔｏｆｆ消灯期間
Ｌｏｆｆ消灯時受光量
Ｌｏｆｆ（ｃ）新たに検出した消灯時受光量
Ｌｏｆｆ（ｏ）一次記憶された消灯時受光量[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an operation panel input device mainly for performing various input operations on home appliances, and more particularly to an operation panel input device capable of performing an input operation without touching the operation panel.
[0002]
[Prior art]
[0003]
Home appliances such as a water heater and a washing machine are provided with an operation panel on which operation switches for operating these devices are concentrated. The operator performs a predetermined operation control on the device by pressing any one of the operation switches with a finger.
[0004]
However, since it is a structure that is operated by directly pressing the operation switch with a finger, there is a problem in its durability because it has to use moving parts, and the surface of the operation switch becomes dirty when the finger touches it. There was a problem that the aesthetic feeling of the operation panel was impaired.
[0005]
For this reason, a non-contact type operation panel input device capable of executing a predetermined operation without directly touching the operation panel with a finger is known (for example, Patent Document 1).
[0006]
[Patent Document 1]
JP 2000-100267 (4th page, FIG. 2)
[0007]
FIG. 10 shows this conventional operation panel input device 100, and a plurality of sets of optical switch units U corresponding to the control contents to the home appliances are provided inside the operation panel 101 formed of a transparent acrylic plate. ₁ (For example, power ON of home appliances is controlled ON), U ₂ ・・ Is placed.
[0008]
Each set of optical switch unit U is 455K _HZ An infrared light emitting element 102 that emits an infrared detection signal having a natural frequency of 2 and an infrared light receiving element 103 that can receive the infrared detection signal emitted from the infrared light emitting element 102.
[0009]
As shown in FIG. 11, the infrared detection signals emitted from each optical switch unit U are mutually different from each other optical switch unit U. ₁ , U ₂ The light is repeatedly emitted from the infrared light emitting element 102 at a predetermined scanning period T so as not to overlap with the infrared detection signal emitted from.
[0010]
As shown in FIG. 10, the infrared light emitting element 102 and the infrared light receiving element 103 that form a pair in the same optical switch unit U are mounted on a printed wiring board 104 so as to be adjacent to each other. An infrared filter 105 that transmits only infrared light is disposed between the operation panels 101.
[0011]
Therefore, the infrared detection signals emitted from each pair of infrared light emitting elements 102 are output to the outside through the infrared filter 105 and the operation panel 101 above them. Only the infrared ray including the light passes through the operation panel 101 and the infrared filter 105 in the vicinity thereof and reaches the infrared light receiving element 103.
[0012]
On the output side of the infrared light receiving element 103 is 455K. _HZ There is provided a microcomputer for determining an input operation to the optical switch unit U through a band-pass filter that passes a photoelectric conversion signal of the natural frequency. Therefore, only when the infrared light receiving element 103 receives an infrared detection signal having a natural frequency, the photoelectric conversion signal is input to the microcomputer. Thereby, natural light, another remote control transmission signal, etc., and the infrared detection signal emitted from the infrared light emitting element 102 can be identified by the light receiving means 103.
[0013]
When there is no object that reflects the infrared detection signal in the vicinity of the optical switch unit U, the infrared detection signal emitted from the infrared light emitting element 102 at a predetermined scanning cycle is sent to the pair of the same optical switch unit U. Thus, the infrared light receiving element 103 does not receive light, and no photoelectric conversion signal is input to the microcomputer. In this state, the microcomputer determines that an input operation to the optical switch unit U has not been performed.
[0014]
On the other hand, below the optical switch unit U ₁ For example, when an input operation is performed by bringing a finger close to the operation panel 101 in which the infrared light is arranged, the infrared detection signal emitted from the infrared light emitting element 102 is reflected by the finger approaching above the operation panel 101, and the operation is performed again. The same optical switch unit U is transmitted through the panel 101 and the infrared filter 105. ₁ The infrared light receiving element 103 is input. The microcomputer converts the photoelectric conversion signal photoelectrically converted by the infrared light receiving element 103 into the same optical switch unit U. ₁ When the infrared light emitting element 102 inputs an infrared detection signal almost simultaneously with the timing at which the infrared detection signal is emitted, the optical switch unit U ₁ For example, it is determined that an input operation has been performed, and a control signal for turning on the power is output to the home appliance.
[0015]
At this time, another optical switch unit U ₂ In the infrared light receiving element 103, the infrared detection signal reflected by the finger may be received. ₂ Since the photoelectric conversion signal is input to the microcomputer at a timing different from the timing at which the infrared light emitting element 102 emits the infrared detection signal, the optical switch unit U ₂ It is not recognized as an input operation for.
[0016]
In general, inside the operation panel 101, as shown in FIG. 12, a liquid crystal display panel 106 for displaying the control contents and operation method of each optical switch unit U or the operation state of the home appliance, On the other hand, a diffusion sheet 107 and a light guide plate 108 are laminated. The light guide plate 108 guides light from a light source (not shown) to the entire back surface of the liquid crystal display panel 106 and acts as a backlight of the liquid crystal display panel 108. The diffusion sheet 107 is disposed outside the operation panel 101. The optical path is diffused so that the optical switch unit U and the like cannot be seen.
[0017]
[Problems to be solved by the invention]
[0018]
According to the operation panel input device 100, the finger does not directly touch the operation panel 101 to contaminate the surface thereof, and since no movable parts are used, the durability can be improved.
[0019]
However, since an infrared signal having a natural frequency is used as a photodetection signal, it is necessary to provide an infrared filter, a modulation / demodulation circuit, and a bandpass filter, which is complicated in structure and includes infrared light having the same frequency as external light. There was a risk of misrecognizing it as an input operation.
[0020]
Further, since the amount of light received by the infrared detection signal that is reflected by the finger and reaches the infrared light receiving element 103 is extremely weak compared to the amount of light emitted by the infrared detection signal emitted from the infrared light emitting element 102, the infrared detection signal In some cases, the infrared light receiving element 103 is saturated due to the influence of extraneous light other than the above or scattered light in the operation panel input device 100, making detection difficult.
[0021]
For example, when it is determined that an input operation to the optical switch unit U is performed by inputting a photoelectric conversion signal by a microcomputer, the level of the photoelectric conversion signal, that is, the infrared detection signal received by the infrared light receiving element 103 is set to a predetermined input threshold. Although the input operation is determined in comparison with the value, the influence of the fluctuation of the external light and the fluctuation of the scattered light inside cannot be ignored. Therefore, only the input of the infrared detection signal cannot be accurately determined.
[0022]
In addition, the amount of light received by the infrared light receiving element 103 is not limited to the temporary change of external light as described above, but the operation panel 101, the liquid crystal display panel 106, the diffusion sheet 107, which are interposed in the optical path of the infrared detection signal, If the light guide plate 108 changes due to aging, such as contamination or deterioration, the input operation may not be judged at all if the amplification factor of the infrared detection signal is fixed and compared with a predetermined threshold value. This is a cause of erroneous determination that it is determined that the input operation is always performed.
[0023]
Furthermore, in the conventional operation panel input device 100, the input operation itself can be determined without directly touching the operation panel 101, but the input operation state such as the timing of the input operation and the input operation release cannot be determined in more detail. .
[0024]
The present invention has been made in consideration of such conventional problems, and provides an operation panel input device that can accurately determine an input operation even when external light or internal scattered light temporarily changes. For the purpose.
[0025]
It is another object of the present invention to provide an operation panel input device that can accurately determine an input operation even when the arrival amount of an infrared detection signal changes due to secular change.
[0026]
It is another object of the present invention to provide an operation panel input device that can determine the input operation state in detail.
[0027]
[Means for Solving the Problems]
[0028]
The operation panel input device according to claim 1 is configured such that at least a part of the operation panel serving as a light transmission portion and each optical switch unit SW are disposed inside the operation panel, and outward from the light transmission portion of the operation panel. A plurality of optical switch units SW having a pair of a light emitting means for emitting a light detection signal and a light receiving means capable of receiving the light detection signal reflected outside the light transmitting portion, and light emission of each optical switch unit SW A light emission control means for causing the light detection signal to repeatedly emit at least a scanning cycle shorter than the input operation time so as not to overlap with the light detection signal emitted from the light emission means of the other optical switch unit SW; The light receiving control means for detecting the amount of light received by the paired light receiving means in the same optical switch unit U in synchronization with the scanning cycle for emitting the light detection signal, and the light receiving means detected From the received light amount storage unit that primarily stores the amount of light for each light receiving unit of each optical switch unit U, and the received light amount detected by the paired light receiving unit when the light emitting unit of the optical switch unit U emits the light detection signal, An operation panel input device including an input determination unit for determining an input operation state with respect to the optical switch unit U, wherein the received light amount storage unit is a pair of light receiving units during a light emission period in which the light emitting unit emits a light detection signal. The light receiving amount detected at the time of light emission is temporarily stored, and the input determining means is the light receiving amount at the time of light emission newly detected by the light receiving means of the optical switch unit U and the light emission temporarily stored in the light receiving amount storage unit for the light receiving means. The input operation state with respect to the optical switch unit U is determined from the hourly received light amount.
[0029]
The light detection signal that is reflected by the operating body such as a finger and reaches the light receiving means increases as the operating body approaches the optical switch unit U, and decreases when the operating body leaves, so that it synchronizes with the scanning cycle in which the light emitting means emits the light detection signal. The amount of light received during light emission received by the light receiving means increases or decreases depending on the distance from the operating body.
[0030]
Therefore, by comparing the light reception amount during light emission primarily stored in the light reception amount storage unit with the newly detected light reception amount during light emission, it is possible to detect a change in the distance from the operating body, and to change the input operation state. Can be judged.
[0031]
On the other hand, changes in the amount of light due to changes over time, such as extraneous light and internal scattered light, equally affect both the received light amount received during primary storage and the newly detected received light amount detected during light emission. Since it does not appear in the amount difference, only the input operation state can be determined.
[0032]
In addition, even if there is a temporary change in the amount of extraneous light or internal scattered light, it rarely changes in the same way as the input operation. Since it does not appear in the difference in the amount of received light during light emission, only the input operation state can be determined.
[0033]
In the operation panel input device according to the second aspect, the input determining means is a light emitting time when the received light amount newly detected by the light receiving means of the optical switch unit U is temporarily stored in the received light amount storage unit for the light receiving means. When the amount of light received exceeds a predetermined input threshold value as compared with the amount of received light, the input operation for the optical switch unit U is determined.
[0034]
When the operating body approaches the optical switch unit U, the light detection signal that is reflected by the operating body and reaches the light receiving means increases. As a result, the newly detected light-receiving amount at the time of light emission is temporarily stored in the light-receiving amount storage unit. Therefore, the input operation can be accurately determined up to the timing of the input operation by comparing it with a predetermined input threshold value.
[0035]
In the operation panel input device according to claim 3, the light emission control means sets a light extinction period during which the light detection signal is not emitted from the light emission means of all the optical switch units U within at least one scanning period, and the light reception control means. Is to cause the light receiving means of at least one of the optical switch units U to detect the light reception amount at the time of extinction during the extinguishing period, and when the light reception amount at the time of extinction detected by the light receiving means exceeds a predetermined extinction threshold value, The determination of the input operation by the input determination unit for all the optical switch units U is invalidated for a certain period.
[0036]
Since the light reception amount detected by the light receiving means does not include the light detection signal, the light quantity of the external light and the internal scattered light unrelated to the input operation appears. Therefore, when the amount of light received during extinction increases beyond the extinction threshold, it can be regarded as an increase in the amount of light due to extraneous light and internal scattered light unrelated to the input operation. Even if it is determined that the operation is an input operation, malfunction of the device can be prevented by invalidating the determination for a certain period.
[0037]
A misjudgment caused by a temporary light quantity change can be reliably prevented without using any other input operation recognition means.
[0038]
In the operation panel input device according to the fourth aspect, the light emission control means sets a light extinction period in which the light detection signal is not emitted from the light emission means of all the optical switch units U within at least one scanning cycle, and the light reception control means. Causes the light receiving means of at least one of the optical switch units U to detect the light reception amount when the light is turned off during the light extinction period, and the light reception amount storage unit displays the light reception amount detected when the light receiving means is detected during the light extinction period. The light-receiving amount that is temporarily stored together with the light-receiving amount and that is newly detected by the light-receiving unit exceeds the predetermined environmental threshold value compared to the light-receiving amount that is temporarily stored in the light-receiving amount storage unit for that light-receiving unit. The determination of the input operation by the input determination unit for all the optical switch units U is invalidated for a certain period.
[0039]
The temporary change in the amount of light received when the light is turned off does not show the influence of the light detection signal or the change in the light amount due to the aging of the external light and the internal scattered light. Therefore, when the newly detected light-receiving amount at the time of extinction is larger than the light-receiving amount at the time of extinction that is primarily stored in the light-receiving amount storage unit and exceeds a predetermined environmental threshold, temporary light of external light and internal scattered light is temporarily Even if it is determined that the received light amount at the time of light emission is an input operation due to these increases, it is possible to prevent malfunction of the device by invalidating the determination for a certain period.
[0040]
In particular, it is possible to reliably prevent misjudgment due to a temporary change in the amount of light even if another input operation recognition means is not used together and the amount of light of the external light and the internal scattered light changes due to aging.
[0041]
According to another aspect of the operation panel input device of the present invention, the contact detection means for detecting contact with the operation panel is disposed on the operation panel, and the contact detection means is within a predetermined estimated operation period before and after the input determination means determines that the input operation is performed. On the condition that the contact detection signal is input from the input, the determination of the input operation to the optical switch unit U is made valid.
[0042]
Since the determination of the input operation is enabled on the condition that the touch on the operation panel, even if the temporary light amount change of the external light and the internal scattered light similar to the input operation occurs, and the input operation is determined, The command according to the input operation is not executed, and the malfunction of the device can be surely prevented.
[0043]
The time difference between the input operation determination due to the approach of the operating body and the contact with the operation panel is within the estimated operation period estimated from the normal input operation. Therefore, if the input operation is normal, the input operation determination and contact detection Even if a time difference occurs in the output of the signal, the determination of the input operation is valid.
[0044]
In the operation panel input device according to the sixth aspect of the present invention, the input determining means is a light emitting time when the received light amount newly detected by the light receiving means of the optical switch unit U is temporarily stored in the received light amount storage unit for the light receiving means. It is characterized in that it is determined that the input operation to the optical switch unit U is canceled when it decreases beyond a predetermined cancellation threshold value as compared with the amount of received light.
[0045]
When the operating body that has approached the optical switch unit U is separated, the light detection signal that is reflected by the operating body and reaches the light receiving means decreases. Therefore, the input operation state including the input operation release timing can be accurately determined by comparing with the predetermined release threshold value.
[0046]
Accordingly, different control contents can be input to the optical switch unit not only during a normal input operation but also when the input operation is canceled.
[0047]
The operation panel input device according to claim 7, wherein the light receiving means detects the amount of received light a plurality of times within a period in which the light emitting means detects the amount of received light in synchronization with the scanning cycle in which the light detection signal is emitted, and the average The value is the amount of received light detected by the light receiving means.
[0048]
The light receiving means obtains the amount of light received once in each scanning period from the average value of the amount of light detected multiple times during the detection period, so even if a detection abnormal value occurs, there is little effect on the amount of received light, Misjudgments are reduced.
[0049]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of an operation panel input device 1 according to the present invention will be described below with reference to FIGS.
[0050]
FIG. 1 is a perspective view of an operation panel input device 1, which is provided in a water heater (not shown) attached to a unit bath that is a home appliance. The operation panel input device according to the present invention is particularly suitable for washing machines, bath water heaters, and the like that are required to be waterproof, but is attached to these as input devices for controlling other electrical devices such as acoustic devices and air conditioning devices. It may be prepared.
[0051]
The operation panel input device 1 includes a rectangular transparent acrylic plate 3, a liquid crystal display panel 4, a backlight panel 7, a reflection plate 9, and a printed wiring board 13 that are to be operated from the outside (upper side in FIG. 2). These are disposed in a laminated state, and are opposed to each other in a stacked state, and are housed in a case 2 made of synthetic resin.
[0052]
The case 2 includes a bowl-shaped base 2a that opens outward, and a pressing cover 2b that fits around the bowl and has a fixing frame 22 protruding above the bowl, and is attached to the flanges of both of them. Are integrated.
[0053]
Adhesives, adhesives, and the like are applied between the case 2 and the transparent acrylic plate 3 so that water droplets, dust, and the like do not enter the operation panel input device 1.
[0054]
By providing a step corresponding to the thickness of the fixed frame 22 around the transparent acrylic plate 3, the surface of the transparent acrylic plate 3 and the surrounding case 2 are aligned on the same plane.
[0055]
The liquid crystal display panel 4 displays, through the transparent acrylic plate 3, control details for performing an input operation on the water heater and a predetermined display relating to the operation of the water heater. In the water heater shown in FIG. Display 30a, 30b, 30c... Indicating input operations such as input, start of hot water supply operation, selection of chasing, etc. are displayed together with operation areas 30A, 30B, 30C. Moreover, in this display, the hot water supply amount 31 into the bathtub and the hot water supply temperature 32 are displayed.
[0056]
The display by the liquid crystal display panel 4 is displayed under the control of a liquid crystal driver (not shown). The position and number of the display 30 indicating the operation area and the input operation, and the other displays depend on the operating state of the water heater. Variable.
[0057]
The backlight panel 7 illuminates the display of the liquid crystal display panel 4 from the inside. The backlight panel 7 guides the backlight light from the backlight light source 40 (see FIG. 3) disposed on the end surface thereof to the inside thereof. Yes. The backlight panel 7 is formed of a transparent acrylic plate with a diffusion sheet 7A attached to the surface (the surface facing the liquid crystal display panel 4), and on the back side, the reflecting plate 9 having a white facing surface. Therefore, the backlight light emitted from the backlight light source is guided to the outside while being scattered inside the backlight panel 7. Thereby, from the outside of the transparent acrylic plate 3, a specific backlight light source is not confirmed, and it seems as if the entire background of the display by the liquid crystal display panel 4 is illuminated by the backlight light.
[0058]
In the present embodiment, the backlight panel 7 and the backlight light source 40 are divided by the slit plate 33 for each operation area 30, and the back surface of the operation area 30 is illuminated with different light sources.
[0059]
As described above, the reflecting plate 9 is coated with white paint on the surface so that the surface facing the backlight panel 7 is white, and the backlight is reflected in the backlight panel 7 so as not to escape downward. ing. Since it is white, if the backlight light is colored in a predetermined color, the background of the liquid crystal display panel 4 is viewed as if it has changed to that color. In the reflecting plate 9, an output side small hole 34 is formed above (on the front surface side) in FIG. 3 of the light emitting element 5a described later, and an input side small hole 35 is formed above the light receiving element 6a. These small holes 34 and 35 are small holes having an inner diameter of about 1 to 1.5 mm, for example, and the light path is scattered by the diffusion sheet 7A on the surface side of the backlight panel 7, so that the transparent acrylic plate 3 It is not visible from the outside.
[0060]
The printed circuit board 13 attached to the back side of the reflector 9 has an optical switch unit U corresponding to each of the operation areas 30A, 30B, 30C,. ₁ , U ₂ , U ₃ ,... Are arranged (see FIG. 4). Each optical switch unit U includes a light emitting means 5 having an infrared light emitting element 5a, and a light receiving means 6 having an infrared light receiving element 6a capable of receiving an infrared light detection signal emitted from the infrared light emitting element 5a. Configured as a pair. In the present embodiment, an infrared light emitting diode is used as the infrared light emitting element 5a, and a pin photodiode is used as the infrared light receiving element.
[0061]
As shown in FIG. 3, the infrared light emitting element 5 a and the infrared light receiving element 6 a of the same optical switch unit U are provided in the output hole 36 and the input hole 37 formed in the printed wiring board 13, respectively, It is mounted on the back side of the printed wiring board 13 with its light receiving surface facing. An infrared filter 8 that transmits only infrared rays of the infrared light detection signal is formed on the light receiving surface of the infrared light receiving element 6a.
[0062]
The output hole 36 and the input hole 37 have inner diameters slightly larger than the inner diameters of the output side small hole 34 and the input side small hole 35 of the reflector 9 stacked on the surface side, and the output side small hole 34 and the input side small hole, respectively. 35, the infrared light detection signal emitted from the infrared light emitting element 5a of each optical switch unit U passes through the output hole 36 and the output side small hole 34, Light radiated outward from the transparent acrylic plate 3 and received from the outside of the transparent acrylic plate 3 passes through the input side small hole 35 and the input hole 37, and further passes through the infrared filter 8, whereby red Infrared light including an external light detection signal is input to the infrared light receiving element 6a.
[0063]
FIG. 4 is a block diagram showing each circuit configuration of the operation panel input device 1 according to the present embodiment. Hereinafter, the operation panel input device 1 and its operation will be described along the block diagram.
[0064]
Each optical switch unit U ₁ , U ₂ , U ₃ Each of the infrared light emitting elements 5a is connected to an LED multiplexer 16 that is connected and controlled by the microcomputer 10, and emits an infrared light detection signal at a light emission timing controlled by the microcomputer 10 acting as a light emission control means. That is, as shown in FIG. ₁ , U ₂ , U ₃ The infrared light emitting element 5a emits an infrared light detection signal at a timing not to overlap with the other infrared light emitting elements 5a, with a light emitting period ton of 0.5 msec before and after a light extinction period toff of 0.5 msec. No infrared light detection signal is emitted from any of the infrared light emitting elements 5a during the front and rear extinction periods toff.
[0065]
The light emission control is repeated after the light emission control for all the infrared light emitting elements 5a, and the one scanning period T is set to a time shorter than the time required for the input operation. The time required for the input operation by the operator is estimated to be 50 msec to 200 msec empirically, although there are individual differences, and here is 15 msec, which is shorter than 50 msec.
[0066]
On the other hand, each optical switch unit U ₁ , U ₂ , U ₃ The infrared light receiving element 6a that is paired with each of the infrared light emitting elements 5a is connected to a Pd multiplexer 17 that is connected and controlled by the microcomputer 10, and the light receiving timing described later controlled by the microcomputer 10 that also functions as a light receiving control means. Receive light at.
[0067]
The output of the Pd multiplexer 17 is connected to the A / D converter 19 of the microcomputer 10 via the amplifier circuit 18. Therefore, the amount of received light detected by the infrared light receiving element 6a at the light receiving timing controlled by the microcomputer 10 is amplified by the amplifier circuit 18, A / D converted by the A / D converter 19, and then input to the microcomputer 10. Is done.
[0068]
This light reception timing is synchronized with a scanning cycle T in which light emission control of the light emitting element 5a is performed, and the light reception timing is set for each pair of infrared light receiving elements 6a. Here, each switch unit U shown in FIG. ₁ , U ₂ , U ₃ The received light amount is detected for each light emission period ton during which the infrared light emitting element 5a emits light.
[0069]
FIG. 6 shows the details of detecting the amount of received light in each light emission period ton, and the interrupt process is performed four times in each light emission period ton (interruption time from 12 to 15 in the figure). The amount of received light at that time is read into the / D converter 19.
[0070]
In the microcomputer 10, the four received light amounts read from the A / D converter 19 during the light emission period ton are averaged to obtain a newly detected received light amount Lon (c). Thus, by averaging the received light amounts detected a plurality of times, even if an error occurs in one detection, the influence on the received light amount output to the microcomputer 10 is reduced. The light reception amount Lon (c) at the time of light emission is compared with a light reception amount Lon (o) at the time of light emission which will be described later in the microcomputer 10, and the maximum amount of the shift register 21 having four stages connected to the microcomputer 10 is provided for each switch unit U. Stored in the lower row.
[0071]
The same processing is performed for each switch unit U. ₁ , U ₂ , U ₃ Is repeated at each scanning cycle T, and the newly detected light reception amount Lon (c) at the time of light emission is stored in the lowermost stage of the shift register 21, and the light reception amount stored in each stage is sequentially shifted to the upper stage. It is. As a result, the light reception amount Lon (o) at the time of light emission stored in the uppermost stage of the shift register 21 for a specific switch unit U is 4T time before the new light reception amount detection for the same switch unit U, that is, 60 msec. It represents the amount of received light detected previously.
[0072]
FIG. 7 shows the received light amount Lon at the time of light emission input to the microcomputer 10 for each scanning period T with respect to a specific switch unit U in the input operation state in which the finger 11 that is the operating body is approached and then separated. This is a graph showing changes in the received light amount Lon during light emission.
[0073]
From T1 to T2 in the figure, the state is a standby state before the input operation, and the finger 11 is separated from the switch unit U. Therefore, the infrared light receiving element 6a is an infrared light detection signal that is scattered internally with extraneous light. And the received light amount Lon at the time of light emission is 1V.
[0074]
When the finger 11 is approached by the input operation from this standby state, the infrared light detection signal reflected by the finger 11 is gradually increased to increase the light receiving amount Lon at the time of light emission, and T7 that is closest to the switch unit U is reached. The peak of about 1.5V is reached.
[0075]
Thereafter, when the finger 11 is moved away, the reflected infrared light detection signal gradually decreases and the received light amount Lon at the time of light emission also decreases, and the standby state returns to 1V at about 12 o'clock.
[0076]
In the present embodiment, the input operation state is detected from the light reception amount Lon at the time of light emission that changes in accordance with the contact and separation of the finger 11, and the light reception amount of light at the time of light emission Lon (c) newly detected by the microcomputer 10 is detected. Is compared with the received light amount Lon (o) at the time of light emission stored in the uppermost stage of the shift register 21, and is determined to be an input operation when it exceeds a predetermined input threshold, here 0.3v To do.
[0077]
For example, in FIG. 7, the received light amount Lon (c) during light emission at T5 is 1.25V, and the received light amount Lon (o) during light emission before 4T hours is 1V, so the difference does not exceed the input threshold value. At T6, the received light amount Lon (c) at the time of light emission is 1.4V, and the received light amount Lon (o) at the time of light emission at T2 4T before is 1V. It is determined.
[0078]
Further, the microcomputer 10 compares the newly received light reception amount Lon (c) detected with the light emission with the light emission reception amount Lon (o) stored in the uppermost stage of the shift register 21 to obtain a predetermined release threshold value. Here, it is determined that the input operation is canceled when the voltage decreases by 0.3 V or more.
[0079]
For example, in FIG. 7, the light reception amount Lon (c) during light emission at T10 is 1.3V, and the light reception amount Lon (o) during light emission 4T hours ago is 1.4V, so the release threshold value does not exceed, At T11, the received light amount Lon (c) during light emission is 1.1V, and the received light amount Lon (o) during light emission at T7, 4T hours ago, is 1.5V. It is determined that the operation is canceled.
[0080]
The microcomputer 10 determines whether the input operation and the input operation are canceled by each switch unit U. ₁ , U ₂ , U ₃ Each time, the newly detected light reception amount Lon (c) during light emission is compared with the light reception amount Lon (o) read out from the shift register 21.
[0081]
When the microcomputer 10 determines that the input operation is to the specific switch unit U, the instruction associated with the switch unit U is executed to the water heater. For example, the switch unit U arranged below the operation area 30A displaying the display 30a indicating the input operation of the main power input. ₁ If the input operation is determined, the water heater is turned on.
[0082]
In this embodiment, since the input operation state for each switch unit U including the timing of canceling the input operation can be determined, another command can be output for determining whether to cancel the input operation, or the input operation and the input operation can be performed. The determination result can be used for various purposes, such as finalizing the determination of the input operation at the time interval determined to cancel the release.
[0083]
In the first embodiment, even when the level of the received light amount Lon at the time of light emission received by the infrared light receiving element 6a is gradually changed due to the influence of secular change and external light gradually changing, the input is performed. Both the received light amount Lon (c) and the received light amount Lon (o) at the time of light emission to be compared in the determination of the release of the operation or the input operation are affected by the difference, and therefore, there is a change between them. Can accurately determine the input operation state.
[0084]
However, in the first embodiment, extraneous light and internal scattering reaching the infrared light receiving element 6a due to various causes such as an indoor curtain being opened, illumination being turned on, and insects approaching. If the light changes temporarily, and these changes rarely increase in the same manner as the change in the amount of light caused by the input operation, there is a risk of erroneous determination as an input operation.
[0085]
FIG. 8 is a graph showing a change in which the received light amount Lon at the time of light emission increases as in the case of the input operation even when the input operation is not performed on the specific switch unit U due to the above reasons. In FIG. 8, the amount of received light Lon (c) at the time of light emission is changed from 1 V 4 hours before to 1.4 V at T6, even though the finger 11 is not approached due to a sudden increase in external light and internal scattered light. And the input threshold value is exceeded, and the input operation is erroneously determined.
[0086]
The second embodiment described below detects such a state of erroneous determination, invalidates the input operation for a certain period, and prevents malfunction of a controlled device such as a home appliance. .
[0087]
In the second embodiment, the microcomputer 10 acting as the light reception control means is the first embodiment, and each switch unit U shown in FIG. ₁ , U ₂ , U ₃ In addition to every period ton in which the infrared light emitting element 5a emits light, the amount of received light is also detected in the extinguishing period toff immediately before that.
[0088]
The details of detecting the amount of received light during the light-off period toff are the same as the detection during the light-emitting period ton. As shown in FIG. 6, the interrupt process is performed four times for each light-off period toff ( (Intermediate 4 to 7 interruption time), the A / D converter 19 reads the received light amount at that time.
[0089]
In the microcomputer 10, the four received light amounts read from the A / D converter 19 during the extinguishing period toff are averaged to obtain a newly detected extinguishing received light amount Loff (c). In detecting the light reception amount Loff (c) when the light is turned off, the light reception amounts detected a plurality of times are similarly averaged to reduce the influence on the detection value due to one detection error. Similarly to the light reception amount Lon (c) during light emission, the light reception amount Loff (c) during light extinction is stored at the bottom of the shift register 21 for each switch unit U, and the light reception amount Loff (c) during light extinction newly detected. Each time is stored in the lowermost stage of the shift register 21, it is sequentially moved to the upper stage.
[0090]
In the microcomputer 10, for each switch unit U, the newly detected light reception amount Loff (c) when extinguished and the light reception amount Loff (o) when extinguishing stored in the uppermost stage of the shift register 21, that is, 4T time (60 msec) ) Compare the amount of light received Loff (o) at the time of extinction detected before and detect an abnormal increase in external light and internal scattered light.
[0091]
That is, the newly detected light reception amount Loff (c) at the time of extinction exceeds a predetermined environmental threshold, here 0.3 v, compared with the light reception amount Loff (o) at the time of extinction detected 4T before. When the number of the switch units U increases, it is determined that the extraneous light and the internal scattered light are abnormally increased, and the determination of the input operation for all the switch units U for a predetermined period (for example, several seconds) is invalidated. Therefore, even if the specific switch unit U determines that the input operation is based on the increase in the received light amount Lon at the time of light emission, the determination is invalidated, and an unintended command is not executed by a home appliance or the like.
[0092]
This will be described with reference to FIG. 8 in which the change in the light reception amount Loff at the time of extinction is connected and displayed by a broken line. The light reception amount Lon (c) at the time of T1 receives the internal scattered light including the external light and the infrared detection signal. Whereas it is 1V, the light reception amount Loff (c) at the time of extinguishing at T1 (precisely 0.5 msec before) is 0.8V, which is slightly lower because it does not include the internal scattered light due to the infrared detection signal. ing.
[0093]
When extraneous light or internal scattered light (hereinafter simply described as extraneous light) increases to the same extent as the input operation due to the curtain being pulled, the received light amount Loff (c) when extinguished and the received light amount Loff (c) when extinguished ) Also increases. As a result, at T6, the received light amount Lon (c) during light emission exceeds the input threshold value 0.3V compared to the received light amount Lon (o) during light emission 4T hours ago, and it is determined as an input operation. , The light reception amount Loff (c) at the time of extinction at T6 also increases beyond the environmental threshold value 0.3V from the light reception amount Loff (o) at the time of extinction of 4T hours due to an increase in external light or the like. This determination is invalid.
[0094]
On the other hand, in FIG. 7 showing the state of the input operation, the external light is blocked by the finger 11 that performs the input operation if there is no abnormal increase in the external light so that the change in the light reception amount Loff at the time of extinction is indicated by a broken line. Therefore, the light reception amount Loff at the time of extinguishing rather decreases, and the increase does not exceed the environmental threshold value, so that the determination of the input operation is kept valid.
[0095]
As shown in the figure, when the finger 11 is separated, the light reception amount Loff at the time of extinction temporarily increases, but the increase does not exceed the environmental threshold, and further, the light reception amount at the time of light emission. While Lon is decreasing, a method of not comparing the change in the light reception amount Loff at the time of extinction with the environmental threshold value may be adopted.
[0096]
Note that the input threshold value and the environmental threshold value are not necessarily the same value, and even if there is an abnormal increase in external light, the threshold value is not exceeded at the same time. Even when the environmental threshold value is exceeded within, for example, 2T time (30 msec) before and after exceeding the value, it is desirable to invalidate the determination of the input operation.
[0097]
Further, the abnormal increase in external light equally affects all the switch units U, and therefore it is not always necessary to detect the light reception amount Loff at the time of extinction for all the switch units U.
[0098]
In the second embodiment, the light reception amount Loff (c) when extinguished is primarily stored in the shift register 21 for each switch unit U, but the light reception amount Loff when extinguished is detected every scanning cycle T. (C) is compared with a fixed value extinction threshold value, and when the extinction threshold value is exceeded, it is determined that the extraneous light has increased abnormally, and the input operation determination of all switch units U for a predetermined period is invalidated It is good. For example, even if the extinction threshold value is determined by an absolute value such as 1.2 V that is predicted to be anomalous external light, it is, for example, +0.3 V with respect to the received light amount Loff during extinction in a standby state where no input operation is performed It may be determined as follows.
[0099]
FIG. 9 is a block diagram showing an operation panel input device 50 according to a third embodiment in which a part of the first embodiment is improved and an input operation is accurately determined even if there is an abnormal increase in external light. As is apparent from comparison with FIG. 4, the piezoelectric substrates 12 </ b> A and 12 </ b> B are fixed along the orthogonal X and Y peripheral edges of the transparent acrylic plate 3 serving as an operation panel.
[0100]
In the present embodiment, the piezoelectric effect by the piezoelectric substrates 12A and 12B is used (a voltage signal generated from mechanical strain is used) as contact detection means for the operation panel 3. When the finger 11 is touched, the distortion generated in the transparent acrylic plate 3 is transmitted to the piezoelectric substrates 12A and 12B fixed to the periphery, and a voltage signal is generated by bending the piezoelectric substrates 12A and 12B. The signal is used as a contact detection signal.
[0101]
Since the piezoelectric substrates 12A and 12B are attached to the periphery of the transparent acrylic plate 3, the display area of the liquid crystal display panel 4 is not narrowed and can be attached to the periphery that cannot be seen from the outside. However, the attachment positions of the piezoelectric substrates 12A and 12B may be fixed to any position as long as contact with the transparent acrylic plate 3 can be detected.
[0102]
Further, in the present embodiment in which the piezoelectric substrates 12A and 12B are fixed, it is necessary to transmit the strain due to contact with the transparent acrylic plate 3 to the piezoelectric substrates 12A and 12B, so that the deformation of the transparent acrylic plate 3 is not restrained. In addition, a buffer plate made of synthetic rubber, an adhesive, or the like needs to be interposed between the case 2 and the case 2.
[0103]
The outputs of the piezoelectric substrates 12A and 12B are connected to the A / D converter 19 of the microcomputer 10 via the amplifier circuit 14, and when the operation panel 3 is touched by an operating body such as the finger 11, the amplified contact to the microcomputer 10 is achieved. A detection signal is input.
[0104]
The microcomputer 10 uses the input of the contact detection signal as a determination condition for the input operation, but the other components are the same as those in the first embodiment, so the same reference numerals are given and the description thereof is omitted.
[0105]
As shown in FIG. 6, the microcomputer 10 reads the contact detection signal from the A / D converter 19 during the interruption time indicated by 11 in each light emission period ton of each switch unit U. Accordingly, the presence / absence of a contact detection signal, that is, contact with the operation panel 3 is detected for each scanning period T of each switch unit U.
[0106]
In the present embodiment, on the condition that the contact detection signal is input within an estimated operation period (for example, 200 msec) before and after the input operation for the specific switch unit U is determined by the same method as the first embodiment. The determination of the input operation is validated, and the corresponding command is executed by the home appliance.
[0107]
In this operation panel input device 50, the operator touches the operation panel 3 after making an operating body such as the finger 11 approach the specific switch unit U, and performs an input operation. Since the estimated operation period (for example, 200 msec) is set, even if there is a time difference between the determination of the input operation due to the approach of the finger 11 and the input of the contact detection signal, the determination of the input operation is valid as long as it is a normal input operation. The
[0108]
In addition, a contact detection signal is not input simply by an extraordinary increase in extraneous light. Therefore, even if the input operation is determined to be due to an abnormal increase, it is not treated as effective.
[0109]
In the above embodiment, infrared light is used as the light detection signal, the light receiving surface of the light receiving element 6a is covered with the infrared filter 8 that transmits only the infrared light of the infrared light detection signal, and external light other than infrared light. Although the internal scattered light is prevented from being received by the light receiving element 6a, it is not always necessary to use a light detection signal having a specific wavelength as long as the input operation state can be determined by comparing the amount of received light.
[0110]
When the operation area 30 is a relatively large operation area 30, a plurality of light emission units that simultaneously emit infrared light detection signals to the optical switch unit U provided corresponding to one operation area 30. There may be a pair of means 5 and a plurality of light receiving means 6 that receive light at the light emission timing. In this way, a large number of pairs of light emitting means 5 and light receiving means 6 are arranged in a distributed manner. Thus, even if the operation area 30 is wide, any one of the light receiving means 6 can reliably receive the light detection signal reflected by the operation body.
[0111]
In addition, one scanning cycle T, the time difference between the received light amount Lon (c) during light emission and the received light amount Lon (o) during light emission, and the time difference between the received light amount Loff (c) when turned off and the received light amount Loff (o) when turned off The threshold value is arbitrarily determined so that the input operation state can be determined most effectively, and is not limited to the above example.
[0112]
Furthermore, although the example in which the input operation is performed with the finger 11 has been described, a dedicated input pen or the like other than the finger may be used for the input operation with the operating body.
[0113]
【The invention's effect】
As described above, according to the present invention, it is possible to determine an input operation without being influenced by these changes even if external light or internal scattered light changes temporarily or for a long time.
[0114]
Further, the input operation state can be determined in detail from the change in the amount of light received by the light receiving means.
[0115]
In addition, according to the invention of claim 2, it is possible to accurately determine the input operation until the timing of the input operation.
[0116]
According to the invention of claim 3, when the light reception amount at the time of extinction increases beyond the extinction threshold value, it can be regarded as an increase in the amount of light due to external light and internal scattered light unrelated to the input operation. Even if the amount of light received during light emission increases due to the increase and it is determined that the operation is an input operation, it is possible to prevent malfunction of the device by invalidating the determination for a certain period.
[0117]
According to the invention of claim 4, by comparing the change in the amount of light received at the time of extinction with a predetermined environmental threshold value, only a temporary increase can be accurately excluded except for the influence of aging of external light and internal scattered light. Even if it is determined that the input operation is based on the primary increase, it is possible to prevent malfunction of the device by invalidating the determination for a certain period.
[0118]
In addition, according to the invention of claim 5, since the determination of the input operation is made valid on the condition that the operation panel is touched, a temporary light quantity change of the external light and the internal scattered light occurs, and the input operation is determined. Even in this case, an instruction according to the input operation is not executed, and malfunction of the device can be reliably prevented.
[0119]
According to the invention of claim 6, it is possible to accurately determine the input operation state including the input operation release timing. Accordingly, different control contents can be input to the optical switch unit not only during a normal input operation but also when the input operation is canceled.
[0120]
According to the seventh aspect of the present invention, since it is obtained from the average value of the received light amount detected a plurality of times within the detection period, even if a detection abnormal value occurs, the influence on the received light amount is small and erroneous determination is reduced. .
[Brief description of the drawings]
FIG. 1 is a perspective view of an operation panel input device 1 according to the present invention.
2 is a longitudinal sectional view of an operation panel input device 1. FIG.
3 is an enlarged vertical cross-sectional view of a main part of FIG. 2;
4 is a block diagram showing a configuration of an operation panel input device 1. FIG.
FIG. 5 is a timing chart showing an infrared light detection signal emitted from each optical switch unit U of the operation panel input device 1;
FIG. 6 is a timing chart showing the timing of reading a received light amount and a contact detection signal within a light emission period ton and a light extinction period toff.
7 is a graph showing changes in the received light amount Lon during light emission and the received light amount Loff during light extinction in an input operation state in which the finger 11 is moved closer to and away from a specific switch unit U. FIG.
FIG. 8 is a graph showing changes in a light reception amount Lon during light emission and a light reception amount Loff during light extinction in a standby state with respect to a specific switch unit U.
FIG. 9 is a block diagram showing a configuration of an operation panel input device 50 according to another embodiment.
10 is a longitudinal sectional view showing a conventional operation panel input device 100. FIG.
FIG. 11 is a timing chart of infrared detection signals emitted from the optical switch unit U of the conventional operation panel input device 100.
12 is an enlarged longitudinal sectional view showing the inside of an operation panel 101 of a conventional operation panel input device 100 in an enlarged manner. FIG.
[Explanation of symbols]
1, 50 Operation panel input device
3 Operation panel (transparent acrylic plate)
5 Light emitting means
6 Light receiving means
10 Microcomputer (light emission control means, light reception control means, input determination means)
12A, 12B Contact detection means (piezoelectric substrate)
21 Received light amount storage (shift register)
U Optical switch unit
T Scan cycle
Amount of light received during Lon emission
Lon (c) newly detected amount of light received during light emission
Lon (o) The amount of light received during primary storage
ton emission period
toff off period
Loff Light level when light is off
Loff (c) Light detection amount newly detected when extinguished
Loff (o) Primary stored amount of light received at turn-off

Claims

An operation panel (3) having at least a part as a light transmission part;
Each optical switch unit (U) is disposed inside the operation panel (3), and a light emitting means (5) for emitting a light detection signal outward from the light transmitting portion of the operation panel (3), and a light transmitting portion A plurality of optical switch units (U) having a pair of light receiving means (6) capable of receiving a light detection signal reflected from the outside,
Scanning of the light emitting means (5) of each optical switch unit (U) is shorter than at least the input operation time so as not to overlap with the light detection signal emitted from the light emitting means (5) of the other optical switch unit (U). A light emission control means (10) for repeatedly emitting light detection signals at a period (T);
In synchronization with the scanning period (T) in which the light emitting means (5) emits the light detection signal, the light receiving control means (6) detects the amount of light received by the paired light receiving means (6) in the same optical switch unit (U). 10) and
A received light amount storage unit (21) for primarily storing the received light amount detected by the light receiving means (6) for each light receiving means (6) of each optical switch unit (U);
The input operation state with respect to the optical switch unit (U) is determined from the amount of received light detected by the pair of light receiving means (6) when the light emitting means (5) of the optical switch unit (U) emits a light detection signal. An operation panel input device comprising an input determination means (10),
The received light amount storage unit (21) temporarily stores the received light amount (Lon) during light emission detected by the pair of light receiving means (6) during the light emission period (ton) during which the light emitting means (5) emits the light detection signal. ,
The input determining means (10) includes a light receiving amount (Lon (c)) during light emission newly detected by the light receiving means (6) of the optical switch unit (U), and a received light quantity storage unit (21) for the light receiving means (6). The input operation state for the optical switch unit (U) is determined from the light-receiving amount during light emission (Lon (o)) primarily stored in (1).

The input determination means (10) is a light reception amount storage unit (21) for the light reception means (Lon (c)) newly detected by the light reception means (6) of the optical switch unit (U). ) Is determined to be an input operation to the optical switch unit (U) when it exceeds a predetermined input threshold value compared with the light-receiving amount at the time of light emission (Lon (o)) stored in (1). The operation panel input device according to claim 1, wherein:

The light emission control means (10) sets a light extinction period (toff) during which no light detection signal is emitted from the light emission means (5) of all the optical switch units (U) within at least one scanning cycle (T) and receives light. The control means (10) causes the light receiving means (6) of at least one of the optical switch units (U) to detect the light reception amount (Loff) at the time of extinction during the extinction period (toff),
Determination of the input operation by the input determination means (10) for all optical switch units (U) when the light reception amount (Loff) detected by the light receiving means (6) exceeds a predetermined extinction threshold value The operation panel input device according to claim 2, wherein the operation panel is invalidated for a certain period.

The light emission control means (10) sets a light extinction period (toff) during which no light detection signal is emitted from the light emission means (5) of all the optical switch units (U) within at least one scanning cycle (T) and receives light. The control means (10) causes the light receiving means (6) of at least one of the optical switch units (U) to detect the light reception amount (Loff) at the time of extinction during the extinction period (toff),
The light reception amount storage unit (21) primarily stores the light reception amount (Loff) during light extinction detected by the light reception means (6) during the light extinction period (toff) together with the light reception amount during light emission (Lon), and the light reception means (6). Is compared with the light reception amount (Loff (o)) at the time of light extinction which is newly detected by the light reception amount storage section (21) for the light receiving means (6). The input operation determination by the input determination means (10) for all optical switch units (U) is invalidated for a certain period when a predetermined environmental threshold is exceeded. Operation panel input device.

Contact detection means (12A, 12B) for detecting contact with the operation panel (3) is disposed on the operation panel (3).
On the condition that a contact detection signal is input from the contact detection means (12A, 12B) within a predetermined estimated operation period before and after the input determination means (10) determines the input operation, the optical switch unit (U) The operation panel input device according to claim 2, wherein the input operation determination is validated.

The input determination means (10) is a light reception amount storage unit (21) for the light reception means (Lon (c)) newly detected by the light reception means (6) of the optical switch unit (U). ) Is determined to be the cancellation of the input operation to the optical switch unit (U) when the light-receiving amount during light emission (Lon (o)) that is temporarily stored in (1) is decreased beyond a predetermined release threshold. The operation panel input device according to claim 1, wherein:

The light receiving means (6) detects the received light quantity a plurality of times within the period in which the light emitting means (5) detects the received light quantity in synchronization with the scanning period (T) in which the light detection signal is emitted, and receives the average value. 7. The operation panel input device according to claim 1, wherein the received light amount is detected by the means (6).