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JP3757666B2 - Pressure sensor - Google Patents

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Publication number
JP3757666B2
JP3757666B2 JP06839199A JP6839199A JP3757666B2 JP 3757666 B2 JP3757666 B2 JP 3757666B2 JP 06839199 A JP06839199 A JP 06839199A JP 6839199 A JP6839199 A JP 6839199A JP 3757666 B2 JP3757666 B2 JP 3757666B2
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key
pressed
pressure
flexible member
pair
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JP2000267666A (en
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和宏 若生
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Casio Computer Co Ltd
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Casio Computer Co Ltd
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Description

【０００１】
【発明の属する技術分野】
この発明は、電子ピアノなどの電子鍵盤楽器に用いられる感圧センサに関する。
【０００２】
【従来の技術】
従来、電子ピアノなどの電子鍵盤楽器においては、通常の押鍵後、更に鍵を押し込む力に応じて、音高や音色、音量などを変化させ、発音中の音に各種の効果を付与し、音の表現力を高めるアフタータッチ機能を有するものがある。
図３７〜図４４はその一例を示した図である。この電子鍵盤楽器は、図３７および図３８に示すように、楽器ケース内に組み込まれる鍵盤シャーシ１と、この鍵盤シャーシ１上に上下方向に回動可能に取り付けられた合成樹脂製の複数の白鍵２および複数の黒鍵３と、これら複数の鍵２、３にそれぞれ対応して配置され、押鍵時に各鍵２、３のスイッチ押圧部４により押圧されるゴムスイッチ５と、押鍵後に更に各鍵２、３が押し込まれた際に、各鍵２、３のセンサ押圧部６により押圧されて各鍵２、３の押鍵力を検出するアフタータッチ用の感圧センサ７とを備えている。
【０００３】
複数の鍵２、３のうち、白鍵２は、その後部（図３７では右側部）が鍵盤シャーシ１の後端部上に設けられた鍵支持部８に各鍵共通の支持軸９により上下方向に回動自在に取り付けられている。また、白鍵２は、鍵支持部８の前側近傍（図３７では左側近傍）における白鍵２と鍵盤シャーシ１との間に配置されたコイルばね１０により上方に付勢されている。この状態では、白鍵２の前側部（図３７では左側部）に設けられたＬ字状のストッパ片１１が鍵盤シャーシ１のバカ孔１ａを通して鍵盤シャーシ１の下面に設けられたフェルトなどの上限ストッパ１２に当接し、これにより白鍵２が所定の上限位置（初期位置）に位置規制されている。さらに、白鍵２は、上限ストッパ１２の近傍に位置する鍵盤シャーシ１上に設けられた鍵ガイド部１３により横振れが阻止されている。なお、黒鍵３は、図３９（ｂ）に示すように、白鍵２よりも全体の長さが短く、かつ白鍵２よりも高さが高く形成されており、これ以外は白鍵２と同じ構成で、鍵盤シャーシ１上に設けられている。この場合、白鍵２と黒鍵３とは、その各長さが異なるため、各先端部（図３７では左端部）におけるモーメントが白鍵２と黒鍵３とで異なっている。
【０００４】
また、ゴムスイッチ５は、図３７に示すように、各鍵２、３にそれぞれ対応する弾性変形可能な２組の膨出ゴム部５ａを備え、これら膨出ゴム部５ａが鍵盤シャーシ１の中間部の下面に設けられた回路基板１４上に配置され、この状態で各膨出ゴム部５ａが鍵盤シャーシ１の開口部１ｂを通して上方に突出している。すなわち、このゴムスイッチ５は、各膨出ゴム部５ａ内にそれぞれ可動接点が設けられ、これら可動接点に対応する回路基板１４上にそれぞれ固定接点が離間対向して設けられ、各膨出ゴム部５ａが各鍵２、３の内面に形成された２つのスイッチ押圧部４によりそれぞれ押圧されると、各膨出ゴム部５ａが弾性変形して各可動接点が各固定接点に時間差をもって接触し、これにより押鍵された鍵２、３に対応するスイッチ信号を出力するように構成されている。
【０００５】
アフタータッチ用の感圧センサ７は、押鍵された鍵２、３の各スイッチ押圧部４によりゴムスイッチ５が押圧された後、更に鍵２、３が押し込まれたときに、各鍵２、３に設けられた立て板状のセンサ押圧部６により押圧されることにより、各鍵２、３の押し込み力（感圧センサ７を押圧する力）を検出するものであり、各上限ストッパ片１１の後側近傍（同図では右側近傍）に位置する鍵盤シャーシ１上、つまり鍵支持部８の支持軸９から鍵２、３の前側（同図では左側）に向けて所定距離Ｓ０だけ離れた位置に各鍵２、３の配列方向に沿って設けられている。この感圧センサ７は、図４０（ａ）に示すように、基板１５上に電極部１６が設けられ、この電極部１６の両側に位置する基板１５上にスペーサ１７が設けられ、このスペーサ１７上に可撓性を有するセンサシート（可撓性部材）１８が基板１５と離間対向して配置され、このセンサシート１８上にフェルト（緩衝部材）１９が配置された構成で、全体が帯状に形成されている。この場合、電極部１６は、図４０（ｂ）に示すように、それぞれ一対の櫛歯状の電極１６ａ、１６ｂからなり、これら一対の電極１６ａ、１６ｂが互いに接触しないように噛み合った状態で基板１５上に形成されている。また、これに対向するセンサシート１８の下面には、感圧層２０が電極部１６に離間対向して設けられている。なお、スペーサ１７は、電極部１６とセンサシート１８とのギャップを規制するとともに、電極部１６とセンサシート１８とを接着している。フェルト１９は、鍵２、３の下限ストッパの機能をも兼ねている。
【０００６】
この感圧センサ７では、鍵２、３のセンサ押圧部６によりフェルト１９を介してセンサシート１８が押圧されると、図４１に示すように、その押圧力に応じてセンサシート１８が撓み、その下面の感圧層２０が電極部１６に接触して一対の電極１６ａ、１６ｂを導通させ、このときの接触面積と接触圧力の大きさに応じて一対の電極１６ａ、１６ｂ間の電気抵抗値が変化し、この電気抵抗値に応じた検出信号を出力することにより、鍵２、３の押し込み力、つまり感圧センサ７に対する押圧力を検出する。すなわち、この感圧センサ７の基本的な特性は、図４２に示すように、鍵２、３による押圧力が弱くなるに従って、感圧層２０が電極部１６に接触する接触面積および接触圧力が小さくなるので、電気抵抗値が高くなり、逆に鍵２、３による押圧力が強くなるに従って、感圧層２０が電極部１６に接触する接触面積および接触圧力が大きくなるので、電気抵抗値が低くなり、これにより鍵２、３の押圧力に対する電気抵抗値が反比例する双曲線を描く。
【０００７】
このような電子鍵盤楽器の回路構成について、図４３を参照して説明する。
マイクロコンピュータの中央演算処理装置であるＣＰＵ２１は、ＲＯＭ２２にストアされたプログラムに従って電子鍵盤楽器のシステム全体を制御する。このＣＰＵ２１は、一定の周期による走査を行い、ゴムスイッチ５から押鍵操作に応じたスイッチ信号を音高データとして取り込む。感圧センサ７は、ＣＰＵ２１による一定周期の走査により、押鍵された鍵２、３の押圧力を電気抵抗値として検出する。この電気抵抗値は、抵抗電圧変換器２３により電圧信号に変換された上、Ａ／Ｄ変換器２４によりディジタル変換されて楽音制御信号としてＣＰＵ２１に取り込まれる。ＣＰＵ２１は、押鍵操作に基づいて楽音の発音指令を音源部２５に与えるとともに、押鍵操作に応じた音高の楽音信号を楽音制御信号に基づいて制御し、音色や音量などの各種の効果を付与する。音源部２５は、楽音制御信号に基づいて各種の効果が付与された楽音信号を発生する。この楽音信号は、Ｄ／Ａ変換器２６にてアナログ変換され、アンプ２７で増幅されてスピーカ２８から楽音として放音される。
【０００８】
このような電子鍵盤楽器では、図３７に示すように各コイルばね１０により各鍵２、３が押し上げられ、各鍵２、３のストッパ片１１が鍵盤シャーシ１の上限ストッパ１２に当接し、これにより各鍵２、３が初期位置（上限位置）に位置規制されている状態で、各鍵２、３のうち、例えば白鍵２がコイルばね１０のばね力に抗して押鍵されると、図３９（ａ）に示すように、白鍵２が鍵支持部８の支持軸９を中心に下方に回動し、その白鍵２のスイッチ押圧部４がゴムスイッチ５の各膨出ゴム部５ａを順次弾性変形させて各可動接点を各固定接点に順次接触させることにより、ゴムスイッチ５が押鍵された白鍵２に応じた音高のスイッチ信号を出力し、楽音の発音を開始する。この後、更に白鍵２が押し込まれると、感圧センサ７が白鍵２のセンサ押圧部６によって押圧され、図４１に示すように、感圧層２０が電極部１６に接触する。このときには、感圧センサ７に対する押圧力（白鍵２の押し込み力）に応じた接触面積および接触圧力で感圧層２０が一対の電極１６ａ、１６ｂを導通させる。これにより、感圧センサ７が導通状態に応じた電気抵抗値を検出信号として出力し、この電気抵抗値に応じた検出信号が楽音制御信号としてＣＰＵ２１に取り込まれる。ＣＰＵ２１は、その検出信号に基づいて音色や音量などを変化させ、発音中の音に各種の効果を付与して放音させ、これにより音の表現力を高めている。なお、黒鍵３も、白鍵２と同様に動作する。
【０００９】
【発明が解決しようとする課題】
しかしながら、このような電子鍵盤楽器では、図３９（ａ）および図３９（ｂ）に示すように、感圧センサ７が鍵支持部８の支持軸９から所定距離Ｓ０だけ離れた鍵盤シャーシ１上の所定位置に配置され、この状態で鍵２、３が押鍵されてセンサ押圧部６が感圧センサ７を押圧するときに、白鍵２と黒鍵３との各前端部２ａ、３ａが同じ力Ｆ０で押鍵されると、支持軸９から白鍵２の押鍵位置２ａまでの長さＳ１が黒鍵３の押鍵位置３ａまでの長さＳ２よりも長い（Ｓ１＞Ｓ２）ため、各鍵２、３の押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２に応じてそれぞれモーメントが異なってしまう。このため、白鍵２と黒鍵３とで感圧センサ７に加わる押圧力（押し込み力）Ｆ１、Ｆ２に差が生じ、白鍵２の押圧力Ｆ１よりも黒鍵３の押圧力Ｆ２が小さく（Ｆ２＜Ｆ１）なり、白鍵２と黒鍵３とを同じ力で押鍵しても、白鍵２と黒鍵３とで感圧センサ７により検出される電気抵抗値が異なってしまうという問題がある。
【００１０】
すなわち、この感圧センサ７では、白鍵２と黒鍵３とに対応する箇所がまったく同じ構成であるため、白鍵２と黒鍵３とでモーメントが異なると、図４４に示すように、白鍵２における感圧センサ７の検出特性（同図に実線で示す曲線Ｗ１）と、黒鍵３における感圧センサ７の検出特性（同図に２点鎖線で示す曲線Ｂ１）とが重なり合わずに、白鍵２における感圧センサ７の検出特性（曲線Ｗ１）と、黒鍵３における感圧センサ７の検出特性（曲線Ｂ１）とが押圧力の差（Ｆ１−Ｆ２）だけずれてしまい、これにより電気抵抗値に差が生じる。このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同じ力Ｆ０で押鍵しても、白鍵２と黒鍵３とで感圧センサ７による検出信号が異なり、発音中の音に付与される効果に差が生じ、良好に楽音を放音することができないという問題が生じる。
【００１１】
この発明の課題は、白鍵と黒鍵とでそのモーメントの差により押圧力が異なっても、同程度の検出信号が得らるようにすることである。
【００１２】
【課題を解決するための手段】
この発明は、白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、前記各鍵の下部に設けられた基板と、この基板上にスペーサを介して離間対向した状態で設けられ、押鍵時に前記鍵により押圧されて撓む可撓性部材と、前記基板と前記可撓性部材との対向領域内に互いに接触することなく設けられた一対の電極と、これら一対の電極のうちの少なくとも一方の電極に離間対向し、押鍵時に前記可撓性部材の撓みにより前記一対の電極を導通させる感圧層と、を有し、前記黒鍵に対応する箇所の前記スペーサの開口領域を、前記白鍵に対応する箇所の前記スペーサの開口領域よりも広く形成したことを特徴とする。この発明によれば、白鍵と黒鍵との各前端部を同程度の力で押鍵した際、白鍵と黒鍵との長さの違いにより白鍵と黒鍵とでモーメントが異なり、これにより白鍵に対応する箇所の可撓性部材に加わる押圧力と、黒鍵に対応する箇所の可撓性部材に加わる押圧力とが異なるが、黒鍵に対応する箇所のスペーサの開口領域を白鍵に対応する箇所のスペーサの開口領域よりも広く形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所の可撓性部材を白鍵に対応する箇所の可撓性部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。
【００１３】
また、請求項２に記載のごとく、白鍵に対応する箇所の可撓性部材の厚みを黒鍵に対応する箇所の可撓性部材の厚みよりも厚く形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所の可撓性部材を白鍵に対応する箇所の可撓性部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。
【００１４】
また、請求項３に記載のごとく、黒鍵に対応する箇所の周辺に位置する可撓性部材に、スリットを形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所の周辺に位置する可撓性部材のスリットにより、黒鍵に対応する箇所の可撓性部材を白鍵に対応する箇所の可撓性部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。さらに、請求項４に記載のごとく、スペーサを弾性材料で形成し、黒鍵に対応する箇所のスペーサの弾性係数を白鍵に対応する箇所のスペーサの弾性係数よりも小さく形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対する箇所のスペーサを白鍵に対する箇所のスペーサよりも大きく弾性変形させることができ、これにより同程度の検出信号を得ることができる。さらに、請求項５に記載のごとく、黒鍵に対応する箇所における電極とこれに離間対向する感圧層との間隔を、白鍵に対応する箇所における電極とこれに離間対向する感圧層との間隔よりも、狭く形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所における感圧層の一対の電極に対する接触面積および接触圧力を、白鍵に対応する箇所における感圧層の一対の電極に対する接触面積および接触圧力よりも、大きくすることができ、これにより同程度の検出信号を得ることができる。
【００１５】
また、本発明は請求項６に記載のごとく、白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、前記各鍵の下部に設けられた基板と、この基板上に設けられた一対の電極と、この基板上に開口部を有するスペーサを介して前記一対の電極と離間対向した位置に設けられ、その上面を押鍵時に前記鍵により押圧された際に下方に撓む可撓性部材と、この可撓性部材の上面に設けられ、押鍵時における鍵からの衝撃を吸収する緩衝部材と、この可撓性部材の下面に設けられ、押鍵時に前記可撓性部材の撓みにより前記一対の電極に接触して当該一対の電極同士を導通させる感圧層と、前記可撓性部材と前記緩衝部材との間に設けられるとともに、前記鍵を押鍵した際の前記可撓性部材の撓み度合いを、前記白鍵を押鍵した場合より前記黒鍵を押鍵した場合の方が大きくなるよう規制する規制部材と、を有し、前記規制部材は、前記鍵に対応する箇所に開口部が形成され、これら開口部のうち、前記黒鍵に対応する箇所の前記開口部が、前記白鍵に対応する箇所の前記開口部よりも広く形成されていることを特徴とする。
この発明によれば、規制部材が、鍵に対応する箇所に開口部が形成され、これら開口部のうち、黒鍵に対応する箇所の開口部が白鍵に対応する箇所の開口部よりも広く形成された構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、規制部材の開口部の大きさの違いにより、黒鍵に対応する箇所の可撓性部材を白鍵に対応する箇所の可撓性部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。また、請求項７に記載のごとく、規制部材が、可撓性を有する材料からなり、白鍵に対応する箇所の厚みが黒鍵に対応する箇所の厚みよりも厚く形成された構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所の規制部材を白鍵に対応する箇所の規制部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。
【００１６】
さらに、請求項８に記載のごとく、規制部材が、可撓性を有する材料からなり、黒鍵に対応する箇所の周辺位置にスリットが形成された構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の規制部材に加わる押圧力が白鍵に対応する箇所の規制部材に加わる押圧力よりも小さくても、スリットにより黒鍵に対応する箇所の規制部材を白鍵に対応する箇所の規制部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。規制部材が、可撓性を有する材料からなり、黒鍵に対応する箇所の周辺位置にスリットが形成された構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の規制部材に加わる押圧力が白鍵に対応する箇所の規制部材に加わる押圧力よりも小さくても、スリットにより黒鍵に対応する箇所の規制部材を白鍵に対応する箇所の規制部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。
【００１７】
さらに本発明は、請求項９に記載のごとく、白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、前記各鍵の下部に設けられた基板と、この基板上にスペーサを介して離間対向した状態で設けられ、押鍵時に前記鍵により押圧されて撓む可撓性部材と、前記基板と前記可撓性部材との対向領域内に互いに接触することなく設けられた一対の電極と、これら一対の電極のうちの少なくとも一方の電極に離間対向し、押鍵時に前記可撓性部材の撓みにより前記一対の電極を導通させる感圧層と、を有し、前記一対の電極は、それぞれ櫛歯状をなし、前記基板上に互いに接触することなく噛み合った状態で形成され、前記感圧層は、前記可撓性部材の下面に前記一対の電極に対し離間対向して設けられ、前記黒鍵に対応する箇所における前記一対の電極の噛み合い密度を、前記白鍵に対応する箇所における前記一対の電極の噛み合い密度よりも大きく形成したことを特徴とする。
この発明によれば、一対の電極が、それぞれ櫛歯状をなし、基板上に互いに接触することなく噛み合った状態で形成され、感圧層が可撓性部材の下面に一対の電極に対し離間対向して設けられ、調整手段が、黒鍵に対応する箇所における一対の電極の噛み合い密度を白鍵に対応する箇所における一対の電極の噛み合い密度よりも大きく形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所における感圧層の一対の電極に対する導通密度を、白鍵に対応する箇所における感圧層の一対の電極に対する導通密度よりも、大きくすることができ、これにより同程度の検出信号を得ることができる。
【００１８】
【発明の実施の形態】
［第１実施形態］
以下、図１〜図４を参照して、この発明の感圧センサの第１実施形態について説明する。なお、図３７〜図４４に示された従来例と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ３０は、スペーサ３１の開口領域が白鍵２と黒鍵３とに対応する箇所で異なり、これ以外は従来例と同じ構成になっている。
すなわち、スペーサ３１は、図１および図２に示すように、基板１５の両側辺上に鍵２、３の配列方向に沿って設けられ、黒鍵３に対応する箇所における鍵２、３の配列方向と直交する方向の対向部分に切欠部３２がそれぞれ設けられている。従って、このスペーサ３１は、鍵２、３の配列方向と直交する方向におけるスペーサ３１の間隔のうち、黒鍵３に対応する箇所のスペーサ３１の間隔Ｌ２が、白鍵２に対応する箇所のスペーサ３１の間隔Ｌ１よりも、両側の２つの切欠部３２だけ広く（Ｌ２＞Ｌ１）形成された構成になっている。これにより、スペーサ３１は、黒鍵３に対応する箇所の開口領域が白鍵２に対応する箇所のスペーサ３１の開口領域よりも広く形成されている。
【００１９】
このような感圧センサ３０では、黒鍵３に対応する箇所のスペーサ３１の間隔Ｌ２が白鍵２に対応する箇所のスペーサ３１の間隔Ｌ１よりも広く形成されているので、鍵２、３のセンサ押圧部６によって緩衝部材であるフェルト１９が同じ力で押圧されると、黒鍵３に対応する箇所の可撓性部材であるセンサシート１８が、白鍵２に対応する箇所のセンサシート１８よりも大きく撓むことになる。
これは、図３に示すように、センサシート１８が固定梁をなし、その両端がスペーサ３１上に固定され、そのスペーサ３１間に対応するセンサシート１８が等分布荷重ｗ（Kg/cm）を受ける場合の梁の撓みνに相当するからである。
【００２０】
この梁の撓みνに関する一般式は、
ν＝｛ｗｘ2／２４ＥＩ｝（Ｌ−ｘ）2 …………（１）
である。ただし、Ｌはスペーサ３１の間隔、ｘはスペーサ３１の間隔Ｌ内におけるセンサシート１８の任意の位置、Ｅは弾性係数（ヤング率）、Ｉは断面二次モーメントである。この断面二次モーメントＩは、断面形状が長方形であるから、
Ｉ＝（１／１２）ｂｈ3 …………（２）
である。ただし、ｂは鍵２、３の配列方向に沿うスペーサ３１の開口領域の幅、ｈはセンサシート１８の厚みである。
この（２）式を（１）式に代入すると、
ν＝｛ｗｘ2／２Ｅｂｈ3｝（Ｌ−ｘ）2 …………（３）
となる。なお、最大の撓みνmaxは、スペーサ３１の間隔Ｌ内におけるセンサシート１８の中間位置（Ｌ／２）であるから、

Figure 0003757666
が成立する。
この結果、上記（３）、（４）式により、スペーサ３１の間隔Ｌが大きいほど、センサシート１８の撓み量が多くなることがわかる。
【００２１】
従って、この感圧センサ３０では、黒鍵３に対応する箇所のスペーサ３１の間隔Ｌ２が白鍵２に対応する箇所のスペーサ３１の間隔Ｌ１よりも、両側２つの切欠部３２だけ広く（Ｌ２＞Ｌ１）形成されているので、黒鍵３に対応する箇所のセンサシート１８が、白鍵２に対応する箇所のセンサシート１８よりも大きく撓むことになる。このため、この感圧センサ３０では、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所のセンサシート１８に加わる押圧力Ｆ２が白鍵２に対応する箇所のセンサシート１８に加わる押圧力Ｆ１よりも小さく（Ｆ２＜Ｆ１）ても、黒鍵３に対応する箇所のセンサシート１８を白鍵３に対応する箇所のセンサシート１８よりも大きく撓ませることができ、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、黒鍵３に対応する箇所のスペーサ３１の２つの切欠部３２の切り込み量を調節することにより、感圧層２０による電極部１６の導通状態を同程度にすることができる。
【００２２】
すなわち、この感圧センサ３０では、黒鍵３に対応する箇所のスペーサ３１の２つの切欠部３２の切り込み量を調節することにより、白鍵２と黒鍵３とでモーメントが異なっても、図４に示すように、白鍵２における感圧センサ３０の検出特性（同図に実線で示す曲線Ｗ２）と、黒鍵３における感圧センサ３０の検出特性（同図に２点鎖線で示す曲線Ｂ２）とが同じ曲線でほぼ同じ位置に一致する。これにより、黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、感圧層２０が電極部１６に接触する接触面積および接触圧力がほぼ同じになり、同程度の電気抵抗値を得ることができる。このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同じ力Ｆ０で押鍵しても、白鍵２と黒鍵３とで感圧センサ３０の導通状態が同程度となり、感圧センサ３０により同程度の電気抵抗値を出力することができ、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
【００２３】
なお、上記第１実施形態では、黒鍵３に対応する箇所におけるスペーサ３１の対向部分にそれぞれ切欠部３２を設けたが、これに限らず、例えば、図５（ａ）または図５（ｂ）に示す各変形例のように構成しても良い。
図５（ａ）に示された第１変形例は、鍵２、３の配列方向に沿って設けられた両側のスペーサ３１ａ、３１ｂのうち、鍵２、３の前側（同図では左側）に位置するスペーサ３１ａの幅（鍵２、３の配列方向と直交する方向の長さ）を狭く形成し、鍵２、３の後側（同図では右側）に位置するスペーサ３１ｂの幅を広く形成し、この幅の広いスペーサ３１ｂのうち、黒鍵３に対応する箇所の対向部分のみに切欠部３２を形成し、これにより黒鍵３に対応する箇所のスペーサ３１ａ、３１ｂの間隔Ｌ２を、白鍵２に対応する箇所のスペーサ３１ａ、３１ｂの間隔Ｌ１よりも広く形成し、黒鍵３に対応する箇所のスペーサ３１ａ、３１ｂの開口領域を白鍵２に対応する箇所のスペーサ３１ａ、３１ｂの開口領域よりも広く形成した構成になっている。
また、図５（ｂ）に示された第２変形例は、第１変形例において、黒鍵３に対応する箇所の切欠部３２を鍵２、３の配列方向と直交する方向に貫通させて形成した構成になっている。
このような第１、第２変形例においても、第１実施形態と同様の作用効果があることは言うまでもない。
【００２４】
［第２実施形態］
次に、図６〜図８を参照して、この発明の感圧センサの第２実施形態について説明する。この場合にも、図３７〜図４４に示された従来例と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ３５は、スペーサ３６の開口領域が白鍵２と黒鍵３とに対応する箇所で異なり、これ以外は従来例と同じ構成になっている。
すなわち、スペーサ３６は、図６〜図８に示すように、基板１５の両側辺上に鍵２、３の配列方向に沿って同じ形状で設けられ、各鍵２、３に対応する箇所における対向部分にそれぞれ切欠部３７、３８が設けられ、これら切欠部３７、３８に対応する箇所のスペーサ３６の各間隔Ｌが同じ長さに形成されている。
この場合、各鍵２、３に対応する箇所の切欠部３７、３８における鍵２、３の配列方向の長さｂ１、ｂ２のうち、黒鍵３に対応する箇所の切欠部３８の長さｂ２は、白鍵２に対応する箇所の切欠部３７の長さｂ１よりも、長く（ｂ２＞ｂ１）形成されている。これにより、スペーサ３６は、黒鍵３に対応する箇所の開口領域が白鍵２に対応する箇所のスペーサ３６の開口領域よりも広く形成されている。
なお、各鍵２、３のセンサ押圧部６は、立て板状に形成され、各鍵２、３の配列方向と直交する方向の長さｍ１がスペーサ３６の各間隔Ｌよりも充分に長く（ｍ１＞Ｌ）形成され、かつ各鍵２、３の配列方向の長さｍ２が白鍵２に対応する箇所の切欠部３７の長さｂ１よりも、充分に短く（ｍ２＜ｂ１＜ｂ２）形成されている。
【００２５】
このような感圧センサ３５では、黒鍵３に対応する箇所のスペーサ３６の切欠部３８の長さｂ２が白鍵２に対応する箇所の切欠部３７の長さｂ１よりも長く（ｂ２＞ｂ１）形成され、これにより黒鍵３に対応する箇所の開口領域が白鍵２に対応する箇所のスペーサ３６の開口領域よりも広く形成されているので、鍵２、３のセンサ押圧部６によって緩衝部材であるフェルト１９が同じ力で押圧されると、黒鍵３に対応する箇所の可撓性部材であるセンサシート１８が、白鍵２に対応する箇所のセンサシート１８よりも大きく撓むことになる。
これは、各鍵２、３のセンサ押圧部６における各鍵２、３の配列方向の長さｍ２が、白鍵２に対応する箇所の切欠部３７の長さｂ１よりも、充分に短く（ｍ２＜ｂ１＜ｂ２）形成されているため、このセンサ押圧部６で各鍵２、３に対応する箇所のフェルト１９が同じ力で押圧されると、図７に示すように、黒鍵３に対応する箇所のスペーサ３６の切欠部３８の長さｂ２が白鍵２に対応する箇所の切欠部３７の長さｂ１よりも長い（ｂ２＞ｂ１）ので、黒鍵３に対応する箇所のセンサシート１８が白鍵２に対応する箇所のセンサシート１８よりも鍵２、３の配列方向に大きく伸びて撓むことになるからである。
【００２６】
このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所のセンサシート１８に加わる押圧力Ｆ２が白鍵２に対応する箇所のセンサシート１８に加わる押圧力Ｆ１よりも小さくても、黒鍵３に対応する箇所のセンサシート１８を白鍵３に対応する箇所のセンサシート１８よりも大きく撓ませることができ、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、白鍵２と黒鍵３に対応する箇所のスペーサ３６の切欠部３７、３８の長さｂ１、ｂ２を適宜設定して、白鍵２と黒鍵３とに対応する箇所の各開口領域の広さを調節することにより、感圧層２０による電極部１６の導通状態を同程度にすることができる。この結果、第１実施形態と同様、感圧センサ３５が同程度の電気抵抗値を出力し、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
【００２７】
［第３実施形態］
次に、図９〜図１１を参照して、この発明の感圧センサの第３実施形態について説明する。この場合にも、図３７〜図４４に示された従来例と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ４０は、可撓性部材であるセンサシート４１の厚みが白鍵２と黒鍵３とに対応する箇所で異なり、これ以外は従来例と同じ構成になっている。すなわち、センサシート４１は、図９および図１０に示すように、白鍵２に対応する箇所の上面に白鍵２のセンサ押圧部６で押圧される平板部４２が一体に形成され、これにより白鍵２に対応する箇所の厚みｈ１がこれ以外の箇所、つまり黒鍵３に対応する箇所の厚みｈ２よりも厚く（ｈ１＞ｈ２）形成されている。この場合、平板部４２は、鍵２、３の配列方向と直交する方向の長さｎ１がこれと同方向におけるスペーサ１７の間隔Ｌよりも長く（ｎ１＞Ｌ）形成され、これにより鍵２、３の配列方向と直交する方向における平板部４２の両端部がスペーサ１７上に位置している。また、この平板部４２は、鍵２、３の配列方向の長さｎ２がこれと同方向における鍵２、３のセンサ押圧部６の長さｍ２よりも長く（ｎ２＞ｍ２）、かつその箇所における白鍵２の幅よりも短く形成されている。
【００２８】
このような感圧センサ４０では、白鍵２に対応する箇所のセンサシート４１の厚みｈ１が黒鍵３に対応する箇所のセンサシート４１の厚みｈ２よりも厚く（ｈ１＞ｈ２）形成されているので、鍵２、３のセンサ押圧部６によって緩衝部材であるフェルト１９が同じ力で押圧されると、白鍵２に対応する箇所のセンサシート４１が黒鍵３に対応する箇所のセンサシート４１よりも撓み量が小さくなる。これは、第１実施形態における撓みνの一般式、および最大撓みνmaxの式、
ν＝｛ｗｘ2／２Ｅｂｈ3｝（Ｌ−ｘ）2 …………（３）
νmax＝｛ｗＬ4／３２Ｅｂｈ3｝ …………（４）
から明らかなように、センサシート４１の厚みｈが厚いほど、センサシート４１の撓み（ν、νmax）が小さいからである。
【００２９】
このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所のセンサシート４１に加わる押圧力Ｆ２が白鍵２に対応する箇所のセンサシート４１に加わる押圧力Ｆ１よりも小さくても、黒鍵３に対応する箇所のセンサシート４１を白鍵３に対応する箇所のセンサシート４１よりも大きく撓ませることができ、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、白鍵２と黒鍵３とに対応する箇所のセンサシート４１の厚みｈ１、ｈ２の差（ｈ１−ｈ２）を適宜設定することにより、感圧層２０による電極部１６の導通状態を同程度にすることができる。この結果、第１実施形態と同様、感圧センサ４０が同程度の電気抵抗値を出力し、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
【００３０】
なお、上記第３実施形態では、白鍵２に対応する箇所のセンサシート４１の上面に平板部４２を形成したが、これに限らず、例えば、図１２に示すように、白鍵２に対応する箇所のセンサシート４１の上面に山形部４３をその頂点が白鍵２のセンサ押圧部６に対応するように一体に形成し、白鍵２に対応する箇所の厚みｈ１がこれ以外の黒鍵３に対応する箇所を含む厚みｈ２よりも厚く（ｈ１＞ｈ２）なるように形成した構成でも良い。このように構成しても、第３実施形態と同様の作用効果がある。
また、上記第３実施形態およびその変形例では、センサシート４１上に平板部４２または山形部４３を一体に形成したが、必ずしも一体に形成する必要はなく、別々に形成しても良い。
【００３１】
［第４実施形態］
次に、図１３〜図１５を参照して、この発明の感圧センサの第４実施形態について説明する。この場合にも、図３７〜図４４に示された従来例と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ４５は、可撓性部材であるセンサシート１８と緩衝部材であるフェルト１９との間に規制部材４６を配置した構成で、これ以外は従来例と同じ構成になっている。
すなわち、規制部材４６は、図１３〜図１５に示すように、センサシート１８の両側辺上に鍵２、３の配列方向に沿うスペーサ１７とほぼ対応して設けられ、黒鍵３に対応する箇所における鍵２、３の配列方向と直交する方向の対向部分に切欠部４７がそれぞれ設けられた構成になっている。従って、この規制部材４６は、図１５に示すように、鍵２、３の配列方向と直交する方向における規制部材４６の間隔のうち、黒鍵３に対応する箇所の規制部材４６の間隔Ｌ２が、白鍵２に対応する箇所の規制部材４６の間隔Ｌ１よりも、両側の２つの切欠部４７だけ広く（Ｌ２＞Ｌ１）形成された構成になっている。これにより、規制部材４６は、黒鍵３に対応する箇所の開口領域が白鍵２に対応する箇所の開口領域よりも広く形成され、これら各開口領域内にフェルト１９の下部が挿入されて配置されている。
【００３２】
このような感圧センサ４５では、黒鍵３に対応する箇所の規制部材４６の間隔Ｌ２が、白鍵２に対応する箇所の規制部材４６の間隔Ｌ１よりも、両側の２つの切欠部４７だけ広く（Ｌ２＞Ｌ１）形成され、これにより黒鍵３に対応する箇所の規制部材４６の開口領域が白鍵２に対応する箇所の規制部材４６の開口領域よりも広く形成されているので、鍵２、３のセンサ押圧部６によって緩衝部材であるフェルト１９が同じ力で押圧されると、黒鍵３に対応する箇所のセンサシート１８が、白鍵２に対応する箇所のセンサシート１８よりも大きく撓むことになる。
これは、黒鍵３に対応する箇所の規制部材４６の開口領域が白鍵２に対応する箇所の規制部材４６の開口領域よりも広く形成され、これら各開口領域内にフェルト１９の下部が挿入されて配置されているので、センサ押圧部６で各鍵２、３に対応する箇所のフェルト１９が同じ力で押圧されると、フェルト１９が規制部材４６により規制され、黒鍵３に対応する箇所のフェルト１９によるセンサシート１８の押圧面積が、白鍵２に対応する箇所のフェルト１９によるセンサシート１８の押圧面積よりも広くなり、このため黒鍵３に対応する箇所のセンサシート１８が白鍵２に対応する箇所のセンサシート１８よりも大きく撓むことになるからである。
【００３３】
このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所のフェルト１９に加わる押圧力Ｆ２が白鍵２に対応する箇所のフェルト１９に加わる押圧力Ｆ１よりも小さくても、規制部材４６がフェルト１９を規制することにより、黒鍵３に対応する箇所のセンサシート１８を白鍵３に対応する箇所のセンサシート１８よりも大きく撓ませることができ、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、白鍵２と黒鍵３に対応する箇所の規制部材４６の切欠部４７の切り込み量を適宜設定して、白鍵２と黒鍵３とに対応する箇所の各開口領域の広さを調節することにより、感圧層２０による電極部１６の導通状態を同程度にすることができる。この結果、第１実施形態と同様、感圧センサ３５が同程度の電気抵抗値を出力し、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
【００３４】
なお、上記第４実施形態では、黒鍵３に対応する箇所の規制部材４６に切欠部４７を設け、これにより黒鍵３に対応する箇所の規制部材４６の開口領域を白鍵２に対応する箇所の規制部材４６の開口領域よりも広く形成したが、これに限らず、例えば、図１６に示すように、各鍵２、３に対応する箇所の規制部材４８にそれぞれ切欠部４８ａ、４８ｂを設け、これら切欠部４８ａ、４８ｂに対応する箇所の規制部材４８の各間隔Ｌを同じ長さに形成した上、各切欠部４８ａ、４８ｂにおける鍵２、３の配列方向の長さｂ１、ｂ２のうち、黒鍵３に対応する箇所の切欠部４８ｂの長さｂ２を、白鍵２に対応する箇所の切欠部４８ａの長さｂ１よりも、長く（ｂ２＞ｂ１）形成し、これにより黒鍵３に対応する箇所の規制部材４８の開口領域を白鍵２に対応する箇所の規制部材４８の開口領域よりも広く形成した構成でも良い。このように構成しても、第４実施形態と同様の作用効果がある。
【００３５】
［第５実施形態］
次に、図１７〜図１９を参照して、この発明の感圧センサの第５実施形態について説明する。この場合にも、図３７〜図４４に示された従来例と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ５０は、可撓性部材であるセンサシート１８と緩衝部材であるフェルト１９との間に可撓性を有する規制部材５１を配置し、この規制部材５１の厚みを白鍵２と黒鍵３とに対応する箇所で異ならせた構成で、これ以外は従来例と同じ構成になっている。
すなわち、規制部材５１は、図１７〜図１９に示すように、白鍵２に対応する箇所のセンサシート１８の上面に平板部５２が一体に形成され、これにより白鍵２に対応する箇所の厚みｈ３がこれ以外の箇所、つまり黒鍵３に対応する箇所の厚みｈ４よりも厚く（ｈ３＞ｈ４）形成されている。この場合、平板部５２は、鍵２、３の配列方向と直交する方向の長さｎ３がこれと同方向におけるスペーサ１７の間隔Ｌよりも長く（ｎ３＞Ｌ）形成され、これにより鍵２、３の配列方向と直交する方向における平板部５２の両端部がスペーサ１７上に位置している。また、この平板部５２は、鍵２、３の配列方向の長さｎ４がこれと同方向における鍵２、３のセンサ押圧部６の長さｍ２よりも長く（ｎ４＞ｍ２）形成され、かつその箇所における白鍵２の幅よりも短く形成されている。
【００３６】
このような感圧センサ５０では、白鍵２に対応する箇所の規制部材５１の厚みｈ３が黒鍵３に対応する箇所の規制部材５１の厚みｈ４よりも厚く（ｈ３＞ｈ４）形成されているので、鍵２、３のセンサ押圧部６によって緩衝部材であるフェルト１９が同じ力で押圧されると、白鍵２に対応する箇所の規制部材５１が黒鍵３に対応する箇所の規制部材５１よりも撓み量が小さくなる。これは、第１実施形態における撓みνの一般式、および最大撓みνmaxの式、
ν＝｛ｗｘ2／２Ｅｂｈ3｝（Ｌ−ｘ）2 …………（３）
νmax＝｛ｗＬ4／３２Ｅｂｈ3｝ …………（４）
から明らかなように、センサシート４１の厚みｈが厚いほど、規制部材５１の撓み（ν、νmax）が小さいからである。
【００３７】
このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所の規制部材５１に加わる押圧力Ｆ２が白鍵２に対応する箇所の規制部材５１に加わる押圧力Ｆ１よりも小さくても、黒鍵３に対応する箇所の規制部材５１が白鍵３に対応する箇所の規制部材５１よりも大きく撓むことになり、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、白鍵２と黒鍵３とに対応する箇所の規制部材５１の厚みｈ３、ｈ４を適宜設定して、白鍵２と黒鍵３とに対応する箇所のセンサシート１８の撓み量をほぼ同じにすることにより、感圧層２０による電極部１６の導通状態を同程度にすることができる。この結果、第１実施形態と同様、感圧センサ５０が同程度の電気抵抗値を出力し、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
【００３８】
［第６実施形態］
次に、図２０〜図２２を参照して、この発明の感圧センサの第６実施形態について説明する。この場合にも、図３７〜図４４に示された従来例と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ５５は、可撓性部材であるセンサシート１８と緩衝部材であるフェルト１９との間に可撓性を有する規制部材５６を配置し、この規制部材５６に矩形状の開口部５７を白鍵２と対応する一部の箇所を除いて形成した構成で、これ以外は従来例と同じ構成になっている。
すなわち、規制部材５６は、図２０〜図２２に示すように、白鍵２のセンサ押圧部６に対応する箇所付近を除く箇所、つまり少なくとも黒鍵３に対応する箇所に開口部５７を鍵２、３の配列方向に沿って形成した構成になっている。この場合、開口部５７は、鍵２、３の配列方向と直交する方向の長さｎ５がこれと同方向におけるスペーサ１７の間隔Ｌと同じ長さ（ｎ５＝Ｌ）で形成されているとともに、鍵２、３の配列方向の長さｎ６がこれと同方向における黒鍵３の幅よりも長く形成され、これら黒鍵３に対応する箇所の各開口部５７内にフェルト１９の下部が挿入されて配置されている。
【００３９】
このような感圧センサ５５では、黒鍵３に対応する箇所の規制部材５６に開口部５７が形成され、白鍵２のセンサ押圧部６に対応する箇所付近の規制部材５６に開口部５７が形成されていないので、鍵２、３のセンサ押圧部６によってフェルト１９が同じ力で押圧されると、黒鍵３に対応する箇所のセンサシート１８が、白鍵２に対応する箇所のセンサシート１８よりも大きく撓むことになる。
これは、黒鍵３に対応する箇所では、フェルト１９が規制部材５６の開口部５７を通して直接センサシート１８を押圧するが、白鍵２に対応する箇所では、フェルト１９が規制部材５６を押圧して撓ませた上、この規制部材５６がセンサシート１８を押圧するので、センサ押圧部６により各鍵２、３に対応する箇所のフェルト１９が同じ力で押圧されると、黒鍵３に対応する箇所のセンサシート１８が白鍵２に対応する箇所のセンサシート１８よりも大きく撓むことになるからである。
【００４０】
このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３までの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所のフェルト１９に加わる押圧力Ｆ２が白鍵２に対応する箇所のフェルト１９に加わる押圧力Ｆ１よりも小さくても、規制部材５６の開口部５７がフェルト１９を規制することにより、黒鍵３に対応する箇所のセンサシート１８を白鍵３に対応する箇所のセンサシート１８よりも大きく撓ませることができ、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、白鍵２と黒鍵３に対応する箇所の規制部材５６の開口部５７の開口量を適宜設定して、白鍵２と黒鍵３とに対応する箇所の各開口領域の広さを調節することにより、感圧層２０による電極部１６の導通状態を同程度にすることができる。この結果、第１実施形態と同様、感圧センサ３５が同程度の電気抵抗値を出力し、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
【００４１】
なお、上記第６実施形態では、白鍵２のセンサ押圧部６に対応する箇所付近を除く箇所、つまり黒鍵３に対応する箇所の規制部材５６に開口部５７を形成したが、これに限らず、例えば、図２３に示すように、黒鍵３に対応する箇所の周辺位置、つまり黒鍵３に対応する箇所における鍵２、３の配列方向の周辺両側に位置する可撓性を有する規制部材５８にスリット５９を鍵２、３の配列方向と直交する方向に形成した構成でも良い。このように構成すれば、黒鍵３に対応する箇所の規制部材５８に形成されたスリット５９により、黒鍵３に対応する箇所の規制部材５８の断面二次モーメントＩが
Ｉ＝（１／１２）ｂｈ3 …………（２）
であるから、この（２）式のｂ（鍵２、３の配列方向に沿う規制部材５８の幅）が小さくなり、これにより断面二次モーメントＩが小さくなる。このため、第１実施形態の（３）、（４）式により、黒鍵３に対応する箇所の規制部材５８が、白鍵２に対応する箇所の規制部材５８よりも撓みやすくなり、このため第１実施形態と同様の効果がある。
【００４２】
［第７実施形態］
次に、図２４および図２５を参照して、この発明の感圧センサの第７実施形態について説明する。この場合にも、図３７〜図４４に示された従来例と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ６０は、スペーサ６１を弾性部材で形成し、かつそのスペーサ６１の弾性係数を白鍵２と黒鍵３とに対応する箇所で異ならせた構成で、これ以外は従来例と同じ構成になっている。
すなわち、このスペーサ６１は、ゴムなどの弾性材料からなり、基板１５の両側辺上に鍵２、３の配列方向に沿ってそれぞれ設けられ、かつ黒鍵３に対応する箇所のスペーサ６１ｂの弾性係数が、白鍵２に対応する箇所のスペーサ６１ａの弾性係数よりも小さく形成された構成なっている。
このような感圧センサ６０では、鍵２、３のセンサ押圧部６によってフェルト１９が同じ力で押圧されると、黒鍵３に対応する箇所のスペーサ６１ｂの弾性係数が、白鍵２に対応する箇所のスペーサ６１ａの弾性係数よりも小さいので、黒鍵３に対応する箇所のスペーサ６１ｂが白鍵２に対応する箇所のスペーサ６１ａよりも大きく収縮変形し、これにより黒鍵３に対応する箇所のセンサシート１８が、白鍵２に対応する箇所のセンサシート１８よりも大きく押し下げられる。
【００４３】
このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所のセンサシート１８に加わる押圧力Ｆ２が白鍵２に対応する箇所のセンサシート１８に加わる押圧力Ｆ１よりも小さくても、黒鍵３に対応する箇所のセンサシート１８を白鍵３に対応する箇所のセンサシート１８よりも大きく押し下げることができ、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、白鍵２と黒鍵３に対応する箇所のスペーサ６１ａ、６１ｂの弾性係数を適宜設定して、白鍵２と黒鍵３とに対応する箇所のスペーサ６１ａ、６１ｂの変形量を調節することにより、感圧層２０による電極部１６の導通状態を同程度にすることができる。この結果、第１実施形態と同様、感圧センサ３５が同程度の電気抵抗値を出力し、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
なお、上記第７実施形態では、両辺側のスペーサ６１の弾性係数を白鍵２と黒鍵３とに対応する箇所で異ならせたが、これに限らず、白鍵２と黒鍵３とに対応する箇所で弾性係数が異なるスペーサ６１を片側のみに設けただけでも良い。
【００４４】
［第８実施形態］
次に、図２６〜図２９を参照して、この発明の感圧センサの第８実施形態について説明する。この場合にも、図３７〜図４４に示された従来例と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ６５は、電極部１６と感圧層２０との間隔を白鍵２と黒鍵３とに対応する箇所で異ならせた構成で、これ以外は従来例と同じ構成になっている。
すなわち、この感圧センサ６５は、図２６〜図２８に示すように、黒鍵３に対応する箇所のみに位置する基板１５上に絶縁板６６を設け、この絶縁板６６上を乗り越えて電極部１６を基板１５上に形成し、これにより黒鍵３に対応する箇所における電極部１６と感圧層２０との間隔Ｈ２を、白鍵２に対応する箇所における電極部１６と感圧層２０との間隔Ｈ１よりも狭く（Ｈ１＞Ｈ２）形成した構成になっている。この場合、絶縁板６６は、その厚さが電極部１６の厚さよりも厚く形成されている。
【００４５】
このような感圧センサ６５では、黒鍵３に対応する箇所の基板１５上に設けられた絶縁板６６により、黒鍵３に対応する箇所における電極部１６と感圧層２０との間隔Ｈ２が、白鍵２に対応する箇所における電極部１６と感圧層２０との間隔Ｈ１よりも狭く（Ｈ２＜Ｈ１）形成されているので、鍵２、３のセンサ押圧部６によってフェルト１９が同じ力で押圧されて、白鍵２と黒鍵３とに対応する箇所のセンサシート１８が同程度撓むと、黒鍵３に対応する箇所の感圧層２０が白鍵２に対応する箇所の感圧層２０よりも電極部１６に対する接触面積および接触圧力が大きくなり、これにより黒鍵３に対応する箇所の電気抵抗値を白鍵に対応する箇所の電気抵抗値よりも小さくすることができる。
すなわち、この感圧センサ６５では、図２９に示すように、黒鍵３における感圧センサ６５の検出特性（同図に２点鎖線で示す曲線Ｂ３）が、白鍵２における感圧センサ６５の検出特性（同図に実線で示す曲線Ｗ３）よりも、中間部分において上方にずれているので、黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、各曲線Ｂ３、Ｗ３の中間部分では同程度の電気抵抗値を得ることができる。
【００４６】
このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所のセンサシート１８に加わる押圧力Ｆ２が白鍵２に対応する箇所のセンサシート１８に加わる押圧力Ｆ１よりも小さくなるので、図２９に示すように、感圧層２０を電極部１６に同じタイミングで接触させることができる。しかも、黒鍵３に対応する箇所のセンサシート１８に加わる押圧力Ｆ２が白鍵２に対応する箇所のセンサシート１８に加わる押圧力Ｆ１よりも小さくても、黒鍵３に対応する箇所の電気抵抗値を白鍵３に対応する箇所の電気抵抗値よりも小さくすることができ、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、白鍵２と黒鍵３とに対応する箇所における電極部１６と感圧層２０との間隔Ｈ１、Ｈ２を適宜設定して、白鍵２と黒鍵３とに対応する箇所の電気抵抗値を調節することにより、感圧層２０による電極部１６の導通状態を同程度にすることができる。この結果、第１実施形態と同様、感圧センサ３５が同程度の電気抵抗値を出力し、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
【００４７】
なお、上記第８実施形態では、黒鍵３に対応する箇所の基板１５上に絶縁板６６を設け、この絶縁板６６を乗り越えて電極部１６を基板１５上に形成したが、これに限らず、例えば、黒鍵３に対応する箇所の感圧層２０の厚みを厚く形成して、黒鍵３に対応する箇所の感圧層２０と電極部１６との間隔を、白鍵２に対応する箇所の感圧層２０と電極部１６との間隔よりも狭く形成しても良く、また黒鍵３に対応する箇所のセンサシート１８の厚みを厚く形成して、黒鍵３に対応する箇所の感圧層２０と電極部１６との間隔を、白鍵２に対応する箇所の感圧層２０と電極部１６との間隔よりも狭く形成しても良い。この場合には、センサシート１８の撓みを考慮して、白鍵２と黒鍵３とで感圧層２０と電極部１６との間隔の大きくすれば良い。
【００４８】
［第９実施形態］
次に、図３０〜図３３を参照して、この発明の感圧センサの第９実施形態について説明する。この場合にも、図３７〜図４４に示された従来例と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ７０は、黒鍵３に対応する箇所における電極部７１の密度を白鍵２に対応する箇所における電極部７１の密度よりも大きく形成した構成で、これ以外は従来例と同じ構成になっている。
すなわち、この感圧センサ７０は、図３０および図３１に示すように、黒鍵３に対応する箇所に位置する電極部７１の一対の電極７１ａ、７１ｂの間隔を、白鍵２に対応する箇所に位置する電極部７１の一対の電極７１ａ、７１ｂの間隔よりも、狭く形成し、これにより黒鍵３に対応する箇所における電極部７１の密度が、白鍵２に対応する箇所における電極部７１の密度よりも大きく形成されている。
【００４９】
このような感圧センサ７０では、黒鍵３に対応する箇所における電極部７１の密度を白鍵２に対応する箇所における電極部７１の密度よりも大きく形成したので、図３２に示すように、鍵２、３のセンサ押圧部６によってフェルト１９が同じ力で押圧されて、白鍵２と黒鍵３とに対応する箇所のセンサシート１８が同程度撓むと、白鍵２と黒鍵３とに対応する箇所における電極部７１に対する感圧層２０の接触面積が同程度であっても、白鍵２と黒鍵３とにおける電極部７１の密度の違いにより、黒鍵３に対応する箇所の電気抵抗値を白鍵２に対応する箇所の電気抵抗値よりも小さくすることができる。
すなわち、この感圧センサ７０では、図３３に示すように、黒鍵３における感圧センサ７０の検出特性（同図に２点鎖線で示す曲線Ｂ４）が、白鍵２における感圧センサ７０の検出特性（同図に実線で示す曲線Ｗ４）よりも、押圧力の弱い側（同図の左側）において、押鍵力の強い方向（同図の右方向）にずれることになり、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、各曲線Ｂ４、Ｗ４がずれていることにより同程度の電気抵抗値を得ることができる。
【００５０】
このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所のセンサシート１８に加わる押圧力Ｆ２が白鍵２に対応する箇所のセンサシート１８に加わる押圧力Ｆ１よりも小さくても、黒鍵３に対応する箇所の電気抵抗値を白鍵３に対応する箇所の電気抵抗値よりも小さくすることができ、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、白鍵２と黒鍵３とに対応する箇所における電極部７１の密度を適宜設定して、白鍵２と黒鍵３とに対応する箇所の電気抵抗値を調節することにより、感圧層２０による電極部７１の導通状態を同程度にすることができる。この結果、第１実施形態と同様、感圧センサ７０が同程度の電気抵抗値を出力し、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
【００５１】
［第１０実施形態］
次に、図３４および図３５を参照して、この発明の感圧センサの第１０実施形態について説明する。この場合には、図３０〜図３３に示された第９実施形態と同一部分には同一符号を付し、その説明は省略する。
この感圧センサ７５は、黒鍵３に対応する箇所の周辺位置におけるセンサシート１８にスリット７６を形成した構成で、これ以外は第９実施形態と同じ構成になっている。
すなわち、この感圧センサ７５は、黒鍵３に対応する箇所の電極部７１の密度を白鍵２に対応する箇所の電極部７１の密度よりも大きく形成するとともに、黒鍵３に対応する箇所における鍵２、３の配列方向の周辺両側に位置するセンサシート１８にスリット７６を鍵２、３の配列方向と直交する方向に形成し、これにより黒鍵３に対応する箇所のセンサシート１８が、白鍵２に対応する箇所のセンサシート１８よりも撓みやすくした構成になっている。この場合、各スリット７６は、鍵２、３の配列方向と直交する方向における長さが、これと同方向におけるスペーサ１７の間隔Ｌとほぼ同じ長さか、それよりも僅かに長く形成されている。
【００５２】
このような感圧センサ７５では、黒鍵３に対応する箇所の周辺に位置するセンサシート１８にスリット７６を形成したことにより、黒鍵３に対応する箇所のセンサシート１８の断面二次モーメントＩが
Ｉ＝（１／１２）ｂｈ3 …………（２）
であるから、この（２）式のｂ（鍵２、３の配列方向に沿うセンサシート１８の幅）が小さくなり、これにより断面二次モーメントＩが小さくなり、第１実施形態の（３）、（４）式により、黒鍵３に対応する箇所のセンサシート１８の撓み量が多くなる。このため、鍵２、３のセンサ押圧部６によってフェルト１９が同じ力で押圧されると、黒鍵３に対応する箇所のセンサシート１８が白鍵に対応する箇所のセンサシート１８よりも大きく撓み、しかも黒鍵３に対応する箇所における電極部７１の密度が白鍵２に対応する箇所における電極部７１の密度よりも大きいので、黒鍵３に対応する箇所の電気抵抗値を白鍵に対応する箇所の電気抵抗値よりも小さくすることができる。
【００５３】
このため、白鍵２と黒鍵３との各前端部２ａ、３ａを同程度の力Ｆ０で押鍵した際、白鍵２と黒鍵３との各押鍵位置２ａ、３ａまでの長さＳ１、Ｓ２の違いにより白鍵２と黒鍵３とでモーメントが異なり、これにより黒鍵３に対応する箇所のセンサシート１８に加わる押圧力Ｆ２が白鍵２に対応する箇所のセンサシート１８に加わる押圧力Ｆ１よりも小さくても、黒鍵３に対応する箇所の電気抵抗値を白鍵３に対応する箇所の電気抵抗値よりも小さくすることができ、これにより黒鍵３と白鍵２とによる押圧力Ｆ２、Ｆ１に差が生じても、白鍵２と黒鍵３とに対応する箇所における電極部７１の密度、および黒鍵３に対応する箇所のセンサシート１８のスリット７６の間隔を適宜設定して、白鍵２と黒鍵３とに対応する箇所の電気抵抗値を調節することにより、感圧層２０による電極部７１の導通状態を同程度にすることができる。この結果、第１実施形態と同様、感圧センサ７５が同程度の電気抵抗値を出力し、この電気抵抗値に基づいて白鍵２および黒鍵３と共に発音中の音に各種の効果を同程度付与して放音することができ、良好に楽音を放音させることができる。
【００５４】
なお、上記第１〜第１０実施形態では、感圧センサの基板１５の上面に櫛歯状の電極部１６を形成し、これに対向するセンサシート１８の下面に感圧層２０を設けた構成の感圧センサについて述べたが、これに限らず、例えば、図３６（ａ）および図３６（ｂ）に示すように、基板１５上に一方（下側）の電極１６ａを形成し、この下側の電極１６ａ上に感圧層２０を形成し、これに対向するセンサシート１８の下面に他方（上側）の電極１６ｂを形成し、この上側の電極１６ｂを感圧層２０に離間対向させた構成の感圧センサであっても良い。この場合、電極１６ａ、１６ｂは、単純な平板状に形成しても良く、また櫛歯状に形成しても良い。
このような感圧センサでは、センサシート１８上のフェルト１９が鍵２、３のセンサ押圧部６により押圧されると、センサシート１８が撓んで、その下面の上側の電極１６ｂが感圧層２０に接触することにより、この感圧層２０を介して上下の電極１６ａ、１６ｂが導通する。このような感圧センサを用いても、第１〜第１０実施形態と同様の作用効果がある。
また、この発明は、上記第１〜第１０実施形態およびその各変形例を用途に応じて適宜組み合わせて用いても良いことは言うまでもない。
【００５５】
【発明の効果】
以上説明したように、この発明によれば、白鍵と黒鍵との各前端部を同程度の力で押鍵した際、白鍵と黒鍵との長さの違いにより白鍵と黒鍵とでモーメントが異なり、これにより白鍵に対応する箇所の可撓性部材に加わる押圧力と、黒鍵に対応する箇所の可撓性部材に加わる押圧力とが異なるが、黒鍵に対応する箇所のスペーサの開口領域を白鍵に対応する箇所のスペーサの開口領域よりも広く形成したので、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所の可撓性部材を白鍵に対応する箇所の可撓性部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。
【００５６】
また、白鍵に対応する箇所の可撓性部材の厚みを黒鍵に対応する箇所の可撓性部材の厚みよりも厚く形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所の可撓性部材を白鍵に対応する箇所の可撓性部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。さらに、黒鍵に対応する箇所の周辺に位置する可撓性部材に、スリットを形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所の周辺に位置する可撓性部材のスリットにより、黒鍵に対応する箇所の可撓性部材を白鍵に対応する箇所の可撓性部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。また、黒鍵に対応する箇所における電極とこれに離間対向する感圧層との間隔を、白鍵に対応する箇所における電極とこれに離間対向する感圧層との間隔よりも、狭く形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所における感圧層の一対の電極に対する接触面積および接触圧力を、白鍵に対応する箇所における感圧層の一対の電極に対する接触面積および接触圧力よりも、大きくすることができ、これにより同程度の検出信号を得ることができる。さらに、スペーサを弾性材料で形成し、黒鍵に対応する箇所のスペーサの弾性係数を白鍵に対応する箇所のスペーサの弾性係数よりも小さく形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対する箇所のスペーサを白鍵に対する箇所のスペーサよりも大きく弾性変形させることができ、これにより同程度の検出信号を得ることができる。
【００５７】
また、可撓性部材と緩衝部材との間に設けられ、白鍵と黒鍵との各前端部を同程度の力で押鍵して感圧層により一対の電極を導通させる際、白鍵と黒鍵とに対応する箇所の導通状態を同程度に規制する規制部材を有し、この規制部材が、鍵に対応する箇所に開口部が形成され、これら開口部のうち、黒鍵に対応する箇所の開口部が鍵に対応する箇所の開口部よりも広く形成された構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、規制部材の開口部の大きさの違いにより、黒鍵に対応する箇所の可撓性部材を白鍵に対応する箇所の可撓性部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。
【００５８】
また、規制部材が、可撓性を有する材料からなり、白鍵に対応する箇所の厚みが黒鍵に対応する箇所の厚みよりも厚く形成された構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所の規制部材を白鍵に対応する箇所の規制部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。また、規制部材が、可撓性を有する材料からなり、黒鍵に対応する箇所の周辺位置にスリットが形成された構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の規制部材に加わる押圧力が白鍵に対応する箇所の規制部材に加わる押圧力よりも小さくても、スリットにより黒鍵に対応する箇所の規制部材を白鍵に対応する箇所の規制部材よりも大きく撓ませることができ、これにより同程度の検出信号を得ることができる。
【００５９】
さらに、一対の電極が、それぞれ櫛歯状をなし、基板上に互いに接触することなく噛み合った状態で形成され、感圧層が可撓性部材の下面に一対の電極に対し離間対向して設けられ、調整手段が、黒鍵に対応する箇所における一対の電極の噛み合い密度を白鍵に対応する箇所における一対の電極の噛み合い密度よりも大きく形成した構成であれば、白鍵と黒鍵とのモーメントの差により、黒鍵に対応する箇所の可撓性部材に加わる押圧力が白鍵に対応する箇所の可撓性部材に加わる押圧力よりも小さくても、黒鍵に対応する箇所における感圧層の一対の電極に対する導通密度を、白鍵に対応する箇所における感圧層の一対の電極に対する導通密度よりも、大きくすることができ、これにより同程度の検出信号を得ることができる。
【図面の簡単な説明】
【図１】この発明の感圧センサの第１実施形態におけるスペーサおよび電極部を示した要部平面図。
【図２】図１の各矢視における感圧センサの各断面を示し、（ａ）は図１のＸ１−Ｘ１矢視における拡大断面図、（ｂ）は図１のＸ２−Ｘ２矢視における拡大断面図。
【図３】図２のセンサシートの撓みの原理を説明するための図。
【図４】図２の感圧センサにおける押圧力に対する電気抵抗値の特性を示した図。
【図５】第１実施形態の感圧センサの各変形例を示し、（ａ）は第１変形例の感圧センサにおけるスペーサおよび電極部を示した要部平面図、（ｂ）は第２変形例の感圧センサにおけるスペーサおよび電極部を示した要部平面図。
【図６】この発明の感圧センサの第２実施形態におけるスペーサおよび電極部を示した要部平面図。
【図７】図６のＸ３−Ｘ３矢視における感圧センサの拡大断面図。
【図８】図６の各矢視における感圧センサの各断面を示し、（ａ）は図６のＸ４−Ｘ４矢視における拡大断面図、（ｂ）は図６のＸ５−Ｘ５矢視における拡大断面図。
【図９】この発明の感圧センサの第３実施形態におけるセンサシートを示した要部平面図。
【図１０】図９のＸ６−Ｘ６矢視における感圧センサの拡大断面図。
【図１１】図９のＸ７−Ｘ７矢視における感圧センサの拡大断面図。
【図１２】第２実施形態の変形例を示した感圧センサの要部の拡大断面図。
【図１３】この発明の感圧センサの第４実施形態におけるスペーサおよび電極部を示した要部平面図。
【図１４】図１３のＸ８−Ｘ８矢視における感圧センサの拡大断面図。
【図１５】図１３の規制部材を示した要部平面図。
【図１６】第４実施形態の変形例を示した規制部材を示した要部平面図。
【図１７】この発明の感圧センサの第５実施形態における規制部材を示した要部平面図。
【図１８】図１７のＸ９−Ｘ９矢視における感圧センサの拡大断面図。
【図１９】図１７の各矢視における感圧センサの各断面を示し、（ａ）は図１７のＸ１０−Ｘ１０矢視における拡大断面図、（ｂ）は図１７のＸ１１−Ｘ１１矢視における拡大断面図。
【図２０】この発明の感圧センサの第６実施形態における規制部材を示した要部平面図。
【図２１】図２０のＸ１２−Ｘ１２矢視における感圧センサの拡大断面図。
【図２２】図２０の各矢視における感圧センサの各断面を示し、（ａ）は図２０のＸ１３−Ｘ１３矢視における拡大断面図、（ｂ）は図２０のＸ１４−Ｘ１４矢視における拡大断面図。
【図２３】規制部材の変形例を示した要部平面図。
【図２４】この発明の感圧センサの第７実施形態におけるスペーサを示した要部平面図。
【図２５】図２４の各矢視における感圧センサの各断面を示し、（ａ）は図２４のＸ１５−Ｘ１５矢視における拡大断面図、（ｂ）は図２４のＸ１６−Ｘ１６矢視における拡大断面図。
【図２６】この発明の感圧センサの第８実施形態におけるスペーサおよび電極部を示した要部平面図。
【図２７】図２６のＸ１７−Ｘ１７矢視における感圧センサの拡大断面図。
【図２８】図２６の各矢視における感圧センサの各断面を示し、（ａ）は図２６のＸ１８−Ｘ１８矢視における拡大断面図、（ｂ）は図２６のＸ１９−Ｘ１９矢視における拡大断面図。
【図２９】第８実施形態の感圧センサにおける押圧力に対する電気抵抗値の特性を示した図。
【図３０】この発明の感圧センサの第９実施形態におけるスペーサおよび電極部を示した要部平面図。
【図３１】図３０のＸ２０−Ｘ２０矢視における感圧センサの拡大断面図。
【図３２】図３０のＸ２１−Ｘ２１矢視において、感圧センサが押圧された動作状態を示した拡大断面図
【図３３】第９実施形態図の感圧センサにおける押圧力に対する電気抵抗値の特性を示した図。
【図３４】この発明の感圧センサの第１０実施形態におけるセンサシートを示した要部平面図。
【図３５】図３５のＸ２２−Ｘ２２矢視における感圧センサの拡大断面図。
【図３６】この発明の感圧センサの他の基本構成を示し、（ａ）はその拡大断面図、（ｂ）はそのＸ２３−Ｘ２３矢視における拡大平面図。
【図３７】従来の感圧センサを用いた電子鍵盤楽器の断面図。
【図３８】図３７の要部平面図。
【図３９】図３７の鍵の押鍵状態を示し、（ａ）は白鍵を押鍵した状態を示した断面図、（ｂ）は黒鍵を押鍵した状態を示した断面図。
【図４０】従来の感圧センサを示し、（ａ）はその拡大断面図、（ｂ）はそのＸ２４−Ｘ２４矢視における拡大平面図。
【図４１】図４０の感圧センサが押圧された動作状態を示した拡大断面図。
【図４２】図４０および図４１の感圧センサにおける押圧力に対する電気抵抗値の基本的な特性を示した図。
【図４３】図３７の電子鍵盤楽器の回路構成を示したブロック図。
【図４４】図４３の電子鍵盤楽器において白鍵と黒鍵とによる感圧センサの押圧力に対する電気抵抗値の特性を示した図。
【符号の説明】
１ 鍵盤シャーシ
２ 白鍵
３ 黒鍵
15 基板
16、71 電極部
16a、16b、71a、71b 一対の電極
17、31、36、61 スペーサ
18、41 センサシート
19 フェルト
20 感圧層
30、35、40、45、50、55、60、65、70、75 感圧センサ
46、48、51、56、58 規制部材
57 開口部
59、76 スリット
Ｌ１ 白鍵に対応する箇所のスペーサの間隔
Ｌ２ 黒鍵に対応する箇所のスペーサの間隔
ｈ１ 白鍵に対応する箇所のセンサシートの厚み
ｈ２ 黒鍵に対応する箇所のセンサシートの厚み
ｈ３ 白鍵に対応する箇所の規制部材の厚み
ｈ４ 黒鍵に対応する箇所の規制部材の厚み
Ｈ１ 白鍵に対応する箇所の電極部と感圧層との間隔
Ｈ２ 黒鍵に対応する箇所の電極部と感圧層との間隔[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure sensor used in an electronic keyboard instrument such as an electronic piano.
[0002]
[Prior art]
Conventionally, in an electronic keyboard instrument such as an electronic piano, after normal key pressing, the pitch, tone, volume, etc. are changed according to the force of pressing the key, giving various effects to the sound being pronounced, Some have an aftertouch function that enhances the expressiveness of sound.
FIG. 37 to FIG. 44 are diagrams showing an example thereof. As shown in FIGS. 37 and 38, the electronic keyboard instrument includes a keyboard chassis 1 incorporated in a musical instrument case, and a plurality of whites made of synthetic resin mounted on the keyboard chassis 1 so as to be rotatable in the vertical direction. A key 2 and a plurality of black keys 3; a rubber switch 5 which is arranged corresponding to each of the plurality of keys 2 and 3 and is pressed by the switch pressing portion 4 of each key 2 and 3 when the key is pressed; Further, there is provided a pressure sensor 7 for after-touch that is pressed by the sensor pressing portion 6 of each key 2, 3 to detect the key pressing force of each key 2, 3 when the key 2, 3 is pressed. ing.
[0003]
Among the plurality of keys 2 and 3, the white key 2 is vertically moved by a support shaft 9 common to each key on a key support portion 8 provided on the rear end portion of the keyboard chassis 1 at the rear portion (right side portion in FIG. 37). It is attached so as to be rotatable in the direction. The white key 2 is urged upward by a coil spring 10 disposed between the white key 2 and the keyboard chassis 1 in the vicinity of the front side of the key support portion 8 (near the left side in FIG. 37). In this state, the L-shaped stopper piece 11 provided on the front side (left side in FIG. 37) of the white key 2 has an upper limit such as felt provided on the lower surface of the keyboard chassis 1 through the fool hole 1a of the keyboard chassis 1. Abutting against the stopper 12, the position of the white key 2 is regulated to a predetermined upper limit position (initial position). Further, the white key 2 is prevented from being shaken by a key guide portion 13 provided on the keyboard chassis 1 located in the vicinity of the upper limit stopper 12. As shown in FIG. 39 (b), the black key 3 has a shorter overall length than the white key 2 and a height higher than that of the white key 2. Otherwise, the white key 2 And provided on the keyboard chassis 1. In this case, since the lengths of the white key 2 and the black key 3 are different, the white key 2 and the black key 3 have different moments at the tip portions (the left end portion in FIG. 37).
[0004]
Further, as shown in FIG. 37, the rubber switch 5 includes two sets of elastically deformable bulging rubber portions 5a corresponding to the keys 2 and 3, respectively, and these bulging rubber portions 5a are provided in the middle of the keyboard chassis 1. The bulging rubber portions 5a protrude upward through the opening 1b of the keyboard chassis 1 in this state. That is, the rubber switch 5 is provided with movable contacts in the bulging rubber portions 5a, and fixed contacts are provided on the circuit board 14 corresponding to the movable contacts so as to be spaced apart from each other. When the 5a is pressed by the two switch pressing portions 4 formed on the inner surfaces of the keys 2 and 3, the bulging rubber portions 5a are elastically deformed, and the movable contacts come into contact with the fixed contacts with a time difference. As a result, a switch signal corresponding to the depressed keys 2 and 3 is output.
[0005]
The pressure sensor 7 for after-touch is configured such that after the rubber switch 5 is pressed by the switch pressing portions 4 of the pressed keys 2 and 3, and when the keys 2 and 3 are further pressed, 3, the pressing force of each key 2, 3 (force for pressing the pressure-sensitive sensor 7) is detected by being pressed by a standing plate-shaped sensor pressing portion 6 provided on the upper limit stopper piece 11. On the keyboard chassis 1 located near the rear side (near the right side in the figure), that is, away from the support shaft 9 of the key support part 8 toward the front side (left side in the figure) of the keys 2 and 3 by a predetermined distance S0. It is provided at a position along the arrangement direction of the keys 2 and 3. As shown in FIG. 40A, the pressure-sensitive sensor 7 is provided with an electrode portion 16 on a substrate 15, and spacers 17 are provided on the substrate 15 located on both sides of the electrode portion 16. A flexible sensor sheet (flexible member) 18 is disposed on the substrate 15 so as to face and separate from the substrate 15, and a felt (buffer member) 19 is disposed on the sensor sheet 18. Is formed. In this case, as shown in FIG. 40 (b), the electrode portion 16 is composed of a pair of comb-like electrodes 16a and 16b, and the pair of electrodes 16a and 16b are engaged with each other so as not to contact each other. 15 is formed. In addition, a pressure sensitive layer 20 is provided on the lower surface of the sensor sheet 18 facing the electrode sheet 16 so as to be spaced apart from the electrode portion 16. The spacer 17 regulates the gap between the electrode portion 16 and the sensor sheet 18 and bonds the electrode portion 16 and the sensor sheet 18 together. The felt 19 also functions as a lower limit stopper for the keys 2 and 3.
[0006]
In the pressure sensor 7, when the sensor sheet 18 is pressed through the felt 19 by the sensor pressing portions 6 of the keys 2 and 3, the sensor sheet 18 is bent according to the pressing force as shown in FIG. The pressure-sensitive layer 20 on the lower surface contacts the electrode portion 16 to conduct the pair of electrodes 16a and 16b, and the electric resistance value between the pair of electrodes 16a and 16b according to the contact area and the magnitude of the contact pressure at this time Changes, and a detection signal corresponding to the electrical resistance value is output, whereby the pressing force of the keys 2 and 3, that is, the pressing force against the pressure sensor 7 is detected. That is, as shown in FIG. 42, the basic characteristics of the pressure-sensitive sensor 7 are that the contact area and the contact pressure with which the pressure-sensitive layer 20 comes into contact with the electrode portion 16 as the pressing force by the keys 2 and 3 decreases. Since the electrical resistance value is increased and the pressing force by the keys 2 and 3 is increased, the contact area and the contact pressure at which the pressure-sensitive layer 20 is in contact with the electrode portion 16 are increased. Accordingly, a hyperbola is drawn in which the electrical resistance value with respect to the pressing force of the keys 2 and 3 is inversely proportional.
[0007]
The circuit configuration of such an electronic keyboard instrument will be described with reference to FIG.
A CPU 21 which is a central processing unit of the microcomputer controls the entire electronic keyboard instrument system according to a program stored in the ROM 22. The CPU 21 performs scanning at a constant cycle, and takes in a switch signal corresponding to the key depression operation from the rubber switch 5 as pitch data. The pressure-sensitive sensor 7 detects the pressing force of the pressed keys 2 and 3 as an electric resistance value by scanning with a constant cycle by the CPU 21. This electric resistance value is converted into a voltage signal by the resistance voltage converter 23, and then converted into a digital signal by the A / D converter 24, and taken into the CPU 21 as a musical tone control signal. The CPU 21 gives a tone generation command to the sound source unit 25 based on the key pressing operation, and controls a tone signal having a pitch corresponding to the key pressing operation based on the tone control signal, and thereby various effects such as tone color and volume. Is granted. The sound source unit 25 generates a tone signal to which various effects are given based on the tone control signal. This musical sound signal is converted into an analog signal by the D / A converter 26, amplified by the amplifier 27, and emitted as a musical sound from the speaker 28.
[0008]
In such an electronic keyboard instrument, as shown in FIG. 37, the keys 2 and 3 are pushed up by the coil springs 10, and the stopper pieces 11 of the keys 2 and 3 come into contact with the upper limit stopper 12 of the keyboard chassis 1, When, for example, the white key 2 of the keys 2 and 3 is pressed against the spring force of the coil spring 10 in a state where the keys 2 and 3 are regulated to the initial position (upper limit position). 39 (a), the white key 2 rotates downward about the support shaft 9 of the key support portion 8, and the switch pressing portion 4 of the white key 2 corresponds to each bulging rubber of the rubber switch 5. By sequentially elastically deforming the part 5a and bringing each movable contact into contact with each fixed contact, the rubber switch 5 outputs a switch signal having a pitch corresponding to the pressed white key 2, and starts to emit a musical tone To do. Thereafter, when the white key 2 is further pressed, the pressure-sensitive sensor 7 is pressed by the sensor pressing portion 6 of the white key 2, and the pressure-sensitive layer 20 comes into contact with the electrode portion 16 as shown in FIG. At this time, the pressure-sensitive layer 20 makes the pair of electrodes 16a and 16b conductive with a contact area and a contact pressure corresponding to the pressing force against the pressure sensor 7 (the pressing force of the white key 2). Thereby, the pressure-sensitive sensor 7 outputs an electric resistance value corresponding to the conduction state as a detection signal, and the detection signal corresponding to the electric resistance value is taken into the CPU 21 as a musical sound control signal. The CPU 21 changes the timbre, volume, and the like based on the detection signal, applies various effects to the sound being generated, and emits the sound, thereby enhancing the expressiveness of the sound. The black key 3 operates in the same manner as the white key 2.
[0009]
[Problems to be solved by the invention]
However, in such an electronic keyboard instrument, as shown in FIGS. 39 (a) and 39 (b), the pressure-sensitive sensor 7 is on the keyboard chassis 1 separated from the support shaft 9 of the key support portion 8 by a predetermined distance S0. In this state, when the keys 2 and 3 are pressed and the sensor pressing portion 6 presses the pressure sensor 7, the front end portions 2a and 3a of the white key 2 and the black key 3 are When the key is pressed with the same force F0, the length S1 from the support shaft 9 to the key pressing position 2a of the white key 2 is longer than the length S2 to the key pressing position 3a of the black key 3 (S1> S2). The moments differ depending on the lengths S1 and S2 of the keys 2 and 3 up to the key pressing positions 2a and 3a. For this reason, a difference occurs in the pressing forces (pressing forces) F1 and F2 applied to the pressure sensor 7 between the white key 2 and the black key 3, and the pressing force F2 of the black key 3 is smaller than the pressing force F1 of the white key 2. (F2 <F1), and even if the white key 2 and the black key 3 are pressed with the same force, the electric resistance value detected by the pressure sensor 7 differs between the white key 2 and the black key 3. There's a problem.
[0010]
That is, in this pressure-sensitive sensor 7, the portions corresponding to the white key 2 and the black key 3 have exactly the same configuration. Therefore, when the white key 2 and the black key 3 have different moments, as shown in FIG. The detection characteristic of the pressure sensor 7 in the white key 2 (curve W1 shown by a solid line in the figure) and the detection characteristic of the pressure sensor 7 in the black key 3 (curve B1 shown by a two-dot chain line in the figure) overlap. In addition, the detection characteristic (curve W1) of the pressure sensor 7 in the white key 2 and the detection characteristic (curve B1) of the pressure sensor 7 in the black key 3 are shifted by a difference in pressing force (F1-F2). This causes a difference in electrical resistance value. For this reason, even if the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the detection signals from the pressure sensor 7 are different between the white key 2 and the black key 3, and the sound is being generated. There is a difference in the effect given to the sound, and there is a problem that the musical sound cannot be emitted well.
[0011]
An object of the present invention is to obtain the same detection signal even when the pressing force varies depending on the moment difference between the white key and the black key.
[0012]
[Means for Solving the Problems]
  The present invention provides a keyboard chassis in which a plurality of keys having different lengths of a white key and a black key are arranged so as to be pivotable in the vertical direction about a fulcrum at the same position, and the key is located at a fixed distance from the fulcrum. A pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,A substrate provided under each of the keys; a flexible member provided on the substrate in a state of being opposed to and spaced apart from each other by a spacer; A pair of electrodes provided in a region facing the flexible member without contacting each other, and at least one of the pair of electrodes are spaced apart from each other, and when the key is depressed, A pressure-sensitive layer for conducting a pair of electrodes, and an opening area of the spacer at a position corresponding to the black key is formed wider than an opening area of the spacer at a position corresponding to the white keyIt is characterized by that. According to this invention, when each front end of the white key and the black key is pressed with the same level of force, the white key and the black key have different moments due to the difference in length between the white key and the black key. Thereby, the pressing force applied to the flexible member at the location corresponding to the white key is different from the pressing force applied to the flexible member at the location corresponding to the black key.If the opening area of the spacer corresponding to the black key is wider than the opening area of the spacer corresponding to the white key, it corresponds to the black key due to the moment difference between the white key and the black key. Even if the pressing force applied to the flexible member at the location is smaller than the pressing force applied to the flexible member at the location corresponding to the white key, the location at which the flexible member at the location corresponding to the black key corresponds to the white key The flexible member can be deflected to a greater extent than the other flexible member, thereby obtaining the same level of detection signal.
[0013]
  Moreover, as described in claim 2,If the thickness of the flexible member at the location corresponding to the white key is thicker than the thickness of the flexible member at the location corresponding to the black key, the thickness of the black Even if the pressing force applied to the flexible member at the position corresponding to the key is smaller than the pressing force applied to the flexible member at the position corresponding to the white key, the flexible member at the position corresponding to the black key is the white key. Can be bent larger than the flexible member at a location corresponding to the above, and thus a detection signal of the same level can be obtained.
[0014]
  Moreover, as described in claim 3,If the flexible member located around the location corresponding to the black key has a slit, the flexible member located at the location corresponding to the black key will be affected by the difference in moment between the white key and the black key. Even if the pressing force applied is smaller than the pressing force applied to the flexible member at the location corresponding to the white key, the location corresponding to the black key is due to the slit of the flexible member located around the location corresponding to the black key. The flexible member can be bent more greatly than the flexible member at the portion corresponding to the white key, and thus a detection signal of the same level can be obtained.Further, as described in claim 4, if the spacer is formed of an elastic material, the elastic coefficient of the spacer corresponding to the black key is smaller than the elastic coefficient of the spacer corresponding to the white key. Depending on the moment difference between the white key and the black key, even if the pressing force applied to the flexible member at the location corresponding to the black key is smaller than the pressing force applied to the flexible member at the location corresponding to the white key, The spacer for the black key can be more elastically deformed than the spacer for the white key, thereby obtaining the same level of detection signal. Furthermore, as described in claim 5, the distance between the electrode at the location corresponding to the black key and the pressure-sensitive layer facing away from the electrode is separated from the electrode at the location corresponding to the white key and the pressure-sensitive layer facing away from this. If the configuration is formed narrower than the distance between the two, the pressing force applied to the flexible member at the location corresponding to the black key is caused by the difference in the moment between the white key and the black key. The contact area and the contact pressure of the pressure-sensitive layer with respect to the pair of electrodes in the portion corresponding to the black key, even if the pressure force is smaller than the pressing force applied to the conductive member, The area and the contact pressure can be made larger, whereby a detection signal of the same level can be obtained.
[0015]
  Further, as described in claim 6, the present invention provides a keyboard chassis on which a plurality of keys having different lengths of white and black keys are arranged so as to be pivotable in the vertical direction around a fulcrum at the same position. A pressure-sensitive sensor arranged along a key arrangement direction at a certain distance from a fulcrum and detecting the key pressing force of the key when the key is pressed, provided at the lower part of each key Provided on the substrate, a pair of electrodes provided on the substrate, and a spacer having an opening on the substrate, and provided at a position opposed to the pair of electrodes. A flexible member that bends downward when pressed by the pressure member, a buffer member that is provided on the upper surface of the flexible member and absorbs an impact from the key when the key is depressed, and a lower surface of the flexible member. Provided, and when the key is depressed, the flexible member is brought into contact with the pair of electrodes by bending of the flexible member. The pressure-sensitive layer that conducts the pair of electrodes to each other, and is provided between the flexible member and the buffer member, and the degree of bending of the flexible member when the key is pressed is determined by A restricting member for restricting the black key to be larger than when the key is pressed, and the restricting member has an opening formed at a position corresponding to the key. Of the opening, the opening corresponding to the black key is formed wider than the opening corresponding to the white key.
   According to this invention,The restriction member may have a configuration in which an opening is formed at a position corresponding to the key, and an opening at a position corresponding to the black key is wider than an opening at a position corresponding to the white key. For example, due to the moment difference between the white key and the black key, even if the pressing force applied to the flexible member at the location corresponding to the black key is smaller than the pressing force applied to the flexible member at the location corresponding to the white key. Due to the difference in the size of the opening of the restricting member, the flexible member at the location corresponding to the black key can be deflected to a greater extent than the flexible member at the location corresponding to the white key. A detection signal can be obtained. Claims7If the restriction member is made of a flexible material and the thickness of the portion corresponding to the white key is thicker than the thickness of the portion corresponding to the black key, the white key and black Even if the pressing force applied to the flexible member at the location corresponding to the black key is smaller than the pressing force applied to the flexible member at the location corresponding to the white key due to the difference in moment from the key, it corresponds to the black key. The restricting member at the location can be bent more greatly than the restricting member at the location corresponding to the white key, whereby a detection signal of the same level can be obtained.
[0016]
  Furthermore, as described in claim 8,If the restricting member is made of a flexible material and has a slit formed in the peripheral position of the portion corresponding to the black key, it corresponds to the black key due to the moment difference between the white key and the black key. Even if the pressing force applied to the regulating member at the location is smaller than the pressing force applied to the regulating member at the location corresponding to the white key, the regulating member at the location corresponding to the black key by the slit is more than the regulating member at the location corresponding to the white key. Can be greatly bent, and a detection signal of the same level can be obtained. If the restricting member is made of a flexible material and has a slit formed in the peripheral position of the portion corresponding to the black key, it corresponds to the black key due to the moment difference between the white key and the black key. Even if the pressing force applied to the regulating member at the location is smaller than the pressing force applied to the regulating member at the location corresponding to the white key, the regulating member at the location corresponding to the black key by the slit is more than the regulating member at the location corresponding to the white key. Can be greatly bent, and a detection signal of the same level can be obtained.
[0017]
  Furthermore, as described in claim 9, the present invention provides a keyboard chassis in which a plurality of keys having different lengths of white and black keys are arranged so as to be pivotable up and down around a fulcrum at the same position. A pressure-sensitive sensor arranged along a key arrangement direction at a certain distance from a fulcrum and detecting the key pressing force of the key when the key is pressed, provided at the lower part of each key And a flexible member that is provided on the substrate in a state of being opposed to and spaced from each other via a spacer, and that is bent by being pressed by the key when the key is pressed, and an opposing region between the substrate and the flexible member A pair of electrodes provided without contacting each other, and at least one of the pair of electrodes are spaced apart from each other, and the pair of electrodes are electrically connected by bending of the flexible member when the key is pressed. Each of the pair of electrodes is a comb tooth. The pressure sensitive layer is formed on the lower surface of the flexible member so as to be opposed to the pair of electrodes, and is formed on the black key. The mesh density of the pair of electrodes at the corresponding location is formed larger than the mesh density of the pair of electrodes at the location corresponding to the white key.
  According to this invention,Each of the pair of electrodes has a comb-like shape and is formed in a state of being engaged with each other without contacting each other on the substrate, and a pressure-sensitive layer is provided on the lower surface of the flexible member so as to be opposed to the pair of electrodes, If the adjusting means has a configuration in which the engagement density of the pair of electrodes at the location corresponding to the black key is larger than the engagement density of the pair of electrodes at the location corresponding to the white key, the moment of the white key and the black key Due to the difference, even if the pressing force applied to the flexible member at the location corresponding to the black key is smaller than the pressing force applied to the flexible member at the location corresponding to the white key, the pressure-sensitive layer at the location corresponding to the black key The conduction density with respect to the pair of electrodes can be made larger than the conduction density with respect to the pair of electrodes of the pressure-sensitive layer in the portion corresponding to the white key, and thus a detection signal of the same level can be obtained.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
A first embodiment of a pressure sensitive sensor according to the present invention will be described below with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same part as the prior art example shown by FIGS. 37-44, and the description is abbreviate | omitted.
The pressure sensor 30 has the same configuration as that of the conventional example except that the opening area of the spacer 31 is different at locations corresponding to the white key 2 and the black key 3.
That is, as shown in FIGS. 1 and 2, the spacer 31 is provided on both sides of the substrate 15 along the arrangement direction of the keys 2, 3, and the arrangement of the keys 2, 3 at a location corresponding to the black key 3. Cutout portions 32 are respectively provided in opposing portions in a direction orthogonal to the direction. Accordingly, the spacer 31 has a spacer L2 at a position corresponding to the black key 3 in a space perpendicular to the arrangement direction of the keys 2 and 3, and a spacer L2 at a position corresponding to the white key 2. The two cutouts 32 on both sides are wider (L2> L1) than the interval L1 of 31. Thus, the spacer 31 is formed so that the opening area corresponding to the black key 3 is wider than the opening area of the spacer 31 corresponding to the white key 2.
[0019]
In such a pressure-sensitive sensor 30, the distance L2 between the spacers 31 corresponding to the black key 3 is formed wider than the distance L1 between the spacers 31 corresponding to the white key 2. When the felt 19 that is a buffer member is pressed with the same force by the sensor pressing portion 6, the sensor sheet 18 that is a flexible member corresponding to the black key 3 is replaced with the sensor sheet 18 that corresponds to the white key 2. Will bend to a greater extent.
As shown in FIG. 3, the sensor sheet 18 forms a fixed beam, both ends thereof are fixed on the spacer 31, and the corresponding sensor sheet 18 between the spacers 31 has a uniform load w (Kg / cm). This is because it corresponds to the deflection ν of the beam when receiving.
[0020]
The general formula for the deflection ν of this beam is
ν = {wx2/ 24EI} (Lx)2  ………… (1)
It is. However, L is the space | interval of the spacer 31, x is the arbitrary positions of the sensor sheet 18 in the space | interval L of the spacer 31, E is an elastic modulus (Young's modulus), and I is a cross-sectional secondary moment. Since this cross-sectional secondary moment I has a rectangular cross-sectional shape,
I = (1/12) bhThree              ………… (2)
It is. However, b is the width of the opening region of the spacer 31 along the arrangement direction of the keys 2 and 3, and h is the thickness of the sensor sheet 18.
Substituting this equation (2) into equation (1),
ν = {wx2/ 2EbhThree} (Lx)2  ………… (3)
It becomes. The maximum deflection νmaxIs the intermediate position (L / 2) of the sensor sheet 18 within the interval L of the spacer 31.
Figure 0003757666
Is established.
As a result, it can be seen from the above equations (3) and (4) that the greater the distance L between the spacers 31, the greater the amount of deflection of the sensor sheet 18.
[0021]
Therefore, in this pressure-sensitive sensor 30, the distance L2 between the spacers 31 corresponding to the black key 3 is wider than the distance L1 between the spacers 31 corresponding to the white key 2 by two notches 32 on both sides (L2>). L1) Since it is formed, the sensor sheet 18 corresponding to the black key 3 bends more than the sensor sheet 18 corresponding to the white key 2. Therefore, in this pressure-sensitive sensor 30, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the key pressing positions of the white key 2 and the black key 3 are pressed. The moments of the white key 2 and the black key 3 differ depending on the lengths S1 and S2 up to 2a and 3a, so that the pressing force F2 applied to the sensor sheet 18 at the location corresponding to the black key 3 corresponds to the white key 2. Even if the pressure F1 is smaller than the pressing force F1 applied to the sensor sheet 18 at the location to be applied (F2 <F1), the sensor sheet 18 at the location corresponding to the black key 3 is bent more than the sensor sheet 18 at the location corresponding to the white key 3. Thus, even if there is a difference in the pressing forces F2 and F1 between the black key 3 and the white key 2, the amount of cut of the two notches 32 of the spacer 31 corresponding to the black key 3 can be adjusted. As a result, the conduction state of the electrode part 16 by the pressure-sensitive layer 20 is approximately the same. It can be.
[0022]
That is, in this pressure-sensitive sensor 30, even if the moments of the white key 2 and the black key 3 are different by adjusting the cut amounts of the two notches 32 of the spacer 31 corresponding to the black key 3, the pressure sensor 30 4, the detection characteristic of the pressure sensor 30 in the white key 2 (curve W2 indicated by a solid line in the figure) and the detection characteristic of the pressure sensor 30 in the black key 3 (curve indicated by a two-dot chain line in the figure) B2) and the same curve coincide with almost the same position. As a result, even if there is a difference in the pressing forces F2 and F1 between the black key 3 and the white key 2, the contact area and the contact pressure at which the pressure-sensitive layer 20 contacts the electrode portion 16 are substantially the same, A resistance value can be obtained. For this reason, even if the front ends 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the conduction state of the pressure-sensitive sensor 30 is the same for the white key 2 and the black key 3. The pressure sensitive sensor 30 can output the same level of electrical resistance, and the white key 2 and the black key 3 together with the white key 2 and the black key 3 give various effects to the sound being generated and emit sound. It is possible to radiate a musical tone satisfactorily.
[0023]
In the first embodiment, the notch 32 is provided in the portion of the portion corresponding to the black key 3 that faces the spacer 31. However, the present invention is not limited to this, and for example, FIG. 5A or FIG. You may comprise like each modification shown in these.
The first modification shown in FIG. 5A is on the front side (left side in the figure) of the keys 2 and 3 among the spacers 31a and 31b on both sides provided along the arrangement direction of the keys 2 and 3. The width of the spacer 31a (the length in the direction orthogonal to the arrangement direction of the keys 2 and 3) is narrowed, and the width of the spacer 31b located behind the keys 2 and 3 (right side in the figure) is wide. In the wide spacer 31b, the notch 32 is formed only in the portion opposite to the portion corresponding to the black key 3, so that the space L2 between the spacers 31a and 31b corresponding to the black key 3 is It is formed wider than the distance L1 between the spacers 31a and 31b at the location corresponding to the key 2, and the opening area of the spacer 31a and 31b at the location corresponding to the black key 3 is the opening of the spacer 31a and 31b at the location corresponding to the white key 2. It is configured to be wider than the area
Further, in the second modified example shown in FIG. 5B, in the first modified example, the notch 32 corresponding to the black key 3 is penetrated in a direction perpendicular to the arrangement direction of the keys 2 and 3. It has a formed configuration.
Needless to say, the first and second modified examples have the same effects as those of the first embodiment.
[0024]
[Second Embodiment]
Next, a second embodiment of the pressure-sensitive sensor according to the present invention will be described with reference to FIGS. Also in this case, the same parts as those in the conventional example shown in FIGS.
The pressure-sensitive sensor 35 has the same configuration as that of the conventional example except that the opening area of the spacer 36 is different at locations corresponding to the white key 2 and the black key 3.
That is, as shown in FIGS. 6 to 8, the spacer 36 is provided on the both sides of the substrate 15 in the same shape along the arrangement direction of the keys 2 and 3, and is opposed to the portions corresponding to the keys 2 and 3. Notch portions 37 and 38 are respectively provided in the portions, and the intervals L of the spacers 36 corresponding to these notch portions 37 and 38 are formed to have the same length.
In this case, the length b2 of the notch 38 corresponding to the black key 3 among the lengths b1 and b2 in the arrangement direction of the keys 2 and 3 in the notches 37 and 38 corresponding to the keys 2 and 3 respectively. Is longer than the length b1 of the notch 37 corresponding to the white key 2 (b2> b1). Thus, the spacer 36 is formed so that the opening area corresponding to the black key 3 is wider than the opening area of the spacer 36 corresponding to the white key 2.
The sensor pressing portions 6 of the keys 2 and 3 are formed in a standing plate shape, and the length m1 in the direction orthogonal to the arrangement direction of the keys 2 and 3 is sufficiently longer than the intervals L of the spacers 36 ( m1> L) and the length m2 in the arrangement direction of the keys 2 and 3 is sufficiently shorter than the length b1 of the notch 37 corresponding to the white key 2 (m2 <b1 <b2). Has been.
[0025]
In such a pressure sensor 35, the length b2 of the notch 38 of the spacer 36 corresponding to the black key 3 is longer than the length b1 of the notch 37 corresponding to the white key 2 (b2> b1). ) So that the opening area of the portion corresponding to the black key 3 is formed wider than the opening area of the spacer 36 corresponding to the white key 2, so that the sensor pressing portion 6 of the keys 2 and 3 cushions it. When the felt 19 that is a member is pressed with the same force, the sensor sheet 18 that is a flexible member corresponding to the black key 3 bends more greatly than the sensor sheet 18 that corresponds to the white key 2. become.
This is because the length m2 in the arrangement direction of the keys 2 and 3 in the sensor pressing portion 6 of each key 2 and 3 is sufficiently shorter than the length b1 of the notch 37 corresponding to the white key 2 ( Since m2 <b1 <b2) is formed, when the felt 19 at the location corresponding to each key 2 and 3 is pressed with the same force by the sensor pressing portion 6, as shown in FIG. Since the length b2 of the notch 38 of the spacer 36 at the corresponding location is longer than the length b1 of the notch 37 at the location corresponding to the white key 2 (b2> b1), the sensor sheet at the location corresponding to the black key 3 This is because 18 extends and bends more greatly in the direction in which the keys 2 and 3 are arranged than the sensor sheet 18 corresponding to the white key 2.
[0026]
For this reason, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the lengths of the white key 2 and the black key 3 up to the key pressing positions 2a and 3a. The moment is different between the white key 2 and the black key 3 due to the difference between S1 and S2, so that the pressing force F2 applied to the sensor sheet 18 at the location corresponding to the black key 3 is applied to the sensor sheet 18 at the location corresponding to the white key 2. Even if it is smaller than the applied pressing force F1, the sensor sheet 18 corresponding to the black key 3 can be bent more greatly than the sensor sheet 18 corresponding to the white key 3, whereby the black key 3 and the white key can be bent. 2, the lengths b1 and b2 of the notches 37 and 38 of the spacers 36 corresponding to the white key 2 and the black key 3 are appropriately set so that the white key 2 By adjusting the width of each opening area corresponding to the black key 3 The conduction state of the electrode portion 16 by 20 may be to the same extent. As a result, as in the first embodiment, the pressure-sensitive sensor 35 outputs an electric resistance value of the same level, and the white key 2 and the black key 3 together with various effects are produced on the sound being generated based on the electric resistance value. The sound can be emitted by giving a degree, and the musical sound can be emitted well.
[0027]
[Third Embodiment]
Next, a third embodiment of the pressure-sensitive sensor according to the present invention will be described with reference to FIGS. Also in this case, the same parts as those in the conventional example shown in FIGS.
The pressure-sensitive sensor 40 has the same configuration as that of the conventional example except that the thickness of the sensor sheet 41 that is a flexible member is different at portions corresponding to the white key 2 and the black key 3. That is, as shown in FIGS. 9 and 10, the sensor sheet 41 is integrally formed with a flat plate portion 42 pressed by the sensor pressing portion 6 of the white key 2 on the upper surface of the portion corresponding to the white key 2. The thickness h1 of the portion corresponding to the white key 2 is formed thicker (h1> h2) than the thickness h2 of the other portion, that is, the portion corresponding to the black key 3. In this case, the flat plate portion 42 is formed such that the length n1 in the direction orthogonal to the arrangement direction of the keys 2 and 3 is longer than the distance L between the spacers 17 in the same direction (n1> L). Both end portions of the flat plate portion 42 in the direction orthogonal to the arrangement direction 3 are positioned on the spacer 17. The flat plate portion 42 has a length n2 in the arrangement direction of the keys 2 and 3 longer than the length m2 of the sensor pressing portion 6 of the keys 2 and 3 in the same direction (n2> m2), and the portion Is formed shorter than the width of the white key 2.
[0028]
In such a pressure-sensitive sensor 40, the thickness h1 of the sensor sheet 41 corresponding to the white key 2 is formed to be thicker (h1> h2) than the thickness h2 of the sensor sheet 41 corresponding to the black key 3. Therefore, when the felt 19 as the buffer member is pressed with the same force by the sensor pressing portions 6 of the keys 2 and 3, the sensor sheet 41 corresponding to the white key 2 corresponds to the sensor sheet 41 corresponding to the black key 3. The amount of bending becomes smaller than that. This is the general formula of the deflection ν and the maximum deflection ν in the first embodiment.maxThe formula of
ν = {wx2/ 2EbhThree} (Lx)2  ………… (3)
νmax= {WLFour/ 32EbhThree} ………… (4)
As is clear from the above, as the thickness h of the sensor sheet 41 increases, the deflection (ν, ν) of the sensor sheet 41 increases.max) Is small.
[0029]
For this reason, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the lengths of the white key 2 and the black key 3 up to the key pressing positions 2a and 3a. The moment is different between the white key 2 and the black key 3 due to the difference between S1 and S2, so that the pressing force F2 applied to the sensor sheet 41 at the location corresponding to the black key 3 is applied to the sensor sheet 41 at the location corresponding to the white key 2. Even if it is smaller than the applied pressing force F1, the sensor sheet 41 corresponding to the black key 3 can be bent more greatly than the sensor sheet 41 corresponding to the white key 3, and thus the black key 3 and the white key can be bent. 2 by appropriately setting the difference (h1−h2) between the thicknesses h1 and h2 of the sensor sheet 41 at locations corresponding to the white key 2 and the black key 3 It is possible to make the conduction state of the electrode part 16 by the pressure-sensitive layer 20 the same level. That. As a result, as in the first embodiment, the pressure-sensitive sensor 40 outputs an electric resistance value of the same level, and the white key 2 and the black key 3 together with various effects are produced based on the electric resistance value. The sound can be emitted by giving a degree, and the musical sound can be emitted well.
[0030]
In the third embodiment, the flat plate portion 42 is formed on the upper surface of the sensor sheet 41 corresponding to the white key 2. However, the present invention is not limited to this. For example, as shown in FIG. A chevron portion 43 is integrally formed on the upper surface of the sensor sheet 41 at a location where the apex corresponds to the sensor pressing portion 6 of the white key 2, and the thickness h1 of the location corresponding to the white key 2 is the other black key. 3 may be formed to be thicker (h1> h2) than the thickness h2 including the portion corresponding to 3. Even if comprised in this way, there exists an effect similar to 3rd Embodiment.
Moreover, in the said 3rd Embodiment and its modification, although the flat plate part 42 or the mountain-shaped part 43 was integrally formed on the sensor sheet 41, it is not necessary to form integrally and you may form separately.
[0031]
[Fourth Embodiment]
Next, a fourth embodiment of the pressure sensor according to the present invention will be described with reference to FIGS. Also in this case, the same parts as those in the conventional example shown in FIGS.
The pressure-sensitive sensor 45 has a configuration in which a regulating member 46 is disposed between the sensor sheet 18 that is a flexible member and the felt 19 that is a buffer member, and the other configuration is the same as that of the conventional example.
That is, as shown in FIGS. 13 to 15, the restricting member 46 is provided on both sides of the sensor sheet 18 so as to substantially correspond to the spacer 17 along the arrangement direction of the keys 2 and 3, and corresponds to the black key 3. The cutout portions 47 are respectively provided at the opposite portions in the direction orthogonal to the arrangement direction of the keys 2 and 3 at the locations. Accordingly, as shown in FIG. 15, the regulating member 46 has an interval L2 between the regulating members 46 at locations corresponding to the black key 3 among the spacings of the regulating members 46 in the direction orthogonal to the arrangement direction of the keys 2 and 3. The two cutout portions 47 on both sides are formed wider (L2> L1) than the interval L1 between the restricting members 46 at locations corresponding to the white key 2. As a result, the restricting member 46 is formed such that the opening area corresponding to the black key 3 is wider than the opening area corresponding to the white key 2, and the lower part of the felt 19 is inserted into each opening area. Has been.
[0032]
In such a pressure-sensitive sensor 45, the distance L2 between the restricting members 46 corresponding to the black key 3 is only two notches 47 on both sides than the distance L1 between the restricting members 46 corresponding to the white key 2. Since the opening area of the restricting member 46 at the location corresponding to the black key 3 is formed wider than the opening area of the restricting member 46 at the location corresponding to the white key 2, When the felt 19 that is a buffer member is pressed with the same force by the two or three sensor pressing portions 6, the sensor sheet 18 corresponding to the black key 3 is more than the sensor sheet 18 corresponding to the white key 2. It will be greatly bent.
This is because the opening area of the restricting member 46 corresponding to the black key 3 is formed wider than the opening area of the restricting member 46 corresponding to the white key 2, and the lower part of the felt 19 is inserted into each opening area. Therefore, when the felt 19 at a location corresponding to each key 2, 3 is pressed with the same force by the sensor pressing portion 6, the felt 19 is regulated by the regulating member 46 and corresponds to the black key 3. The pressing area of the sensor sheet 18 by the felt 19 at the location is larger than the pressing area of the sensor sheet 18 by the felt 19 at the location corresponding to the white key 2, so that the sensor sheet 18 at the location corresponding to the black key 3 is white. This is because it bends larger than the sensor sheet 18 at the location corresponding to the key 2.
[0033]
For this reason, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the lengths of the white key 2 and the black key 3 up to the key pressing positions 2a and 3a. Due to the difference between S1 and S2, the moment is different between the white key 2 and the black key 3, so that the pressing force F2 applied to the felt 19 at the location corresponding to the black key 3 is applied to the felt 19 at the location corresponding to the white key 2. Even if the pressure is smaller than the pressure F <b> 1, the regulating member 46 regulates the felt 19, so that the sensor sheet 18 corresponding to the black key 3 may be bent more than the sensor sheet 18 corresponding to the white key 3. Even if there is a difference in the pressing forces F2 and F1 between the black key 3 and the white key 2, the amount of cut in the notch 47 of the restricting member 46 corresponding to the white key 2 and the black key 3 can be set as appropriate. Then, each of the opening areas corresponding to the white key 2 and the black key 3 By adjusting the of the conducting state of the electrode portion 16 by the pressure sensitive layer 20 it may be to the same extent. As a result, as in the first embodiment, the pressure-sensitive sensor 35 outputs an electric resistance value of the same level, and the white key 2 and the black key 3 together with various effects are produced on the sound being generated based on the electric resistance value. The sound can be emitted by giving a degree, and the musical sound can be emitted well.
[0034]
In the fourth embodiment, the notch 47 is provided in the restriction member 46 at the location corresponding to the black key 3 so that the opening area of the restriction member 46 at the location corresponding to the black key 3 corresponds to the white key 2. Although it is formed wider than the opening region of the restricting member 46 at the location, the present invention is not limited to this. For example, as shown in FIG. 16, the notch portions 48 a and 48 b are respectively provided on the restricting member 48 at the location corresponding to the keys 2 and 3. The distance L between the restricting members 48 corresponding to the notches 48a and 48b is formed to the same length, and the lengths b1 and b2 of the notches 48a and 48b in the arrangement direction of the keys 2 and 3 are set. Of these, the length b2 of the cutout portion 48b corresponding to the black key 3 is formed to be longer (b2> b1) than the length b1 of the cutout portion 48a corresponding to the white key 2, whereby the black key is formed. The opening area of the regulating member 48 at the position corresponding to 3 is white It may be widely formed configuration than the opening area of the regulating member 48 of the portion corresponding to 2. Even if comprised in this way, there exists an effect similar to 4th Embodiment.
[0035]
[Fifth Embodiment]
Next, a fifth embodiment of the pressure-sensitive sensor of the present invention will be described with reference to FIGS. Also in this case, the same parts as those in the conventional example shown in FIGS.
In this pressure-sensitive sensor 50, a restricting member 51 having flexibility is disposed between the sensor sheet 18 that is a flexible member and the felt 19 that is a buffer member, and the thickness of the restricting member 51 is set to the white key 2. The configuration is different in the portion corresponding to the black key 3, and the other configuration is the same as the conventional example.
That is, as shown in FIGS. 17 to 19, the restricting member 51 is formed integrally with the flat plate portion 52 on the upper surface of the sensor sheet 18 corresponding to the white key 2, and thereby the portion corresponding to the white key 2. The thickness h3 is formed to be thicker (h3> h4) than the other portion, that is, the thickness h4 corresponding to the black key 3. In this case, the flat plate portion 52 is formed such that the length n3 in the direction orthogonal to the arrangement direction of the keys 2 and 3 is longer than the distance L between the spacers 17 in the same direction (n3> L). Both end portions of the flat plate portion 52 in the direction orthogonal to the arrangement direction of 3 are positioned on the spacer 17. The flat plate portion 52 is formed such that the length n4 in the arrangement direction of the keys 2 and 3 is longer than the length m2 of the sensor pressing portion 6 of the keys 2 and 3 in the same direction (n4> m2). It is formed shorter than the width of the white key 2 at that location.
[0036]
In such a pressure-sensitive sensor 50, the thickness h3 of the regulating member 51 at the location corresponding to the white key 2 is formed to be thicker (h3> h4) than the thickness h4 of the regulating member 51 at the location corresponding to the black key 3. Therefore, when the felt 19 as the buffer member is pressed with the same force by the sensor pressing portions 6 of the keys 2 and 3, the restriction member 51 corresponding to the white key 2 corresponds to the restriction member 51 corresponding to the black key 3. The amount of bending becomes smaller than that. This is the general formula of the deflection ν and the maximum deflection ν in the first embodiment.maxThe formula of
ν = {wx2/ 2EbhThree} (Lx)2  ………… (3)
νmax= {WLFour/ 32EbhThree} ………… (4)
As is clear from the above, as the thickness h of the sensor sheet 41 increases, the deflection (ν, ν) of the regulating member 51 increases.max) Is small.
[0037]
For this reason, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the lengths of the white key 2 and the black key 3 up to the key pressing positions 2a and 3a. The moment is different between the white key 2 and the black key 3 due to the difference between S1 and S2, so that the pressing force F2 applied to the restriction member 51 at the location corresponding to the black key 3 is applied to the restriction member 51 at the location corresponding to the white key 2. Even if it is smaller than the applied pressing force F1, the regulating member 51 at the location corresponding to the black key 3 will bend more greatly than the regulating member 51 at the location corresponding to the white key 3, whereby the black key 3 and the white key 2, the thicknesses h3 and h4 of the regulating members 51 corresponding to the white key 2 and the black key 3 are appropriately set so that the white key 2 and the black key 3 The electrode portions 16 formed by the pressure-sensitive layer 20 are made to have substantially the same amount of bending of the sensor sheet 18 at a location corresponding to The conduction state can be to the same extent. As a result, as in the first embodiment, the pressure-sensitive sensor 50 outputs an electric resistance value of the same level, and the white key 2 and the black key 3 together with various effects are produced on the sound being generated based on the electric resistance value. The sound can be emitted by giving a degree, and the musical sound can be emitted well.
[0038]
[Sixth Embodiment]
Next, with reference to FIGS. 20-22, 6th Embodiment of the pressure-sensitive sensor of this invention is described. Also in this case, the same parts as those in the conventional example shown in FIGS.
In the pressure sensor 55, a restricting member 56 having flexibility is disposed between the sensor sheet 18 that is a flexible member and the felt 19 that is a buffer member, and a rectangular opening 57 is provided in the restricting member 56. Is formed excluding a part corresponding to the white key 2, and the other configuration is the same as the conventional example.
That is, as shown in FIG. 20 to FIG. 22, the restricting member 56 places the opening 57 into the key 2 at a location excluding the vicinity of the location corresponding to the sensor pressing portion 6 of the white key 2, that is, a location corresponding to at least the black key 3. 3 is formed along the three arrangement directions. In this case, the opening 57 is formed so that the length n5 in the direction orthogonal to the arrangement direction of the keys 2 and 3 is the same length (n5 = L) as the distance L between the spacers 17 in the same direction. The length n6 in the arrangement direction of the keys 2 and 3 is formed to be longer than the width of the black key 3 in the same direction, and the lower part of the felt 19 is inserted into each opening 57 corresponding to these black keys 3. Are arranged.
[0039]
In such a pressure-sensitive sensor 55, an opening 57 is formed in the restricting member 56 corresponding to the black key 3, and the opening 57 is formed in the restricting member 56 near the portion corresponding to the sensor pressing part 6 of the white key 2. When the felt 19 is pressed with the same force by the sensor pressing portions 6 of the keys 2 and 3, the sensor sheet 18 corresponding to the black key 3 is replaced with the sensor sheet corresponding to the white key 2. It will bend more than 18.
This is because the felt 19 directly presses the sensor sheet 18 through the opening 57 of the restricting member 56 at the location corresponding to the black key 3, but the felt 19 presses the restricting member 56 at the location corresponding to the white key 2. Since the regulating member 56 presses the sensor sheet 18 after being bent, the felt 19 in the portion corresponding to each key 2, 3 is pressed with the same force by the sensor pressing portion 6. This is because the sensor sheet 18 at the location to be bent bends more greatly than the sensor sheet 18 at the location corresponding to the white key 2.
[0040]
Therefore, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the lengths of the white key 2 and the black key 3 up to the key pressing positions 2a and 3 are as follows. Due to the difference between S1 and S2, the moment is different between the white key 2 and the black key 3, so that the pressing force F2 applied to the felt 19 at the location corresponding to the black key 3 is applied to the felt 19 at the location corresponding to the white key 2. Even if the pressure is smaller than the pressure F1, the opening 57 of the restricting member 56 restricts the felt 19 so that the sensor sheet 18 corresponding to the black key 3 is larger than the sensor sheet 18 corresponding to the white key 3. Even if there is a difference in the pressing forces F2 and F1 between the black key 3 and the white key 2, the opening of the opening 57 of the restricting member 56 corresponding to the white key 2 and the black key 3 can be bent. Set the amount appropriately and open each opening at the location corresponding to the white key 2 and the black key 3 By adjusting the size of the band, the conduction state of the electrode portion 16 by the pressure sensitive layer 20 it may be to the same extent. As a result, as in the first embodiment, the pressure-sensitive sensor 35 outputs an electric resistance value of the same level, and the white key 2 and the black key 3 together with various effects are produced on the sound being generated based on the electric resistance value. The sound can be emitted by giving a degree, and the musical sound can be emitted well.
[0041]
In the sixth embodiment, the opening 57 is formed in the restricting member 56 at a location excluding the vicinity of the location corresponding to the sensor pressing portion 6 of the white key 2, that is, the location corresponding to the black key 3. However, the present invention is not limited to this. For example, as shown in FIG. 23, a flexible regulation that is located at the peripheral position of the portion corresponding to the black key 3, that is, on both sides of the periphery in the arrangement direction of the keys 2 and 3 in the portion corresponding to the black key 3. The member 58 may have a configuration in which the slits 59 are formed in a direction orthogonal to the arrangement direction of the keys 2 and 3. If comprised in this way, the cross-sectional secondary moment I of the control member 58 of the location corresponding to the black key 3 will be by the slit 59 formed in the control member 58 of the location corresponding to the black key 3.
I = (1/12) bhThree              ………… (2)
Therefore, b (the width of the restricting member 58 along the direction in which the keys 2 and 3 are arranged) in the expression (2) is reduced, and the secondary moment I of the section is thereby reduced. For this reason, according to the expressions (3) and (4) of the first embodiment, the restriction member 58 at the position corresponding to the black key 3 is more easily bent than the restriction member 58 at the position corresponding to the white key 2. There are effects similar to those of the first embodiment.
[0042]
[Seventh Embodiment]
Next, a seventh embodiment of the pressure sensor of the present invention will be described with reference to FIGS. Also in this case, the same parts as those in the conventional example shown in FIGS.
This pressure-sensitive sensor 60 has a configuration in which the spacer 61 is formed of an elastic member, and the elastic coefficient of the spacer 61 is different at locations corresponding to the white key 2 and the black key 3, and the rest is the same as the conventional example. It is configured.
That is, the spacer 61 is made of an elastic material such as rubber, and is provided on both sides of the substrate 15 along the arrangement direction of the keys 2 and 3, and the elastic coefficient of the spacer 61 b at a location corresponding to the black key 3. However, it is configured to be smaller than the elastic coefficient of the spacer 61a at the portion corresponding to the white key 2.
In such a pressure-sensitive sensor 60, when the felt 19 is pressed with the same force by the sensor pressing portions 6 of the keys 2 and 3, the elastic coefficient of the spacer 61 b corresponding to the black key 3 corresponds to the white key 2. Since the elastic coefficient of the spacer 61a is smaller than that of the spacer 61a corresponding to the black key 3, the spacer 61b corresponding to the black key 3 is more contracted and deformed than the spacer 61a corresponding to the white key 2. The sensor sheet 18 is pushed down more than the sensor sheet 18 at the position corresponding to the white key 2.
[0043]
For this reason, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the lengths of the white key 2 and the black key 3 up to the key pressing positions 2a and 3a. Due to the difference between S1 and S2, the moment is different between the white key 2 and the black key 3, so that the pressing force F2 applied to the sensor sheet 18 corresponding to the black key 3 is applied to the sensor sheet 18 corresponding to the white key 2. Even if it is smaller than the applied pressing force F1, the sensor sheet 18 corresponding to the black key 3 can be pushed down more than the sensor sheet 18 corresponding to the white key 3, whereby the black key 3 and the white key 2 can be pressed. Even if there is a difference between the pressing forces F2 and F1 due to the above, the elastic coefficients of the spacers 61a and 61b corresponding to the white key 2 and the black key 3 are appropriately set to correspond to the white key 2 and the black key 3. By adjusting the amount of deformation of the spacers 61a and 61b, The conduction state of the electrode portion 16 by the layer 20 may be to the same extent. As a result, as in the first embodiment, the pressure-sensitive sensor 35 outputs an electric resistance value of the same level, and the white key 2 and the black key 3 together with various effects are produced on the sound being generated based on the electric resistance value. The sound can be emitted by giving a degree, and the musical sound can be emitted well.
In the seventh embodiment, the elastic coefficients of the spacers 61 on both sides are made different at locations corresponding to the white key 2 and the black key 3. However, the present invention is not limited to this, and the white key 2 and the black key 3 are different. The spacers 61 having different elastic coefficients at corresponding locations may be provided only on one side.
[0044]
[Eighth Embodiment]
Next, with reference to FIGS. 26-29, 8th Embodiment of the pressure-sensitive sensor of this invention is described. Also in this case, the same parts as those in the conventional example shown in FIGS.
This pressure-sensitive sensor 65 has a configuration in which the distance between the electrode portion 16 and the pressure-sensitive layer 20 is different at locations corresponding to the white key 2 and the black key 3, and the other configurations are the same as the conventional example. .
That is, as shown in FIGS. 26 to 28, the pressure-sensitive sensor 65 is provided with an insulating plate 66 on the substrate 15 located only at a location corresponding to the black key 3, and passes over the insulating plate 66 to reach the electrode portion. 16 is formed on the substrate 15, whereby the distance H <b> 2 between the electrode portion 16 and the pressure-sensitive layer 20 at the location corresponding to the black key 3 is set to be different from the electrode portion 16 and the pressure-sensitive layer 20 at the location corresponding to the white key 2. The distance H1 is narrower (H1> H2). In this case, the insulating plate 66 is formed to have a thickness greater than that of the electrode portion 16.
[0045]
In such a pressure sensitive sensor 65, the insulating plate 66 provided on the substrate 15 at the location corresponding to the black key 3 allows the distance H2 between the electrode portion 16 and the pressure sensitive layer 20 at the location corresponding to the black key 3. Since the distance H1 between the electrode portion 16 and the pressure-sensitive layer 20 at the portion corresponding to the white key 2 is smaller (H2 <H1), the felt 19 is applied with the same force by the sensor pressing portion 6 of the keys 2 and 3. When the sensor sheet 18 at the location corresponding to the white key 2 and the black key 3 is bent to the same extent, the pressure sensitive layer 20 at the location corresponding to the black key 3 is pressure-sensitive at the location corresponding to the white key 2. The contact area and the contact pressure with respect to the electrode portion 16 are larger than those of the layer 20, whereby the electrical resistance value at the location corresponding to the black key 3 can be made smaller than the electrical resistance value at the location corresponding to the white key.
That is, in this pressure sensor 65, as shown in FIG. 29, the detection characteristic of the pressure sensor 65 in the black key 3 (curve B3 indicated by a two-dot chain line in the same figure) is the same as that of the pressure sensor 65 in the white key 2. Since the detection characteristic (curve W3 indicated by a solid line in the figure) is shifted upward in the middle portion, even if a difference occurs in the pressing forces F2 and F1 between the black key 3 and the white key 2, each curve B3, A similar electrical resistance value can be obtained at the intermediate portion of W3.
[0046]
For this reason, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the lengths of the white key 2 and the black key 3 up to the key pressing positions 2a and 3a. Due to the difference between S1 and S2, the moment is different between the white key 2 and the black key 3, so that the pressing force F2 applied to the sensor sheet 18 corresponding to the black key 3 is applied to the sensor sheet 18 corresponding to the white key 2. Since it becomes smaller than the applied pressing force F1, as shown in FIG. 29, the pressure-sensitive layer 20 can be brought into contact with the electrode portion 16 at the same timing. Moreover, even if the pressing force F2 applied to the sensor sheet 18 at the location corresponding to the black key 3 is smaller than the pressing force F1 applied to the sensor sheet 18 at the location corresponding to the white key 2, the electricity at the location corresponding to the black key 3 can be obtained. The resistance value can be made smaller than the electrical resistance value of the portion corresponding to the white key 3, so that even if there is a difference in the pressing forces F 2 and F 1 between the black key 3 and the white key 2, the white key 2 and the black key By appropriately setting the distances H1 and H2 between the electrode portion 16 and the pressure sensitive layer 20 at the location corresponding to the key 3, and adjusting the electrical resistance value at the location corresponding to the white key 2 and the black key 3, The conduction state of the electrode part 16 by the pressure sensitive layer 20 can be made comparable. As a result, as in the first embodiment, the pressure-sensitive sensor 35 outputs an electric resistance value of the same level, and the white key 2 and the black key 3 together with various effects are produced on the sound being generated based on the electric resistance value. The sound can be emitted by giving a degree, and the musical sound can be emitted well.
[0047]
In the eighth embodiment, the insulating plate 66 is provided on the substrate 15 at the location corresponding to the black key 3, and the electrode portion 16 is formed on the substrate 15 over the insulating plate 66. However, the present invention is not limited to this. For example, the thickness of the pressure-sensitive layer 20 corresponding to the black key 3 is formed thick, and the distance between the pressure-sensitive layer 20 corresponding to the black key 3 and the electrode portion 16 corresponds to the white key 2. It may be formed narrower than the distance between the pressure-sensitive layer 20 and the electrode portion 16 at the location, or the sensor sheet 18 at the location corresponding to the black key 3 is formed thick so that the location corresponding to the black key 3 You may form the space | interval of the pressure sensitive layer 20 and the electrode part 16 narrower than the space | interval of the pressure sensitive layer 20 and the electrode part 16 of the location corresponding to the white key 2. FIG. In this case, the distance between the pressure-sensitive layer 20 and the electrode portion 16 may be increased between the white key 2 and the black key 3 in consideration of the bending of the sensor sheet 18.
[0048]
[Ninth Embodiment]
Next, a ninth embodiment of the pressure sensor according to the present invention will be described with reference to FIGS. Also in this case, the same parts as those in the conventional example shown in FIGS.
This pressure-sensitive sensor 70 has a configuration in which the density of the electrode portion 71 at a location corresponding to the black key 3 is formed larger than the density of the electrode portion 71 at a location corresponding to the white key 2, and the other configurations are the same as the conventional example. It has become.
That is, as shown in FIGS. 30 and 31, the pressure-sensitive sensor 70 is configured so that the distance between the pair of electrodes 71 a and 71 b of the electrode portion 71 located at the location corresponding to the black key 3 is the location corresponding to the white key 2. The distance between the pair of electrodes 71 a and 71 b of the electrode portion 71 located at the center of the electrode portion 71 is narrower, so that the density of the electrode portion 71 in the portion corresponding to the black key 3 is the electrode portion 71 in the portion corresponding to the white key 2. It is formed larger than the density.
[0049]
In such a pressure-sensitive sensor 70, the density of the electrode portion 71 at the location corresponding to the black key 3 is formed larger than the density of the electrode portion 71 at the location corresponding to the white key 2, so that as shown in FIG. When the felt 19 is pressed with the same force by the sensor pressing portions 6 of the keys 2 and 3, and the sensor sheet 18 corresponding to the white key 2 and the black key 3 is bent to the same extent, the white key 2 and the black key 3 Even if the contact area of the pressure-sensitive layer 20 with respect to the electrode portion 71 at the portion corresponding to the black key 3 is the same, due to the difference in the density of the electrode portion 71 between the white key 2 and the black key 3, the portion corresponding to the black key 3 The electrical resistance value can be made smaller than the electrical resistance value at the location corresponding to the white key 2.
That is, in this pressure sensor 70, as shown in FIG. 33, the detection characteristic of the pressure sensor 70 in the black key 3 (curve B4 indicated by a two-dot chain line in the figure) is the same as that of the pressure sensor 70 in the white key 2. From the detection characteristic (curve W4 shown by the solid line in the figure), on the side where the pressing force is weak (the left side in the figure), the keying force is shifted in the strong direction (the right direction in the figure). Even if there is a difference between the pressing forces F2 and F1 by the key 3 and the white key 2, the same electric resistance value can be obtained because the curves B4 and W4 are shifted.
[0050]
For this reason, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the lengths of the white key 2 and the black key 3 up to the key pressing positions 2a and 3a. Due to the difference between S1 and S2, the moment is different between the white key 2 and the black key 3, so that the pressing force F2 applied to the sensor sheet 18 corresponding to the black key 3 is applied to the sensor sheet 18 corresponding to the white key 2. Even if it is smaller than the applied pressing force F1, the electrical resistance value at the location corresponding to the black key 3 can be made smaller than the electrical resistance value at the location corresponding to the white key 3, whereby the black key 3 and the white key 2 can be reduced. Even if there is a difference between the pressing forces F2 and F1 due to the above, the density of the electrode portion 71 at the portion corresponding to the white key 2 and the black key 3 is appropriately set, and the portion corresponding to the white key 2 and the black key 3 By adjusting the electrical resistance value, the conduction state of the electrode part 71 by the pressure-sensitive layer 20 is made to be approximately the same. It is possible. As a result, as in the first embodiment, the pressure-sensitive sensor 70 outputs an electric resistance value of the same level, and the white key 2 and the black key 3 together with various effects are produced based on the electric resistance value. The sound can be emitted by giving a degree, and the musical sound can be emitted well.
[0051]
[Tenth embodiment]
Next, with reference to FIGS. 34 and 35, a tenth embodiment of the pressure-sensitive sensor of the present invention will be described. In this case, the same parts as those of the ninth embodiment shown in FIGS. 30 to 33 are denoted by the same reference numerals, and the description thereof is omitted.
This pressure-sensitive sensor 75 has a configuration in which a slit 76 is formed in the sensor sheet 18 at a peripheral position of a portion corresponding to the black key 3, and the other configuration is the same as that of the ninth embodiment.
That is, the pressure sensor 75 is formed such that the density of the electrode portions 71 at the locations corresponding to the black key 3 is larger than the density of the electrode portions 71 at the locations corresponding to the white key 2 and the location corresponding to the black key 3. Slits 76 are formed in a direction perpendicular to the arrangement direction of the keys 2 and 3 so that the sensor sheet 18 corresponding to the black key 3 can be formed. The sensor sheet 18 at the location corresponding to the white key 2 is more flexible than the sensor sheet 18. In this case, each slit 76 is formed such that the length in the direction orthogonal to the arrangement direction of the keys 2 and 3 is substantially the same as or slightly longer than the distance L between the spacers 17 in the same direction. .
[0052]
In such a pressure-sensitive sensor 75, the slit 76 is formed in the sensor sheet 18 located around the portion corresponding to the black key 3, so that the cross-sectional secondary moment I of the sensor sheet 18 at the portion corresponding to the black key 3 is obtained. But
I = (1/12) bhThree              ………… (2)
Therefore, b (the width of the sensor sheet 18 along the arrangement direction of the keys 2 and 3) in the equation (2) is reduced, thereby reducing the sectional moment I, and (3) in the first embodiment. , (4), the amount of deflection of the sensor sheet 18 at the location corresponding to the black key 3 increases. For this reason, when the felt 19 is pressed with the same force by the sensor pressing portions 6 of the keys 2 and 3, the sensor sheet 18 corresponding to the black key 3 bends more than the sensor sheet 18 corresponding to the white key. Moreover, since the density of the electrode portion 71 at the location corresponding to the black key 3 is higher than the density of the electrode portion 71 at the location corresponding to the white key 2, the electrical resistance value at the location corresponding to the black key 3 corresponds to the white key. It can be made smaller than the electric resistance value of the place to be.
[0053]
For this reason, when the front end portions 2a and 3a of the white key 2 and the black key 3 are pressed with the same force F0, the lengths of the white key 2 and the black key 3 up to the key pressing positions 2a and 3a. Due to the difference between S1 and S2, the moment is different between the white key 2 and the black key 3, so that the pressing force F2 applied to the sensor sheet 18 corresponding to the black key 3 is applied to the sensor sheet 18 corresponding to the white key 2. Even if it is smaller than the applied pressing force F1, the electrical resistance value at the location corresponding to the black key 3 can be made smaller than the electrical resistance value at the location corresponding to the white key 3, whereby the black key 3 and the white key 2 can be reduced. Even if there is a difference between the pressing forces F2 and F1 due to the above, the density of the electrode portion 71 at the location corresponding to the white key 2 and the black key 3 and the distance between the slits 76 of the sensor sheet 18 at the location corresponding to the black key 3 Is set appropriately, and the electrical resistance value corresponding to the white key 2 and the black key 3 is adjusted. By, the conduction state of the electrode portion 71 by the pressure sensitive layer 20 may be to the same extent. As a result, as in the first embodiment, the pressure-sensitive sensor 75 outputs the same electrical resistance value, and the white key 2 and the black key 3 together with the sound being sounded have various effects based on this electrical resistance value. The sound can be emitted by giving a degree, and the musical sound can be emitted well.
[0054]
In the first to tenth embodiments, the comb-like electrode portion 16 is formed on the upper surface of the pressure-sensitive sensor substrate 15, and the pressure-sensitive layer 20 is provided on the lower surface of the sensor sheet 18 facing the electrode portion 16. Although not limited to this, for example, as shown in FIGS. 36 (a) and 36 (b), one (lower) electrode 16a is formed on the substrate 15, and this The pressure-sensitive layer 20 is formed on the electrode 16a on the side, the other (upper) electrode 16b is formed on the lower surface of the sensor sheet 18 facing the electrode, and the upper electrode 16b is separated from and opposed to the pressure-sensitive layer 20. A pressure-sensitive sensor having a configuration may be used. In this case, the electrodes 16a and 16b may be formed in a simple flat plate shape or may be formed in a comb shape.
In such a pressure-sensitive sensor, when the felt 19 on the sensor sheet 18 is pressed by the sensor pressing portions 6 of the keys 2 and 3, the sensor sheet 18 is bent, and the upper electrode 16 b on the lower surface thereof becomes the pressure-sensitive layer 20. , The upper and lower electrodes 16a and 16b are conducted through the pressure sensitive layer 20. Even if such a pressure-sensitive sensor is used, the same effects as those of the first to tenth embodiments are obtained.
Moreover, it goes without saying that the present invention may be used in appropriate combination according to the above-described first to tenth embodiments and their modifications.
[0055]
【The invention's effect】
  As described above, according to the present invention, when the front ends of the white key and the black key are pressed with the same level of force, the white key and the black key are different due to the difference in length between the white key and the black key. The moment is different, and the pressing force applied to the flexible member at the location corresponding to the white key is different from the pressing force applied to the flexible member at the location corresponding to the black key.Since the opening area of the spacer corresponding to the black key is formed wider than the opening area of the spacer corresponding to the white key, the area corresponding to the black key is allowed due to the moment difference between the white key and the black key. Even if the pressing force applied to the flexible member is smaller than the pressing force applied to the flexible member at the location corresponding to the white key, the flexible member at the location corresponding to the black key is changed to the flexibility at the location corresponding to the white key. It is possible to bend more largely than the sexual member, and thereby a detection signal of the same level can be obtained.
[0056]
  Also,If the thickness of the flexible member at the location corresponding to the white key is thicker than the thickness of the flexible member at the location corresponding to the black key, the thickness of the black Even if the pressing force applied to the flexible member at the position corresponding to the key is smaller than the pressing force applied to the flexible member at the position corresponding to the white key, the flexible member at the position corresponding to the black key is the white key. Can be bent larger than the flexible member at a location corresponding to the above, and thus a detection signal of the same level can be obtained.further,If the flexible member located around the location corresponding to the black key has a slit, the flexible member located at the location corresponding to the black key will be affected by the difference in moment between the white key and the black key. Even if the pressing force applied is smaller than the pressing force applied to the flexible member at the location corresponding to the white key, the location corresponding to the black key is due to the slit of the flexible member located around the location corresponding to the black key. The flexible member can be bent more greatly than the flexible member at the portion corresponding to the white key, and thus a detection signal of the same level can be obtained.In addition, the distance between the electrode at the location corresponding to the black key and the pressure-sensitive layer facing away from the electrode is formed narrower than the distance between the electrode at the location corresponding to the white key and the pressure-sensitive layer facing away from it. If it is a structure, due to the difference in moment between the white key and the black key, the pressing force applied to the flexible member at the location corresponding to the black key is greater than the pressing force applied to the flexible member at the location corresponding to the white key. Even if it is small, the contact area and the contact pressure with respect to the pair of electrodes of the pressure-sensitive layer at the location corresponding to the black key are larger than the contact area and the contact pressure with respect to the pair of electrodes of the pressure-sensitive layer at the location corresponding to the white key. This makes it possible to obtain the same level of detection signal. Furthermore, if the spacer is formed of an elastic material and the elastic coefficient of the spacer corresponding to the black key is smaller than the elastic coefficient of the spacer corresponding to the white key, the white key and the black key Even if the pressing force applied to the flexible member at the location corresponding to the black key is smaller than the pressing force applied to the flexible member at the location corresponding to the white key due to the difference in moment, the spacer at the location corresponding to the black key is whitened. It can be elastically deformed more greatly than the spacer at the location with respect to the key, whereby a detection signal of the same degree can be obtained.
[0057]
  Also,A white key and a black key are provided between the flexible member and the buffer member, and when the pair of electrodes are conducted by the pressure-sensitive layer by pressing the front end portions of the white key and the black key with the same level of force. A regulating member that regulates the conduction state of the part corresponding to the key to the same extentHave thisThe restriction member has an opening formed at a position corresponding to the key, and an opening at a position corresponding to the black key among these openings.ButIf the structure is formed wider than the opening corresponding to the key, the white key causes the pressing force applied to the flexible member at the position corresponding to the black key due to the difference in moment between the white key and the black key. Even if it is smaller than the pressing force applied to the flexible member at the corresponding location, the flexible member at the location corresponding to the black key can be changed to the location corresponding to the white key due to the difference in the size of the opening of the regulating member. It is possible to bend more largely than the flexible member, thereby obtaining the same level of detection signal.
[0058]
  Further, if the restricting member is made of a flexible material and the thickness of the portion corresponding to the white key is formed to be thicker than the thickness of the portion corresponding to the black key, the white key and the black key Even if the pressing force applied to the flexible member at the location corresponding to the black key is smaller than the pressing force applied to the flexible member at the location corresponding to the white key due to the difference in moment, the restriction of the location corresponding to the black key is restricted. The member can be bent more greatly than the restricting member at the location corresponding to the white key, and thus a detection signal of the same level can be obtained. In addition, if the restricting member is made of a flexible material and has a slit formed at the peripheral position of the portion corresponding to the black key, the black key is changed due to the moment difference between the white key and the black key. Even if the pressing force applied to the regulating member at the corresponding location is smaller than the pressing force applied to the regulating member at the location corresponding to the white key, the location of the regulating member corresponding to the black key is regulated by the slit at the location corresponding to the white key. Can bend more than the partAs a result, the same level of detection signal can be obtained.
[0059]
  further,Each of the pair of electrodes has a comb-like shape and is formed in a state of being engaged with each other without contacting each other on the substrate, and a pressure-sensitive layer is provided on the lower surface of the flexible member so as to be opposed to the pair of electrodes, If the adjusting means has a configuration in which the engagement density of the pair of electrodes at the location corresponding to the black key is larger than the engagement density of the pair of electrodes at the location corresponding to the white key, the moment of the white key and the black key Due to the difference, even if the pressing force applied to the flexible member at the location corresponding to the black key is smaller than the pressing force applied to the flexible member at the location corresponding to the white key, the pressure-sensitive layer at the location corresponding to the black key The conduction density with respect to the pair of electrodes can be made larger than the conduction density with respect to the pair of electrodes of the pressure-sensitive layer in the portion corresponding to the white key, and thus a detection signal of the same level can be obtained.
[Brief description of the drawings]
FIG. 1 is a main part plan view showing spacers and electrode parts in a first embodiment of a pressure-sensitive sensor according to the present invention;
2 is a cross-sectional view of the pressure-sensitive sensor as viewed in the direction of arrows in FIG. 1, (a) is an enlarged cross-sectional view in the direction of arrows X1-X1 in FIG. 1, and (b) is in the direction of arrows X2-X2 in FIG. FIG.
FIG. 3 is a view for explaining the principle of bending of the sensor sheet of FIG. 2;
4 is a graph showing a characteristic of an electric resistance value with respect to a pressing force in the pressure sensitive sensor of FIG.
FIGS. 5A and 5B show modified examples of the pressure-sensitive sensor according to the first embodiment. FIG. 5A is a plan view of a main part showing spacers and electrode parts in the pressure-sensitive sensor of the first modified example. The principal part top view which showed the spacer and electrode part in the pressure-sensitive sensor of a modification.
FIG. 6 is a main part plan view showing spacers and electrode parts in a second embodiment of the pressure-sensitive sensor of the present invention.
7 is an enlarged cross-sectional view of the pressure-sensitive sensor as viewed in the direction of arrows X3-X3 in FIG.
8 shows each cross section of the pressure-sensitive sensor as viewed in the direction of arrows in FIG. 6, (a) is an enlarged cross-sectional view in the direction of arrows X4-X4 in FIG. 6, and (b) is in the direction of arrows X5-X5 in FIG. FIG.
FIG. 9 is a plan view showing a main part of a sensor sheet according to a third embodiment of the pressure sensor of the present invention.
10 is an enlarged cross-sectional view of the pressure-sensitive sensor as viewed in the direction of arrows X6-X6 in FIG.
11 is an enlarged cross-sectional view of the pressure-sensitive sensor as viewed in the direction of arrows X7-X7 in FIG.
FIG. 12 is an enlarged cross-sectional view of a main part of a pressure sensor showing a modification of the second embodiment.
FIG. 13 is a plan view of a principal portion showing spacers and electrode portions in a pressure sensitive sensor according to a fourth embodiment of the present invention.
14 is an enlarged cross-sectional view of the pressure sensor as viewed in the direction of arrows X8-X8 in FIG.
15 is a plan view of a principal part showing the regulating member of FIG. 13;
FIG. 16 is a main part plan view showing a regulating member showing a modification of the fourth embodiment.
FIG. 17 is a main part plan view showing a regulating member in a fifth embodiment of the pressure-sensitive sensor of the present invention;
18 is an enlarged cross-sectional view of the pressure sensor as viewed in the direction of arrows X9-X9 in FIG.
19 shows each cross section of the pressure-sensitive sensor in each arrow view of FIG. 17, (a) is an enlarged sectional view in the arrow direction X10-X10 in FIG. 17, and (b) is in the arrow view of X11-X11 in FIG. FIG.
FIG. 20 is a main part plan view showing a regulating member in a sixth embodiment of the pressure sensor of the present invention;
21 is an enlarged cross-sectional view of the pressure-sensitive sensor as viewed in the direction of arrows X12-X12 in FIG.
22 shows each cross section of the pressure-sensitive sensor as viewed in the direction of arrows in FIG. 20, (a) is an enlarged cross-sectional view in the direction of arrows X13-X13 in FIG. 20, and (b) is in the direction of arrows X14-X14 in FIG. FIG.
FIG. 23 is a main part plan view showing a modified example of the regulating member.
FIG. 24 is a main part plan view showing a spacer in a seventh embodiment of the pressure-sensitive sensor of the present invention;
25 shows each cross section of the pressure-sensitive sensor as viewed in the direction of arrows in FIG. 24, (a) is an enlarged cross-sectional view in the direction of arrows X15-X15 in FIG. 24, and (b) is in the direction of arrows X16-X16 in FIG. FIG.
FIG. 26 is a main part plan view showing spacers and electrode parts in a pressure sensitive sensor according to an eighth embodiment of the present invention;
27 is an enlarged cross-sectional view of the pressure sensor as viewed in the direction of arrows X17-X17 in FIG.
28 shows each cross section of the pressure-sensitive sensor as viewed from each arrow in FIG. 26, (a) is an enlarged cross-sectional view from the arrow X18-X18 in FIG. 26, and (b) is from the arrow X19-X19 in FIG. FIG.
FIG. 29 is a diagram showing a characteristic of an electric resistance value with respect to a pressing force in the pressure sensor according to the eighth embodiment.
FIG. 30 is a main part plan view showing spacers and electrode parts in a ninth embodiment of the pressure sensor of the present invention;
31 is an enlarged cross-sectional view of the pressure sensor as viewed in the direction of arrows X20-X20 in FIG.
32 is an enlarged cross-sectional view showing an operation state in which the pressure sensor is pressed in the direction of arrows X21-X21 in FIG. 30;
FIG. 33 is a diagram showing a characteristic of an electric resistance value with respect to a pressing force in the pressure sensor of the ninth embodiment.
FIG. 34 is a main part plan view showing a sensor sheet in a tenth embodiment of a pressure sensitive sensor of the present invention;
35 is an enlarged cross-sectional view of the pressure sensor as viewed in the direction of arrows X22-X22 in FIG.
36A and 36B show another basic configuration of the pressure-sensitive sensor according to the present invention, in which FIG. 36A is an enlarged cross-sectional view, and FIG.
FIG. 37 is a cross-sectional view of an electronic keyboard instrument using a conventional pressure sensor.
38 is a plan view of relevant parts in FIG. 37. FIG.
FIG. 39 shows the key pressing state of FIG. 37, (a) is a cross-sectional view showing a state where a white key is pressed, and (b) is a cross-sectional view showing a state where a black key is pressed.
FIG. 40 shows a conventional pressure-sensitive sensor, in which (a) is an enlarged cross-sectional view thereof, and (b) is an enlarged plan view taken along arrow X24-X24.
41 is an enlarged cross-sectional view showing an operating state in which the pressure sensor of FIG. 40 is pressed.
42 is a diagram showing basic characteristics of an electric resistance value with respect to a pressing force in the pressure-sensitive sensor of FIGS. 40 and 41. FIG.
43 is a block diagram showing a circuit configuration of the electronic keyboard instrument of FIG. 37. FIG.
44 is a diagram showing the characteristic of the electrical resistance value with respect to the pressing force of the pressure-sensitive sensor by the white key and the black key in the electronic keyboard instrument of FIG. 43. FIG.
[Explanation of symbols]
1 Keyboard chassis
2 White key
3 Black key
15 Board
16, 71 electrodes
16a, 16b, 71a, 71b A pair of electrodes
17, 31, 36, 61 Spacer
18, 41 Sensor sheet
19 Felt
20 Pressure sensitive layer
30, 35, 40, 45, 50, 55, 60, 65, 70, 75 Pressure sensor
46, 48, 51, 56, 58 Regulatory member
57 opening
59, 76 Slit
L1 Space between spacers corresponding to white keys
L2 Space between spacers corresponding to black keys
h1 Sensor sheet thickness corresponding to the white key
h2 Thickness of the sensor sheet at the location corresponding to the black key
h3 Thickness of the regulating member at the location corresponding to the white key
h4 Thickness of the regulating member at the location corresponding to the black key
H1 Spacing between electrode part and pressure sensitive layer corresponding to white key
H2 Spacing between the electrode and the pressure sensitive layer corresponding to the black key

Claims (9)

白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、
この基板上に設けられた一対の電極と、
この基板上に開口部を有するスペーサを介して前記一対の電極と離間対向した位置に設けられ、その上面を押鍵時に前記鍵により押圧された際に下方に撓む可撓性部材と、
この可撓性部材の上面に設けられ、押鍵時における鍵からの衝撃を吸収する緩衝部材と、
この可撓性部材の下面に設けられ、押鍵時に前記可撓性部材の撓みにより前記一対の電極に接触して当該一対の電極同士を導通させる感圧層と、
を有し、
前記黒鍵に対応する箇所の前記スペーサの開口領域を、前記白鍵に対応する箇所の前記スペーサの開口領域よりも広く形成したことを特徴とする感圧センサ。A plurality of keys with different lengths of white key and black key are arranged on the keyboard chassis in which the keys can be rotated in the vertical direction around the fulcrum at the same position. And a pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,
A pair of electrodes provided on the substrate;
A flexible member that is provided at a position facing and spaced apart from the pair of electrodes via a spacer having an opening on the substrate, and that flexes downward when the upper surface is pressed by the key when the key is pressed;
A buffer member that is provided on the upper surface of the flexible member and absorbs an impact from the key when the key is depressed;
A pressure-sensitive layer that is provided on the lower surface of the flexible member, contacts the pair of electrodes by bending of the flexible member when a key is pressed, and electrically connects the pair of electrodes;
Have
A pressure-sensitive sensor , wherein an opening area of the spacer at a position corresponding to the black key is formed wider than an opening area of the spacer at a position corresponding to the white key . 白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、
この基板上に設けられた一対の電極と、
この基板上に開口部を有するスペーサを介して前記一対の電極と離間対向した位置に設けられ、その上面を押鍵時に前記鍵により押圧された際に下方に撓む可撓性部材と、
この可撓性部材の上面に設けられ、押鍵時における鍵からの衝撃を吸収する緩衝部材と、
この可撓性部材の下面に設けられ、押鍵時に前記可撓性部材の撓みにより前記一対の電極に接触して当該一対の電極同士を導通させる感圧層と、
を有し、
前記白鍵に対応する箇所の前記可撓性部材の厚みを、前記黒鍵に対応する箇所の前記可撓性部材の厚みよりも厚く形成したことを特徴とする感圧センサ。 A plurality of keys with different lengths of white key and black key are arranged on the keyboard chassis in which the keys are arranged so as to be rotatable in the vertical direction around the fulcrum at the same position. And a pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,
A pair of electrodes provided on the substrate;
A flexible member that is provided at a position facing and spaced apart from the pair of electrodes via a spacer having an opening on the substrate, and that flexes downward when the upper surface is pressed by the key when the key is pressed;
A buffer member that is provided on the upper surface of the flexible member and absorbs an impact from the key when the key is depressed;
A pressure-sensitive layer that is provided on the lower surface of the flexible member, contacts the pair of electrodes by bending of the flexible member when a key is pressed, and electrically connects the pair of electrodes;
Have
A pressure-sensitive sensor , wherein a thickness of the flexible member at a location corresponding to the white key is formed to be greater than a thickness of the flexible member at a location corresponding to the black key . 白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、
この基板上に設けられた一対の電極と、
この基板上に開口部を有するスペーサを介して前記一対の電極と離間対向した位置に設けられ、その上面を押鍵時に前記鍵により押圧された際に下方に撓む可撓性部材と、
この可撓性部材の上面に設けられ、押鍵時における鍵からの衝撃を吸収する緩衝部材と、
この可撓性部材の下面に設けられ、押鍵時に前記可撓性部材の撓みにより前記一対の電極に接触して当該一対の電極同士を導通させる感圧層と、
を有し、
前記黒鍵に対応する箇所の周辺に位置する前記可撓性部材に、スリットを形成したことを特徴とする感圧センサ。 A plurality of keys with different lengths of white key and black key are arranged on the keyboard chassis in which the keys are arranged so as to be rotatable in the vertical direction around the fulcrum at the same position. And a pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,
A pair of electrodes provided on the substrate;
A flexible member that is provided at a position facing and spaced apart from the pair of electrodes via a spacer having an opening on the substrate, and that flexes downward when the upper surface is pressed by the key when the key is pressed;
A buffer member that is provided on the upper surface of the flexible member and absorbs an impact from the key when the key is depressed;
A pressure-sensitive layer that is provided on the lower surface of the flexible member, contacts the pair of electrodes by bending of the flexible member when a key is pressed, and electrically connects the pair of electrodes;
Have
A pressure-sensitive sensor , wherein a slit is formed in the flexible member located around a portion corresponding to the black key . 白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、
この基板上に設けられた一対の電極と、
この基板上に開口部を有するスペーサを介して前記一対の電極と離間対向した位置に設けられ、その上面を押鍵時に前記鍵により押圧された際に下方に撓む可撓性部材と、
この可撓性部材の上面に設けられ、押鍵時における鍵からの衝撃を吸収する緩衝部材と、
この可撓性部材の下面に設けられ、押鍵時に前記可撓性部材の撓みにより前記一対の電極に接触して当該一対の電極同士を導通させる感圧層と、
を有し、
前記スペーサを弾性材料で形成し、前記黒鍵に対応する箇所の前記スペーサの弾性係数を、前記白鍵に対応する箇所の前記スペーサの弾性係数よりも小さく形成したことを特徴とする感圧センサ。 A plurality of keys with different lengths of white key and black key are arranged on the keyboard chassis in which the keys are arranged so as to be rotatable in the vertical direction around the fulcrum at the same position. And a pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,
A pair of electrodes provided on the substrate;
A flexible member that is provided at a position facing and spaced apart from the pair of electrodes via a spacer having an opening on the substrate, and that flexes downward when the upper surface is pressed by the key when the key is pressed;
A buffer member that is provided on the upper surface of the flexible member and absorbs an impact from the key when the key is depressed;
A pressure-sensitive layer that is provided on the lower surface of the flexible member, contacts the pair of electrodes by bending of the flexible member when a key is pressed, and electrically connects the pair of electrodes;
Have
The pressure sensor is characterized in that the spacer is formed of an elastic material, and an elastic coefficient of the spacer at a position corresponding to the black key is smaller than an elastic coefficient of the spacer at a position corresponding to the white key. . 白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、
この基板上に設けられた一対の電極と、
この基板上に開口部を有するスペーサを介して前記一対の電極と離間対向した位置に設けられ、その上面を押鍵時に前記鍵により押圧された際に下方に撓む可撓性部材と、
この可撓性部材の上面に設けられ、押鍵時における鍵からの衝撃を吸収する緩衝部材と、
この可撓性部材の下面に設けられ、押鍵時に前記可撓性部材の撓みにより前記一対の電極に接触して当該一対の電極同士を導通させる感圧層と、
を有し、
前記黒鍵に対応する箇所における前記電極とこれに離間対向する前記感圧層との間隔を、前記白鍵に対応する箇所における前記電極とこれに離間対向する前記感圧層との間隔よりも狭く形成したことを特徴とする感圧センサ。 A plurality of keys with different lengths of white key and black key are arranged on the keyboard chassis in which the keys are arranged so as to be rotatable in the vertical direction around the fulcrum at the same position. And a pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,
A pair of electrodes provided on the substrate;
A flexible member that is provided at a position facing and spaced apart from the pair of electrodes via a spacer having an opening on the substrate, and that flexes downward when the upper surface is pressed by the key when the key is pressed;
A buffer member that is provided on the upper surface of the flexible member and absorbs an impact from the key when the key is depressed;
A pressure-sensitive layer that is provided on the lower surface of the flexible member, contacts the pair of electrodes by bending of the flexible member when a key is pressed, and electrically connects the pair of electrodes;
Have
The distance between the electrode at the position corresponding to the black key and the pressure-sensitive layer spaced apart from the electrode is larger than the distance between the electrode at the position corresponding to the white key and the pressure-sensitive layer opposed to the white key. A pressure-sensitive sensor characterized by being narrowly formed . 白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、
前記各鍵の下部に設けられた基板と、
この基板上に設けられた一対の電極と、
この基板上に開口部を有するスペーサを介して前記一対の電極と離間対向した位置に設けられ、その上面を押鍵時に前記鍵により押圧された際に下方に撓む可撓性部材と、
この可撓性部材の上面に設けられ、押鍵時における鍵からの衝撃を吸収する緩衝部材と、
この可撓性部材の下面に設けられ、押鍵時に前記可撓性部材の撓みにより前記一対の電極に接触して当該一対の電極同士を導通させる感圧層と、
前記可撓性部材と前記緩衝部材との間に設けられるとともに、前記鍵を押鍵した際の前記可撓性部材の撓み度合いを、前記白鍵を押鍵した場合より前記黒鍵を押鍵した場合の方が大きくなるよう規制する規制部材と、
を有し、
前記規制部材は、前記鍵に対応する箇所に開口部が形成され、これら開口部のうち、前記黒鍵に対応する箇所の前記開口部が、前記白鍵に対応する箇所の前記開口部よりも広く形成されていることを特徴とする感圧センサ。 A plurality of keys with different lengths of white key and black key are arranged on the keyboard chassis in which the keys are arranged so as to be rotatable in the vertical direction around the fulcrum at the same position. And a pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,
A substrate provided below each key;
A pair of electrodes provided on the substrate;
A flexible member that is provided at a position facing and spaced apart from the pair of electrodes via a spacer having an opening on the substrate, and that flexes downward when the upper surface is pressed by the key when the key is pressed;
A buffer member that is provided on the upper surface of the flexible member and absorbs an impact from the key when the key is depressed;
A pressure-sensitive layer that is provided on the lower surface of the flexible member, contacts the pair of electrodes by bending of the flexible member when a key is pressed, and electrically connects the pair of electrodes;
It is provided between the flexible member and the buffer member, and the degree of flexion of the flexible member when the key is pressed is set to be lower than that when the white key is pressed. A restricting member that restricts the size of the
Have
The restricting member has an opening formed at a position corresponding to the key, and among the openings, the opening at a position corresponding to the black key is more than the opening at a position corresponding to the white key. A pressure-sensitive sensor that is widely formed . 白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、
前記各鍵の下部に設けられた基板と、
この基板上に設けられた一対の電極と、
この基板上に開口部を有するスペーサを介して前記一対の電極と離間対向した位置に設けられ、その上面を押鍵時に前記鍵により押圧された際に下方に撓む可撓性部材と、
この可撓性部材の上面に設けられ、押鍵時における鍵からの衝撃を吸収する緩衝部材と、
この可撓性部材の下面に設けられ、押鍵時に前記可撓性部材の撓みにより前記一対の電極に接触して当該一対の電極同士を導通させる感圧層と、
前記可撓性部材と前記緩衝部材との間に設けられるとともに、前記鍵を押鍵した際の前記可撓性部材の撓み度合いを、前記白鍵を押鍵した場合より前記黒鍵を押鍵した場合の方が大きくなるよう規制する規制部材と、
を有し、
前記規制部材は、可撓性を有する材料からなり、前記白鍵に対応する箇所の厚みが、前記黒鍵に対応する箇所の厚みよりも厚く形成されていることを特徴とする感圧センサ。 A plurality of keys with different lengths of white key and black key are arranged on the keyboard chassis in which the keys are arranged so as to be rotatable in the vertical direction around the fulcrum at the same position. And a pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,
A substrate provided below each key;
A pair of electrodes provided on the substrate;
A flexible member that is provided at a position facing and spaced apart from the pair of electrodes via a spacer having an opening on the substrate, and that flexes downward when the upper surface is pressed by the key when the key is pressed;
A buffer member that is provided on the upper surface of the flexible member and absorbs an impact from the key when the key is depressed;
A pressure-sensitive layer that is provided on the lower surface of the flexible member, contacts the pair of electrodes by bending of the flexible member when a key is pressed, and electrically connects the pair of electrodes;
It is provided between the flexible member and the buffer member, and the degree of flexion of the flexible member when the key is pressed is set to be lower than that when the white key is pressed. A restricting member that restricts the size of the
Have
The pressure-sensitive sensor is characterized in that the regulating member is made of a material having flexibility, and a thickness of a portion corresponding to the white key is formed thicker than a thickness of a portion corresponding to the black key . 白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、
前記各鍵の下部に設けられた基板と、
この基板上に設けられた一対の電極と、
この基板上に開口部を有するスペーサを介して前記一対の電極と離間対向した位置に設けられ、その上面を押鍵時に前記鍵により押圧された際に下方に撓む可撓性部材と、
この可撓性部材の上面に設けられ、押鍵時における鍵からの衝撃を吸収する緩衝部材と、
この可撓性部材の下面に設けられ、押鍵時に前記可撓性部材の撓みにより前記一対の電極に接触して当該一対の電極同士を導通させる感圧層と、
前記可撓性部材と前記緩衝部材との間に設けられるとともに、前記鍵を押鍵した際の前記可撓性部材の撓み度合いを、前記白鍵を押鍵した場合より前記黒鍵を押鍵した場合の方が大きくなるよう規制する規制部材と、
を有し、
前記規制部材は、可撓性を有する材料からなり、前記黒鍵に対応する箇所の周辺位置にスリットが形成されていることを特徴とする感圧センサ。 A plurality of keys with different lengths of white key and black key are arranged on the keyboard chassis in which the keys are arranged so as to be rotatable in the vertical direction around the fulcrum at the same position. And a pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,
A substrate provided below each key;
A pair of electrodes provided on the substrate;
A flexible member that is provided at a position facing and spaced apart from the pair of electrodes via a spacer having an opening on the substrate, and that flexes downward when the upper surface is pressed by the key when the key is pressed;
A buffer member that is provided on the upper surface of the flexible member and absorbs an impact from the key when the key is depressed;
A pressure-sensitive layer that is provided on the lower surface of the flexible member, contacts the pair of electrodes by bending of the flexible member when a key is pressed, and electrically connects the pair of electrodes;
It is provided between the flexible member and the buffer member, and the degree of flexion of the flexible member when the key is pressed is set to be lower than that when the white key is pressed. A restricting member that restricts the size of the
Have
The pressure sensor is characterized in that the regulating member is made of a flexible material, and a slit is formed at a peripheral position of a portion corresponding to the black key . 白鍵および黒鍵の長さの異なる複数の鍵が同じ位置の支点を中心に上下方向に回動可能に配列された鍵盤シャーシ上に、前記支点から一定距離の位置で前記鍵の配列方向に沿って配置され、前記鍵が押鍵された際、前記鍵の押鍵力を検出する感圧センサであって、
前記各鍵の下部に設けられた基板と、
この基板上にスペーサを介して離間対向した状態で設けられ、押鍵時に前記鍵により押圧されて撓む可撓性部材と、
前記基板と前記可撓性部材との対向領域内に互いに接触することなく設けられた一対の電極と、
これら一対の電極のうちの少なくとも一方の電極に離間対向し、押鍵時に前記可撓性部材の撓みにより前記一対の電極を導通させる感圧層と、
を有し、
前記一対の電極は、それぞれ櫛歯状をなし、前記基板上に互いに接触することなく噛み合った状態で形成され、前記感圧層は、前記可撓性部材の下面に前記一対の電極に対し離間対向して設けられ、前記黒鍵に対応する箇所における前記一対の電極の噛み合い密度を、前記白鍵に対応する箇所における前記一対の電極の噛み合い密度よりも大きく形成したことを特徴とする感圧センサ。 A plurality of keys with different lengths of white key and black key are arranged on the keyboard chassis in which the keys are arranged so as to be rotatable in the vertical direction around the fulcrum at the same position. And a pressure-sensitive sensor that detects a key pressing force of the key when the key is pressed,
A substrate provided below each key;
A flexible member which is provided on the substrate in a state of being opposed to and spaced from each other via a spacer, and is bent by being pressed by the key when the key is pressed;
A pair of electrodes provided without being in contact with each other in a facing region of the substrate and the flexible member;
A pressure-sensitive layer that is spaced apart and opposed to at least one of the pair of electrodes and electrically connects the pair of electrodes by bending of the flexible member when the key is pressed;
Have
Each of the pair of electrodes has a comb-like shape and is formed on the substrate so as to be engaged with each other without being in contact with each other. The pressure sensitivity is characterized in that the engagement density of the pair of electrodes at a location corresponding to the black key is formed larger than the engagement density of the pair of electrodes at a location corresponding to the white key. Sensor.
JP06839199A 1999-03-15 1999-03-15 Pressure sensor Expired - Fee Related JP3757666B2 (en)

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JP3757666B2 true JP3757666B2 (en) 2006-03-22

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