JP4164946B2

JP4164946B2 - Pressure sensor

Info

Publication number: JP4164946B2
Application number: JP17244799A
Authority: JP
Inventors: 基中川; 孝明山本
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1999-06-18
Filing date: 1999-06-18
Publication date: 2008-10-15
Anticipated expiration: 2019-06-18
Also published as: JP2001004469A

Description

【０００１】
【発明の属する技術分野】
本発明は、樹脂フィルムを用いた感圧センサにおける配線膜構造に関する。本発明は、自動車における乗員検出や、乗員の体重、着座した時の重力バランス等を検出するセンサに用いることができる。
【０００２】
【従来の技術】
例えば、自動車における着座センサとして、樹脂フィルムを用いたメンブレンスイッチによる感圧センサが知られている。この感圧サンセは、通常、座席の面積の各部における受圧を検出するために複数の接点部が分散して配置されている。そして、各接点部に対して並列給電し、接点部の受圧による閉成状態に応じた接点部の電圧をそれぞれ検出することで、各部の受圧を検出している。
【０００３】
【発明が解決しようする課題】
しかしながら、上述のような感圧センサは、接点部、配線膜等の断線、短絡を検出するために、自己診断が行われている。しかしながら、接点部が開状態の時には、接点部に電流が流れないために、配線膜の断線検出をすることはできない。又、受圧状態では接点部が閉成されるために、配線膜の短絡検出をすることができない。
さらに、複数の接点部を有する場合には、それぞれの接点部の検出電圧が同一圧力を受ける場合には、同一であるように較正される必要があるが、この検出電圧の較正に補正抵抗が各給電配線膜に直列に挿入されている。又、接点部に設けられた感圧抵抗膜の温度特性を補償するための抵抗が必要となる。しかし、これらの出力感度補正、温度補正の抵抗は、全て、接点部に給電し、接点部の電圧を検出する検出装置に組み込まれており、抵抗の調整が複雑になり、且つ、検出装置における配線が複雑になり、装置自体の製造コストが増大するとう問題がある。
【０００４】
そこで、本発明の目的は、このような自己診断を可能とし、又は、出力特性を補正する抵抗を検出装置に設けるのではなく、感圧センサにおける配線膜と共に形成することで、抵抗値の調整、配線の簡略化を図り、この感圧センサを含む圧力検出装置の製造の容易化、寸法の低減，コスト低減を図ることである。
【０００５】
【課題を解決するための手段】
上記した課題を解決するための請求項１の発明は、上下一対の樹脂フィルムの内面に形成され、受圧に応じて閉成される接点部と、この接点部に接続する配線膜とを有する感圧センサにおいて、配線膜の一部として、抵抗素子膜を形成し、抵抗素子膜は、感圧センサの温度特性又は感度特性等の出力特性を補正するための抵抗としたことである。
【０００６】
従来は、感圧センサの接続される圧力検出装置に抵抗を設けていたところ、この抵抗自体を感圧センサの配線膜の一部として形成したので、製造が容易となる。又、検出装置には抵抗が必要でなくなるために、装置の小型化、製造の容易化、コストの低減を達成することができる。
感圧センサの温度特性又は感度特性等の出力特性を補正するための抵抗素子膜を感圧センサの配線膜の一部に形成したので、接点部の検出電圧から、非受圧時、受圧時にかかわらず、断線、短絡の自己診断を行うことが可能となる。請求項１と同様に外部に抵抗素子を必要としないことから、製造が容易であり、装置の小型化、コストの低減が達成される。
【０００７】
【０００８】
【０００９】
請求項２の発明は、一対の樹脂フィルムは第１樹脂フィルムと第２樹脂フィルムから成り、第１樹脂フィルムの内面に形成された感圧抵抗膜と、第２樹脂フィルムの内面に形成され、受圧時に前記感圧抵抗膜と接触することで短絡される配線膜の接触面とにより、接点部を形成したことを特徴とする。
この構成は、いわゆるショートバー接点方式の接点である。即ち、配線膜の一部である接触面が感圧抵抗膜により短絡されることから、受圧を検出する感圧センサである。このような感圧センサに抵抗素子膜を配線膜の一部に形成することで、上記の効果を達成することができる。
【００１０】
請求項３の発明は、一対の樹脂フィルムは第１樹脂フィルムと第２樹脂フィルムから成り、配線膜は第１樹脂フィルム及び第２樹脂フィルムの内面に形成され、その配線膜に連続し、受圧時に接触する対面する一対の接触面により接点部を形成したことを特徴とする。
この構成は、いわゆる対向接点方式の接点である。即ち、配線膜に連続した上下一対の対面した接触面が接点を構成する感圧センサである。このような感圧センサに抵抗素子膜を配線膜の一部に形成することで、上記の効果を達成することができる。
【００１１】
請求項４の発明は、接点部の一対の接触面の少なくとも一方の接触面を感圧抵抗膜で形成したことを特徴とする。これにより受圧の大きさにより抵抗値が変化して、一対の接触面間の電圧を検出することで、圧力の大きさを検出することが可能となる。このような感圧センサに抵抗素子膜を配線膜の一部に形成することで、上記の効果を達成することができる。
【００１２】
請求項５の発明は、接触面は、感圧抵抗膜の形成領域において蛇行して形成されていることを特徴とする。蛇行配線膜を接触面としたことから、感圧抵抗膜と多くの部分で接触可能となり、この部分の配線膜の断線があっても、感圧抵抗膜により配線膜間が短絡されるならば、圧力検出が可能なセンサとなる。このような感圧センサに抵抗素子膜を配線膜の一部に形成することで、上記の効果を達成することができる。
【００１３】
請求項６の発明は、接触面を、感圧抵抗膜の形成領域において、平行線状に形成したことを特徴とする。平行線状に形成していることから製造が容易であり、このような感圧センサに抵抗素子膜を配線膜の一部に形成することで、上記の効果を達成することができる。
【００１４】
【００１５】
請求項７の発明は、配線膜は接触面に対して給電する給電配線膜と接触面の電位を検出する検出配線膜とから成り、抵抗素子膜は前記出力特性を補正する抵抗であって、前記給電配線膜に直列に挿入されていることを特徴とする。
この構成により、接点が閉状態の時の接点電位をこの抵抗素子膜の抵抗値により調整することが可能となり、圧力−出力特性、即ち、感度特性を補正及び較正することが可能となる。この構造の感圧センサにさらに自己診断用の抵抗素子膜を形成すれば、自己診断が容易となる。これらの構成により、請求項１と同様な効果を達成することができる。
【００１６】
請求項８の発明は、抵抗素子膜は感圧抵抗膜と同一物質で構成されていることを特徴とする。
この構成により、接点が閉状態の時の感圧抵抗膜で決定される接点抵抗の温度特性と、抵抗素子膜との温度特性とを同一にしたため、抵抗素子膜と感圧抵抗膜との抵抗分割で決定される接点の検出電位は、両抵抗が温度に対して同一に変化するため、温度変動が補償されたものとなる。よって、温度変動があっても、検出圧力の温度変動がなくなり、検出精度が向上するという効果がある。しかも、この温度補償は、感圧センサの配線膜の一部として形成された抵抗素子膜で実現されるために、製造が容易であり、装置全体の小型化が達成でき、請求項１と同様な効果がある。
【００１７】
請求項９の発明は、樹脂フィルムにおいて各部の受圧を検出する接点部が分散して複数設けられており、給電配線膜は各接点部に対して並列に給電し、検出配線膜は各接点部のそれぞれに対して接続されていることを特徴とする。
この感圧センサは、複数の分散した位置における圧力を検出するために複数の接点部が存在する感圧センサである。この構成の感圧センサに対して、自己診断、又は、出力特性の補正のための抵抗素子膜を配線膜の一部として形成することで、外部抵抗の場合には抵抗を配置する複雑な回路を必要とするが、感圧センサに抵抗素子膜が内蔵されるために、外部回路の負担がなくなり、請求項１の効果をより効果的に達成することができる。
【００１８】
【００１９】
請求項１０の発明は、樹脂フィルムにおいて各部の受圧を検出する接点部が分散して複数設けられており、抵抗素子膜は、各接点部に対して共通に１つだけ設けられており、この抵抗素子膜の端子電位を検出する検出配線膜が形成されていることを特徴とする。
この構成では、この抵抗素子膜の端子電圧を参照電圧とすることで、各接点部の検出電圧と比較することで、温度補償の行われた出力を得ることができる。抵抗素子膜が１つに簡略化されていることから、感圧センサの構成が簡単となり、そのセンサの製造が容易となる。
【００２０】
請求項１１の発明は、請求項１の発明に、更に、別の抵抗素子膜として、感圧センサの自己診断のための抵抗である抵抗素子膜が設けられていることを特徴とする。この構成によれば、自己診断と出力特性の補正とを共に行うことができる感圧センサを製造容易且つ構造簡単にして供給することができる。
【００２１】
請求項１２の発明は、請求項７の発明に、更に、別の抵抗素子膜として、自己診断のための抵抗が、前記接触面に並列に接続されていることを特徴とする。これにより、請求項１１と同様な効果を奏することができる。
請求項１３の発明は、請求項１、２及び５の発明の構成を全て集めたものから「抵抗素子膜は、前記感圧センサの温度特性又は感度特性等の出力特性を補正するための抵抗である」との限定を除いたものであり、上述の効果を有する。
請求項１４の発明は、抵抗素子膜は自己診断のための抵抗であって、接触面に並列に接続されていることを特徴とする。この構成によれば、受圧がなく、接点が開状態であっても、この抵抗素子膜により電流がバイパスされるので、接点電位を検出することが可能となり、これにより配線膜の断線、配線膜間の短絡、接点部の短絡を検出することが可能となる。又、受圧時の接点の接触不良等がある場合にも、抵抗素子膜をバイパスする電流により接点の電位変化が検出でき、感圧センサの不良を検出することが可能となる。
請求項１５の発明は、請求項１、２及び９の発明の構成を全て集めたものから「抵抗素子膜は、前記感圧センサの温度特性又は感度特性等の出力特性を補正するための抵抗である」との限定を除いたものであり、上述の効果を有する。
請求項１６の発明は、請求項１３又は請求項１５の発明において抵抗素子膜を、感圧センサの自己診断のための抵抗としたものである。
自己診断のための抵抗素子膜を感圧センサの配線膜の一部に形成したので、接点部の検出電圧から、非受圧時、受圧時にかかわらず、断線、短絡の自己診断を行うことが可能となる。請求項１と同様に外部に抵抗素子を必要としないことから、製造が容易であり、装置の小型化、コストの低減が達成される。
請求項１７の発明は、追加事項として請求項６の追加事項を有するものであり、上述の効果を有する。
請求項１８の発明は、抵抗素子膜は自己診断のための抵抗であって、一対の接触面に並列に接続されていることを特徴とする。この構成によれば、受圧がなく、接点が開状態であっても、この抵抗素子膜により電流がバイパスされるので、接点電位を検出することが可能となり、これにより配線膜の断線、配線膜間の短絡、接点部の短絡を検出することが可能となる。又、受圧時の接点の接触不良等がある場合にも、抵抗素子膜をバイパスする電流により接点の電位変化が検出でき、感圧センサの不良を検出することが可能となる。
請求項１９の発明は、請求項１、３及び９の発明の構成を全て集めたものから「抵抗素子膜は、前記感圧センサの温度特性又は感度特性等の出力特性を補正するための抵抗である」との限定を除いたものであり、上述の効果を有する。
請求項２０の発明は、請求項１９の発明において抵抗素子膜を、感圧センサの自己診断のための抵抗としたものである。
自己診断のための抵抗素子膜を感圧センサの配線膜の一部に形成したので、接点部の検出電圧から、非受圧時、受圧時にかかわらず、断線、短絡の自己診断を行うことが可能となる。請求項１と同様に外部に抵抗素子を必要としないことから、製造が容易であり、装置の小型化、コストの低減が達成される。
請求項２１の発明は、追加事項として請求項４の追加事項を有するものであり、上述の効果を有する。
【００２２】
【発明の実施の形態】
以下、本発明の実施の形態について図面を参照して説明する。なお、本発明は下記実施例に限定されるものではない。
（第１実施例）
第１実施例は、請求項１３、１４、１６に記載の発明を具体化したものである。本実施例は自己診断用の抵抗素子膜を配線膜の一部として形成した感圧センサである。図１、図２、図３は本発明の具体的な実施例を模式的に示した、平面図、断面図、平面図である。本発明の感圧センサ１０は第１樹脂フィルム１１とそれに対面する第２樹脂フィルム１２を有している。図３に示すように、第１樹脂フィルム１１の内面上には、感圧抵抗膜２０が形成されており、図１に示すように、第２樹脂フィルム１２の内面上には配線膜１３、抵抗素子膜３０が形成されている。図３に示す第１樹脂フィムル１１と図１に示す第２樹脂フィルム１２とが、図２に示すように、スペーサフィルム１４を間に介在させて、接合されている。
【００２３】
第１、第２樹脂フィルム１１、１２は、ポリエチレンテレフタレート（ＰＥＴ）等で形成されており、感圧抵抗膜２０と抵抗素子膜３０は、同一物質で構成されており、例えば、カーボン粒子をポリエステル、ポリエーテル、ポリカーボネート等の樹脂系ポリマをバインダとして、混錬したものである。配線膜１３は、１０〜１００μｍ厚の銀、銅など導電率の高い金属材料で構成されている。
【００２４】
この銅、銀から成る配線膜１３は、樹脂系ポリマをバインダとした銀ペーストの印刷により形成するか、または、箔状にしたフォトマスク、光硬化性樹脂を用いてエッチング技術によって所定の形状にパターンニングされる。あるいは、無電解メッキ技術により、所定の形状にパターンニングしてもよい。又、感圧抵抗膜２０、抵抗素子膜３０も同様な方法で形成することができる。スクリーン印刷で形成する場合には、配線膜１３、感圧抵抗膜２０、抵抗素子膜３０は、１〜１００μｍ厚にスクリーン印刷し、印刷後、１００〜２００℃で乾燥させることによって形成することができる。スペーサフィルム１４は接着剤により第１樹脂フィルム１１と第２樹脂フィルム１２とに接合している。
【００２５】
配線膜１３は第２樹脂フィルム１２の内面上に図１に示すように形成されている。配線膜１３は感圧抵抗膜２０の上部領域において蛇行して形成されている。この領域に存在する配線膜１３が一対の接触面１３１、１３２を構成している。この一対の接触面１３１、１３２は受圧時に感圧抵抗膜２０と共に接触することで、接触面１３１、１３２間が導通する。即ち、接触面１３１、１３２が接点端子、感圧抵抗膜２０が可動接触片を構成する。従って、圧力を受けてスイッチ作用をする接点部は、配線膜１３の一部である接触面１３１、１３２、感圧抵抗膜２０とで構成されている。この接点部において、圧力が印加されていない時に、感圧抵抗膜２０と接触面１３１、１３２とが接触しないように、スペーサフィルム１４によりそれらの間に一定空隙が保持されている。
【００２６】
配線膜１３はアース配線膜１３３と給電／検出配線膜１３４とで構成されいる。給電／検出配線膜は、接点部に電圧を印加する給電と接点部の電圧の検出とを共通に行う配線膜である。そして、給電／検出配線膜１３４の先端部とアース配線膜１３３から分岐した分岐配線１３５との間に抵抗素子膜３０が形成されている。即ち、この抵抗素子膜３０は電気回路として見た場合に一対の接触面１３１、１３２で構成される接点端子に並列に配置されている。
【００２７】
図１の構成の感圧センサ１０の等価回路を図４に示す。Ｒｄが抵抗素子膜３０の抵抗であり、Ｒｆは感圧抵抗膜２０による抵抗である。この抵抗値は圧力により変化する。感圧センサ１０の端子は、図４の検出装置４０に接続されている。検出装置４０は負荷抵抗Ｒｏと電源ＶｅとＣＰＵ４１とで構成されている。感圧センサ１０の給電／検出配線膜１３４は負荷抵抗Ｒｏを介して電源Ｖｅに接続され、アース配線膜１３３が検出装置４０のアース端子に接続されている。
【００２８】
次に、この感圧センサ１０における自己診断機能について説明する。感圧センサ１０の接点部に圧力が印加されていない状態で、スイッチＳをオンとすると、電源Ｖｅから負荷抵抗Ｒｏ、抵抗素子膜３０の抵抗Ｒｄ、アースと電流は流れる。これにより、検出装置４０の検出端子ａの電圧は、電圧Ｖｅを負荷抵抗Ｒｏと抵抗Ｒｄとで分圧した値となる。この分圧電圧が検出されれば、全ての配線膜１３に断線が発生していないと判断される。一方、電源電圧Ｖｅが検出された場合には、配線膜１３のどこかに断線があると判断することが可能となる。一方、配線膜１３において、給電／検出配線膜１３４とアース配線膜１３３とが短絡している場合には、端子ａの検出電圧は上記の分圧電圧ではなくアース電位となるため、これにより、短絡故障を判断することが可能となる。
【００２９】
又、接点部に圧力が印加された状態では、端子ａにおける検出電圧は、正常であれば、電圧Ｖｅの負荷抵抗Ｒｏと抵抗Ｒｄとの分圧電圧ＶＨと、負荷抵抗Ｒｏと感圧抵抗膜２０の抵抗Ｒｆの最小値とによる分圧電圧ＶＬとの間の電圧が検出される。よって、分圧電圧ＶＨよりも十分に高い電圧が検出されれば断線であり、分圧電圧ＶＬよりも十分に低い電圧が検出されば、短絡と判断できる。
【００３０】
このようにして、感圧センサ１０における配線膜１３の一部として抵抗素子膜３０を接点間に並列に接続することで、感圧センサの自己診断を容易且つ正確に実施することが可能となる。抵抗Ｒｄを外部の検出装置４０に設けているのではなく、抵抗Ｒｄは感圧抵抗膜２０の形成工程と同一工程で配線膜１３の一部として形成されていることから、検出装置４０の構成が簡単となり、小型化、製造の容易化、コストの低下を達成することができる。
【００３１】
（第２実施例）
第２実施例は、第１実施例における接点部を複数分散配置した感圧センサである。図５に平面構成を図６にその等価回路を示す。各接点部１，２，３において、抵抗素子膜３０から成る抵抗Ｒｄ１，Ｒｄ２，Ｒｄ３が、それぞれ、各接点に対して並列に接続されている。アース配線膜１３３は３つの接点部１，２，３を周回し且つ連続している。給電／検出配線膜１３４は、図５に図示すように各接点部１，２，３に対して接続された給電／検出配線膜１３４１，１３４２，１３４３とで構成されている。等価回路は、３つの接点部１，２，３に対して並列に構成されているだけで、１つの接点部だけを見ると第１実施例と同一である。よって、第１実施例で説明したのと同一方法により、複数の接点部が分散配置されている場合にも、各接点部に対する自己診断を実施することが可能である。感圧センサ１０の内部に配線膜の一部として抵抗素子膜を形成する本実施例は、接点部が多くなるほど、外部の抵抗を削減できることから、第１実施例の述べた効果がより大きく達成されることになる。
【００３２】
（第３実施例）
次に、第３実施例について説明する。本実施例は、請求項１７の発明を具体化したものである。第１実施例と異なる点は、接点部の接点構造が異なるだけである。第１実施例と同一の機能を有する部分には同一の符合が付けられている。
図７に示すように、接点部において、第１実施例では配線膜１３が蛇行して形成されているのに対して、本実施例では、一対の接触面１３１と接触面１３２とが平行線状に形成されている。この実施例においても、抵抗素子膜３０は一対の接触面１３１、１３２とで構成される接点端子に電気的に並列に配置されている。本実施例においても、第１実施例と同様な作用効果が得られる。
【００３３】
（第４実施例）
第４実施例は、第３実施例の構造の接点部を第２実施例と同様に複数分散配置したものである。上記実施例と同一の機能を有する部分には同一の符合が付けられている。図８にその平面図を示す。等価回路は、図６と同一である。よって、本実施例も第２実施例と同様な作用効果を有する。
【００３４】
（第５実施例）
第５実施例は、請求項１８の発明を具体化したものである。本実施例は、いわゆる対向接点型の感圧センサである。図９にその構成の平面図を、図１０に接点部の断面図を、図１１にその等価回路を示す。上記実施例と同一の機能を有する部分は同一の符合が付されている。第１樹脂フィルム１１に、アース配線膜１３３と感圧抵抗膜２０１とが形成されており、第２樹脂フィルム１２に、給電／検出配線膜１３４１，１３４２，１３４３と感圧抵抗膜２０２が形成されている。そして、各接点部においては、アース配線膜１３３の上に各感圧抵抗膜２０１が形成されており、各給電／検出配線膜の上に各感圧抵抗膜２０２が形成されている。一対の対向した感圧抵抗膜２０１，２０２により接点端子が構成されている。各抵抗素子膜３０は、各給電／検出配線膜１３４１，１３４２，１３４３とアース配線膜１３３との間に形成されており、各接点部の接点端子に対して電気的に並列に配設されている。給電／検出配線膜とアース配線膜とは図１０に示すように同一面上に存在しないため、抵抗素子膜３０はスペーサフィルム１４のように、両側で給電／検出配線膜とアース配線膜とにそれぞれ接続されている。
【００３５】
このような感圧センサ１０の等価回路は図１１に示すようになるので、複数の接点部が分散配置された上記実施例と全く同様な効果を有する。
【００３６】
（第６実施例）
第６実施例は、抵抗素子膜を温度補償、又は、感度補償等の出力特性の補償用の抵抗としたものである。本実施例は、請求項７の発明を具体化したものである。上記実施例と同一の機能を有する部分には同一の符合が付されている。図１２に示すように、接点部の構造は、第３実施例と同じくショートバー接点方式であり、接触面１３２、１３１を平行線状としたものである。本実施例では、第３実施例の給電／検出配線膜１３４が給電配線膜１３６と検出配線膜１３７とに分けられ、検出配線膜１３７の先端が接点を構成する接触面１３１となっている。そして、この接触面１３１には抵抗素子膜３１を介して給電され電圧が印加されるように構成されている。この抵抗素子膜３１が出力特性補償用の抵抗となる。
【００３７】
等価回路は図１３に示すようになる。抵抗Ｒｃが抵抗素子膜３１で構成された抵抗であり、電源Ｖｅから給電配線膜１３６、抵抗Ｒｃ、接点部、アース配線膜１３３と給電されている。そして、接点部の高電圧が印加される側の接触面１３１の電圧が検出配線膜１３７を介して検出装置４０のＣＰＵ４１に入力している。抵抗素子膜３１と感圧抵抗膜２０は同一材料で構成されているので、抵抗Ｒｃと抵抗Ｒｆとの温度係数αは等しくなる。よって、検出電圧Ｖｏは電源電圧Ｖｅを抵抗Ｒｃと抵抗Ｒｆとで分圧した電圧であるので、温度Ｔにおける検出電圧は次式のようになる。
【００３８】
【数１】
Ｖｏ＝｛２Ｒｆ〔１＋α(Ｔ−Ｔ₀)〕｝・Ｖｅ／｛(Ｒｃ＋２Ｒｆ)〔１＋α(Ｔ−Ｔ₀)〕｝
＝２Ｒｆ・Ｖｅ／(Ｒｃ＋２Ｒｆ)
但し、Ｔ₀は一次温度係数αを定義する温度である。
【００３９】
となり、検出電圧Ｖｏは温度の関数ではなくなる。このようにして、感圧センサ１０の内部に温度補償用の抵抗素子膜３１を設けたことから、外部の検出装置４０の構成が極めて簡単となる。又、抵抗素子膜３１は接点部に近い位置に配置されることから、感圧抵抗膜２０と抵抗素子膜３１との温度が等しくなり、正確な温度補償を行うことができる。このように構成したことから、上記実施例と同じく、製造を容易にし、且つ、装置の小型化、コストの低減を図ることが可能となる。
【００４０】
（第７実施例）
第７実施例は、第６実施例において、接点部を複数、分散して配置したものである。本実施例は、請求項９の発明を具体化したものである。上記実施例と同一の機能を有する部分には同一の符合が付されている。図１４に示すように、図１２の構成の接点部が複数、分散配置されている。各接点部１，２，３に対して、それぞれ、給電配線膜１３６１，１３６２，１３６３と、検出配線膜１３７１，１３７２，１３７３とが配設されており、各給電配線膜と各検出配線膜との間に抵抗素子膜３１による抵抗Ｒｃ１，抵抗Ｒｃ２，抵抗Ｒｃ３が配設されている。この感圧センサ１０の等価回路は図１５に示す通りである。各接点部からの各検出電圧Ｖ１，Ｖ２，Ｖ３は、上述した第６実施例と同様に、温度変動がない。従って、正確な温度補償を行うことができる。又、多数の温度補償用の抵抗が感圧センサの内部に配線膜の一部として形成されていることから、外部装置の構成がより簡単となる。従って、上記した実施例と同様な効果を奏する。
【００４１】
（第８実施例）
第８実施例は、接点構造を第５実施例と同様に対向型としたものである。請求項３の発明を具体化したものである。上記実施例と同一の機能を有する部分には同一の符合が付されている。第７実施例と異なる点は、第７実施例では、給電配線膜と検出配線膜とが同一の樹脂フィルムに形成されているために、配線の立体交差ができないために、各接点部に対して給電配線膜をそれぞれ配線する必要があった。この給電配線膜を共通化するために、本実施例では、第１樹脂フィルム１１にアース配線膜１３３と共通の給電配線膜１３６が配設され、第２樹脂フィルム１２に各接点部に対する検出配線膜１３７１，１３７２，１３７３が配設されていることを特徴とする。そして、図１６の部分Ａの断面を示す図１７から理解されるように、各接点部の各抵抗素子膜３２が共通の給電配線膜１３６と各検出配線膜１３７１，１３７２，１３７３とで両側から挟まれるように配設されている。このような構成により、共通の給電配線膜１３６一本として感圧センサ内の配線を簡略化でき、より、配線密度を向上させることができる。
【００４２】
（第９実施例）
第９実施例は、出力特性補償用の抵抗素子膜を１つに共通化したものである。本実施例は請求項１０の発明を具体化したものである。上記の第７、第８実施例では、温度補償用の抵抗素子膜が各接点部毎に設けられている。しかし、本実施例では、図１８に示すように、各接点部１，２，３に対して、共通の抵抗素子膜３３が形成されている。この抵抗素子膜３３は参照電圧配線膜１３８とアース配線膜１３２との間に形成されている。上記実施例と同一の機能を有する部分には同一の符合が付されている。この感圧センサ１０の等価回路は図１９に示すようになる。抵抗素子膜３３による抵抗Ｒｒは、感圧抵抗膜２０の抵抗Ｒｆと同一温度係数を有するので、温度変動による参照電圧Ｖｒの電圧変化割合は、各接点部の検出電圧Ｖ１、Ｖ２、Ｖ３の電圧変化割合と等しくなる。従って、ほぼ、２Ｒｆ＝Ｒｒ（２Ｒｆは感圧抵抗膜２０の全体の抵抗値で標準圧が印加された時の値）に設定すれば、この電圧比Ｖ１／Ｖｒ、Ｖ２／Ｖｒ、Ｖ３／Ｖｒは、温度によらず、ほぼ一定となる。検出装置４０のＣＰＵ４１によりこの電圧比によって各接点部で受ける圧力を検出することで温度特性が補償されたものとなる。
【００４３】
（第１０実施例）
本実施例は、請求項１１、１２の発明を具体化したものである。即ち、第２実施例における自己診断のための抵抗である抵抗素子膜と、第７実施例における温度特性又は感度特性等の出力特性を補正するための抵抗である抵抗素子膜とが同時に配線膜の一部として形成されたものである。第２実施例、及び、第７実施例と同一機能を有する部分には同一符合が付されている。この感圧センサの等価回路は図２１に示すものとなる。各接点部１，２，３において、抵抗素子膜３０から成る抵抗Ｒｄ１，Ｒｄ２，Ｒｄ３が、それぞれ、各接点に対して並列に接続されている。アース配線膜１３３は３つの接点部１，２，３を周回し且つ連続している。各接点部１，２，３に対して、それぞれ、給電配線膜１３６１，１３６２，１３６３と、検出配線膜１３７１，１３７２，１３７３とが配設されており、各給電配線膜と各検出配線膜との間に抵抗素子膜３１による抵抗Ｒｃ１，抵抗Ｒｃ２，抵抗Ｒｃ３が配設されている。
【００４４】
各接点部からの各検出電圧Ｖ１，Ｖ２，Ｖ３は、上述した第７実施例と同様に、温度変動がない。従って、正確な温度補償を行うことができる。又、多数の温度補償用の抵抗が感圧センサの内部に配線膜の一部として形成されていることから、外部装置の構成がより簡単となる。従って、上記した実施例と同様な効果を奏する。
又、第２実施例で説明したのと同一方法により、各接点部に対する自己診断を実施することが可能である。
感圧センサ１０の内部に配線膜の一部として自己診断用と出力特性を補正する抵抗として機能する抵抗素子膜を形成する本実施例は、接点部が多くなるほど、外部の抵抗を削減できることから、より外部の検出装置の構成が簡略化できより大きな効果が達成されることになる。
尚、実施例を第８実施例のように対向接点型の感圧センサとするならば、次のように構成すれば良い。図１６において、各接点部において抵抗素子膜３２よりも接点に近いところで接点間に並列に自己診断用の抵抗素子膜を追加する。これにより、出力特性補償用の抵抗としての抵抗素子膜と、自己診断用の抵抗としての抵抗素子膜とを同時に形成できる。しかもこの場合には、給電配線膜は１本に共通化できる。この自己診断用の抵抗素子膜も図１７に示すように２つの樹脂フィルムの間に配設されることになる。
【００４５】
さらに、上記第１実施例〜第５実施例の自己診断のための抵抗素子膜と、第６実施例から第９実施例の出力特性の補償のための抵抗素子膜とを、任意に組み合わせて設けても良い。この場合に、各実施例の任意の組み合わせをすることが可能である。
【００４６】
（変形例）
上記第６実施例〜第９実施例は、温度特性の補償について述べたが、圧力に対する検出電圧の比、即ち、感度調整のための抵抗として用いることも可能である。又、複数接点部を有する場合には、各接点部に対する感度を均一にするための調整抵抗として用いることも可能である。
【図面の簡単な説明】
【図１】本発明の具体的な第１実施例にかかる感圧センサの構造を示した平面図。
【図２】第１実施例の感圧センサの断面図。
【図３】第１実施例の感圧センサの第１樹脂フィルムの構成を示した平面図。
【図４】第１実施例の感圧センサの等価回路図。
【図５】本発明の具体的な第２実施例にかかる感圧センサの構造を示した平面図。
【図６】第２実施例の感圧センサの等価回路図。
【図７】本発明の具体的な第３実施例にかかる感圧センサの構造を示した平面図。
【図８】本発明の具体的な第４実施例にかかる感圧センサの構造を示した平面図。
【図９】本発明の具体的な第５実施例にかかる感圧センサの構造を示した平面図。
【図１０】第５実施例の感圧センサの断面図。
【図１１】第５実施例の感圧センサの等価回路図。
【図１２】本発明の具体的な第６実施例にかかる感圧センサの構造を示した平面図。
【図１３】第６実施例の感圧センサの等価回路図。
【図１４】本発明の具体的な第７実施例にかかる感圧センサの構造を示した平面図。
【図１５】第７実施例の感圧センサの等価回路図。
【図１６】本発明の具体的な第８実施例にかかる感圧センサの構造を示した平面図。
【図１７】第８実施例の感圧センサの断面図。
【図１８】本発明の具体的な第９実施例にかかる感圧センサの構造を示した平面図。
【図１９】第９実施例の感圧センサの等価回路図。
【図２０】本発明の具体的な第１０実施例にかかる感圧センサの構造を示した平面図。
【図２１】第１０実施例の感圧センサの等価回路図。
【符合の簡単な説明】
１，２，３…接点部
１０…感圧センサ
１１…第１樹脂フィルム
１２…第２樹脂フィルム
１３…配線膜
２０，２０１，２０２…感圧抵抗膜
３０，３１，３２，３３…抵抗素子膜
１３１，１３２…接触面
１３３…アース配線膜
１３４…給電／検出配線膜
１３４１，１３４２，１３４３…給電／検出配線膜
１３６，１３６１，１３６２，１３６３…給電配線膜
１３７，１３７１，１３７２，１３７３…検出配線膜[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a wiring film structure in a pressure sensitive sensor using a resin film. INDUSTRIAL APPLICABILITY The present invention can be used as a sensor for detecting occupant detection in an automobile, occupant weight, gravity balance when seated, and the like.
[0002]
[Prior art]
  For example, a pressure-sensitive sensor using a membrane switch using a resin film is known as a seating sensor in an automobile. In the pressure-sensitive sensation, a plurality of contact parts are usually arranged in a distributed manner in order to detect pressure reception at each part of the seat area. Then, power is supplied to each contact portion in parallel, and the pressure at each contact portion is detected by detecting the voltage at the contact portion according to the closed state due to the pressure received at the contact portion.
[0003]
[Problems to be solved by the invention]
  However, the pressure sensor as described above is self-diagnosed in order to detect disconnection and short circuit of the contact portion and the wiring film. However, when the contact portion is in the open state, no current flows through the contact portion, so that the disconnection of the wiring film cannot be detected. Further, since the contact portion is closed in the pressure receiving state, it is impossible to detect a short circuit of the wiring film.
  Furthermore, in the case of having a plurality of contact portions, if the detected voltage at each contact portion is subjected to the same pressure, it is necessary to be calibrated to be the same. Each power supply wiring film is inserted in series. In addition, a resistance for compensating the temperature characteristics of the pressure-sensitive resistance film provided at the contact portion is required. However, these output sensitivity correction and temperature correction resistors are all incorporated in a detection device that supplies power to the contact portion and detects the voltage of the contact portion, making the adjustment of the resistance complicated and in the detection device. There is a problem that the wiring becomes complicated and the manufacturing cost of the device itself increases.
[0004]
  Accordingly, an object of the present invention is to enable such self-diagnosis or to adjust the resistance value by forming a resistor for correcting output characteristics together with a wiring film in a pressure-sensitive sensor, instead of providing a resistor for correcting output characteristics. It is intended to simplify wiring, to facilitate manufacture of a pressure detection device including the pressure sensor, to reduce dimensions, and to reduce costs.
[0005]
[Means for Solving the Problems]
  The invention according to claim 1 for solving the above-described problem has a feeling of having a contact portion formed on the inner surfaces of a pair of upper and lower resin films and closed according to pressure reception, and a wiring film connected to the contact portion. In a pressure sensor, a resistive element film is formed as part of the wiring filmThe resistance element film is a resistor for correcting output characteristics such as temperature characteristics or sensitivity characteristics of the pressure sensor.It is that.
[0006]
  Conventionally, when a resistance is provided in the pressure detection device to which the pressure sensor is connected, since the resistor itself is formed as a part of the wiring film of the pressure sensor, manufacturing is facilitated. In addition, since no resistance is required for the detection device, it is possible to reduce the size of the device, facilitate manufacturing, and reduce costs.
  Since the resistive element film for correcting the output characteristics such as the temperature characteristics or sensitivity characteristics of the pressure sensor is formed on a part of the wiring film of the pressure sensor, it is affected by the detection voltage of the contact part when not receiving pressure or receiving pressure. It is possible to perform self-diagnosis of disconnection and short circuit. Since no resistance element is required outside as in the case of the first aspect, the manufacturing is easy, and the device can be reduced in size and cost.
[0007]
[0008]
[0009]
  Claim 2In the invention of the present invention, the pair of resin films are composed of a first resin film and a second resin film, and are formed on the inner surface of the second resin film and the pressure sensitive resistance film formed on the inner surface of the first resin film. Contact with pressure sensitive resistance filmIs short-circuitedWiring filmofContact surfaceAnd byThe contact portion is formed.
  This configuration is a so-called short bar contact type contact. That is, the contact surface that is a part of the wiring film is short-circuited by the pressure-sensitive resistance film, and thus is a pressure-sensitive sensor that detects pressure reception. The above effect can be achieved by forming the resistance element film on a part of the wiring film in such a pressure sensitive sensor.
[0010]
  Claim 3In the present invention, the pair of resin films is composed of the first resin film and the second resin film, and the wiring film is formed on the inner surfaces of the first resin film and the second resin film, is continuous with the wiring film, and contacts when receiving pressure. A contact portion is formed by a pair of contact surfaces facing each other.
  This configuration is a so-called opposed contact type contact. That is, a pair of upper and lower contact surfaces that are continuous with the wiring film is a pressure-sensitive sensor that constitutes a contact point. The above effect can be achieved by forming the resistance element film on a part of the wiring film in such a pressure sensitive sensor.
[0011]
  Claim 4This invention is characterized in that at least one contact surface of the pair of contact surfaces of the contact portion is formed of a pressure-sensitive resistance film. As a result, the resistance value changes depending on the magnitude of the pressure received, and the magnitude of the pressure can be detected by detecting the voltage between the pair of contact surfaces. The above effect can be achieved by forming the resistance element film on a part of the wiring film in such a pressure sensitive sensor.
[0012]
  Claim 5According to the present invention, the contact surface is formed to meander in the formation region of the pressure-sensitive resistance film. Since the serpentine wiring film is used as a contact surface, it is possible to contact the pressure-sensitive resistance film at many parts. Even if the wiring film at this part is disconnected, the wiring film is short-circuited by the pressure-sensitive resistance film. It becomes a sensor capable of detecting pressure. The above effect can be achieved by forming the resistance element film on a part of the wiring film in such a pressure sensitive sensor.
[0013]
  Claim 6This invention is characterized in that the contact surface is formed in parallel lines in the formation region of the pressure-sensitive resistance film. Since it is formed in parallel lines, it is easy to manufacture, and the above effect can be achieved by forming a resistive element film on a part of the wiring film in such a pressure sensitive sensor.
[0014]
[0015]
  Claim 7The invention of the wiring filmIs closeIt consists of a power supply wiring film that supplies power to the touch surface and a detection wiring film that detects the potential of the contact surface, and the resistance element film is a resistor that corrects the output characteristics and is inserted in series with the power supply wiring film. It is characterized by being.
  With this configuration, the contact potential when the contact is in the closed state can be adjusted by the resistance value of the resistance element film, and the pressure-output characteristic, that is, the sensitivity characteristic can be corrected and calibrated. If a resistance element film for self-diagnosis is further formed on the pressure-sensitive sensor having this structure, self-diagnosis is facilitated. With these configurations, an effect similar to that of the first aspect can be achieved.
[0016]
  Claim 8According to the present invention, the resistance element film is made of the same material as the pressure-sensitive resistance film.
  With this configuration, the temperature characteristics of the contact resistance determined by the pressure-sensitive resistance film when the contact is in the closed state and the temperature characteristics of the resistance element film are the same, so the resistance between the resistance element film and the pressure-sensitive resistance film The detected potential of the contact determined by the division is one in which the temperature fluctuation is compensated for because both resistances change the same with respect to the temperature. Therefore, even if there is a temperature fluctuation, there is an effect that the temperature fluctuation of the detected pressure is eliminated and the detection accuracy is improved. In addition, since this temperature compensation is realized by a resistive element film formed as a part of the wiring film of the pressure-sensitive sensor, it is easy to manufacture and can achieve downsizing of the entire device, and the same as in claim 1 There is a great effect.
[0017]
  Claim 9In the present invention, a plurality of contact portions for detecting the pressure received at each portion are dispersed in the resin film, the power supply wiring film feeds power to each contact portion in parallel, and the detection wiring film is applied to each contact portion. They are connected to each other.
  This pressure-sensitive sensor is a pressure-sensitive sensor having a plurality of contact portions in order to detect pressures at a plurality of dispersed positions. For this type of pressure-sensitive sensor, a complicated circuit that arranges resistors in the case of external resistors by forming a resistive element film as part of the wiring film for self-diagnosis or correction of output characteristics However, since the resistance element film is built in the pressure sensor, the burden on the external circuit is eliminated, and the effect of claim 1 can be achieved more effectively.
[0018]
[0019]
  Claim 10The invention ofIn the resin film, there are a plurality of dispersed contact portions that detect the pressure of each part,Only one resistive element film is provided in common for each contact portion, and a detection wiring film for detecting a terminal potential of the resistive element film is formed.
  In this configuration, by using the terminal voltage of the resistance element film as a reference voltage, an output subjected to temperature compensation can be obtained by comparing with the detection voltage of each contact portion. Since the resistive element film is simplified to one, the configuration of the pressure-sensitive sensor is simplified, and the manufacture of the sensor is facilitated.
[0020]
  Claim 11The invention ofIn the invention of claim 1, as another resistive element film,Resistive element film as resistance for self-diagnosis of pressure-sensitive sensorIs providedIt is characterized by that. According to this configuration, it is possible to supply a pressure-sensitive sensor capable of performing both self-diagnosis and output characteristic correction with ease of manufacture and structure.
[0021]
  Claim 12The invention ofAccording to the seventh aspect of the present invention, as another resistive element film, a resistor for self-diagnosis is connected in parallel to the contact surface.It is characterized by that. ThisClaim 11The same effect can be achieved.
  The invention of claim 13 is a collection of all the configurations of the inventions of claims 1, 2 and 5: “The resistance element film is a resistor for correcting output characteristics such as temperature characteristics or sensitivity characteristics of the pressure-sensitive sensor. The above-mentioned effect is obtained.
  The invention according to claim 14 is characterized in that the resistive element film is a resistor for self-diagnosis and is connected in parallel to the contact surface. According to this configuration, even if there is no pressure reception and the contact is in an open state, the current is bypassed by this resistive element film, so that the contact potential can be detected. It becomes possible to detect a short circuit between them and a short circuit between contact points. In addition, even when there is a contact failure at the time of pressure reception, a change in the potential of the contact can be detected by a current bypassing the resistance element film, and a failure of the pressure sensor can be detected.
  The invention of claim 15 is a collection of all the configurations of the inventions of claims 1, 2 and 9: “The resistance element film is a resistor for correcting output characteristics such as temperature characteristics or sensitivity characteristics of the pressure-sensitive sensor. The above-mentioned effect is obtained.
  A sixteenth aspect of the present invention is the invention according to the thirteenth or fifteenth aspect, wherein the resistance element film is a resistance for self-diagnosis of the pressure-sensitive sensor.
  Since the resistive element film for self-diagnosis is formed on part of the wiring film of the pressure sensor, self-diagnosis of disconnection and short-circuit can be performed from the detection voltage of the contact part regardless of whether it is not receiving pressure or not. It becomes. Since no resistance element is required outside as in the case of the first aspect, the manufacturing is easy, and the device can be reduced in size and cost.
  The invention of claim 17 has the additional matter of claim 6 as an additional matter, and has the above-described effect.
  The invention according to claim 18 is characterized in that the resistive element film is a resistor for self-diagnosis and is connected in parallel to a pair of contact surfaces. According to this configuration, even if there is no pressure reception and the contact is in an open state, the current is bypassed by this resistive element film, so that the contact potential can be detected. It becomes possible to detect a short circuit between them and a short circuit between contact points. In addition, even when there is a contact failure at the time of pressure reception, a change in the potential of the contact can be detected by a current bypassing the resistance element film, and a failure of the pressure sensor can be detected.
  The nineteenth aspect of the invention is based on a collection of all the configurations of the first, third and ninth aspects of the invention. “The resistance element film is a resistor for correcting output characteristics such as temperature characteristics or sensitivity characteristics of the pressure-sensitive sensor. The above-mentioned effect is obtained.
  According to a twentieth aspect of the invention, the resistance element film is a resistance for self-diagnosis of the pressure-sensitive sensor in the nineteenth aspect of the invention.
  Since the resistive element film for self-diagnosis is formed on part of the wiring film of the pressure sensor, self-diagnosis of disconnection and short-circuit can be performed from the detection voltage of the contact part regardless of whether it is not receiving pressure or not. It becomes. Since no resistance element is required outside as in the case of the first aspect, the manufacturing is easy, and the device can be reduced in size and cost.
  The invention of claim 21 has the additional matter of claim 4 as an additional matter, and has the above-mentioned effect.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following Example.
(First embodiment)
  The first embodiment isClaims 13, 14, and 16This invention is embodied. This embodiment is a pressure sensitive sensor in which a resistance element film for self-diagnosis is formed as a part of a wiring film. 1, 2, and 3 are a plan view, a cross-sectional view, and a plan view schematically showing a specific embodiment of the present invention. The pressure-sensitive sensor 10 of the present invention has a first resin film 11 and a second resin film 12 facing it. As shown in FIG. 3, a pressure sensitive resistance film 20 is formed on the inner surface of the first resin film 11, and as shown in FIG. 1, the wiring film 13, on the inner surface of the second resin film 12, A resistive element film 30 is formed. As shown in FIG. 2, the first resin film 11 shown in FIG. 3 and the second resin film 12 shown in FIG. 1 are joined with a spacer film 14 interposed therebetween.
[0023]
  The first and second resin films 11 and 12 are made of polyethylene terephthalate (PET) or the like, and the pressure-sensitive resistance film 20 and the resistance element film 30 are made of the same material. For example, carbon particles are made of polyester. These are kneaded using a resin polymer such as polyether or polycarbonate as a binder. The wiring film 13 is made of a metal material having a high conductivity such as silver or copper having a thickness of 10 to 100 μm.
[0024]
  The wiring film 13 made of copper or silver is formed by printing a silver paste using a resin-based polymer as a binder, or is formed into a predetermined shape by an etching technique using a photomask made of a foil and a photocurable resin. Patterned. Alternatively, it may be patterned into a predetermined shape by an electroless plating technique. Further, the pressure sensitive resistance film 20 and the resistance element film 30 can be formed by the same method. In the case of forming by screen printing, the wiring film 13, the pressure sensitive resistance film 20, and the resistance element film 30 may be formed by screen printing to a thickness of 1 to 100 μm and drying at 100 to 200 ° C. after printing. it can. The spacer film 14 is bonded to the first resin film 11 and the second resin film 12 with an adhesive.
[0025]
  The wiring film 13 is formed on the inner surface of the second resin film 12 as shown in FIG. The wiring film 13 is formed to meander in the upper region of the pressure-sensitive resistance film 20. The wiring film 13 existing in this region constitutes a pair of contact surfaces 131 and 132. The pair of contact surfaces 131 and 132 are brought into contact with the pressure-sensitive resistance film 20 at the time of pressure reception, so that the contact surfaces 131 and 132 are electrically connected. That is, the contact surfaces 131 and 132 constitute a contact terminal, and the pressure sensitive resistance film 20 constitutes a movable contact piece. Therefore, the contact portion that receives pressure and performs a switching action is constituted by the contact surfaces 131 and 132 that are part of the wiring film 13 and the pressure-sensitive resistance film 20. In the contact portion, when the pressure is not applied, the spacer film 14 holds a constant gap between them so that the pressure-sensitive resistance film 20 and the contact surfaces 131 and 132 do not contact each other.
[0026]
  The wiring film 13 includes a ground wiring film 133 and a power supply / detection wiring film 134. The power supply / detection wiring film is a wiring film that commonly performs power supply for applying a voltage to the contact portion and detection of the voltage at the contact portion. The resistance element film 30 is formed between the tip of the power supply / detection wiring film 134 and the branch wiring 135 branched from the ground wiring film 133. That is, the resistive element film 30 is arranged in parallel with the contact terminals formed by the pair of contact surfaces 131 and 132 when viewed as an electric circuit.
[0027]
  FIG. 4 shows an equivalent circuit of the pressure-sensitive sensor 10 having the configuration shown in FIG. Rd is the resistance of the resistance element film 30, and Rf is the resistance due to the pressure-sensitive resistance film 20. This resistance value changes with pressure. The terminal of the pressure sensor 10 is connected to the detection device 40 of FIG. The detection device 40 includes a load resistance Ro, a power source Ve, and a CPU 41. The power supply / detection wiring film 134 of the pressure-sensitive sensor 10 is connected to the power source Ve via the load resistance Ro, and the ground wiring film 133 is connected to the ground terminal of the detection device 40.
[0028]
  Next, the self-diagnosis function of the pressure sensor 10 will be described. When the switch S is turned on in a state where no pressure is applied to the contact portion of the pressure sensor 10, the load resistance Ro, the resistance Rd of the resistance element film 30, the ground, and the current flow from the power source Ve. Thereby, the voltage of the detection terminal a of the detection apparatus 40 becomes a value obtained by dividing the voltage Ve by the load resistance Ro and the resistance Rd. If this divided voltage is detected, it is determined that no disconnection has occurred in all the wiring films 13. On the other hand, when the power supply voltage Ve is detected, it is possible to determine that there is a break somewhere in the wiring film 13. On the other hand, in the wiring film 13, when the power supply / detection wiring film 134 and the ground wiring film 133 are short-circuited, the detection voltage at the terminal a is not the divided voltage but the ground potential. It becomes possible to judge a short circuit failure.
[0029]
  In the state where the pressure is applied to the contact portion, if the detected voltage at the terminal a is normal, the divided voltage VH between the load resistance Ro and the resistance Rd of the voltage Ve, the load resistance Ro, and the pressure sensitive resistance film A voltage between the divided value VL and the minimum value of the resistance Rf of 20 is detected. Therefore, if a voltage sufficiently higher than the divided voltage VH is detected, it is a disconnection, and if a voltage sufficiently lower than the divided voltage VL is detected, it can be determined as a short circuit.
[0030]
  In this way, by connecting the resistive element film 30 in parallel between the contacts as part of the wiring film 13 in the pressure-sensitive sensor 10, it is possible to easily and accurately perform self-diagnosis of the pressure-sensitive sensor. . The resistor Rd is not provided in the external detection device 40, but the resistor Rd is formed as a part of the wiring film 13 in the same process as the formation of the pressure-sensitive resistance film 20. Thus, it is possible to achieve downsizing, easy manufacturing, and cost reduction.
[0031]
(Second embodiment)
  The second embodiment is a pressure sensitive sensor in which a plurality of contact portions in the first embodiment are dispersedly arranged. FIG. 5 shows a plan configuration and FIG. 6 shows an equivalent circuit thereof. In each of the contact portions 1, 2, 3, resistors Rd1, Rd2, Rd3 made of the resistive element film 30 are connected in parallel to the respective contacts. The ground wiring film 133 circulates around the three contact portions 1, 2, 3 and is continuous. The power supply / detection wiring film 134 includes power supply / detection wiring films 1341, 1342, and 1343 connected to the contact portions 1, 2, and 3, as shown in FIG. The equivalent circuit is simply configured in parallel with respect to the three contact portions 1, 2, and 3. When only one contact portion is seen, it is the same as that of the first embodiment. Therefore, the self-diagnosis for each contact portion can be carried out by the same method as described in the first embodiment even when a plurality of contact portions are dispersedly arranged. In this embodiment in which the resistance element film is formed as a part of the wiring film inside the pressure sensor 10, the external resistance can be reduced as the number of contact portions increases, so that the effect described in the first embodiment is achieved more greatly. Will be.
[0032]
(Third embodiment)
  Next, a third embodiment will be described. This exampleClaim 17This invention is embodied. The difference from the first embodiment is only the contact structure of the contact portion. Parts having the same functions as those in the first embodiment are given the same reference numerals.
  As shown in FIG. 7, in the contact portion, the wiring film 13 is meandered in the first embodiment, whereas in the present embodiment, the pair of contact surfaces 131 and the contact surfaces 132 are parallel lines. It is formed in a shape. Also in this embodiment, the resistive element film 30 is electrically arranged in parallel with a contact terminal constituted by a pair of contact surfaces 131 and 132. In this embodiment, the same effect as that of the first embodiment can be obtained.
[0033]
(Fourth embodiment)
  In the fourth embodiment, a plurality of contact portions having the structure of the third embodiment are dispersedly arranged as in the second embodiment. Parts having the same functions as those in the above embodiment are given the same reference numerals. FIG. 8 shows a plan view thereof. The equivalent circuit is the same as in FIG. Therefore, this embodiment also has the same effect as the second embodiment.
[0034]
(5th Example)
  The fifth embodiment isClaim 18This invention is embodied. The present embodiment is a so-called opposed contact type pressure-sensitive sensor. 9 is a plan view of the configuration, FIG. 10 is a cross-sectional view of the contact portion, and FIG. 11 is an equivalent circuit thereof. Parts having the same functions as those in the above embodiment are given the same reference numerals. A ground wiring film 133 and a pressure sensitive resistance film 201 are formed on the first resin film 11, and a power supply / detection wiring film 1341, 1342, 1343 and a pressure sensitive resistance film 202 are formed on the second resin film 12. ing. In each contact portion, each pressure-sensitive resistance film 201 is formed on the ground wiring film 133, and each pressure-sensitive resistance film 202 is formed on each power supply / detection wiring film. A contact terminal is constituted by a pair of opposing pressure-sensitive resistance films 201 and 202. Each resistance element film 30 is formed between each of the power supply / detection wiring films 1341, 1342, 1343 and the ground wiring film 133, and is electrically arranged in parallel with the contact terminals of the respective contact portions. Yes. Since the power supply / detection wiring film and the ground wiring film do not exist on the same plane as shown in FIG. 10, the resistive element film 30 is formed on both sides of the power supply / detection wiring film and the ground wiring film like the spacer film 14. Each is connected.
[0035]
  Since the equivalent circuit of such a pressure-sensitive sensor 10 is as shown in FIG. 11, it has exactly the same effect as the above-described embodiment in which a plurality of contact portions are dispersedly arranged.
[0036]
(Sixth embodiment)
  In the sixth embodiment, the resistance element film is a resistance for compensating output characteristics such as temperature compensation or sensitivity compensation. This exampleClaim 7This invention is embodied. Parts having the same functions as those in the above embodiment are given the same reference numerals. As shown in FIG. 12, the structure of the contact portion is the short bar contact method as in the third embodiment, and the contact surfaces 132 and 131 are parallel lines. In this embodiment, the power supply / detection wiring film 134 of the third embodiment is divided into a power supply wiring film 136 and a detection wiring film 137, and the tip of the detection wiring film 137 serves as a contact surface 131 constituting a contact. The contact surface 131 is configured to be supplied with power through the resistance element film 31 and to be applied with a voltage. This resistance element film 31 becomes a resistance for output characteristic compensation.
[0037]
  The equivalent circuit is as shown in FIG. The resistor Rc is a resistor composed of the resistive element film 31, and is fed from the power source Ve to the power supply wiring film 136, the resistor Rc, the contact portion, and the ground wiring film 133. The voltage of the contact surface 131 to which the high voltage is applied at the contact portion is input to the CPU 41 of the detection device 40 via the detection wiring film 137. Since the resistance element film 31 and the pressure sensitive resistance film 20 are made of the same material, the temperature coefficients α of the resistance Rc and the resistance Rf are equal. Therefore, since the detection voltage Vo is a voltage obtained by dividing the power supply voltage Ve by the resistor Rc and the resistor Rf, the detection voltage at the temperature T is expressed by the following equation.
[0038]
[Expression 1]
Vo = {2Rf [1 + α (T−T₀)]} · Ve / {(Rc + 2Rf) [1 + α (T−T₀)]}
    = 2Rf · Ve / (Rc + 2Rf)
  However, T₀Is the temperature defining the primary temperature coefficient α.
[0039]
  Thus, the detection voltage Vo is no longer a function of temperature. Thus, since the temperature compensation resistive element film 31 is provided inside the pressure sensor 10, the configuration of the external detection device 40 becomes extremely simple. Moreover, since the resistive element film 31 is disposed at a position close to the contact portion, the temperatures of the pressure-sensitive resistive film 20 and the resistive element film 31 are equal, and accurate temperature compensation can be performed. Due to such a configuration, as in the above embodiment, the manufacture can be facilitated, and the apparatus can be reduced in size and cost.
[0040]
(Seventh embodiment)
  In the seventh embodiment, a plurality of contact portions are arranged in a distributed manner in the sixth embodiment. This exampleClaim 9This invention is embodied. Parts having the same functions as those in the above embodiment are given the same reference numerals. As shown in FIG. 14, a plurality of contact portions having the configuration of FIG. Power supply wiring films 1361, 1362, and 1363 and detection wiring films 1371, 1372, and 1373 are provided for the contact portions 1, 2, and 3, respectively. A resistor Rc1, a resistor Rc2, and a resistor Rc3 are arranged between the resistor elements 31. An equivalent circuit of the pressure sensor 10 is as shown in FIG. The detection voltages V1, V2, and V3 from the respective contact portions do not vary in temperature as in the sixth embodiment described above. Therefore, accurate temperature compensation can be performed. In addition, since a large number of temperature compensating resistors are formed as part of the wiring film inside the pressure sensor, the configuration of the external device becomes simpler. Accordingly, the same effects as those of the above-described embodiment can be obtained.
[0041]
(Eighth embodiment)
  In the eighth embodiment, the contact structure is the opposite type as in the fifth embodiment.Claim 3This invention is embodied. Parts having the same functions as those in the above embodiment are given the same reference numerals. The difference from the seventh embodiment is that in the seventh embodiment, the power supply wiring film and the detection wiring film are formed on the same resin film. Therefore, it was necessary to wire each of the power supply wiring films. In order to make this power supply wiring film common, in this embodiment, the first resin film 11 is provided with a power supply wiring film 136 that is common to the ground wiring film 133, and the second resin film 12 is provided with detection wiring for each contact portion. Membranes 1371, 1372, and 1373 are provided. Then, as can be understood from FIG. 17 showing the cross section of the portion A in FIG. 16, each resistance element film 32 of each contact portion is composed of a common power supply wiring film 136 and each detection wiring film 1371, 1372, 1373 from both sides. It is arrange | positioned so that it may be pinched | interposed. With such a configuration, the wiring in the pressure-sensitive sensor can be simplified as one common power supply wiring film 136, and the wiring density can be further improved.
[0042]
(Ninth embodiment)
  In the ninth embodiment, a single resistive element film for compensating output characteristics is used. This exampleClaim 10This invention is embodied. In the seventh and eighth embodiments, the temperature compensation resistance element film is provided for each contact portion. However, in this embodiment, as shown in FIG. 18, a common resistive element film 33 is formed for each of the contact portions 1, 2, and 3. The resistance element film 33 is formed between the reference voltage wiring film 138 and the ground wiring film 132. Parts having the same functions as those in the above embodiment are given the same reference numerals. An equivalent circuit of the pressure sensor 10 is as shown in FIG. Since the resistance Rr due to the resistance element film 33 has the same temperature coefficient as the resistance Rf of the pressure-sensitive resistance film 20, the voltage change rate of the reference voltage Vr due to temperature fluctuation is the voltage of the detection voltages V1, V2, and V3 at each contact portion. It becomes equal to the rate of change. Accordingly, if the voltage ratio is set to 2Rf = Rr (2Rf is a value when the standard pressure is applied with the entire resistance value of the pressure-sensitive resistance film 20), the voltage ratios V1 / Vr, V2 / Vr, V3 / Vr are set. Regardless of temperature,TheIt becomes constant. The temperature characteristics are compensated by detecting the pressure received at each contact point by this voltage ratio by the CPU 41 of the detection device 40.
[0043]
(Tenth embodiment)
  This exampleClaims 11 and 12This invention is embodied. That is, the resistance element film that is a resistance for self-diagnosis in the second embodiment and the resistance element film that is a resistance for correcting output characteristics such as temperature characteristics or sensitivity characteristics in the seventh embodiment are simultaneously formed in the wiring film. It is formed as a part of Parts having the same functions as those of the second and seventh embodiments are denoted by the same reference numerals. An equivalent circuit of this pressure-sensitive sensor is shown in FIG. In each of the contact portions 1, 2, 3, resistors Rd1, Rd2, Rd3 made of the resistive element film 30 are connected in parallel to the respective contacts. The ground wiring film 133 circulates around the three contact portions 1, 2, 3 and is continuous. Power supply wiring films 1361, 1362, and 1363 and detection wiring films 1371, 1372, and 1373 are provided for the contact portions 1, 2, and 3, respectively. A resistor Rc1, a resistor Rc2, and a resistor Rc3 are arranged between the resistor elements 31.
[0044]
  Each detected voltage V1, V2, V3 from each contact portion does not vary in temperature as in the seventh embodiment. Therefore, accurate temperature compensation can be performed. In addition, since a large number of temperature compensating resistors are formed as part of the wiring film inside the pressure sensor, the configuration of the external device becomes simpler. Accordingly, the same effects as those of the above-described embodiment can be obtained.
  In addition, self-diagnosis for each contact portion can be performed by the same method as described in the second embodiment.
  In this embodiment in which a resistance element film functioning as a resistance for correcting self-diagnosis and output characteristics is formed as a part of the wiring film inside the pressure-sensitive sensor 10, the external resistance can be reduced as the number of contact portions increases. Thus, the configuration of the external detection device can be simplified, and a greater effect can be achieved.
  If the embodiment is a counter-contact type pressure-sensitive sensor as in the eighth embodiment, the following configuration may be used. In FIG. 16, a resistance element film for self-diagnosis is added in parallel between the contacts at positions closer to the contacts than the resistance element film 32 in each contact portion. Thereby, a resistive element film as a resistance for output characteristic compensation and a resistive element film as a resistance for self-diagnosis can be formed simultaneously. Moreover, in this case, the power supply wiring film can be shared by one. This resistance element film for self-diagnosis is also disposed between two resin films as shown in FIG.
[0045]
  Furthermore, the resistive element film for self-diagnosis of the first to fifth embodiments and the resistive element film for compensating output characteristics of the sixth to ninth embodiments are arbitrarily combined. It may be provided. In this case, it is possible to make arbitrary combinations of the respective embodiments.
[0046]
(Modification)
  In the sixth to ninth embodiments, the compensation of the temperature characteristics has been described. However, the ratio of the detected voltage to the pressure, that is, it can be used as a resistor for sensitivity adjustment. Further, when a plurality of contact portions are provided, it can be used as an adjustment resistor for making the sensitivity to each contact portion uniform.
[Brief description of the drawings]
FIG. 1 is a plan view showing the structure of a pressure-sensitive sensor according to a specific first embodiment of the present invention.
FIG. 2 is a cross-sectional view of the pressure sensor of the first embodiment.
FIG. 3 is a plan view showing a configuration of a first resin film of the pressure sensor according to the first embodiment.
FIG. 4 is an equivalent circuit diagram of the pressure sensor according to the first embodiment.
FIG. 5 is a plan view showing the structure of a pressure-sensitive sensor according to a second specific example of the present invention.
FIG. 6 is an equivalent circuit diagram of a pressure sensitive sensor according to a second embodiment.
FIG. 7 is a plan view showing the structure of a pressure sensor according to a specific third embodiment of the present invention.
FIG. 8 is a plan view showing the structure of a pressure-sensitive sensor according to a specific fourth embodiment of the present invention.
FIG. 9 is a plan view showing the structure of a pressure-sensitive sensor according to a fifth specific example of the present invention.
FIG. 10 is a sectional view of a pressure sensor according to a fifth embodiment.
FIG. 11 is an equivalent circuit diagram of a pressure sensitive sensor according to a fifth embodiment.
FIG. 12 is a plan view showing the structure of a pressure-sensitive sensor according to a sixth specific example of the present invention.
FIG. 13 is an equivalent circuit diagram of a pressure sensor according to a sixth embodiment.
FIG. 14 is a plan view showing the structure of a pressure-sensitive sensor according to a seventh specific example of the present invention.
FIG. 15 is an equivalent circuit diagram of a pressure sensor according to a seventh embodiment.
FIG. 16 is a plan view showing the structure of a pressure-sensitive sensor according to a specific eighth embodiment of the present invention.
FIG. 17 is a cross-sectional view of a pressure sensor according to an eighth embodiment.
FIG. 18 is a plan view showing the structure of a pressure-sensitive sensor according to a specific ninth embodiment of the present invention.
FIG. 19 is an equivalent circuit diagram of a pressure sensitive sensor according to a ninth embodiment.
FIG. 20 is a plan view showing the structure of a pressure sensitive sensor according to a specific tenth embodiment of the present invention.
FIG. 21 is an equivalent circuit diagram of the pressure sensor of the tenth embodiment.
[Brief description of the sign]
1, 2, 3 ... Contact part
10 ... Pressure-sensitive sensor
11 ... 1st resin film
12 ... Second resin film
13 ... Wiring film
20, 201, 202 ... pressure sensitive resistance film
30, 31, 32, 33 ... resistive element film
131, 132 ... contact surface
133 ... Earth wiring film
134: Power supply / detection wiring film
1341, 1342, 1343 ... Power supply / detection wiring film
136, 1361, 1362, 1363 ... power supply wiring film
137, 1371, 1372, 1373... Detection wiring film

Claims

In a pressure sensor having a contact portion formed on the inner surfaces of a pair of upper and lower resin films and closed according to pressure reception, and a wiring film connected to the contact portion,
A resistance element film is formed as a part of the wiring film ,
The pressure-sensitive sensor, wherein the resistance element film is a resistor for correcting an output characteristic such as a temperature characteristic or a sensitivity characteristic of the pressure-sensitive sensor.

The pair of resin films includes a first resin film and a second resin film, and is formed on a pressure-sensitive resistance film formed on an inner surface of the first resin film and an inner surface of the second resin film. The pressure sensor according to claim 1 , wherein the contact portion is formed by a contact surface of the wiring film that is short-circuited by contact with the piezoresistive film.

The pair of resin films includes a first resin film and a second resin film, and the wiring film is formed on the inner surfaces of the first resin film and the second resin film, is continuous with the wiring film, and contacts when receiving pressure. The pressure sensor according to claim 1 , wherein the contact portion is formed by a pair of contact surfaces facing each other.

The pressure sensor according to claim 3 , wherein at least one contact surface of the pair of contact surfaces of the contact portion is formed of a pressure sensitive resistance film.

The pressure sensor according to claim 2 , wherein the contact surface is formed in a meandering manner in a region where the pressure sensitive resistance film is formed.

The pressure-sensitive sensor according to claim 2 , wherein the contact surface is formed in a parallel line shape in a region where the pressure-sensitive resistance film is formed.

The wiring layer is made of a detection wire film for detecting the potential of the feed interconnection film and the contact surface of the power feeding to the front Kise' Sawamen, the resistive element film is inserted in series before Symbol feed line film The pressure-sensitive sensor according to any one of claims 2 to 6, wherein the pressure-sensitive sensor is provided.

The pressure sensor according to claim 7 , wherein the resistance element film is made of the same material as the pressure sensitive resistance film.

In the resin film, a plurality of the contact portions for detecting pressure reception of each portion are provided in a dispersed manner, the power supply wiring film supplies power in parallel to each contact portion, and the detection wiring film is provided for each contact portion. pressure-sensitive sensor according to claim 7 or claim 8, characterized in that it is connected for.

In the resin film, a plurality of the contact portions for detecting the pressure of each portion are provided in a dispersed manner, and only one resistor element film is provided in common for each contact portion. sensitive pressure sensor of any one of claims 2 to 6, characterized in that the detection wiring film is formed for detecting a terminal voltage of.

The pressure-sensitive sensor according to claim 1, further comprising a resistor for self-diagnosis of the pressure-sensitive sensor as another resistive element film.

The pressure-sensitive sensor according to claim 7, wherein a resistor for self-diagnosis is connected in parallel to the contact surface as another resistive element film.

In a pressure sensor having a contact portion formed on the inner surfaces of a pair of upper and lower resin films and closed according to pressure reception, and a wiring film connected to the contact portion,
A resistance element film is formed as a part of the wiring film,
The pair of resin films includes a first resin film and a second resin film, and is formed on a pressure-sensitive resistance film formed on an inner surface of the first resin film and an inner surface of the second resin film. The contact portion is formed by the contact surface of the wiring film that is short-circuited by contact with the piezoresistive film,
The pressure sensor is characterized in that the contact surface is formed to meander in the formation region of the pressure sensitive resistance film.

In a pressure sensor having a contact portion formed on the inner surfaces of a pair of upper and lower resin films and closed according to pressure reception, and a wiring film connected to the contact portion,
A resistance element film is formed as a part of the wiring film,
The pair of resin films includes a first resin film and a second resin film, and is formed on a pressure-sensitive resistance film formed on an inner surface of the first resin film and an inner surface of the second resin film. The contact portion is formed by the contact surface of the wiring film that is short-circuited by contact with the piezoresistive film,
The resistance element film is a resistance for self-diagnosis, and is connected in parallel to the contact surface.

In a pressure sensor having a contact portion formed on the inner surfaces of a pair of upper and lower resin films and closed according to pressure reception, and a wiring film connected to the contact portion,
A resistance element film is formed as a part of the wiring film,
The pair of resin films includes a first resin film and a second resin film, and is formed on a pressure-sensitive resistance film formed on an inner surface of the first resin film and an inner surface of the second resin film. The contact portion is formed by the contact surface of the wiring film that is short-circuited by contact with the piezoresistive film,
In the resin film, a plurality of the contact parts for detecting pressure received at each part are provided in a dispersed manner, and the wiring film is a power supply wiring film that supplies power to the contact surface and a detection wiring film that detects the potential of the contact surface The pressure-sensitive sensor is characterized in that the power supply wiring film supplies power to each contact portion in parallel, and the detection wiring film is connected to each contact portion.

The pressure-sensitive sensor according to claim 13 or 15, wherein the resistance element film is a resistance for self-diagnosis of the pressure-sensitive sensor.

The pressure sensor according to any one of claims 14 to 16, wherein the contact surface is formed in a parallel line shape in a region where the pressure sensitive resistance film is formed.

In a pressure sensor having a contact portion formed on the inner surfaces of a pair of upper and lower resin films and closed according to pressure reception, and a wiring film connected to the contact portion,
A resistance element film is formed as a part of the wiring film,
The pair of resin films includes a first resin film and a second resin film, and the wiring film is formed on the inner surfaces of the first resin film and the second resin film, is continuous with the wiring film, and contacts when receiving pressure. The contact portion is formed by a pair of contact surfaces facing each other,
The resistance element film is a resistance for self-diagnosis, and is connected in parallel to the pair of contact surfaces.

In a pressure sensor having a contact portion formed on the inner surfaces of a pair of upper and lower resin films and closed according to pressure reception, and a wiring film connected to the contact portion,
A resistance element film is formed as a part of the wiring film,
The pair of resin films includes a first resin film and a second resin film, and the wiring film is formed on the inner surfaces of the first resin film and the second resin film, is continuous with the wiring film, and contacts when receiving pressure. The contact portion is formed by a pair of contact surfaces facing each other,
In the resin film, a plurality of the contact portions for detecting pressure reception of each portion are provided in a dispersed manner, the power supply wiring film supplies power in parallel to each contact portion, and the detection wiring film is provided for each contact portion. A pressure-sensitive sensor characterized by being connected to the sensor.

The pressure sensor according to claim 19, wherein the resistance element film is a resistance for self-diagnosis of the pressure sensor.

The pressure sensitive sensor according to any one of claims 19 to 21, wherein at least one of the pair of contact surfaces of the contact portion is formed of a pressure sensitive resistance film.