JP3605899B2

JP3605899B2 - Optical scanner device

Info

Publication number: JP3605899B2
Application number: JP25370195A
Authority: JP
Inventors: 司甲村; 英昭西川; 義則大塚
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1995-09-29
Filing date: 1995-09-29
Publication date: 2004-12-22
Anticipated expiration: 2015-09-29
Also published as: JPH0997305A

Description

【０００１】
【発明の属する技術分野】
本発明は、バーコードリーダ，レーザプリンタ，レーザレーダ等において、レーザ光等の所定の光を走査対象物に対して１次元方向に走査するのに使用される光スキャナ装置に関する。
【０００２】
【従来の技術】
従来より、この種の光スキャナ装置として、例えば特開昭６３−８５７６５号公報に開示されているように、反射ミラーと、振動発生用の平面コイルと、これら各部を両側から支持する捩り振動部とを、水晶板等からなる同一の板材上に形成した光偏向素子を備え、この光偏向素子の平面コイルへの通電により、捩り振動部を捩り振動させてミラーを所定方向に回動させることにより、レーザ光を走査するようにしたものが知られている。
【０００３】
【発明が解決しようとする課題】
しかし、こうした従来の光スキャナ装置では、所謂両持ち梁を形成する一対の捩り振動部により、反射ミラーと平面コイルとを支持し、捩り振動部の振動によりこれら各部が共に回動するように構成されていたため、走査時に捩り振動部にかかる応力が大きく、捩り振動部の幅等をその応力に耐え得るよう大きくする必要があった。そして、このように捩り振動部の幅等を大きくすると、振動の幅，延いては走査角度を大きくすることができなくなるため、ミラー部を大きな走査角度で回動させるためには、必然的に捩り振動部の長さを長くしなければならず、装置の大型化を招くという問題がある。
【０００４】
本発明は、こうした問題に鑑みなされたもので、反射ミラーを一対の捩り振動部にて支持し、捩り振動部の捩り振動により反射ミラーを所定の走査方向に回動させる光スキャナ装置において、装置の大型化を招くことなく、走査角度を大きくできるようにすることを目的とする。
【０００５】
【課題を解決するための手段】
かかる目的を達成するために、本発明の光スキャナ装置では、一対の捩り振動部により、光を反射する反射面が形成されるミラー部を、その両側から直接支持すると共に、各捩り振動部を、ミラー部の回転軸を中心に矩形波状に変化する折り返し形状に形成し、更に、捩り振動部を振動させてミラー部を回動させる加振手段は、捩り振動部と外枠とを連結する一方の連結部に設けるようにしている。
【０００６】
このため、本発明によれば、捩り振動部により加振手段を支持する必要がなく、捩り振動部にはミラー部の回動に伴う応力のみが加わることから、従来装置のようにミラー部の回動に加えて加振手段の回動に伴う応力に耐え得るように捩り振動部の幅を大きくする必要はなく、従って、所望の走査角度を得るために捩り振動部を長くする必要はない。また、本発明では、この捩り振動部を折り返し形状にしているため、捩り振動部の実質的な長さを確保しながら、捩り振動部全体の長さを短くできる。従って、本発明によれば、光偏向素子において捩り振動部が占める面積を小さくすることができ、光スキャナ装置の小型化を図ることができる。
【０００７】
但し、各捩り振動部の折り返し形状を、単に直線部分からなる矩形波状にすると、各捩り振動部の折り返し部分の角部（特に内側角部）に応力が集中し易くなる。
そこで、請求項１に記載の光スキャナ装置では、各捩り振動部の折り返し形状を、矩形波の角部に丸みをつけた正弦波状にした。このように各捩り振動部を形成すれば、捩り振動部の角部にかかる応力を低減して、その強度を向上できる。
その他、請求項２に記載のように、各捩り振動部を、ミラー部の回転軸を中心に矩形波状に変化する折り返し形状であって、ミラー部の回転軸と直交する部分の幅に対して回転軸に平行な部分の幅が大きくなるように形成してもよい。このように捩り振動部を形成しても、捩り振動部の角部にかかる応力を低減して、その強度を向上できる。
【０００８】
また、捩り振動部は、折り返し形状になっているため、スキャナ装置の走査角度を確保しつつその小型化を図る上では極めて有効な手段となるが、こうした折り返し形状では外力を受けると変形し易いことから、その取り扱いに充分注意しなければならない。
【０００９】
そこで、光偏向素子には、請求項３に記載のように、各捩り振動部とミラー部とを囲む内枠を設け、この内枠にて各捩り振動部と連結部との結合部分を連結するとよい。このようにすれば、各捩り振動部を内枠によって保護することができ、取り扱いも容易に行えるようになるので、より望ましい。
【００１０】
また、このように光偏向素子に内枠を設けた場合、ミラー部の回転軸上の位置にて、捩り振動部の両端をミラー部及び内枠に夫々結合するようにしてもよいが、この場合、捩り振動部の両端をミラー部の回転軸上の位置まで折り返し、更にその位置にてミラー部及び内枠に結合するようにしなければならず、捩り振動部が回転軸方向に不必要に長くなってしまうことがある。
【００１１】
そこで、このように捩り振動部が不必要に長くなるような場合には、請求項４に記載のように、各捩り振動部の両端を、夫々、ミラー部と内枠との対向部の内の互いに対角となる位置に結合するようにしてもよい。つまり、このような構成は、光偏向素子に内枠を設けた場合に光スキャナ装置の小型化を図る上で極めて有効な手段となり得る。
【００１２】
一方、連結部に設ける加振手段は、従来装置のように通電により電磁力を発生するコイルを使用することもできるが、この場合、コイルを固定磁界内に配置しなければならず、固定磁界形成用の永久磁石等を別途設けなければならない。
そこで、加振手段としては、請求項５に記載のように、連結部に接着した板状の圧電素子からなる圧電ユニモルフ又は圧電バイモルフにて構成することが望ましい。つまりこのように加振手段を圧電ユニモルフ又は圧電バイモルフにて構成すれば、加振手段への印加電圧を変化させるだけで捩り振動部を所望周波数で捩り振動させることができることから、光スキャナ装置をより小型化することが可能になる。
【００１３】
なお、このように加振手段を圧電ユニモルフ又は圧電バイモルフにて構成する場合には、請求項５に記載のように、連結部を、外枠の内側から回転軸に向かって突出された一対の装着部と、その両端を接続すると共に略中心位置にて捩り振動部が結合される接続部とから構成し、しかも板状の圧電素子が接着される一対の装着部は、圧電素子の電極となり得るように、少なくともその表面が導電性を有するようにする必要があるが、このためには、ミラー部，捩り振動部，連結部等を構成する板材自体に、導電性の金属板を用いるようにしてもよく、或は、板材には非導電性の板状部材を用い、上記各部形成後、板状部材全体又は装着部のみに導電性被膜を形成するようにしてもよい。
【００１４】
また、このように圧電ユニモルフ又は圧電バイモルフにて捩り振動部を振動させるには、圧電ユニモルフ又は圧電バイモルフの外枠側端部を固定して、各圧電ユニモルフ又は各圧電バイモルフを互いに異なる方向に変位させるための駆動電圧を印加する必要があるが、この場合、請求項６に記載のように、圧電ユニモルフ又は圧電バイモルフの外枠側端部を、電圧印加用の配線をパターニングした基板と、導電性の金属板とにより挟持するようにすればよい。
【００１５】
つまり、このようにすれば、圧電ユニモルフ又は圧電バイモルフを基板と金属板とにより固定できると共に、金属板側を共通電極としてグランドライン等に接地した状態で、基板に形成された電圧印加用の配線を介して各圧電ユニモルフ又は各圧電バイモルフに駆動電圧を印加することにより、各圧電ユニモルフ又は各圧電バイモルフを変位させることができ、加振手段を固定する固定手段及びその駆動系を、極めて簡単な構成にて実現できる。
【００１６】
【発明の実施の形態】
以下に本発明の実施例を図面と共に説明する。
なお、以下の説明において、図１は、本発明が適用された実施例の光スキャナ装置全体の構成を表わし、（ａ）はその裏面図、（ｂ）はその表面図を表わす。また図２は、本実施例の光スキャナ装置１の光偏向素子を構成するプレートの形状を表わし、（ａ）はその全体図、（ｂ）は捩り振動部としてのバネ部の拡大図である。
【００１７】
図１に示す如く、光スキャナ装置１は、薄板バネ材にて形成された光偏向素子としてのプレート３と、プレート３の表面側の中央に設置された反射ミラー５と、同じくプレート３の表面側の四隅に配置された板状の圧電素子６ａ，７ａ，８ａ，９ａからなる圧電ユニモルフ６，７，８，９と、これら各圧電ユニモルフ６〜９の外側端部をプレート３の表面側から覆うように配設された中空の基板１１と、該基板１１との間で圧電ユニモルフ６〜９及びプレート３を挟持する導電性の金属板からなる中空の押え板１３とを備えている。
【００１８】
プレート３は、薄板状（厚さ０．０５ｍｍ程度）の導電性金属からなるバネ材料（ベリリウム銅，バネ用ステンレス等）を、エッチング、放電加工等を利用して打ち抜くことにより、図２（ａ）に示すように形成されている。
即ち、プレート３は、押え板１３と略同じ大きさ（外形：２０ｍｍ×２０ｍｍ程度）の外枠３１と、外枠３１の略中心に位置し、表面に反射ミラー５が設けられる略正方形のミラー部３３と、ミラー部３３の対角部から上下方向に延出され、ミラー部３３の左右幅方向の中心を通る中心軸（回転軸）Ｚを中心に矩形波状に変化する折り返し形状をした、捩り振動部としての一対のバネ部３５，３７（図１，２においてハッチングを付した部分）と、バネ部３５，３７の外側端部に各々結合され、バネ部３５，３７及びミラー部３３を囲む内枠３９と、外枠３１の中空部左右の上下両端部からミラー部３３の回転軸Ｚに向かって延出された圧電ユニモルフ６〜９形成用の装着部４６，４７，４８，４９と、これら４個の装着部４６〜４９の内、互いに対向する装着部４６，４７及び４８，４９と、内枠３９の上下両端部とを、夫々、ミラー部３３の回転軸Ｚ上で連結するＴ字状の接続部４１，４３とから構成されている。
【００１９】
ここで、バネ部３５，３７は、ミラー部３３を両側から支持して、自らの捩り振動によりミラー部３３を回転軸Ｚを中心に回動させるものである。このため、振動時には、図２（ｂ）に示すＣのような折り返しの内側角部（コーナ）において応力が集中し易い。そこで、各コーナには、若干丸み（所謂Ｒ）が付けられるが、本実施例では、集中応力をより低減するために、回転軸Ｚと直交する部分の幅Ａに対して、回転軸Ｚに平行な部分の幅Ｂが大きくされている。これは、矩形波状に形成したバネ部３５，３７においては、回転軸Ｚに平行な矩形波の頂点部分が大きく捩れるためであり、本実施例では、このように構成することにより、バネ部３５，３７の強度を高めているのである。
【００２０】
また、各バネ部３５，３７は、ミラー部３３及び内枠３９の対向面上にて互いに対角となる位置に連結されている。これは、各バネ部３５，３７に不要な折り返しを設けることなく、ミラー部３３と内枠３９とを連結できるようにするためであり、こうすることにより、プレート３が上下方向に大きくなるのを防止している。
【００２１】
また本実施例では、ミラー部３３に設けられる反射ミラー５に、アルミ蒸着で高反射コ一ティングを施したシリコン製のミラーが使用され、ミラー部３３には、反射ミラー５が接着剤等を用いて接着される。
次に、上記４個の圧電ユニモルフ６〜９は、装着部４６〜４９に板状の圧電素子６ａ〜９ａを接着することにより形成されており、その内、プレート３上方の装着部４６，４７に形成される圧電ユニモルフ６，７は、接続部４１に捩り振動のための駆動力を与えてバネ部３５を捩り振動させる、加振手段としての駆動用圧電ユニモルフとして使用され、プレート３下方の装着部４８，４９に形成される圧電ユニモルフ８，９は、バネ部３７の捩り振動を接続部４３を介して検出するセンサ用圧電ユニモルフとして使用される。
【００２２】
つまり、本実施例では、プレート３が導電性金属からなるバネ材料にて形成されているため、各装着部４６〜４９に板状の圧電素子６ａ〜９ａを接着すれば、プレート３がこれら各圧電素子６ａ〜９ａの共通電極となる。そして、図３（ａ）に示すように、各圧電素子６ａ〜９ａの装着部４６〜４９とは反対側面に電極２６〜２９を設けて、この電極２６〜２９とプレート３との間に電圧を印加すれば、圧電ユニモルフ６〜９は、図３（ｂ）に示す如く所定方向に変位し、逆にその電極２６〜２９とプレート３との間に発生した電圧を検出すれば、圧電ユニモルフ６〜９の変位量を検出できる。
【００２３】
そこで、本実施例では、各圧電素子６ａ〜９ａの両面に電極形成用の導電材（例えば銀ペースト）を塗布すると共に、駆動用圧電ユニモルフ６，７及びセンサ用圧電ユニモルフ８，９を夫々構成する一対の圧電素子６ａ，７ａ及び８ａ，９ａの分極方向が、図３（ａ）に矢印で示すように、装着部４６〜４９に対して直交し且つ互いに逆向きとなるように、各圧電素子６ａ〜９ａを装着部４６〜４９に接着し、更に、図１（ａ）に示す如く、基板１１の各圧電素子６ａ〜９ａとの対応位置に、電圧印加用の電極２６〜２９となる電極パターンを施し、基板１１と押え板１３とをねじ１３ａ〜１３ｄにて締め付けることにより、基板１１と押え板１３とで各圧電ユニモルフ６〜９の外側端部を挟持させている。
【００２４】
従って、本実施例の光スキャナ装置１においては、図１（ａ）に示す如く、ねじ１３ｄに通したアース端子２５に、接地用のリード線２５ａを半田付け等にて接続し、基板１１に形成された電極２６，２７に、駆動電圧印加用のリード線２６ａ，２７ａを半田付け等にて接続し、このリード線２６ａ，２７ａを介して、各電極２６，２７と共通電極となる押え板１３（延いてはプレート３）との間に駆動用の高電圧を印加すれば、図３（ｂ）に矢印で示す如く、駆動用圧電ユニモルフ６，７を、その固定部を中心に互いに逆方向に変位させて、接続部４１の回転軸Ｚ回りにトルクを発生させることができる。このため、駆動用電圧を交流にすれば、接続部４１の回転軸Ｚ回りに振動トルクを発生させて、バネ部３５，延いては反射ミラー５を、回転軸Ｚを中心に振動させることができる。
【００２５】
また、図１（ａ）に示す如く、基板１１に形成された電極２８，２９に、電圧検出用のリード線２８ａ，２９ａを半田付け等により接続し、このリード線２８ａ，２９ａを介して、各電極２８，２９と共通電極となる押え板１３との間に発生した電圧を検出すれば、バネ部３７，接続部４３を介して反射ミラー５側より伝達される捩り振動を検出できる。
【００２６】
なお、基板１１は、光スキャナ装置１全体を保持するものであるため、これには、例えばガラスエポキシ樹脂のような硬質の絶縁体基板が使用される。また、図１，図２から明らかな如く、プレート３において、接続部４１，４３は、装着部４６〜４９の幅より細くなっているが、これは、接続部４１，４３を変形（換言すれば伸縮）し易くするためである。つまり、こうすることにより、駆動用圧電ユニモルフ６，７からの駆動力を効率よくバネ部３５に伝達でき、また、センサ用圧電ユニモルフ８，９に、バネ部３７の振動を効率よく伝達できるようにしているのである。
【００２７】
次に図４は、本実施例の光スキャナ装置１を実際に動作させる駆動回路５０の構成を表わす。なお、この駆動回路は、光スキャナ装置１を、その共振周波数にて振動させる所謂自励発振回路である。
図４に示す如く、リード線２８ａ，２９ａにて取り出したセンサ用圧電ユニモルフ８，９からの検出信号（電圧）は、共通の信号線５１にて合成されて駆動回路５０まで導かれる。そして、駆動回路５０内では、その合成された検出信号が２系統に分岐される。
【００２８】
この分岐された検出信号の内、一方は、増幅器５３，整流回路５５，及び平滑回路５７を通過することにより、光スキャナ装置１の振動波形の振幅に応じた直流電圧に変換される。そして、この直流電圧は、差動増幅器５９に入力され、差動増幅器５９において、基準電圧発生源６１から出力される基準電圧との差分に応じた直流電圧に変換される。また上記分岐された検出信号のもう一方は、増幅器６３，位相シフタ６５，ローパスフィルタ６７，及び増幅器６９を通過することにより、高調波成分が除去され、しかも当該駆動回路５０により光スキャナ装置１の実際の振動と位相同期した駆動信号を生成するための振動信号に変換される。
【００２９】
そして、この振動信号と差動増幅器５９からの出力信号（直流電圧）とは、掛け算器７１に入力されて、これら各信号の積に対応した信号に変換される。またこの信号は、更に、増幅器７３を介して、変圧器７５に入力され、変圧器７５において圧電ユニモルフ６，７を駆動可能な電圧（交流３５Ｖ程度）にまで昇圧される。そして、この昇圧された電圧信号（交流）は、信号線７７を介して、駆動用圧電ユニモルフ６，７のリード線２６ａ，２７ａにまで導かれ、駆動信号として、各圧電ユニモルフ６，７に印加される。
【００３０】
この結果、光スキャナ装置１は、自己の共振周波数にて自励振動すると共に、その走査角度は基準電圧にて一定の走査角度に規定されることになる。そして、信号線５１に端子７９を接続し、この端子７９からセンサ用圧電ユニモルフ８，９からの検出信号を取り出すようにすれば、光スキャナ装置１の振動状態，延いては反射ミラー５の走査位置をモニタでき、例えば、光スキャナ装置１をバーコードリーダに用いる場合には、バーコード読取時のデコードタイミングの検出等に利用できる。
【００３１】
なお、このように駆動回路５０を自励発振回路としたのは、光スキャナ装置１は共振型であり、その共振周波数は雰囲気温度の変化等により変化するためである。つまり、光スキャナ装置１を予め設定した共振周波数の駆動信号にて駆動するようにすると、周囲の環境変化によってその駆動信号の周波数が光スキャナ装置１の共振周波数とずれてしまい、光スキャナ装置１を良好に駆動できないことから、本実施例では、駆動回路５０を自励発振回路とすることにより、駆動信号を光スキャナ装置１の共振周波数の変化に追従させて、光スキャナ装置１を常に共振周波数にて振動させることができるようにしているのである。
【００３２】
以上説明したように、本実施例の光スキャナ装置１では、光偏向素子を構成するプレート３において、反射ミラー５を形成するミラー部３３の両側に、捩り振動部としてのバネ部３５，３７を形成すると共に、バネ部３５，３７を矩形波状に形成し、更に、バネ部３５と外枠３１とを連結する連結部の一部を構成する装着部４７，４６に圧電ユニモルフ６，７を形成することにより加振手段を構成している。
【００３３】
このため、本実施例によれば、従来装置のように、バネ部３５，３７により振動発生用の加振手段（コイル）を支持させる必要がなく、バネ部３５，３７を小さくできる。また特に本実施例では、バネ部３５，３７を矩形波状に形成しているので、バネ部３５，３７の実質的な長さを確保したまま、バネ部３５，３７の全体の長さを短くできる。従って本実施例によれば、走査角度を確保しつつ、プレート３，延いては光スキャナ装置１の小型化を図ることができる。
【００３４】
またバネ部３５，３７は、回転軸Ｚと直交する部分の幅Ａに対して、回転軸Ｚに平行な部分の幅Ｂが大きくされているため、バネ部３５，３７の強度を高めることができ、しかも、バネ部３５，３７は、ミラー部３３及び内枠３９の対向面上にて互いに対角となる位置に連結されているため、バネ部３５，３７に不要な折り返しを設けることなく、ミラー部３３と内枠３９とを連結できる。従って、本実施例によれば、このような構成からも、バネ部３５，３７の強度及び振動特性を確保しつつバネ部３５，３７を小さくでき、プレート３，延いては光スキャナ装置１を小型化できる。
【００３５】
またバネ部３５，３７は、矩形波状に形成されているので、外力を受けると変形し易いが、本実施例では、プレート３全体を外枠３１にて囲み、更に、バネ部３５，３７及びミラー部３３については、内枠３９で囲むようにしているので、光スキャナ装置１の組立時等に、外力によりプレート３自体が座屈したり、バネ部３５，３７が変形したりするのを防止できる。従って、組立時等のプレート３の取り扱いを容易に行うことができ、作業性を向上できる。
【００３６】
また更に、本実施例では、加振手段として、プレート３の装着部４７，４６に形成した圧電ユニモルフ６，７を用いるため、コイルを用いた従来装置のように別途振動発生用の部材を設ける必要がなく、装置構成を簡素化し、小型化を図ることができる。そして、特に、本実施例では、プレート３に、加振手段を構成する駆動用圧電ユニモルフ６，７だけでなく、光スキャナ装置１の振動状態を検出する検出手段としてのセンサ用圧電ユニモルフ８，９を設けているため、上記のように駆動回路に自励発振回路を用いることにより、光スキャナ装置１を自励振動させることができるだけでなく、光スキャナ装置１の振動状態をモニタして、その走査位置や動作異常等を検出することもできる。
【００３７】
以上、本発明の一実施例について説明したが、本発明は、上記実施例に限定されるものではなく、種々の態様をとることができる。
例えば、上記実施例では、バネ部３５，３７を矩形波状の折り返し形状にしたが、図５（ａ）に示す如く、矩形波の角部全体に丸みをつけて正弦波状（図では上記実施例と同様、折り返しが２箇所であるため、Ｓ字状になっている）の折り返し形状としてもよい。そしてこの場合、バネ部３５，３７の折り返し部分で各コーナにかかる応力をより低減でき、バネ部３５，３７の強度をより高めることができる。
【００３８】
また、上記実施例においては、内枠３９が、バネ部３５，３７の補強用として設けられているが、取り扱い上特に問題がなければ、図５（ｂ）に示すように内枠３９を取り外し、バネ部３５，３７を直接、接続部４１，４３に連結するようにしてもよい。なおこの場合、ミラー部３３を、その中心軸を回転軸Ｚとして回転させるために、バネ部３５，３７のミラー部３３及び接続部４１，４３への連結位置は、ミラー部３３の中心軸（つまり回転軸）上の位置にする必要はある。
【００３９】
一方、上記実施例においては、基板１１に、各圧電ユニモルフ６〜９に対する駆動電圧印加或は電圧検出用の電極２６〜２９を形成し、これにリード線２６ａ〜２９ａを接続することにより、これら各リード線２６ａ〜２９ａを用いて各圧電ユニモルフ６〜９と駆動回路５０とを接続するように構成したが、図６（ａ）に示す如く、電極２６〜２９が形成される基板１１の裏面に、上記各リード線２５ａ〜２９ａに対応した配線パターン２５ａ′〜２９ａ′及びアース端子２５に対応した電極パターン２５′を形成すると共に、基板１１の下方に、各配線パターン２５ａ′〜２９ａ′への接続端子となる電極パターン２５ｂ〜２９ｂを集中させ、基板１１の表面には、図６（ｂ）に示す如く、アース端子２５としての電極パターン２５′に接続された電極パターン２５″を形成することにより、圧電ユニモルフ６〜９と駆動回路５０との接続を、基板１１の下方に集中させた各電極パターン２５ｂ〜２９ｂを介して行うようにしてもよい。
【００４０】
つまり、このように基板１１を上記各リード線２５ａ〜２９ａをプリント配線にて形成したプリント基板として構成した場合、図７（ａ），（ｂ）に示すように、基板１１と押え板１３との間にプレート３を挟み、アース端子２５となる電極パターン２５′，２５″を形成した部分を含む複数箇所（図では２箇所）にて、基板１１側から導電性のねじ１１ａ，１１ｂを通して、基板１１と押え板１３とを締付固定すれば、基板１１の下方に集中させた各電極パターン２６ｂ〜２９ｂと各圧電ユニモルフ６〜９の表面側とを接続できると共に、接地用の電極パターン２５ｂと各圧電ユニモルフ６〜９の共通端子となる押え板１３とを、ねじ１１ａ，電極パターン２５″，２５′，配線パターン２５ａ′を介して接続できる。
【００４１】
そして、この場合、例えば、図７（ｂ）に示すように、基板１１の下方の表面側に、各電極パターン２５ｂ〜２９ｂに接続された端子８５〜８９を有するコネクタ８０を設け、図８に示すように、このコネクタ８０を、駆動回路５０が形成されたプリント基板９１側に固定したコネクタ９０に接続するようにすれば、光スキャナ装置１と駆動回路５０との接続を、リード線を用いることなく簡単に行うことができ、製造時の工数を低減することができると共に、配線の信頼性を高めることができる。
【００４２】
なおこの場合、基板１１にコネクタ８０を設けず、駆動回路５０が形成されたプリント基板９１或は光スキャナ装置１の任意の取付位置に設けたコネクタに、基板１１の電極パターン２５ｂ〜２９ｂ側を直接差込み、そのコネクタを介して駆動回路５０と各電極パターン２５ｂ〜２９ｂとを接続するようにしてもよい。
【００４３】
また次に、上記実施例では、光偏向素子を構成するプレート３を、導電性金属からなるバネ材料にて形成したが、このバネ材料については、シリコン等の半導体材料を用いることもできる。そしてこのようにすれば、プレート上に駆動回路を形成することも可能になり、駆動回路を含めて光スキャナ装置全体をより小型化できる。またこの場合、エッチングを利用することにより、プレート３の大量生産を図ることができ、その製造コストも低減できる。但し、この場合は、圧電ユニモルフ６〜９を形成する装着部４６〜４９については、導電性の金属（例えば銀ペースト等）により被膜する必要はある。
【００４４】
また更に、上記実施例では、プレート３のミラー部３３に、シリコンからなる反射ミラー５を設けるものとして説明したが、この反射ミラー５としては、ガラスや樹脂等に鏡面加工を施したものを使用してもよい。また、ミラー部３３自体に鏡面加工を施し、その上に、直接、アルミ蒸着等で高反射コーティングを施すことにより、反射ミラーを形成してもよい。
【００４５】
また、上記実施例では、加振手段及び振動検出用の検出手段として、プレート３の装着部４６〜４９の片面に圧電素子６ａ〜９ａを接着することにより形成される圧電ユニモルフ６〜９を用いるものとして説明したが、これら各手段には、例えば、装着部４６〜４９の両面に圧電素子を接着することにより形成可能な圧電バイモルフを用いるようにしてもよい。なお、この場合、各圧電素子の分極方向は、上記実施例と同様にすればよい。
【図面の簡単な説明】
【図１】実施例の光スキャナ装置全体の構成を表わす概略構成図であり、（ａ）はその裏面図、（ｂ）はその表面図である。
【図２】実施例の光スキャナ装置のプレートの形状を説明する説明図であり、（ａ）はその全体図、（ｂ）はバネ部の拡大図である。
【図３】実施例の圧電ユニモルフの構成（ａ）及びその動作（ｂ）を説明する説明図である。
【図４】実施例の駆動回路の構成を表わすブロック図である。
【図５】光偏向素子を構成するプレートの他の構成例を表わす説明図である。
【図６】プリント配線を施した基板の構成例を表わし、（ａ）はその裏面図、（ｂ）はその表面図である。
【図７】図６の基板を用いた光スキャナ装置全体の構成を表わす概略構成図であり、（ａ）はその裏面図、（ｂ）はその表面図である。
【図８】図７に示した光スキャナ装置と駆動回路とをコネクタを介して接続した場合の説明図である。
【符号の説明】
１…光スキャナ装置３…プレート（光偏向素子）５…反射ミラー
６，７…圧電ユニモルフ（駆動用）８，９…圧電ユニモルフ（センサ用）６ａ〜９ａ…圧電素子１１…基板１３…押え板２５…アース端子２６〜２９…電極３１…外枠３３…ミラー部３５，３７…バネ部
３９…内枠４１，４３…接続部４６〜４９…装着部
５０…駆動回路８０…コネクタ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical scanner device used in a barcode reader, a laser printer, a laser radar, and the like to scan a scanning target object in a one-dimensional direction with predetermined light such as laser light.
[0002]
[Prior art]
Conventionally, as this type of optical scanner device, as disclosed in, for example, Japanese Patent Application Laid-Open No. 63-85765, a reflecting mirror, a planar coil for generating vibration, and a torsional vibrating portion for supporting these components from both sides. And an optical deflecting element formed on the same plate made of a quartz plate or the like, and by energizing a plane coil of the optical deflecting element, the torsional vibrator is torsional vibrated to rotate the mirror in a predetermined direction. There is known an apparatus which scans a laser beam.
[0003]
[Problems to be solved by the invention]
However, in such a conventional optical scanner device, a pair of torsional vibrating portions forming a so-called doubly supported beam supports the reflecting mirror and the planar coil, and these components are rotated together by the vibration of the torsional vibrating portion. Therefore, the stress applied to the torsional vibrator during scanning is large, and it is necessary to increase the width of the torsional vibrator so as to withstand the stress. If the width of the torsional vibrating portion is increased in this manner, the width of the vibration and, consequently, the scanning angle cannot be increased. Therefore, in order to rotate the mirror portion at a large scanning angle, it is inevitable. There is a problem that the length of the torsional vibrating portion must be increased, which leads to an increase in the size of the device.
[0004]
The present invention has been made in view of such a problem, and an optical scanner device that supports a reflecting mirror with a pair of torsional vibrating units and rotates the reflecting mirror in a predetermined scanning direction by torsional vibration of the torsional vibrating unit is disclosed. It is an object of the present invention to increase the scanning angle without increasing the size of the image.
[0005]
[Means for Solving the Problems]
To achieve this purpose,The present inventionIn the optical scanner device, a mirror portion on which a reflecting surface for reflecting light is formed by a pair of torsional vibrating portions is directly supported from both sides thereof, and each torsional vibrating portion is rectangular with respect to the rotation axis of the mirror portion. Exciting means which is formed in a folded shape that changes in a wavy manner, and furthermore, vibrates the torsional vibrating portion to rotate the mirror portion is provided at one connecting portion that connects the torsional vibrating portion and the outer frame. .
[0006]
For this reason, according to the present invention, there is no need to support the vibrating means by the torsional vibrating portion, and only the stress accompanying the rotation of the mirror portion is applied to the torsional vibrating portion. It is not necessary to increase the width of the torsional vibrator to withstand the stress caused by the rotation of the vibrating means in addition to the rotation, and therefore it is not necessary to lengthen the torsional vibrator to obtain a desired scanning angle. . Further, in the present invention, since the torsional vibrating portion has a folded shape, it is possible to shorten the entire length of the torsional vibrating portion while securing the substantial length of the torsional vibrating portion. Therefore, according to the present invention, the area occupied by the torsional vibrating portion in the light deflecting element can be reduced, and the size of the optical scanner device can be reduced.
[0007]
However, Folded shape of each torsional vibrating partTo, Just a rectangular wave consisting of straight linesThenIn addition, stress tends to concentrate on the corners (particularly, inner corners) of the folded portions of each torsional vibrating portion.
Therefore, the claim1Described inIn the optical scanner device, the folded shape of each torsional vibrating part isSine wave with rounded corners of square wave. By forming each torsional vibrating portion in this way, the stress applied to the corners of the torsional vibrating portion can be reduced, and the strength thereof can be improved.
Other, Claims2As described inEach torsional vibrating part has a folded shape that changes in a rectangular wave shape around the rotation axis of the mirror part,Formed so that the width of the part parallel to the rotation axis is larger than the width of the part orthogonal to the rotation axis of the mirror partMay be. Even if the torsional vibration part is formed in this way,The stress applied to the corners of the torsional vibrator can be reduced and its strength can be improved.
[0008]
Further, since the torsional vibrating portion has a folded shape, it is an extremely effective means for reducing the size of the scanner device while securing the scanning angle of the scanner device. However, such a folded shape is easily deformed by receiving an external force. Therefore, care must be taken when handling them.
[0009]
Therefore,The light deflecting element may include:As described in the above, an inner frame surrounding each torsional vibrating part and the mirror part is provided, and the connecting part of each torsional vibrating part and the connecting part is connected by this inner frame.Good. thisThis is more preferable because each torsional vibrating portion can be protected by the inner frame, and the handling can be easily performed.
[0010]
Further, when the inner frame is provided in the light deflecting element as described above, both ends of the torsional vibrating unit may be respectively coupled to the mirror unit and the inner frame at positions on the rotation axis of the mirror unit. In this case, both ends of the torsional vibrating part must be folded back to a position on the rotation axis of the mirror part, and further coupled to the mirror part and the inner frame at that position. May be longer.
[0011]
Therefore, when the torsional vibrating part is unnecessarily long like this,Claim 4As described in above, both ends of each torsional vibrating section may be respectively coupled to diagonal positions in opposing sections of the mirror section and the inner frame. That is, such a configuration can be an extremely effective means for reducing the size of the optical scanner device when the inner frame is provided in the light deflecting element.
[0012]
On the other hand, as the vibration means provided in the connecting portion, a coil which generates an electromagnetic force by energization as in the conventional device can be used, but in this case, the coil must be arranged in a fixed magnetic field, A permanent magnet or the like for forming must be provided separately.
Therefore, as vibration means,Claim 5As described in the above, it is desirable that the piezoelectric element is constituted by a piezoelectric unimorph or a piezoelectric bimorph composed of a plate-like piezoelectric element adhered to the connecting portion. That is, if the vibrating means is constituted by a piezoelectric unimorph or a piezoelectric bimorph in this way, the torsional vibrating portion can be torsional vibrated at a desired frequency only by changing the voltage applied to the vibrating means. It is possible to further reduce the size.
[0013]
When the vibrating means is constituted by a piezoelectric unimorph or a piezoelectric bimorph,Claim 5As described in, the connecting portion, a pair of mounting portions protruding from the inside of the outer frame toward the rotation axis, and a connecting portion that connects both ends thereof and a torsional vibrating portion is coupled at substantially the center position And a pair of mounting portions to which the plate-shaped piezoelectric element is adhered, so that at least the surface thereof needs to have conductivity so that it can be an electrode of the piezoelectric element. A conductive metal plate may be used for the plate material itself constituting the mirror portion, the torsional vibrating portion, the connecting portion, or the like. Alternatively, a non-conductive plate member may be used for the plate material and Alternatively, a conductive coating may be formed on the entire plate member or only on the mounting portion.
[0014]
Further, in order to vibrate the torsional vibrating portion with the piezoelectric unimorph or the piezoelectric bimorph, the outer frame side end of the piezoelectric unimorph or the piezoelectric bimorph is fixed, and each piezoelectric unimorph or each piezoelectric bimorph is displaced in a different direction. It is necessary to apply a drive voltage for causingClaim 6As described in the above, the outer frame side end of the piezoelectric unimorph or the piezoelectric bimorph may be sandwiched between the substrate on which the wiring for voltage application is patterned and the conductive metal plate.
[0015]
That is, according to this configuration, the piezoelectric unimorph or the piezoelectric bimorph can be fixed by the substrate and the metal plate, and the voltage application wiring formed on the substrate can be formed in a state where the metal plate side is grounded to a ground line or the like as a common electrode. By applying a drive voltage to each piezoelectric unimorph or each piezoelectric bimorph via the above, each piezoelectric unimorph or each piezoelectric bimorph can be displaced, and the fixing means for fixing the vibration means and the driving system thereof are extremely simple. It can be realized by the configuration.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following description, FIG. 1 shows the overall configuration of an optical scanner device according to an embodiment to which the present invention is applied, (a) showing a rear view, and (b) showing a front view. FIGS. 2A and 2B show the shape of a plate constituting an optical deflecting element of the optical scanner device 1 of the present embodiment, wherein FIG. 2A is an overall view and FIG. 2B is an enlarged view of a spring portion as a torsional vibrating portion. .
[0017]
As shown in FIG. 1, the optical scanner device 1 includes a plate 3 as a light deflecting element formed of a thin leaf spring material, a reflection mirror 5 installed at the center on the front side of the plate 3, and a surface of the plate 3. Piezoelectric unimorphs 6, 7, 8, 9 comprising plate-like piezoelectric elements 6a, 7a, 8a, 9a arranged at the four corners on the sides of the plate 3 and the outer ends of the piezoelectric unimorphs 6 to 9 from the front side of the plate 3 The apparatus includes a hollow substrate 11 disposed so as to cover the substrate, and a hollow holding plate 13 made of a conductive metal plate sandwiching the piezoelectric unimorphs 6 to 9 and the plate 3 with the substrate 11.
[0018]
The plate 3 is formed by punching a thin plate-shaped (about 0.05 mm thick) conductive material made of a conductive metal (eg, beryllium copper, stainless steel for a spring) using etching, electric discharge machining, or the like. ).
That is, the plate 3 has an outer frame 31 having substantially the same size (outer size: about 20 mm × 20 mm) as the holding plate 13, and a substantially square mirror which is positioned substantially at the center of the outer frame 31 and has the reflection mirror 5 provided on the surface. A portion 33 and a folded shape that extends vertically from a diagonal portion of the mirror portion 33 and changes in a rectangular waveform around a central axis (rotation axis) Z passing through the center of the mirror portion 33 in the left-right width direction. A pair of spring portions 35 and 37 (hatched portions in FIGS. 1 and 2) as torsional vibrating portions and outer ends of the spring portions 35 and 37 are coupled to each other, and the spring portions 35 and 37 and the mirror portion 33 are connected to each other. A surrounding inner frame 39, and mounting portions 46, 47, 48, and 49 for forming piezoelectric unimorphs 6 to 9 extending from upper and lower left and right ends of the hollow portion of the outer frame 31 toward the rotation axis Z of the mirror portion 33; , Of these four mounting portions 46 to 49, T-shaped connecting portions 41 and 43 for connecting the mounting portions 46, 47 and 48 and 49 facing each other and the upper and lower ends of the inner frame 39 on the rotation axis Z of the mirror portion 33, respectively. Have been.
[0019]
Here, the spring portions 35 and 37 support the mirror portion 33 from both sides, and rotate the mirror portion 33 about the rotation axis Z by its own torsional vibration. For this reason, at the time of vibration, stress tends to concentrate at the inner corner portion (corner) of the turn as shown by C in FIG. Therefore, each corner is slightly rounded (so-called R). In this embodiment, in order to further reduce the concentrated stress, the width A of the portion orthogonal to the rotation axis Z is The width B of the parallel portion is increased. This is because the apexes of the rectangular waves parallel to the rotation axis Z are greatly twisted in the spring portions 35 and 37 formed in a rectangular wave shape. The strength of 35 and 37 is increased.
[0020]
The spring portions 35 and 37 are connected to diagonal positions on the facing surface of the mirror portion 33 and the inner frame 39. This is to enable the mirror portion 33 and the inner frame 39 to be connected without providing an unnecessary turn in each of the spring portions 35 and 37, whereby the plate 3 becomes large in the vertical direction. Has been prevented.
[0021]
In this embodiment, a silicon mirror having a high reflection coating made of aluminum is used for the reflection mirror 5 provided in the mirror section 33, and the reflection mirror 5 is made of an adhesive or the like in the mirror section 33. Glued.
Next, the four piezoelectric unimorphs 6 to 9 are formed by bonding plate-shaped piezoelectric elements 6 a to 9 a to the mounting portions 46 to 49, of which the mounting portions 46 and 47 above the plate 3. Are used as driving piezoelectric unimorphs as a vibrating means for applying a driving force for torsional vibration to the connecting portion 41 to torsional vibrate the spring portion 35. The piezoelectric unimorphs 8 and 9 formed on the mounting parts 48 and 49 are used as a sensor piezoelectric unimorph that detects the torsional vibration of the spring part 37 via the connection part 43.
[0022]
That is, in this embodiment, since the plate 3 is formed of a spring material made of a conductive metal, if the plate-like piezoelectric elements 6a to 9a are bonded to the mounting portions 46 to 49, the plate 3 It becomes a common electrode of the piezoelectric elements 6a to 9a. Then, as shown in FIG. 3A, electrodes 26 to 29 are provided on the side opposite to the mounting portions 46 to 49 of the piezoelectric elements 6 a to 9 a, and a voltage is applied between the electrodes 26 to 29 and the plate 3. Is applied, the piezoelectric unimorphs 6 to 9 are displaced in a predetermined direction as shown in FIG. 3B. Conversely, when a voltage generated between the electrodes 26 to 29 and the plate 3 is detected, the piezoelectric unimorphs 6 to 9 are displaced. The displacement amounts of 6 to 9 can be detected.
[0023]
Therefore, in the present embodiment, a conductive material (for example, silver paste) for forming an electrode is applied to both surfaces of each of the piezoelectric elements 6a to 9a, and the driving piezoelectric unimorphs 6, 7 and the sensor piezoelectric unimorphs 8, 9 are respectively constituted. Each of the piezoelectric elements 6a, 7a and 8a, 9a is orthogonal to the mounting portions 46 to 49 and opposite to each other as shown by arrows in FIG. The elements 6a to 9a are adhered to the mounting portions 46 to 49, and further, as shown in FIG. 1A, electrodes 26 to 29 for applying a voltage are formed on the substrate 11 at positions corresponding to the piezoelectric elements 6a to 9a. The outer ends of the piezoelectric unimorphs 6 to 9 are held between the substrate 11 and the holding plate 13 by applying an electrode pattern and tightening the substrate 11 and the holding plate 13 with screws 13a to 13d.
[0024]
Therefore, in the optical scanner device 1 of the present embodiment, as shown in FIG. 1A, the ground lead 25a is connected to the ground terminal 25 passed through the screw 13d by soldering or the like, and Lead wires 26a, 27a for applying a drive voltage are connected to the formed electrodes 26, 27 by soldering or the like, and a holding plate serving as a common electrode with the electrodes 26, 27 is connected via the lead wires 26a, 27a. When a high driving voltage is applied between the piezoelectric unimorphs 6 and 7 (and thus the plate 3), the driving piezoelectric unimorphs 6 and 7 are inverted with respect to each other about the fixed portion as shown by arrows in FIG. The torque can be generated around the rotation axis Z of the connecting portion 41 by displacing in the direction. Therefore, if the driving voltage is set to AC, a vibration torque is generated around the rotation axis Z of the connection portion 41, and the spring portion 35 and thus the reflection mirror 5 are vibrated about the rotation axis Z. it can.
[0025]
Further, as shown in FIG. 1A, lead wires 28a, 29a for voltage detection are connected to electrodes 28, 29 formed on the substrate 11 by soldering or the like, and are connected via the lead wires 28a, 29a. By detecting the voltage generated between each of the electrodes 28 and 29 and the holding plate 13 serving as a common electrode, it is possible to detect the torsional vibration transmitted from the reflection mirror 5 via the spring portion 37 and the connection portion 43.
[0026]
Since the substrate 11 holds the entire optical scanner device 1, a hard insulator substrate such as a glass epoxy resin is used for this purpose. Also, as is clear from FIGS. 1 and 2, in the plate 3, the connecting portions 41 and 43 are thinner than the widths of the mounting portions 46 to 49, but this deforms the connecting portions 41 and 43 (in other words, This is to make it easier to expand and contract. That is, by doing so, the driving force from the driving piezoelectric unimorphs 6 and 7 can be efficiently transmitted to the spring portion 35, and the vibration of the spring portion 37 can be efficiently transmitted to the sensor piezoelectric unimorphs 8 and 9. It is.
[0027]
Next, FIG. 4 illustrates a configuration of a drive circuit 50 that actually operates the optical scanner device 1 of the present embodiment. This drive circuit is a so-called self-excited oscillation circuit that causes the optical scanner device 1 to vibrate at its resonance frequency.
As shown in FIG. 4, detection signals (voltages) from the sensor piezoelectric unimorphs 8, 9 taken out through the lead wires 28a, 29a are combined by a common signal line 51 and guided to the drive circuit 50. Then, in the drive circuit 50, the combined detection signal is branched into two systems.
[0028]
One of the branched detection signals is converted into a DC voltage according to the amplitude of the oscillation waveform of the optical scanner device 1 by passing through the amplifier 53, the rectifier circuit 55, and the smoothing circuit 57. Then, this DC voltage is input to the differential amplifier 59, where the DC voltage is converted into a DC voltage corresponding to a difference from the reference voltage output from the reference voltage generation source 61. The other of the branched detection signals passes through an amplifier 63, a phase shifter 65, a low-pass filter 67, and an amplifier 69, thereby removing higher harmonic components. It is converted into a vibration signal for generating a drive signal that is in phase with the actual vibration.
[0029]
Then, the vibration signal and the output signal (DC voltage) from the differential amplifier 59 are input to the multiplier 71 and converted into a signal corresponding to the product of these signals. Further, this signal is further input to a transformer 75 via an amplifier 73, and is boosted to a voltage (about 35 V AC) at which the piezoelectric unimorphs 6 and 7 can be driven in the transformer 75. The boosted voltage signal (alternating current) is guided to the lead wires 26a and 27a of the driving piezoelectric unimorphs 6 and 7 via the signal line 77, and is applied to each of the piezoelectric unimorphs 6 and 7 as a driving signal. Is done.
[0030]
As a result, the optical scanner device 1 self-oscillates at its own resonance frequency, and its scanning angle is defined as a constant scanning angle by the reference voltage. Then, by connecting a terminal 79 to the signal line 51 and extracting detection signals from the piezoelectric unimorphs 8 and 9 for the sensor from the terminal 79, the vibration state of the optical scanner device 1 and, consequently, scanning of the reflection mirror 5 can be achieved. The position can be monitored. For example, when the optical scanner device 1 is used as a barcode reader, it can be used for detecting a decoding timing at the time of reading a barcode.
[0031]
The drive circuit 50 is a self-excited oscillation circuit as described above because the optical scanner device 1 is of a resonance type and its resonance frequency changes due to a change in ambient temperature or the like. That is, if the optical scanner device 1 is driven by a drive signal having a preset resonance frequency, the frequency of the drive signal deviates from the resonance frequency of the optical scanner device 1 due to a change in the surrounding environment. In the present embodiment, the drive circuit 50 is a self-excited oscillation circuit, so that the drive signal follows a change in the resonance frequency of the optical scanner device 1 and the optical scanner device 1 It is possible to vibrate at a frequency.
[0032]
As described above, in the optical scanner device 1 of the present embodiment, the spring parts 35 and 37 as torsional vibrating parts are provided on both sides of the mirror part 33 forming the reflection mirror 5 in the plate 3 constituting the light deflecting element. At the same time, the spring portions 35 and 37 are formed in a rectangular wave shape, and the piezoelectric unimorphs 6 and 7 are formed on the mounting portions 47 and 46 that form a part of a connecting portion that connects the spring portion 35 and the outer frame 31. By doing so, the vibrating means is configured.
[0033]
Therefore, according to the present embodiment, unlike the conventional device, it is not necessary to support the vibration generating means (coil) by the spring portions 35 and 37, and the spring portions 35 and 37 can be made smaller. In particular, in this embodiment, since the spring portions 35 and 37 are formed in a rectangular wave shape, the overall length of the spring portions 35 and 37 is reduced while the substantial length of the spring portions 35 and 37 is secured. it can. Therefore, according to the present embodiment, it is possible to reduce the size of the plate 3 and, consequently, the optical scanner device 1 while securing the scanning angle.
[0034]
Since the width B of the portion parallel to the rotation axis Z is larger than the width A of the portion orthogonal to the rotation axis Z, the strength of the spring portions 35 and 37 can be increased. Further, since the spring portions 35 and 37 are connected at diagonal positions on the opposing surfaces of the mirror portion 33 and the inner frame 39, the spring portions 35 and 37 are not provided with unnecessary folding. , The mirror part 33 and the inner frame 39 can be connected. Therefore, according to the present embodiment, even with such a configuration, the spring portions 35 and 37 can be made smaller while ensuring the strength and vibration characteristics of the spring portions 35 and 37, and the plate 3, and consequently, the optical scanner device 1 can be made smaller. Can be downsized.
[0035]
Further, since the spring portions 35 and 37 are formed in a rectangular wave shape, they are easily deformed when subjected to an external force. However, in this embodiment, the entire plate 3 is surrounded by the outer frame 31, and the spring portions 35 and 37 and Since the mirror portion 33 is surrounded by the inner frame 39, it is possible to prevent the plate 3 itself from buckling or the spring portions 35 and 37 from being deformed by an external force when the optical scanner device 1 is assembled. Therefore, handling of the plate 3 at the time of assembly or the like can be easily performed, and workability can be improved.
[0036]
Further, in this embodiment, since the piezoelectric unimorphs 6 and 7 formed on the mounting portions 47 and 46 of the plate 3 are used as the vibrating means, a separate member for generating vibration is provided as in a conventional device using a coil. There is no need to simplify the configuration of the device and reduce the size. In particular, in this embodiment, not only the driving piezoelectric unimorphs 6 and 7 constituting the vibrating means but also the sensor piezoelectric unimorphs 8 as the detecting means for detecting the vibration state of the optical scanner device 1 are provided on the plate 3. Since the self-excited oscillation circuit is used for the drive circuit as described above, not only can the optical scanner device 1 be self-excitedly vibrated, but also the vibration state of the optical scanner device 1 can be monitored. It is also possible to detect the scanning position, operation abnormality, and the like.
[0037]
As mentioned above, although one Example of this invention was described, this invention is not limited to the said Example, It can take various aspects.
For example, in the above-described embodiment, the spring portions 35 and 37 are formed in a folded shape of a rectangular wave. However, as shown in FIG. Similarly to (2), since there are two turns, the shape is S-shaped). In this case, the stress applied to each corner at the folded portions of the spring portions 35 and 37 can be further reduced, and the strength of the spring portions 35 and 37 can be further increased.
[0038]
In the above embodiment, the inner frame 39 is provided to reinforce the spring portions 35 and 37. If there is no particular problem in handling, the inner frame 39 is removed as shown in FIG. Alternatively, the spring portions 35 and 37 may be directly connected to the connection portions 41 and 43. In this case, in order to rotate the mirror portion 33 around the center axis as the rotation axis Z, the connection position of the spring portions 35 and 37 to the mirror portion 33 and the connection portions 41 and 43 is determined by the center axis of the mirror portion 33 ( That is, it is necessary to set the position on the rotation axis).
[0039]
On the other hand, in the above embodiment, electrodes 26 to 29 for applying a drive voltage or detecting voltages to the respective piezoelectric unimorphs 6 to 9 are formed on the substrate 11, and lead wires 26 a to 29 a are connected to the electrodes. Each of the piezoelectric unimorphs 6 to 9 is connected to the drive circuit 50 by using the lead wires 26a to 29a, but as shown in FIG. 6A, the back surface of the substrate 11 on which the electrodes 26 to 29 are formed. In addition, wiring patterns 25a 'to 29a' corresponding to the lead wires 25a to 29a and an electrode pattern 25 'corresponding to the ground terminal 25 are formed, and the wiring patterns 25a' to 29a 'are formed below the substrate 11. The electrode patterns 25b to 29b serving as connection terminals are concentrated on the surface of the substrate 11 to be in contact with the electrode pattern 25 'serving as the ground terminal 25, as shown in FIG. By forming an electrode pattern 25 "that is, the connection between the piezoelectric unimorph 6-9 and the drive circuit 50 may be performed through the electrode patterns 25b~29b which is concentrated below the substrate 11.
[0040]
That is, when the board 11 is configured as a printed board in which each of the lead wires 25a to 29a is formed by printed wiring as described above, as shown in FIGS. The plate 3 is interposed therebetween, and the conductive screws 11a and 11b are passed through the conductive screws 11a and 11b from the substrate 11 at a plurality of locations (two locations in the figure) including portions where the electrode patterns 25 'and 25 "serving as the ground terminals 25 are formed. When the substrate 11 and the holding plate 13 are tightened and fixed, the electrode patterns 26b to 29b concentrated below the substrate 11 can be connected to the surface sides of the piezoelectric unimorphs 6 to 9, and the ground electrode pattern 25b And the holding plate 13 serving as a common terminal of each of the piezoelectric unimorphs 6 to 9 can be connected via the screw 11a, the electrode patterns 25 ″ and 25 ′, and the wiring pattern 25a ′.
[0041]
In this case, for example, as shown in FIG. 7B, a connector 80 having terminals 85 to 89 connected to the respective electrode patterns 25b to 29b is provided on the lower surface side of the substrate 11, and FIG. As shown, if the connector 80 is connected to the connector 90 fixed to the printed circuit board 91 on which the drive circuit 50 is formed, the connection between the optical scanner device 1 and the drive circuit 50 is made using a lead wire. This can be easily performed without any need, and the man-hours during manufacturing can be reduced, and the reliability of wiring can be improved.
[0042]
Note that, in this case, the connector 80 is not provided on the board 11, and the printed circuit board 91 on which the drive circuit 50 is formed or the connector provided at an arbitrary mounting position of the optical scanner device 1 is connected to the electrode patterns 25 b to 29 b of the board 11. The drive circuit 50 and each of the electrode patterns 25b to 29b may be directly inserted and connected via the connector.
[0043]
Next, in the above embodiment, the plate 3 constituting the light deflecting element is formed of a spring material made of a conductive metal. However, as the spring material, a semiconductor material such as silicon can be used. With this configuration, a drive circuit can be formed on the plate, and the entire optical scanner device including the drive circuit can be further reduced in size. Further, in this case, the mass production of the plate 3 can be achieved by using the etching, and the manufacturing cost can be reduced. However, in this case, the mounting portions 46 to 49 forming the piezoelectric unimorphs 6 to 9 need to be coated with a conductive metal (for example, silver paste or the like).
[0044]
Furthermore, in the above-described embodiment, the description has been given assuming that the reflection mirror 5 made of silicon is provided on the mirror portion 33 of the plate 3. However, as this reflection mirror 5, a mirror-finished glass or resin is used. May be. Alternatively, the mirror portion 33 itself may be mirror-finished, and a high-reflection coating may be directly formed on the mirror portion 33 by aluminum evaporation or the like to form a reflection mirror.
[0045]
In the above embodiment, the piezoelectric unimorphs 6 to 9 formed by bonding the piezoelectric elements 6a to 9a to one surface of the mounting portions 46 to 49 of the plate 3 are used as the vibration means and the detection means for detecting the vibration. Although described as those, a piezoelectric bimorph that can be formed by, for example, bonding a piezoelectric element to both surfaces of the mounting portions 46 to 49 may be used as these units. In this case, the polarization direction of each piezoelectric element may be the same as in the above embodiment.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing the configuration of an entire optical scanner device according to an embodiment, where (a) is a rear view and (b) is a front view.
FIGS. 2A and 2B are explanatory diagrams illustrating the shape of a plate of the optical scanner device according to the embodiment, wherein FIG. 2A is an overall view thereof and FIG. 2B is an enlarged view of a spring portion.
FIG. 3 is an explanatory diagram illustrating a configuration (a) and an operation (b) of a piezoelectric unimorph according to an embodiment.
FIG. 4 is a block diagram illustrating a configuration of a drive circuit according to an embodiment.
FIG. 5 is an explanatory diagram illustrating another configuration example of a plate constituting the light deflecting element.
FIGS. 6A and 6B show a configuration example of a substrate on which printed wiring is provided, wherein FIG. 6A is a rear view and FIG. 6B is a front view.
FIGS. 7A and 7B are schematic diagrams showing the overall configuration of an optical scanner device using the substrate of FIG. 6, wherein FIG. 7A is a rear view and FIG. 7B is a front view.
FIG. 8 is an explanatory diagram when the optical scanner device shown in FIG. 7 and a drive circuit are connected via a connector.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Optical scanner device 3 ... Plate (light deflection element) 5 ... Reflection mirror
6, 7: Piezoelectric unimorph (for driving) 8, 9: Piezoelectric unimorph (for sensor) 6a to 9a: Piezoelectric element 11: Substrate 13: Holding plate 25: Ground terminal 26 to 29: Electrode 31: Outer frame 33: Mirror section 35, 37 ... spring part
39: inner frame 41, 43: connecting part 46-49: mounting part
50: drive circuit 80: connector

Claims

A mirror portion on which a reflection surface for reflecting light is formed; a pair of torsional vibrating portions supporting the mirror portion from both sides; an outer frame surrounding the mirror portion and the torsional vibrating portion; and the mirror of each of the torsional vibrating portions The portion is provided with a light deflecting element formed by a single plate member, and a connecting portion for connecting the end portion on the opposite side and the outer frame, and the torsion vibration of the torsional vibration portion causes the mirror portion to An optical scanner device that scans light by rotating around a rotation axis connecting the connection points of the torsional vibrating portions and the connection portions,
Each of the torsional vibrating portions has a folded shape that changes in a rectangular wave shape around the rotation axis, and one of the connecting portions that connects the torsional vibrating portion and the outer frame vibrates the torsional vibrating portion. set the vibration means,
Further, each of the torsional vibrating portions is formed in a sinusoidal folded shape in which a corner of the rectangular wave is rounded .

A mirror portion on which a reflection surface for reflecting light is formed; a pair of torsional vibrating portions supporting the mirror portion from both sides; an outer frame surrounding the mirror portion and the torsional vibrating portion; and the mirror of each of the torsional vibrating portions The portion is provided with a light deflecting element formed by a single plate member, and a connecting portion for connecting the end portion on the opposite side and the outer frame, and the torsion vibration of the torsional vibration portion causes the mirror portion to An optical scanner device that scans light by rotating around a rotation axis connecting the connection points of the torsional vibrating portions and the connection portions,
Each of the torsional vibrating portions has a folded shape that changes in a rectangular wave shape around the rotation axis, and has a shape in which a width of a portion parallel to the rotation axis is larger than a width of a portion orthogonal to the rotation axis. An optical scanner device, further comprising: a vibrating means for vibrating the torsional vibrating portion at one connecting portion connecting the torsional vibrating portion and the outer frame.

The light deflection element is further coupled to said coupling portion and the connecting portion and each of the torsional vibration unit, according to claim 1, characterized in that it comprises an inner frame surrounding the each torsional vibration portion and the mirror portion or The optical scanner device according to claim 2 .

A mirror portion on which a reflection surface for reflecting light is formed; a pair of torsional vibrating portions supporting the mirror portion from both sides; an outer frame surrounding the mirror portion and the torsional vibrating portion; and the mirror of each of the torsional vibrating portions The portion is provided with a light deflecting element formed by a single plate member, and a connecting portion for connecting the end portion on the opposite side and the outer frame, and the torsion vibration of the torsional vibration portion causes the mirror portion to An optical scanner device that scans light by rotating around a rotation axis connecting the connection points of the torsional vibrating portions and the connection portions,
The light deflecting element further includes an inner frame coupled to a coupling portion between each of the torsional vibrating portions and the coupling portion, and surrounding the torsional vibrating portions and the mirror portion.
Each of the torsional vibrating portions has a folded shape that changes in a rectangular wave shape around the rotation axis ,
Both ends of each of the torsional vibrating portions are respectively coupled to diagonal positions of opposing portions of the mirror portion and the inner frame,
Wherein the one connecting portion for connecting the said outer frame and torsional vibration unit, light scanner device, wherein the vibration means to vibrate the torsional vibration portion is provided.

The connecting portion is protruded from the inside of the outer frame toward the rotating shaft, and a pair of mounting portions for mounting the vibrating means, and both ends of the mounting portion are connected and substantially at the center position. A connection portion to which the torsional vibration portion is coupled,
At least the surfaces of the pair of mounting portions have conductivity,
The vibrating means is made of a plate-like piezoelectric element which is bonded to one or both surfaces of the pair of mounting portions and forms a piezoelectric unimorph or a piezoelectric bimorph that displaces each mounting portion in a different direction by applying a voltage. The optical scanner device according to claim 1, wherein:

A mirror portion on which a reflection surface for reflecting light is formed; a pair of torsional vibrating portions supporting the mirror portion from both sides; an outer frame surrounding the mirror portion and the torsional vibrating portion; and the mirror of each of the torsional vibrating portions The portion is provided with a light deflecting element formed by a single plate member, and a connecting portion for connecting the end portion on the opposite side and the outer frame, and the torsion vibration of the torsional vibration portion causes the mirror portion to An optical scanner device that scans light by rotating around a rotation axis connecting the connection points of the torsional vibrating portions and the connection portions,
Each of the torsional vibrating portions has a folded shape that changes in a rectangular wave shape around the rotation axis ,
Wherein the one connecting portion for connecting the said outer frame and torsional vibration unit, the vibration means is provided to vibrate the torsional vibration unit,
The connecting portion is protruded from the inside of the outer frame toward the rotating shaft, and a pair of mounting portions for mounting the vibrating means, and both ends of the mounting portion are connected and substantially at the center position. A connection portion to which the torsional vibration portion is coupled,
At least the surfaces of the pair of mounting portions have conductivity,
The vibrating means is composed of a plate-like piezoelectric element that is bonded to one or both surfaces of the pair of mounting portions, and constitutes a piezoelectric unimorph or a piezoelectric bimorph that displaces each mounting portion in a different direction by applying a voltage,
An optical scanner device, wherein an outer frame side end of the piezoelectric unimorph or the piezoelectric bimorph is sandwiched between a substrate on which wiring for voltage application is patterned and a conductive metal plate .