JP3694924B2 - Objective lens driving apparatus and recording / reproducing apparatus using the same - Google Patents

Description

【００２２】
かかる対物レンズ駆動装置１００は、小型化を図るために、弾性部材１２０の弾性変位部分の長さ寸法Ｌを短くしたり、厚み寸法ｔを小さくされている。上記数式（１）より明らかなように、弾性部材１２０の基本特性を決定する一次共振周波数（ｆ_０）は、弾性部材１２０の弾性変位部分の長さ寸法Ｌに関して、フォーカシング方向及びトラッキング方向のいずれにおいてもｆ_０＝αＬ^３／２ の関係にある。但し、αは、比例定数とする。
【００２３】
【発明が解決しようとする課題】
上述した対物レンズ駆動装置１００は、対物レンズ２を駆動させた際、フォーカシング方向及びトラッキング方向とに二次共振が発生することが避けられない。このため、対物レンズ駆動装置１００は、弾性部材１２０の基端部１２１に共振現象を抑制する粘弾性材を添着することによって、二次共振の抑制を図っている。
【００２４】
対物レンズ駆動装置１００は、図１２に示すように、板状の弾性部材１２０が、主面が水平に互いに平行にそれぞれ配設されているため、フォーカシング方向とトラッキング方向とで形状が異なっていた。したがって、対物レンズ駆動装置１００は、図１３に示すように、弾性部材１２０の基端部１２１のトラッキング方向の変位量がフォーカシング方向の変位量に比較して小さいため、振動抑制効果（以下、ダンピング効果と称する。）が充分に発揮されていないという問題点があった。すなわち、対物レンズ駆動装置１００は、対物レンズ２を駆動させた際、特にトラッキング方向において、板状の弾性部材１２０が低周波数帯域の二次共振を充分に抑制することができないという問題点があった。
【００２５】
そこで、本発明は、対物レンズをフォーカシング方向とトラッキング方向とに弾性変位自在に支持する弾性部材のトラッキング方向の変位量を大きくすることによって二次共振を抑制することを可能とし、以って感度特性の向上を達成した対物レンズ駆動装置及びこれを用いた記録再生装置を提供することを目的とする。
【００２６】
【課題を解決するための手段】
この目的を達成した本発明に係る対物レンズ駆動装置及びこれを用いた記録再生装置は、対物レンズと、一端側には対物レンズが組み付けられるホルダ部が形成されるとともに、他端側には対物レンズの光軸と平行な方向に作用する磁気駆動力を発生するフォーカシングコイルと、対物レンズの光軸と直交する方向に作用する磁気駆動力を発生するトラッキングコイルとが組み付けられたボビン部材と、このボビン部材の両側面部にそれぞれ光軸と平行な方向に離間して配置され、一端部が固定されるとともに他端部が固定部であるボビン支持部材に固定されることによってボビン部材をフォーカシング方向とトラッキング方向とに弾性変位自在に支持する複数個の弾性部材と、マグネットが接合されるとともにフォーカシングコイルの内部に介挿される第１のヨークと、トラッキングコイルと対向するようにして位置された第２のヨークとが立ち上がり形成されることによって磁気回路部を構成しかつボビン支持部材を固定支持するベース部材とを備え、上記複数個の弾性部材は、それぞれ板バネ材によって形成され、上記ボビン支持部材に取り付けられる基端部と、上記ボビン部材に取り付けられる嵌合部と、上記基端部と直交する方向に形成された連結片を介して互いに連結された第１の折返し片と第２の折返し片とによって形成される折返し部と、上記嵌合部と上記第２の折返し片との間に上記第２の折返し片に連続して形成される弾性変形部とを有するとともに、上記ベース部材と平行な平面に対してそれぞれ傾斜されて配置され、上記折返し部には、上記弾性部材の共振現象を抑制する粘弾性材が添着されている。
【００２７】
また、本発明に係る対物レンズ駆動装置及びこれを用いた記録再生装置において、複数個の弾性部材は、ベース部材と平行な平面及びこの平面と直交する平面とに対して面対称にそれぞれ傾斜されて配置されるように構成してもよい。さらに、本発明に係る対物レンズ駆動装置及びこれを用いた記録再生装置において、上記第１の折返し片及び上記第２の折返し片は、それぞれ上記基端部に平行する方向に形成され、上記第１の折返し片と上記基端部とは、上記基端部と直交する方向に形成された第２の連結片を介して連結されて第２の折返し部を形成するように構成してもよい。
【００２８】
【作用】
以上のように構成された本発明に係る対物レンズ駆動装置及びこれを用いた記録再生装置によれば、複数個の弾性部材が、ベース部材と平行な平面に対してそれぞれ傾斜された状態でボビンを支持している。このため、対物レンズ駆動装置は、ボビンを支持する弾性部材をそれぞれ傾斜させて設けることによって、低周波数帯域における二次共振時に生じるトラッキング方向の変位量が大きくなる。したがって、この対物レンズ駆動装置は、トラッキング方向の変位量が大きくなることによって、ダンピング効果が充分に発揮されて二次共振を抑制する。
【００２９】
また、本発明によれば、弾性部材がベース部材と平行な平面及びこの平面と直交する平面とに対して面対称にそれぞれ傾斜されて配設されることによって、フォーカシング方向及びトラッキング方向との両方向に同時にダンピング効果が発揮されて二次共振を抑制する。
【００３０】
さらに、本発明によれば、折返し部が形成されるとともにこの折返し部に共振を抑制する粘弾性材が添着されることによって、フォーカシング方向及びトラッキング方向とに発生する二次共振を更に抑制する。
【００３１】
【実施例】
以下、本発明の具体的な実施例を図面を参照して詳細に説明する。本発明に係る対物レンズ駆動装置１は、後述する弾性部材２０の配設状態に特徴を有し、基本的な構成を上述した従来の対物レンズ駆動装置１００とほぼ同様とした板バネ形構造の直交２軸アクチュエータ機構を備えた対物レンズ駆動装置である。したがって、以下の説明においては、上述した従来の対物レンズ駆動装置１００と同一部材には同一番号を付す。なお、対物レンズ駆動装置１は、後述するように４本の弾性部材２０Ａ乃至弾性部材２０Ｄを備えているが、これらを共通して説明する場合には単に弾性部材２０と表現する。
【００３２】
すなわち、対物レンズ駆動装置１は、図１乃至図３に示すように、対物レンズ２と、この対物レンズ２が組み付けられた対物レンズホルダ３と、この対物レンズホルダ３及び磁気回路部４を構成する後述する各部材が組み合わされたボビン部材５と、このボビン部材５を支持するところの後述する４本の弾性部材２０（２０Ａ乃至２０Ｄ）と、これら弾性部材２０の基端部を支持するボビン支持部材６及び磁性材料によって形成されたベース部材７とを主たる構成部材として構成されている。
【００３３】
ボビン部材５は、合成樹脂材料によって成形され、上述した対物レンズホルダ３が組み付けられるホルダ部８と、磁気回路部４の構成各部材が組み合わされる磁気回路部品組付け部９とから構成されている。ホルダ部８は、対物レンズ２を組み合わせた対物レンズホルダ３が嵌合される対物レンズ取付け穴１０が設けられた全体が薄厚の筒状部として構成されている。また、このホルダ部８には、対物レンズ取付け穴１０に嵌合された対物レンズ３の外周面を保持する複数の保持片１７Ａ乃至保持片１７Ｃが一体に形成されている。
【００３４】
ボビン部材５の磁気回路部品組付け部９は、略々凸字状の大きな開口部として構成され、対物レンズ２を光軸と平行な方向に駆動変位させる磁気駆動力を発生させるフォーカシングコイル１２と、対物レンズ２を光軸と直交する方向に駆動変位させる磁気駆動力を発生させる一対のトラッキングコイル１３Ａ、１３Ｂが組み付けられる。フォーカシングコイル１２は、対物レンズ取付け穴１０と反対側のやや幅広の開口部側に位置して磁気回路部品組付け部９に組み付けられる。
【００３５】
磁気回路部品組付け部９に対応するボビン部材５の両側面部には、後述する弾性部材２０Ａ乃至弾性部材２０Ｄのそれぞれの嵌合部２３Ａ乃至嵌合部２３Ｄが差し込まれる水平方向の嵌合スリット５ａ乃至嵌合スリット５ｄがそれぞれ上下方向に離間して設けられている。したがって、ボビン部材５は、これら弾性部材２０Ａ乃至弾性部材２０Ｄによって、上下方向及び左右方向に弾性変位自在に支持されることになる。
【００３６】
フォーカシングコイル１２は、磁気回路部品組付け部９を構成するコイル組付け開口部１１の開口寸法とほぼ同径の角筒状を呈しており、このコイル組付け開口部１１に嵌着されて組み付けられる。また、フォーカシングコイル１２は、コイル組付け開口部１１に組み付けられた後、外周面と開口部内壁との間に接着剤が充填されることによって、ボビン部材５にしっかりと固定される。また、フォーカシングコイル１２は、コイル組付け開口部１１に組み付けられた状態において、コイルの巻き方向が対物レンズ２の光軸と直交する方向であるように構成されている。
【００３７】
トラッキングコイル１３Ａ、１３Ｂは、それぞれ薄幅の矩形枠状を呈して構成されており、フォーカシングコイル１２の一方側面部と対物レンズとの間に位置するようにして、互いに一方側面部を重ね合わせるようにして磁気回路部品組付け部９を構成するコイル組付け開口部１１に嵌着されて組み付けられる。これらトラッキングコイル１３Ａ、１３Ｂは、フォーカシングコイル１２の一方側面部に接着剤によってしっかりと固定される。また、これらトラッキングコイル１３Ａ、１３Ｂは、磁気回路部品組付け部９に組み付けられた状態において、少なくとも相対向する辺に対物レンズ２の光軸と平行な直線部分を有するように構成されている。
【００３８】
ベース部材７は、詳細な形状の図示を省略するが、珪素鋼等の高透磁率材料によって略々Ｈ字状に形成され、中央連結片の相対向する側縁部から第１のヨーク片１４Ａと第２のヨーク片１４Ｂとがそれぞれ互いに平行に対峙するようにして一体に立ち上がり形成されている。
【００３９】
第１のヨーク片１４Ａは、磁気回路部品組付け部９に組み付けられたフォーカシングコイル１２の中心孔を貫通している。また、第２のヨーク片１４Ｂは、トラッキングコイル１３Ａ、１３Ｂと対向して磁気回路部品組付け部９に貫通している。第１のヨーク片１４Ａには、第２のヨーク片１４Ｂとの対向側面に、やや厚みのある板状のマグネット１５が接着剤等を用いてしっかりと取付け固定されている。第１のヨーク片１４Ａと第２のヨーク片１４Ｂとの先端部には、図１において鎖線で示すように、磁性材で形成したヨーク板１６が組み合わされる。
【００４０】
したがって、磁気回路部４は、上述したベース部材７と、このベース部材７に一体に立ち上がり形成された第１のヨーク片１４Ａ及び第２のヨーク片１４Ｂと、第１のヨーク片１４Ａに取り付けられたマグネット１５及びヨーク板１６とから構成される。そして、フォーカシングコイル１２及びトラッキングコイル１３Ａ、１３Ｂは、この磁気回路部４の磁界中を横切るように位置して磁気回路部品組付け部９に組み付けられている。また、これらフォーカシングコイル１２及びトラッキングコイル１３Ａ、１３Ｂへの電流の供給は、後述するように、弾性部材２０Ａ乃至弾性部材２０Ｄを利用して行われている。
【００４１】
ボビン支持部材６は、第１のヨーク片１４Ａ及び第２のヨーク片１４Ｂの反対側に位置して、中央開口部分を跨ぐようにしてベース部材７に組み付けられている。すなわち、ボビン支持部材６は、底面部に図示しない半導体レーザから出射された光束の光路を構成する逆Ｕ字状の凹部６ａが形成されるとともに、両側面部にはボビン部材５を支持する弾性部材２０Ａ乃至弾性部材２０Ｄの基端部２１Ａ乃至基端部２１Ｄがそれぞれ差し込まれる嵌合スリット６ｂ乃至嵌合スリット６ｅがそれぞれ上下方向に離間して傾斜されて設けられている。
【００４２】
弾性部材２０Ａ乃至弾性部材２０Ｄは、例えば、リン青銅やベリリウム銅等の薄いバネ板材料を打ち抜き形成した部材であって、ボビン支持部材６の左側面部に組み付けられる弾性部材２０Ａ、２０Ｂと、右側面部に組み付けられる弾性部材２０Ｃ、２０Ｄとは互いに上下及び左右に対象形とされるとともに、同一側面部に組み付けられる弾性部材２０Ａ、２０Ｂ及び弾性部材２０Ｃ、２０Ｄとは互いに同一形状とされている。
【００４３】
図４を参照してこれら弾性部材２０の構成を説明すれば、弾性部材２０は、ボビン支持部材６の両側面部に設けた嵌合スリット６ｂ乃至嵌合スリット６ｄにそれぞれ差し込まれる略矩形状の基端部２１と、幅狭の弾性変形部２２と、ボビン部材５の両側面部に設けた嵌合スリット５ａ乃至嵌合スリット５ｄにそれぞれ差し込まれる略矩形状の嵌合部２３とから構成されている。弾性部材２０の基端部２１の近傍には、互いに組み合わされた状態でＬ字状の開口部３０と矩形状の開口部３１とを打ち抜くことによって、全体が略Ｕ字状を呈する折返し部２９が形成されている。
【００４４】
すなわち、折返し部２９は、基端部２１と直交する方向の連結片２７を介して互いに連結された基端部２１と平行する方向の第１の折返し片２６及び第２の折返し片２８とから構成されている。外側に位置する第２の折返し片２８は、そのまま弾性変形部２２と連続している。なお、基端部２１の他端部３３は、折返し部２９を囲むように切り残されてリード線接続部として構成されている。
【００４５】
また、弾性部材２０は、嵌合部２３の一端側に、弾性変形部２２と平行なコイル接続片２４が一体に形成されている。このコイル接続片２４には、ボビン部材５の上下面に形成された半球状の位置決めダボ３２に対応して位置決め孔２５が設けられている。
【００４６】
弾性部材２０Ａ乃至弾性部材２０Ｄは、基端部２１Ａ乃至基端部２１Ｄがボビン支持部材６の両側面部に設けた嵌合スリット６ｂ乃至嵌合スリット６ｄにそれぞれ差し込まれて固定されることにより、ボビン支持部材６にそれぞれ片持ち状態で支持される。そして、弾性部材２０Ａ乃至弾性部材２０Ｄは、自由端側の嵌合部２３Ａ乃至嵌合部２３Ｄがボビン部材５の両側面部に設けた嵌合スリット５ａ乃至嵌合スリット５ｄにそれぞれ差し込まれて固定されることにより、このボビン部材５を上下方向及び左右方向に弾性支持する。
【００４７】
また、弾性部材２０Ａ乃至弾性部材２０Ｄは、ボビン部材５をボビン支持部材６に弾性支持するように、これら両部材間に組み合わせられた状態において、コイル接続片２４の位置決め孔２５がボビン部材５の位置決めダボ３２にそれぞれ相対係合される。コイル接続片２４には、フォーカシングコイル１２及びトラッキングコイル１３Ａ、１３Ｂのコイル線がそれぞれ接続される。また、基端部２１のリード線接続部３３には、フォーカシングコイル１２及びトラッキングコイル１３Ａ、１３Ｂに駆動電流を供給する駆動源とを接続するリード線が接続される。したがって、弾性部材２０は、フォーカシングコイル１２及びトラッキングコイル１３Ａ、１３Ｂへの電流供給線としても機能する。
【００４８】
なお、本発明は、上述した弾性部材２０に限定されるものではなく、種々展開されるものである。すなわち、基端部の近傍に形成される折返し部は、弾性変形部の長手方向であるＸ軸と、トラッキング方向であるＹ軸によって構成される面、換言すればベース部材と平行な面内において、Ｘ軸方向に対して少なくとも１箇所に略Ｕ字状に連続して折り返された部位として構成されればよく、折返し片の長さ寸法、幅寸法或いは折返し部の数等については、ダンピングの付与方法等、対物レンズ駆動装置の設計条件に応じて設定される。また、ベース部材と直交する方向を幅寸法とした弾性部材については、トラッキング方向であるＹ軸とフォーカシング方向であるＺ軸によって構成される面内で、上述した折返し部が形成されることは勿論である。
【００４９】
さらに、弾性部材２０Ａ乃至２０Ｄは、折返し部２９に、共振を抑制する粘弾性材５０Ａ乃至５０Ｄがそれぞれ添着されている。ここで、弾性部材２０Ａ乃至２０Ｄに添着される粘弾性材５０Ａ乃至５０Ｄとしては、一般にブチル、ゴム等の減衰特性の大きい粘弾性を有するゲル状の合成樹脂材料等が用いられるが、例えば、紫外線硬化型の合成樹脂を用いた場合には、紫外線の照射量を制御することによって所望の粘弾性率を得ることができ、極めて効果的である。
【００５０】
そして、弾性部材２０Ａ乃至２０Ｄは、図５及び図６に示すように、ボビン支持部材６に、ベース部材７と平行な平面及びこの平面と直交する平面に対して面対称にそれぞれ傾斜されて配設されている。そして、これら弾性部材２０Ａ乃至２０Ｄは、ベース部材７に平行な平面に対して、ほぼ４５度の傾斜角でそれぞれ傾斜されている。これらの弾性部材２０Ａ、２０Ｂ及び弾性部材２０Ｃ、２０Ｄは、図９に示すように、ボビン支持部材６の内方に開かれた断面ハ字状を呈してそれぞれ配設されている。
【００５１】
以上のように構成された対物レンズ駆動装置１を備えた光ピックアップ装置は、半導体レーザから出射された光束を対物レンズ２を介して光ディスクの情報記録面に照射するとともに、この情報記録面からの反射光を対物レンズ２を介してビームスプリッタによって分光し、フォーカシング方向とトラッキング方向との差異をディテクターによって検出する。検出されたフォーカシング方向とトラッキング方向の位置ずれは、フォーカスエラー信号或いはトラッキングエラー信号としてサーボ回路で処理され、それらに応じた駆動電流がフォーカシングコイル１２及びトラッキングコイル１３Ａ、１３Ｂへ供給される。
【００５２】
対物レンズ駆動装置１は、フォーカシングコイル１２にフォーカスエラー信号に応じた駆動電流が供給されると、このフォーカシングコイル１２に流れる電流と、磁気回路部４を構成するマグネット１５からの磁束とによって、ボビン部材５をフォーカシング方向へと駆動する磁気駆動力を発生させる。この磁気駆動力は、弾性部材２０Ａ乃至弾性部材２０Ｄを上下方向に弾性変位させ、ボビン部材５、換言すれば対物レンズ２を光軸と平行なフォーカシング方向へと調動させて、光ディスクに照射する半導体レーザのフォーカシングの調整を行わせる。
【００５３】
対物レンズ駆動装置１は、第１のトラッキングコイル１３Ａ又は第２のトラッキングコイル１３Ｂに、トラッキングエラー信号に応じた駆動電流が供給されると、これらトラッキングコイル１３Ａ、１３Ｂに流れる電流と、磁気回路部４を構成するマグネット１５からの磁束とによって、ボビン部材５をトラッキング方向へと駆動する磁気駆動力を発生させる。この磁気駆動力は、弾性部材２０Ａ乃至弾性部材２０Ｄを左右方向へと弾性変位させ、ボビン部材５、換言すれば対物レンズ２を光軸と直交するトラッキング方向へと調動させて、光ディスクに照射する半導体レーザのトラッキングの調整を行わせる。
【００５４】
つぎに、弾性部材２０Ａ乃至２０Ｄについて、対物レンズ２が駆動された際における変位動作を図７を参照して説明する。弾性部材２０Ａ乃至２０Ｄは、図７に示すように、対物レンズ２が駆動された際、弾性変形部２２Ａ乃至２２Ｄのほぼ中央部を支点としてトラッキング方向にそれぞれ変位されることによって、折返し部２９Ａ乃至２９Ｄのトラッキング方向の変位量が大きくされている。したがって、弾性部材２０は、ダンピング効果が充分に発揮されて、二次共振を抑制する。
【００５５】
上述したように、対物レンズ駆動装置１によれば、弾性部材２０Ａ乃至２０Ｄが、ベース部材７と平行な平面に対してそれぞれ傾斜されて配設されたことによって、対物レンズ２が駆動された際のトラッキング方向の変位量が大きくされるため、ダンピング効果を充分に発揮させることができる。したがって、この対物レンズ駆動装置１は、トラッキング方向の低周波数帯域における二次共振を抑制されて感度特性を向上させることが可能とされる。
【００５６】
また、対物レンズ駆動装置１は、弾性部材２０Ａ乃至２０Ｄが、ベース部材７と平行な平面及びこの平面と直交する平面とに対して面対称にそれぞれ４５度の傾斜角で傾斜されて配設された弾性部材２０Ａ乃至２０Ｄを備えることによって、フォーカシング方向及びトラッキング方向との両方向に同時に粘弾性材によるダンピング効果を発揮することができる。したがって、この対物レンズ駆動装置１は、二次共振が抑制されて良好な振動特性が得られるとともに、感度特性を向上することが可能とされる。
【００５７】
さらに、対物レンズ駆動装置１によれば、折返し部２９が形成されるとともにこの折返し部２９に共振を抑制する粘弾性材５０Ａ乃至５０Ｄが添着された弾性部材２０Ａ乃至２０Ｄを備えることによって、フォーカシング方向及びトラッキング方向との二次共振が更に抑制されて良好な振動特性が得られるとともに、感度特性を向上させることが可能とされる。
【００５８】
本発明は、上述した弾性部材の配設状態に限定されるものでなく適宜変更しても良い。
【００５９】
例えば、弾性部材２０Ａ乃至２０Ｄは、図８及び図９に示すように、ボビン支持部材６に、ベース部材７と平行な平面及びこの平面と直交する平面に対して面対称にそれぞれ傾斜されて配設されている。これら弾性部材２０Ａ乃至２０Ｄは、ベース部材７に平行な平面に対して、ほぼ４５度の傾斜角でそれぞれ傾斜されている。これら弾性部材２０Ａ、２０Ｂ及び弾性部材２０Ｃ、２０Ｄは、図９に示すように、ボビン支持部材６の外方に開かれた断面ハ字状を呈してそれぞれ配設されている。
【００６０】
上述したように配設された弾性部材２０Ａ乃至２０Ｄは、図１０に示すように、対物レンズ２が駆動された際、折返し部２９Ａ乃至２９Ｄをほぼ支点としてトラッキング方向にそれぞれ変位され、トラッキング方向の変位量が大きくされている。したがって、弾性部材２０は、ダンピング効果が充分に発揮されて、二次共振を抑制する。
【００６１】
尚、基本的な構成は、上述した対物レンズ駆動装置１とほぼ同一であるので、共通する部材には共通の符号を付して詳細な説明は省略する。図８及び図９に示すように構成された対物レンズ駆動装置は、弾性部材２０Ａ乃至２０Ｄが、ベース部材７と平行な平面に対してそれぞれ傾斜されて配設されたことによって、対物レンズ２が駆動された際のトラッキング方向の変位量が大きくされ、ダンピング効果を充分に発揮させることができる。したがって、この対物レンズ駆動装置は、トラッキング方向の低周波数帯域における二次共振を抑制されて感度特性を向上させることが可能とされる。
【００６２】
また、この弾性部材２０Ａ乃至２０Ｄを用いた対物レンズ駆動装置は、弾性部材２０Ａ乃至２０Ｄが、ベース部材７と平行な平面及びこの平面と直交する平面とに対して面対称にそれぞれ４５度の傾斜角で傾斜されて配設されることによって、フォーカシング方向及びトラッキング方向との両方向に同時にダンピング効果を発揮することができる。したがって、この対物レンズ駆動装置は、二次共振が抑制されて良好な振動特性が得られるとともに、感度特性を向上させることが可能とされる。
【００６３】
【発明の効果】
本発明に係る対物レンズ駆動装置及びこれを用いた記録再生装置によれば、ベース部材と平行な平面に対してそれぞれ傾斜されて配設された複数個の弾性部材を備えることによって、対物レンズが駆動された際のトラッキング方向の変位量が大きくされるため、ダンピング効果を充分に発揮させることができる。したがって、この対物レンズ駆動装置は、トラッキング方向の低周波数帯域における二次共振を抑制されて感度特性を向上させることが可能とされる。
【００６４】
また、本発明に係る対物レンズ駆動装置によれば、ベース部材と平行な平面及びこの平面と直交する平面とに対して面対称にそれぞれ傾斜されて配設された複数個の弾性部材を備えることによって、フォーカシング方向及びトラッキング方向との両方向に同時にダンピング効果を発揮することができる。したがって、この対物レンズ駆動装置は、二次共振が抑制されて良好な振動特性が得られるとともに、感度特性を向上させることが可能とされる。
【００６５】
さらに、本発明に係る対物レンズ駆動装置によれば、少なくとも１箇所に折り返された部位が連続して構成される折返し部が形成されるとともにこの折返し部に共振を抑制する粘弾性材が添着された複数個の弾性部材を備えることによって、フォーカシング方向及びトラッキング方向との二次共振が更に抑制されて良好な振動特性が得られるとともに、感度特性を向上させることが可能とされる。
【図面の簡単な説明】
【図１】本発明に係る対物レンズ駆動装置を示す全体斜視図である。
【図２】上記対物レンズ駆動装置を示す全体平面図である。
【図３】上記対物レンズ駆動装置を示す全体側面図である。
【図４】上記対物レンズ駆動装置に用いられる弾性部材を一部省略して示した斜視図である。
【図５】上記弾性部材の配設状態を示す斜視図である。
【図６】上記弾性部材の配設状態を示す正面図である。
【図７】上記弾性部材の変位状態を示す平面図である。
【図８】本発明に係る対物レンズ駆動装置を構成する弾性部材の他の例を示す平面図である。
【図９】他の例の弾性部材の配設状態を示す正面図である。
【図１０】他の例の弾性部材の変位状態を示す平面図である。
【図１１】従来の対物レンズ駆動装置を示す斜視図である。
【図１２】従来の対物レンズ駆動装置を構成する弾性部材の配設状態を示す斜視図である。
【図１３】従来の対物レンズ駆動装置を構成する弾性部材を説明するために示す平面図である。
【符号の説明】
１ 対物レンズ駆動装置、 ２ 対物レンズ、 ５ ボビン部材、 ６ ボビン支持部材、 ７ ベース部材、 ８ ホルダ部、 ９ 磁気回路部品組付け部、１１ コイル組付け開口部、 １２ フォーカシングコイル、 １３ トラッキングコイル、 １４ ヨーク、 １５ マグネット、 ２０（２０Ａ乃至２０Ｄ） 弾性部材、 ２１ 基端部、 ２２ 弾性変形部、 ２３ 嵌合部、 ２９ 折返し部、 ５０ 粘弾性材[0001]
[Industrial application fields]
The present invention relates to an objective lens driving device and a recording / reproducing device using the same.
[0002]
[Prior art]
2. Description of the Related Art An optical disk recording / reproducing apparatus that uses a disk-shaped optical recording medium (hereinafter, collectively referred to as an optical disk) such as an optical disk or a magneto-optical disk as a recording medium reproduces an information signal recorded on the optical disk or records an information signal. An optical pickup device is provided. This optical pickup device includes a semiconductor laser as a light source that emits a light beam applied to an information signal recording surface of an optical disc, an optical system block including optical components such as a beam splitter that separates return light from the optical disc, and a semiconductor laser. And an objective lens driving device for converging the light beam emitted from the information signal recording surface of the optical disc by the objective lens and causing the light beam to follow the recording track.
[0003]
The objective lens driving device includes a direction in which the objective lens is perpendicular to the information signal recording surface of the optical disc, that is, a focusing direction parallel to the optical axis of the objective lens, and an inner and outer peripheral direction of the information signal recording surface of the optical disc, that is, the optical axis of the objective lens. Is a device that adjusts in a tracking direction orthogonal to. In this objective lens driving device, for example, the objective lens is adjusted in a range of 2 mm in the focusing direction and 0.8 mm in the tracking direction, so that the orthogonal 2 using the magnetic driving force generated by the control current supplied to the coil arranged in the magnetic field is used. A shaft actuator mechanism is provided.
[0004]
In addition, the orthogonal two-axis actuator mechanism that has been put into practical use includes a spring support structure that provides smooth drive characteristics without friction, and shaft rotation that is easy to obtain assembly accuracy and excellent in maintaining the tilt posture of the objective lens. A sliding structure method is provided. In addition, the orthogonal biaxial actuator mechanism of the spring support structure type is divided into a moving coil type and a moving magnet type, and the orthogonal biaxial actuator mechanism of the axial rotation sliding structure type is divided into an inner optical path type and an outer optical path type. It is done.
[0005]
On the other hand, in an orthogonal biaxial actuator mechanism of a spring support structure type, a hinge-type structure, a wire-type structure, or a leaf spring-type structure is known as the structure of the elastic member that holds the objective lens. An orthogonal two-axis actuator mechanism having a leaf spring type structure is extremely effective for downsizing the objective lens driving device from the viewpoint of workability or operation characteristics.
[0006]
As shown in FIG. 11, a conventional objective lens driving device 100 having an orthogonal biaxial actuator mechanism having such a leaf spring structure includes an objective lens 2, an objective lens holder 3 to which the objective lens 2 is assembled, A bobbin member 5 in which members described later constituting the objective lens holder 3 and the magnetic circuit unit 4 are combined, four elastic members 120 (120A to 120D) for supporting the bobbin member 5, and the elastic members 120. A bobbin support member 6 that supports the base end portion and a base member 7 formed of a magnetic material are configured as main components.
[0007]
The bobbin member 5 includes a holder portion 8 to which the above-described objective lens holder 3 is assembled and a magnetic circuit component assembly portion 9 to which the constituent members of the magnetic circuit portion 4 are combined. The holder portion 8 is provided with an objective lens mounting hole 10 into which the objective lens holder 3 is fitted. The holder portion 8 is integrally formed with a plurality of holding pieces 17A to 17C that hold the outer surface of the objective lens holder 3 fitted in the objective lens mounting hole 10.
[0008]
The magnetic circuit component assembly portion 9 of the bobbin member 5 includes a focusing coil 12 that generates a magnetic driving force that drives and displaces the objective lens 2 in a direction parallel to the optical axis, and the objective lens 2 in a direction orthogonal to the optical axis. A pair of tracking coils 13A and 13B and a pair of yoke pieces 14A and 14B that generate a magnetic driving force for driving displacement are assembled. The focusing coil 12 is configured such that the winding direction of the coil is parallel to the optical axis of the objective lens 2 in a state where the focusing coil 12 is assembled to the magnetic circuit component assembly unit 9. The tracking coils 13 </ b> A and 13 </ b> B are configured to have linear portions parallel to the optical axis of the objective lens 2 at least on opposite sides when assembled in the magnetic circuit component assembly 9.
[0009]
The base member 7 is integrally formed so that the first yoke piece 14A and the second yoke piece 14B face each other in parallel. The first yoke piece 14 </ b> A passes through the center hole of the focusing coil 12 assembled in the magnetic circuit component assembly part 9. Further, the second yoke piece 14B passes through the magnetic circuit component assembling portion 9 so as to face the tracking coils 13A and 13B. A plate-like magnet 15 having a slight thickness is attached to the first yoke piece 14A on the side surface facing the second yoke piece 14B. As shown by a chain line in FIG. 11, a yoke plate 16 is combined with the tip portions of the first yoke piece 14A and the second yoke piece 14B.
[0010]
Therefore, the magnetic circuit unit 4 includes the above-described base member 7, the first and second yoke pieces 14A and 14B that are integrally formed on the base member 7, and the magnet attached to the first yoke piece 14A. 15 and a yoke plate 16. The focusing coil 12 and the tracking coils 13A and 13B are respectively arranged so as to cross the magnetic field of the magnetic circuit unit 4. The current is supplied to the focusing coil 12 and the tracking coils 13A and 13B using the elastic members 120A to 120D, respectively.
[0011]
The bobbin support member 6 is assembled and fixed on the base member 7 on the opposite side of the first yoke piece 14A and the second yoke piece 14B. That is, the bobbin support member 6 is formed with an inverted U-shaped recess 6a constituting an optical path of a light beam emitted from a semiconductor laser (not shown) on the bottom surface, and elastic members 120A to 120D on both side surfaces. The horizontal fitting slits 6b to 6e into which the base end portions are respectively inserted are provided apart from each other in the vertical direction.
[0012]
The elastic members 120A to 120D are members formed by punching a thin spring plate material, and have the same shape on the left and right sides. As shown in FIG. 12, the elastic member 120 has a narrow elastic deformation portion 122 integrally projecting from one side edge of the rectangular base end portion 121, and the bobbin member 5 is formed at the distal end portion of the elastic deformation portion 122. The fitting part 123 is formed. The fitting portion 123 is integrally formed with a coil connection portion 124 provided with a positioning hole that engages with an alignment dowel formed in the bobbin member 5.
[0013]
Although not shown, viscoelastic materials are attached to the elastic members 120, respectively. As the viscoelastic material, for example, an ultraviolet curable resin material is used, and the resonance operation generated when the elastic member 120 is elastically displaced is suppressed, or the vibration is quickly attenuated.
[0014]
In the objective lens driving apparatus 100 configured as described above, when a driving current corresponding to a focus error signal is supplied to the focusing coil 12, the current flowing in the focusing coil 12 and the magnets that constitute the magnetic circuit unit 4 are provided. The magnetic drive force for driving the bobbin member 5 in the focusing direction is generated by the magnetic flux from 15. This magnetic driving force adjusts the focusing of the semiconductor laser that irradiates the optical disk by adjusting the objective lens 2 in a focusing direction parallel to the optical axis.
[0015]
The elastic member 120 having the base end portion 121 supported by the bobbin support member 6 causes the bobbin member 5, that is, the objective lens 2 to be moved by the elastic deformation portion 122 being elastically displaced in the vertical direction in FIG. It moves up and down.
[0016]
When the driving current corresponding to the tracking error signal is supplied to the first tracking coil 13A or the second tracking coil 13B, the objective lens driving device 100 emits light from the objective lens 2 of the tracking coil 13A or the tracking coil 13B. A magnetic driving force for driving the bobbin member 5 in the tracking direction is generated by the current flowing through the portion parallel to the axis and the magnetic flux from the magnet 15 constituting the magnetic circuit unit 4. This magnetic driving force causes the objective lens 2 to adjust in the tracking direction orthogonal to the optical axis, thereby adjusting the tracking of the semiconductor laser irradiated onto the optical disk.
[0017]
The elastic member 120 having the base end portion 121 supported by the bobbin support member 6 causes the bobbin member 5, that is, the objective lens 2 to be moved when the elastic deformation portion 122 is elastically displaced in the horizontal direction in FIG. It moves left and right.
[0018]
In the objective lens driving device 100 described above, the objective lens 2, the objective lens holder 3, the bobbin member 5, the focusing coil 12, and the tracking coil 13 constitute a movable part as a whole, and serve as the elastic members 120A to 120D. Supported and tuned in the focusing or tracking direction. The elastic members 120A to 120D can be regarded as both-end fixed beams because the elastic members 120A to 120D are members having one end fixed to the bobbin member 5 and the other end fixed to the bobbin support member 6.
[0019]
Further, in the objective lens driving device, the displacement operation of the movable part constituted by each member described above is substantially constant in the low frequency band with respect to the input current, but the frequency is high in the high band exceeding a certain frequency value. As it rises, a vibration operation with a small amplitude occurs at an inclination of −40 db / dec. This specific frequency value, that is, the primary resonance frequency (f ₀ ) determines the basic characteristics of the elastic member 120 and varies depending on the shape and material.
[0020]
Therefore, in the objective lens driving device 100, the movable part constituted by each member described above is regarded as the concentrated mass M, the length dimension of the elastic displacement portion of the elastic member 120 is L, the width dimension is b, and the thickness dimension. Is t and Young's modulus is E, the primary resonance frequency (f ₀ ) in the focusing direction can be expressed by the following equation (1). The primary resonance frequency (f ₀ ) in the tracking direction is expressed by exchanging the width dimension b and the thickness dimension t.
[0021]
[Expression 1]

[0022]
In the objective lens driving apparatus 100, the length dimension L of the elastic displacement portion of the elastic member 120 is shortened or the thickness dimension t is reduced in order to reduce the size. As is clear from the above formula (1), the primary resonance frequency (f ₀ ) that determines the basic characteristics of the elastic member 120 is either the focusing direction or the tracking direction with respect to the length L of the elastic displacement portion of the elastic member 120. In FIG. ₅ , f ₀ = αL ^3/2 . However, α is a proportionality constant.
[0023]
[Problems to be solved by the invention]
In the objective lens driving apparatus 100 described above, when the objective lens 2 is driven, it is inevitable that secondary resonance occurs in the focusing direction and the tracking direction. For this reason, the objective lens driving device 100 attempts to suppress secondary resonance by attaching a viscoelastic material that suppresses the resonance phenomenon to the base end portion 121 of the elastic member 120.
[0024]
As shown in FIG. 12, the objective lens driving device 100 has different shapes in the focusing direction and the tracking direction because the plate-like elastic members 120 are arranged with the main surfaces horizontally and parallel to each other. . Therefore, as shown in FIG. 13, the objective lens driving apparatus 100 has a vibration suppression effect (hereinafter referred to as damping) because the displacement amount of the base end portion 121 of the elastic member 120 is smaller than the displacement amount in the focusing direction. There is a problem that the effect is not fully exhibited. That is, the objective lens driving device 100 has a problem that when the objective lens 2 is driven, the plate-like elastic member 120 cannot sufficiently suppress the secondary resonance in the low frequency band, particularly in the tracking direction. It was.
[0025]
Therefore, the present invention makes it possible to suppress the secondary resonance by increasing the amount of displacement in the tracking direction of the elastic member that supports the objective lens in an elastically displaceable manner in the focusing direction and the tracking direction. An object of the present invention is to provide an objective lens driving device that achieves improved characteristics and a recording / reproducing device using the same.
[0026]
[Means for Solving the Problems]
The objective lens driving device and the recording / reproducing apparatus using the same according to the present invention that achieves this object include an objective lens and a holder portion to which the objective lens is assembled on one end side, and an objective lens on the other end side. A bobbin member in which a focusing coil that generates a magnetic driving force acting in a direction parallel to the optical axis of the lens and a tracking coil that generates a magnetic driving force acting in a direction perpendicular to the optical axis of the objective lens are assembled; The bobbin member is arranged on both side surfaces of the bobbin member so as to be separated from each other in a direction parallel to the optical axis. One end portion is fixed and the other end portion is fixed to a bobbin support member which is a fixing portion. internal focusing coil and a plurality of elastic member elastically supported displaceably in the tracking direction, together with the magnet is bonded A base member that constitutes a magnetic circuit unit and that fixes and supports a bobbin support member by forming a first yoke to be inserted and a second yoke positioned so as to face the tracking coil. The plurality of elastic members are each formed of a leaf spring material, and are attached to the bobbin support member, a base end portion attached to the bobbin member, and a direction orthogonal to the base end portion. A folded portion formed by a first folded piece and a second folded piece connected to each other via the formed coupling piece; and the second folded piece between the fitting portion and the second folded piece. and having an elastically deformable portion which is formed continuously to the folded piece of, it is arranged to be inclined respectively relative to the base member and a plane parallel to the said folded portion, co of the elastic member To suppress the phenomenon viscoelastic material is affixed.
[0027]
In the objective lens driving device and the recording / reproducing device using the same according to the present invention, the plurality of elastic members are inclined in plane symmetry with respect to a plane parallel to the base member and a plane orthogonal to the plane. You may comprise so that it may arrange | position. Furthermore, in the objective lens driving device and the recording / reproducing device using the same according to the present invention, the first folded piece and the second folded piece are each formed in a direction parallel to the base end portion, and The one folded piece and the base end portion may be connected via a second connecting piece formed in a direction orthogonal to the base end portion to form a second folded portion. .
[0028]
[Action]
According to the objective lens driving device and the recording / reproducing device using the same according to the present invention configured as described above, the bobbin is in a state where the plurality of elastic members are inclined with respect to the plane parallel to the base member. Support. For this reason, in the objective lens driving device, the amount of displacement in the tracking direction generated at the time of the secondary resonance in the low frequency band becomes large by providing the elastic members supporting the bobbins so as to be inclined. Therefore, this objective lens driving device exhibits a damping effect sufficiently and suppresses secondary resonance by increasing the amount of displacement in the tracking direction.
[0029]
Further, according to the present invention, the elastic member is disposed so as to be symmetrical with respect to a plane parallel to the base member and a plane perpendicular to the plane, so that both directions of the focusing direction and the tracking direction are provided. At the same time, the damping effect is exerted to suppress the secondary resonance.
[0030]
Furthermore, according to the present invention, a secondary resonance that occurs in the focusing direction and the tracking direction is further suppressed by forming a folded portion and attaching a viscoelastic material that suppresses resonance to the folded portion.
[0031]
【Example】
Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. The objective lens driving device 1 according to the present invention is characterized by the arrangement state of an elastic member 20 to be described later, and has a leaf spring structure in which the basic configuration is substantially the same as the conventional objective lens driving device 100 described above. It is an objective lens drive device provided with an orthogonal biaxial actuator mechanism. Therefore, in the following description, the same members as those in the conventional objective lens driving device 100 described above are denoted by the same reference numerals. The objective lens driving device 1 includes four elastic members 20A to 20D as will be described later. However, when these are described in common, they are simply expressed as the elastic member 20.
[0032]
That is, the objective lens driving device 1 includes an objective lens 2, an objective lens holder 3 to which the objective lens 2 is assembled, an objective lens holder 3 and a magnetic circuit unit 4 as shown in FIGS. A bobbin member 5 in which each member to be described later is combined, four elastic members 20 (20A to 20D) which support the bobbin member 5, and a bobbin which supports the base end portion of the elastic member 20 The support member 6 and the base member 7 formed of a magnetic material are configured as main components.
[0033]
The bobbin member 5 is formed of a synthetic resin material, and includes a holder portion 8 to which the above-described objective lens holder 3 is assembled, and a magnetic circuit component assembly portion 9 in which the constituent members of the magnetic circuit portion 4 are combined. . The holder portion 8 is configured as a thin cylindrical portion as a whole provided with an objective lens mounting hole 10 into which the objective lens holder 3 combined with the objective lens 2 is fitted. The holder portion 8 is integrally formed with a plurality of holding pieces 17A to 17C that hold the outer peripheral surface of the objective lens 3 fitted in the objective lens mounting hole 10.
[0034]
The magnetic circuit component assembly portion 9 of the bobbin member 5 is configured as a large opening having a substantially convex shape, and a focusing coil 12 that generates a magnetic driving force that drives and displaces the objective lens 2 in a direction parallel to the optical axis. A pair of tracking coils 13A and 13B for generating a magnetic driving force for driving and displacing the objective lens 2 in a direction orthogonal to the optical axis are assembled. The focusing coil 12 is mounted on the magnetic circuit component mounting portion 9 at a slightly wider opening side opposite to the objective lens mounting hole 10.
[0035]
Horizontal fitting slits 5a into which respective fitting portions 23A to 23D of elastic members 20A to 20D described later are inserted in both side surface portions of the bobbin member 5 corresponding to the magnetic circuit component assembly portion 9. Thru | or the fitting slit 5d are spaced apart and provided in the up-down direction, respectively. Accordingly, the bobbin member 5 is supported by the elastic members 20A to 20D so as to be elastically displaceable in the vertical direction and the horizontal direction.
[0036]
The focusing coil 12 has a rectangular tube shape having substantially the same diameter as the opening dimension of the coil assembly opening portion 11 constituting the magnetic circuit component assembly portion 9, and is fitted into the coil assembly opening portion 11 for assembly. It is done. In addition, the focusing coil 12 is firmly fixed to the bobbin member 5 by being assembled into the coil assembly opening 11 and then filled with an adhesive between the outer peripheral surface and the inner wall of the opening. Further, the focusing coil 12 is configured such that the coil winding direction is a direction orthogonal to the optical axis of the objective lens 2 in a state where the focusing coil 12 is assembled in the coil assembly opening 11.
[0037]
Each of the tracking coils 13A and 13B is configured to have a thin rectangular frame shape, and is positioned between one side surface of the focusing coil 12 and the objective lens so that the one side surface is overlapped with each other. Thus, the magnetic circuit component assembly part 9 is fitted into the coil assembly opening 11 and assembled. These tracking coils 13A and 13B are firmly fixed to one side surface of the focusing coil 12 by an adhesive. The tracking coils 13A and 13B are configured to have linear portions parallel to the optical axis of the objective lens 2 at least on opposite sides when assembled in the magnetic circuit component assembly portion 9.
[0038]
Although the detailed illustration of the base member 7 is omitted, the base member 7 is formed in a substantially H shape by a high magnetic permeability material such as silicon steel, and the first yoke piece 14A is formed from the opposite side edges of the central connecting piece. And the second yoke piece 14B are integrally formed so as to face each other in parallel.
[0039]
The first yoke piece 14 </ b> A passes through the center hole of the focusing coil 12 assembled in the magnetic circuit component assembly part 9. Further, the second yoke piece 14B passes through the magnetic circuit component assembling portion 9 so as to face the tracking coils 13A and 13B. A slightly thick plate-like magnet 15 is firmly attached and fixed to the first yoke piece 14A on the side surface facing the second yoke piece 14B using an adhesive or the like. As shown by a chain line in FIG. 1, a yoke plate 16 formed of a magnetic material is combined with the tip portions of the first yoke piece 14A and the second yoke piece 14B.
[0040]
Therefore, the magnetic circuit unit 4 is attached to the base member 7 described above, the first yoke piece 14A and the second yoke piece 14B that are formed integrally with the base member 7, and the first yoke piece 14A. And a magnet plate 15 and a yoke plate 16. The focusing coil 12 and the tracking coils 13 </ b> A and 13 </ b> B are assembled to the magnetic circuit component assembly unit 9 so as to cross the magnetic field of the magnetic circuit unit 4. In addition, the current is supplied to the focusing coil 12 and the tracking coils 13A and 13B by using the elastic members 20A to 20D as will be described later.
[0041]
The bobbin support member 6 is located on the opposite side of the first yoke piece 14A and the second yoke piece 14B, and is assembled to the base member 7 so as to straddle the central opening portion. That is, the bobbin support member 6 is formed with an inverted U-shaped recess 6a that forms an optical path of a light beam emitted from a semiconductor laser (not shown) on the bottom surface portion, and an elastic member that supports the bobbin member 5 on both side surface portions. The fitting slit 6b to fitting slit 6e into which the base end portion 21A to base end portion 21D of 20A to elastic member 20D are respectively inserted are inclined and provided apart from each other in the vertical direction.
[0042]
The elastic members 20A to 20D are members formed by punching a thin spring plate material such as phosphor bronze or beryllium copper, for example, elastic members 20A and 20B assembled to the left side surface portion of the bobbin support member 6, and the right side surface portion. The elastic members 20C and 20D assembled in the upper and lower sides are subject to the vertical and horizontal shapes, and the elastic members 20A and 20B and the elastic members 20C and 20D assembled in the same side surface have the same shape.
[0043]
If the structure of these elastic members 20 is demonstrated with reference to FIG. 4, the elastic member 20 is a substantially rectangular base inserted in the fitting slit 6b thru | or the fitting slit 6d provided in the both sides | surfaces of the bobbin support member 6, respectively. It is comprised from the edge part 21, the narrow elastic deformation part 22, and the substantially rectangular fitting part 23 each inserted in the fitting slit 5a thru | or the fitting slit 5d provided in the both-sides surface part of the bobbin member 5. . In the vicinity of the base end portion 21 of the elastic member 20, an L-shaped opening portion 30 and a rectangular opening portion 31 are punched out in a state of being combined with each other, whereby a folded portion 29 having a substantially U-shape as a whole. Is formed.
[0044]
That is, the folded portion 29 is formed from the first folded piece 26 and the second folded piece 28 in the direction parallel to the base end portion 21 connected to each other via the connecting piece 27 in the direction orthogonal to the base end portion 21. It is configured. The second folded piece 28 located on the outside continues to the elastic deformation portion 22 as it is. The other end portion 33 of the base end portion 21 is cut off so as to surround the folded portion 29 and is configured as a lead wire connecting portion.
[0045]
Further, the elastic member 20 is integrally formed with a coil connection piece 24 parallel to the elastic deformation portion 22 on one end side of the fitting portion 23. The coil connection piece 24 is provided with positioning holes 25 corresponding to the hemispherical positioning dowels 32 formed on the upper and lower surfaces of the bobbin member 5.
[0046]
The elastic member 20A to the elastic member 20D are fixed by inserting the base end portion 21A to the base end portion 21D into the fitting slit 6b to the fitting slit 6d provided on both side surfaces of the bobbin support member 6, respectively. Each of the support members 6 is supported in a cantilever state. The elastic members 20A to 20D are fixed by inserting the fitting portions 23A to 23D on the free end side into the fitting slits 5a to 5d provided on both side surfaces of the bobbin member 5, respectively. Thus, the bobbin member 5 is elastically supported in the vertical direction and the horizontal direction.
[0047]
Further, the elastic member 20A to the elastic member 20D have the positioning hole 25 of the coil connection piece 24 of the bobbin member 5 in a state where the bobbin member 5 is elastically supported by the bobbin support member 6 and is combined between these two members. The positioning dowels 32 are relatively engaged with each other. The coil connecting piece 24 is connected with the coil wires of the focusing coil 12 and the tracking coils 13A and 13B. The lead wire connecting portion 33 of the base end portion 21 is connected to a lead wire that connects the focusing coil 12 and a driving source that supplies a driving current to the tracking coils 13A and 13B. Therefore, the elastic member 20 also functions as a current supply line to the focusing coil 12 and the tracking coils 13A and 13B.
[0048]
In addition, this invention is not limited to the elastic member 20 mentioned above, A various expansion | deployment is carried out. That is, the folded portion formed in the vicinity of the base end portion is in a plane constituted by the X axis that is the longitudinal direction of the elastic deformation portion and the Y axis that is the tracking direction, in other words, in a plane parallel to the base member. In this case, it may be configured as a part that is continuously folded in a substantially U shape at least at one place with respect to the X-axis direction. The length dimension, width dimension, number of folded parts, etc. It is set according to the design conditions of the objective lens driving device, such as the application method. In the elastic member having a width dimension in the direction perpendicular to the base member, the above-described folded portion is formed in the plane constituted by the Y axis that is the tracking direction and the Z axis that is the focusing direction. It is.
[0049]
Further, in the elastic members 20A to 20D, viscoelastic materials 50A to 50D for suppressing resonance are attached to the folded portion 29, respectively. Here, as the viscoelastic materials 50A to 50D attached to the elastic members 20A to 20D, a gel-like synthetic resin material having a large viscoelasticity such as butyl or rubber is generally used. When a curable synthetic resin is used, a desired viscoelastic modulus can be obtained by controlling the irradiation amount of ultraviolet rays, which is extremely effective.
[0050]
As shown in FIGS. 5 and 6, the elastic members 20 </ b> A to 20 </ b> D are arranged on the bobbin support member 6 so as to be inclined with respect to a plane parallel to the base member 7 and a plane perpendicular to the plane. It is installed. The elastic members 20 </ b> A to 20 </ b> D are each inclined at an inclination angle of approximately 45 degrees with respect to a plane parallel to the base member 7. These elastic members 20A, 20B and elastic members 20C, 20D are respectively arranged to have a cross-sectional C shape opened inward of the bobbin support member 6, as shown in FIG.
[0051]
The optical pickup device including the objective lens driving device 1 configured as described above irradiates the information recording surface of the optical disc with the light beam emitted from the semiconductor laser via the objective lens 2, and from the information recording surface. The reflected light is dispersed by the beam splitter through the objective lens 2 and the difference between the focusing direction and the tracking direction is detected by the detector. The detected misalignment between the focusing direction and the tracking direction is processed by the servo circuit as a focus error signal or a tracking error signal, and a drive current corresponding to them is supplied to the focusing coil 12 and the tracking coils 13A and 13B.
[0052]
When the driving current corresponding to the focus error signal is supplied to the focusing coil 12, the objective lens driving device 1 uses the current flowing through the focusing coil 12 and the magnetic flux from the magnet 15 constituting the magnetic circuit unit 4 to generate a bobbin. A magnetic driving force for driving the member 5 in the focusing direction is generated. This magnetic driving force is a semiconductor that irradiates an optical disc by elastically displacing the elastic members 20A to 20D in the vertical direction and adjusting the bobbin member 5, in other words, the objective lens 2 in a focusing direction parallel to the optical axis. Adjust the laser focusing.
[0053]
When the objective lens driving device 1 is supplied with a driving current corresponding to the tracking error signal to the first tracking coil 13A or the second tracking coil 13B, the current flowing through the tracking coils 13A and 13B and the magnetic circuit unit The magnetic driving force for driving the bobbin member 5 in the tracking direction is generated by the magnetic flux from the magnet 15 constituting the motor 4. This magnetic driving force irradiates the optical disk by elastically displacing the elastic members 20A to 20D in the left-right direction and adjusting the bobbin member 5, in other words, the objective lens 2 in the tracking direction orthogonal to the optical axis. The tracking of the semiconductor laser is adjusted.
[0054]
Next, displacement operations of the elastic members 20A to 20D when the objective lens 2 is driven will be described with reference to FIG. As shown in FIG. 7, when the objective lens 2 is driven, the elastic members 20A to 20D are displaced in the tracking direction with the substantially central portions of the elastic deformation portions 22A to 22D as fulcrums. The displacement amount in the tracking direction of 29D is increased. Therefore, the elastic member 20 exhibits a damping effect sufficiently and suppresses secondary resonance.
[0055]
As described above, according to the objective lens driving device 1, the elastic members 20 </ b> A to 20 </ b> D are disposed so as to be inclined with respect to the plane parallel to the base member 7, so that the objective lens 2 is driven. Since the amount of displacement in the tracking direction is increased, the damping effect can be sufficiently exerted. Therefore, the objective lens driving device 1 can suppress the secondary resonance in the low frequency band in the tracking direction and improve the sensitivity characteristics.
[0056]
Further, in the objective lens driving device 1, the elastic members 20A to 20D are disposed so as to be inclined with an inclination angle of 45 degrees with respect to a plane parallel to the base member 7 and a plane perpendicular to the plane. By providing the elastic members 20A to 20D, the damping effect by the viscoelastic material can be exhibited simultaneously in both the focusing direction and the tracking direction. Therefore, the objective lens driving device 1 can suppress the secondary resonance and obtain good vibration characteristics and improve the sensitivity characteristics.
[0057]
Furthermore, according to the objective lens driving device 1, the folding direction 29 is formed and the folding direction 29 is provided with the elastic members 20A to 20D to which the viscoelastic materials 50A to 50D for suppressing the resonance are attached. In addition, the secondary resonance with the tracking direction is further suppressed to obtain good vibration characteristics, and it is possible to improve the sensitivity characteristics.
[0058]
The present invention is not limited to the above-described arrangement state of the elastic member, and may be appropriately changed.
[0059]
For example, as shown in FIGS. 8 and 9, the elastic members 20 </ b> A to 20 </ b> D are disposed on the bobbin support member 6 so as to be inclined with respect to a plane parallel to the base member 7 and a plane orthogonal to the plane. It is installed. These elastic members 20 </ b> A to 20 </ b> D are each inclined at an inclination angle of approximately 45 degrees with respect to a plane parallel to the base member 7. These elastic members 20A, 20B and elastic members 20C, 20D are respectively arranged in a cross-sectional C shape opened outward from the bobbin support member 6, as shown in FIG.
[0060]
As shown in FIG. 10, when the objective lens 2 is driven, the elastic members 20A to 20D arranged as described above are respectively displaced in the tracking direction with the turned-up portions 29A to 29D as the fulcrums, respectively. The amount of displacement is increased. Therefore, the elastic member 20 exhibits a damping effect sufficiently and suppresses secondary resonance.
[0061]
Since the basic configuration is almost the same as that of the objective lens driving device 1 described above, common members are denoted by common reference numerals, and detailed description thereof is omitted. In the objective lens driving apparatus configured as shown in FIGS. 8 and 9, the elastic members 20 </ b> A to 20 </ b> D are disposed so as to be inclined with respect to a plane parallel to the base member 7, so that the objective lens 2 is arranged. The displacement amount in the tracking direction when driven is increased, and the damping effect can be sufficiently exhibited. Therefore, this objective lens driving device can suppress the secondary resonance in the low frequency band in the tracking direction and improve the sensitivity characteristics.
[0062]
Further, in the objective lens driving device using the elastic members 20A to 20D, the elastic members 20A to 20D are inclined by 45 degrees symmetrically with respect to a plane parallel to the base member 7 and a plane orthogonal to the plane. By being disposed at an angle, a damping effect can be exhibited simultaneously in both the focusing direction and the tracking direction. Therefore, this objective lens driving device can suppress the secondary resonance to obtain good vibration characteristics and improve the sensitivity characteristics.
[0063]
【The invention's effect】
According to the objective lens driving device and the recording / reproducing apparatus using the same according to the present invention, the objective lens is provided with a plurality of elastic members that are inclined with respect to a plane parallel to the base member. Since the amount of displacement in the tracking direction when driven is increased, the damping effect can be sufficiently exerted. Therefore, this objective lens driving device can suppress the secondary resonance in the low frequency band in the tracking direction and improve the sensitivity characteristics.
[0064]
In addition, the objective lens driving device according to the present invention includes a plurality of elastic members that are disposed so as to be symmetrical with respect to a plane parallel to the base member and a plane orthogonal to the plane. Thus, the damping effect can be exhibited simultaneously in both the focusing direction and the tracking direction. Therefore, this objective lens driving device can suppress the secondary resonance to obtain good vibration characteristics and improve the sensitivity characteristics.
[0065]
Furthermore, according to the objective lens driving device according to the present invention, a folded portion in which at least one folded portion is continuously formed is formed, and a viscoelastic material that suppresses resonance is attached to the folded portion. By providing a plurality of elastic members, the secondary resonance in the focusing direction and the tracking direction can be further suppressed to obtain good vibration characteristics and to improve the sensitivity characteristics.
[Brief description of the drawings]
FIG. 1 is an overall perspective view showing an objective lens driving apparatus according to the present invention.
FIG. 2 is an overall plan view showing the objective lens driving device.
FIG. 3 is an overall side view showing the objective lens driving device.
FIG. 4 is a perspective view showing a part of an elastic member used in the objective lens driving device with a part omitted.
FIG. 5 is a perspective view showing an arrangement state of the elastic member.
FIG. 6 is a front view showing an arrangement state of the elastic member.
FIG. 7 is a plan view showing a displacement state of the elastic member.
FIG. 8 is a plan view showing another example of an elastic member constituting the objective lens driving device according to the present invention.
FIG. 9 is a front view showing an arrangement state of another example of an elastic member.
FIG. 10 is a plan view showing a displacement state of an elastic member of another example.
FIG. 11 is a perspective view showing a conventional objective lens driving device.
FIG. 12 is a perspective view illustrating an arrangement state of elastic members constituting a conventional objective lens driving device.
FIG. 13 is a plan view for explaining an elastic member constituting a conventional objective lens driving device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Objective lens drive device, 2 Objective lens, 5 Bobbin member, 6 Bobbin support member, 7 Base member, 8 Holder part, 9 Magnetic circuit component assembly part, 11 Coil assembly opening part, 12 Focusing coil, 13 Tracking coil, 14 yoke, 15 magnet, 20 (20A to 20D) elastic member, 21 base end portion, 22 elastic deformation portion, 23 fitting portion, 29 folded portion, 50 viscoelastic material

Claims (6)

An objective lens;
Together with the holder unit the objective lens is assembled on one end side is formed, a focusing coil for generating a magnetic driving force acting in a direction parallel to the optical axis of the objective lens at the other end, and the optical axis of the objective lens A bobbin member assembled with a tracking coil that generates a magnetic driving force acting in an orthogonal direction;
The bobbin member is arranged on both side surfaces of the bobbin member so as to be separated from each other in a direction parallel to the optical axis. And a plurality of elastic members that are elastically displaced in the tracking direction,
A magnet is joined and a first yoke inserted inside the focusing coil and a second yoke positioned so as to face the tracking coil are formed to form a magnetic circuit unit, and A base member for fixing and supporting the bobbin support member,
Each of the plurality of elastic members is formed of a leaf spring material, and is formed in a direction orthogonal to the base end portion, a base end portion attached to the bobbin support member, a fitting portion attached to the bobbin member. A folded portion formed by the first folded piece and the second folded piece connected to each other via the connected piece, and the second folded portion between the fitting portion and the second folded piece. An elastically deformable portion formed continuously on the piece, and arranged to be inclined with respect to a plane parallel to the base member,
An objective lens driving device in which a viscoelastic material that suppresses a resonance phenomenon of the elastic member is attached to the folded portion . The plurality of elastic members, and the base member parallel to the plane, the objective lens driving according to claim 1, characterized in that arranged are inclined respectively in plane symmetry with respect to a plane perpendicular to the plane apparatus. The first folded piece and the second folded piece are each formed in a direction parallel to the base end,
  The first folded piece and the base end part are connected via a second connecting piece formed in a direction orthogonal to the base end part to form a second folded part. The objective lens driving device according to claim 1. An objective lens;
Together with the holder unit the objective lens is assembled on one end side is formed, a focusing coil for generating a magnetic driving force acting in a direction parallel to the optical axis of the objective lens at the other end, and the optical axis of the objective lens A bobbin member assembled with a tracking coil that generates a magnetic driving force acting in an orthogonal direction;
The bobbin member is arranged on both side surfaces of the bobbin member so as to be separated from each other in a direction parallel to the optical axis. And a plurality of elastic members that are elastically displaced in the tracking direction,
A magnet is joined and a first yoke inserted inside the focusing coil and a second yoke positioned so as to face the tracking coil are formed to form a magnetic circuit unit, and A base member for fixing and supporting the bobbin support member,
Each of the plurality of elastic members is formed of a leaf spring material, and is formed in a direction orthogonal to the base end portion, a base end portion attached to the bobbin support member, a fitting portion attached to the bobbin member. A folded portion formed by the first folded piece and the second folded piece connected to each other via the connected piece, and the second folded portion between the fitting portion and the second folded piece. An elastically deformable portion formed continuously on the piece, and arranged to be inclined with respect to a plane parallel to the base member,
A recording / reproducing apparatus having an objective lens driving device in which a viscoelastic material for suppressing a resonance phenomenon of the elastic member is attached to the folded portion . The plurality of elastic members, and the base member parallel to the plane, a recording and reproducing apparatus according to claim 4, characterized in that it is arranged to be inclined respectively in plane symmetry with respect to a plane perpendicular to the plane . The first folded piece and the second folded piece are each formed in a direction parallel to the base end,
The first folded piece and the base end part are connected via a second connecting piece formed in a direction orthogonal to the base end part to form a second folded part. The recording / reproducing apparatus according to claim 4 .

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