JP2004266983A - Driving gear and recording and/or reproducing device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a bonding strength between a vibrator and an elastic body, and to improve transfer characteristics of vibrations generated by a vibrating member. <P>SOLUTION: This driving gear is provided with a mounting block 32 on which an optical pickup 8 is mounted, a guide shaft 33 that supports the mounting block 32 movably, and a vibrating member 44. A first electrode 63 and a second electrode 64 are provided on each surface of a piezoelectric element 62 of this vibrating member 44. AC voltages of different phases are impressed to the first electrode 63 and the second electrode 64 to make the piezoelectric element 62 expand and contract. The vibrating member 44 makes a sliding portion 65, which contacts the mounting block 32, move roughly elliptically in such a way that it gets close to and apart from a contact surface 32a of the mounting block 32. The sliding portion 65 is structured by soldering the elastic body 65a on a soldered portion 65c of the piezoelectric element 62. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００４８】
なお、表１におけるＰＺＴは、本例で使用したものであり、線膨張率は、６．７×１０^−６／℃である。表１より明らかなように、モリブデンは、線膨張率が５．１×１０^−６／℃であり、対ＰＺＴ比が−２３．９％であり、タングステンは、線膨張率が４．５×１０^−６／℃であり、対ＰＺＴ比が−３２．８％であり、クロムは、線膨張率が６．５×１０^−６／℃であり、対ＰＺＴ比が−２．９９％であり、コバールは、線膨張率が５．３×１０^−６／℃であり、対ＰＺＴ比が−２０．９％であり、これらの金属は、圧電素子６２にＰＺＴを用いたとき、ＰＺＴの線膨張率の±４０％の範囲にあり、弾性体６５ａとして使用可能である。これに対して、ニッケルは、線膨張率が１３．３×１０^−６／℃であり、対ＰＺＴ比＋９８．５％であり、ＰＺＴの線膨張率の±４０％の範囲から外れ、弾性体６５ａとして使用することはできない。
【００４９】
なお、本例では、圧電素子６２に線膨張率が６．７×１０^−６／℃のＰＺＴに対して線膨張率が５．１×１０^−６／℃であるモリブデンを弾性体６５ａとして用いた。
【００５０】
弾性体６５ａを圧電素子６２に接合するろう付け層６５ｂは、圧電素子６２と弾性体６５ａとの密着性を高め、圧電素子６２に生じた変位を効率良く弾性体６５ａに伝達させる。また、圧電素子６２と弾性体６５ａが温度変化により膨張又は収縮をした場合の接合部の歪みを、ろう材自身の延性で応力緩和し、接合強度の向上を図ると共に接合部の破壊を防止する。
【００５１】
弾性体６５ａにモリブデンを用い、圧電素子６２にＰＺＴを用いたとき、これらの接合に用いるろう材には、銀７２％、銅２０％の銀ろう（ＪＩＳ規格：ＢＡｇ−８）に６％以下のチタンを添加した活性銀ろう材が用いられる。銀ろう材（ＪＩＳ規格：ＢＡｇ−８）は、金属とセラミックとの接合にしばしば用いられるが、ＰＺＴと接合することができず、モリブデンも表面に酸化皮膜があるため接合が困難である。これに対して、チタンを添加した活性化金属ろうは、ろう材中に分布しているチタンが接合界面に集まり、ＰＺＴ中の酸素やモリブデン表面の酸化膜と反応し、接合することができる。チタンの含有量は、６％の範囲内で多い方がよいが、６％を超えると、チタンの偏在が多くなることにより拡散が遅くなり、ろう付け後にろう付け面において銅−チタンの金属間化合物粒子が残留し、ろう付け強度が低下すると共にろう付け強度にばらつきが生じるため、使用することはできない。なお、本例では、Ａｇ：６８％、Ｃｕ：２６％、Ｔｉ：６％の活性銀ろうを用いた。
【００５２】
なお、圧電素子６２のろう付け部６５ｃには、前処理として接合強度を上げるため、フラックスを塗布してもよく、また、金、チタン等の金属スパッタ処理を施してもよく、更に、アルゴンイオンの打ち込み処理を施してもよく、更に、金、銅等の金属箔を拡散接合してもよい。
【００５３】
図７に示すように、弾性体６５ａが接合される部分は、圧電素子６２の取付ブロック３２の接触面３２ａと対向するろう付け部６５ｃである。このろう付け部６５ｃは、取付ブロック３２の接触面３２ａと略平行となすように形成され、Ｄカット形状をしている。弾性体６５ａの接合部となるろう付け部６５ｃは、取付ブロック３２の接触面３２ａと略平行とすることで、ろう付け層６５ｂの厚みを均一にすることができ、弾性体６５ａが図８に示すように傾いた状態でろう付け部６５ｃに接合されることを防止し、接合強度の向上を図り、また、圧電素子６２の変位を効率良く弾性体６５ａに伝達できるようにしている。
【００５４】
なお、弾性体６５ａは、図７に示すように、平坦な部材を用いることで、取付ブロック３２の接触面３２ａとの接触面積を大きくして接触面３２ａとの摩擦力を大きくし、確実に取付ブロック３２を移動することができるように形成されている。勿論、図９に示すように、弾性体６５ａは、ろう付け面側を平坦に形成し、ろう付け部６５ｃと確実に接合できるようにし、接触面３２ａ側を略円弧状に形成するようにしてもよい。
【００５５】
以上のように構成された摺動部６５は、圧電素子６２が径方向に対称及び非対称に変位することで、ろう付け部６５ｃに接合された弾性体６５ａが接触面３２ａに選択的に接触する。すなわち、振動部材４４は、第１の電極６３と第２の電極６４に位相の異なる交流電圧が印加されることで、径方向に対称及び非対称に伸縮し、これにより、摺動部６５は、略楕円軌跡を描くように移動し、取付ブロック３２の接触面３２ａに近接離間する。摺動部６５は、取付ブロック３２の方向に付勢部材４５により付勢された回動部材４３に取り付けられていることで、付勢部材４５の付勢力により圧接される。なお、本発明は、更に、一方の面側の第１及び第２の電極６３，６４と他方の面側の第１及び第２の電極６３，６４に、位相の異なる交流電圧を印加するようにしてもよい。
【００５６】
この振動部材４４の中央部には、図３乃至図５に示すように、取付孔６６ａが形成されており、この取付孔６６ａの周面には、回動部材４３に設けられた取付突部５８に突設された位置決め突起６０，６０が係合される位置決め凹部６６，６６が形成されている。振動部材４４は、取付孔６６ａに、位置決め凹部６６，６６に取付突部５８の位置決め突起６０，６０を係合させるようにして取り付けられ、この後、取付ねじ５９をねじ孔６５に螺合することによって取り付けられる。振動部材４４は、取付突部５８の位置決め突起６０，６０を取付孔６６ａの位置決め凹部６６，６６に係合されることで、振動部材４４が振動した際にも取付突部５８を中心にして回転してしまうことを防止することができ、摺動部６５を常に光ピックアップ８が取り付けられた取付ブロック３２の接触面３２ａに圧接できるようにしている。
【００５７】
ベース４２に取り付けられるローラ４６は、振動部材４４の摺動部６５に対向する位置に取り付けられる。具体的に、ローラ４６は、ローラ４６が回転自在に取り付けられた回転軸となる軸部材６７をベース４２のローラ取付孔５１に取り付けることによってベース４２に固定される。このベース４２に取り付けられたローラ４６は、光ピックアップ８の取付ブロック３２にガイド軸３３，３４と平行となるように設けられたガイド凹部６８内に位置され、ガイド凹部６８の摺動部６５側の面６８ａに点接触する。すなわち、ガイド凹部６８の摺動部６５側の面６８ａに点接触しているローラ４６は、図４及び図１０に示すように、振動部材４４の摺動部６５に対向する位置に設けられることで、付勢部材４５によって図４中矢印Ｄ_１方向に付勢されている回動部材４３に取り付けられた振動部材４４の押圧力を常に複数点ではなく１点で受ける。ローラ４６は、摺動部６５より取付ブロック３２に加えられる押圧力を常に１点で受けるようにすることで、光ピックアップ８を光磁気ディスク３の径方向に送るためのガイド軸３３に、取付ブロック３２のガイド部３８，３９が押圧力を加えないようにし、取付ブロック３２が常に安定してガイド軸３３に沿って移動するようにしている。
【００５８】
ここで、図１１を参照して、振動部材４４の駆動回路７１について説明すると、この駆動回路７１は、振動部材４４の圧電素子６２に供給される交流の駆動電圧を検出する駆動電圧検出部７３と、振動部材４４の圧電素子６２に供給する交流の駆動電圧によって圧電素子６２に流れる交流の駆動電流を検出する駆動電流検出部７４と、駆動電圧検出部７３から出力された電圧検出信号を飽和レベルまで増幅する第１の増幅器７５と、駆動電流検出部７４から出力された電流検出信号を飽和レベルまで増幅する第２の増幅器７６と、飽和レベルにまで増幅された電圧検出信号と電源電圧とを比較して、電圧検出信号のゼロクロス点でオンオフするパルス信号を発生する第１のコンパレータ７７と、飽和レベルにまで増幅された電流検出信号と電源電圧とを比較して、電流検出信号のゼロクロス点でオンオフするパルス信号を発生する第２のコンパレータ７８と、第１のコンパレータ７７から出力されるパルス信号の立ち上がりエッジのタイミングで、トリガパルスを発生する第１のモノマルチバイブレータ７９と、第２のコンパレータ７８から出力されるパルス信号の立ち上がりエッジのタイミングで、トリガパルスを発生する第２のモノマルチバイブレータ８０と、電圧位相トリガパルスと電流位相トリガパルスとの位相差に応じた時間幅のパルス信号を発生するＲＳフリップフロップ回路８１と、ＲＳフリップフロップ回路８１から出力されたパルス信号を積分して平滑化し、後段のＶＣＯ８３に供給するアナログの制御電圧を生成する積分回路８２と、入力されたアナログの制御電圧に応じて周波数を変化させたクロック信号を発生するＶＣＯ（Ｖｏｌｔａｇｅ Ｃｏｎｔｒｏｌｌｅｄ Ｏｓｃｉｌｌａｔｏｒ）８３と、ＶＣＯ８３が出力するクロック信号の周波数の１／ｎの周波数の正弦波信号を生成する第１の波形発生部８４と、第１の波形発生部８４から出力されたアナログ信号に対して、同一周期であって９０°位相がずれた余弦波信号を生成する第２の波形発生部８５と、第１の波形発生部８４から出力された正弦波信号を電力増幅し、振動部材４４の圧電素子６２に供給する第１のパワーアンプ８６と、第２の波形発生部８５から出力された余弦波信号を電力増幅し、振動部材４４の圧電素子６２に供給する第２のパワーアンプ８７と、駆動電流検出部７４により検出された検出信号をピークホールドし、そのピーク値を検出するピークホールド回路８８と、ピークホールド回路８８から供給されたピーク値と、速度制御のための基準電圧とを比較し、その誤差信号に応じて、上記第１のパワーアンプ８６及び第２のパワーアンプ８７を制御して、駆動電圧を可変するゲイン制御回路８９とを備える。
【００５９】
駆動電圧検出部７３は、振動部材４４の圧電素子６２に供給される交流の駆動電圧を検出し、検出した駆動電圧に応じた電圧検出信号を第１の増幅器７５に出力する。駆動電流検出部７４は、振動部材４４の圧電素子６２に供給する交流の駆動電圧によって、この圧電素子６２に流れる交流の駆動電流を検出し、検出した駆動電流に応じた電流検出信号を第２の増幅器７６に出力する。
【００６０】
第１の増幅器７５は、駆動電圧検出部７３から出力された電圧検出信号を飽和レベルまで増幅し、第１のコンパレータ７７に供給する。第１のコンパレータ７７は、飽和レベルにまで増幅された電圧検出信号と電源電圧とを比較して、電圧検出信号のゼロクロス点でオンオフするパルス信号を発生する。第１のコンパレータ７７から出力されるパルス信号は、第１のモノマルチバイブレータ７９に供給される。
【００６１】
第２の増幅器７６は、駆動電流検出部７４から出力された電流検出信号を飽和レベルまで増幅し、第２のコンパレータ７８に供給する。第２のコンパレータ７８は、飽和レベルにまで増幅された電流検出信号と電源電圧とを比較して、電流検出信号のゼロクロス点でオンオフするパルス信号を発生する。第２のコンパレータ７８から出力されるパルス信号は、第２のモノマルチバイブレータ８０に供給される。
【００６２】
第１のモノマルチバイブレータ７９は、第１のコンパレータ７７から出力されるパルス信号の立ち上がりエッジのタイミングで、トリガパルスを発生する。このトリガパルスは、圧電素子６２に供給される駆動電圧の位相を表すトリガパルスであり（以下、電圧位相トリガパルスという。）、第１のモノマルチバイブレータ７９から出力された電圧位相トリガパルスは、ＲＳフリップフロップ回路８１に供給される。第２のモノマルチバイブレータ８０は、第２のコンパレータ７８から出力されるパルス信号の立ち上がりエッジのタイミングで、トリガパルスを発生する。このトリガパルスは、圧電素子６２に供給される駆動電流の位相を表すトリガパルスであり（以下、電流位相トリガパルスという。）、第２のモノマルチバイブレータ８０から出力された電流位相トリガパルスは、ＲＳフリップフロップ回路８１に供給される。
【００６３】
ＲＳフリップフロップ回路８１は、電圧位相トリガパルスと電流位相トリガパルスとの位相差に応じた時間幅のパルス信号を発生する。ＲＳフリップフロップ回路８１は、電圧位相トリガパルスが供給されたタイミングでオンとなり、電流位相トリガパルスが供給されたタイミングでオフとなるパルスを積分回路８２に出力する。ＲＳフリップフロップ回路８１は、電圧位相トリガパルスと電流位相トリガパルスとのタイミングが一致するとき、すなわち、圧電素子６２に供給される駆動電圧と圧電素子６２に流れる駆動電流との位相差が０のときに、所定の時間幅のパルスが出力されるようにする。この所定の時間幅は、後段の積分回路８２で積分をしたときに基準電圧Ｖｒｅｆが出力される時間幅である。
【００６４】
積分回路８２は、ＲＳフリップフロップ回路８１から出力されたパルス信号を積分し、後段のＶＣＯ８３に供給するアナログの制御電圧を生成する。ＶＣＯ８３は、入力されたアナログの制御電圧に応じて周波数を変化させたクロック信号を発生する。ＶＣＯ８３の中心周波数は、振動部材４４の圧電素子６２の共振周波数ｆ０のｎ倍の周波数のクロック信号を発生する（例えば、ｎ＝９０）。ＶＣＯ８３は、出力するクロック信号の中心周波数ｎ・ｆ０を中心として、下限周波数ｆ１のｎ倍の周波数から、上限周波数ｆ２のｎ倍の周波数までの範囲で変動させる。下限周波数ｆ１及び上限周波数ｆ２は、共振周波数ｆ０で得られる振幅値から３ｄＢ下がった点の周波数である。ＶＣＯ８３は、この制御電圧に応じて周波数が制御されたクロック信号を、第１の波形発生部８４及び第２の波形発生部８５に供給する。
【００６５】
第１の波形発生部８４は、正弦波の１波長分の振幅データを、０〜（ｎ−１）までのアドレスに対応させて記憶している。具体的には、正弦波の１波長をｎ分割してサンプリングして、そのサンプリングした値を０〜（ｎ−１）のアドレスに対応させて記憶している。第１の波形発生部８４は、ＶＣＯ８３から供給されたクロックにより、０〜（ｎ−１）の値を周期的にカウントしていき、カウントした値のアドレスの振幅データを読み出す。そして、第１の波形発生部８４は、読み出した振幅データを、ディジタル信号からアナログ信号に変換してアナログ信号を第ｌのパワーアンプ８６に出力する。このように第１の波形発生部８４から出力されたアナログ信号は、共振周波数ｆ０を中心として、下限周波数ｆ１から上限周波数ｆ２まで変動する。
【００６６】
第２の波形発生部８５は、上記第１の波形発生部８４に記憶されている正弦波に対して９０°位相がずれた余弦波の１波長分の振幅データを、０〜（ｎ−１）までのアドレスに対応させて記憶している。具体的には、余弦波の１波長をｎ分割してサンプリングして、そのサンプリングした値を０〜（ｎ−１）のアドレスに対応させて記憶している。第２の波形発生部８５は、ＶＣＯ８３から供給されたクロックにより、０〜（ｎ−１）の値を周期的にカウントしていき、カウントした値のアドレスの振幅データを読み出す。そして、第２の波形発生部８５は、読み出した振幅データを、ディジタル信号からアナログ信号に変換してアナログ信号を出力する。このように第２の波形発生部８５から出力されたアナログ信号は、上記第１の波形発生部８４から出力されたアナログ信号に対して、同一周期であって９０°位相がずれた余弦波信号となる。
【００６７】
第ｌのパワーアンプ８６は、第１の波形発生部８４から出力された正弦波信号を電力増幅し、振動部材４４の圧電素子６２に設けられた第１の電極６３に供給する。そして、この第１のパワーアンプ８６から振動部材４４に印加される駆動電圧が上記駆動電圧検出部７３により検出され、この第１のパワーアンプ８６から圧電素子６２に供給される駆動電流が上記電流検出部７４により検出されることになる。第２のパワーアンプ８７は、第２の波形発生部８５から出力された余弦波信号を電力増幅し、圧電素子６２に設けられ第２の電極６４に供給する。
【００６８】
ピークホールド回路８８は、駆動電流検出部７４により検出された検出信号をピークホールドし、そのピーク値を検出する。ピークホールド回路８８は、検出したピーク値をゲイン制御回路８９に供給する。ゲイン制御回路８９は、ピークホールド回路８８から供給されたピーク値と、速度制御のための基準電圧とを比較し、その誤差信号に応じて、上記第１のパワーアンプ８６及び第２のパワーアンプ８７を制御して、駆動電圧を可変する。
【００６９】
以上のように構成された駆動回路７１の動作について説明すると、先ず、駆動電圧検出部７３が振動部材４４に印加された駆動電圧を検出して、正弦波の電圧検出信号を出力する。この電圧検出信号を第１の増幅器７５により飽和増幅して、第１のコンパレータ７７によりゼロクロス点を示すパルス信号に変換する。そして、第１のモノマルチバイブレータ７９が、ゼロクロス点の立ち上がりエッジのタイミングで発生する電圧位相トリガパルスを出力する。
【００７０】
また、駆動電流検出部７４が振動部材４４に流れる駆動電流を検出して、正弦波の電流検出信号を出力する。この電流検出信号を第２の増幅器７６及び第２のコンパレータ７８により飽和増幅して、ゼロクロス点を示すパルス信号に変換する。そして、第２のモノマルチバイブレータ８０が、ゼロクロス点の立ち上がりエッジのタイミングで発生する電流位相トリガパルスを出力する。
【００７１】
電圧位相トリガパルスと電流位相トリガパルスは、両者ともフリップフロップ回路８１に供給され、このフリップフロップ回路８１で、位相差が求められる。求められた位相差は、積分回路８２により平滑化され、アナログの制御電圧として、ＶＣＯ８３に供給される。この積分回路８２は、位相差が０のときに基準電圧Ｖｒｅｆを出力し、このＶｒｅｆを中心として増減するアナログの制御電圧を出力する。
【００７２】
ＶＣＯ８３から出力されるクロック信号は、入力電圧がＶｒｅｆ（位相差が０）のときに共振周波数ｆ０のｎ倍の中心周波数とされ、その周波数が入力電圧の変動に応じてｎ・ｆ１〜ｎ・ｆ２の範囲で可変される。そして、第１のパワーアンプ８６からは、その周波数が入力電圧の変動に応じてｆ１〜ｆ２の範囲で可変され、電流との位相差が０となる周波数でロックされる駆動電圧が振動部材４４の圧電素子６２に供給される。すなわち、振動部材４４の第１の電極６３には、図１２（Ａ）に示すように、以上のような駆動回路７１により正弦信号が印加され、第２の電極６４には、図１２（Ｂ）に示すように、位相がπ／２ずらされた余弦信号が印加される。
【００７３】
例えば、振動部材４４の横（Ｘ）方向、すなわち光ピックアップ８が取り付けられた取付ブロック３２の送り方向は、第１の電極６３に印加される正弦信号に応じて伸縮し、振動部材４４の縦（Ｙ）方向、すなわち取付ブロック３２の接触面３２ａに対して近接離間する方向は、第２の電極６４に印加される余弦信号に応じて伸縮する。そして、圧電素子６２は、各電極６３，６４にプラスの電圧が印加されたとき、プラスの電極６３，６４が設けられた側が伸長し、各電極６３，６４にマイナスの電圧が印加されたとき、マイナスの電極６３，６４が設けられた側が収縮する。すると、図１２（Ｃ）に示すように、摺動部６５は、光ピックアップ８が取り付けられた取付ブロック３２の接触面３２ａに近接離間する方向に移動しながら、取付ブロック３２の移動方向に移動する。すなわち、図１２（Ｄ）に示すように、振動部材４４に設けられた摺動部６５は、略楕円の軌跡を描くように移動し、取付ブロック３２の接触面３２ａに近接する方向に移動するとき、取付ブロック３２の進行方向に移動し、取付ブロック３２の接触面３２ａに離間する方向に移動するとき、進行方向と逆方向に移動する。
【００７４】
図１０を用いて、以上のような駆動装置４１の動作について説明すると、例えば、光ピックアップ８の取り付けられた取付ブロック３２を光磁気ディスク３の内周側に移動させるとき、すなわち図１０中矢印Ｄ_２方向に移動させるとき、第１の電極６３には、図１２（Ａ）に示すような正弦信号が印加され、第２の電極６４には、図１２（Ｂ）に示すような余弦信号が印加される。すると、取付ブロック３２の接触面３２ａに接触する摺動部６５は、図１２（Ｃ）に示すように、取付ブロック３２の接触面３２ａに対して近接離間し、図１２（Ｄ）中の矢印の示す方向に略楕円軌跡を描くように移動する。すなわち、摺動部６５は、取付ブロック３２の接触面３２ａに近接する方向に移動するとき、取付ブロック３２を図１０中矢印Ｄ_２方向に押し進め、取付ブロック３２の接触面３２ａから離間する方向に移動するとき、次に取付ブロック３２を進行方向に押し進めるため、元の位置に戻る方向に移動する。これにより、振動部材４４は、摺動部６５を略楕円軌跡を描くように一方向に移動させ、取付ブロック３２の接触面３２ａに対して近接離間し、接触面３２ａに近接しているとき、取付ブロック３２を摺動部６５の進行方向に押し進め、取付ブロック３２を図１０中矢印Ｄ_２方向に移動させる。
【００７５】
詳細は省略するが、取付ブロック３２を、光磁気ディスク３の外周側、すなわち図１０中反矢印Ｄ_２方向に移動するときには、第１の電極６３に上述の例に対して逆の正弦信号を印加するようにし、第２の電極６４に上述の例に対して逆の余弦信号を印加すればよい。これによって、摺動部６５は、取付ブロック３２の接触面３２ａに対して近接離間し、図１２（Ｄ）中の矢印とは反対方向に略楕円軌跡を描くように移動する。これにより、振動部材４４は、摺動部６５を略楕円軌跡を描くように他方向に移動させ、取付ブロック３２の接触面３２ａに対して近接離間し、接触面３２ａに近接しているとき、取付ブロック３２を摺動部６５の進行方向に押し進め、取付ブロック３２を図１０中反矢印Ｄ_２方向に移動させる。
【００７６】
以上のような駆動装置４１では、図１０に示すように、取付ブロック３２の位置に拘わらず、すなわち取付ブロック３２が光磁気ディスクの内周側や外周側に移動して中央位置から変位した位置に移動しても、常に振動部材４４により取付ブロック３２に加えられる押圧力をローラ４６で１点で受けることから、光ピックアップ８を光磁気ディスク３の径方向に送るためのガイド軸３３に、取付ブロック３２のガイド部３８，３９が押圧力を加えないようにし、取付ブロック３２が常に安定してガイド軸３３に沿って移動するようにしている。すなわち、この駆動装置４１では、ガイド軸３３とガイド部３８，３９との摩擦抵抗に関係なく、円滑に取付ブロック３２をガイド軸３３，３４に沿って移動させることができる。
【００７７】
また、振動部材４４を構成する圧電素子６２の摺動部６５を構成する弾性体６５ａは、圧電素子６２と略同じ線膨張率の材料が選択され、圧電素子６２にろう付けされていることから、温度変化によって圧電素子６２と弾性体６５ａとが収縮したり膨張したときにも、接合部において歪みが発生することを防止し、弾性体６５ａと圧電素子６２との接合が破壊され、圧電素子６２より剥がれることを防止することができる。また、弾性体６５ａは、圧電素子６２のろう付け部６５ｃにろう付けされることで、ろう材自身の延性で応力緩和し、接合強度の向上を図ると共に接合部の破壊を防止することができる。更に、弾性体６５ａは、圧電素子６２にろう付けされることで、圧電素子６２との密着性が高められ、圧電素子６２に生じた変位が効率良く伝達されるようになり、光ピックアップ８の位置制御を正確に行うことができる。
【００７８】
次に、以上のような駆動装置４１を備えるディスク記録再生装置１の回路構成について、図１３を参照して説明すると、このディスク記録再生装置１は、光ピックアップ８からの出力よりＲＦ信号等各種信号を生成するＲＦアンプ１０１と、光ピックアップ８、スピンドルモータ１２等を駆動するドライバ１０２と、スピンドルモータ１２等のサーボ信号を生成するサーボ回路１０３と、ディジタル信号処理を行うディジタルシグナルプロセッサ（以下、ＤＳＰという。）１０４と、ディジタル信号をアナログ信号に変換するディジタル／アナログ変換器（以下、単にＤ／Ａ変換器という。）１０５と、アナログ信号をディジタル信号に変換するアナログ／ディジタル変換器（以下、Ａ／Ｄ変換器という。）１０６と、ディジタル信号の入出力を行うディジタルインターフェース１０７と、Ｄ−ＲＡＭ（Ｄｙｎａｍｉｃ Ｒａｎｄｏｍ Ａｃｃｅｓｓ Ｍｅｍｏｒｙ）により構成されたバッファメモリ１０８と、磁気ヘッド１５の駆動制御を行うヘッド駆動回路１０９と、ユーザが操作を行う操作部１１０と、ユーザへの表示を行う表示部１１１と、システム全体を制御するシステムコントローラ１１２とを備える。
【００７９】
ＲＦアンプ１０１は、光ピックアップ８を構成する光検出器からの出力信号に基づいて、ＲＦ信号、フォーカシングエラー信号及びトラッキングエラー信号を生成する。また、ＲＦアンプ１０１は、光磁気ディスク３にウォブリンググルーブとして記録された絶対位置情報であるグルーブ情報信号を抽出する。例えばフォーカシングエラー信号は、非点収差法等により生成され、トラッキングエラー信号は、３ビーム法、プッシュプル法等により生成される。そして、ＲＦアンプ１０１は、ＲＦ信号及びグルーブ情報信号をＤＳＰ１０４に出力し、フォーカシングエラー信号及びトラッキングエラー信号をサーボ回路１０３に出力する。
【００８０】
サーボ回路１０３は、ＲＦアンプ１０１から供給されるフォーカシングエラー信号に基づくフォーカシングサーボ制御、トラッキングエラー信号、システムコントローラ１１２からのトラックジャンプ指令やアクセス指令等に基づいた駆動装置４１やスピンドルモータ１２のサーボ制御等を行う。
【００８１】
具体的に、このサーボ回路１０３は、ＲＦアンプ１０１から供給されたフォーカシングエラー信号から、フォーカシング方向の目標値との誤差量を検出し、この検出結果に基づいたサーボ信号をドライバ１０２に出力する。ドライバ１０２は、このフォーカシングサーボ信号に応じた駆動電流を光ピックアップ８の対物レンズ駆動機構のフォーカシングコイルに出力することにより、対物レンズ１４を光磁気ディスク３の信号記録面に対して近接離間するフォーカシング方向に駆動変位させる。
【００８２】
このサーボ回路１０３は、トラッキングエラー信号、システムコントローラ１１２からのトラックジャンプ指令やアクセス指令等に基づいた駆動装置４１の制御を行う。また、このサーボ回路１０３は、ドライバ１０２を介してスピンドルモータ１２を光磁気ディスク３を角速度一定又は線速度一定回転するように駆動すると共に、システムコントローラ１１２からの指令に基づいた制御信号をドライバ１０２に供給することによって、スピンドルモータ１２の駆動又は停止の制御を行う。また、このサーボ回路１０３は、システムコントローラ１１２からの指令に基づいた制御信号をドライバ１０２に供給することによって、光ピックアップ８における半導体レーザの点灯又は消灯、並びにレーザ出力等の駆動制御を行う。
【００８３】
ＤＳＰ１０４は、ＲＦアンプ１０１からグルーブ情報信号が供給されるアドレスデコーダ１１３を有している。このアドレスデコーダ１１３は、ＲＦアンプ１０１から供給されたグルーブ情報信号をデコードしてアドレス情報を抽出する。このアドレス情報は、システムコントローラ１１２に供給され、各種の駆動制御に用いられる。また、ＤＳＰ１０４は、ＥＦＭ／ＣＩＲＣエンコーダ／デコーダ１１４と、耐振用メモリコントローラ１１５と、圧縮エンコーダ／デコーダ１１６とを有している。
【００８４】
ＥＦＭ／ＣＩＲＣエンコーダ／デコーダ１１４は、光磁気ディスク３に記録されたデータの再生をするとき、ＲＦアンプ１０１から入力されたＲＦ信号に対して、ＥＦＭ（Ｅｉｇｈｔ ｔｏ Ｆｏｕｒｔｅｅｎ Ｍｏｄｕｌａｔｉｏｎ）復調等の復調処理やＣＩＲＣ（Ｃｒｏｓｓ Ｉｎｔｅｒｌｅａｖｅ Ｒｅｅｄ−Ｓｏｌｏｍｏｎ Ｃｏｄｅ）等のエラー訂正復号処理を行う。また、光磁気ディスク３にデータを記録するとき、耐振用メモリコントローラ１１５の制御によってバッファメモリ１０８に一時的に記録されたデータが所定のデータ単位で入力され、入力されたデータに対してＣＩＲＣ等のエラー訂正符号化処理を施すと共に、ＥＦＭ等の変調処理を施し、ヘッド駆動回路１０９へ出力する。
【００８５】
耐振用メモリコントローラ１１５は、Ｄ−ＲＡＭ（Ｄｙｎａｍｉｃ−Ｒａｎｄｏｍ Ａｃｃｅｓｓ Ｍｅｍｏｒｙ ）等のバッファメモリ１０８へのデータの書き込みやバッファメモリ１０８からのデータの読み出しを制御する。具体的に、耐振用メモリコントローラ１１５は、光磁気ディスク３に記録されているデータの再生をするとき、ＥＦＭ／ＣＩＲＣエンコーダ／デコーダ１１４から出力されたデータをバッファメモリ１０８に書き込み、この後、所定データ単位でデータを読み出し、読み出したデータを圧縮エンコーダ／デコーダ１１６に出力する。また、耐振用メモリコントローラ１１５は、光磁気ディスク３にデータを記録するとき、圧縮エンコーダ／デコーダ１１６より入力されたデータをバッファメモリ１０８に書き込み、この後、所定データ単位でデータを読み出し、読み出したデータをＥＦＭ／ＣＩＲＣエンコーダ／デコーダ１１４へ出力する。
【００８６】
圧縮エンコーダ／デコーダ１１６は、オーディオデータ等のデータの圧縮伸長を行う。具体的に、圧縮エンコーダ／デコーダ１１６は、光磁気ディスク３に記録されているデータの再生をするとき、バッファメモリ１０８から読み出されたＡＴＲＡＣ（Ａｄａｐｔｉｖｅ Ｔｒａｎｓｆｏｒｍ Ａｃｏｕｓｔｉｃ Ｃｏｄｉｎｇ）等の方式で圧縮されているデータの伸長処理を行い、Ｄ／Ａコンバータ１０５又はディジタルインターフェース１０７に出力する。また、圧縮エンコーダ／デコーダ１１６は、光磁気ディスク３にデータを記録するとき、ディジタルインターフェース１０７又はＡ／Ｄ変換器１０６からのディジタルデータの圧縮処理をし、圧縮したデータをバッファメモリ１０８に出力する。
【００８７】
ヘッド駆動回路１０９は、ＥＦＭ／ＣＩＲＣエンコーダ／デコーダ１１４でエラー訂正符号化処理や変調処理が施された記録データに応じて外部磁界を磁気ヘッド１５に発生させる。このとき、ヘッド昇降機構は、システムコントローラ１１２からの指令の基づいて、磁気ヘッド１５を光磁気ディスク３の光ピックアップ８と対向する面とは反対側の面に接触又は近接させる。光磁気ディスク３は、光磁気記録層に光ピックアップ８により光ビームが照射されてキュリー温度以上に加熱され磁気ヘッド１５により磁界が印加されることによってデータが記録される。
【００８８】
操作部１１０は、操作スイッチや操作釦等から構成されており、例えば再生、録音、一時停止、停止、早送り、早戻し、頭出しサーチ等の記録又は再生動作にかかる操作情報や、通常再生、プログラム再生、シャッフル再生等のプレイモードにかかる操作情報をシステムコントローラ１１２に供給する。表示部１１１は、液晶表示パネル等から構成されており、記録又は再生時における光磁気ディスク３の動作モード状態や、トラックナンバ、記録時間又は再生時間、編集動作状態等を表示する。システムコントローラ１１２は、操作部１１０から供給された操作情報に応じた各部の動作制御を実行する。
【００８９】
次に、以上のように構成されたディスク記録再生装置１の動作について説明する。
【００９０】
先ず、ディスク記録再生装置１を構成する装置本体に対して蓋体が内部を開放する方向に回動され、装置本体内に構成された装着部１０ａが開放された状態において、ディスクカートリッジ２は、図１に示すように、シャッタ部材５が設けられた前面部に直交する一側面部を挿入端として、装置本体内に挿入される。すると、ディスクカートリッジ２は、蓋体と連動したカートリッジホルダ１１に保持される。このとき、シャッタ部材５は、カートリッジホルダに設けられたシャッタ開放片２４によってシャッタロックが解除され、カートリッジ本体２ｃの前面部に沿ってスライドされ、カートリッジ本体２ｃに設けられた開口部４，４を開放し、光磁気ディスク３の信号記録領域を内外周に亘ってカートリッジ本体２ｃの外部に臨ませる。
【００９１】
装置本体の内部を開放した状態にある蓋体を、装置本体の内部を閉塞する方向に回動操作すると、カートリッジホルダ１１に保持されたディスクカートリッジ２は、シャーシ１０に構成された装着部１０ａに装着される。すると、カートリッジ本体２ｃの下ハーフ２ｂ側略中央部に設けられた駆動用の開口部６からは、ディスク回転駆動機構７を構成するディスクテーブル１３が内部に進入する。そして、ディスクテーブル１３は、光磁気ディスク３に設けられているクランピングプレート３ａを磁気吸引し、光磁気ディスク３のセンタ孔に係合し、光磁気ディスク３のセンタリングを図り、光磁気ディスク３を回転可能な状態にする。
【００９２】
次に、シャーシ１０の装着部１０ａに装着されたディスクカートリッジ２の光磁気ディスク３にデータを記録する場合について説明する。先ず、ユーザによって操作部１１０を構成する記録開始釦が押されると、記録開始信号がシステムコントローラ１１２に入力される。すると、システムコントローラ１１２は、スピンドルモータ１２を駆動し光磁気ディスク３を線速度又は角速度一定で回転する。これと共に、光ピックアップ８を構成する半導体レーザが駆動され、データ読み出し用の出力レベルで光ビームが出射される。
【００９３】
また、光ピックアップ送り機構３１の駆動装置４１が駆動回路７１により駆動される。具体的に、駆動回路７１は、図１２（Ａ）に示すような正弦信号を振動部材４４を構成する圧電素子６２に設けられた第１の電極６３に印加すると共に、第２の電極６４に図１２（Ｂ）に示すような第１の電極６３に印加する正弦信号に対して位相をπ／２ずらして生成された余弦信号を印加する。すると、振動部材４４の摺動部６５は、図１２（Ｃ）及び図１２（Ｄ）に示すように、略楕円軌跡を描くように移動する。これにより、摺動部６５は、取付ブロック３２の接触面３２ａに近接する方向に移動するとき、取付ブロック３２を図１０中矢印Ｄ_２方向に押し進め、取付ブロック３２の接触面３２ａから離間する方向に移動するとき、次に取付ブロック３２を進行方向に押し進めるため、元の位置に戻る方向に移動する。振動部材４４は、この動作を繰り返すことにより、光ピックアップ８の取り付けられた取付ブロック３２を光磁気ディスク３の径方向に移動する。これによって、光ピックアップ８は、光磁気ディスク３の内周側に移動され、対物レンズ駆動機構がフォーカシングサーボ信号に基づいてフォーカシングサーボ制御を行い、記録位置を特定するためアドレスデータの読み出しを開始する。すなわち、アドレスデコーダ１１３は、ＲＦアンプ１０１から入力されたグルーブ情報信号よりアドレス情報を生成し、生成したアドレス情報をシステムコントローラ１１５に出力する。
【００９４】
システムコントローラ１１５がアドレスデコーダ１１３から入力されたアドレス情報に基づいて記録データの記録位置を特定すると、磁気ヘッド１５は、昇降操作部材２７が回動されることによって、光磁気ディスク３に近接される。これと共に、光ピックアップ８の半導体レーザは、データ記録用の出力レベルで光ビームを出射する。光磁気ディスク３は、光ピックアップ８により光ビームが照射されてキュリー温度以上に加熱されると共に、磁気ヘッド１５により磁界が印加されることによってデータの記録が開始される。
【００９５】
このとき、光ピックアップ送り機構３１を構成する駆動装置４１の駆動回路７１には、ドライバ１０２よりシステムコントローラ１１２からのトラックジャンプ等の制御信号に応じたスレッド信号と対物レンズのトラッキングエラー信号に応じた駆動信号が入力される。駆動回路７１は、スレッド信号とトラキングサーボ信号に基づいて生成された駆動信号に基づいて、上述のように光ピックアップ８を光磁気ディスク３の径方向に移動させると共に、光磁気ディスク３の記録トラックに対して直交する方向に移動させ、対物レンズ１４のトラッキング制御を行う。すなわち、光ピックアップ送り機構３１は、超音波振動を発生する駆動装置４１を用いることで、微細な対物レンズ１４のトラッキング制御とトラッキング制御に対して大まかな光ピックアップ８の光磁気ディスク３の径方向の送り操作とを行う。
【００９６】
光磁気ディスク３に記録する記録データは、アナログ信号であるときＡ／Ｄ変換器１０６によってディジタル信号に変換され、また、ディジタル信号であるとき、ディジタルインターフェース１０７を介してディジタル入力端子１２０から入力される。そして、ディジタル信号の記録データは、この後、圧縮エンコーダ／デコーダ１１６でＡＴＲＡＣにより圧縮され、耐振用メモリコントローラ１１５によってバッファメモリ１０８へ一時的に書き込まれ、このバッファメモリ１０８より所定のデータ単位毎に読み出されて、ＥＦＭ／ＣＩＲＣエンコーダ／デコーダ１１４でＥＦＭ変調、並びにエラー訂正に関するＣＩＲＣ等のエンコード処理が行われた後に、ヘッド駆動回路１０９へと供給される。そして、ヘッド駆動回路１０９は、記録データに応じて変調された外部磁界を磁気ヘッド１５に発生させる。磁気ヘッド１５は、光ピックアップ８により光ビームが照射されキュリー温度以上に加熱された位置に外部磁界を印加してデータを記録する。
【００９７】
次に、ディスクカートリッジ２の光磁気ディスク３に記録されているデータの再生を行うときについて説明する。ユーザによって操作部１１０を構成する再生開始釦が押されると、再生開始信号がシステムコントローラ１１２に入力され、システムコントローラ１１２は、これを、サーボ回路１０３に出力する。なお、再生時のサーボ回路１０３の動作は、記録時とほぼ同様なため詳細は省略するが、再生時には、磁界を光磁気ディスク３に印加する必要がないことから、ヘッド昇降機構により光磁気ディスク３に対して離間した状態にされる。また、光ピックアップ８の半導体レーザは、データ読み出し用の出力レベルの光ビームを出射する。
【００９８】
光ピックアップ８が光磁気ディスク３に光ビームを照射し、反射された戻りの光ビームを検出すると、再生データは、ＥＦＭ／ＣＩＲＣエンコーダ／デコーダ１１４でＥＦＭ復調、並びにＣＩＲＣ等のエラー訂正復号化処理が行われ、耐振用メモリコントローラ１１５によってバッファメモリ１０８へと書き込まれる。バッファメモリ１０８に一旦書き込まれた再生データは、所定のデータ単位毎に読み出されて、圧縮エンコーダ／デコーダ１１６に供給され、ＡＴＲＡＣによるデコード処理が行われ伸長される。この伸長された再生データは、Ｄ／Ａ変換器１０５によってアナログ信号に変換された後に、オーディオ出力端子１１７に接続されたスピーカ、イヤホン、ヘッドフォン等の電気音響変換器から可聴音に変換されて出力される。また、このディジタル信号は、ディジタルインターフェース１０７を介して、ディジタル出力端子１１９から直接出力される。
【００９９】
以上のように構成されるディスク記録再生装置１では、光ピックアップ８の送り送り機構３１に、超音波振動をする振動部材４４を用いた駆動装置４１を用いるので従来のような駆動モータによる回転駆動をギヤ群及びラック部材を介して直線駆動に変換する機構に比べて、部品点数を大幅に削減することができ、更なる小型化及び軽量化を図ることができる。また、駆動装置４１は、光ピックアップ８の位置を保持するのに電力を必要としないことから省電力化を図ることができる。更に、駆動装置４１は、マグネット等を使用せず磁場を発生させないことから、磁気ヘッド１５との干渉を無くすことができる。更に、ディスク記録再生装置１は、駆動装置４１で対物レンズ１４のトラッキング制御と光ピックアップ８の送り操作を行うことができ、光ピックアップ８の対物レンズ駆動機構にトラッキング制御用のコイルやマグネットを設ける必要がなくなり構成の簡素化及び小型化を図ることができる。
【０１００】
また、図７及び図９に示すように、振動部材４４を構成する圧電素子６２の摺動部６５を構成する弾性体６５ａは、圧電素子６２と略同じ線膨張率の材料が選択され、圧電素子６２にろう付けされていることから、温度変化によって圧電素子６２と弾性体６５ａとが収縮したり膨張したときにも、接合部において歪みが発生することを防止し、弾性体６５ａと圧電素子６２との接合が破壊され、圧電素子６２より剥がれることを防止することができる。また、弾性体６５ａは、圧電素子６２のろう付け部６５ｃにろう付けされることで、ろう材自身の延性で応力を緩和し、接合強度の向上を図ると共に接合部の破壊を防止することができる。更に、弾性体６５ａは、圧電素子６２にろう付けされることで、圧電素子６２との密着性が高められ、圧電素子６２に生じた変位が効率良く伝達される。したがって、駆動装置４１は、装置全体の小型化を図りつつ、トラッキング制御等の取付ブロック３２の微小な移動制御も正確に行うことができ、データの記録再生を確実に行うことができる。また、圧電素子６２の変位を弾性体６５ａを介して効率良く取付ブロック３２の接触面３２ａに伝達することができることから、省電力化を図ることができる。
【０１０１】
なお、上述した駆動装置４１は、この他に次のような構成としてもよい。すなわち、上述の例では、振動部材４４を回動部材４３に取り付け、回動部材４３を付勢部材４５により図５中矢印Ｄ_１方向に付勢する振動装置４１を説明したが、本発明では、図１４及び図１５に示すように、振動部材４４を光ピックアップ８が取り付けられた取付ブロック３２の接触面３２ａに直線的に押圧するようにしてもよい。
【０１０２】
この駆動装置１４１は、上述の駆動装置４１と同様に、光ピックアップ８が取り付けられる取付ブロック３２をガイド軸３３，３４に沿って光磁気ディスク３の径方向に移動するものであって、ディスク記録再生装置１のシャーシ１０に取り付けられるベース１４２と、ベース１４２に対して直線移動可能に配設され、振動部材４４の押圧力を受けるローラ４６が取り付けられるローラ取付板１４３と、ローラ取付板１４３に対して直線移動可能に配設され、振動部材４４が取り付けられる振動部材取付板１４４と、ローラ取付板１４３と振動部材取付板１４４との間に配設される付勢部材１４５，１４５とを備える。
【０１０３】
ベース１４２は、ディスク記録再生装置１のシャーシ１０の裏面に取り付けられるものであって、このベース１４２には、ローラ４６が取り付けられるローラ取付板１４３が光ピックアップ８が取り付けられる取付ブロック３２に対して近接離間する方向、すなわち図１４及び図１５中矢印Ｄ_３方向及び反矢印Ｄ_３方向に移動可能に取り付けられる。ベース１４２には、ローラ取付板１４３の図１４及び図１５中矢印Ｄ_３方向及び反矢印Ｄ_３方向に移動をガイドする一対のガイド部１４６，１４６が設けられており、一対のガイド部１４６，１４６には、ローラ取付板１４３の図１４及び図１５中矢印Ｄ_３方向及び反矢印Ｄ_３方向の側縁部が係合される。また、ベース１４２には、ローラ取付板１４３の図１４及び図１５中反矢印Ｄ_３方向の移動を規制するストッパ１４７が立設されている。
【０１０４】
ベース１４２に直線移動可能に取り付けられるローラ取付板１４３は、一端部に、振動部材４４の摺動部６５と対向してローラ４６を配設するためのローラ取付孔１４８が形成されている。ローラ４６は、ローラ４６が回転自在に取り付けられた回転軸となる軸部材１４９をベース１４２のローラ取付孔１４８に取り付けることによってベース１４２に固定される。このベース１４２に取り付けられたローラ４６は、光ピックアップ８の取付ブロック３２にガイド軸３３，３４と平行となるように設けられたガイド凹部６８内に位置され、ガイド凹部６８の摺動部６５側の面６８ａに点接触する。すなわち、ガイド凹部６８の摺動部６５側の面６８ａに接するようになっているローラ４６は、図１４及び図１５に示すように、振動部材４４の摺動部６５に対向する位置に位置されることで、付勢部材１４５，１４５によって図１４及び図１５中矢印Ｄ_３方向に付勢されている振動部材取付板１４４に取り付けられた振動部材４４の押圧力を常に１点で受けるようになっている。ローラ４６は、摺動部６５より取付ブロック３２に加えられる押圧力を常に複数点ではなく１点で受けるようにすることで、光ピックアップ８を光磁気ディスク３の径方向に送るためのガイド軸３３に、取付ブロック３２のガイド部３８，３９が押圧力を加えないようにし、取付ブロック３２が常に安定してガイド軸３３に沿って移動するようにしている。
【０１０５】
また、ローラ取付板１４３には、付勢部材１４５，１４５の一端が係止される係止部１５０が立設されている。この係止部１５０は、ベース１４２のストッパ１４７に突き当てられる。
【０１０６】
このローラ取付板１４３には、振動部材取付板１４４の図１４及び図１５中矢印Ｄ_３方向及び反矢印Ｄ_３方向に移動をガイドする一対のガイド部１５１，１５１が設けられており、一対のガイド部１５１，１５１には、振動部材取付板１４４の図１４及び図１５中矢印Ｄ_３方向及び反矢印Ｄ_３方向の側縁部が係合される。
【０１０７】
ローラ取付板１４３に直線移動可能に取り付けられる振動部材取付板１４４は、略中央部に、振動部材４４を取り付けるための取付突部５８が設けられており、この取付突部５８には、中央部に取付ねじ５９が螺合されるねじ孔６１が設けられている。また、取付突部５８の周面には、振動部材４４の回転防止部となる複数の位置決め突起６０，６０が設けられている。
【０１０８】
振動部材４４は、上述の駆動装置４１の振動部材４４と同様の構成を有するため省略するが、中央部に、取付孔６６ａが形成されており、この取付孔６６ａの周面には、回動部材４３に設けられた取付突部５８に突設された位置決め突起６０，６０が係合される位置決め凹部６６，６６が形成されている。振動部材４４は、取付孔６６ａに、位置決め凹部６６，６６に取付突部５８の位置決め突起６０，６０を係合させるようにして取り付けられる。この後、取付ねじ５９をねじ孔６５に螺合することによって取り付けられる。振動部材４４は、取付突部５８の位置決め突起６０，６０を取付孔６６ａの位置決め凹部６６，６６に係合されることで、振動部材４４が振動した際にも取付突部５８を中心にして回転してしまうことを防止することができ、摺動部６５を常に光ピックアップ８が取り付けられた取付ブロック３２の接触面３２ａに圧接できるようにしている。
【０１０９】
また、振動部材取付板１４４には、付勢部材１４５，１４５の他端が係止される係止部１５２，１５２が立設されている。付勢部材１４５，１４５は、例えば圧縮コイルバネであり、ローラ取付板１４３の係止部１５０に係止され、他端が振動部材取付板１４４の係止部１５２に係止される。したがって、付勢部材１４５，１４５は、ローラ取付板１４３を係止部１５０がベース１４２のストッパ１４７に常時突き当たるように図１４及び図１５中反矢印Ｄ_３方向に付勢すると共に、振動部材取付板１４４を図１４及び図１５中矢印Ｄ_３方向に付勢する。これにより、振動部材取付板１４４に取り付けられている振動部材４４は、摺動部６５が常時光ピックアップ８が取り付けられた取付ブロック３２の接触面３２ａに押圧され、ローラ取付板１４３に取り付けられたローラ４６は、取付ブロック３２のガイド凹部６８の摺動部６５側の面６８ａに押圧されることになる。すなわち、摺動部６５とローラ４６とは、付勢部材１４５，１４５により互いに向き合う方向に付勢されることになる。
【０１１０】
以上のような駆動装置１４１では、取付ブロック３２の位置に拘わらず、すなわち取付ブロック３２が光磁気ディスクの内周側や外周側に移動して中央位置から変位した位置に移動しても、摺動部６５が光ピックアップ８が取り付けられた取付ブロック３２の接触面３２ａを押圧する押圧方向の延長線上にローラ４６が位置し、この押圧力を受けていることから、光ピックアップ８を光磁気ディスク３の径方向に送るためのガイド軸３３に、取付ブロック３２のガイド部３８，３９が押圧力を加えないようにし、取付ブロック３２が常に安定してガイド軸３３に沿って移動するようにしている。すなわち、この駆動装置１４１では、ガイド軸３３とガイド部３８，３９との摩擦抵抗に関係なく、円滑に取付ブロック３２をガイド軸３３，３４に沿って移動させることができる。
【０１１１】
なお、以上の例では、駆動装置４１，１４１で光ピックアップ８の送り操作と対物レンズ１４のトラッキング制御を行い、光ピックアップ８の対物レンズ駆動機構をフォーカシング制御のみを行う１軸アクチュエータで構成した例を説明したが、本発明はこれに限定されるものではなく、駆動装置４１，１４１で光ピックアップ８の送り操作のみを行い、光ピックアップ８の対物レンズ駆動機構を、フォーカシング制御とトラッキング制御とを行うことができるように従来と同じ２軸アクチュエータで構成するようにしてもよい。
【０１１２】
以上の例では、ディスクカートリッジ２を記録媒体に用いるディスク記録再生装置１を例に取り説明したが、本発明はこれに限定されるものではなく、磁気ディスク、再生専用、追記型若しくは書換型の光ディスク又はこれらのディスクを収納したディスクカートリッジの記録再生装置であってもよい。
【０１１３】
また、本発明は、携帯型の記録再生装置の他、据え置き型の記録及び／又は再生装置に用いてもよい。更に、以上の例では、被駆動体を、記録及び／又は再生部である光ピックアップ８や磁気ヘッド１５が取り付けられる取付ブロック３２とした装置を説明したが、本発明における被駆動体は、記録及び／又は再生部に限定されるものではなく、例えばビデオカメラ、スチルカメラ等に用いるフォーカスレンズの駆動装置等に用いるようにしてもよい。
【０１１４】
【発明の効果】
以上詳細に説明したように、本発明によれば、振動子の各面に少なくとも第１の電極と第２の電極が設けられ、第１の電極と第２の電極に位相の異なる交流電圧を印加し、上記振動子を伸縮させて上記被駆動体に接する摺動部を、振動子の線膨張率と略同じ弾性体をろう付けして形成したので、温度変化によって振動子と弾性体とが収縮したり膨張したときにも、接合部において歪みが発生することを防止し、弾性体と振動子との接合が破壊され、振動子より剥がれることを防止することができる。また、弾性体は、振動子のろう付け部にろう付けされることで、ろう材自身の延性で応力緩和し、接合強度の向上を図ると共に接合部の破壊を防止することができる。更に、弾性体は、振動子にろう付けされることで、振動子との密着性が高められ、振動子に生じた変位が効率良く伝達されるようになり、被駆動体の位置制御を正確に行うことができる。
【０１１５】
また、本発明によれば、被駆動体となる記録及び／又は再生部をこの駆動装置を用いて移動させることで、記録及び／又は再生部の位置制御を正確に行うことができる。
【図面の簡単な説明】
【図１】本発明を適用したディスク記録再生装置を示す斜視図である。
【図２】上記ディスク記録再生装置を示す平面図である。
【図３】上記ディスク記録再生装置の光ピックアップの送り機構に用いる駆動装置の分解斜視図である。
【図４】上記駆動装置の平面図である。
【図５】上記駆動装置の側面図である。
【図６】上記駆動装置に用いる振動部材の断面図である。
【図７】振動部材の摺動部の構成を説明する図である。
【図８】圧電素子の弾性体をろう付けするろう付け部が円弧状に形成されている例を説明する図である。
【図９】摺動部の変形例を説明する図である。
【図１０】上記駆動装置の動作を説明する平面図である。
【図１１】上記駆動装置を駆動する駆動回路のブロック図である。
【図１２】（Ａ）は、振動部材の第１の電極に印加される正弦信号を説明する図であり、（Ｂ）は、振動部材の第２の電極に印加される余弦信号を説明する図であり、（Ｃ）は、振動部材の摺動部の軌跡を位相との関係で説明する図であり、（Ｂ）は、摺動部の楕円軌道を説明する図である。
【図１３】上記ディスク記録再生装置のブロック図である。
【図１４】上記駆動装置の他の例を説明する平面図である。
【図１５】図１１に示す駆動装置の側面図である。
【図１６】従来の駆動装置を説明する図である。
【符号の説明】
１ ディスク記録再生装置、２ ディスクカートリッジ、３ 光磁気ディスク、４ 記録再生用の開口部、６ ディスク駆動用の開口部、７ ディスク回転駆動機構、８ 光ピックアップ、１０ シャーシ、１１ カートリッジホルダ、１４ａ 光ピックアップ用開口部、３１ 送り機構、３２ 取付ブロック、３３，３４ ガイド軸、３８，３９ ガイド部、４１ 駆動装置、４２ ベース、４３ 回動部材、４４ 振動部材、４５ 付勢部材、４６ ローラ、４８ 止めねじ、４９ 支軸、５２ 突出部、５６，５７ 係止部、６２ 圧電素子、６３ 第１の電極、６４ 第２の電極、６５ 摺動部、６５ａ弾性体、６５ｂ ろう付け層、６５ｃ ろう付け部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention uses a vibrator to drive a sliding portion in contact with a driven body in a substantially elliptical motion to move the driven portion along a guide axis by moving the sliding portion close to and away from the driven body. The present invention relates to an apparatus and a recording and / or reproducing apparatus using the driving apparatus as a feed mechanism of a recording and / or reproducing section of a recording medium.
[0002]
[Prior art]
As a driving device, there is a vibration actuator as disclosed in Patent Document 1. As shown in FIG. 16, the vibration actuator 500 drives a vibration member 501 that generates a driving force by ultrasonic vibration, a driven body 502 that relatively moves by the driving force of the vibration member 501, and a vibration member 501 that is driven. A pressing unit 503 for pressing the body 502, a supporting unit 504 for supporting the driven body 502, and the like are provided. The support portion 504 receives the pressing force of the pressing portion 503, and supports the driven body 502 movably.
[0003]
The vibrating member 501 includes a substantially circular piezoelectric element 505 such as PZT (lead zirconate titanate, lead zirconate titanate) and a substantially fan-shaped first electrode 506 for applying an AC voltage having a different phase to the piezoelectric element 505. , A second electrode 507, and a sliding portion 508 for moving the driven body 502. When an AC voltage having a phase difference (π / 2) is applied to the first electrode 506 and the second electrode 507, the vibration member 501 expands and contracts symmetrically and asymmetrically in the radial direction. The vibration member 501 expands and contracts symmetrically and asymmetrically in the radial direction, thereby moving the sliding portion 508 so as to draw a substantially elliptical locus, and moving the sliding portion 508 toward and away from the driven body 502. The driven portion 502 is pressed against the sliding portion 508 by the pressing force of the pressing portion 503, and when the sliding portion 508 is close to the driven portion 502, the driven portion is moved along the support portion 504 by frictional force. .
[0004]
The vibration actuator 500 configured as described above can directly move the driven body 502 as compared with a rotary motor having a rotating shaft that moves the driven body 502 via a gear train, and therefore, the The size and the weight can be reduced. Further, the vibration actuator 500 can hold the position of the driven body 502 without an electric input, and can achieve power saving. Furthermore, since the vibration actuator 500 does not generate a magnetic field and is not affected by the magnetic field, it is possible to easily design components and the like.
[0005]
In this vibration actuator 500, the sliding portion 508 generates a frictional force between the driven body 502 and the propulsion force on the driven body 502, so that the sliding section 508 is securely attached to the piezoelectric element 505. It should not be separated from the piezoelectric element 505 at the time of driving or the like. Patent Literature 2 describes an attachment structure between a piezoelectric element 505 and a sliding portion 508. Specifically, Patent Literature 2 discloses a structure in which a sliding portion 508 is formed by shaving the outer periphery of a piezoelectric element 505, an elastic body having a projection provided by a pair of piezoelectric elements 505 is sandwiched, and a sliding part is formed on the projection of the elastic body. A structure for fitting a moving member (see FIG. 3), a structure for fitting a sliding member to a hole provided on an outer periphery of an elastic body sandwiched between a pair of piezoelectric elements (see FIG. 4), and an outer peripheral portion of a piezoelectric element (See FIG. 5) and a structure in which a substantially U-shaped sliding member is attached to the piezoelectric element (FIGS. 6 and 7). In each of the examples in which the sliding member is attached to the elastic body or the piezoelectric element, the sliding member is integrated with the elastic body or the piezoelectric element using an adhesive.
[0006]
Meanwhile, an optical disk recording / reproducing apparatus on which data is recorded is provided with an optical pickup for recording data on an optical disk rotated by a spindle motor or reading data recorded on the optical disk. This optical pickup is fed in the radial direction of the optical disc in order to access the recording / reproducing position of the optical disc. A feed mechanism for feeding the optical pickup in the radial direction of the optical disk uses a rotary motor having a rotating shaft as a drive source, and feeds the optical pickup in the radial direction of the optical disk via a gear train. Another feed mechanism uses a stepping motor as a drive source, and a feed screw is attached to the stepping motor, and the feed screw is rotated by the stepping motor to feed the optical pickup in the radial direction of the optical disc. .
[0007]
[Patent Document 1]
JP 2001-218482 A
[Patent Document 2]
JP 2001-86772 A
[0008]
[Problems to be solved by the invention]
In the mounting structure of the piezoelectric element 505 and the sliding portion 508 described in Patent Literature 2, the structure in which the outer periphery of the piezoelectric element 505 is shaved to form the sliding portion 508 is formed when the piezoelectric element 505 is cut off. In some cases, micro-cracks or the like may occur, and the vibration characteristics of the piezoelectric element 505 may be significantly deteriorated. In addition, when an adhesive is used when attaching the sliding member to the elastic body or the piezoelectric element, the adhesive is a polymer material, and therefore has a large viscous loss and attenuates the vibration generated by the piezoelectric element 505. In the sliding portion 508, the adhesive may be deformed by the heat generated by the loss, and may not reliably slide on the driven body 502. If the sliding portion 508 and the driven body 502 do not slide reliably, it becomes impossible to accurately control the movement of the driven body 502. Further, the sliding member may be deteriorated due to the aging of the adhesive, and may come off the piezoelectric element 505 or the like.
[0009]
By the way, it can be considered that the vibration actuator 500 is used for a feed mechanism of an optical pickup which is a recording / reproducing unit of a recording / reproducing apparatus for an optical disk or the like described above. In this case, the optical pickup is directly moved in the radial direction of the optical disk by the vibration actuator 500. As described above, when the vibration actuator 500 is used for the feed mechanism of the optical pickup, it is possible to reduce the weight and size of the entire recording / reproducing apparatus, and to further reduce power consumption. The vibration actuator 500 is particularly preferably used for a portable recording / reproducing apparatus that requires miniaturization, weight reduction, and power saving because it can reduce the size, weight, and power consumption of the whole.
[0010]
The feed operation of the optical pickup needs to be performed with high accuracy in accordance with the track pitch of a recording medium such as an optical disk. However, in the above-described vibration actuator 500, when the sliding portion 508 is formed by cutting off the outer periphery of the piezoelectric element 505, the vibration is deteriorated. Further, when the sliding portion 508 of the vibration actuator 500 is formed by using an adhesive, the vibration is attenuated by the adhesive, and the deformation of the adhesive prevents the driven body 502 from sliding reliably. I will. If the vibration actuator 500 in such a state is used for the feed mechanism of the optical pickup, it becomes difficult to accurately control the position of the optical pickup serving as the driven body 502, and therefore, data cannot be accurately recorded. In addition, data cannot be read accurately.
[0011]
The present invention has been made in view of the above problems, and an object of the present invention is to improve transmission characteristics of vibration generated in a vibration member and to improve bonding strength between an elastic body and a vibrator. By providing a drive device capable of achieving a reduction in size, weight, power saving, and the like as a whole, and a recording and / or reproducing device using the drive device as a feed mechanism of a recording and / or reproducing unit of a recording medium. Is to do.
[0012]
[Means for Solving the Problems]
In order to solve the above-described object, a driving device according to the present invention includes a driven body, a guide shaft that movably supports the driven body, and at least a first electrode and a second electrode on each surface of the vibrator. Is provided so that alternating voltages having different phases are applied to the first electrode and the second electrode to expand and contract the vibrator so that the sliding portion in contact with the driven body approaches and separates from the driven body. And a vibrating member for making a substantially elliptical motion. The sliding portion is formed by brazing an elastic body having substantially the same linear expansion coefficient as the vibrator.
[0013]
Further, in order to solve the above-mentioned object, a recording and / or reproducing apparatus according to the present invention provides a recording medium mounting section on which a recording medium is mounted, and an information signal for a recording medium mounted on the recording medium mounting section. A recording and / or reproducing unit for recording and / or reading out an information signal recorded on a recording medium, and a moving unit for moving the recording and / or reproducing unit to a recording and / or reproducing position. The moving unit includes a guide shaft that movably supports the recording and / or reproducing unit, and at least a first electrode and a second electrode on each surface of the vibrator. An AC voltage having a different phase is applied to the electrodes to expand and contract the vibrator, thereby causing the sliding portion in contact with the recording and / or reproducing portion to move substantially in an elliptical manner so as to approach and separate from the recording and / or reproducing portion. The sliding part is formed by brazing an elastic body having substantially the same linear expansion coefficient as the vibrator.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a disc recording / reproducing apparatus to which the present invention is applied will be described with reference to the drawings. This disk recording / reproducing device is, for example, a portable device, and uses a disk cartridge as a recording medium.
[0015]
First, before describing a disk recording / reproducing apparatus to which the present invention is applied, a disk cartridge used in the disk recording / reproducing apparatus will be described. As shown in FIG. 1, a disk cartridge 2 used in a disk recording / reproducing apparatus 1 has a magneto-optical disk 3 rotatable on a cartridge body 2c formed by abutting a pair of an upper half 2a and a lower half 2b. It is stored in.
[0016]
At the center of the magneto-optical disk 3, there is provided a center hole with which a disk table constituting a disk rotation drive mechanism of the disk recording / reproducing apparatus 1 is engaged, and a clamping plate 3a is closed so as to close the center hole. Installed. The clamping plate 3a is formed of a magnetic material such as a metal plate, and is magnetically attracted to a disk table constituting a disk rotation drive mechanism.
[0017]
A part of the signal recording area of the magneto-optical disk 3 is provided in a radial direction on the opposing surfaces of the upper half 2a and the lower half 2b substantially at the center on the front side of the cartridge body 2c for rotatably storing the magneto-optical disk 3. The recording and reproducing openings 4 and 4 are formed so as to be exposed to the outside. The opening 4 on the side of the upper half 2a is for allowing a magnetic head for applying a magnetic field to the magneto-optical recording layer of the magneto-optical disk 3 to enter the inside of the cartridge body 2c, and the opening 4 on the side of the lower half 2b. Is for allowing the optical pickup to face the magneto-optical disk 3.
[0018]
A shutter member 5 for opening and closing the recording and reproducing openings 4 and 4 is slidably mounted on the front side of the cartridge main body 2c. The shutter member 5 is formed by a flat plate member bent in a substantially U-shape along the outer shape of the cartridge main body 2, and each main surface portion is sufficient to close the recording and reproducing openings 4 and 4. It is formed in size. The shutter member 5 opens the recording / reproducing openings 4, 4 only when the shutter member 5 is loaded in the disk recording / reproducing apparatus 1, and closes the openings 4, 4 when not in use.
[0019]
At the center of the lower half 2b, there is provided a substantially circular disk drive opening 6 for exposing the clamping plate 3a of the magneto-optical disk 3 to the outside. When the disk cartridge 2 is loaded into the disk recording / reproducing apparatus 1, the disk table enters through the opening 6, and the clamping plate 3a and the disk table engage.
[0020]
The disk cartridge 2 as described above is loaded into the disk recording / reproducing apparatus 1 with one side surface orthogonal to the front surface of the cartridge body 2c as an insertion end. Then, the shutter member 5 slides along the front surface of the cartridge main body 2c in a direction parallel to the insertion direction of the disk cartridge 2 to open the recording and reproducing openings 4 and 4, thereby recording and reproducing the magneto-optical disk 3. To a possible state.
[0021]
In addition to the magneto-optical disk 3, a read-only optical disk in which data is recorded in advance by a pit pattern is used as a recording medium housed in the cartridge body 2c, and data can be additionally recorded by using an organic dye material in a recording layer. A write-once optical disc, a rewritable optical disc that uses a phase change material for a recording layer, and a rewritable optical disc, a magnetic disc, or the like may be used.
[0022]
A disk recording / reproducing apparatus 1 using the above-described disk cartridge 2 as a recording medium will be described with reference to FIG. 1. This disk recording / reproducing apparatus 1 is an apparatus main body provided with a mounting portion to which the disk cartridge 2 is mounted. And a lid that opens and closes a mounting portion provided in the apparatus main body. As shown in FIGS. 1 and 2, a chassis 10 having a mounting portion 10a on one main surface on which the disk cartridge 2 is mounted is provided in an outer casing constituting the apparatus main body. . A cartridge holder 11 for holding the disk cartridge 2 is rotatably attached to the chassis 10, and the cartridge holder 11 rotates together with a lid constituting a part of the outer casing. In the disc recording / reproducing apparatus 1, the disc cartridge 2 is inserted into the cartridge holder 11 when the cover opens the mounting portion 10a. When the disk cartridge 2 is inserted into the cartridge holder 11, the shutter member 5 slides along the front surface of the cartridge body 2c, and the recording and reproducing openings 4, 4 are opened. The disk cartridge 2 held by the cartridge holder 11 is mounted on the mounting portion 10a by rotating the lid in a direction to close the mounting portion 10a provided on the chassis 10.
[0023]
As shown in FIGS. 1 and 2, the chassis 10 is disposed in a housing constituting the apparatus main body, and has one surface serving as a mounting portion 10a on which the disk cartridge 10 is mounted. A rotating mechanism 7 for rotating the magneto-optical disk 3, and a light beam is applied to the magneto-optical disk 3 rotated by the rotating mechanism 7, and the light is reflected by the reflection film of the magneto-optical disk 3. An optical pickup 8 for detecting a returning light beam is provided.
[0024]
The disk rotation drive mechanism 7 has a spindle motor 12 serving as a drive source for rotating the magneto-optical disk 3. The spindle motor 12 has a drive shaft 12 a on the upper surface side at a substantially central portion on the lower surface side of the chassis 10. It is arranged to protrude. A disk table 13 that is engaged with the clamping plate 3a of the magneto-optical disk 3 is attached to the drive shaft 12a. The disk table 13 has a built-in magnet for magnetically attracting the clamping plate 3a. The disk table 13 enters the cartridge main body 2c through a disk driving opening 4 provided in the lower half 2b, and moves into the clamping plate 3a. Is magnetically attracted. The disk table 13 is mounted with the magneto-optical disk 3 being centered by engaging with the center hole of the magneto-optical disk 3. By mounting the magneto-optical disk 3 on such a disk table 13, the magneto-optical disk 3 is rotated integrally with the disk table 13 in a state where centering is achieved.
[0025]
The optical pickup 8 disposed on the chassis 10 has, as an optical system, a semiconductor laser for emitting a light beam, an objective lens 14 for converging the light beam emitted from the semiconductor laser, and a return beam reflected by the magneto-optical disk 3. A light detector for detecting a light beam is provided. The light beam emitted from the semiconductor laser is focused by the objective lens 14 and applied to the magneto-optical recording layer of the magneto-optical disk 3. The return light beam reflected by the reflection film of the magneto-optical disk 3 is converted into an electric signal by a photodetector and output to an RF amplifier.
[0026]
The optical pickup 8 has an objective lens driving mechanism for driving the objective lens 14 to be displaced in the optical axis direction. The objective lens driving mechanism is a one-axis actuator that displaces the objective lens 14 in a focusing direction that is an optical axis direction of the objective lens 14. The objective lens driving mechanism includes, for example, a magnet disposed on the base of the optical pickup 8 and a coil disposed on the lens holder of the objective lens 14 so as to face the magnet. A driving force is generated by the corresponding current and the magnetic field generated by the magnet, and the objective lens 14 is displaced in the focusing direction.
[0027]
That is, this objective lens drive mechanism does not include a drive unit for tracking control, and is smaller and lighter than an existing objective lens drive mechanism including a two-axis actuator that performs focusing control and tracking control. It is planned. The disk recording / reproducing apparatus 1 controls the optical pickup 8 and the magnetic head 15 in the radial direction of the magneto-optical disk 3 at the time of a track jump or the like by the feed mechanism 31 of the optical pickup 8 which will be described in detail later. And performs tracking control of the objective lens 14. The optical pickup 8 faces the mounting portion 10a side where the disc cartridge 2 is mounted through an optical pickup opening 14a provided with an objective lens 14 corresponding to a moving area of the optical pickup 8 provided in the chassis 10. The chassis 10.
[0028]
A magnetic head 15 is attached to the optical pickup 8 so as to face the objective lens 14 with the magneto-optical disk 3 interposed therebetween. The magnetic head 15 is attached to a distal end of a head support arm 17 attached to a connecting member 16 that connects the optical pickup 8 and the magnetic head 15. The head support arm 17 is formed of an elastically displaceable member such as a gimbal spring, and has a magnetic head 15 so that a magnetic field can be applied to the magneto-optical recording layer of the magneto-optical disk 3 during recording. On the magneto-optical disk 3.
[0029]
The mounting portion 10a provided on one main surface of the chassis 10 additionally includes a positioning projection 18 for positioning the mounting position of the disk cartridge 2 mounted on the chassis 10, and the disk cartridge 2 being mounted on the chassis 10. A detection unit 19 and the like, which are formed by a push-type switch or the like for detecting that the device is mounted, are provided.
[0030]
As shown in FIG. 1, the cartridge holder 11 rotatably mounted on the chassis 10 is formed by bending a thin metal plate, and has a size capable of storing and holding the disk cartridge 2. The cartridge holder 11 has a top plate portion 21 formed in a substantially rectangular shape having a size enough to cover the upper surface side of the disk cartridge 2. First and second cartridge holding portions 22 and 23 are provided to support both sides of the disc cartridge 2 into which the disc cartridge 2 is inserted. The first and second cartridge holding portions 22 and 23 have side walls of the cartridge holder 11 formed by bending both sides of the top plate 21 vertically, and the leading ends of these side walls are parallel to the top plate 21. The cartridge support piece is formed by bending the cartridge support member as described above, and has a substantially U-shaped cross section so that the disk cartridge 2 can be held.
[0031]
The cartridge holder 11 is configured such that an open portion between the first and second cartridge holding portions 22 and 23 on the front surface orthogonal to both sides where the first and second cartridge holding portions 22 and 23 are formed is a cartridge. The disc cartridge 2 is inserted between the first and second cartridge holders 22 and 23 through the cartridge insertion / ejection opening. When the disk cartridge 2 is inserted from the cartridge insertion / removal opening between the first and second cartridge holding portions 22 and 23, the front side on which the shutter member 5 is attached and the rear side opposite to the front side are the first side. And are held by the second cartridge holding portions 22 and 23.
[0032]
At a substantially central portion in the longitudinal direction of the side wall forming the first cartridge holding portion 22 of the cartridge holder 11, the cartridge holder 11 enters a shutter opening member entry groove formed on one side of the disk cartridge 2 inserted into the cartridge holder 11. A shutter release piece 24 for elastically deforming the shutter lock member to release the lock of the shutter member 5 is formed by folding back toward the inside of the cartridge holder 11. The shutter opening piece 24 moves the shutter member 5 in one direction with respect to the cartridge main body 14 inserted into the cartridge holder 11, and moves the shutter member 5 in a direction to open the recording and reproducing openings 4, 4.
[0033]
The shutter member 5 attached to the disk cartridge 2 inserted into the cartridge holder 11 is recorded at a position on the side of the side wall constituting the first cartridge holding portion 22 closer to the cartridge opening than the position where the shutter opening piece 24 is provided. In addition to holding the reproducing openings 4 and 4 in the open positions, the shutter member 5 is held against a cartridge body 14 that is moved in a direction in which the disc cartridge 2 projects from the cartridge holder 11 when the disc cartridge 2 is ejected from the cartridge holder 11. A shutter holding piece 25 for moving the shutter member 5 in a direction to close the recording and reproducing openings 4 and 4 is provided. The shutter holding piece 25 is formed so as to be elastically displaceable integrally with the side wall by forming a U-shaped cut in the side wall. The shutter holding piece 25 is formed so as to extend from the base end portion of the side wall toward the tip end portion, and an engagement projection is formed on the tip end side to engage with the engagement hole of the shutter member 5. The shutter member 5 is held at a position where the recording / reproducing openings 4 and 4 are opened by engaging the collision portion with the engaging hole of the shutter member 5.
[0034]
A magnetic head 15 connected to the optical pickup 8 extends to a top plate 21 of the cartridge holder 11, and the magnetic head 15 is moved from a magnetic head opening 26 provided in the top plate 21 into the cartridge holder 11. It is facing. The magnetic head openings 26 correspond to the recording / reproducing openings 4, 4 opened by the shutter member 5 moving in one direction when the disk cartridge 2 is mounted on the mounting portion 10a of the chassis 10. Position.
[0035]
In order to move the magnetic head 15 close to and away from the magneto-optical disk 3 in accordance with the operation mode, the top plate 21 of the cartridge holder 11 is moved up and down by moving the head support arm 17 with the magnetic head 15 attached to the tip. A member 27 is provided. The lifting operation member 27 has a rotation operation plate 28 which is located on the lower surface side of the head support arm 17 and rotationally operates the head support arm 17, and a pair of rotation operation plates 28 from both sides on the base end side of the rotation operation plate 28. Support arm 29 is formed. The elevating operation member 27 is disposed so as to bridge over the magnetic head opening 26 provided on the top plate 21, and a support shaft protruding from the base end side of the support arm 29 is connected to one of the top plate 21. It is attached to the top plate 21 by pivotally supporting a pivotal support piece formed by cutting and raising the portion. The lifting operation member 27 is rotated by a drive mechanism (not shown) to move the magnetic head 15 up and down in a direction in which the magnetic head 15 approaches and separates from the magneto-optical disk 3 of the disk cartridge 2 mounted on the mounting portion 10 a of the chassis 10. . The lifting operation member 27 lowers the magnetic head 15 so as to slide on the magneto-optical disk 3 when data is recorded on the magneto-optical disk 3, and moves the magnetic head 15 at the time of reproduction, stop, ejection, and the like. It is raised in a direction away from the magneto-optical disk 3.
[0036]
The cartridge holder 11 is configured such that support shafts 30b, 30b on the chassis 10 side are supported by support holes 30a, 30a provided at base ends of the first and second cartridge holding portions 22, 23, respectively. It is rotatably supported by the chassis 10.
[0037]
As shown in FIG. 2, the optical pickup 8 to which the head support arm 17 having the magnetic head 15 attached to the distal end is attached via the connecting member 16 is attached to the mounting portion 10 a of the chassis 10 by the optical pickup feed mechanism 31. The mounted disk cartridge 2 is supported movably in the radial direction of the magneto-optical disk 3. The optical pickup feed mechanism 31 is used to guide the guide shafts 33 and 34 for movably supporting the mounting block 32 on which the optical pickup 8 is mounted in the radial direction of the magneto-optical disk 3, and to attach the guide shafts 33 and 34 to the rear surface of the chassis 10. And the drive unit 41 to which the present invention is applied.
[0038]
The guide shafts 33 and 34 are arranged so as to be parallel to each other in the radial direction of the magneto-optical disk 3, and a pair of shaft mounts whose both ends are provided around the optical pickup opening 14 a of the chassis 10. It is fixed by the parts 35 and 36. At one end of the mounting block 32, there is provided a concave shaft disposing portion 37 on which the guide shaft 33 is disposed, and at both ends of the shaft disposing portion 37, a guide comprising an insertion hole into which the guide shaft 33 is inserted. Parts 38 and 39 are provided. One end of the mounting block 32 is connected to a driving device 41 described later. Further, a shaft insertion hole 40 through which the guide shaft 34 is inserted is provided on the other end side of the mounting block 32, and the guide shaft 34 is inserted into the shaft insertion hole 40. The optical pickup 8 attached to the attachment block 32 is supported by the guide shafts 33 and 34 so as to be movable in the radial direction of the magneto-optical disk 3 of the disk cartridge 2 mounted on the chassis 10. Is moved in the radial direction of the magneto-optical disk 3.
[0039]
As shown in FIGS. 3 to 5, a drive device 41 for moving the mounting block 32 to which the optical pickup 8 is mounted along the guide shafts 33 and 34 in the radial direction of the magneto-optical disk 3 is provided. A base 42 attached to the chassis 10, a pivot member 43 pivotally attached to the base 42, a vibration member 44 attached to the pivot member, and a pivot member 43 to which the vibration member 44 is attached are attached. An urging member 45 for urging in the direction of the block 32 and a roller 46 receiving a pressing force from the vibration member 44 are provided.
[0040]
The base 42 is attached to the back surface of the chassis 10 of the disk recording / reproducing apparatus 1, and the rotating member 43 and the roller 46 are attached to the base 42. The base 42 is mounted by mounting a mounting hole 47, inserting a set screw 48 into the mounting hole 47 and screwing into a screw hole of the chassis 10. The base 42 is provided with a support shaft 49 for rotatably supporting the rotating member 43, and a roller mounting hole 51 for disposing the roller 46 facing the vibration member 44. .
[0041]
The rotating member 43 is rotatably supported on a support shaft 49 erected on the base 42 on the base end side, and the vibration member 44 is mounted on the distal end side. A substantially cylindrical protrusion 52 serving as a rotation support portion is provided on the base member side of the rotation member 43, and a shaft hole 53 through which a support shaft 49 is inserted is formed at the center of the protrusion 52. I have. The rotation member 43 is locked by the locking member 54 when the support shaft 49 is inserted into the shaft hole 53. The support shaft 49 has a locking groove 55 formed at the distal end, and the rotating member 43 locks the locking member 54 in the locking groove 55 after the support shaft 49 is inserted into the shaft hole 53. Thereby, it is rotatably attached to the support shaft 49.
[0042]
A biasing member 45 made of a torsion coil spring or the like is attached to the protrusion 52 of the rotating member 43. The biasing member 45 includes a coil portion 45a and two arms 45b and 45c extending from the coil portion 45a. The biasing member 45 has a coil portion 45 a wound around the projecting portion 52, one arm 45 b is locked by a locking portion 56 of the base 10, and the other arm 45 c is locked by a locking portion 57 of the rotating member 43. The figure shows a direction in which the vibration member 44 is pressed in the direction of the mounting block 32 on which the optical pickup 8 is mounted, with the rotation member 43 being centered on the support shaft 49 erected on the base 42 by being locked. 4 middle arrow D ₁ Bias in the direction.
[0043]
A mounting protrusion 58 for mounting the vibration member 44 is provided on the distal end side of the rotating member 43, and the mounting protrusion 58 has a screw hole 61 into which a mounting screw 59 is screwed at a central portion. Is provided. Further, a plurality of positioning protrusions 60, 60 serving as rotation preventing portions of the vibration member 44 are provided on the peripheral surface of the mounting protrusion 58.
[0044]
As shown in FIG. 6, the vibration member 44 attached to the distal end side of the rotating member 43 has a substantially circular piezoelectric element 62 such as PZT (lead zirconate titanate, lead zirconate titanate). A substantially fan-shaped first electrode 63 and a second electrode 64 are provided on each surface. An AC voltage having a different phase, for example, a phase shifted by 1 / 2π, is applied to the first electrode 63 and the second electrode 64. When an AC voltage having a different phase is applied to the first electrode 63 and the second electrode 64, the piezoelectric element 62 expands and contracts symmetrically and asymmetrically in the radial direction. On the peripheral surface of the vibration member 44, a sliding portion 65 that slides on the flat contact surface 32a on the short side of the mounting block 32 on which the optical pickup 8 is mounted is provided. As shown in FIG. 7, the sliding portion 65 is formed by joining an elastic body 65a in contact with the contact surface 32a of the mounting block 32 to the piezoelectric element 62 by a brazing layer 65b. Here, the elastic body 65a is selected from a material whose linear expansion coefficient is substantially the same as that of the piezoelectric element 62 at room temperature to brazing temperature. Even when the piezoelectric element 62 and the elastic body 65a contract or expand due to a temperature change, it is possible to prevent the occurrence of distortion at the joint portion, and to break the joint between the elastic body 65a and the piezoelectric element 62, thereby causing the elastic body 65a This is for preventing the peeling from the piezoelectric element 62.
[0045]
Specifically, as the elastic body 65a, a material whose linear expansion coefficient is in a range of ± 40% of the linear expansion coefficient of the piezoelectric element 62 is selected. Within this range, the contraction and expansion when the temperature returns to room temperature can be absorbed by elastic deformation, and the joint generated between the piezoelectric element 62 and the elastic body 65a can be destroyed by the distortion generated. This is because it can be prevented.
[0046]
Here, for example, PZT is used for the piezoelectric element 62. The linear expansion coefficient of PZT is generally 5 to 10 × 10 ^-6 / ° C., and a metal such as Group VIa metal, chromium, molybdenum, tungsten, or the like having a linear expansion coefficient within a range of ± 40% can be selected as the elastic body 65a. In addition, when PZT is used for the piezoelectric element 62, as the elastic body 65a, an alloy using a metal belonging to the group VIa, an alloy having a low coefficient of thermal expansion, or a metal such as Kovar (Fe—Co—Ni) can be used. . Therefore, group VIII nickel or the like is not used for the elastic body 65a.
[0047]
[Table 1]

[0048]
The PZT in Table 1 was used in this example, and the coefficient of linear expansion was 6.7 × 10 ^-6 / ° C. As is clear from Table 1, molybdenum has a coefficient of linear expansion of 5.1 × 10 ^-6 / ° C, a PZT ratio of −23.9%, and tungsten has a coefficient of linear expansion of 4.5 × 10 ^-6 / ° C., the PZT ratio to −32.8%, and chromium has a linear expansion coefficient of 6.5 × 10 ^-6 / ° C, the PZT ratio is -2.99%, and Kovar has a coefficient of linear expansion of 5.3 x 10 ^-6 / ° C. and a PZT ratio of −20.9%. When PZT is used for the piezoelectric element 62, these metals are in a range of ± 40% of the linear expansion coefficient of PZT, and are used as the elastic body 65a. Can be used. In contrast, nickel has a coefficient of linear expansion of 13.3 × 10 ^-6 / C, and the PZT ratio is + 98.5%, which is out of the range of ± 40% of the linear expansion coefficient of PZT, and cannot be used as the elastic body 65a.
[0049]
In this example, the piezoelectric element 62 has a linear expansion coefficient of 6.7 × 10 ^-6 / PZT of 5.1 ° C ^-6 / ° C. was used as the elastic body 65a.
[0050]
The brazing layer 65b that joins the elastic body 65a to the piezoelectric element 62 enhances the adhesion between the piezoelectric element 62 and the elastic body 65a, and efficiently transmits the displacement generated in the piezoelectric element 62 to the elastic body 65a. Further, the distortion of the joint when the piezoelectric element 62 and the elastic body 65a expand or contract due to a temperature change is stress-relaxed by the ductility of the brazing material itself, thereby improving the joint strength and preventing the joint from being broken. .
[0051]
When molybdenum is used for the elastic body 65a and PZT is used for the piezoelectric element 62, the brazing material used for the joining is 6% or less for silver brazing of 72% silver and 20% copper (JIS standard: BAg-8). An active silver brazing material to which titanium is added is used. Silver brazing material (JIS: BAg-8) is often used for joining metal and ceramic, but cannot be joined to PZT, and molybdenum also has an oxide film on its surface, making joining difficult. On the other hand, in the activated metal braze to which titanium is added, titanium distributed in the brazing material gathers at the bonding interface, and reacts with oxygen in PZT and an oxide film on the surface of molybdenum to be bonded. The content of titanium is preferably large within the range of 6%. However, if it exceeds 6%, diffusion becomes slow due to increased uneven distribution of titanium, and after brazing, the copper-titanium metal Since the compound particles remain, the brazing strength decreases and the brazing strength varies, it cannot be used. In this example, active silver solder containing 68% of Ag, 26% of Cu, and 6% of Ti was used.
[0052]
Note that a flux may be applied to the brazing portion 65c of the piezoelectric element 62 as a pretreatment in order to increase the bonding strength, or a metal sputtering process of gold, titanium, or the like may be performed. And a metal foil such as gold or copper may be diffusion bonded.
[0053]
As shown in FIG. 7, the portion where the elastic body 65a is joined is a brazing portion 65c facing the contact surface 32a of the mounting block 32 of the piezoelectric element 62. The brazing portion 65c is formed to be substantially parallel to the contact surface 32a of the mounting block 32, and has a D-cut shape. The brazing portion 65c serving as a joining portion of the elastic body 65a is made substantially parallel to the contact surface 32a of the mounting block 32, so that the thickness of the brazing layer 65b can be made uniform. As shown in the figure, it is prevented from being joined to the brazing portion 65c in an inclined state, the joining strength is improved, and the displacement of the piezoelectric element 62 can be efficiently transmitted to the elastic body 65a.
[0054]
As shown in FIG. 7, the elastic body 65a uses a flat member to increase the contact area with the contact surface 32a of the mounting block 32, thereby increasing the frictional force with the contact surface 32a. The mounting block 32 is formed so as to be movable. Of course, as shown in FIG. 9, the elastic body 65a is formed such that the brazing surface side is formed flat, so that it can be securely joined to the brazing portion 65c, and the contact surface 32a side is formed in a substantially arc shape. Is also good.
[0055]
In the sliding portion 65 configured as described above, when the piezoelectric element 62 is displaced symmetrically and asymmetrically in the radial direction, the elastic body 65a joined to the brazing portion 65c selectively contacts the contact surface 32a. . That is, the vibrating member 44 expands and contracts symmetrically and asymmetrically in the radial direction by applying alternating voltages having different phases to the first electrode 63 and the second electrode 64, whereby the sliding portion 65 It moves so as to draw a substantially elliptical locus, and approaches and separates from the contact surface 32a of the mounting block 32. Since the sliding portion 65 is attached to the rotating member 43 urged by the urging member 45 in the direction of the mounting block 32, the sliding portion 65 is pressed by the urging force of the urging member 45. Note that the present invention further applies an AC voltage having a different phase to the first and second electrodes 63 and 64 on one surface side and the first and second electrodes 63 and 64 on the other surface side. It may be.
[0056]
As shown in FIGS. 3 to 5, a mounting hole 66 a is formed in the center of the vibration member 44, and a mounting projection provided on the rotating member 43 is formed on a peripheral surface of the mounting hole 66 a. Positioning recesses 66, 66 are formed in which the positioning projections 60, 60 projecting from 58 are engaged. The vibration member 44 is attached to the attachment hole 66a such that the positioning protrusions 60, 60 of the attachment protrusion 58 are engaged with the positioning recesses 66, 66, and then the attachment screw 59 is screwed into the screw hole 65. Attached by The vibration member 44 engages the positioning protrusions 60 of the mounting protrusion 58 with the positioning recesses 66 of the mounting hole 66a, so that the vibration member 44 is centered on the mounting protrusion 58 even when the vibration member 44 vibrates. Rotation can be prevented, and the sliding portion 65 can always be pressed against the contact surface 32a of the mounting block 32 on which the optical pickup 8 is mounted.
[0057]
The roller 46 attached to the base 42 is attached to a position facing the sliding portion 65 of the vibration member 44. More specifically, the roller 46 is fixed to the base 42 by attaching a shaft member 67 serving as a rotation shaft to which the roller 46 is rotatably attached to the roller attachment hole 51 of the base 42. The roller 46 attached to the base 42 is located in a guide recess 68 provided in the attachment block 32 of the optical pickup 8 so as to be parallel to the guide shafts 33 and 34, and the guide recess 68 is located on the sliding portion 65 side. Point contact with the surface 68a. That is, the roller 46 that is in point contact with the surface 68a of the guide recess 68 on the sliding portion 65 side is provided at a position facing the sliding portion 65 of the vibration member 44 as shown in FIGS. The arrow D in FIG. ₁ The pressing force of the vibrating member 44 attached to the rotating member 43 urged in the direction is always received at one point, not at a plurality of points. The roller 46 is attached to the guide shaft 33 for feeding the optical pickup 8 in the radial direction of the magneto-optical disk 3 by always receiving the pressing force applied to the mounting block 32 from the sliding portion 65 at one point. The guide portions 38 and 39 of the block 32 do not apply a pressing force, and the mounting block 32 always moves along the guide shaft 33 stably.
[0058]
Here, the drive circuit 71 of the vibration member 44 will be described with reference to FIG. 11. The drive circuit 71 includes a drive voltage detection unit 73 that detects an AC drive voltage supplied to the piezoelectric element 62 of the vibration member 44. A drive current detection unit 74 that detects an AC drive current flowing through the piezoelectric element 62 by an AC drive voltage supplied to the piezoelectric element 62 of the vibration member 44, and saturates the voltage detection signal output from the drive voltage detection unit 73. A first amplifier 75 for amplifying the current detection signal output from the drive current detection unit 74 to a saturation level, a second amplifier 76 for amplifying the current detection signal to a saturation level, a voltage detection signal and a power supply voltage amplified to the saturation level. And a first comparator 77 that generates a pulse signal that turns on and off at the zero crossing point of the voltage detection signal, and a current detection signal that has been amplified to the saturation level. The second comparator 78 generates a pulse signal that is turned on and off at a zero crossing point of the current detection signal by comparing the voltage, and a trigger pulse is generated at the rising edge of the pulse signal output from the first comparator 77. A first monomultivibrator 79, a second monomultivibrator 80 that generates a trigger pulse at the timing of a rising edge of a pulse signal output from the second comparator 78, a voltage phase trigger pulse and a current phase trigger An RS flip-flop circuit 81 for generating a pulse signal having a time width corresponding to a phase difference from a pulse, and an analog control for integrating and smoothing the pulse signal output from the RS flip-flop circuit 81 and supplying the integrated signal to a VCO 83 at a subsequent stage An integrating circuit 82 for generating a voltage; A VCO (Voltage Controlled Oscillator) 83 that generates a clock signal whose frequency is changed according to a voltage, and a first waveform generator that generates a sine wave signal having a frequency 1 / n of the frequency of the clock signal output from the VCO 83 84, a second waveform generator 85 that generates a cosine wave signal having the same period and a 90 ° phase shift with respect to the analog signal output from the first waveform generator 84, and a first waveform A first power amplifier 86 that power-amplifies the sine wave signal output from the generator 84 and supplies the sine wave signal to the piezoelectric element 62 of the vibration member 44, and power-amplifies a cosine wave signal output from the second waveform generator 85. Then, the second power amplifier 87 that supplies the piezoelectric element 62 of the vibration member 44 and the detection signal detected by the drive current detection unit 74 are peak-held, and A peak hold circuit 88 for detecting a peak value, a peak value supplied from the peak hold circuit 88, and a reference voltage for speed control are compared, and the first power amplifier 86 and the first power amplifier 86 A gain control circuit 89 that controls the second power amplifier 87 to vary the drive voltage is provided.
[0059]
The drive voltage detection unit 73 detects an AC drive voltage supplied to the piezoelectric element 62 of the vibration member 44, and outputs a voltage detection signal corresponding to the detected drive voltage to the first amplifier 75. The drive current detection unit 74 detects an AC drive current flowing through the piezoelectric element 62 based on an AC drive voltage supplied to the piezoelectric element 62 of the vibration member 44, and generates a second current detection signal corresponding to the detected drive current. Is output to the amplifier 76.
[0060]
The first amplifier 75 amplifies the voltage detection signal output from the drive voltage detection unit 73 to a saturation level, and supplies the same to the first comparator 77. The first comparator 77 compares the voltage detection signal amplified to the saturation level with the power supply voltage, and generates a pulse signal that turns on and off at a zero cross point of the voltage detection signal. The pulse signal output from the first comparator 77 is supplied to a first mono multivibrator 79.
[0061]
The second amplifier 76 amplifies the current detection signal output from the drive current detection unit 74 to a saturation level, and supplies the same to the second comparator 78. The second comparator 78 compares the current detection signal amplified to the saturation level with the power supply voltage, and generates a pulse signal that is turned on and off at a zero cross point of the current detection signal. The pulse signal output from the second comparator 78 is supplied to the second mono multivibrator 80.
[0062]
The first mono multivibrator 79 generates a trigger pulse at the timing of the rising edge of the pulse signal output from the first comparator 77. This trigger pulse is a trigger pulse representing the phase of the drive voltage supplied to the piezoelectric element 62 (hereinafter, referred to as a voltage phase trigger pulse). The voltage phase trigger pulse output from the first mono multivibrator 79 is It is supplied to the RS flip-flop circuit 81. The second mono multivibrator 80 generates a trigger pulse at the timing of the rising edge of the pulse signal output from the second comparator 78. This trigger pulse is a trigger pulse representing the phase of the drive current supplied to the piezoelectric element 62 (hereinafter, referred to as a current phase trigger pulse). The current phase trigger pulse output from the second mono multivibrator 80 is It is supplied to the RS flip-flop circuit 81.
[0063]
The RS flip-flop circuit 81 generates a pulse signal having a time width according to the phase difference between the voltage phase trigger pulse and the current phase trigger pulse. The RS flip-flop circuit 81 outputs to the integration circuit 82 a pulse that is turned on at the timing when the voltage phase trigger pulse is supplied and turned off at the timing when the current phase trigger pulse is supplied. When the timing of the voltage phase trigger pulse coincides with the timing of the current phase trigger pulse, that is, the RS flip-flop circuit 81 determines that the phase difference between the drive voltage supplied to the piezoelectric element 62 and the drive current flowing through the piezoelectric element 62 is zero. Sometimes, a pulse having a predetermined time width is output. The predetermined time width is a time width during which the reference voltage Vref is output when integration is performed by the integration circuit 82 at the subsequent stage.
[0064]
The integration circuit 82 integrates the pulse signal output from the RS flip-flop circuit 81 and generates an analog control voltage to be supplied to the subsequent VCO 83. The VCO 83 generates a clock signal whose frequency is changed according to the input analog control voltage. The center frequency of the VCO 83 generates a clock signal having a frequency n times the resonance frequency f0 of the piezoelectric element 62 of the vibration member 44 (for example, n = 90). The VCO 83 fluctuates from a frequency n times the lower limit frequency f1 to a frequency n times the upper limit frequency f2 around the center frequency n · f0 of the clock signal to be output. The lower limit frequency f1 and the upper limit frequency f2 are frequencies at a point 3 dB lower than the amplitude value obtained at the resonance frequency f0. The VCO 83 supplies a clock signal whose frequency is controlled according to the control voltage to the first waveform generator 84 and the second waveform generator 85.
[0065]
The first waveform generator 84 stores the amplitude data for one wavelength of the sine wave in association with the addresses from 0 to (n-1). Specifically, one wavelength of the sine wave is divided into n and sampled, and the sampled value is stored in association with addresses 0 to (n-1). The first waveform generator 84 periodically counts the values of 0 to (n-1) by the clock supplied from the VCO 83, and reads out the amplitude data of the address of the counted value. Then, the first waveform generator 84 converts the read amplitude data from a digital signal to an analog signal, and outputs the analog signal to the first power amplifier 86. As described above, the analog signal output from the first waveform generator 84 fluctuates from the lower limit frequency f1 to the upper limit frequency f2 around the resonance frequency f0.
[0066]
The second waveform generator 85 converts the amplitude data for one wavelength of the cosine wave whose phase is shifted by 90 ° with respect to the sine wave stored in the first waveform generator 84 from 0 to (n−1). ) Are stored in correspondence with the addresses up to). Specifically, one wavelength of the cosine wave is divided into n and sampled, and the sampled value is stored in correspondence with addresses 0 to (n-1). The second waveform generator 85 periodically counts the values of 0 to (n-1) by the clock supplied from the VCO 83, and reads out the amplitude data of the address of the counted value. Then, the second waveform generator 85 converts the read amplitude data from a digital signal to an analog signal and outputs an analog signal. Thus, the analog signal output from the second waveform generator 85 is the same as the analog signal output from the first waveform generator 84, but is a cosine wave signal having the same period and a 90 ° phase shift. It becomes.
[0067]
The first power amplifier 86 power-amplifies the sine wave signal output from the first waveform generator 84 and supplies the amplified signal to the first electrode 63 provided on the piezoelectric element 62 of the vibration member 44. Then, the drive voltage applied from the first power amplifier 86 to the vibration member 44 is detected by the drive voltage detection unit 73, and the drive current supplied from the first power amplifier 86 to the piezoelectric element 62 is The detection is performed by the detection unit 74. The second power amplifier 87 amplifies the power of the cosine wave signal output from the second waveform generator 85 and supplies the amplified signal to the second electrode 64 provided in the piezoelectric element 62.
[0068]
The peak hold circuit 88 holds the peak of the detection signal detected by the drive current detection unit 74 and detects the peak value. The peak hold circuit 88 supplies the detected peak value to the gain control circuit 89. The gain control circuit 89 compares the peak value supplied from the peak hold circuit 88 with a reference voltage for speed control, and according to the error signal, the first power amplifier 86 and the second power amplifier 86 87 is controlled to vary the drive voltage.
[0069]
The operation of the drive circuit 71 configured as described above will be described. First, the drive voltage detection unit 73 detects the drive voltage applied to the vibration member 44 and outputs a sine wave voltage detection signal. The voltage detection signal is saturated and amplified by the first amplifier 75 and is converted by the first comparator 77 into a pulse signal indicating a zero-cross point. Then, the first monomultivibrator 79 outputs a voltage phase trigger pulse generated at the timing of the rising edge of the zero cross point.
[0070]
Further, the drive current detection unit 74 detects a drive current flowing through the vibration member 44 and outputs a sine wave current detection signal. The current detection signal is saturated and amplified by the second amplifier 76 and the second comparator 78, and is converted into a pulse signal indicating a zero crossing point. Then, the second mono-multi vibrator 80 outputs a current phase trigger pulse generated at the timing of the rising edge of the zero cross point.
[0071]
Both the voltage phase trigger pulse and the current phase trigger pulse are supplied to the flip-flop circuit 81, and the flip-flop circuit 81 calculates the phase difference. The obtained phase difference is smoothed by the integration circuit 82 and supplied to the VCO 83 as an analog control voltage. The integration circuit 82 outputs the reference voltage Vref when the phase difference is 0, and outputs an analog control voltage that increases and decreases around the Vref.
[0072]
The clock signal output from the VCO 83 has a center frequency that is n times the resonance frequency f0 when the input voltage is Vref (the phase difference is 0), and the frequency is n · f1 to n · It is varied in the range of f2. Then, from the first power amplifier 86, the driving voltage whose frequency is varied in the range of f1 to f2 in accordance with the variation of the input voltage and which is locked at a frequency at which the phase difference with the current becomes zero is output from the vibration member 44. Is supplied to the piezoelectric element 62. That is, as shown in FIG. 12A, a sine signal is applied to the first electrode 63 of the vibration member 44 by the drive circuit 71 as described above, and to the second electrode 64, as shown in FIG. ), A cosine signal whose phase is shifted by π / 2 is applied.
[0073]
For example, the horizontal (X) direction of the vibration member 44, that is, the feed direction of the mounting block 32 to which the optical pickup 8 is mounted expands and contracts according to a sine signal applied to the first electrode 63, and the vertical direction of the vibration member 44. The (Y) direction, that is, the direction approaching or separating from the contact surface 32 a of the mounting block 32 expands and contracts according to the cosine signal applied to the second electrode 64. When a positive voltage is applied to each of the electrodes 63 and 64, the side on which the positive electrodes 63 and 64 are provided extends, and when a negative voltage is applied to each of the electrodes 63 and 64. , The side on which the negative electrodes 63 and 64 are provided contracts. Then, as shown in FIG. 12 (C), the sliding portion 65 moves in the moving direction of the mounting block 32 while moving in the direction approaching or separating from the contact surface 32a of the mounting block 32 to which the optical pickup 8 is mounted. I do. That is, as shown in FIG. 12D, the sliding portion 65 provided on the vibration member 44 moves so as to draw a substantially elliptical trajectory, and moves in a direction approaching the contact surface 32a of the mounting block 32. At this time, it moves in the traveling direction of the mounting block 32 and moves in a direction opposite to the traveling direction when moving in a direction away from the contact surface 32a of the mounting block 32.
[0074]
The operation of the driving device 41 as described above will be described with reference to FIG. 10. For example, when the mounting block 32 on which the optical pickup 8 is mounted is moved to the inner circumference side of the magneto-optical disk 3, that is, the arrow in FIG. D ₂ 12A, a sine signal as shown in FIG. 12A is applied to the first electrode 63, and a cosine signal as shown in FIG. 12B is applied to the second electrode 64. Is done. Then, the sliding portion 65 that contacts the contact surface 32a of the mounting block 32 approaches and separates from the contact surface 32a of the mounting block 32, as shown in FIG. Move in such a direction as to draw a substantially elliptical locus. That is, when the sliding portion 65 moves in a direction approaching the contact surface 32a of the mounting block 32, the mounting block 32 moves in the direction indicated by the arrow D in FIG. ₂ When the mounting block 32 is moved in a direction away from the contact surface 32a of the mounting block 32, the mounting block 32 is moved in a direction in which the mounting block 32 returns to the original position in order to be pushed in the advancing direction. As a result, the vibration member 44 moves the sliding portion 65 in one direction so as to draw a substantially elliptical locus, moves close to and away from the contact surface 32a of the mounting block 32, and The mounting block 32 is pushed in the traveling direction of the sliding portion 65, and the mounting block 32 is ₂ Move in the direction.
[0075]
Although not described in detail, the mounting block 32 is connected to the outer peripheral side of the magneto-optical disk 3, that is, the arrow D in FIG. ₂ When moving in the direction, a sine signal opposite to the above example may be applied to the first electrode 63, and a cosine signal opposite to the above example may be applied to the second electrode 64. Thereby, the sliding portion 65 approaches and separates from the contact surface 32a of the mounting block 32, and moves so as to draw a substantially elliptical locus in a direction opposite to the arrow in FIG. Thereby, the vibration member 44 moves the sliding portion 65 in the other direction so as to draw a substantially elliptical trajectory, and moves close to and away from the contact surface 32a of the mounting block 32, and when close to the contact surface 32a, The mounting block 32 is pushed in the moving direction of the sliding portion 65, and the mounting block 32 is moved in the direction indicated by the arrow D in FIG. ₂ Move in the direction.
[0076]
In the drive device 41 as described above, as shown in FIG. 10, regardless of the position of the mounting block 32, that is, the position where the mounting block 32 moves toward the inner or outer circumference of the magneto-optical disk and is displaced from the center position. , The pressing force applied to the mounting block 32 by the vibrating member 44 is always received at one point by the roller 46, so that the guide shaft 33 for feeding the optical pickup 8 in the radial direction of the magneto-optical disk 3 The guide portions 38 and 39 of the mounting block 32 do not apply a pressing force, and the mounting block 32 always moves along the guide shaft 33 stably. That is, in the driving device 41, the mounting block 32 can be smoothly moved along the guide shafts 33 and 34 regardless of the frictional resistance between the guide shaft 33 and the guide portions 38 and 39.
[0077]
Further, since the elastic body 65 a constituting the sliding portion 65 of the piezoelectric element 62 constituting the vibration member 44 is made of a material having substantially the same linear expansion coefficient as the piezoelectric element 62 and brazed to the piezoelectric element 62. Also, even when the piezoelectric element 62 and the elastic body 65a contract or expand due to a temperature change, it is possible to prevent the occurrence of distortion at the joint portion, and to break the joint between the elastic body 65a and the piezoelectric element 62, 62 can be prevented from being peeled off. Further, since the elastic body 65a is brazed to the brazing portion 65c of the piezoelectric element 62, the stress is reduced by the ductility of the brazing material itself, thereby improving the joining strength and preventing the joint from being broken. . Further, the elastic body 65a is brazed to the piezoelectric element 62, whereby the adhesion to the piezoelectric element 62 is enhanced, and the displacement generated in the piezoelectric element 62 is efficiently transmitted. Position control can be performed accurately.
[0078]
Next, the circuit configuration of the disk recording / reproducing apparatus 1 including the above-described driving device 41 will be described with reference to FIG. An RF amplifier 101 for generating signals, a driver 102 for driving the optical pickup 8, the spindle motor 12, etc., a servo circuit 103 for generating servo signals for the spindle motor 12, etc., and a digital signal processor (hereinafter, referred to as "digital signal processing") DSP) 104, a digital / analog converter (hereinafter simply referred to as a D / A converter) 105 for converting a digital signal to an analog signal, and an analog / digital converter (hereinafter referred to as a D / A converter) for converting an analog signal to a digital signal. , A / D converter) 106 and input / output of digital signals , A buffer memory 108 composed of a D-RAM (Dynamic Random Access Memory), a head drive circuit 109 for controlling the drive of the magnetic head 15, an operation unit 110 for the user to operate, And a system controller 112 for controlling the entire system.
[0079]
The RF amplifier 101 generates an RF signal, a focusing error signal, and a tracking error signal based on an output signal from a photodetector included in the optical pickup 8. Further, the RF amplifier 101 extracts a groove information signal that is absolute position information recorded as a wobbling groove on the magneto-optical disk 3. For example, a focusing error signal is generated by an astigmatism method or the like, and a tracking error signal is generated by a three-beam method, a push-pull method, or the like. Then, the RF amplifier 101 outputs the RF signal and the groove information signal to the DSP 104, and outputs the focusing error signal and the tracking error signal to the servo circuit 103.
[0080]
The servo circuit 103 performs focusing servo control based on a focusing error signal supplied from the RF amplifier 101, a tracking error signal, and servo control of the driving device 41 and the spindle motor 12 based on a track jump command and an access command from the system controller 112. And so on.
[0081]
Specifically, the servo circuit 103 detects an error amount from a target value in the focusing direction from the focusing error signal supplied from the RF amplifier 101, and outputs a servo signal based on the detection result to the driver 102. The driver 102 outputs a driving current corresponding to the focusing servo signal to a focusing coil of an objective lens driving mechanism of the optical pickup 8 so that the objective lens 14 is moved toward and away from the signal recording surface of the magneto-optical disk 3. Drive displacement in the direction.
[0082]
The servo circuit 103 controls the driving device 41 based on a tracking error signal, a track jump command and an access command from the system controller 112, and the like. The servo circuit 103 drives the spindle motor 12 via the driver 102 so as to rotate the magneto-optical disk 3 at a constant angular velocity or a constant linear velocity, and outputs a control signal based on a command from the system controller 112 to the driver 102. To control the drive or stop of the spindle motor 12. Further, the servo circuit 103 supplies a control signal based on a command from the system controller 112 to the driver 102, thereby controlling the turning on or off of the semiconductor laser in the optical pickup 8, and controlling the laser output and the like.
[0083]
The DSP 104 has an address decoder 113 to which a groove information signal is supplied from the RF amplifier 101. The address decoder 113 decodes the groove information signal supplied from the RF amplifier 101 and extracts address information. This address information is supplied to the system controller 112 and used for various drive controls. The DSP 104 includes an EFM / CIRC encoder / decoder 114, a vibration-proof memory controller 115, and a compression encoder / decoder 116.
[0084]
The EFM / CIRC encoder / decoder 114 performs demodulation processing such as EFM (Eight to Fourteen Modulation) demodulation on the RF signal input from the RF amplifier 101 when reproducing data recorded on the magneto-optical disk 3. Error correction decoding such as CIRC (Cross Interleaved Reed-Solomon Code) is performed. When recording data on the magneto-optical disk 3, data temporarily recorded in the buffer memory 108 is input in a predetermined data unit under the control of the anti-vibration memory controller 115, and CIRC or the like is applied to the input data. , And a modulation process such as EFM, and outputs the result to the head drive circuit 109.
[0085]
The anti-shake memory controller 115 controls writing of data to the buffer memory 108 such as a D-RAM (Dynamic-Random Access Memory) and reading of data from the buffer memory 108. Specifically, when reproducing the data recorded on the magneto-optical disk 3, the vibration-proof memory controller 115 writes the data output from the EFM / CIRC encoder / decoder 114 into the buffer memory 108, and thereafter, Data is read in data units, and the read data is output to the compression encoder / decoder 116. When recording data on the magneto-optical disk 3, the vibration-proof memory controller 115 writes the data input from the compression encoder / decoder 116 into the buffer memory 108, and then reads and reads the data in predetermined data units. The data is output to the EFM / CIRC encoder / decoder 114.
[0086]
The compression encoder / decoder 116 compresses and expands data such as audio data. Specifically, when reproducing data recorded on the magneto-optical disk 3, the compression encoder / decoder 116 is compressed by a method such as ATRAC (Adaptive Transform Acoustic Coding) read from the buffer memory 108. The data is expanded and output to the D / A converter 105 or the digital interface 107. Also, when recording data on the magneto-optical disk 3, the compression encoder / decoder 116 compresses digital data from the digital interface 107 or the A / D converter 106 and outputs the compressed data to the buffer memory 108. .
[0087]
The head drive circuit 109 causes the magnetic head 15 to generate an external magnetic field according to the recording data on which the EFM / CIRC encoder / decoder 114 has performed the error correction encoding process and the modulation process. At this time, the head lifting mechanism brings the magnetic head 15 into contact with or close to the surface of the magneto-optical disk 3 opposite to the surface facing the optical pickup 8 based on a command from the system controller 112. In the magneto-optical disk 3, data is recorded by irradiating the magneto-optical recording layer with a light beam by the optical pickup 8 and heating it to a Curie temperature or higher and applying a magnetic field by the magnetic head 15.
[0088]
The operation unit 110 includes operation switches, operation buttons, and the like, and includes, for example, operation information related to a recording or reproduction operation such as reproduction, recording, pause, stop, fast forward, fast rewind, search for a cue, and normal reproduction, Operation information relating to play modes such as program reproduction and shuffle reproduction is supplied to the system controller 112. The display unit 111 includes a liquid crystal display panel or the like, and displays an operation mode state of the magneto-optical disk 3 during recording or reproduction, a track number, a recording time or a reproduction time, an editing operation state, and the like. The system controller 112 executes operation control of each unit according to the operation information supplied from the operation unit 110.
[0089]
Next, the operation of the disk recording / reproducing apparatus 1 configured as described above will be described.
[0090]
First, in a state where the lid is rotated in a direction to open the inside with respect to the apparatus main body constituting the disk recording / reproducing apparatus 1 and the mounting portion 10a formed in the apparatus main body is opened, the disk cartridge 2 As shown in FIG. 1, the shutter member 5 is inserted into the apparatus main body with one side surface orthogonal to the front surface provided with the shutter member 5 as an insertion end. Then, the disk cartridge 2 is held by the cartridge holder 11 linked with the lid. At this time, the shutter lock is released by the shutter release piece 24 provided in the cartridge holder, the shutter member 5 is slid along the front surface of the cartridge body 2c, and the openings 4 and 4 provided in the cartridge body 2c are opened. The cartridge is released to expose the signal recording area of the magneto-optical disk 3 to the outside of the cartridge body 2c over the inner and outer circumferences.
[0091]
When the lid with the inside of the apparatus main body opened is rotated in a direction to close the inside of the apparatus main body, the disc cartridge 2 held in the cartridge holder 11 is attached to the mounting portion 10a formed in the chassis 10. Be attached. Then, the disk table 13 constituting the disk rotation drive mechanism 7 enters into the inside from the drive opening 6 provided substantially at the center of the lower half 2b of the cartridge body 2c. Then, the disk table 13 magnetically attracts the clamping plate 3 a provided on the magneto-optical disk 3, engages with the center hole of the magneto-optical disk 3, and centers the magneto-optical disk 3. In a rotatable state.
[0092]
Next, a case where data is recorded on the magneto-optical disk 3 of the disk cartridge 2 mounted on the mounting portion 10a of the chassis 10 will be described. First, when a recording start button constituting the operation unit 110 is pressed by the user, a recording start signal is input to the system controller 112. Then, the system controller 112 drives the spindle motor 12 to rotate the magneto-optical disk 3 at a constant linear velocity or angular velocity. At the same time, the semiconductor laser constituting the optical pickup 8 is driven, and a light beam is emitted at an output level for reading data.
[0093]
Further, a driving device 41 of the optical pickup feeding mechanism 31 is driven by a driving circuit 71. Specifically, the drive circuit 71 applies a sine signal as shown in FIG. 12A to the first electrode 63 provided on the piezoelectric element 62 of the vibrating member 44, and applies the sine signal to the second electrode 64. A cosine signal generated by shifting the phase by π / 2 with respect to a sine signal applied to the first electrode 63 as shown in FIG. Then, the sliding portion 65 of the vibration member 44 moves so as to draw a substantially elliptical trajectory as shown in FIGS. 12C and 12D. Accordingly, when the sliding portion 65 moves in a direction approaching the contact surface 32a of the mounting block 32, the mounting block 32 is moved by the arrow D in FIG. ₂ When the mounting block 32 is moved in a direction away from the contact surface 32a of the mounting block 32, the mounting block 32 is moved in a direction in which the mounting block 32 returns to the original position in order to be pushed in the advancing direction. The vibration member 44 moves the mounting block 32 on which the optical pickup 8 is mounted in the radial direction of the magneto-optical disk 3 by repeating this operation. As a result, the optical pickup 8 is moved to the inner peripheral side of the magneto-optical disk 3, and the objective lens driving mechanism performs focusing servo control based on the focusing servo signal, and starts reading address data to specify a recording position. . That is, the address decoder 113 generates address information from the groove information signal input from the RF amplifier 101, and outputs the generated address information to the system controller 115.
[0094]
When the system controller 115 specifies the recording position of the recording data based on the address information input from the address decoder 113, the magnetic head 15 is moved closer to the magneto-optical disk 3 by rotating the elevating operation member 27. . At the same time, the semiconductor laser of the optical pickup 8 emits a light beam at an output level for data recording. The magneto-optical disk 3 is irradiated with a light beam by the optical pickup 8 and is heated to the Curie temperature or higher, and data recording is started by applying a magnetic field by the magnetic head 15.
[0095]
At this time, the drive circuit 71 of the drive device 41 constituting the optical pickup feed mechanism 31 receives a thread signal corresponding to a control signal such as a track jump from the system controller 112 from the driver 102 and a tracking error signal of the objective lens from the driver 102. A drive signal is input. The drive circuit 71 moves the optical pickup 8 in the radial direction of the magneto-optical disk 3 as described above based on the drive signal generated based on the thread signal and the tracking servo signal, and records the data on the magneto-optical disk 3. It is moved in a direction perpendicular to the track to perform tracking control of the objective lens 14. In other words, the optical pickup feed mechanism 31 uses the drive unit 41 that generates ultrasonic vibrations, so that the tracking control of the fine objective lens 14 and the radial direction of the magneto-optical disk 3 of the optical pickup 8 can be roughly controlled with respect to the tracking control. And the feed operation of.
[0096]
The recording data to be recorded on the magneto-optical disk 3 is converted into a digital signal by the A / D converter 106 when it is an analog signal, and is inputted from the digital input terminal 120 via the digital interface 107 when it is a digital signal. You. Then, the recording data of the digital signal is compressed by ATRAC by the compression encoder / decoder 116 and temporarily written to the buffer memory 108 by the anti-vibration memory controller 115. After being read out and subjected to EFM modulation and encoding processing such as CIRC relating to error correction by the EFM / CIRC encoder / decoder 114, it is supplied to the head drive circuit 109. Then, the head drive circuit 109 causes the magnetic head 15 to generate an external magnetic field modulated according to the recording data. The magnetic head 15 records data by applying an external magnetic field to a position heated by a light beam from the optical pickup 8 to a temperature higher than the Curie temperature.
[0097]
Next, a case where data recorded on the magneto-optical disk 3 of the disk cartridge 2 is reproduced will be described. When the user presses a reproduction start button constituting the operation unit 110, a reproduction start signal is input to the system controller 112, and the system controller 112 outputs this to the servo circuit 103. The operation of the servo circuit 103 at the time of reproduction is substantially the same as that at the time of recording, and thus the details are omitted. However, at the time of reproduction, it is not necessary to apply a magnetic field to the magneto-optical disk 3. 3 are separated from each other. The semiconductor laser of the optical pickup 8 emits a light beam at an output level for reading data.
[0098]
When the optical pickup 8 irradiates the magneto-optical disk 3 with a light beam and detects the reflected return light beam, the reproduced data is subjected to EFM demodulation by an EFM / CIRC encoder / decoder 114 and error correction decoding processing such as CIRC. Is written to the buffer memory 108 by the anti-vibration memory controller 115. The reproduction data once written in the buffer memory 108 is read out for each predetermined data unit, supplied to the compression encoder / decoder 116, decoded by ATRAC, and decompressed. The expanded reproduction data is converted into an analog signal by the D / A converter 105 and then converted into an audible sound from an electroacoustic converter such as a speaker, an earphone, or a headphone connected to the audio output terminal 117 and output. Is done. The digital signal is directly output from the digital output terminal 119 via the digital interface 107.
[0099]
In the disk recording / reproducing apparatus 1 configured as described above, since the drive unit 41 using the vibration member 44 that performs ultrasonic vibration is used for the feed mechanism 31 of the optical pickup 8, the conventional rotary drive by the drive motor is used. The number of components can be greatly reduced as compared with a mechanism that converts the linear drive into linear drive via a gear group and a rack member, and further reduction in size and weight can be achieved. Further, since the driving device 41 does not require electric power to hold the position of the optical pickup 8, power can be saved. Further, since the driving device 41 does not generate a magnetic field without using a magnet or the like, it is possible to eliminate interference with the magnetic head 15. Further, the disc recording / reproducing apparatus 1 can perform the tracking control of the objective lens 14 and the feeding operation of the optical pickup 8 by the driving device 41, and provide the objective lens driving mechanism of the optical pickup 8 with a coil and a magnet for tracking control. This eliminates the necessity, so that the configuration can be simplified and downsized.
[0100]
As shown in FIGS. 7 and 9, a material having substantially the same linear expansion coefficient as that of the piezoelectric element 62 is selected for the elastic body 65 a that constitutes the sliding portion 65 of the piezoelectric element 62 that constitutes the vibration member 44. Since the piezoelectric element 62 and the elastic body 65a contract or expand due to a temperature change, distortion is prevented from being generated at the joint, and the elastic body 65a and the piezoelectric element It is possible to prevent the connection with the piezoelectric element 62 from being broken and peeling off from the piezoelectric element 62. Further, the elastic body 65a is brazed to the brazing portion 65c of the piezoelectric element 62, so that the stress is relaxed by the ductility of the brazing material itself, the joint strength is improved, and the joint is prevented from being broken. it can. Further, the elastic body 65a is brazed to the piezoelectric element 62, whereby the adhesion to the piezoelectric element 62 is enhanced, and the displacement generated in the piezoelectric element 62 is transmitted efficiently. Accordingly, the driving device 41 can accurately perform minute movement control of the attachment block 32 such as tracking control while miniaturizing the entire device, and can reliably perform data recording and reproduction. In addition, since the displacement of the piezoelectric element 62 can be efficiently transmitted to the contact surface 32a of the mounting block 32 via the elastic body 65a, power can be saved.
[0101]
The driving device 41 described above may have the following configuration in addition to the above. That is, in the above-described example, the vibration member 44 is attached to the rotation member 43, and the rotation member 43 is ₁ Although the vibration device 41 for urging in the direction has been described, in the present invention, as shown in FIGS. 14 and 15, the vibration member 44 is linearly pressed against the contact surface 32a of the mounting block 32 on which the optical pickup 8 is mounted. You may make it.
[0102]
The drive device 141 moves the mounting block 32 on which the optical pickup 8 is mounted in the radial direction of the magneto-optical disk 3 along guide shafts 33 and 34, similarly to the drive device 41 described above. The base 142 is attached to the chassis 10 of the reproducing apparatus 1, the roller attachment plate 143 is provided so as to be linearly movable with respect to the base 142, and the roller 46 receiving the pressing force of the vibration member 44 is attached to the base 142, and the roller attachment plate 143. A vibrating member mounting plate 144 disposed linearly movable with respect to the vibrating member 44, and biasing members 145 and 145 disposed between the roller mounting plate 143 and the vibrating member mounting plate 144. .
[0103]
The base 142 is attached to the back surface of the chassis 10 of the disk recording / reproducing apparatus 1. The base 142 has a roller attachment plate 143 on which the rollers 46 are attached and a mounting block 32 on which the optical pickup 8 is attached. The direction of approaching and separating, that is, arrow D in FIGS. ₃ Direction and counter-arrow D ₃ Attached so that it can move in the direction. An arrow D in FIGS. 14 and 15 of the roller mounting plate 143 is provided on the base 142. ₃ Direction and counter-arrow D ₃ A pair of guide portions 146, 146 for guiding the movement in the direction are provided, and the pair of guide portions 146, 146 are provided with an arrow D in FIGS. ₃ Direction and counter-arrow D ₃ Directional side edges are engaged. Further, the base 142 has an arrow D in FIG. ₃ A stopper 147 for regulating the movement in the direction is provided upright.
[0104]
A roller mounting plate 143 that is linearly movable mounted on the base 142 has a roller mounting hole 148 at one end for disposing the roller 46 in opposition to the sliding portion 65 of the vibration member 44. The roller 46 is fixed to the base 142 by attaching a shaft member 149 serving as a rotation shaft to which the roller 46 is rotatably attached to a roller attachment hole 148 of the base 142. The roller 46 attached to the base 142 is located in a guide recess 68 provided in the attachment block 32 of the optical pickup 8 so as to be parallel to the guide shafts 33 and 34, and the guide recess 68 is located on the sliding portion 65 side. Point contact with the surface 68a. That is, the roller 46 that comes into contact with the surface 68a of the guide recess 68 on the sliding portion 65 side is located at a position facing the sliding portion 65 of the vibration member 44, as shown in FIGS. 14 and 15 by the urging members 145 and 145. ₃ The pressing force of the vibration member 44 attached to the vibration member attachment plate 144 urged in the direction is always received at one point. The roller 46 always receives the pressing force applied to the mounting block 32 from the sliding portion 65 at one point instead of a plurality of points, so that the guide shaft for feeding the optical pickup 8 in the radial direction of the magneto-optical disk 3 is provided. The guide portions 38 and 39 of the mounting block 32 do not apply a pressing force to the mounting block 33, and the mounting block 32 always moves along the guide shaft 33 stably.
[0105]
The roller mounting plate 143 is provided with an upright locking portion 150 at which one end of each of the urging members 145 and 145 is locked. The locking portion 150 is abutted against a stopper 147 of the base 142.
[0106]
The roller mounting plate 143 is provided with an arrow D in FIGS. ₃ Direction and counter-arrow D ₃ A pair of guide portions 151 and 151 for guiding the movement in the direction are provided, and the pair of guide portions 151 and 151 are provided with an arrow D in FIGS. 14 and 15 of the vibration member mounting plate 144. ₃ Direction and counter-arrow D ₃ Directional side edges are engaged.
[0107]
The vibrating member mounting plate 144 movably mounted on the roller mounting plate 143 is provided with a mounting protrusion 58 for mounting the vibration member 44 substantially at the center thereof. Is provided with a screw hole 61 into which the mounting screw 59 is screwed. Further, a plurality of positioning protrusions 60, 60 serving as rotation preventing portions of the vibration member 44 are provided on the peripheral surface of the mounting protrusion 58.
[0108]
The vibration member 44 has the same configuration as the vibration member 44 of the driving device 41 described above, but is omitted. However, a mounting hole 66a is formed in the center portion, and a rotation surface is provided on the peripheral surface of the mounting hole 66a. Positioning recesses 66, 66 are formed in which the positioning protrusions 60, 60 protruding from the mounting protrusion 58 provided on the member 43 are engaged. The vibration member 44 is attached to the attachment hole 66a such that the positioning protrusions 60, 60 of the attachment protrusion 58 are engaged with the positioning recesses 66, 66. Thereafter, the mounting is performed by screwing the mounting screw 59 into the screw hole 65. The vibration member 44 engages the positioning protrusions 60 of the mounting protrusion 58 with the positioning recesses 66 of the mounting hole 66a, so that the vibration member 44 is centered on the mounting protrusion 58 even when the vibration member 44 vibrates. Rotation can be prevented, and the sliding portion 65 can always be pressed against the contact surface 32a of the mounting block 32 on which the optical pickup 8 is mounted.
[0109]
The vibrating member mounting plate 144 has upright portions 152 and 152 at which the other ends of the urging members 145 and 145 are locked. The urging members 145 and 145 are, for example, compression coil springs, and are locked by the locking portions 150 of the roller mounting plate 143, and the other ends are locked by the locking portions 152 of the vibration member mounting plate 144. Therefore, the urging members 145 and 145 are arranged so that the locking portion 150 always hits the stopper 147 of the base 142 with the roller mounting plate 143. ₃ 14 and 15, the vibration member mounting plate 144 is moved in the direction indicated by an arrow D in FIGS. ₃ Bias in the direction. As a result, the sliding portion 65 of the vibration member 44 attached to the vibration member attachment plate 144 is constantly pressed against the contact surface 32a of the attachment block 32 to which the optical pickup 8 is attached, and attached to the roller attachment plate 143. The roller 46 is pressed against the surface 68 a of the mounting block 32 on the sliding portion 65 side of the guide concave portion 68. That is, the sliding portion 65 and the roller 46 are urged by the urging members 145 and 145 in directions facing each other.
[0110]
In the driving device 141 as described above, irrespective of the position of the mounting block 32, that is, even if the mounting block 32 moves to the inner peripheral side or the outer peripheral side of the magneto-optical disk and moves to a position displaced from the center position, the sliding is performed. The roller 46 is located on an extension in the pressing direction in which the moving part 65 presses the contact surface 32a of the mounting block 32 on which the optical pickup 8 is mounted, and the roller 46 is received by this pressing force. 3 so that the guide portions 38 and 39 of the mounting block 32 do not apply a pressing force to the guide shaft 33 for feeding in the radial direction, and the mounting block 32 always moves along the guide shaft 33 stably. I have. That is, in the driving device 141, the mounting block 32 can be smoothly moved along the guide shafts 33 and 34 regardless of the frictional resistance between the guide shaft 33 and the guide portions 38 and 39.
[0111]
In the above example, the driving devices 41 and 141 perform the feeding operation of the optical pickup 8 and the tracking control of the objective lens 14, and the objective lens driving mechanism of the optical pickup 8 is configured by a single-axis actuator that performs only focusing control. However, the present invention is not limited to this, and only the feed operation of the optical pickup 8 is performed by the driving devices 41 and 141, and the objective lens driving mechanism of the optical pickup 8 performs focusing control and tracking control. For this purpose, the same two-axis actuator as that of the related art may be used.
[0112]
In the above example, the disk recording / reproducing apparatus 1 using the disk cartridge 2 as a recording medium has been described as an example. However, the present invention is not limited to this, and a magnetic disk, a read-only, write-once or rewritable type A recording / reproducing apparatus for an optical disk or a disk cartridge containing these disks may be used.
[0113]
Further, the present invention may be used for a stationary recording and / or reproducing apparatus other than a portable recording and reproducing apparatus. Further, in the above-described example, the device in which the driven body is the mounting block 32 to which the optical pickup 8 or the magnetic head 15 as a recording and / or reproducing unit is mounted has been described. The present invention is not limited to a playback unit and / or may be used for a focus lens driving device used for a video camera, a still camera, or the like.
[0114]
【The invention's effect】
As described above in detail, according to the present invention, at least the first electrode and the second electrode are provided on each surface of the vibrator, and the alternating voltages having different phases are applied to the first electrode and the second electrode. The sliding portion that is applied to expand and contract the vibrator and contact the driven body is formed by brazing an elastic body having substantially the same linear expansion coefficient as the vibrator. Even when is contracted or expanded, it is possible to prevent the occurrence of distortion at the joint portion, and to prevent the joint between the elastic body and the vibrator from being broken and peeling off from the vibrator. Further, since the elastic body is brazed to the brazing portion of the vibrator, the stress is relaxed by the ductility of the brazing material itself, the joint strength can be improved, and the joint can be prevented from being broken. Furthermore, the elastic body is brazed to the vibrator, so that the adhesion to the vibrator is enhanced, and the displacement generated in the vibrator is efficiently transmitted, so that the position control of the driven body can be accurately performed. Can be done.
[0115]
Further, according to the present invention, by moving the recording and / or reproducing unit to be driven by using the driving device, the position of the recording and / or reproducing unit can be accurately controlled.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a disk recording / reproducing apparatus to which the present invention is applied.
FIG. 2 is a plan view showing the disk recording / reproducing apparatus.
FIG. 3 is an exploded perspective view of a drive device used for a feed mechanism of an optical pickup of the disk recording / reproducing apparatus.
FIG. 4 is a plan view of the driving device.
FIG. 5 is a side view of the driving device.
FIG. 6 is a sectional view of a vibration member used in the driving device.
FIG. 7 is a diagram illustrating a configuration of a sliding portion of a vibration member.
FIG. 8 is a diagram illustrating an example in which a brazing portion for brazing an elastic body of a piezoelectric element is formed in an arc shape.
FIG. 9 is a diagram illustrating a modification of the sliding portion.
FIG. 10 is a plan view illustrating the operation of the driving device.
FIG. 11 is a block diagram of a driving circuit for driving the driving device.
12A is a diagram illustrating a sine signal applied to a first electrode of the vibration member, and FIG. 12B is a diagram illustrating a cosine signal applied to a second electrode of the vibration member. It is a figure which illustrates the locus | trajectory of the sliding part of a vibration member with respect to a phase, and (B) is a figure which illustrates the elliptical trajectory of a sliding part.
FIG. 13 is a block diagram of the disk recording / reproducing apparatus.
FIG. 14 is a plan view illustrating another example of the driving device.
FIG. 15 is a side view of the driving device shown in FIG.
FIG. 16 is a diagram illustrating a conventional driving device.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 disk recording / reproducing device, 2 disk cartridge, 3 magneto-optical disk, 4 recording / reproducing opening, 6 disk driving opening, 7 disk rotation driving mechanism, 8 optical pickup, 10 chassis, 11 cartridge holder, 14a light Pickup opening, 31 feed mechanism, 32 mounting block, 33, 34 guide shaft, 38, 39 guide, 41 drive, 42 base, 43 rotating member, 44 vibrating member, 45 urging member, 46 roller, 48 Set screw, 49 support shaft, 52 projecting part, 56, 57 locking part, 62 piezoelectric element, 63 first electrode, 64 second electrode, 65 sliding part, 65a elastic body, 65b brazing layer, 65c brazing Attachment part

Claims (12)

A driven body,
A guide shaft movably supporting the driven body,
At least a first electrode and a second electrode are provided on each surface of the vibrator, and alternating voltages having different phases are applied to the first electrode and the second electrode to expand and contract the vibrator, thereby driving the driven electrode. A vibrating member that performs a substantially elliptical motion so that the sliding portion in contact with the body is moved toward and away from the driven body,
A drive device wherein the sliding portion is formed by brazing an elastic body having substantially the same linear expansion coefficient as the vibrator. The drive device according to claim 1, wherein a linear expansion coefficient of the elastic body is in a range of ± 40% of a linear expansion coefficient of the vibrator from a room temperature to a brazing temperature. 2. The drive device according to claim 1, wherein when the linear expansion coefficient of the vibrator is 5 to 10 × 10 ⁻⁶ / ° C., the linear expansion coefficient of the elastic body is 5.1 × 10 ⁻⁶ / ° C. 3. The drive device according to claim 1, wherein the vibrator is made of lead titanate zirconate, and the elastic body is made of molybdenum. The drive device according to claim 1, wherein a joining surface of the electromechanical transducer with the elastic body is formed substantially parallel to a contact surface of the driven body with the elastic body. 2. The driving device according to claim 1, wherein the brazing material for brazing the elastic body to the vibrator is an active metal brazing material containing 6% or less of titanium based on a silver brazing material of 72% silver and 28% copper. A recording medium mounting section on which the recording medium is mounted,
A recording and / or reproducing unit that records an information signal on a recording medium mounted on the recording medium mounting unit and / or reads the information signal recorded on the recording medium;
A moving unit for moving the recording and / or reproducing unit to a recording and / or reproducing position;
The moving unit is provided with a guide shaft that movably supports the recording and / or reproducing unit, and at least a first electrode and a second electrode on each surface of the vibrator, and a first electrode and a second electrode. An AC voltage having a different phase is applied to the electrode, and the vibrator is expanded and contracted so that the sliding portion in contact with the recording and / or reproducing portion is substantially elliptical so as to approach or separate from the recording and / or reproducing portion. A recording and / or reproducing apparatus comprising: a vibrating member to be moved; and wherein the sliding portion is formed by brazing an elastic body having substantially the same linear expansion coefficient as the vibrator. 8. The recording and / or reproducing apparatus according to claim 7, wherein a linear expansion coefficient of the elastic body is in a range of ± 40% of a linear expansion coefficient of the vibrator from a room temperature to a brazing temperature. 8. The recording and / or reproducing apparatus according to claim 7, wherein when the linear expansion coefficient of the vibrator is 5 to 10 × 10 ⁻⁶ / ° C., the linear expansion coefficient of the elastic body is 5.1 × 10 ⁻⁶ / ° C. apparatus. The recording and / or reproducing apparatus according to claim 7, wherein the vibrator is made of lead titanate zirconate, and the elastic body is made of molybdenum. 8. The recording and / or reproducing apparatus according to claim 7, wherein a joining surface of the electromechanical transducer with the elastic body is formed substantially parallel to a contact surface of the driven body with the elastic body. 8. The recording and / or recording device according to claim 7, wherein the brazing material for brazing the elastic body to the vibrator is an active metal brazing material containing 6% or less of titanium based on a silver brazing material of 72% silver and 28% copper. Playback device.

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