JPH0756696B2 - Light focusing position controller - Google Patents
Light focusing position controllerInfo
- Publication number
- JPH0756696B2 JPH0756696B2 JP59053842A JP5384284A JPH0756696B2 JP H0756696 B2 JPH0756696 B2 JP H0756696B2 JP 59053842 A JP59053842 A JP 59053842A JP 5384284 A JP5384284 A JP 5384284A JP H0756696 B2 JPH0756696 B2 JP H0756696B2
- Authority
- JP
- Japan
- Prior art keywords
- tracking
- focusing
- control device
- yoke
- optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/1055—Disposition or mounting of transducers relative to record carriers
- G11B11/10576—Disposition or mounting of transducers relative to record carriers with provision for moving the transducers for maintaining alignment or spacing relative to the carrier
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10502—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing characterised by the transducing operation to be executed
- G11B11/10504—Recording
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0925—Electromechanical actuators for lens positioning
- G11B7/093—Electromechanical actuators for lens positioning for focusing and tracking
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0925—Electromechanical actuators for lens positioning
- G11B7/0932—Details of sprung supports
Landscapes
- Optical Recording Or Reproduction (AREA)
Description
【発明の詳細な説明】 〈技術分野〉 本発明は記録媒体にレーザ光等の光ビームを照射するこ
とによって光学的に情報の記録・再生・消去等を行なう
所謂光ディスク装置の光集束位置制御装置に関し、特に
磁性膜を記録媒体としレーザ光等の光ビームを上記記録
媒体に照射することにより情報の記録・再生・消去を行
う光磁気ディスク装置に用いて好適な光集束位置制御装
置に関する。Description: TECHNICAL FIELD The present invention relates to a so-called optical focusing position control device for an optical disc device that optically records, reproduces, or erases information by irradiating a recording medium with a light beam such as a laser beam. More particularly, the present invention relates to an optical focusing position control device suitable for use in a magneto-optical disk device that records / reproduces / erases information by irradiating the recording medium with a light beam such as a laser beam as a recording medium.
〈従来技術〉 従来、光ディスク装置においてディスクを作動させる場
合、その回転時に面振れによりディスク上の情報トラッ
ク部が上下方向（即ち光軸方向）に変位した。また、デ
ィスクの回転軸とディスクを回転させるモータ軸との間
の偏心によってディスク上の情報トラック部が、左右方
向（即ちディスク半径方向）に変位した。この為光ビー
ムの光集束位置を上記ディスク上の情報トラックの変位
に追従させ常に情報トラック上に位置するように調整す
るべく、上記光集束位置を光軸方向に位置制御（フォー
カス制御）すると共に、ディスク半径方向に位置制御
（トラッキング制御）していた。<Prior Art> Conventionally, when a disc is operated in an optical disc apparatus, an information track portion on the disc is displaced in a vertical direction (that is, an optical axis direction) due to surface wobbling during rotation thereof. Further, the eccentricity between the rotary shaft of the disc and the motor shaft for rotating the disc causes the information track portion on the disc to be displaced in the left-right direction (that is, the disc radial direction). Therefore, in order to adjust the light focusing position of the light beam so as to follow the displacement of the information track on the disk so as to always be positioned on the information track, the light focusing position is position-controlled (focus control) in the optical axis direction. , Position control (tracking control) was performed in the disk radial direction.
従来の上述した光集束位置を制御する為の機構としてよ
く知られるものは、回転ミラーを用いてトラッキング制
御を行なうと共に対物レンズを電磁気力により上下移動
させてフォーカス制御を行なう機構であったが、上述し
た回転ミラーを用いたトラッキング制御ではディスクに
入射する光ビームが垂直方向から傾くという問題があっ
た。その為近年では対物レンズ自体を電磁気力を用いて
上下左右の二軸方向に駆動して上述したトラッキング制
御及びフォーカス制御を行なう機構装置が種々と提案さ
れている。A well-known conventional mechanism for controlling the above-mentioned light focusing position is a mechanism for performing tracking control by using a rotating mirror and performing focus control by vertically moving an objective lens by electromagnetic force. The tracking control using the rotating mirror described above has a problem that the light beam incident on the disk is inclined from the vertical direction. Therefore, in recent years, various mechanical devices have been proposed that drive the objective lens itself in the biaxial directions of up, down, left, and right using electromagnetic force to perform the above-described tracking control and focus control.
〈発明が解決しようとする問題点〉 しかしこの機構装置においても色々な問題がある。<Problems to be Solved by the Invention> However, this mechanical device also has various problems.
すなわち、対物レンズを電磁気力により変動させてフォ
ーカス制御とトラッキング制御とを行なう機構装置をそ
のまま光磁気ディスク装置に適用した場合、次の問題点
が発生する。That is, if the mechanism device for performing the focus control and the tracking control by changing the objective lens by the electromagnetic force is directly applied to the magneto-optical disk device, the following problems occur.
即ち、この対物レンズを電磁気力により変動させてフォ
ーカス制御とトラッキング制御とを行なう機構装置は永
久磁石の磁界を利用するものである為にディスクの近傍
にまで漏洩磁界が達する。しかるに上記ディスクは磁性
膜を記録媒体としているので上記漏洩磁界が上記磁性膜
に影響を及ぼす場合は次の不都合な事になるのである。That is, since the mechanical device that performs focus control and tracking control by changing the objective lens by electromagnetic force uses the magnetic field of the permanent magnet, the leakage magnetic field reaches the vicinity of the disk. However, since the above-mentioned disk uses a magnetic film as a recording medium, the following inconvenience will occur when the leakage magnetic field affects the magnetic film.
（Ｉ） 光磁気ディスクにレーザを照射し昇温せしめそ
れと同時に外部磁界を付与して情報を記録する際に光集
束位置制御装置からの漏洩磁界がディスクに作用すれば
記録情報の品質の低下を持たらす。(I) When the magneto-optical disk is irradiated with a laser to raise the temperature and at the same time an external magnetic field is applied to record information, if the leakage magnetic field from the optical focusing position control device acts on the disk, the quality of recorded information is deteriorated. Have.
（II） 光磁気ディスクにレーザを照射し磁気光学効果
を利用して情程を再生する場合には、上記光集束位置制
御装置からの漏洩磁界がディスクに作用すれば記録が消
去されてしまう虞れがある。(II) When the magneto-optical disk is irradiated with a laser to reproduce the information by utilizing the magneto-optical effect, the recording may be erased if the leakage magnetic field from the optical focusing position control device acts on the disk. There is
以上の様な点から光磁気ディスク装置においては光集束
位置制御装置の漏洩磁界がディスクに作用しないように
管理する必要がある。From the above points, in the magneto-optical disk device, it is necessary to manage so that the leakage magnetic field of the optical focusing position control device does not act on the disk.
〈目 的〉 本発明は以上の点に鑑みなされたもので、光集束位置制
御装置の構造に改良を加えることによってその漏洩磁界
のディスクへの作用を減ずることを目的とするものであ
る。<Objective> The present invention has been made in view of the above points, and it is an object of the present invention to reduce the action of the leakage magnetic field on the disk by improving the structure of the optical focusing position control device.
〈実施例〉 以下本発明に係る光集束位置制御装置の実施例を図面を
用いて詳細に説明する。<Example> An example of the optical focusing position control device according to the present invention will be described in detail below with reference to the drawings.
第１図は光磁気ディスク装置の構造を示す構成説明図で
ある。１はレーザ光２を発射するレーザ光源であり、３
はミラー、４はレーザ光２をディスク記録媒体面に集束
せしめる対物レンズである。５は対物レンズ４を上下左
右に駆動して光集束位置をディスク記録媒体の記録トラ
ック上に追従制御させる光集束位置制御装置であり、６
は以上の光学系を収納する光学ヘッドである。７は情報
の記録，消去時にディスク記録媒体面に磁界を付与する
記録，消去用コイルである。８はディスク記録媒体８′
を内蔵する光磁気ディスク、９は該光磁気ディスクを回
転駆動するモーターである。ここで上記光集束位置制御
装置５によるフォーカス制御、即ち入射レーザの光軸方
向のディスク変位に対する入射レーザビームの集束位置
の微調整は、対物レンズ４を光磁気ディスク８の厚み方
向に移動させることで行なわれ、一方上記光集束位置制
御装置５によるトラッキング制御即ちラジアル方向のデ
ィスク変位に対する入射レーザビームの集束位置の微調
整は対物レンズ４を光磁気ディスク８のラジアル方向に
移動させることで行なわれる。FIG. 1 is a structural explanatory view showing the structure of a magneto-optical disk device. Reference numeral 1 is a laser light source that emits laser light 2, and 3
Is a mirror, and 4 is an objective lens for focusing the laser beam 2 on the surface of the disk recording medium. Reference numeral 5 denotes a light focusing position control device for driving the objective lens 4 vertically and horizontally to follow and control the light focusing position on the recording track of the disk recording medium.
Is an optical head that houses the above optical system. Reference numeral 7 is a recording and erasing coil that applies a magnetic field to the surface of the disk recording medium when recording and erasing information. 8 is a disk recording medium 8 '
A magneto-optical disk incorporating therein, 9 is a motor for rotationally driving the magneto-optical disk. Here, the focus control by the optical focusing position control device 5, that is, the fine adjustment of the focusing position of the incident laser beam with respect to the disc displacement of the incident laser in the optical axis direction, is performed by moving the objective lens 4 in the thickness direction of the magneto-optical disc 8. On the other hand, the tracking control by the optical focusing position control device 5, that is, the fine adjustment of the focusing position of the incident laser beam with respect to the disc displacement in the radial direction is performed by moving the objective lens 4 in the radial direction of the magneto-optical disc 8. .
第２図は上記光集束位置制御装置５の構造を詳細に示し
た側面断面図である。FIG. 2 is a side sectional view showing the structure of the light focusing position control device 5 in detail.
まず、トラッキング制御装置について説明する。10は対
物レンズ４を収納支持する対物レンズ鏡筒であり、該レ
ンズ鏡筒10は中間支持体11に対しトラッキング方向可動
平行バネ12によって左右方向に可動に設置される。13は
トラッキング用永久磁石、14はトラッキング用ヨークプ
レート、15はトラッキング用ヨークであり、これらは閉
磁路を形成し、中間支持体11に固定的に取り付けられ
る。上記トラッキング用ヨークプレート14とトラッキン
グ用ヨーク15との間にはトラッキング用磁気空隙16が設
けられる。17はトラッキング駆動コイルであり、該トラ
ッキング駆動コイル17は上記トラッキング用磁気空隙16
を横切るように配置されると共にレンズ鏡筒10に固着さ
れる。上記トラッキング駆動コイル17にトラッキング制
御電流を流せば、該コイル17に磁界が発生し、上記トラ
ッキング用永久磁石13の発生する磁界との相互作用によ
ってトラッキング駆動コイル17,レンズ鏡筒10,対物レン
ズ４及びカウンタバランス18はディスク半径方向に変位
する。尚、上記カウンタバランス18はトラッキング可動
部の重心位置にトラッキング駆動力が作用するようにレ
ンズ鏡筒10の下部に固定される部材である。以上の構成
によってトラッキング制御装置が形成される。First, the tracking control device will be described. Reference numeral 10 denotes an objective lens barrel that houses and supports the objective lens 4, and the lens barrel 10 is movably installed in the left-right direction with respect to the intermediate support 11 by a tracking direction movable parallel spring 12. Reference numeral 13 is a permanent magnet for tracking, 14 is a yoke plate for tracking, and 15 is a yoke for tracking, which form a closed magnetic circuit and are fixedly attached to the intermediate support 11. A tracking magnetic gap 16 is provided between the tracking yoke plate 14 and the tracking yoke 15. Reference numeral 17 denotes a tracking drive coil, and the tracking drive coil 17 has the tracking magnetic gap 16 described above.
It is arranged so as to cross the lens barrel and is fixed to the lens barrel 10. When a tracking control current is applied to the tracking drive coil 17, a magnetic field is generated in the coil 17, and the tracking drive coil 17, the lens barrel 10 and the objective lens 4 interact with the magnetic field generated by the tracking permanent magnet 13. And the counter balance 18 is displaced in the disk radial direction. The counter balance 18 is a member fixed to the lower portion of the lens barrel 10 so that the tracking driving force acts on the center of gravity of the tracking movable portion. The tracking control device is formed by the above configuration.
次にフォーカス制御装置について説明する。19はフォー
カシング用永久磁石、20はフォーカシング用ヨークプレ
ート、21はフォーカシング用ヨークでありこれらは閉磁
路を形成する。又これらは光集束位置制御装置全体の固
定支持体25に固定的に設置される。上記フォーカシング
用ヨークプレート20とフォーカシング用ヨーク21との間
にはフォーカシング用磁気空隙22が設けられる。23はフ
ォーカス駆動コイルであり、該フォーカス駆動コイル23
は上記フォーカシング用磁気空隙22を横切るように配置
されると共に中間支持体11に固着される。この中間支持
体11は固定支持体25に一方を固着された光軸方向可動平
行バネ24によって上下方向に可動に設置されているの
で、上記フォーカス駆動コイル23にフォーカス制御電流
を流せば上記コイル23に磁界が発生し、上記フォーカシ
ング用永久磁石19の発生する磁界との相互作用によって
中間支持体11によって支えられたトラッキング制御装置
をフォーカス方向に変位せしめる。以上の構成によって
フォーカス制御装置が形成される。Next, the focus control device will be described. Reference numeral 19 denotes a focusing permanent magnet, 20 denotes a focusing yoke plate, and 21 denotes a focusing yoke, which form a closed magnetic circuit. Further, these are fixedly installed on the fixed support 25 of the entire light focusing position control device. A focusing magnetic gap 22 is provided between the focusing yoke plate 20 and the focusing yoke 21. Reference numeral 23 denotes a focus drive coil, and the focus drive coil 23
Is arranged so as to cross the focusing magnetic gap 22 and fixed to the intermediate support 11. Since the intermediate support 11 is movably installed in the vertical direction by the optical axis direction movable parallel spring 24, one of which is fixed to the fixed support 25, if the focus control coil 23 is supplied with a focus control current, the coil 23 is moved. A magnetic field is generated in the tracking control device supported by the intermediate support 11 and displaced in the focus direction by the interaction with the magnetic field generated by the focusing permanent magnet 19. The focus control device is formed by the above configuration.
次に対物レンズ鏡筒10のフォーカス制御機構とトラッキ
ング制御機構に基づく運動特性について説明する。Next, the motion characteristics of the objective lens barrel 10 based on the focus control mechanism and the tracking control mechanism will be described.
（Ｉ） トラッキング制御機構に基づく運動特性につい
て。(I) About motion characteristics based on the tracking control mechanism.
第２図に示される如くトラッキング制御の駆動源は中間
支持体11に固着されたトラッキング用の閉磁路と対物レ
ンズ鏡筒10に固着されたトラッキング駆動コイル17との
間の電磁相互作用である。ここで上記中間支持体11と上
記対物レンズ鏡筒10とは左右方向にのみ可動なトラッキ
ング方向可動弾性体即ちトラッキング方向可動平行バネ
12によって連結されている。以上の構造からトラッキン
グ方向の可動部（対物レンズ4,対物レンズ鏡筒10,トラ
ッキング駆動コイル17等からなる。）の重量をMTとし、
トラッキング方向可動平行バネ12の左右方向のバネ定数
をKTとすると、対物レンズ鏡筒10は左右方向の運動に際
して の共振周波数fT持つ。そして上記電磁相互作用に基づく
トラッキング駆動力FTが付与された時、対物レンズ鏡筒
10のトラッキング方向の変位XTの運動位相遅れは、周波
数をｆ（Hz）とすれば、０＜ｆ＜fTで０゜〜90゜であ
り、fT＜ｆで90゜〜180゜であり、fT≪ｆでは180゜に収
束する。従ってトラッキング目標位置をYTとすればこの
トラッキング目標位置YTへの運動を行なう際のトラッキ
ング駆動力FTの信号の位相を位相進み補償回路によって
進めることによってトラッキング目標位置YTに対するト
ラッキング方向可動部の変位XTの運動位相遅れを180゜
より小さくできる。これにより安定なトラッキング制御
が可能である。As shown in FIG. 2, the driving source for tracking control is electromagnetic interaction between the closed magnetic circuit for tracking fixed to the intermediate support 11 and the tracking drive coil 17 fixed to the objective lens barrel 10. Here, the intermediate support 11 and the objective lens barrel 10 are a tracking direction movable elastic body that is movable only in the left-right direction, that is, a tracking direction movable parallel spring.
Connected by twelve. Based on the above structure, the weight of the movable portion in the tracking direction (including the objective lens 4, the objective lens barrel 10, the tracking drive coil 17, etc.) is M T ,
Letting K T be the spring constant of the movable parallel spring 12 in the tracking direction, the objective lens barrel 10 moves in the horizontal direction. It has a resonance frequency f T. Then, when the tracking driving force F T based on the electromagnetic interaction is applied, the objective lens barrel
When the frequency is f (Hz), the motion phase delay of displacement X T in the tracking direction of 10 is 0 ° to 90 ° when 0 <f <f T , and 90 ° to 180 ° when f T <f. Yes, and converges to 180 ° when f T << f. Therefore, if the tracking target position is Y T , the phase of the signal of the tracking driving force F T when moving to the tracking target position Y T is advanced by the phase advance compensating circuit to move in the tracking direction with respect to the tracking target position Y T. The movement phase delay of the displacement X T of the part can be made smaller than 180 °. This enables stable tracking control.
（II） フォーカス制御機構に基づく運動特性につい
て。(II) On the motion characteristics based on the focus control mechanism.
第２図に示される如くフォーカス制御の駆動源は固定支
持体25側に固着されたフォーカシング用の閉磁路と、中
間支持体11側に固着されたフォーカシング駆動コイル23
との間の電磁相互作用である。上記固定支持体25と上記
中間支持体11とは上下方向に可動なフォーカス方向可動
弾性体即ち光軸方向可動平行バネ24によって連結されて
いる。以上の構造からフォーカス方向の可動部であるト
ラッキング制御装置の重量をMFとし、光軸方向可動平行
バネ24の上下方向のバネ定数をKFとすれば、トラッキン
グ制御装置の上下方向の運動に際して対物レンズ鏡筒10
は の共振周波数（以下１次共振周波数という）fFを持つ。
一方中間支持体11と対物レンズ鏡筒10とはトラッキング
方向可動平行バネ12によって連結されているが、フォー
カス制御の駆動がなされた時トラッキング方向可動平行
バネ12は若干上下方向に弾性を有する為該方向に移動す
る。この為トラッキング方向可動平行バネ12の上下方向
のバネ定数をKT′とすれば対物レンズ鏡筒10は上下方向
の運動に際して の共振周波数（以下２次共振周波数という）ｆ′Ｆを持
つ。以上の様に対物レンズ鏡筒10の上下方向の運動に際
しては１次共振周波数と２次共振周波数とが存在する。
但し、トラッキング方向可動平行バネ12の上下方向のバ
ネ定数KT′は極めて大きく、KT′≫KFである。従って２
共振周波数ｆ′Ｆは１次共振周波数fFに比べて充分高く
ｆ′Ｆ＞fFである。ここで上記電磁相互作用に基づくフ
ォーカシング駆動力FFが付与された時、対物レンズ鏡筒
10のフォーカス方向の変位XFの運動位相遅れは周波数を
ｆとすれば、０＜ｆ＞fFで０゜〜90゜であり、fF＜ｆ＜
ｆ′Ｆで90゜〜270゜であり、ｆ′Ｆ＜ｆで270゜〜360
゜である。尚フォカシング駆動力FFが付与された時フォ
ーカシング制御信号の周波数帯域において、フォーカシ
ング目標位置YFに向かう対物レンズ鏡筒10の変位XFの運
動位相遅れを180゜より小さくする必要があるが、前述
の如くフォーカシング駆動力FFの信号の位相を進める為
に位相進み補償回路を用いたとしても位相進み量に限界
がある為上記した180゜より大巾に超えない程度にしか
補償できない。従って更に補償を行なう為には２次共振
周波数ｆ′Ｆをフォーカシング制御信号の周波数帯域よ
り十分高く設定するようにすることが必要になる。光デ
ィスク装置においては、その用途によりフォーカシング
制御信号の周波数帯域が大きく異なるが一般には１〜4K
Hzである。この点から２次共振周波数ｆ′Ｆを略7KHz以
上に設定することが適当であることが判明した。As shown in FIG. 2, the focus control drive source is a closed magnetic circuit for focusing fixed to the fixed support 25 side, and the focusing drive coil 23 fixed to the intermediate support 11 side.
Electromagnetic interaction between and. The fixed support 25 and the intermediate support 11 are connected by a focus direction movable elastic body that is movable in the vertical direction, that is, an optical axis direction movable parallel spring 24. The weight of the tracking control device is a movable part in the focus direction and M F the above described structure, if the vertical spring constant in the optical axis direction movable parallel spring 24 and K F, upon vertical movement of the tracking control device Objective lens barrel 10
Is Has a resonance frequency (hereinafter referred to as the primary resonance frequency) f F.
On the other hand, the intermediate support 11 and the objective lens barrel 10 are connected by a tracking direction movable parallel spring 12, but when the focus control is driven, the tracking direction movable parallel spring 12 has some elasticity in the vertical direction. Move in the direction. Therefore, if the vertical spring constant of the tracking direction movable parallel spring 12 is set to K T ′, the objective lens barrel 10 will move during vertical movement. Of with f 'F resonance frequency (hereinafter referred to as secondary resonance frequency). As described above, when the objective lens barrel 10 moves in the vertical direction, the primary resonance frequency and the secondary resonance frequency exist.
However, the vertical spring constant K T ′ of the tracking direction movable parallel spring 12 is extremely large, and K T ′ >> K F. Therefore 2
The resonance frequency f ′ F is sufficiently higher than the primary resonance frequency f F , and f ′ F > f F. Here, when the focusing driving force F F based on the electromagnetic interaction is applied, the objective lens barrel
The movement phase delay of the displacement X F in the focus direction of 10 is 0 ° to 90 ° at 0 <f> f F, where f is the frequency, and f F <f <
'There is 90 degrees to 270 degrees in F, f' f 270 ° at F <f ~360
It is ゜. In the frequency band of the focusing control signal when the focusing driving force F F is applied, it is necessary to make the movement phase delay of the displacement X F of the objective lens barrel 10 toward the focusing target position Y F smaller than 180 °. As described above, even if the phase advance compensating circuit is used to advance the phase of the signal of the focusing drive force F F , there is a limit to the amount of phase advance, and the compensation can be made only to the extent of not exceeding 180 ° described above. Thus is possible to be set from the high enough frequency band of the focusing control signal secondary resonance frequency f 'F required in order to further carry out the compensation. In the optical disk device, the frequency band of the focusing control signal varies greatly depending on the application, but it is generally 1 to 4K.
Hz. It setting the secondary resonance frequency f 'F from this point above approximately 7KHz is suitable has been found.
この設定条件を満足せしめる為の機構の設計手法を以下
に述べる。A mechanism designing method for satisfying these setting conditions will be described below.
上記２次共振周波数ｆ′Ｆは前述の如くトラッキング方
向可動平行バネ12の上下方向のバネ定数KT′とトラッキ
ング方向可動部重量MTとによって決定され、バネ定数
KT′を大きくすれば大となり、トラッキング方向可動部
重量MTを小さくすれば大となる。しかし上記トラッキン
グ方向可動部重量MTを小さくする手段は対物レンズ４及
びレンズ鏡筒10の重量を小さくすることに限界がある為
多くは期待できない（通常は0.5g〜10gに設計され
る）。従ってトラッキング方向可動平行バネ12の上下方
向のバネ定数KT′を大きくする事を試みた。トラッキン
グ方向可動平行バネ12のフォーカス方向の長さをxT,厚
さをyTとするとKT′/KT＝（xT/yT）２であることが判明
した。よってトラッキング方向可動平行バネ12の上下方
向のバネ定数KT′を大きくするにはトラッキング方向可
動平行バネ12のフォーカス方向の長さxTを長く、且つ厚
さyTを溝くすればよいことが判る。又、 の関係より、２次共振周波数ｆ′Ｆは である。以上の様な関係からトラッキング方向可動平行
バネ12の厚さyTを20〜50μｍとし、該バネ12の長さXTを
yTの100〜500倍程度に設計すれば充分大きな２次共振周
波数ｆ′Ｆを得ることが判明した。The secondary resonance frequency f ′ F is determined by the vertical spring constant K T ′ of the tracking direction movable parallel spring 12 and the tracking direction movable portion weight M T as described above.
It increases with increasing K T ′, and increases with decreasing moving direction movable portion weight M T. However, the means for reducing the weight M T of the movable portion in the tracking direction cannot be expected much because the weight of the objective lens 4 and the lens barrel 10 is limited (usually designed to be 0.5 g to 10 g). Therefore, an attempt was made to increase the vertical spring constant K T ′ of the tracking direction movable parallel spring 12. It was found that K T ′ / K T = (x T / y T ) 2 where x T is the length in the focus direction and y T is the thickness of the tracking direction movable parallel spring 12. Thus the tracking direction movable parallel to increase the spring vertical spring constant K T of 12 'long focus direction length x T in the tracking direction movable parallel springs 12 may be be and Mizoku thickness y T I understand. or, From the relationship of, the secondary resonance frequency f ′ F is Is. Based on the above relationship, the thickness y T of the tracking direction movable parallel spring 12 is set to 20 to 50 μm, and the length X T of the spring 12 is set to
to sufficiently obtain a large secondary resonance frequency f 'F is found by designing the 100-500 times the y T.
以上の様にトラッキング方向可動平行バネ12を設計すれ
ばフォーカシング制御信号の周波数帯域においてフォー
カシング目標位置に対する対物レンズ４の変位XFの運動
位相遅れを180゜より小さくすることが可能である。そ
の際位相進み補償回路による補償も用いる事は重要であ
る。By designing the movable parallel spring 12 in the tracking direction as described above, the movement phase delay of the displacement X F of the objective lens 4 with respect to the focusing target position can be made smaller than 180 ° in the frequency band of the focusing control signal. In that case, it is important to use compensation by the phase lead compensation circuit.
尚実験によれば上記トラッキング方向可動平行バネ12に
厚みが30〜50μｍのベリリウム銅合金を使用したところ
安定したフォーカス制御及びトラッキング制御が可能と
なった。According to an experiment, stable focus control and tracking control were possible when a beryllium copper alloy having a thickness of 30 to 50 μm was used for the movable parallel spring 12 in the tracking direction.
（III） トラッキング制御機構或いはフォーカス制御
機構におけるダンピング特性向上の為の工夫について。(III) About the device for improving the damping characteristic in the tracking control mechanism or the focus control mechanism.
（Ｉ），（II）において述べた様にトラッキング制御機
構及びフォーカス制御機構を作動させた場合において上
記２種の共振周波数fF,fTが存在する為に、フォーカス
制御方向及びトラッキング制御方向のダイピング特性が
小さい場合に、上記共振周波数fF,fTにおける共振倍率
が大きくなり、フォーカス制御時あるいはトラッキング
制御時に妨害振動が形成される。又上記共振周波数以上
の周波数の入力が加わった時可動部の変位応答の位相遅
れが極めて大きくなりその位相遅れが180゜に近づくた
め光集束位置制御が不安定になる。以上の点からダンピ
ング特性を大きくする為の工夫が必要となり、本発明で
は次の様な工夫を施こしている。As described in (I) and (II), when the tracking control mechanism and the focus control mechanism are operated, the two resonance frequencies f F and f T exist, so that the focus control direction and the tracking control direction are different. When the diping characteristic is small, the resonance magnification at the resonance frequencies f F and f T becomes large, and disturbing vibration is formed during focus control or tracking control. Further, when an input of a frequency higher than the resonance frequency is applied, the phase delay of the displacement response of the movable part becomes extremely large and the phase delay approaches 180 °, so that the light focusing position control becomes unstable. From the above points, it is necessary to devise to increase the damping characteristics, and the present invention has devised the following.
（III−ａ） 第１の工夫構造 第１の工夫構造は光軸方向可動平行バネ及び／又はトラ
ッキング方向可動平行バネの表裏面又は片面にラテック
ス状のダンピング材を塗布する構造である。（金属バネ
に板ゴムを貼るもの等の接着剤によるものはバネが硬化
されバネ定数が高くなるので不利である）。(III-a) First devised structure The first devised structure is a structure in which a latex-like damping material is applied to the front and back surfaces or one surface of the optical axis movable parallel spring and / or the tracking direction movable parallel spring. (Adhesives such as sticking a rubber plate to a metal spring are disadvantageous because the spring is hardened and the spring constant increases.)
上記ダンピング材としてはシリコンゴム、ブチルゴム、
シリコンブチルゴム、アクリルエチレンゴム等の粘弾性
体、発泡ポリウレタン等の発泡合成樹脂、シリコングリ
ス等の粘性流体が利用可能である。As the damping material, silicone rubber, butyl rubber,
Viscoelastic materials such as silicone butyl rubber and acrylic ethylene rubber, foam synthetic resins such as foam polyurethane, and viscous fluids such as silicone grease can be used.
（III−ｂ） 第２の工夫構造 第２の工夫構造は第３図に示した如き光軸方向可動平行
バネ24の表面の相対的変位量の大きな部分Ｃのみにダン
ピング材26を貼付した構造である。(III-b) Second devised structure The second devised structure is a structure in which the damping material 26 is attached only to the part C where the relative displacement amount of the surface of the optical axis direction movable parallel spring 24 is large as shown in FIG. Is.
同図に示す如く、光軸方向可動平行バネ24は２つの同心
円の間をつなぐ形状を有し４本の腕が夫々端部で接続さ
れた平面板バネが上下１枚づつ配置されてなる。この方
向可動平行バネ24によって中間支持体11は固定支持体25
に対して相対的に上下方向にのみ移動可能である（第２
図参照）。上記光軸方向可動平行バネ24の表面には最も
相対的変位量の大きな部分Ｃにダンピング材26が貼付さ
れ、フォーカス方向のダンピング特性を大きくしてい
る。上記ダンピング材26としてはシリコンゴム、ブチル
ゴム、シリコンブチルゴム、アクリルエチレンゴム等の
粘弾性体、発泡ウレタン等の発泡合成樹脂が利用可能で
ある。As shown in the drawing, the movable parallel spring 24 in the optical axis direction has a shape connecting two concentric circles, and four flat leaf springs, each having four arms connected at their ends, are arranged one above the other. This direction movable parallel spring 24 causes the intermediate support 11 to move to the fixed support 25.
It is possible to move only in the vertical direction relative to (the second
See figure). On the surface of the movable parallel spring 24 in the optical axis direction, a damping material 26 is attached to a portion C having the largest relative displacement amount to enhance the damping characteristic in the focus direction. As the damping material 26, it is possible to use a viscoelastic body such as silicone rubber, butyl rubber, silicone butyl rubber, or acrylic ethylene rubber, or a foam synthetic resin such as urethane foam.
（III−ｃ） 第３の工夫構造 第３の工夫構造は光軸方向可動平行バネ及び／又はトラ
ッキング方向可動平行バネをマンガン銅合金、アルミ鉄
合金、ニッケルチタン合金、マグネシウム合金等の防振
合金にて形成する構造である。(III-c) Third devised structure The third devised structure is a vibration-proof alloy such as a manganese-copper alloy, an aluminum-iron alloy, a nickel-titanium alloy, a magnesium alloy, etc., which is a movable parallel spring in the optical axis direction and / or a movable parallel spring in the tracking direction It is a structure formed by.
ここで、以上のIII−a,b,cの工夫構造を互いに組み合わ
せることもダンピング特性を更に向上させる為に有益で
ある。Here, combining the above-mentioned devised structures of III-a, b, and c with each other is also useful for further improving the damping characteristics.
（IV） 本発明に係る光集束位置制御装置を光磁気ディ
スク装置において用いる場合の工夫について。(IV) A device for using the optical focusing position control device according to the present invention in a magneto-optical disk device.
光集束位置制御装置からの漏洩磁界が光磁気ディスク８
の記録媒体８′に作用しないように次の如き工夫が施さ
れる。The leakage magnetic field from the optical focusing position control device causes the magneto-optical disk 8
The following measures are taken so as not to affect the recording medium 8 '.
（IV−ａ） フォーカス制御装置における工夫点。(IV-a) Points to be devised in the focus control device.
第４図（ａ）に本発明に係る工夫を施したフォーカス制
御装置の一部側面断面の模式図を示し、同図（ｂ）に工
夫を施さないフォーカス制御装置の一部側面断面の模式
図を示す。記号N,Sは夫々Ｎ極,S極を示す。同図（ａ）
に示す様に本発明に係る工夫を施したフォーカス制御装
置ではフォーカシング用磁気空隙22が光磁気ディスクに
近い側に形成されている。この構造によれば光磁気ディ
スクの記録媒体８′に作用する漏洩磁界を小さくでき
る。一方同図（ｂ）の如くフォーカシング用磁気空隙2
2′を光磁気ディスクに遠い側に形成した構造のもので
は光磁気ディスクの記録媒体８′面に作用する漏洩磁界
が大きい。同図（ａ），（ｂ）の矢印はその始点の位置
の漏洩磁界の強さを矢印の長さで、漏洩磁界の方向を矢
印の方向で示している。FIG. 4 (a) shows a schematic diagram of a partial side cross section of a focus control device according to the present invention, and FIG. 4 (b) shows a schematic diagram of a partial side cross section of a focus control device without modification. Indicates. The symbols N and S represent N pole and S pole, respectively. The same figure (a)
As shown in FIG. 7, in the focus control device in which the device according to the present invention is devised, the focusing magnetic gap 22 is formed on the side closer to the magneto-optical disk. According to this structure, the leakage magnetic field acting on the recording medium 8'of the magneto-optical disk can be reduced. On the other hand, as shown in Fig. 2 (b), the magnetic gap for focusing 2
In the structure in which 2'is formed on the far side of the magneto-optical disk, the leakage magnetic field acting on the surface of the recording medium 8'of the magneto-optical disk is large. The arrows in (a) and (b) of the same figure show the strength of the leakage magnetic field at the position of the starting point by the length of the arrow and the direction of the leakage magnetic field by the direction of the arrow.
（IV−ｂ） トラッキング制御装置における工夫点。(IV-b) Points to be devised in the tracking control device.
第５図（ａ）に本発明に係る工夫を施したトラッキング
制御装置の一部側面断面の模式図を示し、同図（ｂ）及
び同図（ｃ）に工夫を施さないトラッキング制御装置の
一部側面断面の模式図を示す。同図（ａ）に示す様に本
発明に係る工夫を施したトラッキング制御装置ではトラ
ッキング用永久磁石13が閉磁路の中央に配置されてい
る。この構造によれば光磁気ディスクの記録媒体８′に
作用する漏洩磁界を小さくできる。FIG. 5 (a) shows a schematic diagram of a partial side cross section of a tracking control device according to the present invention, and FIG. 5 (b) and FIG. The schematic diagram of a part side surface cross section is shown. As shown in FIG. 7A, in the tracking control device which is devised according to the present invention, the tracking permanent magnet 13 is arranged at the center of the closed magnetic circuit. According to this structure, the leakage magnetic field acting on the recording medium 8'of the magneto-optical disk can be reduced.
一方同図（ｂ）の如くトラッキング用永久磁石13′を閉
磁路の周囲に配置した構造のもの、或いは同図（ｃ）の
如く磁気回路のディスクに面する方向が開磁路になって
いる構造のものではトラッキング用磁気空隙16′,16″
において働く磁界の大きさが同図（ａ）のトラッキング
用磁気空隙16と同等になるように設計した時光磁気ディ
スクの記録媒体８′面に作用する漏洩磁界は非常に大き
い。On the other hand, as shown in FIG. 2B, the permanent magnet 13 'for tracking is arranged around the closed magnetic path, or as shown in FIG. 1C, the magnetic circuit faces the disk. Magnetic air gap for tracking 16 ', 16 ″
The leakage magnetic field acting on the surface of the recording medium 8'of the magneto-optical disk is very large when designed so that the magnitude of the magnetic field acting at is equal to the magnetic gap 16 for tracking shown in FIG.
（IV−ｃ） トラッキング制御装置の固着位置における
工夫点。(IV-c) Points to be considered in the fixing position of the tracking control device.
トラッキング制御装置において、トラッキング用磁気空
隙内に働く磁界を大きさを一定に設計する場合、トラッ
キング用磁気空隙の間隔が大きい程漏洩磁界が大きくな
るので、上記トラッキング用磁気空隙の間隔は出来るだ
け狭い方がよい。しかし対物レンズは上下左右の二軸方
向に移動させなければならないことから、例えばトラッ
キング制御用磁気回路及びフォーカス制御用磁気回路の
両方を固定支持体に固着した場合にはトラッキングコイ
ルを上記トラッキング用磁気空隙内において二軸方向に
動かさねばならない為に上記磁気空隙の間隔は広くせざ
るを得ない。しかるに上記磁気空隙の間隔を広くするこ
とは上述した理由で不利である。In the tracking control device, when the magnetic field working in the tracking magnetic gap is designed to have a constant magnitude, the larger the gap between the tracking magnetic gaps is, the larger the leakage magnetic field is. Therefore, the gap between the tracking magnetic gaps is as narrow as possible. Better. However, since the objective lens must be moved in the up, down, left and right biaxial directions, for example, when both the tracking control magnetic circuit and the focus control magnetic circuit are fixed to a fixed support, the tracking coil is moved to the tracking magnetic circuit. Since the magnetic gap must be moved biaxially, the magnetic gap must be widened. However, widening the gap of the magnetic gap is disadvantageous for the above-mentioned reason.
この点から、本発明に係る第２図の光集束位置制御装置
ではトラッキング制御用磁気回路が中間支持体11に固着
されている。この構造によればトラッキング駆動コイル
17は上記トラッキング用磁気空隙16内を左右方向にのみ
移動するものであるから、上記磁気空隙16を必要最小限
に狭くでき、従って漏洩磁界を小さくできるものであ
る。From this point, in the optical focusing position control device of FIG. 2 according to the present invention, the tracking control magnetic circuit is fixed to the intermediate support 11. According to this structure, the tracking drive coil
Since the reference numeral 17 moves in the tracking magnetic air gap 16 only in the left-right direction, the magnetic air gap 16 can be made as narrow as possible to a minimum, and therefore the leakage magnetic field can be made small.
〈効 果〉 以上詳細に説明した本発明によれば、光ディスク装置に
て用いられる光ビームを正しく記録媒体に追随させる光
集束位置制御装置において、光磁気ディスクに対する漏
洩磁界の作用を減少せしめ、光磁気記録情報の品質及び
信頼性の向上を促進し得るものである。<Effect> According to the present invention described in detail above, in the optical focusing position control device for correctly following the recording medium with the light beam used in the optical disk device, the action of the leakage magnetic field on the magneto-optical disk is reduced, and It is possible to promote improvement in quality and reliability of magnetic recording information.
第１図は光磁気ディスク装置の構造を示す構成説明図、
第２図は本発明に係る光集束位置制御装置の構造を示す
側面断面図、第３図は光軸方向可動平行バネの平面図、
第４図はフォーカス制御装置の一部側面断面の模式図、
第５図はトラッキング制御装置の一部側面断面の模式図
である。 図中、1:レーザ光源、2:レーザ光、3:ミラー、4:対物レ
ンズ、5:光集束位置制御装置、6:光学ヘッド、7:記録，
消去用コイル、8:光磁気ディスク、9:モーター、10:対
物レンズ鏡筒、11:中間支持体、12:トラッキング方向可
動平行バネ、13:トラッキング用永久磁石、14:トラッキ
ング用ヨークプレート、15:トラッキング用ヨーク、16:
トラッキング用磁気空隙、17:トラッキング駆動コイ
ル、18:カウンタバランス、19:フォーカシング用永久磁
石、20:フォーカシング用ヨークプレート、21:フォーカ
シング用ヨーク、22:フォーカシング用磁気空隙、23:フ
ォーカス駆動コイル、24:光軸方向可動平行バネ、25:固
定支持体、26:ダンピング材。FIG. 1 is a structural explanatory view showing the structure of a magneto-optical disk device,
FIG. 2 is a side sectional view showing the structure of a light focusing position control device according to the present invention, and FIG. 3 is a plan view of a movable parallel spring in the optical axis direction.
FIG. 4 is a schematic diagram of a partial side cross section of the focus control device,
FIG. 5 is a schematic diagram of a partial side cross section of the tracking control device. In the figure, 1: laser light source, 2: laser light, 3: mirror, 4: objective lens, 5: light focusing position control device, 6: optical head, 7: recording,
Erasing coil, 8: Magneto-optical disc, 9: Motor, 10: Objective lens barrel, 11: Intermediate support, 12: Tracking direction movable parallel spring, 13: Tracking permanent magnet, 14: Tracking yoke plate, 15 : Tracking yoke, 16:
Magnetic air gap for tracking, 17: Tracking drive coil, 18: Counter balance, 19: Permanent magnet for focusing, 20: Yoke plate for focusing, 21: Yoke for focusing, 22: Magnetic air gap for focusing, 23: Focus drive coil, 24 : Optical axis movable parallel spring, 25: Fixed support, 26: Damping material.
フロントページの続き (72)発明者 出口 敏久 大阪府大阪市阿倍野区長池町22番22号 シ ヤープ株式会社内 (72)発明者 山岡 秀嘉 大阪府大阪市阿倍野区長池町22番22号 シ ヤープ株式会社内 (56)参考文献 特開 昭58−175144（ＪＰ，Ａ) 特開 昭57−103131（ＪＰ，Ａ) 実開 昭56−77028（ＪＰ，Ｕ) 実開 昭58−155638（ＪＰ，Ｕ) 特公 平５−12779（ＪＰ，Ｂ２) 特公 平５−16091（ＪＰ，Ｂ２)Front page continuation (72) Inventor Toshihisa Exit 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Prefecture Sharp Corporation (72) Hideyoshi Yamaoka 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Prefecture (56) References JP-A-58-175144 (JP, A) JP-A-57-103131 (JP, A) Actual opening Sho-56-77028 (JP, U) Actual opening Sho-58-155638 (JP, U) Japanese Patent Publication 5-12779 (JP, B2) Japanese Patent Publication 5-16091 (JP, B2)
Claims (1)
動するトラッキング制御装置と該トラッキング制御装置
を入射光光軸方向に駆動するフォーカス制御装置とを備
えた光集束位置制御装置において、前記フォーカス制御
装置が、閉磁路を形成するフォーカシング用永久磁石
と、フォーカシング用ヨークプレートと、フォーカシン
グ用ヨークとを有すると共に、前記フォーカシング用ヨ
ークプレートと前記フォーカシング用ヨークとの間に形
成されるフォーカシング用磁気空隙を横切るように配置
されるフォーカス駆動コイルを有し、前記フォーカシン
グ用磁気空隙が前記閉磁路の磁性膜からなる記録媒体に
近い側に形成されると共に、 前記トラッキング制御装置が、閉磁路を形成するトラッ
キング用永久磁石と、トラッキング用ヨークプレート
と、トラッキング用ヨークとを有すると共に、前記トラ
ッキング用ヨークプレートと前記トラッキング用ヨーク
との間に形成されるトラッキング用磁気空隙を横切るよ
うに配置されるトラッキング駆動コイルを有し、前記ト
ラッキング用ヨークと前記トラッキング用ヨークプレー
トとが前記トラッキング用永久磁石を中心とした対称形
状となるように前記閉磁路の中央に前記トラッキング用
永久磁石が配置されてなることを特徴とする光集束位置
制御装置。1. An optical focusing position control device comprising a tracking control device for driving an objective lens barrel in a radial direction of a disk and a focus control device for driving the tracking control device in an incident light optical axis direction. The control device includes a focusing permanent magnet forming a closed magnetic circuit, a focusing yoke plate, and a focusing yoke, and a focusing magnetic gap formed between the focusing yoke plate and the focusing yoke. A focusing drive coil disposed so as to traverse the magnetic field, the focusing magnetic air gap is formed on a side of the closed magnetic path close to a recording medium made of a magnetic film, and the tracking control device forms a closed magnetic path. Tracking permanent magnet and tracking yoke A tracking yoke and a tracking yoke, and a tracking drive coil that is arranged so as to cross a tracking magnetic gap formed between the tracking yoke plate and the tracking yoke. The optical focusing position control device, wherein the tracking permanent magnet is arranged in the center of the closed magnetic path so that the tracking yoke plate and the tracking yoke plate are symmetrical with respect to the tracking permanent magnet.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59053842A JPH0756696B2 (en) | 1984-03-19 | 1984-03-19 | Light focusing position controller |
| US06/600,374 US4658390A (en) | 1983-04-18 | 1984-04-16 | Optical focus position control in an optical memory system |
| DE8484302661T DE3482725D1 (en) | 1983-04-18 | 1984-04-18 | SETTING THE OPTICAL FOCUSING IN AN OPTICAL STORAGE PROCESS. |
| EP84302661A EP0122816B1 (en) | 1983-04-18 | 1984-04-18 | Optical focus position control in an optical memory system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59053842A JPH0756696B2 (en) | 1984-03-19 | 1984-03-19 | Light focusing position controller |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60197947A JPS60197947A (en) | 1985-10-07 |
| JPH0756696B2 true JPH0756696B2 (en) | 1995-06-14 |
Family
ID=12954028
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59053842A Expired - Lifetime JPH0756696B2 (en) | 1983-04-18 | 1984-03-19 | Light focusing position controller |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0756696B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61287045A (en) * | 1985-06-13 | 1986-12-17 | Canon Inc | Optical system driver |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54101415U (en) * | 1977-12-28 | 1979-07-17 | ||
| JPS58155638U (en) * | 1982-04-14 | 1983-10-18 | 株式会社日立製作所 | Objective lens drive device |
-
1984
- 1984-03-19 JP JP59053842A patent/JPH0756696B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60197947A (en) | 1985-10-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4660190A (en) | Optical focus position control in optical disc apparatus | |
| US4658390A (en) | Optical focus position control in an optical memory system | |
| US5182738A (en) | Objective lens actuator using a balance weight therein | |
| EP0115666B1 (en) | Optical focus position control in optical disc apparatus | |
| JP2611966B2 (en) | Objective lens drive | |
| JPH0756696B2 (en) | Light focusing position controller | |
| JPS58182140A (en) | Objective lens driving device | |
| CA1219073A (en) | Optical focus position control in an optical memory system | |
| EP0318772B1 (en) | Optical focus position control device | |
| EP0314200B1 (en) | Optical focus position control device | |
| JP2706357B2 (en) | Optical information recording / reproducing device | |
| Takeshita et al. | Dynamic characteristics of lens actuator for digital video disk | |
| JP2542635B2 (en) | Optical head | |
| JPS59195336A (en) | Controller for light condensing position | |
| JPS6243256B2 (en) | ||
| JP3114348B2 (en) | Precision angular displacement mechanism | |
| JP2621200B2 (en) | Objective lens actuator | |
| JPS6284437A (en) | Drive device for objective lens | |
| JPH02292781A (en) | Voice coil type optical head moving device | |
| JPH0512779B2 (en) | ||
| JPS6212931A (en) | Driving device for objective lens | |
| JPS60246032A (en) | Objective lens driver | |
| JPS59193551A (en) | Controller for light focusing position | |
| JP2791316B2 (en) | Objective lens drive | |
| JP2793582B2 (en) | Objective lens drive |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |