JPS6187226A - Objective actuator for optical head - Google Patents

Objective actuator for optical head

Info

Publication number
JPS6187226A
JPS6187226A JP20891384A JP20891384A JPS6187226A JP S6187226 A JPS6187226 A JP S6187226A JP 20891384 A JP20891384 A JP 20891384A JP 20891384 A JP20891384 A JP 20891384A JP S6187226 A JPS6187226 A JP S6187226A
Authority
JP
Japan
Prior art keywords
objective lens
movable part
coil
tracking
objective
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.)
Pending
Application number
JP20891384A
Other languages
Japanese (ja)
Inventor
Hiroo Nomura
野村　浩朗
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seiko Epson Corp
Original Assignee
Seiko Epson Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Seiko Epson Corp filed Critical Seiko Epson Corp
Priority to JP20891384A priority Critical patent/JPS6187226A/en
Publication of JPS6187226A publication Critical patent/JPS6187226A/en
Pending legal-status Critical Current

Links

Classifications

    • 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

Landscapes

  • Optical Recording Or Reproduction (AREA)

Abstract

PURPOSE:To control a laser focusing point accurately without moving the optical axis of reflected light by moving an objective and a total reflecting mirror in a tracking direction as one body. CONSTITUTION:A tracking coil 13 and a focusing coil 12 are inserted into the gap 21 of the magnetic circuit composed of a permanent magnet 19 and a yoke 20 arranged in parallel to two sides of the focusing coil. When a current iF is flowed to the focusing coil 12 and a current iT is flowed to the tracking coil 13 respectively, the focusing coil 12 receives a vertical force and the track ing coil 13 receives a horizontal force respectively, so that the coils move. The movement of the objective rsults from the composite motion of the both and a two-axial actuator is obtained. The direction of the motion is controlled by a cylindrical guide 16, shaft 17, and bearing 18 provided to the 2nd movable part and the inclination of the optical axis of the objective 10 is prevented. The total reflecting mirror 22 is fixed to a mirror holder 23, which is fixed to the 2nd movable part 15. Therefore, the total reflecting mirror 22 moves horizontally associatively with the tracking-directional motion of the objective 10.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は光メモリ装置に於ける光学へ・・ドに関する。[Detailed description of the invention] [Industrial application field] The present invention relates to optical data in an optical memory device.

プらに詳しくは光学ヘッドの先端部である対物レンズア
クチュエータの駆動機構、及び、全反射ミラー（又は、
全反射プリズム）の駆動機構に関する。More specifically, the drive mechanism of the objective lens actuator, which is the tip of the optical head, and the total reflection mirror (or
(Total reflection prism) drive mechanism.

〔従来技術〕[Prior art]

第２図は従来の対物レンズアクチェエータの原理を示し
た図である。ディスク１は回転にともない面ブレが生じ
、対物レンズ２はこれに追随し常にレーザー光が合焦点
となるようサーボがかけられている。即ち、レンズ横に
示した矢印の方向へボイスコイル型のリニアモータによ
って駆動される。また、ディスクの回転に伴なう情報ト
ラック３の半径方向への移動に対しては回動ミラー４が
光ビームを偏向することによってレーザー光を正しいト
ラック上に追随きせる。FIG. 2 is a diagram showing the principle of a conventional objective lens actuator. As the disk 1 rotates, surface wobbling occurs, and the objective lens 2 follows this and is servoed so that the laser beam is always in focus. That is, it is driven by a voice coil type linear motor in the direction of the arrow shown next to the lens. Further, when the information track 3 moves in the radial direction due to the rotation of the disk, the rotating mirror 4 deflects the light beam so that the laser beam follows the correct track.

第３図は他の従来例である。ディスク１０面プレ、及び
、トラック移動に対しこの方式では対物レンズ２を図の
矢印のように直角二方向に移動しレーザー光の集光及び
トラ・ｌキングを行なう、対物レンズ２の駆動方法とし
てはボイスコイル型リニアモータ、あるいは、電磁型リ
ニアモータを組合せた構成となっている。FIG. 3 shows another conventional example. In this method, the objective lens 2 is moved in two directions at right angles as shown by the arrows in the figure to focus the laser beam and track/l-king the 10th disk surface and track movement. It has a configuration that combines a voice coil type linear motor or an electromagnetic type linear motor.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

第２図に示す方式では対物レンズ２０口径は、光ビーム
の偏向に伴なう入射光束の横ズレの大きさを見込んだ径
にする必要がある。この為対物レンズが大型化するとい
う欠点がある。また、対物レンズに入射する光ビームの
入射角が変化する為に、対物レンズは球面収差の他にも
コマ収差、像面湾曲などを補正する必要があり高価にな
る。さらにはディスクからの戻り光に光ビームの偏向に
伴なう横移動が生じ、正確な集光点制御が難しい。In the system shown in FIG. 2, the aperture of the objective lens 20 needs to be set to a diameter that takes into account the size of the lateral deviation of the incident light beam due to the deflection of the light beam. This has the disadvantage that the objective lens becomes larger. Furthermore, since the angle of incidence of the light beam incident on the objective lens changes, the objective lens must be corrected not only for spherical aberration, but also for coma aberration, curvature of field, etc., making it expensive. Furthermore, the light returned from the disk undergoes lateral movement due to the deflection of the light beam, making it difficult to accurately control the focal point.

第３図に示す方式ではミラー５は固定ばれており、対物
レンズ２に入る光ビームの入射角は変化しない。この念
め対物レンズは球面収差だけを補正すればよく、第２図
に示す方式より安価になる。In the system shown in FIG. 3, the mirror 5 is fixed and the angle of incidence of the light beam entering the objective lens 2 does not change. This objective lens only needs to be corrected for spherical aberration, and is cheaper than the system shown in FIG.

しかし、光ビームの入射光束径は対物レンズの半径方向
への移動の太きはだけ対物レンズの口径を大きくする必
要があり、この為光量損失が太きくなる。シらには、対
物レンズの半径方向への移動に伴ない戻り光の横移動が
生じ、集光点の正確な制御が困難である。However, it is necessary to increase the aperture of the objective lens as the diameter of the incident light beam increases as the objective lens moves in the radial direction, which increases the loss of light quantity. Furthermore, as the objective lens moves in the radial direction, the returned light moves laterally, making it difficult to accurately control the focal point.

本発明の目的はこのような対物レンズアクチュエータの
欠点をなくし、安価であり、かつ、対物レンズにおける
光量損失が少なく、づらには、戻り光に横移動の生じな
いようにした光ヘッド対物レンズアクチュエータを提供
する事にある。The object of the present invention is to eliminate the drawbacks of such an objective lens actuator, and to provide an optical head objective lens actuator that is inexpensive, has less light loss in the objective lens, and, moreover, does not cause lateral movement of returned light. The goal is to provide the following.

〔問題点を解決する為の手段〕[Means for solving problems]

本発明による対物レンズアクチェエータは対物レンズを
光軸（フォーカス）方向に移動する第１の可動部、及び
、ディスクの半径方向（トラッキング）に移動する第２
の可動部、さらには、前記第１．第２の可動部を駆動す
る磁気回路からなり前記第１の可動部は中央に対物レン
ズ、その周辺Ｋｉｄ長７［１７）フォーカスコイル、該
フォーカスコイル上には４個のトラッキングコイルを一
体で形成し、前記コイル群を長方形の２辺に平行に置か
れた２つの磁気回路のギャップ内に挿入することによっ
て、また、前記第１の可動部は対物レンズ周辺に設けら
れた円筒状突起（ピストン）を、第２の可動部に設けら
れた円筒状ガイド（シリンダー）に嵌合することによっ
て、直交２軸のリニアモータを構成し、前記コイル群に
流す電流量、及びその方向を制御し対物レンズの光軸方
向移動、及びディスクの半径方向移動を行なうと同時に
、前記第２の可動部に固定きれた全反射ミラー（又は、
直角全反射プリズム）のディスク半径方向への移動をも
行なうことを特徴とする。The objective lens actuator according to the present invention includes a first movable part that moves the objective lens in the optical axis (focus) direction, and a second movable part that moves the objective lens in the radial direction (tracking) of the disk.
The movable part of the first. The first movable part is composed of a magnetic circuit that drives a second movable part, and the first movable part has an objective lens in the center, a focus coil with Kid length 7 [17] around it, and four tracking coils formed integrally on the focus coil. By inserting the coil group into the gap between the two magnetic circuits placed parallel to the two sides of the rectangle, the first movable part can be inserted into the cylindrical projection (piston) provided around the objective lens. ) is fitted into a cylindrical guide (cylinder) provided in the second movable part, thereby forming a linear motor with two orthogonal axes, controlling the amount of current flowing through the coil group and its direction. While moving the lens in the optical axis direction and moving the disk in the radial direction, a total reflection mirror (or
The present invention is characterized in that the right-angle total reflection prism is also moved in the radial direction of the disk.

〔作用〕[Effect]

第４図は本発明の原理を示した図である◎光ディスク１
の回転に伴なう情報トラック３の光軸方向移動に対して
は対物レンズ２を光軸方向に駆動することによって、光
ビームの集光点を追随甥せる。また、情報トラックの半
径方向の移動に対しては、光ビームの光路中に設けたミ
ラー５と対物レンズ２を光デイスク１０半径方向に同時
に駆動することによりこの変動に追随させる。駆動力の
発生にはボイスコイル型リニアモータを複数個用い、全
反射ミラーはディスクの半径方向に動く可動部に一体化
して対物レンズと共に動く構成である。Figure 4 is a diagram showing the principle of the present invention. ◎Optical disc 1
In response to the movement of the information track 3 in the optical axis direction due to the rotation of the information track 3, the focal point of the light beam can be tracked by driving the objective lens 2 in the optical axis direction. Furthermore, with respect to the movement of the information track in the radial direction, the mirror 5 and the objective lens 2 provided in the optical path of the light beam are simultaneously driven in the radial direction of the optical disk 10 to follow this movement. A plurality of voice coil type linear motors are used to generate the driving force, and the total reflection mirror is integrated into a movable part that moves in the radial direction of the disk and moves together with the objective lens.

〔実施例〕〔Example〕

第１図は本発明の組立斜視図である。対物レンズ１０は
レンズホルダー１１によって固定源れ。FIG. 1 is an assembled perspective view of the present invention. The objective lens 10 is fixed by a lens holder 11.

その周辺には長方形のフォーカシングコイル１２が巻か
れている。また、このフォーカシングコイル上には４個
のトラ−７−？フグコイル１３が図のように配置はれ固
定源れている。請求の範囲で述べた第１の可動部が上記
の部分に当り、てらに対物レンズ１０の周辺には円筒上
の突起（ピストン）１４が一体で形成されている。この
突起１４は第２可動部１５に設けられた円筒状のガイド
（シリンダ）１６に嵌め合わされる。第２の可動部１５
には４木の軸１７が固定されており、その先端は軸受１
８に挿入これる。前記トラッキングコイル１３、及びフ
ォーカシングコイル１２は、フォーカシングコイルの二
辺に平行に置かれた永久磁石１９、及びヨーク２０から
なる磁気回路のギャップ２１にそれぞれ挿入される。今
、フォーカシングコイル１２に電流ｉ１ｐ、トラッキン
グコイル１３に’［流ｉＴ　　をそれぞれ流すと、その
方向は磁界Ｈに垂直となるのでフレミングの左手の法則
によりフォーカシングコイルは上下方向の力を、また、
トラ９キングコイルは水平方向の力を受けて各々のコイ
ルが動く。従って対物レンズの移動はこの運動の合成さ
れたものとなり、２軸アクチユエータが出来上る。運動
方向の規制は第２の可動部に設けた円筒状ガイド１６と
、軸１７、及び軸受１８が行ない、対物レンズの光軸の
タオレを防いでいる。また、本発明のもう一つの特徴と
なる全反射ミラー２２はミラーホルダー２３に固定され
た後ホルダーごと前記第２の可動部１５に固定される。A rectangular focusing coil 12 is wound around it. Also, there are four tigers on this focusing coil. The blowfish coil 13 is arranged and fixed as shown in the figure. The first movable part mentioned in the claims corresponds to the above part, and a cylindrical projection (piston) 14 is integrally formed around the objective lens 10. This protrusion 14 is fitted into a cylindrical guide (cylinder) 16 provided on the second movable portion 15 . Second movable part 15
A four-wooden shaft 17 is fixed to the
This can be inserted into 8. The tracking coil 13 and the focusing coil 12 are respectively inserted into a gap 21 of a magnetic circuit consisting of a permanent magnet 19 and a yoke 20 placed parallel to two sides of the focusing coil. Now, when a current i1p is applied to the focusing coil 12 and a current iT is applied to the tracking coil 13, their direction is perpendicular to the magnetic field H, so according to Fleming's left hand rule, the focusing coil applies a force in the vertical direction, and
Each coil of the Tora 9 King Coil moves in response to horizontal force. Therefore, the movement of the objective lens is a combination of these movements, resulting in a two-axis actuator. The direction of movement is controlled by a cylindrical guide 16, a shaft 17, and a bearing 18 provided in the second movable part, and prevents the optical axis of the objective lens from becoming distorted. Further, the total reflection mirror 22, which is another feature of the present invention, is fixed to a mirror holder 23 and then fixed to the second movable part 15 together with the holder.

従って全反射ミラー２２は対物レンズ１０のトラ−、−
ｖ−ング方向の動きと共に水平方向に移動する。Therefore, the total reflection mirror 22 is the mirror of the objective lens 10.
It moves in the horizontal direction along with the movement in the v-ing direction.

この全反射ミラーは直角のプリズムを利用してもよい。This total reflection mirror may utilize a right-angled prism.

〔発明の効果〕〔Effect of the invention〕

実施例で明らかなように本発明では対物レンズと全反射
ミラー（又は、直角プリズム）が一体となってトラッ千
ング方向に移動する為、反射光の光軸移動が生ぜずレー
ザー集光点の正確な制御が可能となる。また、対物レン
ズに入射するレーザーの光軸も常にレンズの中心を通る
ので、対物レンズは球面収差のみを補正した安価なもの
でよく、さらには、対物レンズと光ビームの光束径は略
等しくすることができる為光量損失が少ない光学ヘッド
が実現する。As is clear from the examples, in the present invention, the objective lens and the total reflection mirror (or right-angle prism) move together in the tracking direction, so the optical axis of the reflected light does not shift and the laser focal point Accurate control becomes possible. In addition, since the optical axis of the laser that enters the objective lens always passes through the center of the lens, the objective lens can be an inexpensive one that corrects only spherical aberration, and furthermore, the diameters of the objective lens and the light beam should be approximately equal. As a result, an optical head with less light loss can be realized.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の実施例を示す図であり、第４図はその
動作原理図である。 第２図、第３図は従来例を示す図である。 １・・・・・・光ティスフ。 ２・・・・・・対物レンズ ６・・・・・・情報トラ・ｌり ４・・・・・・回動ミラー ５・・・・・・全反射ミラー １０・・・・・・対物レンズ １１・・・・・・レンズホルダ １２・・・・・・フォーカシングコイル１３・・・・・
・トラッキングコイル １４・・・・・・円筒状突起 １５・・・・・・可動部 １６・・・・・・ガイド １７・・・・・・軸 １８・・・・・・軸受 １９・・・・・・磁石 ２０・・・・・・ヨーク ２１・・・・・・磁気ギャップ ２２・・・・・・ミラー ２３・・・・・・ミラーホルダー 以　　上FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 4 is a diagram showing its operating principle. FIGS. 2 and 3 are diagrams showing conventional examples. 1... Light Tisph. 2...Objective lens 6...Information mirror 4...Rotating mirror 5...Total reflection mirror 10...Objective lens 11...Lens holder 12...Focusing coil 13...
・Tracking coil 14...Cylindrical protrusion 15...Movable part 16...Guide 17...Shaft 18...Bearing 19... ... Magnet 20 ... Yoke 21 ... Magnetic gap 22 ... Mirror 23 ... Mirror holder and above

Claims (1)

【特許請求の範囲】[Claims] 対物レンズを光軸（フォーカス）方向に移動する第１の
可動部、及び、ディスクの半径方向（トラッキング）に
移動する第２の可動部、さらには前記第１、第２の可動
部を駆動する磁気回路からなる対物レンズアクチュエー
タに於て、前記第１の可動部は中央に対物レンズ、その
周辺には長方形のフォーカスコイル、該フォーカスコイ
ル上には４個のトラッキングコイルを一体で形成し、前
記コイル群を長方形の２辺に平行に置かれた２つの磁気
回路のギャップ内に挿入することによってまた、前記第
１の可動部は対物レンズ周辺に設けられた円筒状突起を
、第２の可動部に設けられた円筒状ガイドに嵌合するこ
とによって、直交二軸のリニアモータを構成し、前記コ
イル群に流す電流量、及びその方向を制御し対物レンズ
の光軸方向移動、及び、ディスクの半径方向移動を行な
うと同時に、前記第２の可動部に固定された全反射ミラ
ー（又は、直角全反射プリズム）のディスク半径方向へ
の移動も行なうことを特徴とする光ヘッド対物レンズア
クチュエータ。A first movable part that moves the objective lens in the optical axis (focus) direction, a second movable part that moves in the radial direction (tracking) of the disk, and further the first and second movable parts are driven. In the objective lens actuator consisting of a magnetic circuit, the first movable part has an objective lens in the center, a rectangular focusing coil around the objective lens, four tracking coils are integrally formed on the focusing coil, and By inserting the coil group into the gap between the two magnetic circuits placed parallel to the two sides of the rectangle, the first movable part moves the cylindrical protrusion provided around the objective lens into the second movable part. By fitting into the cylindrical guide provided in the section, a linear motor with orthogonal two axes is constructed, and the amount of current flowing through the coil group and its direction are controlled, and the movement of the objective lens in the optical axis direction and the disk An optical head objective lens actuator characterized in that, at the same time as moving in the radial direction, a total reflection mirror (or a right-angle total reflection prism) fixed to the second movable part is also moved in the disk radial direction.
JP20891384A 1984-10-04 1984-10-04 Objective actuator for optical head Pending JPS6187226A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP20891384A JPS6187226A (en) 1984-10-04 1984-10-04 Objective actuator for optical head

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP20891384A JPS6187226A (en) 1984-10-04 1984-10-04 Objective actuator for optical head

Publications (1)

Publication Number Publication Date
JPS6187226A true JPS6187226A (en) 1986-05-02

Family

ID=16564188

Family Applications (1)

Application Number Title Priority Date Filing Date
JP20891384A Pending JPS6187226A (en) 1984-10-04 1984-10-04 Objective actuator for optical head

Country Status (1)

Country Link
JP (1) JPS6187226A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09180207A (en) * 1995-05-09 1997-07-11 Ricoh Co Ltd Optical head device
JP2003091846A (en) * 2001-09-20 2003-03-28 Ricoh Co Ltd Optical information recording and reproducing device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09180207A (en) * 1995-05-09 1997-07-11 Ricoh Co Ltd Optical head device
JP2003091846A (en) * 2001-09-20 2003-03-28 Ricoh Co Ltd Optical information recording and reproducing device

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