JPS621128A - Objective lens driving method - Google Patents

Abstract

PURPOSE:To make a device small in size by sharing a magnetic member which has been placed so as to be movable as one body with an objective lens, making a current flow to the first coil and the second coil which have been placed fixedly so as to be opposed to said member, and moving the objective lens in the first direction being parallel to the optical axis and the second direction being orthogonal to it. CONSTITUTION:When currents having each opposite polarity and a prescribed amplitude are made to flow to the first coils 6a, 6b, an unbalance is generated in a magnetic flux passing through a yoke 3 from permanent magnets 5-1, 5-3 and a magnetic flux passing through the yoke 3 from permanent magnets 5-2, 5-4, and a movable part containing a lens barrel 2 and the yoke 3 moves in the first direction F. Also, when currents having each opposite polarity and a prescribed amplitude in the same way are made to flow to the second coils 7a, 7b, an unbalance is generated in a magnetic flux passing through the yoke 3 from the permanent magnets 5-1, 5-2 and a magnetic flux passing through the yoke 3 from the permanent magnets 5-3, 5-4, and the movable part containing the lens barrel 2 and the yoke 3 moves in the second direction T. In this way, a magnetic circuit driven in the first direction F and a magnetic circuit driven in the second direction T are shared, therefore, a device can be made small in size.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、例えば光学式記録ディスクに記録した情報
を再生したり、このようなディスクに情報を記録すため
に対物レンズを駆動する方法に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for reproducing information recorded on an optical recording disk, for example, and for driving an objective lens for recording information on such a disk. .

〔従来の技術〕[Conventional technology]

従来、記録媒体上に光スポットを照射する対物レンズを
、その光軸と平行なフォーカシング方向およびこのフォ
ーカシング方向と直交するトラッキング方向に変位可能
に支持する手段と、対物レンズを前記フォーカシング方
向およびトラッキング方向に駆動する手段とを具える対
物レンズ駆動装置は既知であり、本願人も例えば特開昭
５５＝１４６６３６号公報において提案している。Conventionally, means for supporting an objective lens that irradiates a light spot onto a recording medium so as to be movable in a focusing direction parallel to its optical axis and in a tracking direction perpendicular to the focusing direction, and means for supporting the objective lens in the focusing direction and the tracking direction. An objective lens driving device comprising means for driving the objective lens is known, and the present applicant has also proposed it, for example, in Japanese Patent Application Laid-Open No. 146636/1983.

この本願人の提案に係る対物レンズ駆動装置においては
、フォーカシング方向およびトラッキング方向に移動可
能に支持した対物レンズ保持枠を通る磁気回路を形成す
ると共に、この磁気回路を通る磁束と交差するように対
物レンズ保持枠と対向して磁気回路を形成する固定の磁
性部材にトラッキングコイルを巻装してトラッキング駆
動手段を構成し、また対物レンズ保持枠と一体にフォー
カシング方向を中心としてフォーカシングコイルを巻装
すると共に、このフォーカシングコイルと交差する磁束
を発生する固定の磁気回路を形成していわゆるムービン
グコイル方式のフォーカシング駆動手段を構成している
。In the objective lens drive device proposed by the applicant, a magnetic circuit is formed passing through an objective lens holding frame movably supported in the focusing direction and the tracking direction, and the objective lens is moved so as to intersect with the magnetic flux passing through this magnetic circuit. A tracking coil is wound around a fixed magnetic member that faces the lens holding frame and forms a magnetic circuit to constitute a tracking drive means, and a focusing coil is wound around the focusing direction integrally with the objective lens holding frame. At the same time, a fixed magnetic circuit that generates a magnetic flux that intersects with this focusing coil is formed to constitute a so-called moving coil type focusing drive means.

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

しかし、かかる構成の対物レンズ駆動装置にあっては、
トラッキング駆動手段とフォーカシング駆動手段とを完
全に独立して別々に設けているため、装置の小形化が困
難であると共に、部品点数が多くコスト高になるという
問題がある。However, in the objective lens drive device with such a configuration,
Since the tracking drive means and the focusing drive means are provided completely independently and separately, there are problems in that it is difficult to miniaturize the device, and the number of parts is large, resulting in high costs.

この発明は、このような従来の問題点に着目してなされ
たもので、小形かつ安価に実施できる対物レンズ駆動方
法を提供することを目的とする。The present invention has been made in view of these conventional problems, and it is an object of the present invention to provide an objective lens driving method that is compact and can be implemented at low cost.

〔問題点を解決するための手段および作用〕上記目的を
達成するため、この発明では対物レンズと一体に移動可
能な磁性部材と対向して、前記対物レンズの光軸と平行
な第１の方向およびそれと直交する第２の方向を軸とし
てそれぞれ巻装した第１のコイルおよび第２のコイルを
固定し、前記磁性部材と前記第１のコイルおよび第２の
コイルとの間に前記第１のコイルおよび第２のコイルと
交差する磁束を発・生させると共に、前記第１のコイル
およびＭ２のコイルに電流を流すことにより、前記対物
レンズを前記第１の方向および第２の方向に駆動する。[Means and effects for solving the problem] In order to achieve the above object, in the present invention, a magnetic member movable integrally with the objective lens is opposed to the magnetic member in a first direction parallel to the optical axis of the objective lens. and a first coil and a second coil wound around the second direction orthogonal thereto are fixed, and the first coil and the second coil are fixed between the magnetic member and the first coil and the second coil. The objective lens is driven in the first direction and the second direction by generating a magnetic flux that intersects the coil and the second coil, and by passing a current through the first coil and the M2 coil. .

〔実施例〕〔Example〕

第１図はこの発明の一実施例を示す分解斜視図である。 FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

対物レンズ１は鏡筒２に保持し、この鏡１２を公知の支
持機構、例えば二組の平行板ばね、四本のワイヤ、一対
のスパイラルバネと一対の板ばね等によって固定部材に
対して対物レンズの光軸と平行な第１の方向Ｆおよびそ
れと直交する第２の方向Ｔとに移動可能に支持する。こ
の鏡筒２には第１の方向Ｆおよび第２の方向下と直交す
る方向に延在してヨーク３を設け、このヨーク３の両端
面にそれぞれ離間対向してブロック状のヨーク４ａ、４
ｂを固定して配置する。ヨーク４ａ。The objective lens 1 is held in a lens barrel 2, and the objective lens 12 is held against a fixed member by a known support mechanism such as two sets of parallel leaf springs, four wires, a pair of spiral springs and a pair of leaf springs. The lens is supported movably in a first direction F parallel to the optical axis of the lens and a second direction T perpendicular thereto. This lens barrel 2 is provided with a yoke 3 extending in a direction orthogonal to the first direction F and the second direction down, and block-shaped yokes 4a, 4 are provided on both end faces of the yoke 3, spaced apart from each other and facing each other.
Place b fixedly. York 4a.

４ｂ間は四本の永久磁石５−１〜５−４で連結して、各
永久磁石からの磁束がヨーク４ａ、ヨーク３およびヨー
ク４ｂを経て通るように磁気回路を形成する。また、ヨ
ーク４ａ、４ｂにはヨーク３を取る磁束と交差するよう
に第１の方向Ｆの軸のまわりに第１のコイル６ａ　、６
ｂを巻装すると共に、第２の方向下の軸のまわりに第２
のコイル７ａ、７ｂを巻装する。4b are connected by four permanent magnets 5-1 to 5-4 to form a magnetic circuit so that the magnetic flux from each permanent magnet passes through yoke 4a, yoke 3, and yoke 4b. In addition, first coils 6a, 6 are attached to the yokes 4a, 4b around the axis in the first direction F so as to intersect the magnetic flux taking the yoke 3.
b, and a second winding around the lower axis in the second direction.
The coils 7a and 7b are wound.

なお、鏡筒２Ｊ５よびヨーク３を含む可動部を第１の方
向Ｆおよび第２の方向Ｔに移動可能に支持する機構は、
その全部をヨーク４ａ、４ｂ以外の固定部材に取付けて
もよいし、その一部または全部をヨーク４ａおよび／ま
たは４ｂに取付けてもよい。Note that the mechanism that supports the movable part including the lens barrel 2J5 and the yoke 3 so as to be movable in the first direction F and the second direction T is as follows.
All of them may be attached to fixing members other than the yokes 4a and 4b, or some or all of them may be attached to the yokes 4a and/or 4b.

かかる構成において、第１のコイル６ａ　、　６ｂに互
いに逆極性で所定の振幅を有する電流を流すと、それに
よって発生する磁束によって永久磁石５−１．５−３か
らヨーク３を通る磁束と永久磁石５−２．５−４からヨ
ーク３を通る磁束とにアンバランスが生じ、鏡筒２およ
びヨーク３を含む可動部はその供給電流の振幅に応じて
第１の方向に移動する。また、第２のコイル７ａ、７ｂ
に同様に互いに逆極性で所定の振幅を有する電流を流す
と、それによって発生する磁束によって永久磁石５−１
．５−２からヨーク３を通る磁束と、永久磁石５−３．
５−４からヨーク３を通る磁束とにアンバランスが生じ
、鏡筒２およびヨーク３を含む可動部はその供給電流の
振幅に応じて第２の方向Ｔに移動する。In this configuration, when currents having opposite polarities and a predetermined amplitude are passed through the first coils 6a and 6b, the magnetic flux generated thereby causes the magnetic flux passing from the permanent magnets 5-1, 5-3 to the yoke 3 and the permanent magnets to flow. An imbalance occurs between the magnetic flux passing from 5-2 and 5-4 through the yoke 3, and the movable parts including the lens barrel 2 and the yoke 3 move in the first direction according to the amplitude of the supplied current. Moreover, the second coils 7a, 7b
Similarly, when currents with opposite polarities and a predetermined amplitude are applied to the permanent magnet 5-1, the magnetic flux generated thereby causes the permanent magnet 5-1 to
．． The magnetic flux passing through the yoke 3 from 5-2 and the permanent magnet 5-3.
An imbalance occurs in the magnetic flux passing from 5-4 through yoke 3, and the movable parts including lens barrel 2 and yoke 3 move in the second direction T according to the amplitude of the supplied current.

このように、この実施例においては第１の方向Ｆに駆動
する磁気回路と第２の方向Ｔに駆動する磁気回路とを共
用するようにしたので、装置を小形にできると共に、部
品点数を少なくでき、したがって安価にできる。In this way, in this embodiment, the magnetic circuit that drives in the first direction F and the magnetic circuit that drives in the second direction T are shared, so the device can be made smaller and the number of parts can be reduced. can be done, and therefore cheaply.

なお、この発明は上述した実施例にのみ限定されるもの
ではなく、幾多の変更または変形が可能である。例えば
、上述した実施例ではヨーク４ａ。Note that this invention is not limited only to the embodiments described above, and numerous changes and modifications are possible. For example, in the embodiment described above, the yoke 4a.

４ｂ間を四本の永久磁石５−１〜５−４で連結したが、
これら間は任意の本数の永久磁石で連結することができ
ると共に、一方のヨーク４ａまたは４ｂのみに第１およ
び第２のコイルを巻装したり、一方のヨーク４ａまたは
４ｂに第１のコイルを、使方のヨー４ｂまたは４ａに第
２のコイルを巻装してもよい。また、ヨーク３を永久磁
石としたり、ヨーク４ａおよび４ｂを永久磁石とするこ
ともできる。更に、以上の例では可動部のヨークあるい
は永久磁石よりなる磁性部材と対向して一対の固定のヨ
ークあるいは永久磁石より成る磁性部材を配置し、これ
ら固定の磁性部材間を永久磁石あるいはヨークによって
連結したが、可動部に設けた磁性部材とこれと対向する
固定の第１のコイルおよび第２のコイルとの間に、該第
１のコイルおよび第２のコイルと交差する磁束を発生さ
せれば、固定の一対の磁性部材間は必ずしも連結する必
要はない。したがって、第２図Ａに示すように、対物レ
ンズ１を有する可動部に永久磁石１１を設けると共に、
これと対向して一対の固定のヨーク１２ａ。4b were connected by four permanent magnets 5-1 to 5-4,
These can be connected by any number of permanent magnets, and the first and second coils can be wound around only one yoke 4a or 4b, or the first coil can be wound around one yoke 4a or 4b. , a second coil may be wound around the yaw 4b or 4a. Moreover, the yoke 3 can be made into a permanent magnet, and the yokes 4a and 4b can be made into permanent magnets. Furthermore, in the above example, a pair of fixed yokes or magnetic members made of permanent magnets are arranged opposite to the yokes of the movable part or magnetic members made of permanent magnets, and these fixed magnetic members are connected by the permanent magnets or yokes. However, if a magnetic flux that intersects the first coil and the second coil is generated between the magnetic member provided in the movable part and the fixed first coil and second coil facing the magnetic member, , it is not necessary to connect the pair of fixed magnetic members. Therefore, as shown in FIG. 2A, a permanent magnet 11 is provided in the movable part having the objective lens 1, and
Opposing this is a pair of fixed yokes 12a.

１２ｂを設けて、これらヨーク１２ａ　、　１２ｂに第
１のコイル１３および第２のコイル１４を巻装してもよ
い。12b may be provided, and the first coil 13 and the second coil 14 may be wound around these yokes 12a and 12b.

また、第２図Ｂに示すように可動部側にヨーク１５を、
固定部側に永久磁石ｔｅａ　、　１６ｂを同極同士が向
き合うように、あるいは異極同士が向き合うように配置
して、これら永久磁石１６ａ　、　１６ｂに第１のコイ
ル１３および第２のコイル１４を巻装してもよい。更に
、第２図Ａのように可動部に永久磁石１１を設ける場合
には、第１のコイル１３および第２のコイ）し１４は第
２図Ｃに示すように、必ずしもヨークに巻装する必要は
ない。また、第２図Ａ−Ｃにおいて、第１のコイル１３
および第２のコイル１４は可動部の磁性部材と対向する
両側にそれぞれ設けてもよいし、一方の側にのみ設けて
もよい。In addition, as shown in FIG. 2B, a yoke 15 is attached to the movable part side.
Permanent magnets 16a and 16b are arranged on the fixed part side so that the same polarity faces each other or different polarities face each other, and the first coil 13 and the second coil 14 are wound around these permanent magnets 16a and 16b. May be worn. Furthermore, when the permanent magnet 11 is provided in the movable part as shown in FIG. 2A, the first coil 13 and the second coil 14 are not necessarily wound around the yoke as shown in FIG. 2C. There's no need. In addition, in FIG. 2A-C, the first coil 13
The second coil 14 may be provided on both sides of the movable portion facing the magnetic member, or may be provided only on one side.

〔発明の効果〕〔Effect of the invention〕

以上述べたように、この発明によれば対物レンズと一体
に移動可能に配置した磁性部材を共用して、これと対向
して固定して配置した第１のコイルおよび第２のコイル
に電流を流すことにより、対物レンズを光軸と平行な第
１の方向およびそれと直交する第２の方向に移動させる
ことができるので、装置を小形にできると共に、安価に
できる。As described above, according to the present invention, a magnetic member movably arranged integrally with the objective lens is shared, and current is applied to the first coil and the second coil fixedly arranged opposite to the magnetic member. By flowing, the objective lens can be moved in a first direction parallel to the optical axis and in a second direction perpendicular thereto, so that the apparatus can be made compact and inexpensive.

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

第１図はこの発明の一実施例を示す要部の分解斜視図、 第２図Ａ−Ｃは変形例をそれぞれ示す図である。 １・・・対物レンズ　　　２・・・鏡筒３・・・ヨーク
　　　　　４ａ、　４ｂ・・・ヨーク５−１〜５−４・
・・永久磁石 ６ａ、　６ｂ・・・第１のコイル ７ａ、　７ｂ・・・第２のコイル １１・・・永久磁石　　　　１２ａ　、　１２ｂ・・・
ヨーク１３・・・第１のコイル　　１４・・・第２のｈ
イル１５・・・ヨーク　　　　　１６ａ　、　１６ｂ・
・・永久磁石特許出願人　　　オリンパス光学工業株式
会社第１図 第２図FIG. 1 is an exploded perspective view of essential parts showing one embodiment of the present invention, and FIGS. 2A to 2C are views showing modified examples, respectively. 1... Objective lens 2... Lens barrel 3... Yoke 4a, 4b... Yoke 5-1 to 5-4.
...Permanent magnets 6a, 6b...First coils 7a, 7b...Second coil 11...Permanent magnets 12a, 12b...
Yoke 13...first coil 14...second h
Ile 15... York 16a, 16b.
... Permanent magnet patent applicant Olympus Optical Industry Co., Ltd. Figure 1 Figure 2

Claims (1)

【特許請求の範囲】[Claims] １、対物レンズと一体に移動可能な磁性部材と、これと
対向して固定して設けられ、前記対物レンズの光軸と平
行な第１の方向およびそれと直交する第２の方向を軸と
してそれぞれ巻装した第１のコイルおよび第２のコイル
との間に、これら第１のコイルおよび第２のコイルと交
差する磁束を発生させると共に、前記第１のコイルおよ
び第２のコイルに電流を流すことにより、前記対物レン
ズを前記第１の方向および第２の方向に駆動することを
特徴とする対物レンズ駆動方法。1. A magnetic member movable integrally with the objective lens, fixedly provided opposite the magnetic member, with a first direction parallel to the optical axis of the objective lens and a second direction orthogonal thereto as axes, respectively. Generating a magnetic flux that intersects the first coil and the second coil between the wound first coil and the second coil, and passing a current through the first coil and the second coil. An objective lens driving method characterized in that the objective lens is driven in the first direction and the second direction.