JPH0287961A - Linear actuator - Google Patents
Linear actuatorInfo
- Publication number
- JPH0287961A JPH0287961A JP24143488A JP24143488A JPH0287961A JP H0287961 A JPH0287961 A JP H0287961A JP 24143488 A JP24143488 A JP 24143488A JP 24143488 A JP24143488 A JP 24143488A JP H0287961 A JPH0287961 A JP H0287961A
- Authority
- JP
- Japan
- Prior art keywords
- coil
- permanent magnet
- linear actuator
- flux density
- optical axis
- 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
Links
- 230000004907 flux Effects 0.000 claims abstract description 16
- 230000003287 optical effect Effects 0.000 abstract description 22
- 230000000087 stabilizing effect Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
Landscapes
- Optical Recording Or Reproduction (AREA)
- Reciprocating, Oscillating Or Vibrating Motors (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はリニアアクチュエータに関し、特に光ディスク
等に使用される対物レンズアクチュエータに関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a linear actuator, and particularly to an objective lens actuator used for optical discs and the like.
リニアアクチュエータは直線移動手段として例えば光デ
イスク装置の対物レンズアクチュエータ等広く使用され
る。Linear actuators are widely used as linear moving means, such as objective lens actuators in optical disk devices.
本発明は一般のリニアアクチュエータに適用されるもの
であるが、以下の説明は一例として光デイスク装置の対
物レンズアクチュエータについて行う。Although the present invention is applied to a general linear actuator, the following description will be made regarding an objective lens actuator of an optical disk device as an example.
従来、この種の対物レンズアクチュエータは、光デイス
ク面に光スポットを正確にあてるため、フォーカスを調
整するフォーカシングと位置ずれを調整するトラッキン
グを行なう。このため、対物レンズアクチュエータは、
磁力線を発生する永久磁石と、光軸方向に駆動力を発生
するフォーカシングコイルおよび光軸に対し垂直方向に
駆動力を発生するトラッキングコイルの２つのコイルと
、そのコイルの駆動力に対し、反力を発生するバネ材と
を有している。Conventionally, this type of objective lens actuator performs focusing to adjust focus and tracking to adjust positional deviation in order to accurately apply a light spot to the optical disk surface. For this reason, the objective lens actuator is
A permanent magnet that generates magnetic lines of force, a focusing coil that generates a driving force in the direction of the optical axis, and a tracking coil that generates a driving force perpendicular to the optical axis, and a reaction force to the driving force of the coil. It has a spring material that generates.
第６図に、従来例の外観図を示す。FIG. 6 shows an external view of a conventional example.
レンズホルダ２０は、棒状のバネ材１０によって支持さ
れ、対物レンズ１を保持している。レンズホルダ２０に
設けられた開口穴内には、ヨーク２Ａ、２Ｂが、これら
ヨーク２Ａ、２Ｂと対向位置には永久磁石１３Ａ、１３
Ｅが配設されており、レンズホルダの永久磁石１３Ａ、
１３Ｂの対向部および側部に設けられたトラックコイル
４ａ、４ｂ。The lens holder 20 is supported by a rod-shaped spring member 10 and holds the objective lens 1. In the opening hole provided in the lens holder 20, there are yokes 2A and 2B, and in positions facing these yokes 2A and 2B, there are permanent magnets 13A and 13.
E is arranged, and the permanent magnet 13A of the lens holder,
Track coils 4a, 4b provided on the opposing and side parts of 13B.
５ａ、５ｂおよびフォーカスコイル６との磁気作用によ
りレンズのトラッキング移動およびフォーカシング移動
が行われる。第４図にトラックコイル４ａ、４ｂと永久
磁石による磁界の関係を示す。5a, 5b and the focusing coil 6, tracking movement and focusing movement of the lens are performed. FIG. 4 shows the relationship between the track coils 4a, 4b and the magnetic fields generated by the permanent magnets.
上述した従来の対物レンズアクチュエータは、次のよう
な問題点がある。The conventional objective lens actuator described above has the following problems.
トラックコイル４ａ、４ｂ、５ａ、５ｂは、永久磁石１
３ａ、１３ｂの発生する磁界において、２つの方向の電
流成分、即ち、トラッキングのための駆動力となる光軸
に平行な成分（Ｘ方向）と、光軸方向と垂直方向の成分
（Ｘ方向）とをもつ（第４図参照）。一般に、Ｘ方向（
光軸と直角方向）に流れる電流成分は、コイルの対向辺
で互いに逆方向であるため両型流により生ずる磁気力は
互いに相殺されなげればならない。このため、第７図に
示す永久磁石の磁束密度の分布に対し、第８図Ａのよう
な関係でコイルを配置している。しかし、フォーカシン
グ等の動作により、トラックコイル４ａ、４ｂ、５ａ、
５ｂの光軸方向の移動が起き、第８図ＢまたはＣのよう
に磁石中心からコイル中心位置がずれると、トラックコ
イル４ａ。Track coils 4a, 4b, 5a, 5b are permanent magnets 1
In the magnetic fields generated by 3a and 13b, there are two current components in two directions: a component parallel to the optical axis (X direction) that serves as a driving force for tracking, and a component perpendicular to the optical axis direction (X direction). (See Figure 4). Generally, the X direction (
Since the current components flowing in directions perpendicular to the optical axis are in opposite directions on opposite sides of the coil, the magnetic forces generated by both types of flow must cancel each other out. For this reason, the coils are arranged in a relationship as shown in FIG. 8A with respect to the distribution of magnetic flux density of the permanent magnet shown in FIG. 7. However, due to operations such as focusing, the track coils 4a, 4b, 5a,
5b in the optical axis direction and the coil center position deviates from the magnet center as shown in FIG. 8B or C, the track coil 4a.
４ｂ、５ａ、５ｂの２つの辺で、異なる大きさの磁気力
が発生し、モーメントにより、対物レンズア名チュエー
タにずれが生じる。Magnetic forces of different magnitudes are generated on the two sides 4b, 5a, and 5b, and the moment causes a shift in the objective lens aperture.
本発明のリニアアクチュエータは、永久磁石とその永久
磁石に対向するヨークに挟まれた空間内に前記永久磁石
に対向して設置されたコイルに流れる電流と前記永久磁
石により生ずる磁界との電磁力により前記コイルを移動
せしめるリニアアクチュエータにおいて、前記永久磁石
は、前記コイルに対して双頭状磁束密度分布を与えるよ
うに、構成されている。The linear actuator of the present invention is produced by an electromagnetic force between a current flowing through a coil that is installed facing the permanent magnet in a space between a permanent magnet and a yoke facing the permanent magnet, and a magnetic field generated by the permanent magnet. In the linear actuator that moves the coil, the permanent magnet is configured to provide a double-headed magnetic flux density distribution to the coil.
次に本発明について、図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.
第１図は本発明の一実施例の斜視図を示す。FIG. 1 shows a perspective view of an embodiment of the invention.
レンズホルダ２０に取付けられた対物レンズ１は、その
光軸方向及び光軸と直交する方向（トラッキング方向）
に移動可能に４本のバネ１０により、ベース１００に保
持されている。The objective lens 1 attached to the lens holder 20 has an optical axis direction and a direction perpendicular to the optical axis (tracking direction).
It is held on a base 100 by four springs 10 so as to be movable.
対物レンズ光軸と直交する方向に磁極を有する永久磁石
３Ａ、３Ｂが対物レンズ光軸を挟持する様に配置され、
永久磁石３Ａ、３Ｂとセンタヨーク２Ａ、２Ｂの間に矩
形状に巻き込んだトラックコイル４ａ、４ｂ及び５ａ５
ｂが配設されている。Permanent magnets 3A and 3B having magnetic poles in a direction perpendicular to the optical axis of the objective lens are arranged to sandwich the optical axis of the objective lens,
Track coils 4a, 4b and 5a5 wound in a rectangular shape between permanent magnets 3A and 3B and center yokes 2A and 2B.
b is provided.
永久磁石３Ａ、３Ｂには対物レンズ１の光軸と直交する
方向で、トラックコイル３Ａ、３Ｂの光軸方向中心位置
近傍に矩形ミゾが形成されている。A rectangular groove is formed in the permanent magnets 3A, 3B in a direction perpendicular to the optical axis of the objective lens 1, near the center position of the track coils 3A, 3B in the optical axis direction.
上記構成により得られる永久磁石３Ａ、３Ｂの磁束密度
分布は、第２図に、示す実測値より矩形ミゾを形成した
事により中心部近傍の磁束密度が凹状に減少する。これ
より、第３図Ａに示す様に、前記磁束密度分布の中のト
ラックフィルが磁束密度分布の中心にある場合と、第３
図Ｃ下方向にある場合及び第３図Ｃ下方向にある場合、
それぞれにおいて図中トラックフィル上方断面部と、下
方断面部に受ける磁束密度の変化が少なくなる。したが
って第４図に示す様にトラックコイルに電流が流れる事
により発生するモーメントを第５図に示すがモーメン）
Ｍ＋及びモーメン）Ｍｔに差が少なくなり、レンズホル
ダ２０に発生する不用な回転モーメントは極めて少なく
なり、トラックコイルに光軸と平行に電流が流れる事に
より発生する光軸と直交する力の成分のみが有効となり
良好なトラッキング動作特性が得ら九る。In the magnetic flux density distribution of the permanent magnets 3A and 3B obtained with the above configuration, the magnetic flux density near the center decreases in a concave manner due to the formation of the rectangular groove, as compared to the measured value shown in FIG. From this, as shown in FIG. 3A, the track fill in the magnetic flux density distribution is at the center of the magnetic flux density distribution, and the third
If it is located at the bottom of Figure C, or if it is located at the bottom of Figure 3,
In each case, the change in magnetic flux density applied to the upper cross-sectional portion and the lower cross-sectional portion of the track fill in the figure is reduced. Therefore, as shown in Fig. 4, the moment generated when current flows through the track coil is shown in Fig. 5 (moment).
The difference in Mt (M+ and moment) is reduced, the unnecessary rotational moment generated in the lens holder 20 is extremely reduced, and only the force component perpendicular to the optical axis generated by the current flowing in the track coil parallel to the optical axis is reduced. becomes effective and good tracking performance characteristics can be obtained.
以上説明した様に本発明は、トラックフィルを挟持する
永久磁石にミゾを形成するという簡単な構成で磁束密度
を大きく減少させる事なく、良好なトラッキング動作特
性を有する対物レンズアクチュエータを提供できる効果
がある。As explained above, the present invention has the effect of providing an objective lens actuator with good tracking operation characteristics without greatly reducing the magnetic flux density with a simple structure of forming grooves in the permanent magnets that sandwich the track fill. be.
なお、本発明の効果は、実施例によるアクチュエータ構
成のみならず、本例同様光軸方向と直交する磁極を有す
る対物レンズアクチュエータで光軸と平行に配置した矩
形状及びリング状のトラックコイルを該永久磁石の発生
する磁束中に配置してトラッキング動作を行う構成のア
クチュエータにはすべて同様の効果が得られる事は言う
までもない。Note that the effects of the present invention are not limited to the actuator configuration according to the embodiments, but also apply to rectangular and ring-shaped track coils arranged parallel to the optical axis using an objective lens actuator having a magnetic pole perpendicular to the optical axis direction as in this example. It goes without saying that the same effect can be obtained with any actuator configured to perform a tracking operation by being placed in the magnetic flux generated by a permanent magnet.
さらに永久磁石に形成するミゾは、その形を変化させる
事も容易である。Furthermore, the shape of the grooves formed on the permanent magnet can be easily changed.
以上説明したように本発明は、単に永久磁石の形状を変
えただけでリニアアクチュエータの動作を安定できると
いう効果がある。As explained above, the present invention has the effect of stabilizing the operation of the linear actuator simply by changing the shape of the permanent magnet.
第１図は本発明の上方斜視図、第２図は本発明の永久磁
石の磁束密度分布図、第３図は本発明の磁束密度分布中
のトラックコイル配置を示す説明図４第４図はトラック
コイルの光軸方向に対する電流の流れを示す説明図、第
５図はトラックコイルに発生する回転モーメントを示す
説明図、第６図は、従来例の上方斜視図、第７図は従来
例の永久磁石の磁束密度分布図、第８図は、従来例の磁
束密度分布中のトラックコイル配置を示す説明図。
１・・・・・対物レン７’：’、２Ａ、２Ｂ・・・・・
・センタヨーク、３Ａ、３］１１・＝永久磁石、４ａ、
４ｂ、５ａ。
５ｂ・・・・・・トラックコイル、６・・・・・・フォ
ーカスコイル、１０・・・・・・バネ、２０・・・・・
・レンズホルダ、１００・・・・・・ベース
代理人 弁理士 内 原 晋
茅３ ＠
華
回
牛
乙
凹FIG. 1 is an upper perspective view of the present invention, FIG. 2 is a magnetic flux density distribution diagram of the permanent magnet of the present invention, and FIG. 3 is an explanatory diagram showing the track coil arrangement in the magnetic flux density distribution of the present invention. FIG. 5 is an explanatory diagram showing the flow of current in the optical axis direction of the track coil, FIG. 5 is an explanatory diagram showing the rotational moment generated in the track coil, FIG. 6 is an upper perspective view of the conventional example, and FIG. 7 is an explanatory diagram of the conventional example. FIG. 8 is an explanatory diagram showing the arrangement of track coils in the magnetic flux density distribution of a conventional example. 1...Objective lens 7':', 2A, 2B...
・Center yoke, 3A, 3] 11・=Permanent magnet, 4a,
4b, 5a. 5b...Track coil, 6...Focus coil, 10...Spring, 20...
・Lens holder, 100...Base agent Patent attorney Shinsou Uchihara 3
Claims (3)
れた空間内に、前記永久磁石に対向して設置されたコイ
ルに流れる電流と前記永久磁石により生ずる磁界との電
磁力により前記コイルを移動せしめるリニアアクチュエ
ータにおいて、前記永久磁石は前記コイルに対して双頭
状磁束密度分布を与えるように構成されていることを特
徴とするリニアアクチュエータ。(1) In a space between a permanent magnet and a yoke facing the permanent magnet, the coil is activated by the electromagnetic force of the current flowing through a coil installed facing the permanent magnet and the magnetic field generated by the permanent magnet. A linear actuator for movement, characterized in that the permanent magnet is configured to give a double-headed magnetic flux density distribution to the coil.
の電流成分を流す第１の電線部分と、駆動力には無関係
のため発生する力を互いに相殺しあうように対向して設
けられている第２および第３の電線部分とを有するリニ
アアクチュエータにおいて、駆動しない状態で前記第２
および第３の電線部分に前記双頭状磁束密度分布の頭部
が存在することを特徴とする請求項（１）記載のリニア
アクチュエータ。(2) The coil is provided opposite to the first electric wire portion through which a current component for generating a driving force flows in the space so that the generated forces cancel each other out because they are unrelated to the driving force. In the linear actuator having second and third electric wire portions, the second and third electric wire portions are
The linear actuator according to claim 1, wherein the head of the double-headed magnetic flux density distribution is present in the third electric wire portion.
電線成分に沿う凹部を設けたことを特徴とする請求項（
１）又は（２）記載のリニアアクチュエータ。(3) A recessed portion along the first wire component of the coil is provided in the surface portion of the permanent magnet (
The linear actuator according to 1) or (2).
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24143488A JPH0287961A (en) | 1988-09-26 | 1988-09-26 | Linear actuator |
| US07/412,717 US5073882A (en) | 1988-09-26 | 1989-09-26 | Servo-controlled actuator with two-peak flux density distribution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24143488A JPH0287961A (en) | 1988-09-26 | 1988-09-26 | Linear actuator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0287961A true JPH0287961A (en) | 1990-03-28 |
Family
ID=17074247
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24143488A Pending JPH0287961A (en) | 1988-09-26 | 1988-09-26 | Linear actuator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0287961A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100486272B1 (en) * | 2002-10-15 | 2005-04-29 | 삼성전자주식회사 | An optical pickup actuator and an optical disk drive using the same |
| KR100510539B1 (en) * | 2003-08-05 | 2005-08-26 | 삼성전자주식회사 | Magnet having depressed pattern and Optical pickup actuator comprising the same |
| JP2017184600A (en) * | 2016-03-29 | 2017-10-05 | リコーイメージング株式会社 | Stage device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6126976A (en) * | 1984-07-17 | 1986-02-06 | Toshiba Corp | Magnetic disk device |
-
1988
- 1988-09-26 JP JP24143488A patent/JPH0287961A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6126976A (en) * | 1984-07-17 | 1986-02-06 | Toshiba Corp | Magnetic disk device |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100486272B1 (en) * | 2002-10-15 | 2005-04-29 | 삼성전자주식회사 | An optical pickup actuator and an optical disk drive using the same |
| KR100510539B1 (en) * | 2003-08-05 | 2005-08-26 | 삼성전자주식회사 | Magnet having depressed pattern and Optical pickup actuator comprising the same |
| JP2017184600A (en) * | 2016-03-29 | 2017-10-05 | リコーイメージング株式会社 | Stage device |
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