JPS59113532A - Optical information reproducer - Google Patents
Optical information reproducerInfo
- Publication number
- JPS59113532A JPS59113532A JP22420582A JP22420582A JPS59113532A JP S59113532 A JPS59113532 A JP S59113532A JP 22420582 A JP22420582 A JP 22420582A JP 22420582 A JP22420582 A JP 22420582A JP S59113532 A JPS59113532 A JP S59113532A
- Authority
- JP
- Japan
- Prior art keywords
- light
- point
- photoelectric detector
- light beam
- emitting point
- 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
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
- 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
- G11B7/0908—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 for focusing only
Landscapes
- Automatic Focus Adjustment (AREA)
- Optical Recording Or Reproduction (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は光学的情報再生ヘッド、特に焦点誤差検出手段
の改善された光学的ディスクプレーヤのごとき光学的情
報再生装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical information reproducing head, and more particularly to an optical information reproducing apparatus such as an optical disc player having improved focus error detection means.
従来例の構成とその問題点
ビテオティスクプレーヤやディジタルオーディオディス
ク(DAD )プレーヤに代表される光学式再生機はフ
ォーカス制御およびトラ、ノキング制御が必要であり、
これに用いられる光学的情報再生ヘッドは一般に光学的
な焦点誤差検出手段およびトラッキング誤差検出手段を
有する。Conventional configuration and its problems Optical playback devices, such as videotask players and digital audio disc (DAD) players, require focus control, tracking, and knocking control.
The optical information reproducing head used for this generally has optical focus error detection means and tracking error detection means.
焦点誤差検出手段としては、情報記録担体(以下、これ
を単にディスクと呼ぶ。)からの反射光を集束レンズで
集光して得られる反射光ビームに非点収差を賦与し、光
電検出器上に形成された像の非点収差量の変化を利用す
る方法が既に知られている(例えば、特開昭5Q−99
561号公報参照)。具体的には、互いに直交する2方
向の非点収差量の大きさを、4分割の受光セルを有する
光電検出器を用いて、その対角方向の受光セルの加算出
力を互いに比較することによりフォーカス誤差信号を得
るものである。As a focus error detection means, astigmatism is imparted to the reflected light beam obtained by condensing the reflected light from the information recording carrier (hereinafter simply referred to as a disk) with a focusing lens, and the resulting reflected light beam is focused on the photoelectric detector. A method is already known that utilizes changes in the amount of astigmatism of an image formed in
(See Publication No. 561). Specifically, the magnitude of astigmatism in two directions perpendicular to each other can be determined by using a photoelectric detector having four light receiving cells and comparing the summed outputs of the light receiving cells in the diagonal directions. This is to obtain a focus error signal.
一方、トラッキング誤差検出手段としては、上記反射光
束の遠視野像の光量分布のトラッキング誤差による不均
衡を、光電検出器の2つの受光セルの差動出力として検
出する方法が既に知られている(例えば、特開昭49−
80919号公報参照)0
第1図は、上記の焦点誤差検出方法およびトラッキング
誤差検出方法を用いた従来例の概略構成図である。同図
において、実質的な点光源の発光点1から放射される照
射光束2は、集束レンズ系4によってディスク5の情報
記録面上に集束されて上記発光点の共役像である読取り
光スポット9を形成する。この読取り光スポット9から
の反射光は再び集束レンズ系4で集束され、検出光束7
が得られる。上記読取り光スポット9か上記情報記録面
上に正確に焦点が合っているとき、上記検出光束7は上
記発光点1に向かって上記照射光束2の光路を逆にだと
る。そこで、上記検出光束7をビームスプリッタ3によ
り、照射光束2の光路から分離ずtLば、上記発光点1
と等測的な位置に共役像を結像するように集束する。分
離さf’した上記検出光束7の光路中に一方向性の正あ
るいは負のレンズ作用を有する円柱レンズ6を挿入する
と、−に記円柱レンズ6がレンズ作用を有する面内での
上記検出光束7の集束点1″は、上記共役像の位置から
前あるいは後に位置がずれる。上記円柱レンズ6がレン
ズ作用を有しない面内では、上記検出光束7の集束点1
′は、上記円柱レンズ6の厚みを無視すれば、上記共役
像の位置と一致するのは勿論である。上記集束点1′と
1″の間の適当な位置に光電検出8を設置す!シは、そ
の上に形成さ1シる像は、上記円柱レンズらがレンズ作
用を有する方向およびレンズ作用を有しない方向の非点
収差の極性が反対で大きさが等しくなるようにすること
かできる。このときの上記像をわかり易くするために上
記光電検出器8の拡大図を第2図に示す。同図に示すよ
うに、光電検出器8」二の像は非点収差のだめに点とは
ならず、ボケだ遠視野像10となる。ディスク5上の読
取り光スポット9の焦点751ずれた場合には、そのず
れの方向に応じて、上記遠視野像は10′あるいは10
″となる。したかつて上記光電検出器8の4つの受光セ
ル8a 、 sb 。On the other hand, as a tracking error detection means, a method is already known in which the imbalance due to a tracking error in the light intensity distribution of the far-field image of the reflected light beam is detected as a differential output of two light-receiving cells of a photoelectric detector ( For example, JP-A-49-
80919) FIG. 1 is a schematic diagram of a conventional example using the above-described focus error detection method and tracking error detection method. In the figure, an irradiation light beam 2 emitted from a light emitting point 1 of a substantial point light source is focused onto the information recording surface of a disk 5 by a focusing lens system 4, and a reading light spot 9 is a conjugate image of the light emitting point. form. The reflected light from this reading light spot 9 is again focused by the focusing lens system 4, and the detection light beam 7
is obtained. When the reading light spot 9 is accurately focused on the information recording surface, the detection light beam 7 takes the optical path of the irradiation light beam 2 toward the light emitting point 1 in the opposite direction. Therefore, if the detection light beam 7 is not separated from the optical path of the irradiation light beam 2 by the beam splitter 3, then the light emitting point 1
It is focused to form a conjugate image at a position isometric to . When a cylindrical lens 6 having a unidirectional positive or negative lens action is inserted into the optical path of the separated detection light flux 7 f', the detection light flux within the plane in which the cylindrical lens 6 has a lens action as shown in - The focal point 1'' of the detection beam 7 is shifted forward or backward from the position of the conjugate image.In the plane in which the cylindrical lens 6 has no lens action, the focal point 1'' of the detection light beam 7 is shifted forward or backward from the position of the conjugate image.
' of course coincides with the position of the conjugate image, if the thickness of the cylindrical lens 6 is ignored. A photoelectric detector 8 is installed at a suitable position between the focusing points 1' and 1''. It is also possible to make the polarities of the astigmatism in the directions opposite to each other and equal in magnitude.In order to make the above image easier to understand, an enlarged view of the photoelectric detector 8 is shown in Fig. 2. As shown in the figure, the image of the photoelectric detector 8'' does not become a point due to astigmatism, but becomes a blurred far-field image 10. When the focal point 751 of the reading light spot 9 on the disk 5 shifts, the far-field image becomes 10' or 10' depending on the direction of the shift.
''.The four light receiving cells 8a, sb of the photoelectric detector 8.
8Cおよび8dの対角どうしの和、すなわち、受光セル
8aと80の出力の和および受光セル8bと8dの出力
の和を互いに比較することにより、焦点誤差を検出する
ことができる。A focus error can be detected by comparing the sum of the diagonals of 8C and 8d, that is, the sum of the outputs of light receiving cells 8a and 80 and the sum of the outputs of light receiving cells 8b and 8d.
一方、ディスク5の情報トラック移動方向が、第2図の
Tの方向に写影されるとすれは、受光セル8aと8bの
出力の和および受光セル8Cと8dの出力の和を互いに
比較することによりトラ・ノキング誤差を検出すること
ができる。さらに寸だ、受光セル8a 、sb 、8c
および8dの出力をすべて加算することにより情報信号
を読取ることができる。On the other hand, if the information track movement direction of the disk 5 is projected in the direction of T in FIG. 2, the sum of the outputs of the light receiving cells 8a and 8b and the sum of the outputs of the light receiving cells 8C and 8d are compared with each other. This makes it possible to detect tire knocking errors. Furthermore, light receiving cells 8a, sb, 8c
The information signal can be read by adding all the outputs of 8d and 8d.
上述のように、本従来例は、1本の反射光束からフォー
カス誤差、トラッキング誤差および情報信号のすべてを
検出できるという長所を有している。ところが、円柱レ
ンズ6の焦点距離が温度変化等のために変化すると、焦
点誤差信号の検出に誤差が生ずるという問題があった0
発明の目的
本発明は、上記問題を解決し、広い温度範囲にわたって
安定な焦点誤差検出ができる光学的情報再生装置を提供
せんとするものである。As described above, this conventional example has the advantage of being able to detect all of the focus error, tracking error, and information signal from one reflected light beam. However, if the focal length of the cylindrical lens 6 changes due to changes in temperature, etc., there is a problem in that an error occurs in the detection of the focus error signal. It is an object of the present invention to provide an optical information reproducing device that can stably detect focus errors.
発明の構成
本発明の光学的情報再生装置は、点光源と、その点光源
の発光点から放射される照射光束を情報配録担体上に集
束して上記発光点の共役像である光スポットを形成する
光集束手段と、上記情報記録担体によって上記光スポッ
トから反射され、上記発光点に向かって上記光集束手段
を再び逆に通過する検出光束を上記点光源と上記光集束
手段の間で上記照射光束から分離して取り出す光分離手
段と、上記検出光束が上記発光点と光学的に等価な位置
に形成する上記発光点の共役像位置あるいはその近傍に
設置されだ光電検出器と、上記光分離手段と上記光電検
出器の間にあって、上記検出光束を上記情報記録担体の
情報トラックに実質的に略垂直な分割線によって空間的
に分割した一方の第1の部分のみを透過して他方の第2
の部分は透過しないレンズで、その主点が上記検出光束
の外側にある偏心レンズを有し、上記点光源、上記光分
離手段および上記光電検出器は熱膨張係数のほぼ均一な
固定部材で固定されており、さらに上記光電検出器は、
互いに隣接してその境界線が上記情報トラックに実質的
に略平行な第1の受光セル対と、互いに隣接してその境
界線が上記情報トラックに実質的に略垂直な2つの受光
セルから成る第2の受光セル対とを少なくとも有し、上
記検出光束の第1の部分は上記第1の受光セル対の2つ
の受光セルにほぼ等量ずつに寸だがって上記発光点の遠
視野像を形成し、上記検出光束の第2の部分は上記第2
の受光セル対の境界線上に上記発光点の共役像である近
視野像を形成するものである。上記の構成においては、
トラッキング誤差信号は上記第1の受光セル対の差動出
力として、寸だ、焦点誤差信号は上記第2の受光セル対
の差動出力としてそれぞれ得られる。したがって焦点誤
差信号は上記近視野像かも検出さizる。ざらに詳しく
言えば、上記発光点と光学的に等価な位置からの上記近
視野像のずれを検知して焦点誤差を検出するものである
。本発明では上記点光源、上記光分離手段および光電検
出器が熱膨張係数のほぼ均一な固定部材によって互いの
位置関係が固定されており、上記検出光束の第2の部分
は上記光分離手段と上記光電検出器の間で余分な光学素
子を透過しないため、上記発光点に対する光電検出器の
光学的位置関係は温度変化に対して一定に保たれ、温度
変化に対して安定な焦点誤差検出が可能となるものであ
る。Structure of the Invention The optical information reproducing device of the present invention includes a point light source and a light spot that is a conjugate image of the light emitting point by focusing the irradiation light beam emitted from the light emitting point of the point light source onto an information storage carrier. a detection light beam that is reflected from the light spot by the information recording carrier and passes back through the light focusing means toward the light emitting point, between the point light source and the light focusing means; a light separating means for separating and extracting the irradiated light beam; a photoelectric detector installed at or near a conjugate image position of the light emitting point where the detection light beam is formed at a position optically equivalent to the light emitting point; It is located between the separating means and the photoelectric detector, and the detected light beam is spatially divided by a dividing line substantially perpendicular to the information track of the information recording carrier. Second
The part is a lens that does not transmit light, and has an eccentric lens whose principal point is outside the detection light beam, and the point light source, the light separation means, and the photoelectric detector are fixed with a fixing member having a substantially uniform coefficient of thermal expansion. Furthermore, the above photoelectric detector is
consisting of a first pair of light-receiving cells that are adjacent to each other and whose boundary lines are substantially substantially parallel to the information track; and two light-receiving cells that are adjacent to each other and whose boundary lines are substantially perpendicular to the information track. a second light-receiving cell pair, the first portion of the detection light beam is sized approximately equally to the two light-receiving cells of the first light-receiving cell pair, and a far-field image of the light emitting point is formed. , and a second portion of the detection light beam forms the second
A near-field image, which is a conjugate image of the light-emitting point, is formed on the boundary line of the pair of light-receiving cells. In the above configuration,
The tracking error signal is obtained as the differential output of the first pair of light receiving cells, and the focus error signal is obtained as the differential output of the second pair of light receiving cells. Therefore, the focus error signal may also be detected as the near-field image. More specifically, the focus error is detected by detecting the shift of the near-field image from a position optically equivalent to the light emitting point. In the present invention, the point light source, the light separation means, and the photoelectric detector are fixed in position with respect to each other by a fixing member having a substantially uniform coefficient of thermal expansion, and a second portion of the detection light beam is transmitted to the light separation means and the photoelectric detector. Since no extra optical elements are transmitted between the photoelectric detectors, the optical positional relationship of the photoelectric detectors with respect to the light emitting point is kept constant against temperature changes, and stable focus error detection is possible against temperature changes. It is possible.
な訃、上記点光源としては例えば半導体レーザを用いる
ことができ、上記光分離手段としては例えばハーフミラ
−やビームスプリッタを用いることができる。捷だ、上
記偏心レンズとしては焦点距離の温度依存性の大きいプ
ラスチックレンズを用いても差支えない。For example, a semiconductor laser can be used as the point light source, and a half mirror or a beam splitter can be used as the light separation means. As the decentered lens, a plastic lens whose focal length is highly dependent on temperature may be used.
実施例の説明
以下、本発明の実施例について図面を参照しで説明する
〇
第3図は、本発明の一実施例の概略構成図である。第1
図の場合と同様に、点光源11の発光点から放射された
照射光束12は集束レンズ系14によってティスフ15
上に集束して、上記発光点の共役像である読取り光スポ
ットが形成される。DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 3 is a schematic diagram of an embodiment of the present invention. 1st
As in the case shown in the figure, the irradiation light beam 12 emitted from the light emitting point of the point light source 11 is passed through the focusing lens system 14 to the focal point 15.
The light is focused upward to form a reading light spot which is a conjugate image of the light emitting point.
上記集束レンズ系14は光集束手段を構成する。The focusing lens system 14 constitutes a light focusing means.
上記読取り光スポットからの反射光を上記集束レンズ系
14によって集束して検出光束17を得、該検出光束1
7はビームスプリッタ13によって上記照射光束12か
ら分離される。上記ビームスプリッタ13は光分離手段
を構成する。分離された検出光束17の第1の部分(図
では下半分)は、主点が上記検出光束17の外側にずれ
た偏心レンズ16によって、上記検出光束17の残りの
部分である第2の部分から空間的に分割され、光電検出
器18f:、に、上記点光源11のボケだ像、すなわち
遠視野像を形成する。The reflected light from the reading light spot is focused by the focusing lens system 14 to obtain a detection light beam 17.
7 is separated from the illumination beam 12 by a beam splitter 13. The beam splitter 13 constitutes a light separating means. The first part (lower half in the figure) of the separated detection light beam 17 is converted into a second part, which is the remaining part of the detection light beam 17, by an eccentric lens 16 whose principal point is shifted to the outside of the detection light beam 17. , and forms a blurred image of the point light source 11, that is, a far-field image, on the photoelectric detector 18f:.
一方、上記偏心レンズ16を透過しない検出光束17の
残りの第2の部分は、上記光スポットの共役像11′に
向かって集束し、光電検出器18上成する。すなわち、
光電検出器18の同一面上に、上記点光源11−の近視
野像と遠視野像が共に形成される。まだ、上記偏心レン
ズ16の主点は上記検出光束17の外側にあるため、上
記遠視野像と近視野像は空間的に分離される。On the other hand, the remaining second portion of the detection light beam 17 that does not pass through the eccentric lens 16 is focused toward the conjugate image 11' of the light spot and is formed on the photoelectric detector 18. That is,
Both a near-field image and a far-field image of the point light source 11- are formed on the same surface of the photoelectric detector 18. Since the principal point of the decentered lens 16 is still outside the detection light beam 17, the far-field image and the near-field image are spatially separated.
上記のごとく、偏心レンズ16は、」二記第1の部分に
よる光電検出器18上の像を、近視野像から遠視野像に
変換するレンズ作用とともに、上記第1の部分による遠
視野像を上記第2の部分による近視野像から空間的に分
離する作用とを合わぜ持つものである。このためには、
上記偏心レンズ16の主点が上記検出光束17の外側に
あれば、正負いずれのレンズであっても差支えない。な
お、上記主点とは、レンズの光軸上にある物点に対して
その共役像の倍率が1となるような物点位置、すなわち
光軸と主平面の交点であり、単レンズの場合、一般には
レンズの中心と呼ばノ′シる。As mentioned above, the decentered lens 16 has a lens function that converts the image on the photoelectric detector 18 by the first part from a near-field image into a far-field image, and also converts the far-field image by the first part. This also has the effect of spatially separating the near-field image from the second portion. For this purpose,
As long as the principal point of the eccentric lens 16 is outside the detection light beam 17, it may be a positive or negative lens. The principal point mentioned above is the object point position where the magnification of the conjugate image of the object point on the optical axis of the lens is 1, that is, the intersection of the optical axis and the principal plane, and in the case of a single lens. , generally called the center of the lens.
次に、焦点誤差検出およびトラッキング誤差検出につい
てさらに詳しく説明する。第4図は前記光電検出器18
の拡大図である。同図に示すように、上記光電検出器1
8は4つの受光セル18a。Next, focus error detection and tracking error detection will be explained in more detail. FIG. 4 shows the photoelectric detector 18
It is an enlarged view of. As shown in the figure, the photoelectric detector 1
8 is four light receiving cells 18a.
18b、18Cおよび18dから成り、受光セル18c
と18dは前記情報トラックが写影される方向Tにほぼ
平行な第1の境界線19bをはさんで隣接しており、受
光セル18aとiabは上記方向Tにほぼ垂直な第2の
境界線19aをはさんで隣接している。Consisting of 18b, 18C and 18d, the light receiving cell 18c
and 18d are adjacent to each other across a first boundary line 19b that is approximately parallel to the direction T in which the information track is projected, and the light receiving cells 18a and iab are adjacent to each other across a first boundary line 19b that is approximately parallel to the direction T in which the information track is projected. They are adjacent to each other with 19a in between.
読取り光スポットの焦点誤差が無いとき、第4図(a)
に示すように、上記第2の部分による近視野像20 a
が上記第2の境界線19a上に形成される。ところが、
読取り光スポットに焦点誤差が生ずると、その方向に応
じて第4図(b)の20a′あるいは第4図(c)の2
0d″のように非対称なピンボケ像に変化する。したが
って、受光セル18aと18bの出力信号を互いに比較
することにより、焦点誤差を検出することができる。ま
た、読取り光スポットの焦点が正しく合わされていると
き、上記読取り光スポットは前記点光源11の発光点の
、前記集束レンズ系14による共役像であり、さらに、
上記近視野像20 aは上記集束レンズ系14を逆に用
いたときの上記読取り光スポットの共役像であるので、
上記発光点と上記近視野像20aとは互いに光学的に等
価な位置となる。すなわち、例えば、前記光分離手段と
して、2つの直角プリズムの斜辺どうしを、反射層をは
さんで接着したビームスプリッタを用いた場合、上記発
光点と近視野像20aとは、上記ビームスプリッタの反
射面に関して互いに鏡像関係となる。したがって、上記
点光源11と上記光電検出器18の。When there is no focal error of the reading light spot, Fig. 4(a)
As shown in , the near-field image 20a from the second portion
is formed on the second boundary line 19a. However,
When a focus error occurs in the reading light spot, the focus error is 20a' in FIG. 4(b) or 20a' in FIG. 4(c) depending on the direction.
0d''. Therefore, by comparing the output signals of the light receiving cells 18a and 18b, it is possible to detect a focus error. Also, it is possible to detect whether the reading light spot is correctly focused. , the reading light spot is a conjugate image of the light emitting point of the point light source 11 by the focusing lens system 14, and further,
Since the near-field image 20a is a conjugate image of the reading light spot when the focusing lens system 14 is used in reverse,
The light emitting point and the near-field image 20a are at optically equivalent positions to each other. That is, for example, when a beam splitter in which the hypotenuses of two right-angled prisms are glued together with a reflective layer in between is used as the light separation means, the light emitting point and the near-field image 20a are based on the reflection of the beam splitter. They are mirror images of each other in terms of surfaces. Therefore, the point light source 11 and the photoelectric detector 18.
上記光分離手段に対する相対的位置関係が互いに等価で
あれば、フォーカス誤差検出は極めて安定であり、例え
ば温度変化等により上記集束レンズ系の焦点距離が変化
しても焦点誤差検出は影響を受けない。固定部材21は
熱膨張係数か均一であるため、温度変化があっても上記
点光源11と上記光電検出器18のビームスプリッタ1
3に対する相対的位置関係は等価に保たれる。If the relative positional relationship with respect to the light separation means is equivalent to each other, focus error detection is extremely stable, and even if the focal length of the focusing lens system changes due to temperature changes, for example, focus error detection will not be affected. . Since the fixed member 21 has a uniform coefficient of thermal expansion, even if there is a temperature change, the beam splitter 1 of the point light source 11 and the photoelectric detector 18
The relative positional relationship with respect to 3 is kept equivalent.
一方、前記検出光束17の第1の部分は、前記第1の境
界線19bをはさんで上記2つの受光セル18Cと18
dとにほぼ等量ずつにまたかるように遠視野像20bを
形成する。トラッキング誤差により読取り光スポットの
中心が情報トランクの中心から外れると、上記遠視野像
20bの光量分布は上記第1の境界線19bに関して非
対称となる。しだがって、上記2つの受光セル18Cと
18dの出力信号を互いに比較することにより、トラッ
キング誤差を検出することができる0また、情報信号は
、上記受光セル18 a、1 sb。On the other hand, a first portion of the detection light beam 17 is transmitted between the two light receiving cells 18C and 18 across the first boundary line 19b.
The far-field image 20b is formed so as to span approximately the same amount as d. If the center of the reading light spot deviates from the center of the information trunk due to a tracking error, the light amount distribution of the far-field image 20b becomes asymmetrical with respect to the first boundary line 19b. Therefore, by comparing the output signals of the two light-receiving cells 18C and 18d with each other, tracking errors can be detected.
18Cおよび18dの出力信号をすべて加算することに
よって検出することができる0
発明の効果
以上のように本発明は比較的簡単な構成で焦点誤差、ト
ラッキング誤差および情報信号を検出することができ、
さらに温度変化によって焦点誤差信号の検出に誤差が生
じ易いという従来の欠点を著しく改善するものである。0 can be detected by adding all the output signals of 18C and 18d. Effects of the Invention As described above, the present invention can detect focus errors, tracking errors, and information signals with a relatively simple configuration.
Furthermore, the conventional drawback that errors tend to occur in the detection of focus error signals due to temperature changes is significantly improved.
第1図は従来の光学的情報再生装置の要部概略構成図、
第2図はその従来例の部分拡大図、第3図は本発明の一
実施例の要部概略構成図、第4図(a) 、 (b)
、 (C)は同本発明の実施例の部分拡大図である0
11・・・・点光源、13・・・・・ビームスプリッタ
、14・・・・集束レンズ系、15・・・・情報記録J
’Q体、16・・・・・・偏心レンズ、18・・・・・
光電検出器。
代理人の氏名 弁理士 中 尾 敏 男 はが1名第1
図
第 3 図FIG. 1 is a schematic diagram of the main parts of a conventional optical information reproducing device.
FIG. 2 is a partially enlarged view of the conventional example, FIG. 3 is a schematic diagram of the main part of an embodiment of the present invention, and FIGS. 4(a) and (b)
, (C) is a partially enlarged view of the embodiment of the present invention.0 11...point light source, 13...beam splitter, 14...focusing lens system, 15...information Record J
'Q body, 16... Eccentric lens, 18...
Photoelectric detector. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 3
Claims (1)
を情報記録担体上に集束して上記発光点の共役像である
光スポットを形成する光集束手段と、上記情報記録担体
によって上記光スポットから反射され、上記発光点に向
かって上記光集束手段を再び逆に通過する検出光束を上
記点光源と上記光集束手段の間で上記照射光束から分離
して取り出す光分離手段と、上記検出光束が上記発光点
と光学的に等価な位置に形成する上記発光点の共役像位
置あるいはその近傍に設置された光電検出器と、上記光
分離手段と上記光電検出器の間にあって上記検出光束を
上記情報記録担体の情報トラックに実質的に略垂直な分
割線によって空間的に分割した一方の第1の部分のみを
透過して他方の第2の部分は透過しないレンズであって
、その主点が上記検出光束の外側にある偏心レンズを有
し、かつ主記点光源、上記光分離手段および上記光電検
出器は熱膨張係数のほぼ均一な固定部材で固定されてお
り、上記光電検出器は互いに隣接してその境界線が上記
情報トラックに実質的に略平行な第1の受光セル対と、
互いに隣接してその境界線が上記情報トラックに実質的
に略垂直な2つの受光セルから成る第2の受光セル対と
を少なくとも有し、上記検出光束の第1の部分は上記第
1の受光セル対の2つの受光セルにほぼ等量ずつにまた
がって上記発光点の遠視野像を形成し、上記検出光束の
第2の部分は上記第2の受光セル対の境界線上に上記発
光点の共役像である近視野像を形成するように構成した
ことを特徴とする光学的情報再生装置。a point light source, a light focusing means for focusing an irradiation light beam emitted from a generation point of the point light source onto an information recording carrier to form a light spot that is a conjugate image of the light emitting point; a light separating means for separating and extracting a detection light beam reflected from the spot and passing back through the light focusing means toward the light emitting point from the irradiation light beam between the point light source and the light focusing means; a photoelectric detector installed at or near a conjugate image position of the light emitting point where the light beam is formed at a position optically equivalent to the light emitting point; and a photoelectric detector located between the light separating means and the photoelectric detector to detect the detected light beam. A lens that is spatially divided by a dividing line substantially perpendicular to the information track of the information recording carrier and transmits only one first part and does not transmit the other second part, the principal point of which is has an eccentric lens located outside the detection light beam, and the main point light source, the light separation means, and the photoelectric detector are fixed with a fixing member having a substantially uniform coefficient of thermal expansion, and the photoelectric detector is a first pair of light-receiving cells that are adjacent to each other and whose boundaries are substantially parallel to the information track;
a second light-receiving cell pair consisting of two light-receiving cells that are adjacent to each other and whose boundaries are substantially perpendicular to the information track; A far-field image of the light-emitting point is formed across two light-receiving cells of the cell pair in approximately equal amounts, and a second portion of the detection light beam is spread over the boundary line of the second light-receiving cell pair of the light-emitting point. An optical information reproducing device characterized in that it is configured to form a near-field image that is a conjugate image.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22420582A JPS59113532A (en) | 1982-12-20 | 1982-12-20 | Optical information reproducer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22420582A JPS59113532A (en) | 1982-12-20 | 1982-12-20 | Optical information reproducer |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS59113532A true JPS59113532A (en) | 1984-06-30 |
Family
ID=16810166
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP22420582A Pending JPS59113532A (en) | 1982-12-20 | 1982-12-20 | Optical information reproducer |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS59113532A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62217425A (en) * | 1986-03-18 | 1987-09-24 | Nec Corp | Optical head device |
US5700084A (en) * | 1995-08-22 | 1997-12-23 | Hamamatsu Photonics K.K. | Optical source position adjustment device |
JP2010230405A (en) * | 2009-03-26 | 2010-10-14 | Toshiba Corp | Automatic focusing mechanism and optical image acquisition apparatus |
-
1982
- 1982-12-20 JP JP22420582A patent/JPS59113532A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62217425A (en) * | 1986-03-18 | 1987-09-24 | Nec Corp | Optical head device |
US5700084A (en) * | 1995-08-22 | 1997-12-23 | Hamamatsu Photonics K.K. | Optical source position adjustment device |
JP2010230405A (en) * | 2009-03-26 | 2010-10-14 | Toshiba Corp | Automatic focusing mechanism and optical image acquisition apparatus |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0147749B1 (en) | Optical head | |
JPS62200541A (en) | Light emitting quantity controller | |
JPS59113532A (en) | Optical information reproducer | |
JPH04134309A (en) | Focus error detection device | |
JPS6394438A (en) | Optical card recording and reproducing device | |
JPH0542736B2 (en) | ||
JPH0690817B2 (en) | Light pickup | |
JPS5812147A (en) | Reproducing head of optical information | |
JP3105613B2 (en) | Information recording / reproducing device | |
JPS5984352A (en) | Device for detecting focal error | |
JPH0656673B2 (en) | Light pickup | |
JP2594929B2 (en) | Optical information processing device | |
JPS5845629A (en) | Condensing device having focal error signal detecting function | |
JP3198161B2 (en) | Optical pickup device | |
JPS641858B2 (en) | ||
JPS62125549A (en) | Optical head | |
JPS6223373B2 (en) | ||
JPS5829151A (en) | Focus error detector in optical recorder and reproducer | |
JPS61267940A (en) | Optical head | |
JPH0770088B2 (en) | Photo detector | |
JPS63104229A (en) | Optical head device | |
JPS595441A (en) | Optical reproducing device | |
JPH0711871B2 (en) | Optical playback device | |
JPS60234236A (en) | Optical pickup device | |
JPH05274684A (en) | Optical information recording and reproducing device |