JPH05120722A - Signal light receiving method for optical head - Google Patents
Signal light receiving method for optical headInfo
- Publication number
- JPH05120722A JPH05120722A JP3279116A JP27911691A JPH05120722A JP H05120722 A JPH05120722 A JP H05120722A JP 3279116 A JP3279116 A JP 3279116A JP 27911691 A JP27911691 A JP 27911691A JP H05120722 A JPH05120722 A JP H05120722A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- light receiving
- signal
- receiving element
- photodetector
- 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
Landscapes
- Optical Head (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、光ディスク用光ヘッド
の信号受光方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal receiving method for an optical head for an optical disk.
【０００２】[0002]
【従来の技術】光ディスク用光ヘッドは、信号光をレン
ズを用いて集光し、前記レンズの焦点位置に受光素子を
配置し、ディスクからの信号を検出するものが一般的で
ある。図５は従来の実施例を示す図面で、１はビームス
プリッタ等の光学素子、２はレンズ、３は受光素子、４
はレーザービームである。ディスクから反射されたレー
ザービーム４は、光学素子１、レンズ２を透過し、レン
ズ２の焦点位置２ａに配置した受光素子３に集光する。2. Description of the Related Art In general, an optical head for an optical disk detects a signal from a disk by condensing signal light using a lens, disposing a light receiving element at the focal position of the lens. FIG. 5 is a drawing showing a conventional embodiment, 1 is an optical element such as a beam splitter, 2 is a lens, 3 is a light receiving element, 4
Is a laser beam. The laser beam 4 reflected from the disk passes through the optical element 1 and the lens 2 and is focused on the light receiving element 3 arranged at the focal position 2 a of the lens 2.
【０００３】[0003]
【発明が解決しようとする課題】従来の光ディスク用光
ヘッドの信号受光方法では、受光素子表面に埃、汚れ等
が付着した場合、信号が著しく劣化したり、信号が再生
出来ないという事がある。本発明は、上述の欠点をなく
す事にある。In the conventional signal receiving method for an optical head for an optical disk, when dust or dirt adheres to the surface of the light receiving element, the signal may be remarkably deteriorated or the signal may not be reproduced. . The present invention avoids the above-mentioned drawbacks.
【０００４】[0004]
【課題を解決するための手段】本発明は、ディスクから
反射された信号光を、レンズを用いて受光素子に集光
し、信号検出を行う光ディスク用光ヘッドにおいて、受
光素子を前記レンズの焦点位置よりデフォーカスした位
置に配置した事を特徴とする。SUMMARY OF THE INVENTION The present invention is an optical head for an optical disc for detecting a signal by condensing signal light reflected from a disc on a light receiving element by using a lens, and focusing the light receiving element on the lens. The feature is that it is placed at a position defocused from the position.
【０００５】[0005]
（実施例１）図１は本発明の実施例を示す図で、１はビ
ームスプリッタ等の光学素子、２はレンズ、３は受光素
子、４はレーザービームである。ディスクから反射され
たレーザービーム４は、ビームスプリッタ等の光学素子
１、レンズ２を透過後、受光素子３に集光する。図２は
図１の受光素子部の詳細図である。本実施例では、受光
素子３をレンズ２の焦点位置２ａよりもレンズ２寄りに
配置している。この状態で、受光素子３のカバーガラス
３ａ表面に埃、汚れ等が付着しても、カバーガラス３ａ
上でのレーザービーム径が従来技術に比べて大きい為、
受光量損失は小さくなる。また、図３に示すように、受
光素子３を焦点位置２ａに対して、レンズ２よりも遠ざ
ける位置に配置する場合も考えられる。(Embodiment 1) FIG. 1 shows an embodiment of the present invention, in which 1 is an optical element such as a beam splitter, 2 is a lens, 3 is a light receiving element, and 4 is a laser beam. The laser beam 4 reflected from the disk passes through the optical element 1 such as a beam splitter and the lens 2, and then is focused on the light receiving element 3. FIG. 2 is a detailed view of the light receiving element portion of FIG. In this embodiment, the light receiving element 3 is arranged closer to the lens 2 than the focal position 2a of the lens 2. In this state, even if dust or dirt adheres to the surface of the cover glass 3a of the light receiving element 3, the cover glass 3a
Since the laser beam diameter above is larger than the conventional technology,
The amount of received light is reduced. Further, as shown in FIG. 3, the light receiving element 3 may be arranged at a position farther from the lens 2 than the focus position 2a.
【０００６】（実施例２）図４に示す実施例は、本発明
を光磁気ディスク用光ヘッドのＭＯ信号受光部、及び、
トラッキングエラー信号受光部に応用したものである。
レーザー発光源７から出射されたレーザービーム４は、
コリメータレンズ８、プリズム９、はね上げプリズム１
０、対物レンズ１１を透過後、ディスク１２に集光す
る。まず、ＭＯ信号受光部では、ディスク１２から反射
されたレーザービーム４は、対物レンズ１１、はね上げ
プリズム１０を透過後、プリズム９に入射し、ウォラス
トンプリズム１３、レンズ２を透過後、受光素子３に集
光する。本実施例では、受光素子３をレンズ２の焦点位
置より０．５ｍｍレンズ２側に配置することにより、受
光素子３上のビーム径を約２０μｍから約５０μｍへと
拡大させている。この結果、数十μｍの埃が付着して
も、信号を受光できる構成となっている。 また、トラ
ッキングエラー信号受光部では同様に、ディスク１２か
ら反射されたレーザービーム４は、対物レンズ１１、は
ね上げプリズム１０を透過後、プリズム９に入射し、プ
リズム１４、レンズマスク１８、レンズ１９を透過後、
受光素子２０に集光する。本実施例でも、受光素子２０
をレンズ１９の焦点位置より、レンズ１９側に配置させ
て構成している。その他にも、光磁気ディスク以外のデ
ィスクヘッドでの応用も考えられる。(Embodiment 2) An embodiment shown in FIG. 4 is a MO signal light receiving portion of an optical head for a magneto-optical disk according to the present invention, and
This is applied to the tracking error signal light receiving part.
The laser beam 4 emitted from the laser emission source 7 is
Collimator lens 8, prism 9, splash prism 1
0, after passing through the objective lens 11, it is focused on the disk 12. First, in the MO signal light receiving section, the laser beam 4 reflected from the disk 12 passes through the objective lens 11 and the flip-up prism 10 and then enters the prism 9, and after passing through the Wollaston prism 13 and the lens 2, the light receiving element 3 Focus on. In the present embodiment, the beam diameter on the light receiving element 3 is expanded from about 20 μm to about 50 μm by disposing the light receiving element 3 on the lens 2 side by 0.5 mm from the focal position of the lens 2. As a result, even if dust of several tens of μm adheres, the signal can be received. Similarly, in the tracking error signal light receiving portion, the laser beam 4 reflected from the disk 12 passes through the objective lens 11 and the flip-up prism 10 and then enters the prism 9, and passes through the prism 14, the lens mask 18, and the lens 19. rear,
The light is collected on the light receiving element 20. Also in this embodiment, the light receiving element 20
Is arranged on the lens 19 side with respect to the focal position of the lens 19. In addition, application to disk heads other than magneto-optical disks is also conceivable.
【０００７】[0007]
【発明の効果】上述のように、本発明の光ディスク用光
ヘッドは、受光素子をレンズの焦点位置よりズラして配
置し、受光素子面での収束ビームをデフォーカスするこ
とにより、埃、汚れ等の付着に対して信号受光量損失を
小さく出来、安定した信号検出が可能となる。As described above, in the optical head for an optical disk of the present invention, the light receiving element is arranged so as to be displaced from the focal position of the lens, and the converging beam on the light receiving element surface is defocused, so that dust and dirt can be obtained. It is possible to reduce the loss of the amount of light received by the signal against the adherence of the like, and it is possible to perform stable signal detection.
【図１】 本発明の実施例を示す図である。FIG. 1 is a diagram showing an embodiment of the present invention.
【図２】 本発明の実施例を示す図１の部分詳細図であ
る。FIG. 2 is a partial detailed view of FIG. 1 showing an embodiment of the present invention.
【図３】 本発明の実施例を示す図１の部分詳細図であ
る。FIG. 3 is a partial detailed view of FIG. 1 showing an embodiment of the present invention.
【図４】 本発明の実施例を示す図である。FIG. 4 is a diagram showing an example of the present invention.
【図５】 従来の実施例を示す図である。FIG. 5 is a diagram showing a conventional example.
１ 光学素子 ２、１６、１９ レンズ ２ａ 焦点位置 ３、１７、２０ 受光素子 ３ａ カバーガラス ４ レーザービーム ５ ヘッドきょう体 ６ 受光素子板 ７ レーザー発光源 ８ コリメータレンズ ９、１４ プリズム １０ はね上げプリズム １１ 対物レンズ １２ ディスク １３ ウォラストンプリズム １５ シリンドリカルレンズ １８ レンズマスク 1 optical element 2, 16 and 19 lens 2a focal position 3, 17 and 20 light receiving element 3a cover glass 4 laser beam 5 head housing 6 light receiving element plate 7 laser emission source 8 collimator lens 9 and 14 prism 10 rebound prism 11 objective lens 12 disk 13 Wollaston prism 15 Cylindrical lens 18 Lens mask
Claims (3)
ズ２を用いて受光素子３に集光し、信号検出を行う光デ
ィスク用光ヘッドにおいて、前記受光素子３を前記レン
ズ２の焦点位置２ａよりデフォーカスした位置に配置し
た事を特徴とする光ヘッドの信号受光方法。1. In an optical head for an optical disc for detecting a signal by condensing signal light reflected from a disc onto a light receiving element 3 using a lens 2, the light receiving element 3 is moved from a focal position 2a of the lens 2 A method for receiving a signal from an optical head, which is characterized in that it is arranged at a defocused position.
置したことを特徴とする請求項１記載の光ヘッドの信号
受光方法。2. The signal receiving method for an optical head according to claim 1, wherein the light receiving element 3 is arranged in a reproduction signal light receiving portion.
信号受光部に配置したことを特徴とする請求項１記載の
光ヘッドの信号受光方法。3. The signal receiving method for an optical head according to claim 1, wherein the light receiving element 3 is arranged in a tracking error signal light receiving portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3279116A JPH05120722A (en) | 1991-10-25 | 1991-10-25 | Signal light receiving method for optical head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3279116A JPH05120722A (en) | 1991-10-25 | 1991-10-25 | Signal light receiving method for optical head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05120722A true JPH05120722A (en) | 1993-05-18 |
Family
ID=17606648
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3279116A Pending JPH05120722A (en) | 1991-10-25 | 1991-10-25 | Signal light receiving method for optical head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05120722A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7150568B2 (en) | 2003-02-06 | 2006-12-19 | Seiko Epson Corporation | Light-receiving element, manufacturing method for the same, optical module, and optical transmitting device |
| US7307250B2 (en) | 2003-02-06 | 2007-12-11 | Seiko Epson Corporation | Light-receiving element and manufacturing method of the same, optical module and optical transmitting device |
-
1991
- 1991-10-25 JP JP3279116A patent/JPH05120722A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7150568B2 (en) | 2003-02-06 | 2006-12-19 | Seiko Epson Corporation | Light-receiving element, manufacturing method for the same, optical module, and optical transmitting device |
| US7307250B2 (en) | 2003-02-06 | 2007-12-11 | Seiko Epson Corporation | Light-receiving element and manufacturing method of the same, optical module and optical transmitting device |
| US7520680B2 (en) | 2003-02-06 | 2009-04-21 | Seiko Epson Corporation | Light-receiving element, manufacturing method for the same, optical module, and optical transmitting device |
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