JPS5873025A - Optical information reproducer using laser diode as light source - Google Patents
Optical information reproducer using laser diode as light sourceInfo
- Publication number
- JPS5873025A JPS5873025A JP56171714A JP17171481A JPS5873025A JP S5873025 A JPS5873025 A JP S5873025A JP 56171714 A JP56171714 A JP 56171714A JP 17171481 A JP17171481 A JP 17171481A JP S5873025 A JPS5873025 A JP S5873025A
- Authority
- JP
- Japan
- Prior art keywords
- light
- laser diode
- intensity distribution
- light beam
- light intensity
- 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
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
Abstract
Description
【発明の詳細な説明】
本発明はレーザーダイオードから発生する光ビームにて
凹凸状態に記録した情報を再生する光学的情報再生装置
に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical information reproducing device that reproduces information recorded in an uneven state using a light beam generated from a laser diode.
レーザーダイオードは温度によって発光部の屈折率変化
により波面が時間と共に変化し、発生光ビームの光強度
分布がｖＪｓ図のように変化し、光量の最大値がＮから
Ｎ′あるいはＮ“へと移動する・すると複数の光電素子
よりなる、所謂差動型光電素子１２’を使用し、隣り合
う光電素子の光量差により情報媒体上のビームスポット
の時信号を検出するものでは、光ビームの光強度分布の
変化が、差動型光電素子１２’上でのビームスボッ）
ｌ ５’、第６図（ａ）、（ｂ）のようにあられれ、差
動型光電素子１２’の検出信号に直流バイアス的変化を
与え、前記ビームスポットの各種制御信号の検出に悪影
響を与えるという欠点が生じる。In a laser diode, the wavefront changes over time due to changes in the refractive index of the light emitting part due to temperature, and the light intensity distribution of the generated light beam changes as shown in the vJs diagram, and the maximum value of the light amount moves from N to N' or N''. Then, in a method that uses a so-called differential photoelectric element 12' consisting of a plurality of photoelectric elements and detects a signal at a beam spot on an information medium based on the difference in light intensity between adjacent photoelectric elements, the light intensity of the light beam is The change in the distribution causes the beam spot on the differential photoelectric element 12'.
5', as shown in FIGS. 6(a) and 6(b), which gives a DC bias-like change to the detection signal of the differential photoelectric element 12' and adversely affects the detection of various control signals of the beam spot. The disadvantage of giving arises.
本発明は上記の点に鑑みて、レーザーダイオードからの
発生光ビームの光強度分布が温度によって変化しても、
差動型光電素子による制御信号の検出に悪影響を与えな
いようにしたレーザーダイオードを光源に使用する光学
的情報再生装置を提供することを目的とする。In view of the above points, the present invention has been developed so that even if the light intensity distribution of the light beam generated from the laser diode changes depending on the temperature,
An object of the present invention is to provide an optical information reproducing device using a laser diode as a light source that does not adversely affect detection of a control signal by a differential photoelectric element.
以下本発明の好適な実施例を図面に従い説明するＯ
第１図に示すように、レーザーダイオード１から発する
光ビーム２は、レンズ８、偏光ビームスプリッタ−４，
４分の１波長板５、反射体６及び集束レンズ７を経て情
報媒体８上にビームスポット９として集束される。そし
て情報媒体８の凹凸ビットの光干渉による回折を受けた
反射光ビームｌＯは、前記集束レンズ７、反射体６．４
分Ｏ１波長板５にて偏光ビームスプリッタ−４に達１．
、前記光ビーム２０光軸と直角方向に偏向され、レンズ
ｔｔｔ−ｓて、差動型光電素子１２の受光面を照射する
〇
この際、前記光ビーム２あるいは反射光ビーム１０の任
意の光路中で、しかもこれら光ビーム２、ｌＯの光軸Ｘ
中央部の光を遮断する。最屯製造が容易な方法としては
、レンズ畠、１１及び集束レンズｉ轡のレンズの中央部
に光遮断加工をすることが考えられ、具体的には、レン
ズ製造工程中、芯出加工の研削時にレンズの中央部分も
同時に研削し、この研削部分に塗料等をぬる様にする方
法がある＠
このような構成のため、ビームスポット９の光強度の最
大値Ｍ付近を遮断することになる。このことはレーザー
ダイオード１よ妙見する光ビーム２の光強度分布が温度
によって変化したとしても、反射光ビームｌＯが前記差
動型光電素子１２の受光面を照射する時に生じるビーム
スポット１５においても光強度分布の最大値部分（第８
図）が遮断されることから、この光強度分布の変化が差
動型光電素子１２による信号検出に大きな影響を与えな
いことＫなる。すなわち第２図のように情報媒体８上の
ビームスポット９はピッ）１４外に照射する部分９ａと
中央部９ｂとの光干渉を受けるが、９ａの部分の光干渉
による回折効果の影響を強く愛社、光ビーム２．１０の
光軸中央部の光を遮断してビームスポット１５の全体光
量が減じたとしても、各種信号の検出にはさ＃１ど影響
を与えるものでない。Preferred embodiments of the present invention will be described below with reference to the drawings. As shown in FIG.
The beam passes through a quarter-wave plate 5, a reflector 6, and a focusing lens 7, and is focused onto an information medium 8 as a beam spot 9. The reflected light beam lO that has been diffracted by optical interference of the concave and convex bits of the information medium 8 is directed to the converging lens 7 and the reflector 6.4.
The polarizing beam splitter 4 is reached at the wavelength plate 5.1.
, the light beam 20 is deflected in a direction perpendicular to the optical axis and irradiates the light receiving surface of the differential photoelectric element 12 with the lens ttt-s. At this time, in any optical path of the light beam 2 or the reflected light beam 10, Moreover, the optical axis X of these light beams 2 and lO
Block out light in the center. One of the easiest methods to manufacture is to apply a light blocking process to the central part of the lens 11 and the focusing lens. Specifically, during the lens manufacturing process, grinding for centering process is considered. Sometimes, there is a method in which the central part of the lens is also ground at the same time, and this ground part is coated with paint, etc. With this configuration, the vicinity of the maximum value M of the light intensity of the beam spot 9 is blocked. This means that even if the light intensity distribution of the light beam 2 observed by the laser diode 1 changes depending on the temperature, the beam spot 15 that is generated when the reflected light beam 10 illuminates the light receiving surface of the differential photoelectric element 12 will still have light. Maximum value part of intensity distribution (8th
(Fig.) is blocked, this change in the light intensity distribution does not have a large effect on signal detection by the differential photoelectric element 12. In other words, as shown in FIG. 2, the beam spot 9 on the information medium 8 is subjected to optical interference between the outwardly irradiated portion 9a and the central portion 9b, but the diffraction effect due to the optical interference in the portion 9a is strongly influenced. Even if the overall light intensity of the beam spot 15 is reduced by blocking the light at the center of the optical axis of the light beam 2.10, it will not affect the detection of various signals in the first place.
−ｈ記実施例では、レンズの中央部に光遮断部１８を形
成して説明したが、光遮断方法としては種々のものが考
えられる。-h In the embodiment described above, the light blocking portion 18 was formed in the center of the lens, but various methods of blocking light can be considered.
本発明は上記の如く構成したため、レーザーダイオード
の発生光ビームが温度変化に伴ないその光強度分布を変
化しても、差動型光電素子による信号検出に影響を４え
ないようにできる郷の効果がある。Since the present invention is configured as described above, even if the light intensity distribution of the light beam generated by the laser diode changes due to temperature change, it is possible to prevent the signal detection by the differential photoelectric element from being affected. effective.
第１図は本発明の実施例の光学系を示す図、第２図は情
報媒体上でのビームスポットとビットとの関係を示す図
、第８−は本発明の遮断効果と光ビームの光強度分布の
変化を説明するための図、第４図は差動型光電素子上で
のビームスポットの遮断効果を説明するための図、第５
図はレーザーダイオードの発生光ビームの発生光ビーム
の＠度変化により生じる光強度分布の変化を示す説明図
、第６図（ａ）、第６図（ｂ）は光ビームの光強度分布
の変化が差動型光電素子上のビームスポットの光量分布
に変化を与えることを示す説明図である。
１−・レーザーダイオード、２、ｌＯ・・光ビーム、８
・・情報媒体、９・・ビームスポット、Ｘ・・光ビーム
の光軸□
特許出願人 萬世工業株式会社FIG. 1 is a diagram showing the optical system of the embodiment of the present invention, FIG. 2 is a diagram showing the relationship between the beam spot and the bit on the information medium, and FIG. Figure 4 is a diagram for explaining the change in intensity distribution, Figure 4 is a diagram for explaining the beam spot blocking effect on the differential photoelectric element, and Figure 5 is a diagram for explaining the effect of blocking the beam spot on the differential photoelectric element.
The figure is an explanatory diagram showing the change in the light intensity distribution caused by the degree change of the light beam generated by the laser diode. Figures 6 (a) and 6 (b) are the changes in the light intensity distribution of the light beam. FIG. 3 is an explanatory diagram showing that the light intensity distribution of a beam spot on a differential photoelectric element changes. 1- Laser diode, 2, lO... Light beam, 8
...Information medium, 9..Beam spot, X..Optical axis of light beam□ Patent applicant Mansei Kogyo Co., Ltd.
Claims (1)
レーザーダイオード（１）から発生した光ビーム（２）
を光学系を介してビームスポット（９）として集束し、
前記凹凸との光干渉による光回折効果にて生じる光学的
変化を差動型光電素子（１２）に入射して、情報信号及
び前記ビームスポット（９）の制御信号を検出する光学
的情報再生装置において、前記レーザーダイオード（１
）から差動型光電素子（１２）へ光学系を介して照射す
る光ビーム（２，１０）の光軸（Ｘ）の中心部分を光遮
断してなるレーザーダイオードを光源に使用した光学的
情報再生装置。1. On the information medium (8) on which information is recorded through unevenness,
Light beam (2) generated from laser diode (1)
is focused as a beam spot (9) through an optical system,
An optical information reproducing device that detects an information signal and a control signal for the beam spot (9) by inputting an optical change caused by a light diffraction effect due to light interference with the unevenness into a differential photoelectric element (12). In the laser diode (1
) to the differential photoelectric element (12) via an optical system. Optical information using a laser diode as a light source, which is formed by blocking the central part of the optical axis (X) of the light beam (2, 10). playback device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56171714A JPS5873025A (en) | 1981-10-27 | 1981-10-27 | Optical information reproducer using laser diode as light source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56171714A JPS5873025A (en) | 1981-10-27 | 1981-10-27 | Optical information reproducer using laser diode as light source |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5873025A true JPS5873025A (en) | 1983-05-02 |
Family
ID=15928310
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56171714A Pending JPS5873025A (en) | 1981-10-27 | 1981-10-27 | Optical information reproducer using laser diode as light source |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5873025A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0589007U (en) * | 1992-05-06 | 1993-12-03 | 関東自動車工業株式会社 | Trolley for tire mounting |
-
1981
- 1981-10-27 JP JP56171714A patent/JPS5873025A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0589007U (en) * | 1992-05-06 | 1993-12-03 | 関東自動車工業株式会社 | Trolley for tire mounting |
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