JPS60169721U

JPS60169721U - Optical information reproducing device

Info

Publication number: JPS60169721U
Application number: JP4167185U
Authority: JP
Inventors: 近藤　光重
Original assignee: 三菱電機株式会社
Priority date: 1985-03-22
Filing date: 1985-03-22
Publication date: 1985-11-11

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of drawings]

第１図はこの考案の一実施例を示し、第１図ａは系統図
、第１図すは光検知装置の一例を示す正面図、第２図は
焦点ずれ信号の発生を示す系統図、第３図は第２図に示
すそれぞれの場合における光検知装置と光束との関係を
示す正面図、第４図は反射光束と光検知装置との関係を
示す縦断面図、第５図は第４図に対応する横断面図、第
６図はこの考案に用いる光検知装置の他の例を示す斜視
図、第７図はこの考案の他の実施例を示すブロック線図
である。図において、３はハーフミラ−１５は集光レンズ、８１
はハーフミラ−（第１の分光装置）、８２はハーフミラ
−（第２の分光装置）、２２は第１の光検知装置、２３
は第２の光検知装置、１２は駆動制御装置、３１は差動
増幅器、４１はスリット、４２．４３はそれぞれ補償装
置である。なお各図中同一符号は同−又は相当部分を示
すものとする。ｌ　　ｑｌ第４目第５目１１、。　　第６目３１　１１　　　　　（ａ）ｌFig. 1 shows an embodiment of this invention, Fig. 1a is a system diagram, Fig. 1 is a front view showing an example of a photodetector, Fig. 2 is a system diagram showing generation of a defocus signal, FIG. 3 is a front view showing the relationship between the light detection device and the light flux in each case shown in FIG. 2, FIG. 4 is a longitudinal sectional view showing the relationship between the reflected light flux and the light detection device, and FIG. 4 is a cross-sectional view corresponding to FIG. 4, FIG. 6 is a perspective view showing another example of the photodetecting device used in this invention, and FIG. 7 is a block diagram showing another embodiment of this invention. In the figure, 3 is a half mirror, 15 is a condensing lens, 81
82 is a half mirror (second spectroscopic device); 22 is a first photodetector; 23 is a half mirror (first spectroscopic device);
12 is a drive control device, 31 is a differential amplifier, 41 is a slit, and 42 and 43 are compensation devices, respectively. Note that the same reference numerals in each figure indicate the same or corresponding parts. l ql 4th eye 5th eye 1 1,. 6th 31 11 (a) l

Claims

[Scope of utility model registration request]

(1) A light beam is projected onto a record carrier on which information is optically recorded via a rotatable deflection mirror, and the reflected light beam is projected onto a photoelectric conversion device via the deflection mirror and converted into an electrical signal. In an optical information reproducing device for reproducing the information, a first spectroscopic device that spectrally spectrally part of the reflected light beam projected onto the photoelectric conversion device as a position error detection light beam; a second spectroscopy device that separates the separated light beam for position error detection into a first light beam and a second light beam; a first photodetector having a rectangular light-receiving surface disposed apart by a deviation distance of 1, the longitudinal direction of which is parallel to the direction of movement of the optical path of the first light beam due to rotation of the deflection mirror; A predetermined second beam is placed behind the second light beam condensing point from this condensing point.
a second photodetector having a rectangular light-receiving surface arranged at a distance of a deviation distance of and whose longitudinal direction is parallel to the direction of movement of the optical path of the second light beam due to rotation of the deflection mirror; Feedback control of the relative position between the record carrier and an optical system device that projects the light beam onto the record carrier by a signal of the difference between the output of the first photodetector and the output of the second photodetector. An optical information reproducing device comprising a drive control device.

(2) The optical information reproducing device according to claim 1, wherein the first shift distance and the second shift distance are equal to each other.

(3) The first deviation distance and the second deviation distance are different from each other, and the difference between the outputs of the first light detection device and the second light detection device occurs due to the difference in these deviation distances. The optical information reproducing apparatus according to claim 1, further comprising a compensation device for compensating for.

(4) The first shift distance and the second shift distance are different from each other, and the difference in these shift distances causes sensitivity in the first light detection device and the second light detection device. The optical information reproducing device according to claim 1, wherein the difference is compensated for by the light-receiving area of each photodetector.

(5) Both the first photodetecting device and the second photodetecting device are characterized in that the photodetectors are arranged at intervals behind an opaque material having a strip-shaped cut of a constant width. An optical information reproducing device according to claim 1 of the utility model registration claim.

(6) Registration of a utility model characterized in that both the first photodetecting device and the second photodetecting device have an opaque material having a strip-shaped cut of a constant width disposed on the light-receiving surface of the photodetector. An optical information reproducing device according to claim 1.