JPS60173131U

JPS60173131U - Optical recording disc playback device

Info

Publication number: JPS60173131U
Application number: JP6089484U
Authority: JP
Inventors: 勇二池戸
Original assignee: パイオニア株式会社
Priority date: 1984-04-25
Filing date: 1984-04-25
Publication date: 1985-11-16

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 the drawing]

第１図はチルトサーボ機構の一例を示す構成図、第２図
はチルトサーボ系の従来例を示すブロック図、第３図は
本考案の一実施例を示すブロック図、第４図は光学式ピ
ックアップの一例を示す断面図、第５図は光学式ピック
アップの可動コイル電流とディスク一対物レンズ間の距
離との関係を示す図、第６図はディスク再生時における
可動コイル電流の変化を示す図、第７図は第３図におけ
るローパスフィルタの出力を示す図、第８図ａ、ｂは第
３図におけるパル長発生手段の出力を示す図、第９図ａ
、　ｂは第３図における２つのサンプルホールド回路の
出力を示す図、第１０図は第３図における比較回路の出
力を示す図である。主要部分の符号の説明、１・・・ディスク、２・・・ス
ピンドルモータ、５・・・対物レンズ、６・・・光学系
ボディ、７・・・チルト機構、３０・・・焦点誤差検出
手段、３１・・田−パスフィルタ、３２・・・パルス発
生手段、３３．３４・・・サンプルホールド回路、３５
・・・比較回路。秦７ｗＪＩ・　　奉８　図（ａ）（ｂ）を朱ｑ図 ↑Fig. 1 is a block diagram showing an example of a tilt servo mechanism, Fig. 2 is a block diagram showing a conventional example of a tilt servo system, Fig. 3 is a block diagram showing an embodiment of the present invention, and Fig. 4 is a block diagram showing an example of an optical pickup. FIG. 5 is a cross-sectional view showing an example. FIG. 5 is a diagram showing the relationship between the moving coil current of the optical pickup and the distance between the disk and the objective lens. FIG. 6 is a diagram showing the change in the moving coil current during disk playback. 7 is a diagram showing the output of the low-pass filter in FIG. 3, FIGS. 8 a and b are diagrams showing the output of the pulse length generating means in FIG. 3, and FIG. 9 a
, b is a diagram showing the outputs of the two sample and hold circuits in FIG. 3, and FIG. 10 is a diagram showing the output of the comparison circuit in FIG. 3. Explanation of symbols of main parts, 1... Disk, 2... Spindle motor, 5... Objective lens, 6... Optical system body, 7... Tilt mechanism, 30... Focus error detection means , 31... field-pass filter, 32... pulse generation means, 33.34... sample hold circuit, 35
...Comparison circuit. Qin 7wJ I・Beng 8 Diagrams (a) and (b) are shown in Zhuq diagram↑

Claims

[Scope of utility model registration request]

(1) Adjustment means for adjusting the inclination of the optical axis of the objective lens in the optical pickup with respect to the information recording surface of the recording disk, and detection for detecting an error in the distance between the information recording surface and the objective lens with respect to a reference distance. 1. A reproducing apparatus for an optical recording disc, comprising: first and second means;
pulse generating means that alternately generates sampling pulses; first and second sample and hold circuits that sample and hold the output of the detection means in response to the first and second sampling pulses; 1. A reproducing apparatus for an optical recording disk, comprising a comparison circuit for detecting a level difference between outputs of a second sample and hold circuit, and wherein the adjusting means performs tilt adjustment according to the output of the comparison circuit.

(2) The optical recording disk reproducing apparatus according to claim 1, wherein the pulse generating means is synchronized with the rotation of the recording disk.