发明授权
- 专利标题: Servo circuit for a signal reproducing apparatus
- 专利标题(中): 用于信号再现装置的伺服电路
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申请号: US499245申请日: 1983-05-31
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公开(公告)号: US4580255A公开(公告)日: 1986-04-01
- 发明人: Shigeki Inoue , Takao Arai , Yukio Fukui , Takashi Takeuchi , Harushige Nakagaki , Masafumi Nakamura , Tatsuo Baba
- 申请人: Shigeki Inoue , Takao Arai , Yukio Fukui , Takashi Takeuchi , Harushige Nakagaki , Masafumi Nakamura , Tatsuo Baba
- 申请人地址: JPX Tokyo
- 专利权人: Hitachi, Ltd.
- 当前专利权人: Hitachi, Ltd.
- 当前专利权人地址: JPX Tokyo
- 优先权: JPX57-91251 19820531; JPX57-94812 19820604; JPX57-94808 19820604; JPX57-125634 19820721; JPX57-149313 19820830; JPX57-197468 19821112
- 主分类号: G11B7/09
- IPC分类号: G11B7/09 ; G11B19/04 ; G11B20/10 ; G11B21/10 ; G11B7/00
摘要:
A servo circuit for a signal reproducing apparatus for reproducing signals from a record medium such as a disc utilizing an optical pickup, wherein a variable gain amplifier is arranged in a servo loop between a pickup and an actuator so that the pickup is caused to track a signal track in accordance with a servo error signal produced by the variable gain amplifier. A playback condition of a disc is discriminated by detecting the number of errors in a signal reproduced from a recorded signal on the disc by the pickup, and a gain of the variable gain amplifier is controlled by the discrimination output so that the variation of the servo error signal caused by a difference in reflectance between individual discs is eliminated and a loop gain appropriate to an individual disc is automatically set.