Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system
Patent
1989-06-21
1992-01-28
Richardson, Robert L.
Dynamic information storage or retrieval
With servo positioning of transducer assembly over track...
Optical servo system
369 4435, 369 4434, 369 53, 369 4428, G11B 700, G11B 2110
Patent
active
050848488
ABSTRACT:
A feedback control apparatus in an optical recording and reproducing device for recording, reproducing and/or erasing data from an optical recording medium projects a light beam emitted from an optical head onto the optical recording medium. The apparatus includes an actuator for controlling the illuminating conditions of the light beam projected onto the optical recording medium, a detection unit for detecting the illuminating conditions of the light beam projected onto the optical recording medium, and a control amplifier for driving the actuator in accordance with a detection signal outputted from the detection unit, thereby controlling the illuminating conditions of the light beam projected onto the recording medium. The apparatus further includes a switching device for selectively switching from a detection signal from the detection unit to a reference signal, or vice versa, and for inputting into the control amplifier, the reference signal having the same signal level as that of a detection signal which is expected to be outputted from the detection unit when the illuminating conditions of the light beam projected onto the recording medium are appropriate. An offset compensation device outputs an offset compensation signal to the control amplifier. The offset compensation signal is set such that a control signal generated in the control amplifier has a predetermined signal level when the reference signal is inputted into the control amplifier. The apparatus prevents a DC offset from being included in the control signal from the control amplifier and reduces the procedures required for adjustment during the manufacturing process without employing expensive parts and devices and the like, thereby lowering the production costs.
REFERENCES:
patent: 4561080 (1985-12-01), Yamazaki et al.
patent: 4641020 (1987-02-01), Iwai et al.
patent: 4677605 (1987-06-01), Abed
patent: 4890272 (1989-12-01), Ando
patent: 4890273 (1989-12-01), Takeuchi et al.
patent: 4918681 (1990-04-01), Ikeda
The English Abstract of Japanese Laid-Open Patent Application No. 61-45421.
The English Abstract of Japanese Laid-Open Patent Application No. 60-157731.
The English Abstract of Japanese Laid-Open Patent Application No. 63-42042.
Deguchi Toshihisa
Kojima Kunio
Nomura Masaru
Numata Tomiyuki
Hindi Nabil
Richardson Robert L.
Sharp Kabushiki Kaisha
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