Title:
OPTICAL DISK INFORMATION RECORDING AND REPRODUCING DEVICE
Document Type and Number:
Japanese Patent JP3272003
Kind Code:
B2
Abstract:
PURPOSE: To provide the optical disk information recording and reproducing device equipped with an automatic gain control means capable of keeping the prescribed peak value while absorbing the dispersion of an information reproduction signal detected by an optical head and having ample frequency characteristic so as to amplify the high frequency component without distortion.
CONSTITUTION: The gain is controlled by a first voltage control amplifier (13a) which is controlled by an open loop and a second voltage control amplifier (13b) which is controlled by a closed loop, thereby keeping the peak value of the information reproduction signal to be sent from a preamplifier (12). The variable width of the gain of the first voltage control amplifier (13a) is taken wider than that of the second voltage control amplifier (13b). The gain of the first voltage control amplifier (13a) is fixed to the prescribed value, and the gain of the second voltage control amplifier (13b) is automatically controlled by a closed loop with the second voltage control amplifier (13b) arranged at the post stage.
Inventors:
Toyoaki Takeuchi
Application Number:
JP28298091A
Publication Date:
April 08, 2002
Filing Date:
October 29, 1991
Export Citation:
Assignee:
Olympus Optical Co., Ltd.
International Classes:
G11B7/00; G11B7/005; G11B20/04; G11B20/10; (IPC1-7): G11B7/005; G11B20/04
Attorney, Agent or Firm:
Sugimura Kosaku (1 person outside)
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