Title:
SERVO-CIRCUIT
Document Type and Number:
Japanese Patent JPS621175
Kind Code:
A
Abstract:
PURPOSE:To reduce the heating of a pickup and to improve the control capacity by detecting the relative mechanical vibration of the pickup to a recording medium and making the gain of a servo-loop high when a level is high and making the gain of the servo-loop low when the level is low, in accordance with the level of its detected mechanical vibration. CONSTITUTION:A vibration detecting circuit 22 is a circuit for outputting a control signal TG for switching the gain to a gain switching circuit 20, detects the level of a relative mechanical vibration between a disk and a pickup from the magnitude of a tracking error signal, sets the gain switching circuit 20 to a high level when its vibration level is higher than a prescribed threshold level, and sets said circuit to a low level when said level is lower than the threshold value. In this way, when the vibration level is high, the good controllability is obtained by a high servo-capacity and when the vibration level is low, the power consumption decreases, the heating of a tracking actuator 18 is reduced, the life of a laser oscillator is extended, and the burden of a power source circuit is reduced.
Inventors:
TAKAO HAJIME
Application Number:
JP13979885A
Publication Date:
January 07, 1987
Filing Date:
June 26, 1985
Export Citation:
Assignee:
NIPPON MUSICAL INSTRUMENTS MFG
International Classes:
G11B21/10; G05B13/00; G05B13/02; G11B7/09; (IPC1-7): G05B13/00; G11B7/09; G11B21/10
Attorney, Agent or Firm:
Toru Sakamoto
Next Patent: BURN-IN TESTING METHOD