| 摘要 |
PROBLEM TO BE SOLVED: To suppress the vibration of an objective of an optical pickup during carrying threads by means of a min. essential lens position servo to enable the stable access operation with a suppressed power consumption. SOLUTION: A band filter 22 is provided between a lens position sensor 12 and a lens position servo circuit 23, the operation software of a system controller 24 is improved to eliminate the duplicated open periods of a first and third on-off switches S1, S3 and that of a second on-off switch S2. The current flowing to a tracking coil is limited to a min. essential period in the thread carrying period, thereby suppressing heating of the tracking coil or adverse influence on an object 4a due to this heating. Doubling of the lens position servo and the tracking servo in the transition of a rough seek operation to a close seek operation is avoided, the vibration of the objective 4a is rapidly damped and the tracking servo is stabilized for a short time.
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