| 摘要 |
PROBLEM TO BE SOLVED: To transfer an optical pickup with a proper torque. SOLUTION: A controller 25 acquires a sub-Q code recovered by a digital signal processing circuit 24, and further acquires the information of the present position of the optical pickup 12 on the basis of an absolute time included in the sub-Q code. The controller 25 switches over the gain factor of a servo- gain amplifier provided to a thread servo circuit 18 and the filtering factor of a servo phase compensation filter so that the voltage level of the control voltage applied to a thread motor 26 becomes higher as the position of the optical pickup 12 on an optical disk 1 moves toward the outside. The thread motor 26 rotates with a torque corresponding to the voltage level of the control voltage and moves the optical pickup 12. COPYRIGHT: (C)2004,JPO
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