| 摘要 |
PROBLEM TO BE SOLVED: To make data except those in an defective area reproducible by calculating a moving distance of an optical pickup to the inner circumference or outer circumference from the difference between an address pre-stored in a storage part and a predetermined moving destination address of the optical pickup, and retrieving a position presented by the address data from the moved position. SOLUTION: After a focus control circuit 8 applies a triangular wave driving voltage to a focus coil of an optical pickup 6 to lower an object lens, and starts rotating a spindle motor 4, it raises the object lens by applying the driving voltage. Having detected a synchronous signal, a system control part 14 makes a spindle servo system into a closed loop and controls the spindle motor 4 so that a frequency of the extracted rotary synchronous signal matches with that of the reference synchronous signal. An address data extracting circuit 16 extracts the address data while extracting the rotary synchronous signal from an optical disk 2, and an arithmetic calculation part 14b operates calculations to retrieve a target address.
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