| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of track jumping during data recording in an optical disk device such as a CD-R drive. SOLUTION: Wobble components included in return light signals during data recording are extracted in a main beam addition amplifier 30, a sample- and-hold circuit 32 and a band-pass filter 34. The wobble components become almost 0 at the time of being on a track and are outputted as signals for which phases are inverted mutually in the case of being shifted to an inner peripheral side or an outer peripheral side. Wobble signals obtained by reproducing power and the wobble components are added in an addition amplifier 36 and a CPU 38 judges to which one of the inner peripheral side and the outer peripheral side de-tracking occurs from the amplitude of added signals and adjusts a tracking offset.
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