OPTICAL DISK DEVICE AND CONTROL METHOD OF OPTICAL DISK DEVICE

摘要

<P>PROBLEM TO BE SOLVED: To provide an optical disk device exactly detecting a defect even when an SN (Signal to Noise) ratio of a signal included in light reflected from an optical disk is not satisfactory and to provide a control method of the optical disk device. Ž<P>SOLUTION: The optical disk device 10 includes: a push-pull signal generating part 20 generating a push-pull signal based on light reflected from a recording type optical disk 1; an automatic gain control part 26 generating a signal having an amplitude of a prescribed magnitude by extracting a wobble signal having a frequency corresponding to a wobble of a pregroove of the recording type optical disk 1 from the push-pull signal and amplifying the wobble signal according to the amplitude of the extracted wobble signal; and a protection signal output part 40 monitoring the amplification factor of the wobble signal by the automatic gain control part 26 and determining that there is a defect on the recording type optical disk 1 when a change in the amplification factor is larger than a prescribed magnitude. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž