| 摘要 |
PROBLEM TO BE SOLVED: To provide a wobble signal demodulating method, in which a wobble signal obtained based on reflected light from a recording surface of an optical disk is accurately demodulated. SOLUTION: A frequency component that exceeds at least 1/5 of fundamental frequency of a wobble signal Swb is extracted from the wobble signal, and phase demodulation for a phase-demodulated-wave section is performed, based on the frequency component and a clock signal generated by a carrier-wave section. Accordingly, even if low-frequency noise contained in the wobble signal is eliminated, since the frequency components exceeding at least 1/5 of the fundamental frequency remain unchanged in a signal to be phase-demodulated, deterioration of a signal in the phase-demodulated wave section can be suppressed. Thus, a changed position of the phase in the phase-demodulated wave section can be recognized accurately, and as a result, the wobble signal can be accurately demodulated. COPYRIGHT: (C)2005,JPO&NCIPI
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