OPTICAL DISK-LIKE RECORDING MEDIUM PLAYBACK DEVICE, AND SIGNAL RECORDING/UNRECORDING JUDGMENT METHOD FOR OPTICAL DISK-LIKE RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To accurately judge whether signal has been recorded in a disk.;SOLUTION: A gain is adjusted so that the peak value of an RFDC signal falls within an optimal range in a state where a disk is rotated at a quasi-normal speed after offset adjustment of the RFDC signal. By comparing a ratio between the peak value Vp and the bottom value Vb of the RFDC signal measured in the gain-adjusted state with a threshold value, whether a signal has been recorded in the disk is judged.;COPYRIGHT: (C)2009,JPO&INPIT