OPTICAL DISK DEVICE, AND DRIVING CONTROL METHOD OF OPTICAL DISK

摘要

PROBLEM TO BE SOLVED: To reduce track error offset caused by variation of layer thickness of optical disks by digital processing without adopting a special optical system configuration. SOLUTION: This optical disk device includes a signal processing part which generates a track error signal Tr according to Tr=(A-D)-maä(B1+B2)-(C1+C2)} based on differential signals (A-D) showing a difference between respective light receiving element signals A and D of divided light receiving elements, differential signals ä(B1+B2)-(C1+C2)} showing a difference of respective sum signals of C1 and C2, and a coefficient ma set based on a ratio of tilt of DC offset in accordance with lens shift for a predetermined direction. The signal processing part sets the coefficient ma based on a radial position of the recording medium when recording or reproducing is performed for a predetermined recording layer of the optical recording medium. COPYRIGHT: (C)2009,JPO&INPIT