OPTICAL DISK MEDIUM AND OPTICAL DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To reproduce data with high reliability by optimizing learning of a radial tilt position of an optical head. SOLUTION: This optical disk device has a jitter quantity measuring means 41 for detecting a jitter quantity from a regenerative signal, a radial tilt position varying means 43 for changing the radial tilt position of the optical head, a radial tilt position learning means 42 for deciding the radial tilt position where the jitter quantity is minimized from the output signal of the jitter quantity measuring means 41 in the different radial tilt positions and sets the radial tilt in the optimum position.