OPTICAL DISK MEDIUM AND OPTICAL DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain an optical disk medium in which information signals can be recorded and reproduced continuously in both of the groove part and land part and to provide an optical disk device which uses the above medium. SOLUTION: The groove part and land part of the optical disk medium are used as information tracks and the groove tracks and land tracks are formed into one spiral track. In the optical disk device, the polarity of the control direction of tracking is inversed between periods when a light spot is on the groove tracks and on the land tracks so that tracking is continuously carried out on both of the groove tracks and land tracks to continue recording or playing back.