| 摘要 |
An optical disk includes groove tracks (270,272) consisting of a plurality of grooves mutually space apart by a fixed space, and land tracks (271,273) consisting of the areas between the groove tracks, wherein the period of wobbling waveforms of the borders (14,15) between the groove tracks and the land tracks are constant on each border, but the wobbling waveforms of the opposite portions of the borders across the track are shifted in phase by a predetermined phase difference. Information is detected by using a predetermined relation between the the information and the changes in said phase shift. <IMAGE> |
