| 摘要 |
PURPOSE:To execute an access at high speed by providing intrinsic marks at an equal interval on a track, not varying a position of the first pit of a pair of pits and varying a position of the second pit in the track direction. CONSTITUTION:On a disk-like information recording medium 1, a track 2 is formed, and on the track, a sample mark 3 is provided periodically. The sample mark is constituted of two pits which are brought to wobbling in the opposite direction to each other against a virtual track center 2. The first pit 4 exists in a fixed position, and the second pit 5 changes its position little by little in accordance with the track. As for a pattern of the sample mark, there are six patterns in all, and it is repeated periodically at every six tracks. In such a way, since the number of sample marks becomes about three times per one round of the track, the sample period goes to about three times, a position delay by a sampler goes to about one third, and the stability increases further. |
