| 摘要 |
PURPOSE:To execute an access control of a track counting system by constituting the title optical disk to record the same data in data of a phase bit, at a roughly equal interval in one round of a track, and data of the remaining four bytes is recorded by a laser beam. CONSTITUTION:A track address data part 7 is provided in a track 1, and has length of 4.5 bytes in the same way as a segment part 2. Its internal structure has a gap part 4 and a data part 3, but all are recorded by a pre-bit, and in the data part 3, a code corresponding to an address of a track is recorded. Accordingly, all address parts 7 record the same code in some track. In such a way, in case of executing an access control of a track counting system, a position of an optical head can be derived by looking at the address part 7. In this regard, wobble pits 5, 8 are shifted by about 1/4 of a size of the pit to the left direction from the track center, when they are looked at from the advance direction of a light beam, and a wobble pit 6 is shifted by about 1/4 to the right direction. |
