摘要 |
An optical disk having an increased data storage capacity and accessible randomly, the positional shift of which can be quickly detected. An optical disk access device and access method are also disclosed. The optical disk (1) has a track (T1) constructed of two kinds of the first sector (S1) having an ID portion (12) and succeeding sectors (S2) having only a sector mark portion (13), and sector marks of the tracks are different from one another. The data area is increased by compressing the ID portion, and the different marks of the tracks enable quick detection of access positional shift. <IMAGE> |