| 摘要 |
The optical disc comprises a substrate layer and a data layer disposed on the substrate layer, the data layer having a mark/space data structure arranged in tracks (T1-T6) which are arranged in groups (G1, G2) being separated each by a land section (L). The tracks of the groups (G1, G2) are each arranged as a spiral (S1, S2), and the start (A) of a track (T4) of a consecutive group (G2) begins at a position corresponding with the end (E) of a track (T3) of a preceding group (G1). A group (G1, G2) comprises advantageously an inner track, a center track and an outer track. The optical disc comprises in a preferred embodiment a nonlinear layer with a super-resolution structure and the track pitch (TP) between neighboring tracks (T1, T2) within a group is below the diffraction limit of a corresponding pickup for reading of data. Further, a tracking method is described which does not rely on tracking offsets to detect the inner and outer tracks of a group. |
