| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize stable focus servo and tracking servo in an information recording medium having a plurality of recording regions of different track pitches and groove shapes. <P>SOLUTION: A recording track formed by a convex/concave pattern includes first and second recording regions R1 and R2 and a recording region transition section Sx arranged between the first and the second recording regions R1 and R2. The first recording region R1 has a track pitch tp1, a groove width w1, and a groove depth d1 and the second recording region R2 has a track pitch tp2, a groove width w2, and a groove depth d2. These track pitches, the groove widths, and the groove depths satisfy prescribed expressions. The recording region transition section Sx includes a track pitch transition section where the track pitch changes from tp1 to tp2 and a groove shape transition section where the groove width changes from w1 to w2 and/or the groove depth changes from d1 to d2. The track pitch transition section and the groove shape transition section share at least a partial region. <P>COPYRIGHT: (C)2009,JPO&INPIT |
