| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve stable focus servo and tracking servo, in an information recording medium having a plurality of recording regions having different track pitches and groove shapes. <P>SOLUTION: In a master exposure device, a recording track formed by an uneven pattern includes first and second recording regions R1 and R2, and a recording region transition section Sx arranged between the regions. A track pitch tp1, a groove width w1 and a groove depth d1 in R1 and a track pitch tp2, a groove width w2 and a groove depth d2 in R2 satisfy expression (1), expression (2) and/or expression (3). Expression (1): 0<¾tp1-tp2¾, expression (2): 0<¾w1-w2¾, and expression (3): 0<¾d1-d2¾. Sx includes a track pitch transition section Stp where the track pitch transits from tp1 to tp2 and a groove-shaped transition section Sg where the groove width transits from w1 to w2, and/or the groove depth transits from d1 to d2, and Stp and Sg share at least a part of a region SL. <P>COPYRIGHT: (C)2013,JPO&INPIT |
