| 摘要 |
PURPOSE:To perform stable sampled servo and, at the same time, to make traverse counting on recording tracks by arranging a traverse information bit, tracking information bit, clock information bit, and focus servo area in the described order from the upstream side of a recording area for control. CONSTITUTION:The recording area ARc for control of each block BL1-BL76 is divided into three areas of pre-format areas AR1 and AR2 and a focus servo area AF. A traverse information bit QT, tracking information bits QW1 and QW and clock information bit QCK are respectively provided on the areas AR1 and AR2. After the area AR2, the mirror surface-like focus servo area AF is provided. Therefore, not only stable servo can be performed even at the switching section from writing scan to reading scan, but also sure traverse counting is performed. |
