| 摘要 |
PROBLEM TO BE SOLVED: To prevent a utilization factor of recording surface from decreasing by making an interval, between track centers of a final sector end of an reproduction-dedicated area and a first track of a first sector in a rewritable area 2 to 20 times as wide as a track pitch for a range. SOLUTION: For example, when a track pitch is 0.74μm, if a track interval in the boundary part is made 2 to 20 times the track pitch, a tolerance can be 1.48μm to 14.8μm in length. Namely, a relative position of two beams of an original board cutting device may be 8.14+/-6.66μm and a setting error is permissible up to 6.66μm. Furthermore, for example, when the track pitch is 0.74μm, if the track interval in the boundary part is from 2 to 8 times the track pitch, a tolerance can be 1.48μm to 5.92μm in length. |
