| 摘要 |
PROBLEM TO BE SOLVED: To reduce track offset and to efficiently arrange address information by arranging pre-pits on a virtual extension line of a border part of a groove part and a land part, and arranging pre-pits so as to position at both sides of left and right for the virtual extending line of a groove part center line and a land part center line so as not to exist simultaneously at the both side of the same place of a groove part and a land part. SOLUTION: A groove part 84 and a land part 85 are alternately arranged, and a recording mark 81 is recorded in both regions. A groove is not formed in a pri-pitpart 83, pre-pits 82 are arranged on an extension line of a border of the land part 85 and the groove part 84, the pre-pits 82 are arranged at the upper side for a center line of the land part 85 in a first pre-pit part 831, and the pre-pits 82 are arranged at the lower side for a center line of the land part 85 in a second pre-pit part 832. As when a light spot 21 scans on the land 85, only either of pits is always reproduced, there is no rear that crosstalk from an adjacent track is caused. |
