| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that inter-layer crosstalk is large in an identifying information region or a boundary region between a recorded part and an un-recorded part, in a recording type multi-layer optical disk. SOLUTION: In an optical disk having at least one information recording surface, the optical disk includes at least a plurality of information tracks on the optical recording surface, each track is spiral and consists of a part corresponding to one turn, wherein a plurality of information recording units are disposed on the plurality of tracks, and wherein the fronts of any two information recording units disposed on all tracks positioned within a range of five microns with respect to a radial direction are caused to be at an interval equal to or more than five microns with respect to a circumferential direction. |
