| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk or the like capable of easily forming or reproducing a bar code when pirated edition preventing positional information is bar-coaded and recorded in the specific area of the optical disk. SOLUTION: In this optical disk, stripe shaped marks 923a, 923b, 924a, 924b which are long in the radial direction, are formed in a specific annular area not used for recording main information, the width of a mark of sub-information is substantially a half or less of the width T in the circumferential direction of a prescribed partition, and moreover a fixed area of the second recording area is provided with the area wherein the bar code shaped mark is not recorded. |
