| 摘要 |
PROBLEM TO BE SOLVED: To provide a stuck optical disk capable of identifying more easily and more surely a difference between a currently widespread CD optical disk and its substitute, a DVD optical disk by tactual sensation or the like. SOLUTION: The stuck optical disk (DVD optical disk) is prepared by sticking together two substrates 1, 1 where an information storage area 2 is directed to a sticking side. In an inverted side of the sticking surface of the substrate 1, a recessed and projected part 30 constituting a stack ring is formed in both sides or one side thereof (formed in both sides in FIG. 4). This recessed and projected part 30 is constituted of a combination of a recessed part and a projected part different from the stack ring constituted only of the projected part of the CD optical disk. Thus, the CD optical disk and the DVD disk which is a stuck optical disk are identified. By changing the shape of the recessed and projected part 30, different kind of stuck optical disks is identified. |
