| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that it takes time to access an optical disk where information layers of a plurality of different optical disk specifications are laminated in one disk, when the optical disk is read/written by a compatible optical disk device coping with the plurality of optical disk specifications, because a type of one information layer not recorded in another information layer.SOLUTION: A management area of a BD layer includes information showing presence or absence of each of a plurality of types of other information layers different from the BD layer in recording density. The BD layer having the management area provided therein has recording density higher than that of any other information layer, and the management area includes information showing which of a read only type, a write once type, and a rewritable type the information layer is, in the case of the presence of the other information layers. |
