| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-density optical disk having a structure to prevent the collision of the objective lens of an optical pickup with the high-density optical disk and simultaneously to permit the identification of the uninsertion of the disk even if the objective lens of the optical pickup is perpendicularly moved to the max, moving range on the recording layer of the high-density optical disk in case where the high-density optical disk, like a high-density DVD, is erroneously and backwardly inserted into an optical disk device. SOLUTION: In this high-density optical disk, a projecting part which projects from the disk surface in its clamping region is formed on the side opposite to the surface provided with at least the recording layer. |
