| 摘要 |
PURPOSE:To obtain the recording medium having a large recording region and the excellent durability of a recording layer by providing pregrooves up on the outer peripheral edge of a disk-shaped substrate having a hole part at the center and having the pregrooves on the surface. CONSTITUTION:The pregrooves 12 and the recording layer 13 are provided on the disk-shaped substrate 11 having the hole part 10 at the center. An inner peripheral side substrate region 14 which is the inner peripheral part on the outer side of the circumferential edge of the hole part 10 and an outer peripheral side substrate region 15 which is the inner part at the outer peripheral edge of the substrate 11 are provided. The pregrooves 12 are formed in the entire region on the outer peripheral side of the region 14 and, therefore, the recording layer 13 can be provided up the desired region in the outer peripheral side direction. The substrate 11 has the ruggedness of the pregrooves 12 over nearly the entire surface and, therefore, the adhesive strength of the recording layer 13 to the substrate 11 is uniformized and increased. The recording medium having the wide recording region and the excellent durability is obtd. in this way. |
