| 摘要 |
PURPOSE:To enable the easy and good formation of a protective film for covering and protecting a signal recording part and to control the double refractive characteristic of a disk substrate in accordance with the molding conditions for the disk substrate. CONSTITUTION:This optical disk is constituted by having the disk substrate 100 which is flattened in the one main surface part formed with the signal recording part over the entire surface thereof and is fed with an annular groove part 101 in the position on the side inner than the signal recording part 103 of the other main surface part. |
