| 摘要 |
PURPOSE:To correctly decide a normal/deffective condition by intentionally shifting and forming a projecting part equivalent to a preformat bit in a land part or a groove part within the range of specific % from the central part of the land part or the groove part, and inspecting an area shifted from the center of the projecting part equivalent to the preformat bit by using an optical disk provided with a substrate made by using a stamper placed on the nearly center in the radial direction of disk. CONSTITUTION:The stamper 1 for optical disk provided with a recessed and projection part corresponding to the preformat bit of a tracking groove and an address bit, etc., is provided. At this time, the area intentionally shifting the projecting part equivalent to the preformat bit in the land part or the groove part from the central part of the land part 8 or the groove part 10 within the range of + or -25% of these widths is provided, and the area is placed on the nearly center in the radial direction of disk. By using the optical disk 4 provided with such a stamper 1, signals of the part where the preformat is shifted and the other part are compared and inspected. |
