| 摘要 |
PURPOSE:To measure the amplitude of an wobble pit and evaluate a manufacturing state in the manufacturing process of the disk by providing a group for deflection quantity monitor and a reference group in one part of a master disk. CONSTITUTION:In the area of the master disk besides a user area, a group 10 for deflection quantity monitor and a reference group 9 are provided adjacently in every two tracks. Distances L1-L3 between the center of the group 9 and a group 10, which is formed by modulated laser beam with adding an wobble signal, are measured. Then, a distance corresponding to the amplitude of wobble pits 2 and 3 is calculated and the amplitude of the wobble pits 2 and 3 to a virtual track center line 9' can be calculated. Accordingly, quality can be decided. Thus, the amplitude of the wobble pit can be measured during the process of optical disk manufacture and the quality of the optical disk can be decided. Then, the optical disk with high accuracy can be manufactured. |
