| 摘要 |
PURPOSE:To make a signal characteristic satisfactory, to improve the appearance of an optical disk and to stably form the optical disk with the satisfactory appearance by setting the pit inclined angle of a stamper in a specified range. CONSTITUTION:In the stamper for forming the optical disk used exclusively for reading a pit signal, an inclined angle theta of a pit part of the stamper corresponding to the pit of the optical disk is set to 5-22 deg.. Here, the inclined angle of the pit part is the angle theta formed by a base surface 1 (or a deep surface 2) and a pit wall 3. When the inclined angle is <15 deg., the quality of a sound is degrated in a picture and when the angle is >=23 deg. and the disk is detached from the stamper, the pit deformation of the disk is generated. Thus, the stamper can be obtained so as to obtain the optical disk for which there is no pit deformation and signal (picture, sound) degradation. |
