| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a stable quality by providing a semipermanent wobbling optical disk which is a wobbling optical disk for performing measurement and adjustment for focus servo characteristics and error correction ability by wobbling an optical disk. <P>SOLUTION: By making a substrate material of glass, excellent mechanical characteristics and a semipermanent optical disk service life are obtained. Also, the size of wobbling is decided from a level difference obtained by recess and projection work and a wobbling value is controlled by glass working accuracy. Also, a glass substrate is provided with wobbling. Further, the thickness of the inner diameter part of the optical disk is reduced, a structure strong against stress at the time of rotation is attained, and sufficient adhesion surface strength is obtained. Also, the wobbling optical disk for CD or for DVD is prepared. <P>COPYRIGHT: (C)2004,JPO |
