| 摘要 |
PROBLEM TO BE SOLVED: To surely irradiate a boundary area to surely crystallize an optical disk by setting the diameter of an initialization beam spot to the specified value or more of pitch per one rotation of the disk to be initialized when a re-writable optical information recording medium is initialized. SOLUTION: A first dielectric layer is laminated on a transparent substrate, a recording layer is also laminated on the first dielectric layer and further a second dielectric layer is laminated on the recording layer successively. A signal contrast in reproducing is improved and further crystallization of the recording layer is promoted to improve an erasing ratio by the effect protecting the transparent substrate and the recording layer from heating and an optical interference effect such that the first and second dielectric layers prevent the transparent substrate and the recording layer from the deterioration of the recording characteristic deformed by laser beam irradiating heat in recording. And a feed pitch (b) per one rotation of the optical disk in initialization to the diameter (a) of the laser spot beam is set so as to satisfy a>2b, whereby the initialization area on the optical disk is irradiated two times or more by the laser beam and crystallization is uniformly executed. |
