| 摘要 |
PROBLEM TO BE SOLVED: To improve the erasing rate and C/N of a phase change type optical disk for recording on lands and grooves. SOLUTION: A first dielectric layer 2, a phase transition recording layer 3 which causes the phase change between crystal and amorphous phases reversibly by irradiation with a laser beam, a second dielectric layer 4, a reflection layer 5 and a protective film 6 in this order on a light-transmissible substrate 1. Recording is executed in the guide grooves formed on the light-transmissible substrate 1 and between these guide grooves. The ratio of the groove width and land width of this disk is specified to approximately 45:55, thereby, the C/N and erasing rate are made approximately equal between the groove recording and the land recording and particularly the erasing rate in the land recording is improved. |
