| 摘要 |
PROBLEM TO BE SOLVED: To improve both erase rate and C/N of a phase change type optical disk which performs recording on the land and groove. SOLUTION: At least a 1st dielectric layer 2, a phase change recording layer 3 which has the reversible change of phase between the crystalline and amorphous substances by irradiation of a laser beam, a 2nd dielectric layer 4, a reflecting layer 5 and a protective film 6 are successively laminated on a light transmitting substrate 1. Then the information is recorded between the guide grooves which are formed on the substrate 1. In such a constitution of a phase change type optical disk, a ratio between the groove width and land width is set at about 45:55. Thus, both erase rate and C/N between groove recording and land recording are approximately equal and the erase rate is particularly improved in the land recording. |
