PHASE CHANGE TYPE OPTICAL RECORDING MEDIUM AND RECORDING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a phase change type optical recording medium capable of suppressing cross-erase and variations in the area modulation rate of a multi-value recording mark, using a conventional DDPR (Data Detection using Pattern Recognition) multi-value judgment technique for enabling high-density recording as compared with before, and performing multi-value recording by an area modulation system, and to provide a recording method thereof.

SOLUTION: The phase change type optical recording medium is an optical recording medium, where one recording mark is formed in each recording region formed by dividing into equal area and multi-value recording can be made. In the phase change type optical recording medium, there are at least provided: a first protective layer; a transparent heat conduction layer; a second protective layer; a recording layer with Sb and Te as main constituents; a third protective layer; and a reflection layer from the incidence side of recording/reproduction laser beam on a substrate. In this case, refractive indexes in recording/reproduction wavelengths λ of the first protective, transparent heat conduction, and second protective layers are set to be n1, n, and n2, respectively. In the case of n1n>n2, the thickness of the transparent heat conduction layer is λ/4n substantially. Or, in the case of n1n2, or n1>n and nCOPYRIGHT: (C)2005,JPO&NCIPI