OPTICAL INFORMATION RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an optical information recording medium which has a capacity equal to or higher than that of a DVD-ROM and is suitable for recording at 7 to 17 m/s which is the 2 to 5-times reproducing line speed of the DVD-ROM. SOLUTION: 1) The optical information recording medium which is an optical information recording medium having at least a first thin-film layer (protective layer), phase transition optical recording material layer, second thin-film layer (protective layer) and reflection layer on a substrate and capable of performing recording and reproducing by irradiation with a laser beam utilizing a reversible phase transition between the amorphous phase and crystalline phase of the recording material layer and in which the second thin-film layer is composed of a material essentially consisting of a Zr oxide. 2) The optical information recording medium, in which the second thin-film layer is composed of the material essentially consisting of the Zr oxide so as to have the property that the recording layer remains in the crystalline state at a rotating line speed below 16 m/s and the amorphous phase begins to appear within a range from 16 to 20 m/s when the recording medium is rotated at a specified line speed and is irradiated with the laser beam of intensity 8 to 15 times the intensity of reproduction power.