Patent ID: 8189444

Claim:
An optical information recording medium, comprising: a substrate; an information recording layer; and a light-transmitting layer, the information recording layer and the light-transmitting layer being stacked on the substrate, said optical information recording medium being reproduced by use of reproducing light, having a wavelength of not less than 400 nm but not more than 410 nm, via an objective lens having a numerical aperture of not less than 0.84 but not more than 0.86, information being recorded on the information recording layer as marks and spaces coded by RLL(1,7) modulation, each of the marks and spaces having one of a plurality of lengths, and 2T marks and 2T spaces of the marks and spaces being formed to be shorter than 0.12 μm, and the information recording layer being a layer allowing a reproduction signal waveform, obtained by the reproducing light of a power of not less than 0.8 mW, to be reproduced in accordance with a PR(12221)ML decoding method.