Patent ID: 8582412

Claim:
An optical information recording medium, comprising: a substrate, at least two information recording layers, and a light-transmitting layer, the at least two information recording layers 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, a thickness tolerance of the light-transmitting layer being greater than 2 μm but not greater than 3 μm, 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.