Patent ID: 6882616

Claim:
An optical recording medium on which light condensed by an objective lens having a numerical aperture of 0.85±0.1 and a wavelength of 405±5 nm is focused for recording or playback, said optical recording medium comprising: a substrate formed with a recessed portion and a projecting portion in a surface thereof, an optical recording layer formed on the substrate at the surface that is formed with the recessed portion and the projecting portion and having a topography corresponding to the recessed portion and the projecting portion, and a light transmission type protection layer formed on the optical recording layer; wherein the optical recording medium is configured to be used when light for recording or playback is focused from the protection layer side to the optical recording layer, an underside of the optical recording layer in the recessed portion and a top side of the optical recording layer of the projecting portion is used as a recording area, and the optical recording medium has a distance between a center of one projecting portion and a center of an adjacent projecting portion used as the recording area of 0.32±0.01 μm; or a distance between the center of one recessed portion and the center of an adjacent recessed portion used as the recording area of 0.32±0.01 μm and has a depth of the recessed portion with respect to a projecting portion in the range of 19 to 24 nm.