Patent ID: 7190664

Claim:
An optical disc, comprising an information recording layer having a record of information as a pit train with a predetermined track pitch and a light-transmissive layer formed on said information recording layer so that the information is reproduced by a beam of light illuminated through said light-transmissive layer to said information recording layer by an objective lens, wherein a relationship of 0.194 (λ/NA) 2 ≦TP×Tmin≦0.264 (λ/NA) 2 is satisfied, provided that the track pitch is TP, a pit shortest length is Tmin, a wavelength of the light beam is λ and a numerical aperture of said objective lens is NA, and wherein a pit upper width is 120 nm or smaller in a range of a track pitch of 0.280 to 0.325 μm.