| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical recording medium consisting of an optical disk which is capable of making its storage capacity to >=8 GB and has a ROM(Read.Only.Memory) in at least part as basic constitution. SOLUTION: A light transparent layer 12 is formed on an information recording surface 11 formed with information recording pits and is irradiated with the laser beam of 380 nm<=λ<=450 nm in wavelength λ through a lens system of >=0.76 in N.A(numerical aperture) from the light transparent layer side, by which the reading out of the information is executed. The thickness (t) of the light transparent layer is specified 3 to 182 μm and the thickness unevenness Δt thereof to within ±5.26 λ/(N.A)4 in the region of a signal information section. The track pitch TP on the information recording surface 11 is specified to 0.27 to 0.404 μm, the shortest pit length Pmin of information recording pits to 0.13 to 0.219 μm, the recording linear density LD to a bit string of >=0.146 μm/bit and the depth D of the information recording pits to 0.14 to 0.219 nm. |
