| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical recording medium capable of having a high recording capacity. SOLUTION: The optical recording medium is formed with a supporting body which consists of a thermoplastic resin and which is 0.3-1.2 mm thick, with a guiding groove 202 on the supporting body, and with at least a reflection film 203, a phase change type recording film 204, and a 3-177 μm thick light transmitting layer 205 successively on the guiding groove 202; assuming that the irregularity of thickness in the light transmitting layer 205 is Δt, the medium satisfies the following relation between the N.A. (numerical aperture) of a reproducing or recording/reproducing optical system and a wave length λ, namely, Δt<=±5.26(λ/N.A.<4> ) (μm). |
