| 摘要 |
PURPOSE:To prevent deterioration of an optical recording layer by the effect of heat by forming a track groove part to have the heat conductivity higher than the heat conductivity of a transparent resin substrate. CONSTITUTION:The track groove part 2 of an optical card consisting of the transparent resin substrate 1 having the track groove part 2 on the surface, the optical recording layer 3 provided on the surface of the track groove part 2 and an opaque card base material 5 provided in a manner as to contact the optical recording layer 3 is constituted to have the heat conductivity higher than the heat conductivity of the transparent resin substrate. More specifically, the track groove part 2 is formed by forming the heat conductive thin film having the heat conductivity higher than the heat conductivity of the transparent resin substrate to the thickness corresponding to the depth of the track groove part and subjecting the film to pattern exposing and etching. Since a laser beam used for recording and reproducing information passes the heat conductive pattern part and arrives at the optical recording layer, the heat release characteristic at the time of reproducing the optical recording layer is improved and the degradation in C/N after repetitive reproductions is obviated. |
