| 摘要 |
PROBLEM TO BE SOLVED: To obtain a substrate for optical disk with which the easy forming of stack ring is possible and cold mark is not generated and its molding method and a metal mold. SOLUTION: The mold for molding the substrate 1 for optical disk having the stack ring 2 is provided with an electric heater 15 as temp. control means on the rear side of the shape of the groove 4 for forming the stack ring 2, by thereby, the solidification of resin surface layer is retarded and the trace of the disturbances formed by the escape of the air included in corner parts is crushed. As a result, the formation of the cold mark is prevented. |
