SUBSTRATE FOR OPTICAL DISK AND METHOD FOR INSPECTING METAL MOLD OF SUBSTRATE FOR THIS OPTICAL DISK

摘要

PURPOSE:To provide a substrate for an optical disk which is accurately formed with rugged information by a stamper, etc. CONSTITUTION:The eccentricity L between a circumferential parting line 30 formed on the stationary mold side of the substrate 1 for the optical disk formed by injecting a molding material into the cavity between the stationary mold and a moving mold and respective central points 32, 33 of a parting line 31 formed on the moving mold side is confined to <=30mum. The small eccentricity L indicates that the misalignment of the centers between the respective molds is small and eventually the high-quality substrate 1 for the optical disk formed with the rugged information by the stamper with high accuracy is obtd.