OPTICAL DISK AND SURFACE TREATMENT THEREOF

摘要

PURPOSE:To suppress the adhesion of dust as far as possible and to improve the reliability of the optical disk in recording, reproducing and erasing by uniformly forming at least antistatic layers corresponding to the effective recording region of the optical disk and providing electric conductivity over the entire surface of a substrate including a center hub. CONSTITUTION:A large recessed part 7 which serves as a liquid pool for a liquid antistatic agent to be applied by a spin coating method is formed in an annular shape in the radial position corresponding to the joint of metallic molds for injection molding on the polycarbonate substrate 1 formed by injection molding. The rotating speed of the optical disk is increased at the time of first forming the antistatic layer 2a in the region on the outer side of the large recessed part 7 and the rotating speed of the optical disk is lowered at the time of forming the antistatic layer 2b afterward. The antistatic layer 4 is formed on the front surface of the center hub 3 as well.