| 摘要 |
PROBLEM TO BE SOLVED: To provide a process step in which the thickness of a resin layer to be formed by a spin coating method is formed in nearly a uniform thickness, which simplified and suppressed in unnecessary waste by devising a method of forming a central hole of a disk-like substrate material. SOLUTION: The method of manufacturing optical disk comprises injecting a synthetic resin from a gate 33 into a cavity of a mold assembly 30 to form the disk-like substrate material 12, solidifying and molding a central part 26 together with a sprue runner 14 in the gate 33, returning the once blanked sprue runner 14 and the central part 26 to the disk-like substrate material 12 so as to be integrated with the disk-like substrate material 12 and forming a recording layer, etc., on the disk-like substrate material 12 formed in the manner described above and further forming a resin layer thereon, then blanking the central part 26 together with the sprue runner 14 to form a central hole 28. |
