| 摘要 |
PURPOSE:To obtain a high quality disc substrate without adhering chips by a process wherein, upon manufacturing an optical disc by injection molding, the part of a spool runner is cut-removed before cutting the gate communicating the runner and cavity, and after forming a substrate protecting film is formed, the separation of the runner is carried out through cutting the gate. CONSTITUTION:After molding an optical substrate 7, as a punch 21 is moved up and the upper end of the punch 21 reaches the inner peripheral edge part of a through hole 17 of a fixing side die 12, the part 28a of spool runner spaced apart away from a gate 60 is cut-removed. After that, the disc substrate 7 is taken out through an opening die and a substrate protecting film 30 is formed on the disc substrate 7. Following this, the remaining runner 28b is cut-removed from the disc substrate 7 through gate cutting. Inasmuch as in this manner, the part of the spool runner is cut-removed at the positions spaced apart away from the gate prior to the formation of the disc substrate protecting film, the chips do not adhere the surface of the disc substrate and a high quality molding article is obtained. |
