| 摘要 |
PURPOSE:To provide a mold wherein a magnetic disk composing hub, a hub base material, and an optical disk substrate are simultaneously integrally molded, and a manufacturing method for the optical disk by using the mold. CONSTITUTION:In a mold for manufacturing an optical disk, tionary mold is composed of (1) a sprue bush forming a nozzl touch part, a sprue part, and a center gate part; (2) a stamper forming an information recording surface of the optical disk by being interconnected to the center gate part; and a mirror surface holding the stamper. A movable mold is provided as follows; (a) the mirror surface composing a cavity part together with the stationary mold is provided; (b) a space is provided wherein a recess part in which a center hole of a magnetic disk of a hub is fitted to a tip of an ejectior piston existing at the center of the mirror surface and a tip of a gate cutting pin fits onto a front surface of the disk is provided, and a telescopic cut composed of the same diameter part as that of the magnetic disk and a different levelled small diameter part is fitted in normal contact to the magnetic disk; and (c) the gate cutting pin which passes through a center of th ejector piston, has the same diameter as that of the hub center hole, and can be freely slid in front and in rear, is provided. |
