INJECTION MOLDING MOLD FOR OPTICAL DISC SUBSTRATE, AND MANUFACTURE OF OPTICAL DISC SUBSTRATE USING THE MOLD

摘要

PURPOSE: To 'eliminate the gradation of the eccentricity between the center hole and groove of a molded optical disc by a method wherein the outer diameter of an inner circumference stamper holding member at a room temperature is practically enlarged in accordance with the temperature of the mirror surface plate of a molding mold. ;CONSTITUTION: A center hole 16 is provided in a fixed side mirror surface plate 4 having a stamper 7 and an inner circumference stamper holding member 10 by which the inner circumference of the stamper 7 is retained is aligned with the center hole 16. The inner circumference stamper holding member 10 and the fixed side mirror surface plate 4 are aligned with each other by taper alignment and, further, the diameter of the tapered tip of the inner circumference stamper holding member 10 is made to be relatively larger than the inner diameter of the tapered rear end 18 of the center hole 16 of the fixed side mirror surface plate 4 in accordance with a temperature at which the temperature of the molding mold is controlled. With this constitution, the degradation of the eccentricity between the center hole 16 and groove of the molded optical disc substrate can be improved.;COPYRIGHT: (C)1996,JPO