Patent ID: 6142761
Filing Date: 2000-11-07
Classification: B29C,Y10S

Abstract:
An optical disc molding apparatus comprising:a pair of dies movable side in a relative fashion;a pair of metal molds for forming a cavity therebetween;a stamper for transferring an information pit on a disc; anda ring attached to said metal molds, having a holding surface for holding said stamper, said holding surface having a plurality of grooves and holding an outer peripheral surface of said stamper with convex surfaces of said grooves and molding an outer peripheral surface of said disc;wherein said ring is urged against an inner diameter surface of a metal mold to which an outer diameter surface of said ring is attached in such a manner that said ring and said inner diameter surface have no clearance produced therebetween;wherein one of said dies has on its one inner peripheral surface formed concave and convex portions, said ring has on its outer peripheral surface formed concave and convex portions and said ring is attached to said die and said metal mold by engaging said concave and convex portions with each other.