MOLDING DIE FOR GLASS LENS

摘要

PROBLEM TO BE SOLVED: To improve the durability of a molding die and the yield of a product (lens) by preventing a work (glass) from stacking to the molding die of a glass lens and preventing the molding face of the die from being damaged for a long time. SOLUTION: A transparent carbon film 2 having >=95 at.% carbon content and 3,000 to 7,000 Knoop hardness is formed on the surface of the die base material 1. The transparent carbon film 2 contains no hydrogen, has a small content of a graphite component and has a long life.