| 摘要 |
PROBLEM TO BE SOLVED: To provide a molding die, for molding an optical glass element at a high temperature, which can be worked into a precise shape and has no cracks. SOLUTION: A cutting layer consisting of a Ni-P vacuum deposition layer is laid on a parent material composed of sintered hard alloys, cermets, ceramics, iron-based alloys and the like. The shape of the optical surface of the cutting layer is finished with a required degree of precision by high-precision cutting using a diamond cutting tool, and thereafter, is heat-treated at a temperature higher than the molding temperature by 10 deg.C or more. Furthermore, an optical glass element having a molding temperature range of 390-490 deg.C is molded by the use of a molding die for optical glass elements, which has a middle layer consisting of nitride or carbide ceramics and the like on the optical surface, which is the molding face, and a mold releasing layer of DLC film (a diamond- type carbon film) on the middle layer. Thereby, an optical glass element, fit for practical use, can be molded by continuous molding.
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