The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 15, 1992
Filed:
Oct. 31, 1991
Makoto Umetani, Izumi, JP;
Hideto Monji, Osaka, JP;
Masaaki Sunohara, Nishinomiya, JP;
Jun Murata, Yao, JP;
Toshiaki Takano, Moriguchi, JP;
Yoshinori Shirafuzi, Soraku, JP;
Yoshio Inoue, Katano, JP;
Kiyoshi Kuribayashi, Kitatsuru, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A die for press-molding an optical element with high precision comprises a base material made of a material excellent in heat resistance, heat shock resistance and mechanical strength at high temperature, an intermediate layer formed on the base material and made of a thin film excellent in grinding machinability and cutting machinability, and a surface protective layer formed on the intermediate layer and made of a metal thin film excellent in heat resistance and mechanical strength at high temperature and less reactive to a material of the optical element. Additional thin film may be inserted between the base material and the intermediate layer so as to enhance the adhesion strength between the base material and the intermediate layer. In place of the additional thin film to be inserted, a peripheral flange part of the intermediate layer is removed and thus on the removed peripheral part, the surface protective layer is directly adhered to the base material.