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:
Nov. 21, 1989
Filed:
Oct. 03, 1988
Applicant:
Inventors:
Takashi Yoshioka, Itami, JP;
Akira Doi, Itami, JP;
Assignee:
Sumitomo Electric Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
428698 ; 428699 ;
Abstract
The present invention relates to a die for use in forming optical lenses made of glass or synthetic resin used in OA instruments, VTR, cameras and the like. In order to lengthen the useful life of the die by suppressing the oxidation or deterioration of the die surface due to temperature and atmosphere and reaction of materials of which lenses are made, when lenses are formed, the die is coated with a single-layer or multi-layer thin film of Si.sub.3 N.sub.4 or SiC or compounds thereof, which are superior in wear and corrosion resistance at high temperatures, by the vapor coating method.