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:
Sep. 04, 1990
Filed:
Aug. 22, 1989
Applicant:
Inventors:
Masaki Aoki, Minou, JP;
Hideo Torii, Higashiosaka, JP;
Kiyoshi Kuribayashi, Neyagawa, JP;
Hideto Monji, Katano, JP;
Makoto Umetani, Hirakata, JP;
Eiji Fujii, Osaka, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
72462 ; 264107 ; 425810 ;
Abstract
On a cemented carbide alloy disk or a cermet disk having been coated with either an iridium (Ir) alloy film or a ruthenium (Ru) alloy film is formed guide grooves by photography or ECR ion etching. The disk thus obtained is used as an optical or magnetic disk stamper. Next, a glass or aluminium disk is placed between a pair of stampers obtained as above and molded under pressure while heating thereby to make guide grooves of an optical or magnetic disk.