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:
Oct. 10, 1989
Filed:
Aug. 17, 1987
Masaharu Kumada, Mobara, JP;
Akira Misumi, Mobara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method of producing a shadow mask for use in a color cathode ray tube, has the following steps which are conducted in sequence: preparing an alloy sheet having a composition consisting of 30 to 50 wt % of Ni, 1 to 5 wt % of Ti and the balance substantially Fe and incidental impurities; perforating the alloy sheet by etching; subjecting the etched alloy sheet to a solution heat treatment; forming the alloy sheet after the solution heat treatment into a predetermined form; subjecting the formed alloy sheet to an age-hardening treatment by holding the alloy sheet within a non-oxidizing atmosphere at a temperature ranging between 650.degree. and 750.degree. C.; and subjecting the alloy sheet after the solution heat treatment to a surface blackening treatment thereby forming a black film on the surface of the alloy sheet.