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. 01, 1992
Filed:
Jan. 08, 1991
Applicant:
Inventors:
Hiroyuki Teramoto, Amagasaki, JP;
Kimio Hashizume, Amagasaki, JP;
Tetsuya Watanabe, Nagaokakyo, JP;
Hideya Ito, Nagaokakyo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ; C21D / ; C21D / ;
U.S. Cl.
CPC ...
445 47 ; 445 37 ; 148230 ; 148222 ;
Abstract
A method for manufacturing a shadow mask is used for color television picture tubes and the like. The surface of a shadow mask body, made of Fe-Ni type alloy, is ion-nitriding processed so as to make the most of the low thermal expansion property inherent in the alloy. The result is that the color purity degradation caused by the thermal expansion at temperature increases of the mask, and by the resonance of the mask itself, can be prevented, thereby realizing a shadow mask serving to render a highly refined CRT.