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:
Apr. 07, 1981
Filed:
Sep. 27, 1978
Toshiyuki Aida, Tokyo, JP;
Sadanori Taguchi, Tokyo, JP;
Isamu Yuito, Ome, JP;
Ushio Kawabe, Hamuramachi, JP;
Shigehiko Yamamoto, Tokorozawa, JP;
Yukio Honda, Fuchu, JP;
Norio Shibata, Honmacki, JP;
Hiroshi Okano, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electron tube cathode in such a structure comprising a Ni-W-Zr alloy (W content: 20-28 wt. %) having a grain size of 4-10 .mu.m as a base metal, a 1,000-2,000 A-thick Pt film provided on the surface of the base metal, and an electron emitting material layer consisting of alkaline earth metal oxide provided on the Pt film has less emission lowering and less peeling of the electron emitting material layer, even if placed in a long time service. The electron tube cathode can be produced according to a method comprising (i) a step of annealing a base metal of Ni-W-Zr alloy (W content: 20-28 wt. %) at 1,000.degree.-1,200.degree. C., (ii) a step of providing a 1,000-2,000 A thick Pt film on the surface of the base metal, and (iii) a step of providing an electron emitting material layer consisting of alkaline earth metal oxide on the Pt film.