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. 12, 1988
Filed:
Feb. 05, 1986
Shigehiko Yamamoto, Tokorozawa, JP;
Sadanori Taguchi, Nishitama, JP;
Toshiyuki Aida, Chofu, JP;
Isato Watanabe, Hachioji, JP;
Susumu Kawase, Higashimurayama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The present invention relates to an impregnated cathode produced by attaching at least two layered thin films, the thin films comprising an under layer consisting of a high melting point metal thin film composed of, for example, Os, Ru, Rh, Pd, Ir, Pt, Re, Mo, W, Ta, etc., and an over layer consisting of a high melting point metal layer which contains Sc.sub.2 O.sub.3 and which is placed over the layer, on the surface of the impregnated cathode pellet generated by impregnating a refractory porous base body with electron emissive materials. The invention relates also to an electron tube having this cathode. This cathode maintains a low work functional mono-layer stably for a long period of time on its surface.