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. 02, 1986
Filed:
Jul. 01, 1985
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
428336 ; 428472 ; 428701 ;
Abstract
An impregnated cathode comprising a refractory porous body impregnated with an electron emissive material and having an electron emissive surface, and a thin film disposed on the electron emissive surface and composed of a refractory metal and one of Sc, scandium oxide and a mixture thereof. The thin film containing Sc or scandium oxide is generated on the body in subsequent to impregnation of the electron emissive material into the refractory porous body with the result that a mono-atomic layer composed of Ba, Sc and O is maintained on the electron emissive surface over a long period of use.