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:
Nov. 17, 1998
Filed:
Jul. 12, 1996
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
313336 ; 3133 / ; 313311 ; 313351 ; 313345 ; 313309 ;
Abstract
A cathode includes a hairpin type filament made of a refractory metal such as W, Mo or Re; a single crystal needle, made of a refractory metal such as W, Mo or Re joined to the filament; and a reservoir formed by applying a slurry of a powder of a metal or metal compound and an organic solvent containing nitrocellulose in the vicinity of a junction between the single crystal needle and the filament. The powder for a reservoir is made of a metal lower than the single crystal needle in a work function or electron affinity, such as Ti, Zr, Hf, Y, Th, Sc or Se, or a compound thereof.