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:
Jan. 30, 1979
Filed:
May. 18, 1977
Applicant:
Inventors:
Masaji Ishii, Tokyo, JP;
Shuzo Watanabe, Kawasaki, JP;
Akira Miyai, Machida, JP;
Hideo Hiraoka, Machida, JP;
Assignee:
Denki Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ; H01J / ;
U.S. Cl.
CPC ...
313336 ; 3133 / ;
Abstract
A thermionic cathode for an electron beam device is provided which comprises a first layer of thermoelectron emissive compound sharpened towards a point, a third layer of metal of high melting point and a second layer of reaction barrier interposed between the first and third layers, current terminals being attached to said third layer. According to the invention, a thermionic cathode capable of emitting stable electron beams of high intensity for a long period of time can be manufactured.