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. 25, 2003
Filed:
Aug. 22, 2001
Applicant:
Inventors:
Assignee:
Kabushiki Kaisha Toshiba, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J 2/950 ; H01J 1/20 ; H01J 2/904 ;
U.S. Cl.
CPC ...
H01J 2/950 ; H01J 1/20 ; H01J 2/904 ;
Abstract
The electron beam generating section in an electron gun assembly includes a cathode having an electron emitting surface. The surface of the cathode is divided into at least three regions of first, second and third regions which have different electron emission capabilities. The first region is arranged in the center of the surface of the cathode. The second region has its portions arranged on opposite sides of the first region in the horizontal direction. The third region has its portions arranged on opposite sides of the first region in the vertical direction.