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:
May. 18, 1993
Filed:
Jun. 07, 1991
Applicant:
Inventors:
Kazunari Noguchi, Chiba, JP;
Syoji Shirai, Mobara, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ; H01J / ;
U.S. Cl.
CPC ...
313414 ; 315 15 ; 315382 ;
Abstract
An electron gun has one first-type electron lens in the focusing electrode which changes the cross-sectional shape of the electron beam into a nonaxisymmetric shape with increase in the degree of the electron beam deflection by applying a first voltage varying in synchronism with deflection, and one second-type axisymmetric electron lens in the focusing electrode which weakens the lens power with increase in the degree of the electron beam deflection by applying a second voltage increasing with the degree of deflection.