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:
Aug. 31, 1993
Filed:
Jan. 30, 1991
Applicant:
Inventors:
Masayoshi Misono, Chiba, JP;
Satoru Miyamoto, Mobara, JP;
Kiyoshi Nakamura, Mobara, JP;
Masahiro Miyazaki, Mobara, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G09G / ; H01J / ; H01J / ; H01J / ;
U.S. Cl.
CPC ...
315382 ; 313414 ; 315 15 ;
Abstract
An electron gun in which at least two of a plurality of electrodes constituting the electron gun are endowed with structures for generating rotationally-asymmetric electric fields, in electron-beam apertures of the electrodes or around the electron-beam apertures, and a cathode-ray tube which comprises the electron gun can enhance focus characteristics and attain favorable resolutions over the whole area of a screen and in all the current ranges of electron beams, and they do not give rise to moire in the small current range of the electron beams, without supplying a dynamic focus voltage.