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:
Oct. 14, 2003
Filed:
Jun. 01, 2001
Applicant:
Inventors:
Shoji Shirai, Mobara, JP;
Kenichi Watanabe, Isumi-gun, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G09G 1/04 ; H01J 2/950 ;
U.S. Cl.
CPC ...
G09G 1/04 ; H01J 2/950 ;
Abstract
A cathode ray tube is provided having an electron gun equipped with a main lens having a function of controlling a shape of an electron beam spot which is deflected to the peripheral portion of a display screen, to improve a resolution at the peripheral portion of the screen of the cathode ray tube for use in a direct view color television receiver or a color display terminal. To reduce the dynamic correction voltage of the electron gun, an electrostatic quadrupole lens with a simple structure is used, thereby reducing deterioration due to the deflection aberration of the electron beam spot at the peripheral portion of the screen.