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:
Feb. 29, 2000
Filed:
Jun. 02, 1998
Shoji Shirai, Mobara, JP;
Kenichi Watanabe, Isumi-gun, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
To correct a deterioration by a deflection aberration of an electron beam spot at a peripheral portion of an image plane and to promote the resolution, a cathode ray tube is proposed which is composed of an acceleration electrode 32 and a first kind and a second kind of focusing electrode group 311, 313, 312 and 314 which are applied with a first and a second focusing voltage, wherein a first electron lens in which a first focusing force for focusing the electron beam in the horizontal direction is always stronger than a second focusing force for focusing in the vertical direction, and a second electron lens wherein the focusing force for focusing the electron beam in the horizontal direction or in the vertical direction is stronger than the other depending on the relative sizes of a first focusing voltage applied on the first kind of focusing electrode group and a second focusing voltage applied on the second kind of focusing electrode group, are formed among the first kind and the second kind of electrode group, and a dynamic voltage which changes in accordance with a deflection amount of the electron beam is superposed on a constant voltage, in either one of the first and the second focusing voltage.