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:
Jun. 18, 2002
Filed:
Sep. 27, 1999
Hitachi, Ltd., Tokyo, JP;
Abstract
A cathode-ray tube that has an electron gun including a final-stage main lens made up of a last accelerating electrode and a focusing electrode and having a focus action stronger in horizontal direction than in vertical direction, an electron lens of a first kind formed between the divided focus electrodes and having a focus action stronger in the vertical direction than the horizontal direction to vary the cross sectional shape of an electron beam with an increase of the deflection amount, an electron lens of a second kind formed between the divided focus electrodes for weakening the lens strength with an increase of the deflection amount of an electron beam, and an electron lens of a third kind made up of at least one electrode constituting a three electrode section and having a focus action stronger in the horizontal direction than in the vertical direction. The dynamic focus voltage which decreases with an increasing deflection amount is reduced. The horizontal diameter of an electron beam spot is reduced on the central area of the screen.