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. 01, 2001
Filed:
Apr. 01, 1999
Hitachi, Ltd., Tokyo, JP;
Abstract
A color cathode ray tube includes a phosphor screen, cathodes, a G1 electrode, a G2 electrode, a G4 electrode, a G5 electrode and an anode for focusing the electron beams on the phosphor screen. The G5 electrode is divided into plural sub-electrodes arranged to be supplied alternately with a first focus voltage and a second focus voltage, at least one electrostatic quadrupole lens is formed between two of the sub-electrodes supplied with the first and second focus voltages, respectively, at least one lens for correcting curvature of the image field is formed between two of the sub-electrodes supplied with the first and second focus voltages, respectively. The G4 electrode, the G5 electrode and the phosphor screen satisfy following inequalities: 0.0625×L (mm)≦B−20A/(3&phgr;)≦22.00 mm, L(mm)≦352 mm, where A (mm) is an axial length of the G4 electrode, &phgr;(mm) is an average of horizontal and vertical diameters of a center electron beam aperture in the G4 electrode, B(mm) is an axial length from a cathode side and to a phosphor screen side end of the G5 electrode, and L(mm) is an axial distance from the phosphor screen side end of the G5 electrode to a center of the phosphor screen.