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:
Dec. 26, 2000
Filed:
Jul. 08, 1998
Applicant:
Inventors:
Hsing-Yao Chen, Barrington, IL (US);
Chun-Hsien Yeh, Taipei, TW;
Assignee:
Chunghwa Picture Tubes, Ltd., Taoyuan, TW;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
313414 ; 313409 ; 313412 ; 313449 ; 315 14 ; 315382 ; 3153821 ; 31536815 ;
Abstract
An internal resistor within a color cathode ray tube (CRT) is connected to a voltage source and is coupled across a G4 grid and a G6 grid of the CRT's multi-grid quadrupole (QPF) electron gun. De-coupling the G4 grid from the G2 grid in the electron gun's prefocus lens and operating the G4 grid at a higher voltage as used in the gun's high voltage main focus lens moves the equivalent lens of the prefocus and main focus lenses toward the CRT's display screen and reduces electron beam magnification and spot size for improved video image definition and focusing.