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. 05, 1991
Filed:
May. 22, 1990
Loren L Maninger, Lancaster, PA (US);
Frank M Koch, Lancaster, PA (US);
RCA Licensing Corporation, Princeton, NJ (US);
Abstract
The present invention provides an improvement in a color display system. The system includes a cathode-ray tube having an electron gun for generating and directing three electron beams along paths toward a screen of the tube. The gun includes electrodes comprising a beam forming region, electrodes for forming a prefocus lens and electrodes for forming a main focusing lens. The system also includes a magnetic field deflection yoke. The improvement comprises means for applying a dynamic signal to one of the electrodes forming the prefocus lens when electron beam current drops below a predetermined level. The dynamic signal is a maximum voltage when there is no deflection of the electron beams and decreases in voltage to a minimum at maximum horizontal deflection of the electron beams.