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. 17, 1998
Filed:
Feb. 23, 1996
Michael Denton Grote, Mercerville, NJ (US);
David Sarnoff Research Center, Inc., Princeton, NJ (US);
Abstract
A monochrome cathode ray tube (CRT) yoke includes harmonic windings for correcting spot distortion. In a first embodiment of the invention, the yoke includes harmonic windings in the entrance region of the yoke and harmonic windings in the exit region of the yoke. The harmonic windings in the entrance region produce a barrel-shaped field for correcting spot astigmatism along the diagonals of the CRT. The harmonic windings in the exit region of the yoke produce a pincushion-shaped field for correcting spot elongation along the diagonals of the CRT. In a second embodiment of the invention, the yoke includes harmonic windings only in the entrance region. A stigmator includes quadrupole coils driven at low power vertical scan rates. This allows the stigmator to be positioned near the electron gun and reduces the length of the CRT. In a third embodiment of the invention, the yoke includes harmonic windings only in the exit region.