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:
Nov. 20, 1990
Filed:
Apr. 27, 1990
Enrique Rodriguez-Cavazos, Indianapolis, IN (US);
Nancy D Graves, Indianapolis, IN (US);
Ronald E Fernsler, Indianapolis, IN (US);
RCA Licensing Corporation, Princeton, NJ (US);
Abstract
A circuit provides North-South pincushion correction and gullwing compensation in a raster display of a television apparatus. A correction circuit generates a generally parabolic, horizontal rate correction signal to correct for North-South pincushion distortion. A gullwing compensation circuit is coupled to the correction circuit and forms a feedback path therein for amplitude modifying the correction signal to further correct for gullwing distortion. The gullwing compensation circuit amplitude modifies the generally parabolic signal as a function of itself, achieving an equilibrium condition. A vertical deflection circuit drives a vertical deflection coil with the gullwing compensated correction signal. The correction circuit comprises a ramp waveform generator having a controllable current source generating a constant component of current for pincushion correction and a variable component of current responsive to the feedback signal for gullwing compensation. The variable component of current varies inversely to the feedback signal, which is coupled in the feedback path to the controllable current source through an inverting amplifier. The output of the inverting amplifier modulates the current supply to modify the resulting shape for the parabolic signal to compensate for gullwing distortion by increasing the slope of the parabola on both lateral sides.