GULLWING DISTORTION CORRECTED DEFLECTION CIRCUITRY FOR A SQUARE-PLANAR PICTURE TUBE

摘要

Line and field deflection circuits generate line and field deflection currents in respective line and field deflection windings to scan a raster on the phosphor screen of a square-planar picture tube having an aspherical faceplate. The asphericity of the faceplate subjects the scanned raster to gullwing distortion. A gullwing distortion correction circuit is responsive to signals repeating at line and field rates, respectively, for modulating the field deflection current during a line deflection period within the field deflection trace interval in a manner that corrects gullwing distortion of a corresponding raster scan line.