US 4,357,586 AGranted

Color TV display system

AssigneeRCA Corporation

InventorsWilliam H. Barkow, Josef Gross

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Abstract

A self-converging deflection yoke having toroidally-wound vertical deflection coils incorporates a pair of magnetically permeable field formers mounted on either side of the yoke. The field formers shunt a portion of the external field flux to the vicinity of the electron gun assembly where they form a pincushion-shaped field which aids in vertical coma correction. In one embodiment, a yoke comprising planar-wound vertical coils incorporates both coma-correcting rear field formers and a pair of front crossarm assemblies for providing side-pincushion correction. The resultant yoke provides covergence of electron beams free of coma and side-pincushion distortion with reduced sensitivity to transverse motion. In another embodiment, similar results are obtained without the front crossarms by vertical deflection coil having a nonradial winding configuration.

Claims7

Dependent claims

In a television display system having a kinescope including a neck and an electron gun assembly therein for producing three electron beams, and a deflection yoke comprising a deflection coil toroidally wound about a magnetically permeable core encircling the paths of said beams departing said electron gun assembly, said coil producing a delfection field within the region bounded by the interior of said core and an external field;

a magnetic field influencing apparatus comprising:
first and second magnetically permeable members respectively disposed on opposite sides of said yoke, each of said members having a first end disposed within said external field and a second end disposed at the rear of the entrance end of said deflection yoke and adjacent the neck of said kinescope, each of said members channeling a portion of said external field to its second end, each of said second ends being shaped in such manner as to form a pincushion-shaped field within said kinescope neck in the vicinity of said entrance end of said deflection yoke of such a magnitude and extent as to substantially correct coma errors otherwise introduced by said deflection field.

Dependencies are inferred from the claim text.