Vertical coil for a deflection yoke

Abstract

A vertical coil for a deflection yoke designed for use with a tri-gun in-line cathode ray tube includes a core comprising a semi-circular split core part and a winding formed of continuous wire turns on the core part. The winding comprises first and second sections and one or more crossover turns connecting the sections. The sections are circumferentially spaced from each other along the core part with the crossover turns extending therebetween on the outer surface of the core. The sections define an area on the inner surface of the core extending from the interior to the exterior edge thereof which is substantially devoid of crossover turns. This configuration serves to generate a magnetic field which converges the beams along the vertical center axis of the tube screen without additional circuitry, auxiliary windings or other means to achieve this result.

What is claimed is: 
     
       1. A deflection yoke coil of the type for use with a tri-gun in-line cathode ray tube, said yoke coil comprising a core and a winding formed of continuous wire turns, said winding comprising first and second sections and .[.one or.]. more .Iadd.than one .Iaddend.crossover turn.[.s.]. connecting said sections, said sections being spaced from each other along said core with said crossover turns extending therebetween on the outer surface of said core, said sections defining an area on the inner surface of said core extending from the interior to the exterior edge of said core which is substantially devoid of crossover turns. 
     
     
       2. The yoke coil of claim 1 wherein the width of said area at the smallest point is substantially larger than the wire diameter of a turn. 
     
     
       3. The yoke coil of claim 1 wherein said core is outwardly flared and wherein said area follows the contours of the inner surface of the core. 
     
     
       4. The yoke coil of claim 3 wherein the width of said area increases in accordance with the outward flare of the core. 
     
     
       5. The yoke coil of claim 1 wherein said core comprises a pair of semi-circular split core parts, said first and said second winding sections being situated on the same core part. 
     
     
       6. The yoke coil of claim 5 wherein said area is located substantially at the central portion thereof. 
     
     
       7. The winding of claim 1 wherein lines drawn parallel to the sides of said area converge at a point spaced from the interior edge of the core. 
     
     
       8. The yoke coil of claim 5 wherein said sections are circumferentially spaced along said core part.