Deflection yoke for use in color cathode ray tubes

Abstract

A deflection yoke for color cathode ray tubes, the deflection yoke including a vertical deflection coil for generating a vertical deflecting magnetic field having a barrel-shaped distortion, and a horizontal deflection coil for generating a horizontal deflection magnetic field having a pin-cushion shaped distortion, a differential coil connected to the horizontal deflection coil, a pair of cores located in opposite positions at a smaller rim portion of the yoke, the cores being provided with coils for generating a quadripolar magnetic field, a pick-up coil magnetically coupled to the differential coil or the horizontal deflection coil, and a current waveform shaping circuit for supplying a current to the quadripolar magnetic field generating coils.

What is claimed is: 
     
       1. A deflection yoke for use in color cathode ray tubes, the deflection yoke comprising a larger rim portion and a smaller rim portion, a vertical deflection coil for generating a vertical deflecting magnetic field having a barrel-shaped distortion, and a horizontal deflection coil for generating a horizontal deflection magnetic field having a pin-cushion shaped distortion, a differential coil connected to the horizontal deflection coil, a pair of cores located in opposite positions in relation to the smaller rim portion, the cores being provided with coils for generating a quadripolar magnetic field, a pickup coil magnetically coupled to one of the differential coil and the horizontal deflection coil, and a current waveform shaping circuit for supplying a current to the quadripolar magnetic field generating coils. 
     
     
       2. A deflection yoke according to claim 1, wherein the differential coil is wound around the same bobbin as that for use in the pick-up coil. 
     
     
       3. A deflection yoke according to claim 1, wherein the .[∂]. .Iadd.pick-up .Iaddend.coil is located near .[.windows.]. .Iadd.a window .Iaddend.of the horizontal deflection coil. 
     
     
       4. A deflection yoke according to claim 1, wherein the .[∂]. .Iadd.pick-up .Iaddend.coil is coupled to .[.the respective ends.]. .Iadd.an arched portion .Iaddend.of the horizontal deflection coil. 
     
     
       5. A deflection yoke according to claim 1, wherein the .[∂]. .Iadd.pick-up .Iaddend.coil is provided by part of the horizontal deflection coil. 
     
     
       6. A deflection yoke according to claim 1, wherein each of the pair of cores comprises a ferrite bar shaped like the letter I. 
     
     
       7. A deflection yoke according to claim 1, wherein the each of the pair of cores comprises a ferrite bar shaped like the letter U. 
     
     
       8. A deflection yoke according to claim 1, wherein the correction current comprises a half-cycle of the saw-tooth current. 
     
     
       9. A deflection yoke according to claim 1, wherein the correction current is a parabolic waveform current.