Abstract: A permanent magnet used in conjunction with electron beam correction is disclosed which is disk-shaped and exhibits in the plane of the disk an asymmetric quadrapole magnetic field. The strength of the magnetic field between any two adjacent poles is proportional to the distance between the two poles giving four magnetic fields of differing strength in view of the differing distances between the four magnetic poles around the periphery of the disk. A plurality of such magnets can be supported adjacent the envelope of a cathode ray tube to achieve electron beam centering, multiple beam convergence, and the like.

Abstract: A magnetic compensation device is disclosed for use with a cathode ray tube which includes a strip having a plurality of holes distributed linearly along the strip. A plurality of fasteners, each fastener comprising a base and a shaft substantially perpendicular to the base, passes through a selected one of the holes in the supporting strip. At least one of the fasteners engages two holes in opposite ends of the strip to hold the strip in a hoop shape. The strip is adhesively secured to a deflection yoke. A plurality of ring-shaped magnets are provided with one such magnet being received on the shaft of selected fasteners. The washer-shaped permanent magnets are positioned about the deflection yoke at equal angles with the axis of rotation of the magnets lying in planes transverse to the central axis of the cathode ray tube.