Abstract: Display tube including a convergence correction device which comprises a plurality of correction coils having coplanar axes and being arranged around the tube neck. The coils are of the planar type. More specifically, there are two sets of four coils for generating two differently oriented four-pole fields and two sets of six coils for generating two differently oriented six-pole fields, while all these coils are arranged on one flexible support which is wound around the tube neck a number of times, for example, one set of coils for each turn.

Abstract: A deflection unit comprising a set of preformed diametrical deflection coils. A hollow coil support of synethic material includes at least two lugs into which respective permanent deformations are impressed. The coils are mechanically anchored to the lugs by means of, for example, an ultrasonic welding process in which the locations of the coil support situated opposite supported locations of the coils are softened and pressed into the coils. The coils substantially free of the coil support, i.e., the larger part of each coil is free of the coil support, and are not deformed so that their mutual position is accurately maintained.

Abstract: Deflection unit mounted around a display tube for deflecting electron beams across the display screen includes a line deflection coil and a field deflection coil. A compensation coil system for generating a magnetic compensation field oppositely directed to the line frequency radiation field in a space in front of the display screen includes core means of a magnetizable material positioned between the display screen and the deflection unit in a plane parallel to the display screen and two diametrically arranged coils each having at least one turn.