Zenith Electronics Corporation

Zenith Radio Corporation

Fred H Seher

Norman F Gioia

An in-line electron gun in a color TV cathode ray tube generates three coplanar electron beams. The raster pattern projected by the center beam is diminished in vertical height so as to be non-coextensive with the two off-axis beams. The gun is characterized by having two pairs of inwardly converging but non-intersecting magnetic field enhancer means, one of each pair being located at a point of beam egress and embracing in symmetrical relationship one of the off-axis beams. Each member of each of the pairs comprises an L-shaped bracket with the brackets defining an opening therebetween, with one leg of each bracket providing for attachment to the electrode. The brackets, the predetermined angle and distance, and their separation and length are such that the enhancer means is effective to divert the flux of the vertical deflection field through the openings between the enhancer means. As a result, the vertical height of the raster pattern of the center beam is enhanced into coextensiveness with the raster patterns of the off-axis beams.

Magnetic deflection field enhancer means for television CRT electron guns

A television cathode ray picture tube has an in-line electron gun for generating three coplanar electron beams. The raster pattern projected by the center beam is diminished in vertical height so as to be non-coextensive with the superimposed raster patterns projected by the off-axis beams. The method according to the invention for providing raster coextensiveness comprises embracing each off-axis beam at the point of beam egress from the gun with a pair of inwardly converging but non-intersecting magnetic field enhancer means in symmetrical relationship and defining an opening therebetween. Each member of the enhancer means is oriented at a predetermined convergence angle with respect to the plane of the three beam paths, and located at a predetermined distance from the tube axis. The enhancer means, the predetermined convergence angle and distance, and the separation and length of the enhancer means are such that the enhancer means is effective to divert the flux of the vertical deflection field through the opening between each pair of enhancer means onto the center beam. The height of the raster pattern projected by the center beam is enhanced into coextensiveness with the patterns projected by the off-axis beams.

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Lombard, IL, United States of America

Fred H Seher