| 摘要 |
A device for correcting residual mis-convergence errors in a color cathode ray tube, the tube including a narrow-necked section, located at the rear thereof, in which electron guns mounted therein generate forwardly-directed red, blue and green electronic beams, an outwardly-opening center skirt section, extending forward from the narrow-necked section, and terminating in a wide perimeter surrounding a relatively flat, pixel-coated, viewing screen section that is arranged generally orthogonal to the axis of the narrow-necked section and upon which the electronic beams are directed to strike the pixels to produce color and images for viewing from the front of the tube, and further having at least one pair of electromagnetic coils mounted outside the tube, for initial focusing of the electron beams during their travel from the guns to the screen, the device including a separator made of a plastic, including a high density of magnetizable particles therein, the separator arranged for placement about the outside of the tube and adapted to receive the electromagnetic coils thereon and, a plurality of small, powerful magnetic poles formed in the separator by at least one application of short-duration, high-voltage charges to various areas on the separator, the location of the magnetic poles determined by measuring the difference between the actual location on the viewing screen where the electron beams strike the pixels and the desired location where the beams are desired to strike the pixels and applying appropriate correction to the paths of the beams using the location and the strength of the magnetic poles.
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