Eccentrically mounted six-pole rings for a static convergence unit
AssigneeU.S. Philips Corporation
InventorPiet Gerard Joseph Barten
Life of this patent
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Abstract
Two six-pole annular magnetic structures are arranged about the neck of a three-in-line color display tube so as to be eccentric with respect to each other and with respect to the center of the neck. The center of one six-pole is situated halfway between the central electron beam and one outer electron beam. The two beams on both sides of the center of the six-pole, consequently, are subjected to equal forces of the same direction. The third beam is subjected to a force in the same direction, but this force is nine times larger due to the three times as large distance from the center of the six-pole and due to the square-law field variation thereof. Because of their identical direction and value, the forces acting on the former beams will not disturb the convergence therebetween.
Claims6
In combination with a color display tube having three electron guns arranged in a single plane, a device for the static convergence of electron beams generated by the electron guns, said device enclosing the neck of the color display tube and comprising at least two annular magnetic six-pole structures, which are arranged eccentrically with respect to the neck of the color display tube and to each other, the axis of rotation of a first of said magnetic structures being situated halfway between one outer electron beam and the central electron beam and the axis of the second magnetic structure being situated halfway between the central electron beam and the other electron outer beam.
Dependencies are inferred from the claim text.