GB1353189A - Blue lateral magnet structure - Google Patents

Abstract

1353189 Electron beam focusing system RCA CORPORATION 13 May 1971 [15 May 1970] 14767/71 Heading H1D A blue lateral magnet structure for use with a colour kinescope (e.g. three gun triad, shadow mask type) comprises a pair of six-pole magnet rings 10, 20, a support structure 30 having an aperture through which the neck extends, the rings being mounted for eccentric rotation about an axis shifted from the axis of the aperture and means translating rotational motion of either of the rings into a correlated motion of the other of the rings of equal magnitude and opposite sense, the means comprising a drive cord loop, each ring being secured to the cord at a point on opposite sides of the loop. Peripheral tabs 11, 21 may have keyhole shaped notch 12 and circular aperture 22 respectively. Support structure 30 includes arcuate fingers 33 to receive neck 60, forwardly extending arcuate fingers 34 providing outer surfaces for the rotating magnetic rings, and grooved posts 31, 32 around which cord 40 is looped, via notch 12 and aperture 22. Retaining clips 51, 52 lightly hold the mounted rings to support 30, the latter which may also support colour purity adjustment rings (80) (Fig. 2, not shown) with retaining clips 81, 82, and split ring clamp (70) may fix the support 30 on the neck. Midway position of the tab is desirably zero lateral shift position, each ring has an indexing notch 13, 23, at 30 degrees from the tab axis and each tab bent such that the notch is to the left when the tab projects toward the viewer. Each ring is then with a pole of the same polarity aligned with the notch, with no resultant stray field in the neck aperture. Fig. 3 (not shown) indicates a 30-degree rotation with maximum shift of the R, G, B beams in directions shown, the G, B beams in opposite direction to the R beam.