GB1210341A - Raster deviation correction in color cathode ray tubes - Google Patents

Abstract

1,210,341. Colour television tubes. SONY CORP. 5 Feb., 1968 [5 Feb., 1967], No. 6287/69. Heading H1D. In a colour television tube wherein a plurality of beams B B B G B R converge on a grid or shadow mask and are scanned horizontally and vertically across a screen by corresponding magnetic fields produced by a deflection yoke 20, a magnetic correction field is applied to one of the beams in the direction of one of the deflection fields to correct deviations between the rasters of the beams on the screen. In Fig. 5, the beams lie in a common horizontal plane and are converged by electrostatic deflection plates P and Q. Magnetic yoke members Y and Y<SP>1</SP> are mounted on the plates P and P<SP>1</SP> and serve to collect leakage flux from the vertical deflection coils thereby producing a correcting field which acts on the centre beam B G . Each yoke member Y comprises a flat strip with upstanding ends lying transversely across a plate P. The yoke members may additionally be energized by auxiliary external electromagnets. In the deflection yoke 20 the vertical deflection coils are preferably toroidal to produce a barrel-shaped field, and the horizontal deflection coils are saddleshaped to produce a pin-cushion shaped field (Fig. 2, not shown). The deflection plates P and P<SP>1</SP> are supported from the cylindrical grid G 5 by angle members 51. A spring member 55 is secured to a bracing member 54 bridging the free end of the plates to maintain the spacing between the plates, and is connected to a conductive wall coating 56 to which connection may be made by an anode button (not shown). The plates Q are attached to insulating members 53 mounted on support pins 52 extending from plates P; they are connected together by a wire 57 and connected by a wire 59 to a button 58 to which an operating potential may be supplied.