GB505026A - Improvements relating to electric discharge devices and/or circuits therefor - Google Patents

Abstract

505,026. Cathode-ray tubes. COSSOR (HOLDINGS), Ltd., A. C., and WILLIAMS, B. C. FLEMING-. Nov. 3, 1937, No. 30057. [Class 39 (i)] The beam issuing from the electron gun is divid. ed by a plate 7 between the first or only deflect. ing plates 5, 6; the plate 7 is at the same potential as the final anode 4 of the gun, sc that potential applied to the plate 5 or 6, does not affect the field between the plates 6 and 7 or 5 and 7 respectively. Two different controls may be applied to the plates 5 and 6 or only a single variable may be used on one plate. Small additional deflector electrodes 8, 9 may be used, these being cross-connected for bias as shown ; for correction of errors in the beam a small deflection-which may be effected magnetically-may be applied in the gun or between the gun and the plate 7. The deflector plates 5, 8 and the plate 7 are supported by mica discs 10, 11 which have slits. wherein the plates are centred. Dimensions of plates &c. for one construction are given. According to the Provisional Specification the beam may be deflected in one plane by a pair of plates one of which is adjacent the beam; this pair is the farther pair from the screen, the other pair being arranged normally and working push-pull. Trapezium distortion is prevented thereby. In another arrangement the beam is divided into a plurality of ribbons by wires arranged parallel to each other in a plane perpendicular to the gun axis ; in the shadows formed by the wires alternately, further thinner gauge wires or sheet electrodes are arranged to which deflecting potentials are applied. The deflecting wires may be coupled.