GB857615A - Improvements in or relating to electron discharge devices and to targets therefor - Google Patents

Abstract

857,615. Cathode-ray tubes. WESTERN ELECTRIC CO. Inc. March 21, 1958 [March 27, 1957], No. 9152/58. Class 39(1). In a pulse code modulation or other cathode ray tube the target is a grooved block each groove having a wire electrode therein to collect secondaries emitted by the block groove surfaces the grooves being so arranged that the wire electrodes are shielded from the primary electron beam. The tube may be used for monitoring memory devices and the beam is of strip form. The wire electrodes have individual terminals. The collector block 10, preferably of aluminium has its grooves inclined by about 60 degrees, e.g. 63 degrees, to the plane of the front face and their exposed sides is oxidised to increase the secondary emission therefrom. The target wires pass through individual guide slots 28 in ceramic e.g. steatite end blocks 11 and go across slots 22 to individual Mo terminals 12 connected to individual button terminals 15, the structure being similar at both ends of wires 19. Thermal expansion and contraction effects of the Monel wires 19 are minimised by forming metal end plates 14 with integral spring flaps 20 having curved free ends pressing against insulating pins 21. The tube also has shields 6 and 8, the latter having a rectangular aperture for passage of the strip beam. Shield 6 has brackets 7 supported from the envelope by braces 31 and a first set of insulating support rods 4, while the shield 8, coder plate and collector structure are supported from shield 6 by a second set of insulating support rods 5. Biasing leads 17, one of which is connected to shield 8 are connected to end button terminals 13 The gun. includes main deflecting members and tilt correcting members supported by the first set of rods 4, and is preferably constructed as described in Specification 723,504. Specification 679,730 also is referred to.