GB1142811A - Gas discharge indicator tubes - Google Patents

Abstract

1,142,811. Glow discharge indicator tubes. METRIMPEX MAGYAR MUSZERIPARI KULKERESKEDELMI VALLALAT. 11 March, 1966, No. 10889/66. Heading H1D. A glow discharge tube includes: a stack of cathodes, shaped or slit to provide a display in the form of a numeral, and spaced from one another, and conductively connected together by metal members of a work function higher than that of the material constituting the cathode display surfaces, each cathode 1 having a portion, at least part of the surface of which is constituted by molybdenum, extending towards the single common anode 3; and a corresponding set of control electrodes 5 respectively disposed in or extending into the spaces between the cathode extensions and the anode. The anode, which may surround the cathode stack, and the control electrodes are biased with respect to the cathodes such that a small signal applied to a control electrode produces a discharge between itself and the corresponding cathode extension, which subsequently spreads to the anode and the complete cathode surface. The tube has a rare gas filling, and the cathodes may be of aluminium, and spaced by nickel members, or the cathode may be coated with a metal of suitable work function. In another embodiment (Fig. 3, not shown), the numeral shapes are formed by slit arrays in the cathode plates, the edges of the slits being coated with a suitable metal, and the anode, in the form of a disc having slits corresponding to those in the cathodes, being mounted in front of the cathodes with a portion extending down a part of the periphery of the cathode stack; in this embodiment, a phosphor-coated transparent screen may be mounted in front of the anode.