GB1291013A - - Google Patents

Abstract

1291013 Gas-discharge display panels NATIONAL CASH REGISTER CO 10 May 1971 [28 May 1970] 13972/71 Heading H1D A gas-discharge display device includes a cell 40 containing an ionizable gas at a given pressure and means 38, 46 for applying, across said cell, an alternating potential of a magnitude which, at said given pressure, is capable of sustaining ionization in said cell but incapable of initiating ionization therein, wherein said cell is provided with a heating device 30 operable in response to a control signal derived from a control unit 44 to momentarily supply sufficient heat to said cell to raise the pressure of said gas to a value adequate to permit said alternating potential to initiate ionization of said cell. The panel 10 comprises plates 22 and 26 of which at least one, preferably plate 22, is transparent, e.g. glass and has a transparent electrode 28, e.g. of tin oxide, cadmium oxide, or gold deposited thereon and covered by a dielectric coating 38, e.g. glass. Plate 26 has deposited thereon a plurality of thermal electrodes 30 of resistance material such as a nickel-chrome alloy, rhenium, or tantalum, each connected to an input line 32 and an earthed output line 34. Electrodes 30 are covered by a glass layer 36. A third plate 24 has a plurality of holes 40 etched therethrough, each in alignment with an electrode 30. Plates 22, 24 and 26 are sealed together by cement or glass frit. The holes 40 are evacuated and filled with a gas mixture, e.g. Ne+A+N. At least one surface of the plate 24 is roughened to enable gas to diffuse from one cell to another. Electrode 38 is connected to a voltage source 46, and the input lines 32 to electrodes 30 are connected to a current source 42 and a controller 44, e.g. a digit control or a computer, for selectively pulsing the electrodes 30.