Gas discharge character display tube with apertured mica plate

Claim 1

A gas discharge tube for displaying at least two characters, comprising an envelope having flat front and rear glass walls and containing an ionizable medium, a plurality of adjacent matrix groups within said envelope, the matrix elements in at least one group comprising two plate-shaped anodes and elongate cathode strips which are arranged around said two plate-shaped anodes as a stylized 8, an additional anode associated with each of said matrix groups, both the cathode strips and the anodes each forming one assembly, supply conductors secured in a vacuum-tight manner to the glass rear wall by means of enamel, a frame of sintered glass connecting said front and rear walls, a mica plate having openings therein to expose the active front sides of the electrodes, said mica plate being clamped between bent parts of the supply conductors and parts of strips fixed by means of enamel with the supply conductors to the rear wall, the distance between the front wall and the rear wall being determined by parts of said strips bent at right angles to the rear wall, the conductors and parts being fixed by enamel to the rear wall only below the frame of sintered glass and the flat-plate anodes being moreover fixed by enamel to the rear wall over a part of their surface.