Gaseous-flow, discharge display device with an array of hollow cathodes

Claim 1

An electrical display device comprising an envelope, an insulating body having a plurality of cavities therein disposed within the envelope, an electrically conductive cathode at one end of each cavity, the walls of said cavities having a layer of cathode material thereon in contact with said cathodes, electrical supply Conductors for each cathode, said cathodes and the end portions of said conductors which adjoin said cathode lying substantially in one plane, at least one anode within said envelope facing said cathodes and spaced from the edges of said cavities, an ionizable gas filling in said envelope, said anode and said cathodes defining an array of glow discharge paths which extend through the gas, the dimensions and relative locations of said cathodes and said anode and the pressure and composition of said atmosphere being such that with the application of an operating potential across each path negative-glow optical radiation in the resultant glow discharge is generated and is retained within said cavities and the positive column part of the discharge is suppressed.