Gaseous glow-discharge indicator system

Claim 1

A gaseous glow indicator tube comprising a base plate of insulating material, a transparent cap sealed to said base plate and forming a gas tight chamber therewith, an ionizing gas in said chamber, a sheet of insulating material within said chamber and disposed on said base plate, a plurality of main similarly segmented indicator units within said chamber on the outer face of said sheet, each of said segmented units including a like number of cathode segments similarly located in a predetermined pattern in each indicator unit, at least one anode segment forming a part of each indicator unit and each located on said insulated sheet in the same plane as said cathode segments, a plurality of energizing leads on said insulating sheet corresponding in number to the maximum number of cathode segments in a single indicator unit, secondary leads on the underside of said insulating sheet connected respectively to said cathode energizing leads; means connecting said secondary leads to said cathode segments through said insulating sheet, at least one anode energizing lead for each indicator unit, a secondary lead for each indicator unit connecting the anodes of each indicator unit to an anode energizing lead respectively, a secondary indicator unit in said chamber including at least one cathode segment and one anode segment disposed on said insulating sheet, each cathode segment of said secondary indicator unit being smaller in area than the area of any one of said cathode segments of said main indicator units, an energizing lead for each cathode segment of said secondary indicator unit located on said outer face of said insulating sheet, circuit connections between each of said cathode energizing leads of said secondary indicator unit and associated cathode segment, energizing leads for said anodes of said secondary indicator units connected to their associated anodes respectively, and means for connecting successively said anode energizing circuits to a positive source of potential on a time sharing basis and simultaneously connecting selected ones of said cathode segments of each indicator unit to the negative side of the same source of potential on the same time sharing basis, thereby to cause selected segments of each indicator unit to glow and in which there is provided a resistor element in each cathode segment energizing circuit of said secondary indicator unit, thereby to reduce the current density in each such cathode segment when energized, the resistive value of each resistance element being sufficient to reduce the glow of its associated cathode segment only to a point where the cathode segment is still brighter than the cathode segments of said main indicator units.