Electronic indicia display system

Claim 2

An indicating system for displaying indicia comprising a plurality of indicating devices each having a filament, a plurality of anode segments shaped to display predetermined indicia and a grid for controlling the flow of electrons from the filament to the anodes, means applying a low potential to said filaments, circuit means interconnected with the anode segments of each device for applying a high potential to selected anode segments of said devices in response to the input signal fed to said circuit means and means connected with the grids of said devices for operating selected devices by applying a high potential to the grids of the selected devices and a low potential to the other devices whereby only said selected devices will luminesce to display indicia.

Claim 3

An indicating system according to claim 1 including means for applying a high biasing potential pulse to said filaments of said devices just prior to the termination of said input signal said pulse having a time duration greater than the time required for the termination of said input signal.

Claim 4

An indicating system according to claim 1 wherein each indicating device is enclosed within an envelope and a thin film of electroconductive material such as a metal, metal alloys and the like at least partially surrounding said envelope, said film having a resistivity sufficient to effect electrostatic shielding and a relatively high light transmission characteristic.

Claim 5

An indicating system according to claim 1 including means connecting said filaments in series and to an alternating current source of energy, means including rectifiers connecting said anodes to each side of said alternating current energy source to counteract a forward bias between said anodes and filaments when said filament voltage is in a direction preventing said devices from being maintained in cutoff state.

Claim 6

An indicating system according to claim 1 wherein said indicating devices are enclosed within a common envelope.

Claim 7

An indicating system according to claim 5 wherein corresponding anodes of said indicating devices are interconnected within said envelope and lead wires connected to said interconnected anodes and each of said grids are connected to individual conductors extending outwardly through said envelope.

Claim 8

An indicating system according to claim 5 including electrostatic shields between adjoining devices within said envelope prevent electronic interference between adjoining devices.

Claim 9

An indicating system for displaying indicia comprising a plurality of indicating devices each including a cathode, a plurality of phosphor coated anode segments shaped to display predetermined indicia and a grid between said cathode and anode segments for controlling electron flow to said segments, means including a power source connected with said cathodes to constantly maintain them at a selected operating temperature for the emission of electrons and at a relative low potential, connections between corresponding anode segments of said devices, an anode selecting circuit connected to said anode connections and applying a high potential relative to the cathode potential to selected sets of anode segments, means feeding a numerical input signal to said anode selecting circuit to cause the latter to apply said high potential to selected sets of anode segments while the remaining sets of anode segments remain at a low potential, a timing pulse generator for generating a plurality of timing pulses shifted in phase and synchronized with the input signal, grid timing circuit means connected with the grids of said devices and with the timing pulse generator to apply a high potential relative to the cathode potential to the grids of selected devices while the grids of the remaining devices remain at a low potential whereby selected devices wherein both anode segments and the grid are at a high potential will luminesce to display the selected indicia.

Claim 10

An indicating system for displaying indicia comprising a plurality of indicating devices each including a cathode, a plurality of phosphor coated anode segments shaped to display predetermined indicia and a grid between said cathode and anode segments for controlling electron flow to said segments, means including a power source connected with said cathodes to constantly maintain them at a selected operating temperature for the emission of electrons and at a relative low potential, connections between corresponding anode segments of said devices, an anode selecting circuit connected to said anode connections and applying a high potential relative to the cathode potential to selected sets of anode segments, means feeding a numerical input signal to said anode selecting circuit to cause the latter to apply said high potential to selected sets of anode segments while the remaining sets of anode segments remain at a low potential, a timing pulse generator for generating a plurality of timing pulses shifted in phase and synchronized with the input signal, grid timing circuit means connected with the grids of said devices and with the timing pulse generator to apply a high potential relative to the cathode potential to the grids of selected devices while the grids of the remaining devices remain at a low potential whereby selected devices wherein both anode segments and the grid are at a high potential will luminesce to display the selected indicia.

Claim 11

An indicating system according to claim 8 including means connected to said cathodes for applying a high potential thereto at selected switching times to momentarily drive said devices into a cutoff state.

Claim 12

An indicating system according to claim 8 wherein said anode selecting circuit includes a plurality of transistors each having a collector connected to one set of anode segments and to a low voltage source, an emitter connected to a high voltage source and a base connected to said input signal means, and said grid timing circuit means includes a plurality of transistors each having a collector connected to one of said grids and to a low voltage source, an emitter connected to a high voltage source and a base connected to the timing pulse generator.