Multi-position character display panel having display cathodes and auxiliary cathodes and circuits for operating the same

Claim 1

A display panel and system for operating the same comprising a gas-filled envelope including a base plate and a face plate having a viewing window, a plurality of groups of display cathode electrodes supported on said base plate and adapted to be operated in different combinations to display different characters, corresponding cathodes in all of the groups being interconnected by a single common conductor, there thus being a single common conductor for each corresponding cathode electrode in each of said groups, an auxiliary cathode electrode associated with each said group of display cathodes, an auxiliary common conductor connected to all of said auxiliary cathodes, an anode electrode associated with each said group of cathodes, means coupled to said anodes and said common conductors for sequentially energizing each of said anode electrodes and simultaneously applying information signals to selected ones of said common conductors and their associated display cathodes, and a circuit loop connected between said auxiliary common conductor and all of said single common conductors including means for generating a bias voltage in response to current flow through an auxiliary electrode and applying said bias voltage to all of said display cathodes.

Claim 8

A syStem for operating a multiple position display device having a plurality of groups of display cathode electrodes and an anode electrode associated with each said group, corresponding cathodes in the different groups being interconnected by a single common conductor, there thus being a single common conductor for each corresponding cathode electrode in each of said groups, there being an auxiliary cathode electrode associated with each group of cathode electrodes and auxiliary common conductor interconnecting all of said auxiliary cathode electrodes, said system including an anode driver circuit connected to each of said anode electrodes, a cathode driver connected to each of said common conductors for applying display signals thereto, a bus coupled to all of said common conductors connected to said display cathode electrodes, and a current flow path from each anode through said auxiliary common conductor including means for developing a voltage proportional to current flow therein and for applying said voltage to said bus, said voltage biasing all of said display cathodes at a level such that said display signals, when applied to selected cathode drivers, can cause such cathode drivers to energize the associated display cathodes to exhibit cathode glow.

Claim 9

A syStem for operating a multiple position display device having a plurality of groups of display cathode electrodes and an anode electrode associated with each said group, corresponding cathodes in the different groups being interconnected by a single common conductor, there thus being a single common conductor for each corresponding cathode electrode in each of said groups, there being an auxiliary cathode electrode associated with each group of cathode electrodes and auxiliary common conductor interconnecting all of said auxiliary cathode electrodes, said system including an anode driver circuit connected to each of said anode electrodes, a cathode driver connected to each of said common conductors for applying display signals thereto, a bus coupled to all of said common conductors connected to said display cathode electrodes, and a current flow path from each anode through said auxiliary common conductor including means for developing a voltage proportional to current flow therein and for applying said voltage to said bus, said voltage biasing all of said display cathodes at a level such that said display signals, when applied to selected cathode drivers, can cause such cathode drivers to energize the associated display cathodes to exhibit cathode glow.