Drive signal storage and direct drive in display systems

Claim 2

Multiple-position display device and system for operating the device, said device having a plurality of groups of cathode elements and an anode associated with each group, corresponding cathodes of the different groups being interconnected by a single common conductor, there thus being a single common conductor for each cathode element in each of said groups, said system comprising first means for applying positive-going signal voltages coupled to each of the anodes individually and sequentially, anodes not so addressed being held off by a potential lower than said positive-going signal voltages, a capacitor having one side coupled to each of the single common conductors and thus to one cathode element in each group to provide drive currents directly to them at a potential suitable to activate selected cathode elements at a display position having an addressed anode, the other side of each said capacitor being coupled to a data line at the output of a source of data signals, and second means coupled to each said capacitor for charging each said capacitor proportionally to the number of data lines which carry data signals and in a direction to cause the associated cathode element to exhibit cathode glow.

Claim 3

The system defined in claim 1 wherein said second means includes an active element providing a current flow path coupled to said capacitor, and another capacitor coupled to the input of said active element, said other capacitor being coupled to all of said common conductors whereby the charge thereon is proportional to the number of data lines which carry data signals.

Claim 4

The system defined in claim 1 wherein said first means includes a separate signal output line coupled to each of said anode electrodes and through a diode to a bus which is connected to a resistor for applying holdoff bias potential to all of said anode electrodes which do not receive a positive-going signal voltage, said bus also being coupled through an active element which is coupled to said first capacitor.

Claim 5

The system defined in claim 1 wherein said first means includes a separate signal output line coupled to each of said anode electrodes and through a diode to a first bus which is connected to a resistor for applying holdoff bias potential to all of said anode electrodes which do not receive a positive-going signal voltage, said first bus also being coupled to a first semiconductor device having an output electrode coupled to a first path including a second capacitor and a resistor in series, a second bus coupled Through a resistor to each of said common conductors, a second semiconductor device coupled to said second bus to provide current thereto, the output of said first semiconductor device being coupled through said first path to the input of said second semiconductor device and to said second bus through a second path including diode means and resistive means in parallel.

Claim 6

Multiple-position display device and system for operating the device wherein said device has a plurality of groups of cathode elements and an anode associated with each group, corresponding cathodes of the different groups being interconnected by a single common conductor, there thus being a single conductor for each cathode element in each of said groups, said apparatus comprising a source of data signals, first means for applying positive-going signal voltages coupled to each of the anodes individually and sequentially, anodes not so addressed being held off by a potential lower than said positive-going signal voltages, a capacitor having one side coupled to each of the single common conductors and thus to one cathode element in each group to provide drive currents directly to them at a potential suitable to activate selected cathode elements at a display position having an addressed anode, the other side of each said capacitor being coupled to a data line at the output of said source of data signals, second means coupled to each said capacitor for charging each said capacitor to a first level below cathode ionization potential at which a cathode exhibits cathode glow, and third means coupled between said source of data signals and each of said capacitors for charging each said first capacitor to a second level equal to or greater than cathode ionization potential when a data signal is present at said third means, said first means including a separate lead connected from said data source to each said anode and through a resistive path to first and second semiconductor devices in series, a bus coupled through separate diodes to each of said capacitors, the output of said first and second semiconductor devices being connected to said bus for applying holdoff potentials thereto and to said capacitors when said first and second semiconductor devices are in a conductive state, said capacitors being charged to said first level when said first and second devices are in said conductive state, said first and second semiconductor devices being turned off and said third means being selectively energized when information signals are present.

Claim 7

Multiple-position display device and system for operating the device wherein said device has a plurality of groups of cathode elements and an anode associated with each group, corresponding cathodes of the different groups being interconnected by a single common conductor, there thus being a single conductor for each cathode element in each of said groups, said apparatus comprising a source of data signals, first means for applying positive-going signal voltages coupled to each of the anodes individually and sequentially, anodes not so addressed being held off by a potential lower than said positive-going signal voltages, a capacitor having one side coupled to each of the single common conductors and thus to one cathode element in each group to provide drive currents directly to them at a potential suitable to activate selected cathode elements at a display position having an addressed anode, the other side of each said capacitor being coupled to a data line at the output of said source of data signals, second means coupled to each said capacitor for charging each said capacitor to a first level below cathode ionization potential at which a cathode exhibits cathode glow, and third means coupled between said source of data signals and each of said capacitors for charging each said first capacitor to a second level equal to or greater than cathode ionization potential when a data signal is present at said third means, said first means including a separate lead connected from said data source to each said anode and through a resistive path to first and second semiconductor devices in series, a bus coupled through separate diodes to each of said capacitors, the output of said first and second semiconductor devices being connected to said bus for applying holdoff potentials thereto and to said capacitors when said first and second semiconductor devices are in a conductive state, said capacitors being charged to said first level when said first and second devices are in said conductive state, said first and second semiconductor devices being turned off and said third means being selectively energized when information signals are present.

Claim 8

Multiple-position display device and system for operating the device wherein said device has a plurality of groups of cathode elements and an anode associated with each group, corresponding cathodes of the different groups being interconnected by a single common conductor, there thus being a single common conductor for each cathode element in each of said groups, said apparatus comprising a source of data signals, first means for applying positive-going signal voltages coupled to each of the anodes individually and sequentially, anodes not so addressed being held off by a potential lower than said positive-going signal voltages, a capacitor having one side coupled to each of the single commmon conductors and thus to one cathode element in each group to provide drive currents directly to them at a potential suitable to activate selected cathode elements at a display position having an addressed anode, the other side of each said capacitor being coupled to a data line at the output of said source of data signals, second means coupled to each said capacitor for charging each said capacitor to a first level below cathode ionization potential at which a cathode exhibits cathode glow, and third means coupled between said source of data signals and each of said capacitors for charging each said first capacitor to a second level equal to or greater than cathode ionization potential when a data sIgnal is present at said third means, said first means including a separate lead connected from said data source to each said anode and through a resistive path to first and second semiconductor devices in series, a bus coupled through separate diodes to each of said capacitors, the output of said first and second semiconductor devices being connected to said bus and to a current flow path which includes a first diode, said capacitor, a second diode, a resistor and a source of bias potential whereby each of said capacitors is charged to a relatively low level and holdoff potential is applied to each of said common conductors and said cathode elements do not exhibit cathode glow, said third means including separate semiconductor devices connected between said data source and each of said capacitors, each of said separate semiconductor devices being in a conducting state when no data signals are applied to it from said data source whereby its associated capacitor is held at said low level, each said capacitor being charged to a relatively high level at which its associated cathode can exhibit cathode glow when said first and second semiconductor devices are not conducting, and its associated separate semiconductor device receives data signals from said data source and is not conducting.

Claim 9

Multiple-position display device and system for operating the device wherein said device has a plurality of groups of cathode elements and an anode associated with each group, corresponding cathodes of the different groups being interconnected by a single common conductor, there thus being a single common conductor for each cathode element in each of said groups, said apparatus comprising a source of data signals, first means for applying positive-going signal voltages coupled to each of the anodes individually and sequentially, anodes not so addressed being held off by a potential lower than said positive-going signal voltages, a capacitor having one side coupled to each of the single commmon conductors and thus to one cathode element in each group to provide drive currents directly to them at a potential suitable to activate selected cathode elements at a display position having an addressed anode, the other side of each said capacitor being coupled to a data line at the output of said source of data signals, second means coupled to each said capacitor for charging each said capacitor to a first level below cathode ionization potential at which a cathode exhibits cathode glow, and third means coupled between said source of data signals and each of said capacitors for charging each said first capacitor to a second level equal to or greater than cathode ionization potential when a data sIgnal is present at said third means, said first means including a separate lead connected from said data source to each said anode and through a resistive path to first and second semiconductor devices in series, a bus coupled through separate diodes to each of said capacitors, the output of said first and second semiconductor devices being connected to said bus and to a current flow path which includes a first diode, said capacitor, a second diode, a resistor and a source of bias potential whereby each of said capacitors is charged to a relatively low level and holdoff potential is applied to each of said common conductors and said cathode elements do not exhibit cathode glow, said third means including separate semiconductor devices connected between said data source and each of said capacitors, each of said separate semiconductor devices being in a conducting state when no data signals are applied to it from said data source whereby its associated capacitor is held at said low level, each said capacitor being charged to a relatively high level at which its associated cathode can exhibit cathode glow when said first and second semiconductor devices are not conducting, and its associated separate semiconductor device receives data signals from said data source and is not conducting.

Claim 10

Multiple-position display device and system for operating the device, said device comprising a gas-filled envelope including a plurality of groups of cathode electrodes and an anode associated with each group, corresponding cathodes of the different groups being interconnected by a single common conductor, there thus being a single common cathode conductor for each cathode electrode in each of said groups, said system comprising a first bus connected to all of said common conductors, a semiconductor logic circuit including: a plurality of output leads, each coupled through a capacitor to one of said common cathode conductors for applying data signals thereto, an anode lead coupled to each of said anodes, a plurality of input leads, and means by which a clock signal can be applied to the logic circuit to sequence the logic circuit, and a keyboard having: a plurality of keys, each representing a unit of information; a plurality of output leads, one from each key and connected to one of said input leads to said logic circuit; and a plurality of strobe leads, each connected to one of said anode leads of said logic circuit and thus to one of said anodes, each of said anode leads and the keyboard strobe lead to which it is connected being coupled through a pulse-generating circuit to said bus which is connected to said common cathode conductors, whereby at a character position when the anode is energized and driven in a positive direction, all of said common cathode conductors and one side of said capacitor are driven in a negative direction, the presence of a cathode data signal on any one of said output leads from said logic circuit appearing at the other side of the associated one of said capacitors and driving the associated common cathode conductor sufficiently negative to cause the cathode associated with the energized anode to exhibit cathode glow, the absence of a cathode data signal on any one of said output leads from said logic circuit preventing any of said capacitors from charging to a potential sufficient to cause the associated cathode to exhibit cathode glow.

Claim 11

Multiple-position display device and system for operating the device, said device comprising a gas-filled envelope including a plurality of groups of cathode electrodes and an anode associated with each group, corresponding cathodes of the different groups being interconnected by a single common conductor, there thus being a single common cathode conductor for each cathode electrode in each of said groups, said system comprising a first bus connected to all of said common conductors, a semiconductor logic circuit including: a plurality of output leads, each coupled through a capacitor to one of said common cathode conductors for applying data signals thereto, an anode lead coupled to each of said anodes, a plurality of input leads, and means by which a clock signal can be applied to the logic circuit to sequence the logic circuit, and a keyboard having: a plurality of keys, each representing a unit of information; a plurality of output leads, one from each key and connected to one of said input leads to said logic circuit; and a plurality of strobe leads, each connected to one of said anode leads of said logic circuit and thus to one of said anodes, each of said anode leads and the keyboard strobe lead to which it is connected being coupled through a pulse-generating circuit to said bus which is connected to said common cathode conductors, whereby at a character position when the anode is energized and driven in a positive direction, all of said common cathode conductors and one side of said capacitor are driven in a negative direction, the presence of a cathode data signal on any one of said output leads from said logic circuit appearing at the other side of the associated one of said capacitors and driving the associated common cathode conductor sufficiently negative to cause the cathode associated with the energized anode to exhibit cathode glow, the absence of a cathode data signal on any one of said output leads from said logic circuit preventing any of said capacitors from charging to a potential sufficient to cause the associated cathode to exhibit cathode glow.

Claim 12

The system defined in claim 7 and including a second bus, said pulse generating circuit including a first semiconductor device having input and output electrodes and a current flow path therethrough, and a second semiconductor device having input and output electrodes and a current flow path therethrough, all of said anodes being connected to said second bus, said second bus itself being coupled (1) through an anode pull-down resistor to a negative power supply, and (2) to the input of said first semiconductor device of said pulse-generating circuit, The output of said first semiconductor device of said pulse-generating circuit being coupled through another capacitor and a resistive path (1) to the input of said second semiconductor device, (2) to the current flow path through said second semiconductor device, and (3) to said first bus, said first bus thus being connected to said current flow path through said second semiconductor device and to all of said common cathode conductors.

Claim 13

Multiple-position display device and system for operating the device, said device comprising a gas-filled envelope including a plurality of groups of cathode electrodes and an anode associated with each group, corresponding cathodes of the different groups being interconnected by a single common conductor, there thus being a single common cathode conductor for each cathode electrode in each of said groups, said system comprising a first bus connected through individual coupling capacitors to each said common conductor, a semiconductor logic circuit including: a plurality of output leads, each coupled through a separate pulse-generating semiconductor device and one of said coupling capacitors to one of said common cathode conductors for applying data signals thereto, an anode lead coupled to each of said anodes, a plurality of input leads, and means by which a clock signal can be applied to the logic circuit to sequence the logic circuit, a single common pulse-generating circuit, and a keyboard having: a plurality of keys, each representing a unit of information; a plurality of output leads, one from each key and connected to one of said input leads to said logic circuit; and a plurality of strobe leads, each connected to one of said anode leads of said logic circuit and thus to one of said anodes, each of said anode leads and the keyboard strobe lead to which it is connected being coupled through said common pulse-generating circuit to said bus and thus through each said coupling capacitor to one of said common cathode conductors, whereby at a character position when the anode is energized and driven in a positive direction, if the associated pulse-generating semiconductor device receives a data signal from said logic circuit, then the associated cathode exhibits cathode glow.

Claim 14

Multiple-position display device and system for operating the device, said device comprising a gas-filled envelope including a plurality of groups of cathode electrodes and an anode associated with each group, corresponding cathodes of the different groups being interconnected by a single common conductor, there thus being a single common cathode conductor for each cathode electrode in each of said groups, said system comprising a first bus connected through individual coupling capacitors to each said common conductor, a semiconductor logic circuit including: a plurality of output leads, each coupled through a separate pulse-generating semiconductor device and one of said coupling capacitors to one of said common cathode conductors for applying data signals thereto, an anode lead coupled to each of said anodes, a plurality of input leads, and means by which a clock signal can be applied to the logic circuit to sequence the logic circuit, a single common pulse-generating circuit, and a keyboard having: a plurality of keys, each representing a unit of information; a plurality of output leads, one from each key and connected to one of said input leads to said logic circuit; and a plurality of strobe leads, each connected to one of said anode leads of said logic circuit and thus to one of said anodes, each of said anode leads and the keyboard strobe lead to which it is connected being coupled through said common pulse-generating circuit to said bus and thus through each said coupling capacitor to one of said common cathode conductors, whereby at a character position when the anode is energized and driven in a positive direction, if the associated pulse-generating semiconductor device receives a data signal from said logic circuit, then the associated cathode exhibits cathode glow.

Claim 15

The system defined in claim 9 and including a second bus, a third bus, a fourth bus, and a fifth bus, said second bus being coupled through an anode pull-down resistor to a negative power source and to the input of said pulse-generating circuit, the output of said pulse-generating circuit being coupled to said first bus, said first bus being coupled through a diode to the side of each of said capacitors remote from the associated common cathode conductor, each said separate pulse-generating semiconductor device being coupled to said side of its said capacitor through its output electrode, each of said data lines being coupled to the input of one of said pulse-generating semiconductor devices.

Claim 16

The system defined in claim 10 wherein said pulse-generating circuit comprises first and second PNP transistors connected in series, and each said pulse-generating semiconductor device comprises a third PNP transistor.

Claim 17

The system defined in claim 10 wherein said pulse-generating circuit comprises first and second PNP transistors connected in series, and each said pulse-generating semiconductor device comprises a third PNP transistor, said second bus being connected to the base of said first PNP transistor, said third bus being connected through a resistive path to the base of each of said third PNP transistors, said fourth bus being connected to the emitter of each of said third transistors, and said first bus being connected to the collector of said second PNP transistor.