US2933648A - Information display apparatus - Google Patents

Description

April 19, 1960 A. D. BENTLEY INFORMATION DISPLAY APPARATUS 2 Sheets-Sheet 1 Filed Aug. 14, 1956 INVENTOR ALBERT D. BENTLEY,

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United States Patent Ofiiice 2,933,643 Patented Apr. 19, 1960 INFORMATION DISPLAY APPARATUS Albert D. Bentley, Schenectady, N.Y., assignor to General Electric Company, a corporation of New York Application August 14, 1955, Serial No. 603,975

12 Claims. or. 315-169) This invention relates to improved information display apparatus of the so-called flat screen type. The invention has particular utility as a large area, small volume display and storage device for reconstituting visual images.

One object of the present invention is to provide an improved information display system characterized by an information display device of simplified construction and associated circuitry of reduced complexity and cost.

Another object is to provide an improved self-luminous relatively thin information display device capable of storing and displaying information with improved contrast and definition of detail in relation to its size.

Another object is to provide a fiat screen display device of the character described which is relatively light in weight. comparatively rugged, not susceptible to implosion, and free of the lift limitations of cathode ray tubes.

Another object is to provide an improved switching system for controlling the operation of a display device of the character described.

These and other objects of the invention will be ap parent from the description following hereinafter, and the scope of the invention will be defined in the appended claims.

Briefly, in a preferred form the display apparatus of the present invention includes a display device of unitary flat construction having a screen or viewing portion including in integral matrix of discrete gas discharge display cells, and having a self-contained switching portion consisting of additional integral gas discharge switching cells. The switching cells are so arranged as to enable either linear scanning of the display cell array or illumination of selected display cells with a minimum number of external leads, and, to facilitate outgassing of the device and gas filling of the cells during manufacture, all cells are connected by pressure equalization passages within the display device.

In the drawings, Figure 1 is a partially broken away perspective view of a portion of an information display device constructed in accordance with the present invention;

Figure 2 is an exploded view of the structure of Figure 1;

Figure 3 is a fragmentary partially broken away elevation view of a portion of the structure of Figure 1;

Figure 4 is a schematic diagram of a portion of an information display system constructed in accordance with the present invention; and

Figure 5 is a block diagram of one form of circuit for producing waveforms of the type shown in Figure 4.

An information display system constructed in accordance with the present invention includes an information display device which, as best shown in Figure 1, is of relatively thin, flat sandwich construction. The display device shown consists of a middle layer 2 and outer layers 4, and 6 which constitute the front and back plates of the device. The outer layers 4, 6 are composed of sheets or panels of electrically non-conducting material,

at least one sheet having a portion translucent to visible light so as to serve as a viewing window or display face of the device. A suitable material for the layers 4, 6, is, for example, glass. The middle layer 2 is also of nonconducting material, and of honeycomb or lattice construction so as to provide a large number of small chambers or small cells 10 arranged preferably side by side in parallel rows and separated by intercellular walls 8. Preferably the cells should be relatively rectangular in cross-section, i.e. in a plane parallel to layer 2, to minimize the thickness of the intercellular walls 8 and provide maximum cell area for a display face of given size. Although in the structure of Figure 1 the layer 2 has only twenty cells 10 by way of illustration, it will of course be appreciated that the device may have many times that number of cells.

One suitable material for-the middle layer is Tomform glass, this material having the desirable property that the pattern of the cells can be applied to it by photo-copying techniques and the cells themselves can thereafter be formed by a relatively simple etching process. Other materials for the middle and outer layers, and other methods of forming the cells may also be used, the invention being in no sense limited to any specific materials for the display device or any specific method of making the cellular or lattice structure. For example, if necessary the cells may be formed by cutting the requisite number of individual holes in the middle layer 2. Preferably the inter-cellular walls or partitions 8 should be relatively opaque, and to this end material for layer 2 of a relatively high opacity is preferred.

Each cell 10 serves as a discrete gas discharge device and to this end each cell is filled with a gas, such as xenon, or a gas mixture, such as mercury vapor and argon or neon, at a low pressure such as four or five millimeters of mercury, capable of being ionized responsive to an application of a suitable potential between the ends of the cell. To augment the flow discharge of the cells and enhance the brightness of the display, there is provided within each cell, as for example by a coating on the side wall of the cell or the portions of the interior surfaces of layers 4 and 6 at the ends of the cell, a luminescent phosphor 12 capable of being excited to luminosity responsive to a glow discharge through the cell. For maximum brightness the phosphor and gas filling are preferably chosen so that the sensitivity spectrum of the phosphor matches the spectrum of radiation from the gas responsive to the glow discharge. Additionally each cell may contain a small amount of radioactive material sufiicient to facilitate rapid ionization of the gas therein.

On the inside surface of one of the outer layers, e.g. the layer 4, is a plurality of linear parallel cathode conductors 16 arranged to extend along the respective rows of cells 10 in one direction, e.g. vertical as shown in Figure 3. On the inner surface of outside layer 6 is a plurality of anode conductors 18 arranged to extend along the rows of cells in the other direction, e.g. horizontal as shown in Figure 3. Conductors 16, 18 may be wires embedded in, cemented to, or otherwise secured to layers 4 or 6, or they may be sprayed, coated or otherwise deposited on layers 4 or 6. Alternatively, of course conductors 16, 18 may be carried by or formed on middle layer 2. The conductors 16 and 18 are so positioned with respect to the cells 10 that each cell coincides with the intersection or crossover point of a respective cathode conductor 16 and a respective anode conductor 18, that is, each cell is crossed at one end by a cathode conductor and at its other end by an anode conductor. T o facilitate initiation and maintenance of a discharge through the cells 10, cathode conductors 16 may if desired have a section of the selected conductors.

coating, filling, or other deposition of a suitable electron emissive material, such as for example barium oxide.

In the assembly of the display device,the three layers of the sandwich 2, 4,, 6, are sealed together at their edges so as to produce a unitary gas-tight structure, with the two outer layers 4, 6 preferably contactingthe middle layer'2 substantially throughout the edges 2% of the intercellular walls 8 so as to substantially exclude gas therebetween except at the locations of the cells. To facilitate outgassing of the display device and filling of the cells with'an appropriate ionizable gas or gas mixture during manufacture, there is provided in accordance with the present invention pressure equalization channels or passageszextending between and connecting the. cells of each row. In the embodiment shown these channels are provided by grooves 22 cut into the inside face of outer layer 4, as best shown in Figure 2. l have found that if the pressure equalization channels 22 are on the cathode side of the device, i.e. in layer 4 or on the side of layer 2 adjacent the cathode conductors 16, these channels 22 should desirably cut across, e.g. be perpendicular to, the cathode conductors as shown in Figure 2. This minimizes spreading out or creeping of the .gas discharge from one cell to others along conductors 16 through the gas in the channels 22. However if the pressure equalization channels 22 are located on the anode side of the device they may be parallel and contiguous to the anode conductors without any undesired creepage. Hence when on the anode side the channels 22 may be either perpendicular or parallel to the anode conductors 1S, and may be of any desired dimension or configuration. Alternatively the channels 22 may be located in the middle layer 2, but this location is less desirable because it increases the possibility of random firing of a cell by line-of-sight radiation from one of its ionized neighbors.

The operation of the display device is as follows, by the application of a potential difference exceeding the gas cell firing potential to a selected cathode conductor 16 and a selected anode conductor 18, ionization and glow discharge will be initiated in the cell at the inter- The necessary firing potential may be applied to only one of the selected. pair of conductors, the other being held relatively at ground, or alternatively a portion of the necessary firing potential may be applied to one of the selected conductors and the remainder of the necessary firing potential of reverse polarity, applied to the other. the gas itself gives oif visible light, and, in addition produces ultra-violet or other invisible radiation which excites the complementary phosphor coating in or coincident with the cell, causing it to luminesce and thus create a bright, clearly visible display. With the construction described the gas filled cells 10 are effectively separate and discrete, and hence the discharge of any one cell is confined thereto, and prevented from spreading to other cells. The relative capacity of the cell walls further contributes to the prevention of the discharge from spreading. Hence any one cell can be lit up while its neighbors remain dark, and thus the display device of the present invention is capable of excellent resolution limited only by the minimum practical display area of each cell.

When the firing potential is removed from the selected cell, deionization occurs and the glow discharge is exting uished. Long persistence phosphors may be used in the cells 3.0, if desired, to obtain delayed extinction of luminosity or, in effect, limited signal storage.

Turning now to Figure 4 there is shown a preferred form of switching arrangement constructed in accordance with the invention for controlling the operation of the information display device so as to enable illumination of selected cells and provide a linear scan of the area covered by the cells 10, similar for example to a television raster scan. In Figure 4, a display device 24 is shown having a viewing portion, framed by line 26, similar in all material respects'to the structure of Figure 1,

The glow discharge of 4 but depicted for simplicity of description hereinafter as having eight rows of eight display cells 10 each. The device 24 of Figure 4 also includes an integral marginal or border portion 27, within which is contained additional rows of switching cells 28. The switching cells serve as non-linear resistances and are preferably similar to cells 10 except for the absence of phosphor 12. However, each cell 28 may consist ofany equivalent resistance element, preferably non-linear, such as for example a thyrite element. The horizontal or anode conductors of the display device of Figure 4 are numbered 41 through 43 and the vertical or cathode conductors are numbered 51 through 58. All cathode conductors are connected through respective load resistors 30 to a terminal 32 to which is connected a negative bias source of magnitude E/2 where E is equal to or greater than the cell firing potential. Likewise all anode conductors are connected through respective load resistors 34 to a terminal 36 to which is connected a positive bias source of magnitude E/ 2.

Alternate cathode conductors 51, 53, 55, 57' are connected, through respective switching cells 61a, 63a, 65a, 67a in the marginal portion of the displayrdevice and a cathode switching conductor 69 similar to anode couductors 18, to a signal voltage 71. Voltage 71 has a period arbitrarily designated 21. is preferably of recng r wa f rm, and. al ernates be we n a magnit E and a magnitude Er, wh re Ea is sufficiently different from E/Z to cause not more than a relatively slight current to flow through a switching cell and E; is suficiently different from E/2 to cause enough current to flow through a switching cell to decrease the potential of the associated cathode conductor below one-half the display cell firing potential.

If the switching cells 28 are gas discharge cells, for example, voltage E may be so related to E/2 that their difierence will not ionize a switching cell and hence no current will be drawn through it, while the difference between Ef and E/2 is sufficient to fire the switching cell. Particularly when the switching cells 28 are gas discharge cells, however, it is preferred to chose E and E relative to E/Z such that a slight current, sufiicient to keep the gas in the cell ionized but insufficient to drop the associated cathode conductor below one-half the display cell firing potential, is drawn through a switching cell when E is applied to it. This. eliminates delays caus d by ioniz ti n nd deionization time, since e switching cells are. never completely deionized.

Cathode conductors 5.2, 54., 56. 58 are li ewise connected through respective switching cells 62a, 64a, 66a, and 68a to a signal 72 of rectangular wave form and magnitude limits similar to signal 71 but having reverse phase. Alternate pairs of cathode conductors 5152, S556 are connected through respective cells 61b, 6 211, 65b,, 66b, to a rectangular wave 73 of period 4p and amplitude limits E and 13;, and the other pairs of cathode concluctors 53-54, 57- 58 are connected through cells 63b, 64b, 67b, 68b to a signal 74 similar to signal 73 but of reverse phase. Cathode conductors 51, 52, 53, 54 are connected through respective switching cells 61c, 62c, 63c, 64c to a signal voltage 75 of rectangular waveform, amplitude limits E and E and period 8;), and conductors 55, 56, 57, 58 are connected through switching cells 65c, 66c, 67c and 680 to a signal 76 similar to signal 75 but of reverse phase.

Similarly alternate anode conductors, alternate pairs thereof, and successive sets of four thereof are connected as shown through respective switching cells 81A-S8C to respective signal voltages 9196 of rectangular Wave form and having respective periods 2P, 4P, and 8? where the period P is a multiple of the period p equals to the number of cathode conductors crossing each anode conductor. Signals 91-96 each alternate between ampliture limits E and E, where E bears the same relation to. E/2 as E; does to E/Z, i.e. causes not more than ,5 a relatively slight current to flow through a switching cell, and E bears the same relation to 15/2 as E, does to E/2, i.e. causes a sufliciently heavy current to flow through a switching cell to drop the associated anode conductor below one half the display cell firing potential.

The application of the signals 7176 and 91-96 to the switching arrangement shown produces a sequential scanning action in the display device in a manner which will now be described. Beginning at a time just after i=0, signal 92 has the value E causing relatively heavy current to flow through cell 82A and dropping the potential of anode conductor 42 sufliciently below E/2 to prevent any of the display cells along anode conductor 42 from firing. Likewise signal 94 has the value E, causing relatively heavy current to flow through cells 83B and 84B and dropping the potential of conductors 43 and 44 sufiiciently below E/2 to prevent firing of any of the display cells along anode conductors 43 and 44. Further, signal 96 has the value E dropping the potential of anode conductors 45, 46, 47, and 48 sufliciently to prevent any of the display cells along these anodes conductors from firing. Signals 91, 93 and 95 have an amplitude E however, so that none of the cells 81A, 81B, 810 connected to line 41 draw more than a relatively light current, and anode conductor 41 thus remains at a potential only slightly below E/2. At the same time signals 72, 74, and 76 all have a magnitude of E causing cells 62a, 63b, 64b, 65c, 66c, 67c, 68c to draw relatively heavy currents and raising the potential of cathode conductors 52 through 58 to a level such as to prevent firing of any of the display cells 10 along cathode conductors 52 through 58. Cathode conductor 51, however, remains at a potential only slightly above -E/2 because signals 71, 73, and 75 all have a magnitude of E and hence none of the cells 61A, 613, or 61C connected to conductor 51 draw relatively heavy currents. Thus, a sufficient voltage difierence exists between conductors 41 and 51 so that the gas in the display cell 10 at the intersection of these conductors is ionized and produces a glow discharge.

At the end of a period of length p after time i=0, the potential of anode conductor 41 remains unchanged, but the voltage E, is switched sequentially from cell 62a to 61a as shown by waveforms 71 and 72. This reduces the current in cell 62a to not more than a relatively slight value, raising conductor 52 to a potential close to E/2 while causing cell 61a to draw a relatively heavy current and raising the potential of conductor 51 sufliciently to extinguish the display cell previously fired. This causes ionization of the gas in the cell at the intersection of conductors 41 and 52, and thus shifts the position of the resulting luminescent spot across the face of the display device in exactly the same manner as the trace of the electron beam in a cathode ray tube. At the end of another time increment, p, signals 74 and 71 change from E; to E allowing conductor 53 to return to a level close to E/2, and signal 72 changes to E raising the potential of conductor 52 to a level such as to prevent firing of any of the display cells therealong. This extinguishes the display cell at the intersection of conductors 41, 52 and shifts the luminescent spot to intersection 41, 53. When the luminescent spot is swept in the foregoing manner to intersection 41, 58, the switching pattern of the cells controlling the bias on conductors 51 through 58 is repeated, causing in efifect a second horizontal trace. However, at this time, i.e. after the elapse of period P, signal 91 goes to E, causing cell 81A to draw a relatively heavy current and dropping the potential of line 41 sufiiciently below E/2 to prevent firing of any of the display cells therealong, while signal 92 goes to E extinguishing the discharge of cell 82A and raising the potential of conductor 42 to a level close to E/ 2. This causes the glow discharge on the display device to move one line down, thereby efiectively producing a sweep corresponding to the vertical sweep of a '6 television raster scan. The process continues until the entire face of the display device has been scanned, whereupon if the signals shown are repeated successive scans or frames will be produced.

With the coherent scanning pattern thus established, selective illumination of particular display cells int he array may be readily achieved by simply keying the application of either or both bias supplies --E/2 or E/2 to terminals 32, 36, as for example by switch or keyer 104, Figure 4. Additionally, a gray scale or variable intensity of illumination of any cell may be achieved with the switching system above described by inserting a conventional current regulating device 105, such as for example a pentode, in series with one of the bias sources. Such an arrangement is shown in Figure 4, wherein current regulating device is connected between terminal 32 and resistors 30 by switch 106, and the efiective resistance of device 105 is varied responsive to a suitable display cell intensity control signal to produce the desired modulation of display cell current, which will in turn vary the brightness of whichever cell 10 is illuminated.

The voltage waveforms 7176 and 9196 shown in Figure 4 may be derived from any suitable remote source, such as the output of a computer or data storage system, or may be generated locally by one or more bistable state devices such as for example a series of binary counters 191, 1132, 103, etc. arranged in cascade form as shown in Figure 5 so as to perform frequency division or multiplication as the case may be.

Alternatively, of course any selected cell may be illuminated by the simultaneous application to the switching cells of potentials corresponding to the values of the waveforms shown at the instant the desired cell would be illuminated by the scanning action above described. Such potentials might be derived from various sources, such as for example the output of a data storage or computing system. i

The number of cathode or anode conductors which may be switched by switching apparatus such as described is equal to 2 where C is the number of binary counters 161, etc. which may be employed. Counters other than binary, such as ring-of-three stages, ring-offour stages, etc. may also be employed. If such counters are used the number of anode or cathode conductors which can be switched equals S where S is the number of stages per counter and C the number of counters. Thus it will be recognized that the above described switching apparatus permits a great reduction in the number of external leads which the display device must have, and greatly simplifies and reduces the cost of the associated circuitry. For example a display device having a. viewing portion consisting of 64x64, or 4096 display cells, can be switched in the manner described by as few as six binary counters for the cathode conductors and six binary counters for the anode conductors, involving a total of only twenty-four external leads.

It will be appreciated by those skilled in the art that the invention may be carried out in various ways and may take various forms and embodiments other than those illustrative embodiments heretofore described. It is to be understood that the scope of the invention is not limited by the details of the foregoing description, but will be defined in the following claims. I

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An information display device comprising a foundation layer consisting of a sheet of insulating material, a middle layer of opaque insulating material superimposed on said foundation layer and a cover layer of insulating material superimposed on said middle layer, means sealing said layers together at their marginal edges to form a gas-tight enclosure, a plurality of cathode conductors extending in one direction adjacent one face of the middle layer, a plurality of anode conductors extending in am "7 other direction adjacent the other face of the middle layer, a plurality of discrete display cells formed by apertures through said middle layer at the respective crossover points of said cathod'e and anode conductors, said cover layer having atranslucent portion through which said display cells may be viewed, and an ionizabic gas filling each of said display cells.

2. An information display device comprising a foundation layer of insulating material, a middle layer of insulating material superimposed on said foundation layer, a cover, layer of insulating material superimposed on said middle layer, means sealing said layers together at'their marginaledges to form a gas-tight enclosure, a plurality of cathode conductors extending in one direction adjacent one face of the middle; layer, a plurality of anode conductors extending in another direction adjacent the other face of the middle layer, a plurality of discrete display cells formed by apertures through said middle layer at the respective cross-over points of said cathode and anode conductors, said cover layer having a translucent portion through which said display cells maybe viewed, an ionizable gas filling each of said display cells, and passages in at least one of said layers extending between said display cells to permit equalization of pressure of the gas filling thereof.

3. A display device as in claim 1 wherein in each cell is a phosphor luminescent responsive to ionization of the gas filling therein said phosphor having a sensitivity spectrum complementary to the radiation spectrum of a glow discharge in said gas filling.

4. An information display device comprising three superimposed panels of insulating material sealed together at their marginal edges to form a gas-tight enclosure, a plurality of space parallel cathode conductors extending in one direction between the middle panel and one outer 'panel, a plurality of spaced parallel anode conductors extending in another direction substantially perpendicular to said one direction between the middle panel and the other outer panel, a plurality of discrete display cells formed by apertures of substantially rectangular cross section through said middle panel at the respective crossover points of said cathode and anode conductors, one of said outer layers having a translucent portion through which said display cells may be viewed, an ionizable gas filling in each of said display cells, and passages in at least one of said. outer panels extending between said display cells to permit equalization of pressure of the gas filling thereof.

5. An information display device comprising three superimposed layers of insulating material, a plurality of discrete. display cells formed by apertures in the middle layer filled with ionizable gas, a translucent portion in one of said outer layers through which said display cellsv may be viewed, a plurality of cathode. conductors between the middle layer and one outer layer and a plurality of anode conductors, between the middle layer and the other outer layer, said cathode and anode conductors having respective cross-over points at each of said display cells, said anode conductors and cathode conductors being adapted to be connected to respective potential sources having a potential. difference not less than the firing voltage of said display cells, means integral with said three layers adapted ,to, control the application of firing voltage to said display cells including switching cells formed by additional apertures through the portion of said middle layer bordering said display cells, and an-ioni'zable gas filling in each of said switching cells.

6. An information display device comprising three superimposed layers of insulating material, a pluraiity of discrete display cells formed by apertures in said middle layer filled with ionizable gas, a translucent portion in one of said outer layers through which said display cells may be viewed, a. plurality of cathode conductors between the middle layer and one outer layer and a plurality of anode conductors between the middlelayerand the other outer adapted to control the application of firing voltage to said display cells including switching cells formed by additional-apertures through the portion of said middle layer bordering said display cells, an ionizable gas filling in each of said switching cells, and passages in at least one of said layers extending between all of said cells, to permit equalization of pressure. of the gas'filling thereof.

7. An information display device comprising three superimposed panels of insulating material sealed together at their marginal edges, a plurality of spaced parallel cathode conductors extending in one direction between the middle panel and one outer panel, a plurality of spaced parallel anode conductors extending in another direction substantially perpendicular to said one direction between the middle panel and the other outer panel, a plurality of discrete display cells formed by apertures through said middle panel atthe respective cross-over points of said cathode and anode conductors, one of said outer layers having a translucent portion through which said display cells may be viewed, an ionizable gas filling each of said display cells, a plurality of spaced cathode switching conductors between said middle panel and said other outer panel, a plurality of discretenon-linear impedance cathode switching elements in said middle panel connecting said cathode conductors. and cathode switching conductors, a plurality of spaced anode switching conductors between the middle panel and said one outer panel, and a plurality of discrete non-linear impedance anode switching elements in said middle panel connecting said anode conductors and anode switching conductors.

8. An information display device comprising three superimposed panels of insulating material sealed together at their marginal edges, a plurality of spaced parallel cathode conductors extending in one direction between the middle paneland one outer panel, a plurality of spaced parallel anode conductors extending in another direction substantially perpendicular to said one direction between the middle panel and the other outer panel, a plurality of discrete display cells formed by apertures through said middle panel at the respective cross-over points of said cells may be viewed, an ionizaole gas filling each of said display cells, a plurality of spaced cathode switching conductors extending in said other direction between said middle panel and said other outer panel, a plurality of discrete cathode switching cells formed by apertures through said middle panel at the respective cross-over points of said cathode conductors, and cathode switching conductors, a plurality of spaced anode switching conductors extending in said one direction between the middle panel and said one outer panel, a plurality of discrete anode switching cells formed by apertures through said middle panel at the respective cross-over points of said anode conductors and anode switching conductors, and an ionizable gas in each of said switching cells.

9. A linearly scannable information display system comprising three superimposed panels of insulating mate: rial, a plurality of cathode conductors extending in one direction adjacent one face of said middle panel, a plurality of anode conductors extending in another direction adjacent the other face of said middle panel, a plurality of discrete display cells formed by apertures through said middle panel at the respective cross-over points of said cathode and anode conductors, an ionizable gas filling in each of said display cells, respective cathode and anode potential sources having a potential difi'erence not less than the firing voltage of said display cells, means for connecting said sets of conductors to said respective potential sources, a plurality C of cathode ring counters of S stages each where S equals the number of said. cathode 9 conductors, non-linear cathode impedance elements connecting successive sets of S S 8 S cathode conductors to successive stages of the first, second, third, Cth cathode ring counter respectively, each of said cathode ring counter stages having an output alternating between potential levels relative to said cathode potential source such as to switch the associated oath ode conductor above and below display cell firing potential relative to the potential of said anode conductors, a plurality D of anode ring counters of T stages each where T equals the number of said anode conductors, nonlinear anode impedance elements connecting successive sets of T T T anode conductors to successive stages of the first, second Dth anode ring counter respectively, each of said anode ring counter stages having an output alternating between potential levels relative to said anode potential source such as to switch the associated anode conductor above and below firing potential relative to the potential ofsaid cathode conductors.

10. A linear scan information display system comprising three superimposed panels of insulating material, a plurality of cathode conductors extending in one direction adjacent one face of said middle panel, a plurality of anode conductors extending in another direction perpendicular to said one direction adjacent the other face of the middle panel, a plurality of discrete display cells formed by apertures through said middle panel at the respective cross-over points of said cathode and anode conductors, an ionizable gas filling in each of said display cells, passages in at least one of said panels extending between said cells to permit equalization of pressure of the gas filling thereof, respective cathode and anode potential sources having a potential difference not less than the firing voltage of said display cells, load impedances connecting each of said anode conductors and cathode conductors to said potential sources, display cell brightness control means including a current regulating device in series with at least one of said potential sources, a plurality C of cathode binary counters where 2 equals the number of said cathode conductors, non-linear cathode impedance elements connecting alternate sets of 2 2 2 2 cathode conductors to alternate stages of the first, second, third, Cth cathode binary counter respectively, each of said cathode binary stages having an output alternating between potential levels relative to said cathode potential source such as to switch the associated cathode conductor above and below firing potential relative to the potential of said anode conductors, a plurality D of anode binary counters where 2 equals the number of said anode conductors, non-linear anode impedance elements connecting alternate sets of 2 2 2 anode conductors to alternate stages of the first, second, Dth anode binary counter respectively, each of said anode binary counter stages having an output alternating between potential levels relative to said anode potential source such as to switch the associated anode conductor above and below firing potential relative to the potential of said cathode conductors.

11. A linear scan information display system comprising three superimposed panels of insulating material, a plurality of cathode conductors extending in one direction adjacent one face of said middle panel, a plurality of anode conductors extending in another direction adjacent the other face of said middle panel, a plurality of discrete display cells formed by apertures through said middle panel at the respective cross-over points of said cathode and anode'conductors, an ionizable gas filling ringcounter respectively, each of said cathode ring 7 in each of said display cells, respective cathode and counter stages having an output alternating between potential levels relative to said cathode potential source such as to switch the associated cathode conductor above and below displayrcell firing potential relative to the potential of said anode conductors, a plurality D of anode .ring counters of T stages each where T equals the number of said anode conductors, and means including anode switching cells formed by additional ionizable gas filled apertures in said middle panel connecting each anode conductor in successive sets of T "E T anode conductors to successive stages of the first, second Dth anode ring counter respectively, each of said anode ring counter stages having an output alternating between potential levels relative to said anode potential source such as to switch the associated anode conductor above and below firing potential relative to the potential of said cathode conductors.

12. Apparatus for linearly scanning an information display device having a plurality of cathode conductors extending in one direction and adapted to be connected through load impedances to a source of cathode potential, a plurality of anode conductors extending in another direction and adapted to be connected through load impedances to a source of anode potential, and a plurality of discrete ionizable-gas-fillecl display cells having a firing potential not greater than the difierence between said cathode and anode potentials and located at the respective cross-over points of said cathode and anode conductors, comprising a plurality of C of cathode ring counters of S stages each were S equals the number of cathode conductors of said display device, non-linear cathode impedance elements adapted to connect successive sets of 8 S S 89- cathode conductors to successive stages of the first, second, third, Cth cathode ring counter respectively, each'of said cathode ring counter stages being adapted to have an output alternating between potential levels relative to the cathode potential source of the display device such as to switch the associated cathode conductor above and below display cell firing potential relative to the potential of the anode conductors of the display device, a plurality D of anode ring counters of T stages each where T equals the number of anode conductors of the display device, non-linear anode impedance elements adapted to connect successive sets of I' T T anode conductors to successive stages of the first, second Dth anode ring counter respectively, each of said anode ring counter stagesbeing adapted to have an output alternat ,ing between potential levels relative to the anode poten-t tial source of the display device such as to switch the associated anode conductor above and below display cell firing potential relative to the potential of the cathode conductors of the display device.

2,500,929 Chilowsky Mar. 21, 1950 Ruderter June 5, 1956'

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