US3826949A

US3826949A - Display device and method of making the same

Info

Publication number: US3826949A
Application number: US00266629A
Authority: US
Inventors: T Nakamura; A Ohgoshi; S Muramoto
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 1971-07-01
Filing date: 1972-06-27
Publication date: 1974-07-30
Anticipated expiration: 1991-07-30
Also published as: DE2232175C2; NL7209116A; DE2232175A1; IT962345B; FR2144435A5; GB1401062A; JPS5422067B1; CA959531A

Abstract

A method of making a display device having steps of forming a first electrode array including a plurality of electrodes, forming an insulating layer on the first electrode array, forming a second electrode array including a plurality of electrodes so as to cross the first electrode array, and forming apertures corresponding to cross-points of the plurality of electrodes of the first and second electrode arrays to be filled with an ionizable gas therein. A display device having selecting electrode plates in addition to the first and second electrode arrays and apertures formed therethrough.

Description

United States Patent 1191 Nakamura et a1.

DISPLAY DEVICE AND METHOD OF MAKING THE SAME Inventors: Toshifumi Nakamura; Akio Ohgoshi; Shoicho Muramoto, all of Tokyo, Japan Assignee: Sony Corporation, Tokyo, Japan Filed: June 27, 1972 App]. No.: 266,629

- Foreign Application Priority Data July 1, 1971 Japan 46-48220 US. Cl. 315/169 R, 313/l09.5 Int. Cl H0lj l/02, HOSb 41/00 Field of Search 315/169 R, 169 TV;

References Cited UNITED STATES PATENTS 10/1960 Bovverman 315/169 R 1451 July 30, 1974 3,042,823 7/1962 Willard 315/169 R 3,673,461 6/1972 Eisenberg 315/169 TV Primary Examiner-Herman Karl Saalbach Assistant ExaminerRichard A. Rosenberger Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [5 7 ABSTRACT 3 Claims, 31 Drawing Figures PAIENIEnJuLamm SHEET 3 0F 8 5a z'm 214/ 7 ammmm ttUJIri wwm PMENH' JULEOHM 3,826,949

SHEEI 7 BF 8 Fig-I] DISPLAY DEVICE AND METHOD OF MAKING THE SAME BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of making a display device, and particularly to a display device which will easily and positively display complicated letters, figures, patterns and so on.

2. Description of the Prior Art Visual display devices are known in which a plurality of gas-filled, cold-cathode discharge tubes are arranged in the rows and columns of a rectangular corrdinate matrix with one transparent electrode of each tube in a row connected to an associated row conductor and the other transparent electrode of each tube in a column connected to a block. One set of conductors is formed on the surface of a further block which is subsequently sealed to the block containing cavities. Each of such conductors is usually a transparent evaporated layer of a suitable material. The other set of conductors is not produced in the same manner since it is necessary to provide a series resistance for each discharge tube, and this is done externally.

The separate resistance necessary for each discharge tube also has a resistor to an associated column conductor. A selected one of the tubes may be struck or extinguished by the variation of potentials applied to the row conductor and column conductor which uniquely define the selected tube.

Dlsplay devices of this type using discrete discharge tubes are necessarily bulky, and attempts have been made to reducethe size of the array of such discharge devices. To this end, arrays of discharge tubes have been produced in which each discharge tube is formed with a cavity in glass or ceramic for limiting effect on the size of the array, since each resistor has to be connected separately. Hence, large arrays having rows and columns, each containing a number of discharge tubes, present considerable problems. Further, such a display device, becomes high in cost because it employs a transparent electrode.

Another. display device is also known in which ordinary conductive metal is arranged in row and column through an insulating material. In this type of display device, a plurality of bores are previously formed through the insulating material at the positions where the row and column electrodes intersect each other. Row electrodes, each of which has formed therethrough openings at the positions corresponding to those of the bores of the insulting layer, are attached to one surface of the insulating layer for the bores and openings to be aligned with each other, and column electrodes, each of which has also formed therethrough openings at positions corresponding to those of the insulating layer, are attached to the other surface of the insulating layer for both openings and bores to be aligned. The insulating layer with the row and column electrodes is inserted into an envelope together with ionizable gas and then the envelope is sealed up.

With such a display device, it is rather complicated work to assemble the insulting layer and row and column electrodes with their bores and opening being in coincidence with one another and if all the bores and openings do not coincide correctly with one another,

SUMMARY OF THE INVENTION This invention relates to a novel display device and to a novel method of making it, which display device includes row and column electrodes or electrodearrays mounted on an insulating layer on both its surfaces, and bores are formed through the insulating layer corresponding to the intersecting points of the row and column electrodes and openings are also formed in one of the row and column electrodes at the positions corresponding to their intersecting points, the bores and opening serving for discharge.

It is an object of this invention to propose a method of making a display device easily which displays letters, figures, patterns or the like.

It is another object of this invention to propose a method of making a display device which displays clearly letters, figures, patterns and the like.

It is a further object of this invention to propose a method of making a display device which displays letters, figures, patterns and the like in small size clearly.

It is a still further object of this invention to provide a display device which is compact and free from indication error.

It is yet another object of this invention to provide a display device which displays letters, figures, patterns and the like without crosstalks therebetween.

The other objects, features and advantages of this invention will be apparent from the description taken in conjunction with the accomapnying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view schematically illustrating one example of the display device according to this invention;

FIG. 2 is a plan view illustrating a base plate of the display device illustrated in FIG. 1 and with a plurality of first electrodes and a plurality of connecting leads formed on the base plate;

FIG. 3 is a plan view of the base plate shown in FIG. 2 with an insulating layer formed over the plurality of electrodes and connecting leads;

FIG. 4 is a plan view of the base plate shown in FIG. 3 with a plurality of second electrodes formed over the insulating layer;

FIG. 5 is a plan view of the base plate shown in FIG. 4 with an insulating layer formed over the second electrodes;

FIG. 6 is a plan view of the base plate shown in FIG. 5 with a plurality of third electrodes formed over the insulating layer;

FIG. 7 is a plan view of the base plate shown in FIG. 6 with a plurality of apertures formed through the electrodes and insulating layers;

FIG. 8 is an enlarged sectional view taken along the line 8-8 in FIG. 7;

FIG. 9 is a sectional view taken along the line 99 in FIG. 1;

FIG. 10 is a schematic circuit diagram of the display device shown in FIG. 1;

FIGS. 1 1A to 11L, inclusive, are wave form diagrams showing voltages applied to the respective electrodes shown in FIG. 10;

FIG. 12 is a graph showing the relationship between voltage applied to the third electrode and voltage to initiate electric discharge;

FIG. 13 is a plan view of a base plate with a plurality of firstelectrodes of a second example of the display device according to this invention;

FIG. 14 is a plan view of the base plate shown in FIG. 13 with an insulating layer, a plurality of second electrodes and a plurality of apertures formed through the second electrodes and the insulating layer, respectively;

FIG. 15 is an enlarged sectional view of a part of the base plate in FIG. 14;

FIG. 16 is a cross-sectional view showing a part of electrode of a third example of the display device according to this invention;

FIG. 17 is a cross-sectional view of the electrode shown in FIG. 16 with a cover plate;

FIG. 18 is an enlarged plan view of one part of the electrode shown in FIG. 17;

FIG. 19 is a cross-sectional view showing partially electrodes of another example of this invention; and

FIG. 20 is a cross-sectional view of the part shown in FIG. 19 which is worked out.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 and 9 there is illustrated generally one example of a gaseous glow type display device 1 produced according to this invention. The display device 1 comprises a base plate 2 made of an insulating material such, for'example, as glass. A plurality of indicator units, in this case three units, 11,12 and 13 of the same pattern are formed by printing techniques on the base plate 2 in alignment with one another. A transparent cover plate 3, as made of, for example, glass, is'attached at its periphery in-an airtight manner to the base plate 2 to cover the indicator units 11 to 13 therein and it is spaced by a predetermined distance from the indicator units 11 to 13.

The display device 1 of this present invention is constructed in the following manner: The insulating base plate 2 with the indicator units 11 to 13 and the leads as shown in FIG. 1 is provided. The transparent cover plate 3, which has formed with a depressed portion 4 is attached to the base plate 2 at its periphery to cover the indication units 11 to 13 therein as shown in FIG. 9.

The base plate 2, as shown in FIG. 2, has mounted thereon a plurality of first electrodes 21 to 25, inclusive, serving as row cathode electrodes, connecting leads 21a to 25a, inclusive, therefor, a plurality of connecting leads 26a to 29a, inclusive, to be connected to second electrodes which will be described later and a plurality of connecting leads 30a to 32a, inclusive, to be connected third electrodes which will be also described later. The electrodes 21 to 25 and connecting leads 21a to 32a are respectively fonned on one surface of the base plate 2 by suitable thin film techniques such as, for example, by printing and baking. After the first electrodes 21 to 25 and the plurality of connecting leads 21a to 32a are respectively formed on the base plate 2, an insulating layer 40 is formed over the entire surface of the base plate 2 except terminal parts of the connecting leads 21a to 32a as shown in FIG. 3. In addition, small apertures 46a to 49a, 46b to 49b, 460 to 49c and 51 to 53 are bored through the insulating layer 40. The apertures 41a to 49 correspond .to the connecting leads 26a to 29a, respectively, and the apertures 51 to 53 correspond to the connecting leads 30a to 32a, respectively. The insulating layer 40 may be formed, for example, by theso-called silk screen process in the same manner as the electrodes and connecting leads are formed. The insulating layer 40 also may be formed, for example, of glass frit" and maybe formed by coating the glass frit on the base plate 2 two or three times and then drying and heating.

FIG. 4 illustrates the next step of the method of making the display device in which a plurality of second electrodes 66a to 69a, 66b to 69b and 660 to'69c are formed on the insulating layer 40 which serve as anode column electrodes. The second electrodes 66a to 690 may be formed by the so-called printing method just as the first electrodes are formed. One end of the second electrodes 66a to 690 are respectively connected to the corresponding connecting leads 26a to 29a through the apertures 46a to 49c formed in the insulating layer 40. For example, the

second electrodes

66a, 66b and 66c are connected to the connecting lead 26a through the apertures 46a, 46b and 460. Y

After the second electrodes 66a to 690 are formed as mentioned above, a second insulating layer 70 is' formed over the second electrodes 66a to 69c, as shown in FIG. 5. The second insulating layer 70 may be formed by the same method as the first insulating layer 40 is formed. Further, the second insulating layer 70 has bored therethrough a plurality of apertures 80,81 and 82. The apertures 80,81 and 82 are bored at the positions corresponding to those of the

apertures

51, 52 and 53 of the first insulating layer 40. r

In the next step, as shown in FIG. 6, a plurality of, third electrodes, in this case three electrodes a, 90b and 90 are formed on the second insulating layer 70 separately from one another at the positions corresponding to three indicator units. The

third electrodes

90a, 90b and 90c respectively act as selecting electrodes for changing over the indicatorunits. Further, the third electrodes 90a,. 90b and 900 may be formed by the same method as the first and second electrodes are formed, for example, by the printing method. The

I

third electrodes

90a, 90b and 90c are then electrically connected through the apertures 80,81 and 82 of the second insulating layer 70 and through the

aperture

51, 52 and 53 of the first insulating layer 40 to the connecting

leads

30a, 31a and 32a. The material of the respective electrodes, may for, example, be silver paint which has the property to adhere to glass effectively.

As shown in FIGS. 7 and 8, a plurality of apertures are bored from the third electrodes to the upper surface of the first electrodes at all the positions where all the first, second and third electrodes are opposed to one another. All the apertures 95 may be formed by, for example, a so-called sand-blast method with a mask made of rubber-resin, or etching method with a mask made of photo-resist such as KPR (trade name). In use of the etching method, an etchant such as nitric acid water may be employed for the electrodes of silver paint (for about 20 minutes) while hydrofluoric acid nitric acid water may be employed (for several minutes) for the electrodes on a glass layer of low melting point. After the mask is removed, a nickel layer may be formed by, for example, an electro-plating method on the parts of the electrodes where the electrodes are exposed.

After the indicator units 11 to 13 are thus formed on the base plate 2, the cover plate 3 is attached to the base plate 2 as shown in FIG. 9 by suitable cement or other means so as to form a sealed chamber between the base plate 2 and cover plate 3 which encloses the indicator units 11 to 13 therein. The leads of the electrodes for external connection have portions which extend beyond the cover plate 3 on the base plate 2, so that electrical connection of this invention can be'made easily.

The base plate 2 is formed with an opening (not shown) to which an exhaust pipe (not shown) may be connected so as to evacuate the space between the cover plate 3 and the base plate 2. After evacuation of the space, a suitable ionizable gas may be inserted through such openingof the base plate 2 into the space between the cover plate 3 and the base plate 2 including apertures 95 formed in the indication units 11 to 13 and thereafter the opening of the base plate 2 may be sealed up by a suitable seal in a conventional manner.

To assure that the first electrodes 21 to 25 produce glow over their points, it is desirable to age or activate the electrodes. FIG. shows apparatus to accomplished this purpose. The device illustrated therein allows current to be sequentially applied among the first, second and third electrodes and each of the indicator electrodes of each indicator unit to repeat the discharge of current among them on a time-divisional ba- SIS.

The cathode electrodes 21 through are connected to a cathode driver 101, the anode electrodes 66a through 690 are connected to an anode driver 102, and the selecting electrodes a through 90c are connected to a selecting driver 103 respectively. The cathode driver 101 supplies suitable positive voltage of, for example, 80 volts, to the electrodes 21 through 25, while is controlled with a character signal produced in a decoder 104, so that a selected cathode electrode is ground. The device illustrated in FIG. 10 further provides an oscillator producing a clock pulse of high frequency to be supplied to a counter circuit 106. The output signals of the counter circuit 106 are suppliedto the

driver circuits

102 and 103 and also to the decoder 104 respectively, to control the latter with a predetermined relationship.

The anode driver 102 always supplies a predetermined voltage of, for example, 100 volts to the anode electrodes 66a to 69v and also applies sequentially a voltage higher than the former, for example, a voltage of 180 volts in a time divisional manner, which is illustrated in FIGS. 11D to 116. The selecting driver 103 always applies to the selecting electrodes 90a to 900 a predetermined voltage of, for example, 70 volts and also a voltage higher than the former, for example, a voltage of 145 volts to the same in a time divisional manner, which is illustrated in FIGS. 11A to 11C. The time period, during which the high voltage is applied, for example, to the selecting electrode 90a of the indication unit 11, corresponds one cycle (which includes four pulses) of pulse voltage applied to the anodes 66a to 69a of the indication unit 11.

Assuming that high voltage is applied to the first selecting electrode 90a from the selecting driver 103 as shown in FIG. 11A and the cathode electrodes 21 to 25 are made to be zero voltage by the output of the decoder 104 through the cathode driver 101 as shown in FIG. 11H to 1 1L and also that the anode electrodes 66a to 69a are sequentially supplied with high voltage pulses through the anode driver 102. During the time only when the pulse of high voltage shown in FIG. 11D 5 is applied to -the anode electrode 66a, electric discharge is established between the anode electrode 66a and the cathode electrodes 21 to 25 to display the figure 1. At this time, although the anode electrodes 66b and 660 are also supplied with the same voltage, no electric discharges occur between the anode electrodes 66b and 66c and the cathode electrodes 21 to 25 due to the fact that corresponding selecting electrodes 90b and 900 are both kept at low voltage. Next, when the selecting electrode 90b for the indication unit 12 is supplied with the pulse of high voltage as shownin FIG. 118, the anode electrode 66b of the indication unit 12 is supplied with the pulse of high voltage as shown in FIG. 11D, and at the same time the cathode electrodes 21 to 25 are made to be zero voltage as shown in FIGS. 11H to 11L, electric discharge occurs between the anode electrode 66b and the cathode electrodes 21 to 25 to display FIG. I. In this case, the

anode electrodes

66a and 660 of the

other indication units

11 and 13 are supplied with the same high voltage, but no electric discharge occurs between the

anodes

66a and 66c and the cathode electrodes 21 to 25 due to the fact that the corresponding selecting

electrodes

90a and 900 are kept at low voltage. For this reason, only the indication unit 12 displays the FIG. l. Thus, in this invention the indication of the indicator units 11 to l3 is-determined in accordance with the relationship among the voltages applied to the anode electrodes 66a to 69c, the cathode electrodes 21 to 25 and the selecting electrodes 90a to 900. The reason why the indication of the indicator units isdetermined by the voltages applied to the selecting electrodes may be considered that. when a selecting electrode is supplied with a certain voltage, the potential gradient between the corresponding anode and cathode is increased with space charges present near or oppose the selecting electrode.

FIG. 12 is a graph showing the relationship between the voltage applied to the selecting electrode (in abscissa) and the voltage applied to the anode (in ordinate), which is based upon our experiments. In the graph, reference character A shows a curve for the case of the display device of 200 torr. As apparent from the curve A, when the voltage applied to the selecting electrode is 70 volts, electric discharge is at first initiated by applying voltage of 177 volts to the anode, but when a voltage of volts is applied to the selecting electrode, the electric discharge is initiated by applying a voltage of 155 volts to the anode.

Reference character B in the figure shows a curve for the case of the displaydevice of 300 torr. As apparent from the curve B, when a voltage of 70 volts is applied to the selecting electrode, the electric discharge initiates at the state that a voltage of 168 volts is applied to the anode, but when a voltage of 140 volts is applied to the selecting electrode, the electric discharge occurs at the state where a voltage of volts is applied to the anode.

As apparent from the above description, with the invention, the electric discharge can be initiated by applying a pulsating voltage to the selecting electrode even if the anode is supplied with relatively low voltage and also the electric discharge can be controlled by controlling the voltage applied to the selecting electrode.

A second example of the invention will be described with reference to FIGS. 13 to 15. In the figures, reference numeral 201 designates an insulating base plate made of, for example, glass. As shown in FIG. 13, a plurality of first electrodes 202 are formed on one surface of the base plate 201 in parallel with one another and in the horizontal direction in the figures. Next, an insulating layer 210 is formed on the first electrodes 202 except the marginal portion of the latter as shown in FIG. 14. At the following stage, a plurality of second electrodes 220 are formed on the insulating layer 210 in parallel with one another and to intersect the first electrodes 202 at substantially right angles thereto. The method of making and the material of the first and secondelectrodes 202 and 220 and the insulating layer 210 may be substantially same as that of the above mentioned example.

As shown in FIG. 14, a plurality of apertures 230 are respectively formed through the second electrodes 220 and the insulating layer 210 at the positions where the first and second electrodes 202 and 220 are overlapped by, for example, a so-called sand-blast method or etching method. As seen from FIG. 15, each of the apertures 230 reaches the upper surface of the first electrodes 202 through the second electrodes 220 and the insulating layer 210. After the apertures 23 are bored as described above, a nickel layer (not shown) may be formed on the second and first electrodes 220 and 202, if desired. The base plate 201 with the electrode portions mentioned above is covered by the transparent envelope (not shown) in an air tight manner. In the space between the base plate 201 and the envelope a suitable ionizable gas is sealed in a conventional manner to form a display device of this invention.

The method of making the display device mentioned above in connection with FIGS. 13 to 15 is same as that of the foregoing example and with this method the apertures 230 for electric discharge can be formed at the positions where the first and second electrodes 202 and 220 intersect with one another without any positional shift. Accordingly, it will be understood that the display device thus manufactured performs a clear indication.

If the first and second electrodes 202 and 220 are increased in number, a large size indicator device can be provided for displaying not only desired letters and figures but also other patterns by selectively applying a predetermined voltage to predetermined ones of said first and second electrodes 202 and 220.

Another example of this invention will be described with reference to FIGS. 16, 17 and 18. In the figures, reference numeral 301 designates an insulating base plate made of, for example, glass. On the base plate 301 a plurality of first electrodes or cathode electrodes 310 with thickness of about l-l3 microns are formed in a predetermined pattern by, for example, printing of ,silver paint and baking. The first electrodes 310 may be formed by, for example, etching with a photoresist mask. Next, an insulating layer 302 made of, for example, glass of low melting point, is formed on the base plate 301 and the first electrodes 310 to a thickness of about 50 microns by printing and then baking. A plurality of second electrodes or grid electrodes 320 are then formed on the glass layer 302 with a predeter mined pattern by the method same to that of the first electrodes 310. Thereafter, a glass layer 303 made of glass similar to that of the layer 302 is formed on the glass layer 302 and on the grid electrodes 320 to thickness of about 50 microns. A plurality of third electrodes or anode electrodes 330 are formed on the glass layer 303 with a predetermined pattern by the same method for the cathode electrodes 310.

As shown in FIG. 17, a plurality apertures 304 of, for example, cone-shape are formed through the third electrodes 330 to the glass layer 302 to partially expose the cathode electrodes 310 at the positions where the cathode electrodes 310, grid electrodes 320 and the anode electrodes 330 are opposed to one anothenThe method of making such apertures 304 is substantially same to those described in connection with the foregoing examples. A nickel layer may be formed to cover the exposed portions of the

electrodes

310, 320, and 330, if desired. Thereafter, a transparent cover 305 made of transparent glass is attached to the base plate 301 to form a tube 306 enclosing therein the

electrodes

310, 320 and 330. The tube 306 is evacuated and is filled with an inert gas to complete a display device.

The

electrodes

310, 320 and 330 intersect with one another as shown in FIG. 18. Due to provision of the apertures 304 with the shape mentioned above, at each aperture 304, the cathode electrodes 310 appear of disc-shape, while the grid electrodes 320 and the anode electrodes 330 are both of ring-shape. All the

electrodes

310, 320 and 330 are of elongated strip-shape except at the apertures 304.

In the foregoing example, it is possible to form both the grid electrodes 320 and the cathode electrodes 310 on the base plate 301.

With the display device as shown in FIGS. '16 to 18, if the cathode electrodes 310 are kept at zero potential, if the anode electrodes 330 are supplied with a positive voltage and if the voltage applied to the grid electrodes 320 is varied within the range from negative to positive, the electric discharges between the cathode electrodes 310 and the anode electrodes 330 are controlled. While the electric discharge occurs the cathode portions of the cathode electrodes 310 opposingthe apertures 304 appear brilliant as display electrodes.

In all the examples described above, the first to third electrodes and the first to second insulating layers are respectively formed on the base plate, and the apertures are formed at the intersecting points of the first to third electrodes from the uppermost (third) electrodes to the upper surface of the first (cathode) electrodesby etching or the sand-blast method. The same display device, however, can be manufactured by the method which will hereinbelow be described with reference to FIGS. 19 to 20.

A first insulating layer 402, which is formed of, for example, glass and on'a first electrode 403 formed on a base plate 401 made of, for example, glass, has been previously bored therethrough an opening 402a, by, for example, the printing method. Similarly, a second electrode 404 is formed on the first insulating layer 402. At the same time, an opening 404a is bored through the second electrodes 404. A second insulating layer 405 made of, for example, glass which has been previously bored therethrough an opening 405a is formed on the second electrode 404 and then a third electrode 406 which has been previously bored therethrough an opening 406a is formed on the former by the printing method.

As seen from FIG. 19, there may occur the case that all the

opening

402a, 404a, 405a and 406a are not aligned with one another correctly upon forming of the electrodes and insulating layers by the printing method due to the shift of patterns used therein. For this reason, a predetermined aperture 410 is bored through the third electrode 406 to the first insulating layer 402 at the position including the

openings

402a, 404a, 405a, and 406a by the sand-blast method or etching method as shown in FIG. 19 by the dotted line. As a result of this, all the openings are aligned with one another to be the opening 410 even if they are not aligned at first. The display device which includes such display device proper can display letters, figures and so on clearly.

In the first example of this invention, it is possible to place the selecting electrode plates between the cathode and anode electrodes. Further, it is also possible to form apertures through all of the electrodes.

It will be well understood that many variations and modifications could be effected without departing from the scope of the novel concepts of this invention.

We claim as our invention:

1. A display device comprising: a plurality of indicator units formed on a plate of an insulating material, said plurality of indicator units comprising a plurality of first electrode segments located in a first plane and arranged parallel to each other in a first direction, a plurality of second electrode segments arranged overlying said first electrode segments and located in a second plane above said first plane and arranged parallel to each other and extending in a direction so they cross said first electrode segments to form a number of crossing points, and a plurality of selecting electrode plate segments located in a third plane above said second plane and each electrode plate segment overlying different crossing point regions of said first and second electrode segments such that each electrode plate segment defines a differnet one of said indicator units, an insulating layer between said first and second electrode segments, a second insulating layer between said second electrodes and said selecting electrode plates, there being only one selecting electrode plate for each of said indicating units, a pluraltiy of first connecting leads each connected to one of said first electrode segments of said indicator units, a plurality of second connecting leads each connected to one of said second electrode segments of each of said indicator units, a plurality of third connecting leads each connected to one of said selecting electrode plates, a plurality of apertures formed in said first and second insulating layers and in at least said second and third electrodes, a transparent cover mounted on said plate of insulating material on the side of said indicator units to form an envelope, an ionizable gas sealed in said envelope, first circuit means for applying pulse voltage to the respective first electrode segments in a time divisional manner, second circuit means for applying pulse voltage to the respective second electrode segments in a time divisional manner, and third circuit means for applying pulse voltage to the respective selecting electrode plates in a time divisional sequential manner such that only one electrode plate is energized at a time, whereby a glow discharge indication occurs at those crossing points of said energized electrode plate where a pulsed second electrode segment overlies a pulsed first electrode segment to illuminate the particular indicator unit associated with said one electrode plate such that the energized crossing points are illuminated to produce the desired intelligence.

2. A display device according to claim 1 in which said apertures are conical.

3. A display device according to claim 1 in which each of said first electrode segments are composed of a plurality of disc shaped sections interconnected by elongated stringers, a disc shape segment being located beneath each aperture said second electrode segments being composed of ring shaped sections connected by elongated stringers, there being one ring shaped section above each of said disc shaped sections, and said third electrode segments being composed of ring shaped sections connected by elongated stringers, said ring shaped sections of said third electrode segments being larger in diameter than said ring shaped sections of said second electrode segments.

Claims

2. A display device according to claim 1 in which said apertures are conical.