GB2054259A

GB2054259A - Gas discharge display device

Info

Publication number: GB2054259A
Application number: GB8020302A
Authority: GB
Original assignee: Modern Controls Inc
Current assignee: Modern Controls Inc
Priority date: 1979-06-27
Filing date: 1980-06-20
Publication date: 1981-02-11
Also published as: JPS569940A; FR2460016A1; DE3024071A1

Abstract

A gas discharge display device comprises a first glass plate (15) having parallel grooves (16, 17, 18) therein, each of said grooves having an electrical conductor (19) secured along a groove wall and each conductor having a dielectric overlayer (24). A second glass plate (20) has parallel grooves (21, 22) therein, each of which has an electrical conductor (21) secured along a groove wall, each conductor having a dielectric overlayer. The glass plates are sealed together with their respective grooves orthogonally positioned and facing one another, and a gaseous mixture is introduced into the grooves. At least one of the glass plates may be provided with a recess which is in communication with the grooves and which serves as a reservoir of gas. The conductors 19, 21 may be located on the bottom wall or on one or both sidewalls of the grooves. <IMAGE>

Description

SPECIFICATION Gas discharge display device This invention relates to gas discharge display devices.

Gas discharge devices utilizing flat glass panels and providing a display by means of selective ignition of a gaseous mixture sealed within the panels have electrical conductors arranged in various arrays in dielectric contact with the gaseous mixture contained within the panels. Energization of the conductors causes ignition and illumination of the gaseous mixture in the region proximate the conductors being energised. Some flat glass panels have the electrical conductors isolated from the gaseous mixture sealed within the panel by means of a dielectric material; such panels are frequently referred to as AC plasma discharge display panels, as they are typically operated by means of alternating current (AC) signals applied selectively to the various electrical conductors.

According to the present invention there is provided a gas discharge display device comprising: a first glass plate having a plurality of parallel grooves therein, each of said grooves having an electrical conductor secured along a groove wall and each conductor having a dielectric overlayer; a second glass plate having a plurality of parallel grooves therein, each of said grooves having an electrical conductor secured along a groove wall and each conductor having a dielectric overlayer; means for sealing said first and second glass plates together with their respective grooves orthogonally positioned and facing one another; and means for introducing a gaseous mixture into said grooves.

Preferably the display device includes at least one recess in at least one of said glass plates, said recess being in gas communication with said grooves.

Each of said grooves may comprise a channel having a bottom and two side walls.

In one embodiment each of said conductors further comprises a line laid along the bottom of a said channel.

In another embodiment each of said conductors further comprises a line attached to a side wall of said channel.

In a further embodiment each of said conductors further comprises a line attached to each side wall of said channel.

It is preferable that each of said grooves is .050 to .100 mm in depth, the grooves being spaced apart at substantially .375 mm spacings.

The invention is illustrated, merely by way of example, in the accompanying drawings, in which: Figure 1 shows an isometric view of one embodiment of a gas discharge device according to the present invention; Figure 2A is a plan view of the display device of Fig. 1; Figures 2B and 2C are side views of the display device of Fig. 2A; Figure 3 is a side elevation view in partial cross-section of the display device of Fig. 1; and Figure 4 shows an elevation view in partial cross-section of another embodiment of a gas discharge display panel according to the present invention.

Referring first to Fig. 1, there is shown a gas discharge display device according to the present invention having a flat glass display panel 10 composed of a first glass layer 1 5 and a second glass layer 20. Glass layers 15, 20 are tightly sealed together so as to contain a gaseous mixture. This sealing may be accomplished by any of a number of well-known techniques. The seal is preferably made around the outer edges of a contact line between plates 15, 20, as well as between all of the flat areas of the respective plates which are in contact with one another. This effectively seals the panel and rigidly maintains gas channel spacing, and thereby improves reliability of operation.Each of the glass plates 15, 20 has a plurality of parallel grooves cut therein; for example the plate 1 5 has grooves 16, 17, 18 shown in Fig. 1, and the plate 20 has grooves 21, 22. The glass plates are respectively arranged so that their grooves are orthogonal to form a matrix of intersecting grooves across the entire display panel. Each groove has secured thereto one or more electrically conductive lines, i.e. line 1 9 in the groove 1 6. These conductive lines may be secured to the grooves by means of a deposition process or other technique, so long as the electrical conductor forms a conductive line or lines along the length of the respective groove in which it is located. Overlaying each conductive line is a thin glass layer, such as layer 24 overlaying the line 19, in groove 16.

The glass layer 24 serves as a dielectric medium to isolate electrically the line 1 9 from a direct contact with the gas in groove 1 6 when the display panel operates.

Fig. 2A shows the matrix of grooves and conductive lines found in the respective glass plates. Grooves 16, 17, 18, 21, 22 are shown by way of example. The display panel 10 may have one or more reservoirs for containing a supply of gaseous mixture, such as a reservoir 26 and/or a reservoir 28. The reservoir 26 comprises a hollowed-out region in the glass plate 15, preferably along an edge of the glass plate and in communication with each of the grooves of the glass plate 1 5. Similarly, the reservoir 28 is a hollowedout region in the glass plate 20, also preferably along an edge of the glass plate and in gas communication with the grooves of the glass plate 20.Either or both reservoirs serve the purpose of providing a supply of gaseous mixture to make up any leakage which might occur during the lifetime of the display panel and thus to ensure that the panel remains operational even though a small leakage occurs. The reservoirs 26, 28 are typically filled with a gaseous mixture including neon and other similar gases, the precise gaseous mixture being a function of the overall design parameters of the display panel. Fig. 2B shows a plan view of the display panel, illustrading plates 15, 20 and the respective gas reservoirs 26, 28. Similarly, Fig. 2C illustrates another side view of the panel showing the glass plates and the reservoirs.

Fig. 3 illustrates the display panel 10 in greater detail. Illustrated are the relative dimensions of the respective grooves and conductor lines. The grooves are preferably all of the same depth D2, normally .025 to .100 mm. The width of the grooves D3 is preferably in the range of .075 to .125 mm. The conductor line spacing D1 is preferably about .250 to .375 mm. The conductor lines themselves, for example the conductor line 19, are made as thin as is practicable with existing deposition technology, and the thickness of the glass layers such as the glass layer 24 are preferably of the same order of magnitude as the conductor line thickness. A display panel according to the present invention will have a plurality of gas channels, i.e. channel 32 in groove 16, which will be uniformly filled with a gas mixture.Each of the channels such as channel 32 will intersect with a plurality of similar channels in the other glass plate, such as channel 42 in the glass plate 20. The total spacing between intersecting conductor lines will be approximately 2D2, and the application of a suitable voltage to these intersecting conductor lines will cause the gaseous mixture at the intersecting point, of the channels 32, 42, for example, to become ignited and provide a visual display.

Fig. 4 illustrates an alternative embodiment of a gas discharge display device according to the present invention wherein conductor lines are located on one or more side walls of a groove. The same or different relative dimensions may be utilized for this embodiment in order to achieve the same operational results.

Conductor lines 1 9a and 19b, either or both of which may be attached along a groove side wall, are covered with a thin glass layer 30 which serves as a dielectric medium preventing direct contact between the conductor lines and the gaseous mixture in the groove 1 6.

The grooves in the glass plate 20 may be similarly constructed, or may be constructed according to Fig. 3. The construction of Fig. 4 is particularly adaptable for improving the visible gaseous ignition in the region intermediate the respective conductor lines, if the side wall conductors are placed in the glass plate 1 5. In this instance, a line of sight visibility is provided by splitting the conductor lines, or by placing a single conductor line along a side wall, so that the observer can directly see the gaseous ignition and thus avoid the shielding effects of a conductor line.

In operation, electrical conductors which extend through the display panel and to its exterior are selectively energized along respective orthogonal directions at voltage levels such that the additive effects of voltages appearing on two intersecting conductors are sufficient to ignite the gas therebetween. Because of the physical characteristics of the display panel, and the utilization of a dielectric separation, the actual gaseous mixture ignition at any point appears for only a brief interval of time, and if the apparent lighted ignition region is desired to be maintained the intersecting conductors must be repeatedly energized with AC signals. The number of such ignition points is determined by the size of the display panel itself, and various ignition patterns can be selectively and controllably developed through proper conductor energization.

Whenever an intersecting point which has previously been ignited is desired to be extinguished, electrical de-energization signals are applied to the conductors intersecting that point, according to known techniques, thereby removing the voltage potential necessary for sustaining ignition.

Claims

1. A gas discharge display device comprising: a first glass plate having a plurality of parallel grooves therein, each of said grooves having an electrical conductor secured along a groove wall and each conductor having a dielectric overlayer; a second glass plate having a plurality of parallel grooves therein, each of said grooves having an electrical conductor secured along a groove wall and each conductor having a dielectric overlayer; means for sealing said first and second glass plates together with their respective grooves orthogonally positioned and facing one another; and means for introducing a gaseous mixture into said grooves.

2. A display device as claimed in claim 1 including at least one recess in at least one of said glass plates, said recess being in gas communication with said grooves.

3. A display device as claimed in claim 1 or 2 in which each of said grooves comprises a channel having a bottom and two side walls.

4. A display device as claimed in claim 3 in which each of said conductors further comprises a line laid along the bottom of a said channel.

5. A display device as claimed in claim 3 in which each of said conductors further comprises a line attached to a side wall of said channel.

6. A display device as claimed in claim 3 in which each of said conductors further com prises a line attached to each side wall of said channel.

7. A display device as claimed in any preceding claim in which each of said grooves is .050 to .100 mm in depth, the grooves being spaced apart at substantially .375 mm spacings.

8. A gas discharge display device substantially as herein described with reference to and as shown in the accompanying drawings.

9. In a flat panel gas display of the type having a gaseous medium excited into ignition by electrical energization of conductor lines dielectrically separated from the gaseous medium, the improvement in panel construction comprising (a) a first glass plate having a plurality of parallel grooves therein, each of said grooves having an electrical conductor secured along a groove wall and each conductor having a dielectric overlayer; (b) a second glass plate having a plurality of parallel grooves therein, each of said grooves having an electrical conductor secured along a groove wall and each conductor having a dielectric overlayer; (c) means for sealing said first and second glass plate together with their respective grooves orthogonally positioned and facing one another, and (d) means for introducing a gaseous mixture into said grooves.