Claims
- 1. In a gaseous discharge display/memory device comprising an ionizable gaseous medium in a gas chamber formed by a pair of opposed dielectric material members backed by electrode members, the electrode members behind each dielectric material surface being transversely oriented with respect to the electrode members behind the opposing dielectric material surface so as to define a plurality of discharge units, said dielectric material surfaces serving to store charges during each half-cycle of operation, the improvement wherein each dielectric member is selectively enriched with at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium and barium in an amount sufficient to provide gas discharge device operating voltages which are substantially uniform and which do not significantly change with time after a period of aging.
- 2. The invention of claim 1 wherein each dielectric member is selectively enriched with about 0.5 weight percent to about 8 weight percent of the element in the oxide state based on the total weight of the dielectric.
- 3. The invention of claim 1 wherein each dielectric member is selectively enriched with about 1 weight percent to about 4 weight percent of the element in the oxide state based on the total weight of the dielectric.
RELATED APPLICATION
This is a continuation in part of copending U.S. patent application Ser. No. 60,376, filed Aug. 3, 1970, and now abandoned.
This invention relates to novel multiple gas discharge display/memory panels which have an electrical memory and which are capable of producing a visual display or representation of data such as numerals, letters, television display, radar displays, binary words, etc. More particularly, this invention relates to novel gas discharge display/memory panels having substantially uniform operating voltages; that is, essentially stable as a function of operating time. As used herein, voltage is defined as any voltage required for operation of the panel including firing and sustaining voltages as well as any other voltages for manipulation of the discharge.
Multiple gas discharge display and/or memory panels of one particular type with which the present invention is concerned are characterized by an ionizable gaseous medium, usually a mixture of at least two gases at an appropriate gas pressure, in a thin gas chamber or space between a pair of opposed dielectric charge storage members which are backed by conductor (electrode) members, the conductor members backing each dielectric member typically being appropriately oriented so as to define a plurality of discrete gas discharge units or cells.
In some prior art panels the discharge cells are additionally defined by surrounding or confining physical structure such as apertures in perforated glass plates and the like so as to be physically isolated relative to other cells. In either case, with or without the confining physical structure, charges (electrons, ions) produced upon ionization of the elemental gas volume of a selected discharge cell, when proper alternating operating potentials are applied to selected conductors thereof, are collected upon the surfaces of the dielectric at specifically defined locations and constitute an electrical field opposing the electrical field which created them so as to terminate the discharge for the remainder of the half cycle and aid in the initiation of a discharge on a succeeding opposite half cycle of applied voltage, such charges as are stored constituting an electrical memory.
Thus, the dielectric layers prevent the passage of substantial conductive current from the conductor members to the gaseous medium and also serve as collecting surfaces for ionized gaseous medium charges (electrons, ions) during the alternate half cycles of the A.C. operating potentials, such charges collecting first on one elemental or discrete dielectric surface area and then on an opposing elemental or discrete dielectric surface area on alternate half cycles to constitute an electrical memory.
An example of a panel structure containing non-physically isolated or open discharge cells is disclosed in U.S. Letters Pat. No. 3,499,167 issued to Theodore C. Baker, et al.
An example of a panel containing physically isolated cells is disclosed in the article by D. L. Bitzer and H. G. Slottow entitled "The Plasma Display Panel -- A Digitally Addressable Display With Inherent Memory", Proceeding of the Fall Joint Computer Conference, IEEE, San Francisco, California, Nov. 1966, pages 541-547. Also reference is made to U.S. Letters Pat. No. 3,559,190.
In the construction of the panel, a continuous volume of ionizable gas is confined between a pair of dielectric surfaces backed by conductor arrays typically forming matrix elements. The cross conductor arrays may be orthogonally related (but any other configuration of conductor arrays may be used) to define a plurality of opposed pairs of charge storage areas on the surfaces of the dielectric bounding or confining the gas. Thus, for a conductor matrix having H rows and C columns the number of elemental discharge cells will be the product H .times. C and the number of elemental or discrete areas will be twice the number of such elemental discharge cells.
In addition, the panel may comprise a so-called monolithic structure in which the conductor arrays are created on a single substrate and wherein two or more arrays are separated from each other and from the gaseous medium by at least one insulating member. In such a device the gas discharge takes place not between two opposing electrodes, but between two contiguous or adjacent electrodes on the same substrate; the gas being confined between the substrate and an outer retaining wall.
It is also feasible to have a gas discharge device wherein some of the conductive or electrode members are in direct contact with the gaseous medium and the remaining electrode members are appropriately insulated from such gas, i.e., at least one insulated electrode.
In addition to the matrix configuration, the conductor arrays may be shaped otherwise. Accordingly, while the preferred conductor arrangement is of the crossed grid type as discussed herein, it is likewise apparent that where a maximal variety of two dimensional display patterns is not necessary, as where specific standardized visual shapes (e.g., numerals, letters, words, etc.) are to be formed and image resolution is not critical, the conductors may be shaped accordingly, i.e., a segmented display.
The gas is one which produces visible light or invisible radiation which stimulates a phosphor (if visual display is an objective) and a copious supply of charges (ions and electrons) during discharge.
In prior art, a wide variety of gases and gas mixtures have been utilized as the gaseous medium in a gas discharge device. Typical of such gases include CO; CO.sub.2 ; halogens; nitrogen; NH.sub.3 ; oxygen, water vapor; hydrogen; hydrocarbons; P.sub.2 O.sub.5 ; boron fluoride, acid fumes; TiCl.sub.4 ; Group VIII gases; air; H.sub.2 O.sub.2 ; vapors of sodium, mercury, thallium, cadmium, rubidium, and cesium; carbon disulfide, laughing gas; H.sub.2 S; deoxygenated air; phosphorus vapors; ;C.sub.2 H.sub.2 ; CH.sub.4 ; naphthalene vapor; anthracene; freon; ethyl alcohol; methylene bromide; heavy hydrogen; electron attaching gases; sulfur hexafluoride; tritium; radioactive gases; and the rare or inert gases.
US Referenced Citations (6)
| Number |
Name |
Date |
Kind |
|
2020727 |
Gaidies et al. |
Nov 1935 |
|
|
3189781 |
Lempert |
Jun 1965 |
|
|
3499167 |
Baker et al. |
Mar 1970 |
|
|
3559190 |
Bitzer et al. |
Jan 1971 |
|
|
3846171 |
Byrum, Jr. et al. |
Nov 1974 |
|
|
3863089 |
Ernsthausen et al. |
Jan 1975 |
|
Non-Patent Literature Citations (1)
| Entry |
| "Materials and Techniques for Electron Tubes, " by Walter H. Kohl, Reinhold Publishing Corp., New York, N.Y. 1962, pp. 24, 53, 54, 72-75. |
Continuation in Parts (1)
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Number |
Date |
Country |
| Parent |
60376 |
Aug 1970 |
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Patent Grant
4114064
