US 3509408 A
Description (OCR text may contain errors)
G. E. HOLZ April 2s, 1970 DISPLAY PANEL WITH SEPARATE SIGNAL AND SUSTAINER ELECTRODES Filed Dec. l5, 1967 IO 60 l SUSTAINING SIGNAL fIOO R. n OZ N TL R ma o vH l m. I E
United States Patent O U.S. Cl. 313-201 7 Claims ABSTRACT OF THE DISCLOSURE The disclosure is of a display panel including a plurality of small gas-filled cells and comprising a sandwich of top and bottom plates, between which is disposed a thin plate which carries rows and columns of apertures which, in the completed device, are filled with an ionizable gas which can glow when properly energized. The top plate carries electrodes in operative relation with rows of cells, and the bottom plate carries electrodes in operative relation with columns of cells. These row and column electrodes are used to carry information signals, and, in addition, auxiliary electrodes are provided on the top and bottom plates for carrying sustaining signals.
BACKGROUND OF THE INVENTION Devices of the type contemplated by the present invention have memory; that is, Vafter cells have been fired and caused to glow by means of firing signals, the fired state can be sustained by means of sustaining signals of smaller amplitude than the ring signals. In the past, these devices have used row electrodes and column electrodes spaced from each other across the cells and oriented at 90 to each other for applying both the firing signals -and the sustaining signals. This is a generally satisfactory arrangement; however, this applicant has discovered that greater flexibility and utility can be achieved by the devices described below.
SUMMARY OF THE INVENTION Briefly, a device embodying the invention includes a plurality of cells with row electrodes and column electrodes connected across the cells and having separate sustaining electrodes in operative relation therewith.
DESCRIPTION OF THE DRAWING In the drawing:
FIG. 1 is a sectional elevational view of a display panel embodying the invention;
FIG. 2 is a plan view of the device of FIG. 1; and
FIG. 3 is a sectional elevational view of a modification of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT The principles of the invention are applicable to single gas-filled cells, but the following description relates to a display panel including many cells.
A display panel 10 embodying the invention includes a sandwich of glass plates including a top plate 20, a bottom plate 30, and an intermediate plate 40 having a plurality of apertures or cells 50 arranged in rows and columns (FIG. 2) and comprising the light-producing cells of the display. In panel 10, each column of cells 50 is provided with a common column electrode 60 positioned on the upper surface of top plate 20, and each row of cells is provided with a common row electrode 70 positioned on the lower surface of bottom plate 30. The row and column electrodes are oriented at right angles Mice to each other and are of suicient length so that they are accessible at an edge of the panel and can thus be readily connected to external circuitry. A glass layer or film 76 covers electrodes 60, and a similar glass film 78 covers electrodes 70.
According to the invention, a metal plate 80 to be used as a sustainer electrode is positioned on the top surface of glass film 76, and a similar electrode is positioned on the bottom surface of the glass film 78. The cells 50 are shaped so that electrodes 80 and 90 can see each other through the cells for proper operation.
In order for the cells 50 to be visible when they tire, electrode 80 is transparent completely or merely in the area over each cell. A transparent electrode may be made, for example, of a thin film of a metal such as gold.
The display panel 10 is operated in a circuit (FIGS. l and 2) which includes signal input sources, signal decoders and the like represented by blocks which receive signal information and apply firing signals to the column and row electrodes 60 and 70, respectively, with selected cells receiving the proper information signals to cause them to light and thereby to represent the registering of intelligence. An A.C. sustaining signal supplied by source is capacitively coupled between the sustainer electrode plates 80 and 90. With this arrangement, the information signals can be removed after cells have been ignited, and the ignited state can be sustained by the sustaining signal from source 110.
A panel 10 which comprises a modification of the invention is shown in FIG. 3 and includes the apertured center plate 40 with cell apertures 50, top plate 20, bottom plate 30, row electrodes 70 on bottom plate 30, insulating layer 78, and the lower sustainer plate 90. In this panel 10', the column electrodes 60 are provided as above; however, in this case, the upper separate sustainer electrode comprises a column electrode 80', like the column electrodes `60, for each column of cells, with all of the sustainer electrodes 80 connected together in common to sustaining signal source 110.
It is to be noted again that the principles of the invention can be embodied in a device which comprises just one cell as well as in a panel including many cells.
In practicing the present invention, the cells 50 are filled with an ionizable, light-producing gas such as neon, argon, etc., with mixtures of these gases, or with mixtures of these gases and other gases such as nitrogen and helium. A mixture of about 96% neon and about 4% nitrogen at a pressure of a few hundred mm. Hg is particularly suitable for the intended purpose.
With respect to a typical circuit for operating the device of the invention, the cells can be fired with signals of about 800 volts peak, and the fired state can be maintained with an alternating sustaining signal of about 700 volts peak at a frequency of about 500 kc.
One important advantage of the electrode arrangement described above is that the two electrical functions, that is, the application of information signals and the application of sustaining signals, are separated, and thus better control of each can be achieved. In addition, lower drive power is required, and a favorably low impedance in the sustainer circuit can be utilized.
What is claimed is:
1. A display panel including a center sheet of insulating material having a plurality of gas-filled cells arrayed in rows and columns and having a top surface and a bottom surface,
a rst glass plate covering said top surface of said sheet and comprising a closure for one end of each of said cells, said first glass plate having a first free outer surface remote from said cells,
a second glass plate covering said bottom surface of said sheet and comprising a closure for the other end of each of said cells, said second glass plate having a second free outer surface remote from said cells, said first and second glass plates serving to retain said gas within said cells,
first electrodes on said first free outer surface of said first glass plate, each first electrode being aligned with a row of cells,
second electrodes on said second free outer surface of. said second glass plate, each second electrode being aligned with a column of cells whereby each cell has at least two electrodes, a portion of a first electrode anda portion of a second electrode, in operative relation therewith, each two electrodes being capacitively coupled to each other through said first and second glass plates and the associated cell, and
third and fourth electrode means capacitively coupled across said cells and insulated from said first and second electrodes,
said cells being adapted to be fired and caused to glow by the application of firing potentials to a rst electrode and a second electrode associated with selected cells to be fired, the firing of said selected cells forming charges on the walls of the fired cells, the glow in the selected fired cells being adapted to be sustained by means of sustaining signals applied to said third and fourth electrode means.
2. The panel defined in claim 1 wherein said third and r ourth electrode means comprise large-area metal plates.
3. The panel defined in claim 1 wherein said third elecrode means comprises a large-area metal plate, and said fourth electrode means comprises an electrode insulated from but associated with each said first electrode.
4. The panel defined in claim 1 wherein said gas comprises a mixture of about 96% neon and about 4% nitrogen.
5. The panel defined in claim 1 and including a third glass plate covering said rst electrodes and having a third free outer surface,
a fourth glass plate covering said second electrodes and having a fourth free outer surface,
said third and fourth electrode means engaging said outer surfaces of said third and fourth glass plates, respectively.
6. The panel defined in claim 5 wherein said third and fourth electrode means comprise large-area metal plates.
7. The panel defined in claim 5 wherein said fourth electrode means comprises a large-area metal plate, and said third electrode means comprises a plurality of electrodes, each associated with a row of said cells.
References Cited UNITED STATES PATENTS 2,967,965 1/196-1 Schwartz 315-169 X 3,042,823 7/1962 Willard 315-169 X 3,334,269 8/1967 LHeureuX 315-169 X RAYMOND F. HOSSFELD, Primary Examiner U.S. Cl. X.R.