Display panel

Abstract

 A display panel comprises a gas-filled envelope made up of a base plate and a face plate sealed together hermetically. The base plate is provided with a plurality of parallel, longitudinal slots, and an anode wire is disposed in each of the slots in the base plate. A metal strip is wound on the base plate and then cut to form an array of strip cathode electrodes on the base plate and oriented at an angle to the anode wires, the anodes and cathodes defining rows and columns of gas-filled cells. The face plate carries a series of parallel depressions overlying and aligned with rows of selected ones of the cells which comprise display cells, and a thin film of black insulating material is provided on the face plate covering all but the depressions in the face plate.

Description

BACKGROUND OF THE INVENTION

[0001] One type of display panel which has been made and sold commercially is known as a SELF-SCAN panel and is described in many patents including U. S. Patent No. 3,989,981, dated November 2, 1976, of James A. Ogle and George E. Holz. A version of this type of panel, known as SELF-SCAN I panel, includes two layers of cells, a lower layer of scanning cells, and an upper layer of display cells, with each display cell in operative relation with a scanning cell. Another version of this general type of panel has the scan cells and display cells coplanar, and is known as a single layer panel, or as a SELF-SCAN II panel. This type of panel is described in U. S. Patent No. 4,099,098, dated July 4, 1978, of Rudolph A. Cola. Another single layer panel is shown in U. S. Patent No. 3,631,530, dated December 28, 1971, of James A. Ogle, and the present invention represents an improvement on the'panel described in the latter patent.

DESCRIPTION OF THE DRAWINGS

[0002] 

Fig. 1 is a perspective exploded view of a display panel embodying the invention;

Fig. 2 is a sectional view of the panel of Fig. 1 shown assembled, and along the lines 2-2 in Fig. 1;

Fig. 3 is a plan view of a portion of the panel of Fig. 1;

Fig. 4 is a plan view of a portion of a panel embodying a modification of the invention; and

Fig. 5 is a perspective view of a portion of the panel illustrated in Fig. 4.

DESCRIPTION OF THE INVENTION

[0003] A SELF-SCAN display panel 10 embodying the invention includes a glass base plate 20 having a plurality of parallel longitudinal slots 30 which extend across and into the top surface 22 thereof. Anode electrodes 40S and 40D, which may be in the form of wires, are seated in the slots 30, with the anodes 40S and 40D alternating with each other. Anodes 40S are scan anodes, and anodes 40D are display anodes.

[0004] Cathode electrodes 50, in the form of narrow strips and disposed in pairs with each pair including cathodes 50A and 50B, are provided on the top surface of the base plate, with the cathodes 50A'and 50B of each pair being spaced apart to define a narrow space of about 5 mils between them,and with the cathode pairs being spaced apart from each other a suitable distance. The location at which each cathode pair crosses an anode 40 defines a column of cells; where each scan anode 40S is crossed by a cathode pair is a scan cell 56, and where each display anode 40D is crossed by a cathode pair is a display cell 58. In each column, the scan cells alternate with the display cells, and in the rows of cells, the scan cells are aligned, and the display cells are aligned.

[0005] The cathode glow produced in each column of cells appears between the cathodes 50A and 50B of each pair.

[0006] A SELF-SCAN panel also includes a reset cathode electrode 60 adjacent to the first cathode pair 50A-50B in the array of cathodes 50. The reset cathode forms a column of reset cells with the anodes 40.

[0007] A keep-alive arrangement is also provided, comprising a strip electrode 68 adjacent to the reset cathode 60 and operable with two electrodes 42 and 44 seated in slots 32 in the base plate adjacent to the first and last anodes 40. The slots 32 are only of sufficient length to permit electrodes 42 and 44 to extend under and lie in operative relation with electrode strip 68 with which they provide the desired keep-alive action.

[0008] The panel 10 includes a glass face plate 70 having an inner surface which is chemically etched to provide a plurality of parallel shallow slots or depressions 80 having a depth of about 3 to 4 mils. The slots 80 are disposed transverse to the cathodes 50 and overlie each row of display cells. This inner surface of the face plate 70 is coated with a thin layer 90 of black insulating material to provide light contast. This layer is about one mil.thick, and it covers the entire inner surface of the face plate, but not the slots or depressions 80. In this area, the layer 90 has display slots 92 which are aligned with the slots 80 in the face plate. These slots 92 in coating 90 are also aligned with the rows of display cells. The rest of the layer 90 overlies the scan cells and blocks them from being seen through the face plate 70. The face plate is hermetically sealed to the base plate and seated on the cathodes 50, 60 and electrode 68 by means of a thin glass frit sealing ring 100 which is screened on the edge of the face plate at a thickness of about 1 mil. The anode slots 30 are filled with the sealing material along the edges of the panel so that the panel is completely hermetically sealed. The panel is filled in any suitable manner with an ionizable gas such as neon or argon and a small quantity of xenon.

[0009] The above-identified patents describe the operation of two-layer (SELF-SCAN I) panels and single- layer (SELF-SCAN II) panels, and panel 10 is operated in the same way as other SELF-SCAN panels in that the columns of scan cells are turned on sequentially and then information signals are applied to selected display anodes to cause glow to transfer from the thus selected scan cell to the adjacent display cell where display glow appears. This operation is carried out continually and sequentially throughout the columns of cells of the panel to provide in the display cells an apparently stationary but changeable message.

[0010] Considering the operation of panel 10 somewhat more specifically, operating potentials are applied to keep-alive electrodes 68 and 42, 44 so that electrode 68 is an anode and electrodes 42 and 44 are glow cathodes and generate excited particles. Positive operating potential is applied to all of the scan anodes 40S, and relatively more negative potential is applied to reset cathode 60. These potentials, aided by the keep-alive particles, cause the turn-on of the column of reset cells formed by the crossing of reset cathode 60 and the scan anodes 40S. This represents the beginning of a scanning cycle.

[0011] The scanning cycle then is carried out by the application of operating potential to each of the cathode pairs 50 in turn, beginning with the cathodes adjacent to the reset cathode 60. This turns on all of the scan cells in each column of cells sequentially. With all scan cells in a column turned on, there is cathode scan glow 120S present between the cathodes 50A and 50B of the pair of cathodes above the scan anodes 40S, as illustrated in Fig. 3. This glow is not visible to a viewer because of black coating 90. As the columns of scan cells are thus turned on sequentially, information signals of sufficient magnitude are applied to selected display anodes 40D to cause glow to transfer from selected scan cells to the adjacent display cells associated with the selected anodes 40S. Thus, display glow will be present between cathodes 50A and 50B over those selected display anodes. This glow is visible in slots 80 in the face plate. This scanning operation is continued sequentially and repetitively to maintain an apparently stationary message displayed in the display cells in accordance with the input information applied to the display anodes.

[0012] It is noted that, instead of cathode pairs, each cathode 50 might comprise a single strip electrode as illustrated in Fig. 4, with all of the other panel parts being the same. In this case, when a column of scan cells is turned on, glow is present at the lower surface of the overlying cathode 50 above all of the scan anodes 40S. This scan glow is not visible to a viewer either because it is at the lower surface of each cathode; or, if it moves to the upper surface, it is not visible because of black coating 90. As the columns of scan cells are then turned on sequentially, information signals of sufficient magnitude are applied to selected display anodes 40D, ·and this causes glow to transfer from a scan slot 30 to a display slot 30 across the land between them to the portion of the top surface of the cathode overlying the selected display anode(s) 40D. This glow is visible to a viewer because it is aligned with slots 92 and 80. As above, as the scanning operation is carried out through the panel and selected display cells are caused to glow, an apparently stationary but changeable message is visible in the energized display cells.

[0013] The panels described above have the advantage that they may be built relatively easily by winding the anodes and the cathodes and then cutting the wound wire to provide the desired individual electrodes. In addition, these panels have a minimum number of parts of simple construction; and, since, in effect, all electrodes are formed on one plate, complex alignment problems are avoided. Also, since the glow cathodes are close to the face plate, the panel has a very favorable viewing angle.

Claims

1. A display panel comprising

a gas-filled envelope made up of a base plate and a face plate sealed together hermetically,

a plurality of anode electrodes disposed parallel to each other in slots in the top surface of said base plate,

cathode electrodes disposed on said top surface of said base plate and oriented at an angle to said anode wires, said anodes and cathodes defining rows and columns of gas-filled cells,

a transparent glass face plate hermetically sealed to said top surface of said base plate, said face plate having, in its top surface, parallel, shallow elongated depressions which lie transverse to said cathodes in alignment with selected ones of said anodes, and

an opaque coating on the inner surface of said face plate and having elongated openings aligned with said elongated depressions whereby cathode glow at certain portions of said cathodes are visible through said openings to a viewer looking at said face plate.

2. The panel defined in Claim 1 wherein said anodes include scan anodes and display anodes.

3. The panel defined in Claim 1 wherein said anodes include scan anodes and display anodes, and the scan anodes and display anodes alternate with each other.

4. The display panel defined in Claim 1 wherein each crossing of a cathode and said anodes defines a column of gas cells including scan cells and display cells, the scan cells and display cells alternating with each other.

5. The display panel defined in Claim 1 wherein said cathodes comprise pairs of strips spaced apart with a small space between them, and cathode glow, when it occurs, is located in said space.

6. The panel defined in Claim 1 wherein said cathodes comprise flat strips or ribbons.

7. A display panel comprising

a gas-filled envelope made up of a base plate and a glass face plate sealed together hermetically, said face plate comprising a viewing plate for said panel,

a plurality of anode wires disposed parallel to each other in slots in said base plate,

cathode electrodes disposed on said base plate and oriented at an angle to said anode wires, the crossings of said anodes and cathodes defining rows and columns of coplanar gas-filled cells, and

an opaque coating on the inner surface of said face plate, said opaque coating having transparent portions overlying selected ones of said cells to be viewed through said face plate.

8. The panel defined in Claim 7 and including depressions in the inner surface of said face plate, said depressions overlying said selected cells.

Drawing