|Publication number||US3837958 A|
|Publication date||Sep 24, 1974|
|Filing date||Jun 22, 1972|
|Priority date||Jun 29, 1971|
|Also published as||CA958759A, CA958759A1, DE2229741A1|
|Publication number||US 3837958 A, US 3837958A, US-A-3837958, US3837958 A, US3837958A|
|Inventors||Broers G, Haans P, Hornman J, Van Esdonk J|
|Original Assignee||Philips Corp|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (1), Classifications (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
p 1974 J. VAN ESDONK ETAL 3,837,958
METHOD OF MANUFACTURING A GAS DISCHARGE PANEL Filed June 22, 1972.
United States Patent US. Cl. 156-229 7 Claims ABSTRACT OF THE DISCLOSURE A gas discharge panel in which the conductors of the base plate and the upper plate are connected to said base plate and upper plate by means of an enamel.
The invention relates to a method of manufacturing a gas discharge picture display panel consisting at least of a base plate and an upper plate which consists of a light-pervious material, the base plate and the upper plate being provided with mutually insulated conductors, a number of cavities being present between the conductors of the base plate and the upper plate in which cavities gas discharges can occur when suitable potential differences are applied between the conductors. The invention furthermore relates to a gas discharge panel manufactured by said method.
The connection of a large number of generally parallel strip-like conductors to the base plate and/or the upper plate is not simple.
It is known to provide said conductors in grooves of an electrolytically oxidized aluminum plate, but this method is laborious. The conductors can be clamped in the correct position and be provided on the base plate of a mold, after which melted glass is poured over the conductors so that the latter are embedded in a glass plate, but it has been found that glass can flow between the base plate and the conductors as a result of which the effective surface of the conductors is covered with glass. Cleaning of said effective surface is very time-consuming. Pressing the conductors in a softened glass plate can also present difiiculties as a result of a mutual displacement or deformation of the conductors. In addition, the glass plate becomes less bright as a result of the strong heating.
A comparatively simple method of manufacturing gas discharge panels is obtained if, according to the invention, the conductors which are provided in the mutually correct position are secured to the base plate and/or the upper plate by means of a readily melting type of glass (enamel). The conductors can be covered on one side with a layer of enamel suspension and be laid with said side on a base plate or upper plate, after which the enamel is melted so that the conductors are secured to the plate.
The thickness of the conductors causes a number of channels to be formed which interconnect the cavities to be provided between the base plate and the upper plate.
In order to avoid undesirable discharges between the edges of the conductors facing each other, said edges may also be covered with enamel. This can be achieved in a simple manner if the enamel suspension is provided on the base plate and/or the upper plate and is melted, after which the conductors are pressed into the soft enamel. By suitable choice of the thickness of the layer of enamel suspension in relation to the thickness of the conductors and the mutual distance of the conductors, it can be achieved that the enamel covers the side edges of the conductors without the channels formed between the conductors becoming too narrow. During pressing the conductors into the enamel they are preferably also stretched.
A large number of conductors can be fixed with their ends in the correct position, but an assembly of conductors is preferably formed by photochemically etching slots in a metal plate. The pattern of the conductors or of the slots can be provided in the correct position in known manner photographically. The laborious provision at determined mutual distances and fixing of separate conductors is then superfluous.
The invention will be described in greater detail with reference to the accompanying drawing in which FIG. 1 is a sectional view of a part of a panel according to the invention, while FIGS. 2, 4 and 6 show other embodiments of a plate with conductors according to the invention, and
FIGS. 3, 5 and 7 are the corresponding cross-sectional views of FIGS. 2, 4 and 6.
In FIG. 1, 1 is a base plate, 2 a light-pervious upper plate and 3 is a perforated intermediate plate. The base plate 1 comprises a number of parallel strip-like conductors 4 and the upper plate 2 comprises a number of parallel conductors 5 extending at right angles to the direction of the conductors 4. The apertures 7 of the plate 3 are located exactly at the intersections of the conductors 4 and 5 and are filled with a suitable gas with a given pressure.
The conductors 4 are secured to the base plate 1 by means of enamel 6, the conductors 5 are secured to the upper plate 2. The spaces 8 between the conductors 4 and 5 communicate with all the cavities and enable the evaporation of the cavities 7 and the provision of the gas filling in said cavities 7. The channels formed by the spaces 8 open into a common duct, not shown, which is provided with an exhaust tube.
The conductors 4 and 5, respectively, are preferably formed by etching slots in a metal plate. The ends of the conductors 4 and 5, respectively, are then connected together by means of a rectangle consisting of four fillets. The conductors are coated on one side with an enamel suspension 5 and laid with this side on the base plate 1 and the upper plate 2, respectively. The fillets extending parallel to the conductors are removed, the fillets extending at right angles to the conductors being drawn apart by means of a drawing device, for example springs, so as to stretch the conductors. By melting the enamel suspension the conductors are then connected to the plates 1 and 2, respectively, and the fillets are removed. The plates 1, 2 and 3 with the conductors 4 and 5 are then placed one on the other and a suspension of sealing glass is provided near the edges of the plates 1, 2 and 3. The
assembly is placed in a furnace and heated so that the sealing glass joins the plates 1, 2 and 3 together in a vacuum-tight manner. By removing the fillets, the conductors are insulated from each other. The cavities 7 are then evacuated through the ducts 8 and the desirable gas is introduced into the cavities 7.
There often exists the danger of discharges between the oppositely located edges of the conductors 4 and 5, respectively. In order to avoid this, said edges may be covered with enamel.
This is preferably done by means of the method according to FIGS. 2 and 3. For that purpose, the suspension of the enamel 6 is provided on the plate 1 or 2 and the conductors 4 and 5, respectively, are pressed into the enamel after having heated and melted this. The enamel pressed away by the conductors 4 and 5, respectively, will enter into the ducts 8 between the conductors and cover the side edges of the conductors as a result of the surface tension. In order to prevent the channels from becoming too narrow, the thickness of the layer of enamel must generally be less than 25% of the thickness of the conductors. In a favourable embodiment the thickness of the enamel layer was 20 that of the conductors 100g. The width of the cathode conductors on the base plate is 0.5 mm., that of the anode conductors on the upper plate is 150 The center distance of cathode and anode conductors is the same, namely 1.2- mm. However, it is also possible to cover the side edges with enamel suspension simultaneously with the provision of the one-sided layer. However, this is not so simple as the above-mentioned method since the possibility exists that the suspension will reach the effective surface of the electrodes.
If it is desirable to incorporate a memory in the tube, the conductors 5 may be fully covered with a semi-conductive layer. The strip-like conductors 5 are then preferably replaced by the filamentary conductors 9 (FIGS. 6 and 7) which are covered with a semiconductive enamel layer 10. This enamel may also serve for the adhesion of the wires 9 to the plate 2. The wires 9 consist, for example, of chromium iron and have a diameter of 0.1 mm., the enamel layer 10 being 40p thick.
The conductors 4 and 5 are preferably manufactured by photochemically etching slots in a chromium-nickeliron sheet, 0.1 mm. thick. The additional advantage of the use of enamel for securing the conductors to base plate and upper plate is that said plates which usually consist of glass remain fully bright.
Since the conductors are heated to a lower temperature than upon pressing in a molten glass plate, the possibility of oxidation of the effective surface of the conductors is smaller, while discoloring of the glass plate as a result of dissolving oxide of the conductors does not occur. The plates may advantageously consist of window glass.
What is claimed is:
1. In the method of manufacturing a gas discharge picture display panel comprising a base plate and a lightpervious upper plate, the base plate and the upper plate comprising a number of mutually insulated conductors, a number of cavities in which gas discharge can occur when suitable potential differences are set up between the conductors being present between the conductors of the base plate and the upper plate, the step of securing the conductors provided in the correct position to the base plate and the upper plate with a readily melting enamel.
2. A method as claimed in Claim 1, wherein the conductors are coated on one side with an enamel suspension and are connected with the coated side to a base plate and upper plate by melting the enamel suspension.
3. A method as claimed in Claim 2, wherein the side edges of the conductors facing each other are also covered with enamel suspension.
4. A method as claimed in Claim 1, wherein a layer of an enamel suspension is provided on a base plate and upper plate and is heated to melt the enamel and thereafter pressing the conductors in the softened enamel layer, the enamel also covering the edges of the conductors facing each other.
5. A method as claimed in Claim 1 wherein the conductors are stretched during the securing by means of enamel.
6. A method as claimed in Claim 1 wherein the conductors are partly covered with an enamel suspension, and thereafter heating the enamel suspension to melt the same and secure the conductors to the upper and base plate respectively.
7. A method as claimed in Claim 1 wherein the base and upper plates are partly covered with an enamel suspension, the conductors are positioned on the base and upper plates respectively and thereafter heating the enamel suspension to melt the same and secure the conductors to said base and upper plates, respectively.
References Cited UNITED STATES PATENTS 3,603,837 9/1971 Turner 313218 X 3,697,793 10/1972 King 313-217 X 3,735,183 5/1973 Walters 313217 X WILLIAM A. POWELL, Primary Examiner B. J. LEITTEN, Assistant Examiner US. Cl. X.R.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US5458519 *||Nov 29, 1994||Oct 17, 1995||Samsung Electronics Co., Ltd.||Plasma display panel and the fabrication method thereof|
|U.S. Classification||156/229, 313/584, 156/299, 216/4|