HK1069480A - Luminous display and method of making same - Google Patents

Abstract

A luminous display device and method of making the same wherein a front member of transparent glass (16) is fused to the rim area (4) of a rear member (1) having a recess (8) therein and protuberances (12) projecting from the base of the recess toward the front member, the protuberances being closely spaced with respect to each other and the front member to provide passages (14) between the protuberances and a light discharge chamber (20) between the front member and the recess. An opening (22) extends through the rear member communicating with the chamber. A tubular member (26) mounted on the rear member communicates with the opening for evacuating the chamber and filling it with ionizable gas. An electrode device (28) is mounted in the tubular member and is operatively connected to a power source (36) for ionizing the gas in the chamber thereby producing light discharge fingers (38,40,42,44) or streaks through the passages providing the desired display of light.

According to the method, rear member (1) is molded to form the recess and protuberances (12) integral therewith thus minimizing the number of parts of the display device.

Description

Light emitting display device and method of manufacturing the same

Technical Field

The present invention relates to a light emitting display device and a method of manufacturing the same. More particularly, the present invention relates to a gas plasma display device.

Background

It is well known that electricity will produce light when it passes through a gas. This phenomenon has been applied to display luminous symbols such as numerals, characters, figures and the like, such as neon symbols. Common gases used for this purpose are neon, argon, mercury vapor, or mixtures thereof.

U.S. patent No. 5,383,295 shows a fairly common flat panel display device in which three glass or plastic panels are fused together to form a sandwich, the outer panels are continuous flat, and the central major portion of the central panel is hollowed out to form a chamber for holding the desired inert gas. A plurality of glass frit or beads fill the interior chamber and act as a separator providing uniform spacing between the plates and the discharge channels for the discharge to the interior chamber produced by the rf voltage source fed by the electrodes. The glass beads are used to prevent collapse of the outer surface plates, particularly during manufacture of the device, and during routine use, to maintain uniform spacing between the central region and the outer plates. A tubular member is connected to the central opening of one of the two outer plates to evacuate the interior chamber and introduce an inert gas therein. An electrode is then mounted within the tubular member in contact with the gas, so that the voltage supplied by the electrode ionizes the gas, producing a finger-like light discharge that extends radially outward from a center located in the interstitial space of the glass bead, resulting in the desired display. The disclosure of this patent is incorporated herein by reference.

Us patent 5,116,632 shows a display device similar to the one described above, in which an electrode surface is provided at least at one end of the gas space for ionizing the gas, and also a logo shape, or other figures, can be formed to create a distinctive light pattern for use as a symbol, indicator or similar device.

U.S. patent 5,281,898 shows a double-sided closed cylindrical or spherical glass body defining a chamber containing an ionized gas, between which electrical discharges are generated after de-energization. The electrodes are connected to the ends of the enclosure and connected to a transformer of sufficiently high voltage to produce a visible discharge in the gas discharge region.

U.S. patent 4,403,831 shows a display device in which the edges of two panels are welded, leaving a chamber distance between them. Electrodes are placed on the back of the chamber panels and spaced glass beads are placed between the chamber panels as spacers.

A disadvantage of these prior art devices is that a considerable number of separating members are required, increasing the cost of manufacturing the material and the device as well as the cost of excess gas. Moreover, the shape and image profile generated by the light discharge are also greatly limited.

Disclosure of Invention

It is a primary object of the present invention to provide a light emitting display device that overcomes the above-mentioned disadvantages, having a minimum number of components, requiring a minimum number of gases, thereby minimizing material costs, simplifying the manufacturing process, and reducing manufacturing costs.

It is a further object of the present invention to provide a display device having a central pattern area that is capable of producing many different shapes.

It is a further object of the invention to provide a method of manufacturing a light emitting display device which is simplified relative to previous methods of manufacturing devices of the kind having a number of components.

In order to achieve the above object, the present invention provides a light emitting display device comprising: a clear glass front piece having a back surface and a flat region on at least a portion of said back surface; a rear member having front and rear sides, a recess in the front side, a plurality of projections integrally formed with said rear member and extending from said recess in the rear member toward said front side, and a flat peripheral edge surrounding said recess, said front surface being joined in a fused seal with a flat area on the rear surface of said front member; a light discharge chamber between said recess and said front member, said projections being closely adjacent to one another to form an array of projections having light discharge channels extending therethrough; an ionizable gas filled in said light discharge cell; one of the front and rear members having a hole with an outer end and an inner end, the inner end communicating with the light discharge chamber; electrode means communicating with the outer end of said bore; and a power supply operatively connected to said electrode means for energizing the electrode means to ionize the gas in said light discharge chamber and produce a finger-like light discharge in at least a portion of the channel.

The invention also provides a manufacturing method of the display device, which comprises the following steps: providing a front piece of a transparent glass plate; molding a glass rear member having a recess in a front side thereof, the recess in the rear member having a plurality of closely spaced projections integrally formed with said rear member extending toward said front side to form light discharge channels between said spaced projections extending through gaps thereof; fusing the front side of the back part to a front part in a region surrounding the recess to form a sealed light discharge chamber between the front part and the recess and projection; at least one of the front and rear members is provided with a hole communicating with the light discharge chamber; evacuating the light discharge chamber through the aperture; filling an ionizable gas into said light discharge cell through said aperture; mounting an electrode in communication with the aperture; providing a power supply; and energizing the electrode means with said power supply to ionize the gas in the light discharge chamber to produce a finger-like light discharge in at least a portion of said channel.

The display device which achieves the above objects of the invention is comprised of two parts, the first part being planar in shape and the second part being an integral gas storage cavity or recess having a plurality of hemispherical or other shaped elements which are also integral with the second part and located within the cavity. The display device may also be curved or have other shapes, such as wavy, wherein the first and second portions, the cavity and the array of hemispherical elements therein, have the same or corresponding shape. More specifically, the two parts are made of glass or plastic and at least the first part is transparent. The second portion is preferably molded to form a cavity therein and an array of hemispherical elements projecting from the base of the cavity. The peripheral regions of the first and second portions are fused together to form an enclosed gas discharge chamber therebetween, the array of hemispherical elements projecting from the base of the cavity toward the first portion and in close proximity thereto, the gaps between the hemispherical projections providing a channel or path for directing a finger-like or striped light discharge through the device to produce a desired display. The first or second portion has an aperture having an inner end in communication with the chamber and an outer end in communication with a tubular member mounted on the first or second portion for evacuating the chamber and filling with the desired inert gas. An electrode is mounted on and supported by the tubular member and is connected to a power source for ionizing the gas to produce a light discharge through the gas in the chamber. The aperture is located off the geometric center of the chamber or array of hemispherical projections, for example, approximately halfway between the center and the edge of the chamber.

The method of manufacturing the device of the invention is such that the first part is cut or moulded from a piece of glass, the second part is moulded in a suitable mould to form a cavity having a base on one side of the glass and projections projecting from the base towards the open side of the cavity, the projections being hemispherical elements or other suitable shapes, the projections being spaced apart from each other by a small distance to form a channel or gap therebetween, the first part being placed over the cavity in contact with a peripheral region of the second part surrounding the cavity and fusing the contacting parts together to seal the cavity, a light discharge chamber being formed in the joined assembly. A through-hole is made in the first or second part, the inner end of which communicates with the chamber, the hole being offset from the middle with respect to the area covered by the chamber, preferably at half the distance between the geometric centre and the edge of the chamber. A tubular member is connected at one end to the outer end of the bore for evacuating the chamber and filling with the desired inert gas, and also for positioning the electrode mounted therein. The holes may be made during the moulding of the first or second part or may be drilled after the respective part is completed.

Drawings

The invention will now be described in more detail with reference to the accompanying drawings:

FIG. 1 is a top view of a second portion or back glass of a first embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a top view of the first portion or front glass in a first embodiment of the present invention;

FIG. 4 is a top view of the assembly of FIGS. 1, 2, 3, as seen through the transparent first portion;

FIG. 5 is a radial cross-sectional view of the assembly of the first embodiment of the present invention, taken along line 5-5 of FIG. 4;

FIG. 6 is a top view of the fitting as seen through the transparent first portion in the second embodiment;

FIG. 7 is a radial cross-sectional view of the fitting of the second embodiment of the present invention, taken along line 7-7 of FIG. 6;

FIG. 8 is a top view of the fitting as seen through the transparent first portion in the third embodiment;

FIG. 9 is a radial cross-sectional view of the fitting of the third embodiment of the present invention, taken along line 9-9 of FIG. 8;

FIG. 10 is like FIG. 5 and shows a fourth embodiment of the invention;

fig. 11 is a schematic cross-sectional view of a display device in the related art;

fig. 12 is a schematic cross-sectional view of a first embodiment of the present invention, illustrating the advantage of uniform brightness of the discharge finger.

Detailed Description

As shown in fig. 1-5, in a first embodiment of the invention, the rear glass 1 is preferably molded into a circular body, e.g., about 300mm in diameter, with a rear surface 2, a front surface 4 and an outer peripheral surface 6, using a suitable mold (not shown). The front surface 4 defines a circular recess or cavity 8 and has a peripheral radially outer surface 10 extending to the depth or bottom of the cavity. Extending upwardly from the bottom of the cavity are a number of almost semi-circular elements or projections 12, as shown in figure 2, of a lesser height than the peripheral surface 10, for reasons which will be explained further later in this description. This configuration provides interstitial channels 14 between adjacent elements 12 of the array of elements 12, as shown in fig. 1, the array of elements 12 covering the bottom of the cavity 8. The elements 12 may be pyramidal, conical, or prismatic to provide interstitial channels 14 between adjacent elements.

Fig. 3 shows a plan view of the front glass 16, which is substantially a circular flat transparent glass having substantially the same diameter as the rear glass 1. The front glass 16 is assembled with the rear glass 1 such that the peripheral region of the front glass 16 is in a close contact relationship with the surface 4 of the rear glass 1. These contact surfaces fuse together at the interface 18 to form a sealed chamber 20, as shown in fig. 5, which contains the protrusions 12 closely spaced to the inner surface of the front glass 16. The fusion temperature at the interface 18 is controlled to be just sufficient to enable fusion to occur, but not so high as to cause significant deformation or collapse of the front glass, which would affect the volume of the chamber 20. The hole 22 formed in the rear glass 1 has an inner end 24 communicating with the chamber 20. The holes 22 may be formed during the back glass molding process or may be drilled thereafter.

As shown in fig. 5, a tubular member made of glass or other suitable material is attached at one end to the outer end of the surface 2 of the rear glass 1 covering the hole 22 and the attachment point is sealed by a solder glass, which is at a temperature lower than the temperature of the glass before and after fusion. An electrode 28 having a connecting lead 34 is located within the member 26 and is attached thereto to an elongated tube 32, sealing these elements and providing tube holder support for the electrode 28 by forming a tube holder clip (stem press)30 in a manner similar to that commonly used in incandescent lamps, as described in U.S. patent No. 5,383,295, which is incorporated herein by reference. As is well known in the art, the wire 34 is made of or coated with a material having an expansion rate comparable to that of the glass 30 of the header clip, and when in a molten state, the material is pressed against the wire and hardened to form a sealing layer.

The projections 12 may be coated with any color material, such as phosphor, to produce the desired color of the display device before the front and back glasses are fused together, or the projections 12 may be uncoated. The chamber 20 is evacuated through the tube 32 using a suitable pump or corresponding device well known in the art to a desired pressure, for example about 15 microns, so that the assembled device can be finally put into use. Any type of desired gas capable of producing color or brightness may be introduced into the chamber 20 through the tube 32 and the aperture 22. The gas referred to herein may be neon, argon, mercury vapor or mixtures thereof. After the chamber is filled with gas, the tube 32 is sealed by heating or melting, for example, or by a valve arrangement (not shown) as is well known in the art. The leads are connected to a power source through appropriate switches to generate a voltage in the range of 1-7000 kilovolts or higher, and a frequency of 20,000-50,000Hz or higher. When the electrode 28 applies this high voltage, it causes the gas in the chamber 20 to ionize and produce a striped or finger-like light discharge 38, 40, 42, 44 outwardly from the aperture through the gaps between the projections 12, as shown in fig. 4. Despite the use of only one electrode, the gas can still be ionized, because there is a large enough capacitance between the ionized gas and ground (ground) to enable the ionized gas to be generated. The finger-like light discharges move randomly within the array to form the desired display device.

Although in the first embodiment the device is described as a circular structure having a diameter of about 300mm, it should be understood that the device may be of various shapes, such as star, rose, christmas tree, mickey head, etc. Furthermore, although the electrodes and evacuation and discharge devices are shown using a common aperture, the electrodes may have a separate, independent aperture.

In a second embodiment, as shown in fig. 7, the display device has two sets of rear glass members (also referred to as first and second rear members) 1, 1A stacked together to provide two separate gas discharge cells 20, 20A for simultaneously displaying different colors and/or two sets of finger-like light discharges or patterns. In this case, the front surface 4A of the second rear glass 1A and the rear surface 2 of the first rear glass 1 fuse together at the interface 46 therebetween to form a sealed bond. The hole 22A in the second rear glass communicates at its inner end with the second chamber 20A, and the second chamber 20A communicates with the outer end of the hole 22 in the first rear glass. Further, the tube 26 is attached to the rear surface 2A of the second rear glass 1A in the same manner as described above with respect to the first embodiment and fig. 5. If desired, different colored phosphors may be coated on the projections 12 and 12A to produce different colored displays. Of course, in this embodiment, for example, the first rear glass 1 is transparent so that the additional finger-like light discharges 48, 50, 52, 54 in the chamber 22A are visible, as shown in FIG. 6. The second rear glass 1A may also be transparent.

In a third embodiment of the present invention, as shown in fig. 8 and 9, the display device is curved or arcuate, except that it is the same as the first embodiment. The front glass unit 1B and the rear glass unit 16B are initially formed into the desired curved shapes by molding and then fused together, respectively, in the manner described above, or may be formed by the method described in the first embodiment, then heated, and processed into the desired curved shapes.

In a fourth embodiment, as shown in FIG. 10, the suction and inflation holes are provided on the front section 16C at 22C, rather than on the rear section 1C. Accordingly, the tubular member 26C is mounted to the outer surface of the component 16C at the outer end of the bore 22C in the same manner as described in the first embodiment.

In other embodiments of the invention, the display device may have a different shape, such as a wave shape. The fabrication and formation methods of these other embodiments are similar to those described above with respect to the third embodiment.

The schematic cross-sectional view of fig. 11 illustrates irregularities that may be produced by a striped or finger-like light 48 discharge in prior art display devices that use spherical beads 50 between a number of glass plate members 52, 54, 56 in a gas discharge chamber 58. The light discharge fingers can move up and down around the beads so that an observer can see an obstructed view of the display device, whether from above or below, in the darkest light emitted from the opposite side of the bead, thereby reducing the brightness of the display device.

The schematic cross-sectional view in fig. 12 shows that the finger-shaped light discharge 60 according to the invention can only be in the ionization chamber 20, between the projection 12 and the front part 16. Therefore, the brightness of light emitted from the display device is not changed or reduced when viewed from the front.

Although preferred embodiments of the invention have been described herein, it is to be understood that the spirit and scope of the invention is to be limited only by the claims, since certain modifications within the scope may occur to those skilled in the art.

Claims (10)

1. A light emitting display device comprising:

a clear glass front piece having a back surface and a flat region on at least a portion of said back surface;

a rear member having front and rear sides, a recess in the front side, a plurality of projections integrally formed with said rear member and extending from said recess in the rear member toward said front side, and a flat peripheral edge surrounding said recess, said front surface being joined in a fused seal with a flat area on the rear surface of said front member;

a light discharge chamber between said recess and said front member, said projections being closely adjacent to one another to form an array of projections having light discharge channels extending therethrough;

an ionizable gas filled in said light discharge cell;

one of the front and rear members having a hole with an outer end and an inner end, the inner end communicating with the light discharge chamber;

electrode means communicating with the outer end of said bore; and

a power supply operatively connected to said electrode means for energizing the electrode means for ionizing the gas in said light discharge chamber and generating a finger-like light discharge in at least a portion of the channel.

2. The light-emitting display device according to claim 1, wherein:

the projection consists of a hemispherical element extending towards the front part, close to the front part.

3. The light-emitting display device according to claim 2, wherein:

the front and rear members are at least partially curved in shape.

4. A light-emitting display device according to claim 3, wherein:

the front part and the rear part are in the shape of a section of arc on a circle.

5. A light-emitting display device according to claim 3, wherein:

the front and rear parts are wave-shaped.

6. The light emitting display device of claim 1, wherein the back member is a first back member, the aperture is on the first back member, and further comprising:

a second rear member having front and rear sides, a recess in said second rear member front side, a plurality of projections integrally formed with said second rear member and extending from said second rear member recess to said front side thereof, and a front surface surrounding a flat periphery of said channel, said front surface being joined in a fused seal with a flat area on said first rear member rear surface;

a second light discharge chamber is provided between the second rear member recess and the rear side of the first rear member, the projections in the second rear member recess being closely adjacent to one another to form a second array of projections with a light discharge channel extending therethrough;

an ionizable gas filled in the second light discharge cell;

said second rear member having an opening therein, said opening having an outer end and an inner end, said inner end being in communication with said second light discharge chamber;

the outer end of the opening on the first rear part is communicated with the second light discharge chamber;

the electrode device is communicated with the outer end of the opening of the second rear part;

and the power supply for ionizing the gas in the chambers of the first rear part and the second light discharge chamber, generating finger-like light discharges in at least some of the channels of these chambers.

7. The light emitting display device of claim 6, wherein:

the projection in the second discharge chamber is formed of a hemispherical member extending toward and closely spaced from the rear side of the first rear member.

8. The light emitting display device of claim 6, and further comprising:

at least one phosphor coated on the protrusions.

9. The light emitting display device of claim 1, and further comprising:

phosphor coated on the protrusions.

10. A method of manufacturing a display device, comprising the steps of:

providing a front piece of a transparent glass plate;

molding a glass rear member having a recess in a front side thereof, the recess in the rear member having a plurality of closely spaced projections integrally formed with said rear member and extending toward said front side to form light discharge passages through gaps between said spaced projections;

fusing the front side of the back part to the front part in a region surrounding the recess to form a sealed light discharge chamber between the front part and the recess and projection;

at least one of the front and rear members is provided with a hole communicating with the light discharge chamber;

evacuating the light discharge chamber through the aperture;

filling an ionizable gas into the light discharge cell through the aperture;

mounting an electrode in communication with the aperture;

providing a power supply; and is

Energizing the electrode means with said power supply to ionize the gas in the light discharge chamber to produce a finger-like light discharge in at least part of the channel.