BACKGROUND OF THE INVENTION A considerably difficult engineering problem exists with regards to sealing flat panel video displays. The need to join elements of different mass, geometry or material creates construction problems unaddressed by current manufacturing processes. The present state of the art is highly economically inefficient due to material constraints and structural design requirements.

Current flat panel displays consist of a top plate connected to side plates that are, in turn, connected to a bottom plate. Alternatively, a molded top plate may be used, either with or without the side plates. In either embodiment, a frit material is placed between the various pieces at the contact points to serve as the sealing means once a heating process is applied.

The use of a frit material for sealing glass is commonly known.

However, a critical feature under current design practices is that the frit must be applied very evenly across the contact surfaces, bringing rise to one of the major challenges of the current display panel structure-proper alignment of the plates. The frit, in order to be effective, must be aligned properly with the pieces to be fused together, and the pieces must be properly located on the display if the manufacture is to be proper. Under current design practices, the relative contact surfaces are flat and are prone to shifting during the manufacturing process. Any shifting or misalignment of the parts will yield a substandard or ineffective display panel that is prone to premature failure.

Another significant problem with the current state of the art is the surface conditions of the respective plates. Any defect on the contact surfaces of the pieces is a potential pressure balancing, or moisture admitting port. In either case, the display may again be rendered inoperable or otherwise defective.

Still further, the relative flatness of the connecting surfaces is critical to proper sealing of the display. Should either surface be inclined relative to the other, the result is a drastic reduction in the sealing contact surface. This, of course, increases the odds of seal failure by the decrease in the effective seal surface area. Also, similar to leaning a chair back from its normal upright position, the inclination may result in unwanted relative movement between the contact surfaces.

Another significant problem with the existing display panels is the creation of excessive residual internal stresses caused in part by the

vacuum. More specifically, when varying materials or materials of varying mass are connected together, heated and then cooled, the differing rates of expansion create internal stresses. This especially occurs when the grid or wire associated with the internal active matrix, passes through the frit sealing to the outside environment. The grid or wire, generally metallic in nature, conducts heat quickly, and thereby expands and contracts faster than the surrounding material, leaving space around the wire port. The space prevents the display panel from having a vacuum in the inner space and allows circuitry-damaging pollutants into the display.

Another problem affecting sealing of display panels is the number and volume of information lines passing through the sealing means. More specifically, the characteristics of material best suited for conduction of signals through a display are not generally characteristics best suited for the sealing of the display. Achieving and maintaining an adequate seal around the information lines is difficult due to contrasting material properties between the seal material and information line material. This problem is compounded in displays requiring a relatively large volume or number of information transfer lines.

Another limitation of the present state of the art is the material choices-chiefly, the type of glass that may be used in the displays.

Currently, due to design limitations, the choices of glass material are limited by the constraints of the manufacturing process.

SUMMARY OF THE INVENTION A sealing structure on a display panel forms a vacuum chamber between a top panel and a bottom panel. The sealing structure includes at

least one of a V-groove, U-groove or W-groove sealing structures. The sealing structure may further includes a layer of indium tin oxide or layers of alternating materials, including a conductor and a non-conductor.

In accordance with further aspects of the invention, the top panel is a flat or a molded panel.

In accordance with other aspects of the invention, the sealing structure includes one or more of a frit material, a plating material, a metallic drop, and/or a washer.

In accordance with still further aspects of the invention, the sealing structure includes an epoxy seal.

In accordance with still other aspects of the invention, the sealing structure includes a getter structure.

As will be readily appreciated from the foregoing summary, the invention provides a new and improved system for aligning and sealing flat panel displays.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of the present invention is described in detail below with reference to the following drawings: FIGURE 1 is a cross-sectional view of an embodiment of the prior art flat panel display; FIGURE 2 is a front view of the device in FIGURE 1; FIGURE 3 is a cross-sectional view of an embodiment of the prior art molded top panel display; FIGURE 4 is a front view of the device in FIGURE 3;

FIGURE 5 is a cross-sectional view of a V-groove sealing embodiment for a flat panel display; FIGURE 6 is a front view of the device in FIGURE 5; FIGURE 7 is a cross-sectional view of a V-groove sealing embodiment for a molded top panel display; FIGURE 8 is a front view of the device in FIGURE 7; FIGURE 9 is a side view of the V-groove seal embodiment; FIGURE 10 is a side view of a U-groove seal embodiment; and FIGURE 11 is side view of a W-groove seal embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIGURES 1 and 2 illustrate an embodiment of the prior art. More specifically, FIGURES 1 and 2 illustrate a cross-sectional and front view, respectively, of current, flat panel display construction.

The prior art flat panel construction, such as panel 2, typically uses a top glass 4, a bottom glass 8 and a plurality of side glass pieces 6. The side glass pieces 6 are arranged around the periphery and placed between the top glass 4 and the bottom glass 8, thereby creating an inner space 20.

The side glass pieces 6 are typically rectangular in shape and are cut in length to extend substantially entirely around the periphery of the display.

The top glass 4, side glass 6 and bottom glass 8 are fused together by a frit material 18-a glassy material that goes into solution at a relatively low temperature. Care must be taken to apply the frit material 18 to all contact surfaces on the glass pieces. When heated, the frit

"wets"the contact surfaces of the glass pieces that form an airtight seal around the inner space 20 that is a vacuum.

Within the inner space 20 are posts 16, designed to support an electrical grid or wire 10. As FIGURES 1 and 2 illustrate, the electrical grid or wire 10 originates outside of the panel display 2, passes through the frit material 18 into the inner space 20, over the posts 16, through the frit material 18 and back outside of the panel display 2. The respective terminal ends of the grid or wire 10 may be attached to pins 12, wherein the pins 12 and the panel display 2 are mounted on a carrier 14. The pins 12 and carrier 14 shown in FIGURES 1 and 2 are for illustrative purposes only, and are not intended to limit the structure outside of the panel display.

FIGURES 3 and 4 are also illustrative of another embodiment of the prior art. However, this embodiment illustrates a type of molded panel display 30 wherein a molded top glass 32 replaces the flat top glass 4 disclosed above. This embodiment is illustrative of the small, alphanumeric displays produced by the Japanese. Further, the display is shown as not utilizing the above mentioned side glass pieces 6, rather the molded top glass 32 is sealed directly to the bottom glass 8 via the frit material 18 method disclosed above. However, it is understood that this embodiment may also utilize side glass pieces 6 in the construction process. Further, the carrier 14 and pins 12 are not illustrated, yet are considered to be applicable to this disclosure.

FIGURES 5 and 6 illustrate a cross-sectional and front view, respectively, of an embodiment of this invention-a V-groove flat panel

display 50. Of specific interest, and what defines the heart of this invention, is the innovative sealing means located on the contact surfaces of the V-groove flat panel display 50. Located on the contact surfaces of the V-groove top plate 52 and the V-groove bottom plate 54, respectively, are V-groove projections 58 and V-groove recesses 56. The respective projections 58 and recesses 56 are generally centrally located on the flange portion 68 of the top plate 52 and bottom plate 54. Further, the relationship between the size of the flange portion 68 relative to the geometry of projections 58 and recesses is a function of material choice and sealing requirements. The projections 58 and recesses 56 cooperatively work to solve the above-mentioned problems. More specifically, the V-groove sealing arrangement solves the problems of alignment, irregular surface conditions, flatness of contact points and internal stresses in the display.

The above-mentioned alignment problems are overcome by the inter-relation of the V-groove projections 58 and recesses 56. The construction of this panel display 50 forces the V-groove top plate 52 into a positive and constant relation with the V-groove bottom plate 54.

Consequently, regardless of the specific manufacturing process used, the relation between the top plate 52 and the bottom plate 54 is a constant.

This constant relation between the plates, unlike the prior art, prevents improper application of additional sealing means such as misaligned frit material 18, or other additional sealing means described in more detail below.

An additional benefit of the V-groove flat panel display 50 is that the V-groove compensates for any irregular surface conditions. More specifically, it may be desirable to design the V-groove projection 58 and the V-groove recession 56 such that the majority of the connecting loading bares on the tip region of the V, thereby locating the bulk of the sealing properties deep within the V-groove recession 56. As such, the irregular surface conditions are largely rendered moot.

Another problem, similar to surface condition, regards the relative flatness of the connecting surfaces. As discussed above, when the relative plates are brought together, considerable atmospheric pressure-related forces are acting on the plates. Due to the hollow inner space 20, and the contact surfaces being located around the periphery of the display 50, a deflection occurs around the base of the contact surfaces, thereby weakening the sealed joint. The present invention eliminates this problem in the same way the surface condition problem is eliminated. The present invention is constructed to perform most of the sealing deep in the V- groove recess 56. Therefore, deflections at the contact surfaces are largely inconsequential.

Finally, the V-groove design eliminates the resultant build-up of internal stresses in the panel display 50-a common problem in the prior art designs. As discussed above, the use of materials having different Coefficients of Thermal Expansion (CTE), or materials of substantially different masses, yields different heating and cooling rates or times, which in turn generates stresses in the display panel 50. However, the present invention reduces the effective area of the contact area, thereby

eliminating the problem of excessive internal stresses. Thus, the present invention permits the use of various materials or masses as long as the mass and material at the contact surfaces are within an allowable CTE range from one another.

Another feature disclosed initially in FIGURE 5 is the getter feature. More specifically, a getter projection 62 combined with a getter recession 64 and getter material 66. The purpose of the getter feature is to provide a system or substance that binds gases to its surface, which will help prevent out-gassing of the display panel.

FIGURES 7 and 8 show cross-sectional and side views of another embodiment of the instant invention-a molded V-groove panel display 70. As seen in FIGURE 7, a molded V-groove top plate 72 is combined with a typical V-groove bottom plate 54. Similar to the disclosure of FIGURES 5 and 6, this embodiment comprises V-groove recesses 56 and projections 58 located on the contact surface of the flange portion 68 of the respective plates. Also disclosed is the getter structure, including the getter projections 62, recesses 64 and material 66. As illustrated by this disclosure, the V-groove sealing design does not limit the shape of the display panel. Rather, the simplicity and reliability of the sealing design permits greater flexibility in the design of the display panel. As the critical sealing features are limited to the V-groove area, a designer is free to shape the panel as they choose. It is to be noted that, as illustrated, this embodiment may also incorporate the gettering structure as disclosed earlier.

FIGURE 9 is an isolated illustration of the various embodiments of the V-groove seal as depicted in FIGURES 5-8. As can be seen from this illustration, the pressure differential between the interior and exterior of the display in conjunction with the limited contact surface area of the sealing structure serves as the sealing medium. However, also anticipated as additional sealing structure-an ordinary frit seal may be used with this sealing geometry. Additionally, the contact surfaces of the V-groove structure are capable of being sputtered with a surface coating of a conductive layer, such as indium tin oxide (ITO) 94. The ITO 94 serves as the signal transfer medium between electrical components at the interior and the exterior of the display 30. Further, the V-groove projection 58 and the V-groove recess 56 are capable of being plated with a plating material 98, either inclusively or exclusively with the ITO 94 sputtered surfaces. The plating material 98 is, for example, nickel, silver, or other such material having similar properties.

Also, shown in FIGURE 9 is a metallic drop 92, which may be used separately or in combination with the plating material98 or ITO 94 sputter. The metallic drop 92 is generally a piece of malleable metal, such as gold, aluminum, or the like, placed in the bottom of the V-groove recess 56. The pressure exerted on the respective plates is transferred to the metallic drop 92, thereby deforming the metallic drop 92 and forming a positive seal between the plates 52,54. One possible combination is sputtered ITO 94 and silver plating coupled with a gold metallic drop 92.

However, any other metallic material combination having similar

properties may be used for plating material 98 or the metallic drop 92 without exceeding the scope of this invention.

In an alternative embodiment, a washer 82 is used in place of the metallic drop 92. Because the V-groove focuses the contact pressure on the point of the V, very high deformation forces are created at that point, and deformation of the washer to fill the groove is achieved. As with the metallic drop 92, the washer 82 must have certain physical properties in order for it to function properly as a sealing device. More specifically, the washer 82 must be tough enough to withstand the pressure exerted and the geometric deformation it will undergo. As well, the washer 82 must be pliable or malleable enough to form an adequate seal along the entire seam. The washer 82 is constructed from either a conducting or non- conducting material that is not of an organic nature. An example washer 82 is made of indium. And like the metallic drop 92, the washer may be used in conjunction with plating material 94 of the V-groove projections 58 and recesses 56.

In still another embodiment, an epoxy seal or bead 78 is used in conjunction with the other sealing devices of this invention. The epoxy seal 78 is generally applied when the bottom plate 54 is extended past the top plate 52 as illustrated in FIGURES 9-11. Generally, the epoxy seal is extended around the entire perimeter of the joining section and serves to further prevent any outgassing into the display. Again, the epoxy must be of a variety to withstand the manufacturing process, i. e. temperature and pressure variants. An example of such an epoxy is a silver epoxy.

In an embodiment of the present invention, V-groove projections 58 and recesses 56 do not perfectly mate absent additional sealing materials such as drop 92, washer 82 or bead 78 as described above.

Instead, V-groove projections 58 having an angle for the"V"smaller than that of the corresponding angle of V-groove recesses 56. In this manner the forces upon top plate 52 are more tightly concentrated on the tip of the "V", providing tighter sealing when using a sealing material.

FIGURES 10 and 11 illustrate alternative embodiments of the V- groove sealing system. However, it is to be understood that each embodiment employs any or all of the same sealing means used with the V-groove design. FIGURE 10 shows a U-groove design and FIGURE 11 illustrates a W-groove design. As can be seen in FIGURE 10, the top plate has a U-groove projection and the bottom plating material 90 has a U-groove recess. FIGURE 11 shows the W-groove design, complete with plating 94, epoxy sealing 78, and a washer 82. In practice, the W-groove works like a succession of V-grooves, trading off single-point higher pressure sealing for a slightly lower pressure, but redundant sealing points. Both alternative embodiments employ the same principles as the V-groove design and are considered alternative equivalents. Additionally, one or more of the ITO 94 sputter, the plating 98, the epoxy sealing 78, the metallic drop 92 and the washer 82 are also included in the U-groove and W-groove designs.

It is to further be recognized that a variety of materials may be used in the construction of the display panels. Since the geometry and construction of the sealing area permits the use of a low temperature frit,

soda lime glass is no longer the only material choice. For example, a boro silicate, tempered or complex glass may be used. Also, as long as the CTEs of the materials at the critical surfaces are within tolerable ranges of one another (approximately 5%), it is conceivable that materials such as ceramics and steels may be used in the manufacture of the display panels.

While the preferred embodiment of the invention has been illustrated and described, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment.

Instead, the invention should be determined entirely by reference to the claims that follow.