This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application entitled PLASMA DISPLAY PANEL filed with the Korean Industrial Property Office on 17 Dec. 2002 and there duly assigned Serial No. 2002-0080804, and an application entitled PLASMA DISPLAY PANEL filed with the Korean Industrial Property Office on Jan. 15, 2003 and there duly assigned Serial No. 2003-0002682.
1. Technical Field
The present invention relates to a plasma display panel and, more particularly, to barrier ribs of a plasma display panel.
2. Related Art
A plasma display panel (PDP) typically includes barrier ribs that define discharge cells. The two main types of barrier ribs are closed barrier ribs and open barrier ribs. The open barrier ribs are generally formed in a stripe configuration. Since discharge cells formed between such stripe-type barrier ribs are in communication (i.e., the discharge cells between each pair of adjacent barrier ribs are in communication), exhaust of the PDP and sealing of discharge gas within the PDP are relatively easily performed during manufacture.
With the closed barrier ribs, on the other hand, the discharge cells are not in communication. That is, the barrier ribs are formed into individual units having a quadrilateral, hexagonal, or other shape. With the closed barrier ribs, the discharge cells are separately formed for each pixel, and phosphor material is formed over all inner surfaces of barrier ribs that form each pixel.
In the first PDPs that utilized such closed barrier ribs, a gap formed between a distal end of the barrier ribs and the substrate opposing the substrate on which the barrier ribs are formed was used as an exhaust path. The gap was formed by adjusting the height of the barrier ribs or by forming depressions at predetermined locations of distal end areas of the barrier ribs. However, because of the minimal size of the gap, the resulting exhaust resistance necessitated the use of a significant amount of time to exhaust the PDP. This reduced overall manufacturing efficiency.
Various configurations have been disclosed to overcome these problems. For example, Japanese Laid-Open Patent No. Heisei 4-274141 discloses a structure in which open stripe-type barrier ribs and closed lattice-type barrier ribs are combined to reduce exhaust resistance. However, with such a combinational structure, the process of forming each barrier rib on the substrate during PDP manufacture is complicated. With this structure, productivity is reduced to such an extent that mass production is made difficult.
Japanese Laid-Open Patent No. Heisei 2002-83545 discloses a PDP in which closed barrier ribs are formed using a material that has a heat shrink property. The barrier ribs are formed having areas of lesser height that function as exhaust paths to thereby form a mesh-type structure of the exhaust paths. Although it is claimed that such a barrier rib structure reduces exhaust resistance during the exhaust process, in practice, there is a limited number of paths through which exhaust may occur as a result of the mesh configuration. This may result in insufficient exhaust of the PDP.
The present invention provides a plasma display panel including barrier ribs that maximize exhaust efficiency.
More particularly, the present invention provides a plasma display panel including barrier ribs that enable improvements in brightness through the efficient use of discharge cells.
In one embodiment, the present invention provides a plasma display panel including a first substrate, a second substrate mounted opposing the first substrate with a predetermined gap therebetween to thereby form a vacuum assembly, and barrier ribs formed between the first substrate and the second substrate, the barrier ribs defining discharge cells. Radial exhaust paths are formed in the barrier ribs for each of the discharge cells.
The discharge cells are formed in a closed configuration by the barrier ribs, and the discharge cells are arranged in a lattice pattern or a delta pattern.
In another embodiment, the present invention is a plasma display panel including a first substrate, a second substrate mounted opposing the first substrate with a predetermined gap therebetween to thereby form a vacuum assembly, and barrier ribs formed on the second substrate and extending a predetermined distance in a direction toward the first substrate, the barrier ribs defining discharge cells. A plan view of the barrier ribs is such that, if imaginary lines are formed bisecting distal end surfaces of the barrier ribs, the imaginary lines form a plurality of multilateral shapes that encompass each of the discharge cells to thereby form the discharge cells into the multilateral shapes. Also, if a radius of a first inscribed circle drawn in areas of the barrier ribs corresponding to corner portions of the multilateral shapes of the discharge cells is R, and a radius of a second inscribed circle drawn in areas corresponding to predetermined points between the corner portions of the multilateral shapes of the discharge cells is r, the following condition is satisfied:
R>r.
Alternatively, the barrier ribs may be formed so as to satisfy the following condition:
R>2r.
The barrier ribs are made of a material that has a heat shrink property, and widths of the distal end surfaces of the barrier ribs vary, in a continuous manner or in stages, along a direction in which the barrier ribs are formed.
Further, exhaust paths are formed in the barrier ribs such that one of the exhaust paths is formed in areas of the barrier ribs corresponding to each side of the multilateral discharge cells. The exhaust paths are formed in the distal ends of the barrier ribs.
The plasma display panel further includes sub exhaust paths formed in areas of the barrier ribs where corner portions of the multilateral shapes of the discharge cells converge. The sub exhaust paths are realized by exhaust grooves formed in the barrier ribs.
In another embodiment, the present invention is a plasma display panel including a first substrate, a second substrate mounted opposing the first substrate with a predetermined gap therebetween to thereby form a vacuum assembly, and barrier ribs formed on the second substrate and extending a predetermined distance in a direction toward the first substrate, the barrier ribs defining discharge cells. A plan view of the barrier ribs is such that, if imaginary lines are formed bisecting distal end surfaces of the barrier ribs, the imaginary lines form a plurality of multilateral shapes that encompass each of the discharge cells to thereby form the discharge cells into the multilateral shapes.
Also, the height of the barrier ribs, measured from where they are formed on the second substrate to the distal end of the same, is greater at areas corresponding to corner portions of the multilateral shapes of the discharge cells than at areas between the corner portions of the multilateral shapes of the discharge cells.
The height of the barrier ribs is at a maximum at areas corresponding to the corner portions of the multilateral shapes of the discharge cells, and the height of the barrier ribs is at a minimum at predetermined points between the corner portions of the multilateral shapes of the discharge cells.
A width of the distal ends of the barrier ribs at areas corresponding to the corner portions of the multilateral shapes of the discharge cells is greater than the width of the distal ends of the barrier ribs at areas between the corner portions of the multilateral shapes of the discharge cells.
Further, the heights of the barrier ribs vary in a continuous manner starting from where the heights are maximum and decreasing until reaching the minimum heights.
The present invention is more specifically described in the following paragraphs by reference to the drawings attached only by way of example. Other advantages and features will become apparent from following description and from the appended claims.
A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:
Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
With reference to the drawings, the plasma display panel (PDP) according to the first embodiment of the present invention includes a first substrate 10 and a second substrate 12 opposing one another with a predetermined gap therebetween. A vacuum assembly is formed by the combination of the first substrate 10 and the second substrate 12.
Address electrodes 14 are formed in a predetermined pattern (e.g., a stripe pattern) and at predetermined intervals on the second substrate 12. A first dielectric layer 16 is formed on the second substrate 12 and covers the address electrodes 14. Further, barrier ribs 18 are formed on the first dielectric layer 16 and in a predetermined pattern to define a plurality of discharge cells 17.
In the first embodiment, the barrier ribs 18 are made of a glass material having a low melting point. Regarding a plan view formation of the barrier ribs 18, with reference to
The barrier ribs 18 include row sections 18a extending in a direction substantially perpendicular to the direction in which the address electrodes 14 are formed, and column sections 18b extending in a direction substantially parallel to the direction in which the address electrodes 14 are formed. Areas where the row sections 18a and the column sections 18b intersect, that is, areas of the barrier ribs 18 between four adjacent discharge cells 17, occupy a greater space than other areas of the barrier ribs 18. The formation of the barrier ribs 18, and, in particular, the relative widths of the barrier ribs 18, will be described in greater detail below.
As an example, areas of the barrier ribs 18 between four adjacent discharge cells 17 are the greatest among all areas of the barrier ribs 18, while areas of the barrier ribs 18 corresponding to centers of long sides and short sides of adjacent discharge cells 17 are the smallest among all areas of the barrier ribs 18. In particular, a radius R of a first inscribed circle C1 (see
With reference to
With this configuration, gaps of predetermined dimensions are formed between the first substrate 10 and the distal ends of the row sections 18a and the column sections 18b of the barrier ribs 18 by the difference in the heights H1 and H2. Preferably, the difference in the heights H1 and H2 is between 5 and 10 μm. These gaps function as exhaust paths P through which air inside the PDP travels when forming a vacuum in the same during manufacture. As a result, radial paths P are provided for each of the discharge cells 17. In the first embodiment, four exhaust paths P are provided for each discharge cell 17.
The barrier ribs 18 are formed by a sandblast process, which is commonly used in the manufacture of PDPs. If a minimum width of the barrier ribs 18 that can be formed using the sandblast process is m, the radius r of the second inscribed circle C2 described above satisfies the condition:
2r<m.
Further, with reference to
The barrier ribs 18 structured as described above are produced according to the following manufacturing method of the present invention.
First, in a state where the address electrodes 14 and the first dielectric layer 16 are formed on the second substrate 12, a barrier rib material layer of a predetermined thickness is realized through a paste, which is formed by uniformly mixing a vehicle and a glass powder having a low melting point, and the barrier rib material layer is formed on the first dielectric layer 16 using a screen printing method or a laminate method. The glass powder of a low melting point may be made, for example, of a material containing 50˜60 wt % of Pbo, 5˜10 wt % of B2O3, 10˜20 wt % of SiO2, 15˜25 wt % of Al2O2, and 5% or less of CaO.
Following the drying of the barrier rib material layer, a photosensitive dry film is formed or a resist material is deposited. Then, using a photolithography process that includes exposure and development, a cut mask is formed in a lattice pattern corresponding to the desired shape of barrier ribs. The dimensions of the mask pattern are set to be greater than the desired dimensions of the barrier ribs since thermal contraction of the barrier rib material layer occurs.
Next, using a sandblast process, non-masked portions of the barrier rib material layer are removed until the dielectric layer is exposed. Heating and baking are then performed to thereby complete the formation of the barrier ribs.
The cut mask has a pattern corresponding to the various shapes of the barrier ribs 18 as described above.
Red, green, and blue phosphor layers 20R, 20G, and 20B (see
Further, formed on a surface of the first substrate 10, opposing the second substrate 12, are discharge sustain electrodes 22 that include common electrodes 22a, scanning electrodes 22b, and bus electrodes 22c formed on each of the common electrodes 22a and the scanning electrodes 22b The common electrodes 22a and the scanning electrodes 22b are made of a transparent material, such as indium tin oxide (ITO), and the bus electrodes 22c are made of a conductive material, such as silver (Ag) or gold (Au).
The discharge sustain electrodes 22 are formed in a direction substantially perpendicular to the direction in which the address electrodes 14 are formed. A second dielectric layer 24 is formed on the first substrate 10 covering the discharge sustain electrodes 22, and a protective layer 26 made of MgO is formed over the second dielectric layer 24. The protective layer 26 acts to protect the discharge sustain electrodes 22, and functions also to aid discharge by emitting secondary electrons.
In the PDP having the closed barrier rib structure as described above, there are provided radial exhaust paths P for each of the discharge cells 17 such that exhaust efficiency is significantly improved over the prior art.
In the third embodiment, areas of the barrier ribs 38 between any three, mutually adjacent discharge cells 37 occupy the largest area and have the greatest height when compared to other areas of the barrier ribs 38, that is, main sections 38a of the barrier ribs 38. This results in the formation of exhaust paths in the main sections 38a of the barrier ribs 38. Since there is a larger number of exhaust paths for each of the discharge cells 37 than in the first embodiment, an even greater improvement in exhaust efficiency is realized.
The basic configuration of
In
The PDP of the fourth embodiment of the present invention utilizes the same basic structure as the PDP of the first embodiment. However, sub exhaust paths 40 are formed at areas where the row sections 18a and the column sections 18b intersect, that is, at areas of the barrier ribs 18 between four adjacent discharge cells 17.
The sub exhaust paths 40 are formed to enable communication between adjacent discharge cells 17 to thereby improve the exhaust process. With reference also to
With the PDP of the fourth embodiment, in addition to the radial exhaust paths formed by the particular configuration of the row sections 18a and the column sections 18b of the barrier ribs 18 as described with reference to the first embodiment, the sub exhaust paths 40 act to even further improve exhaust efficiency.
While the present invention has been illustrated by the description of embodiment thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the special details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the sprit and scope of the general inventive concept.
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10-2003-0002682 | Jan 2003 | KR | national |
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