1. Field of the Invention
The present invention relates to a plasma display apparatus, and more particularly, to the structures of electrodes capable of improving efficiencies of sustain discharge and address discharge in discharge cells arranged in delta.
2. Description of the Background Art
In a plasma display apparatus, discharge cells are formed between a rear surface substrate on which barrier ribs are formed and a front surface substrate that faces the rear surface substrate and vacuum ultraviolet (UV) rays generated when inert gases in the discharge cells are discharged by a high frequency voltage emit light from a phosphor to realize an image.
First, the discharge cell is formed by a plurality of barrier ribs 24 with which a discharge space is partitioned off on a rear surface substrate 18 that faces a front surface substrate 10.
A data electrode X is arranged on the rear surface substrate 18 and a scan electrode Y and a sustain electrode Z are arranged on the front surface substrate 10 to make a pair. The rear surface substrate 18 illustrated in
A lower dielectric layer 22 for accumulating wall charges is formed on the rear surface substrate 18 where the data electrode X is formed.
The barrier ribs 24 are arranged on the dielectric layer 22 to form a discharge space between the barrier ribs and to prevent the UV rays and visible rays generated by discharge from leaking to adjacent discharge cells. The surfaces of the dielectric layer 22 and the barrier ribs 24 are coated with a phosphor 26.
Since inert gases are implanted into the discharge space, the phosphor 26 is excited by the UV rays generated when the gases are discharged to generate one visible ray among red, green, and blue visible rays.
The scan electrode Y and the sustain electrode Z arranged on the front surface substrate 10 are composed of transparent electrodes 12Y and 12Z and bus electrodes 13Y and 13Z to intersect the data electrode X. Also, a dielectric layer 14 and a protective layer 16 that cover the scan electrode Y and the sustain electrode Z are formed.
After the discharge cell of such a structure is selected by facing discharge between the data electrode X and the scan electrode Y, discharge is sustained by surface discharge between the scan electrode Y and the sustain electrode Z so that the visible rays are emitted.
The scan electrode Y and the sustain electrode Z are composed of the transparent electrodes 12Y and 12Z and the bus electrodes 13Y and 13Z whose width is smaller than the width of the transparent electrodes 12Y and 12Z and each of which is formed at one edge of each of the transparent electrodes 12Y and 12Z.
The square delta barrier ribs 24 are composed of first barrier ribs 24a that are horizontally formed and second barrier ribs 24b formed in the same direction as the data electrode X. Since the directions in which the square delta barrier ribs 24 are contracted by thermal stress vary at the intersections between the first and second barrier ribs 24a and 24b during the annealing process performed at 550 to 600° C. as illustrated in
The hexagonal delta barrier ribs illustrated in
Accordingly, an object of the present invention is to solve at least the problems and disadvantages of the background art.
It is an object of the present invention to provide a plasma display apparatus including three or more cells arranged on a rear surface substrate to be partitioned off by barrier ribs in delta, data electrodes arranged under the cells, pairs of sustain electrodes arranged on a front surface substrate attached to the rear surface substrate to at least partially intersect the barrier ribs, and at least one extension parts extended from the pairs of sustain electrodes to the insides of the cells to face each other and having at least one depressed parts.
The barrier ribs includes first barrier ribs that at least partially overlap the pairs of sustain electrodes and second barrier ribs that at least partially overlap the data electrodes and the first barrier ribs.
The at least one depressed parts face each other in the cells. A distance between the extension parts is 60 to 180 μm.
Also, the data electrodes at least partially overlap the at least one extension parts and/or depressed parts in the cells.
There is also provided a plasma display apparatus including three or more cells arranged on a rear surface substrate to be partitioned off by barrier ribs in delta, data electrodes arranged under the cells and having wide parts and narrow parts, pairs of sustain electrodes arranged on a front surface substrate attached to the rear surface substrate to at least partially intersect the barrier ribs, and at least one extension parts extended from the pairs of sustain electrodes to the insides of the cells to face each other.
The barrier ribs include first barrier ribs that at least partially overlap the pairs of sustain electrodes and second barrier ribs that at least partially overlap the data electrodes and the first barrier ribs.
Also, the wide parts are formed in the cells that are discharge spaces and the narrow parts at least partially overlap second barrier ribs that partition off the cells and that are non-discharge spaces.
Also, the data electrodes at least partially overlap the at least one extension parts and/or depressed parts in the cells.
There is also provided a plasma display apparatus including three or more cells arranged on a rear surface substrate to be partitioned off by barrier ribs in delta, data electrodes arranged under the cells and having wide parts and narrow parts, pairs of sustain electrodes arranged on a front surface substrate attached to the rear surface substrate to at least partially intersect the barrier ribs, and at least one extension parts extended from the pairs of sustain electrodes to the insides of the cells to face each other and having at least one depressed parts.
The barrier ribs include first barrier ribs that at least partially overlap the pairs of sustain electrodes and second barrier ribs that at least partially overlap the data electrodes and the first barrier ribs.
A distance between the extension parts is 60 to 180 μm. Extension parts in the adjacent cells are intercepted from each other. The at least one depressed parts formed in the extension parts face each other.
The wide parts are formed in the cells that are discharge spaces and the narrow parts at least partially overlap second barrier ribs that partition off the cells and that are non-discharge spaces.
The at least one extension parts at least partially overlap the wide parts in the cells. The at least one depressed parts at least partially overlap the wide parts.
The width of the wide parts is 75% to 150% of the width of the extension parts. The width of the narrow parts is 5% to 75% of the width of the extension parts. At least one hole is formed in the narrow part.
The present invention will be described in detail with reference to the following drawings in which like numerals refer to like elements.
Delta discharge cells of a plasma display panel (PDP) according to preferred embodiments of the present invention and the structures of the electrodes of the discharge cells will be described in a more detailed manner with reference to the drawings.
Preferred embodiments of the delta discharge cells of the PDP according to the present invention and the structures of the electrodes of the discharge cells may be plural and are not limited to the embodiments described in the specification.
The plasma display apparatuses according to the first to fourth embodiments have a delta structure in which the discharge cells adjacent to each other in the up and down direction form a pixel.
That is, the PDP according to the present invention forms the R, G, and B discharge cells arranged in delta. According to the present specification, the discharge cells are hexagonal. However, the discharge cells may be square discharge cells, pentagonal discharge cells, other polyhedral discharge cells, curved discharge cells, or amorphous discharge cells.
The plasma display apparatus according to the present invention includes data electrodes X and pairs of sustain electrodes Y and Z that intersect the data electrodes X. At this time, first barrier ribs 54a at least partially overlap the pairs of sustain electrodes Y and Z and second barrier ribs 54b at least partially overlap the data electrodes X and the first barrier ribs 54a.
The scan electrode Y and the sustain electrode Z of the pair of sustain electrodes are composed of transparent electrodes 42Y and 42Z and bus electrodes 43Y and 43Z whose width is smaller than the width of the transparent electrodes 42Y and 42Z. The bus electrodes 43Y and 43Z are formed along the first barrier ribs 54a that overlap the pairs of sustain electrodes Y and Z at one edge of each of the transparent electrodes 42Y and 42Z.
The transparent electrodes 42Y and 42Z are commonly formed of indium tin oxide (ITO) on a front surface substrate. That is, the transparent electrodes 42Y and 42Z are connected to the bus electrodes 43Y and 43Z as illustrated in
Therefore, the data electrodes X are formed to cross the centers of the hexagonal discharge cells as illustrated in
The bus electrodes 43Y and 43Z reduce drop in voltage caused by the transparent electrodes 42Y and 42Z having high resistance and supply voltage signals to the transparent electrodes 42Y and 42Z. Therefore, the bus electrodes 43Y and 43Z are connected to the connection parts 42b of the transparent electrodes 42Y and 42Z in order to supply driving signals to the transparent electrodes 42Y and 42Z of the discharge cells.
Also, the bus electrodes 43Y and 43Z are formed of at least one of Ag, Cu, and Cr to be connected to the transparent electrodes 42Y and 42Z and to partially overlap the first barrier ribs 54a.
An upper dielectric layer 44 and a protective layer 46 are formed on the front surface substrate 40 where the pairs of sustain electrodes Y and Z are formed. Wall charges generated during plasma discharge are accumulated on the upper dielectric layer 44. The protective layer 46 prevents the upper dielectric layer 44 from being damaged by sputtering generated during plasma discharge and improves the emission efficiency of secondary electrons.
A lower dielectric layer 52 on which wall charges are accumulated is formed on a rear surface substrate 48 where the data electrodes X are formed. Barrier ribs 54 that prevent ultraviolet (UV) rays and visible rays generated by discharge from leaking to adjacent discharge cells are arranged on the lower dielectric layer 52. The surfaces of the lower dielectric layer 52 and the barrier ribs 54 are coated with a phosphor 56.
The phosphor 56 is excited by the UV rays generated during plasma discharge to generate one visible ray among red, green, and blue visible rays. Inert gases for gas discharge are implanted into discharge spaces provided between the front and rear surface substrates 40 and 48 and the barrier ribs 54.
As described above, since the first barrier ribs 54a overlap the bus electrodes 43Y and 43Z in the plasma display apparatus according to the first embodiment, the discharge spaces to which the visible rays are emitted are not intercepted by the bus electrodes 43Y and 43Z. Also, since the connection parts 42b of the transparent electrodes 42Y and 42Z are connected to the bus electrodes 43Y and 43Z and the extension parts 42a1 and 42a2 of the transparent electrodes 42Y and 42Z protrude to the insides of the discharge cells in the plasma display apparatus according to the first embodiment, discharge efficiency is improved.
As illustrated in
First and second depressed parts 42d1 and 42d2 are formed on the facing surfaces of the first and second extension parts 42c1 and 42c2 so that a distance between the center C of the first extension part 42c1 and the center C of the second extension part 42c2 is different from a distance between the edge E of the first extension part 42c1 and the edge E of the second extension part 42c2.
That is, since the first and second depressed parts 42d1 and 42d2 are formed in the centers C of the first and second extension parts 42c1 and 42c2 as illustrated in
The length of the long gap between the transparent electrodes formed by the first and second depressed parts 42d1 and 42d2 is within 60 to 180 μm based on a resolution VGA level.
As described above, in the plasma display apparatus according to the second embodiment, since the distance between the centers C of the extension parts 42c1 and 42c2 of the transparent electrodes to which a voltage that generates discharge is applied is larger than the distance between the edges E of the extension parts 42c1 and 42c2 of the transparent electrodes to which a voltage that generates discharge is applied due to the depressed parts 42d1 and 42d2, it is possible to secure a larger positive column region in which discharge starts than in the first embodiment where the distance between the centers C of the extension parts 42c1 and 42c2 is equal to the distance between the edges E of the extension parts 42c1 and 42c2. Therefore, it is possible to improve contrast.
As illustrated in
The pair of sustain electrodes arranged on the front surface substrate are composed of the scan electrode Y and the sustain electrode Z. The scan electrode Y and the sustain electrode Z are composed of the transparent electrodes 42Y and 42Z and the bus electrodes 43Y and 43Z whose width is smaller than the width of the transparent electrodes 42Y and 42Z.
Also, the transparent electrodes 42Y and 42Z include the connection parts 42b formed along the first barrier ribs 54a that partition off the hexagonal discharge cells in delta and the extension parts 42a1 and 42a2 that are extended from the connection parts 42b to the insides of the discharge cells with predetermined width and that face each other to make pairs as described in the first embodiment.
Also, the data electrodes arranged on the rear surface substrate may be divided into wide parts X1 and narrow parts X2. At this time, the maximum width d′ of the wide parts X1 of the data electrodes is about 75% to 150% of the maximum width of the extension parts 42a1 and 42a2 of the transparent electrodes and the maximum width d of the narrow parts X2 of the data electrodes is about 5% to 75% of the maximum width of the extension parts 42a1 and 42a2 of the transparent electrodes.
As described above, the wide parts X1 are provided in the data electrodes in order to improve the efficiency of facing discharge (address discharge) generated between the scan electrodes and the data electrodes. Recently, a gap between the scan electrodes and the sustain electrodes is large in order to improve discharge efficiency. When the data electrodes have the wide parts X1, although a long gap is formed between the scan electrodes and the sustain electrodes, a discharge voltage for facing discharge does not significantly increase so that it is possible to improve driving efficiency.
The wide part X1 of the data electrode having the above-described structure may be formed of an electrode whose width is larger than the width of the narrow part X2 without a hole or an electrode including a hole between a plurality of narrow parts X3.
Also, the width d′ of the wide parts X1 may vary in at least one discharge cell in accordance with the discharge characteristics of the R, G, and B discharge cells. For example, the width d′ of the wide parts X1 may be in the order of B>G>R or B>R>G.
As illustrated in
A hole is formed between the narrow parts X3 so that the width h of the hole is 5% to 80% of the maximum width of the extension parts 42a1 and 42a2 of the transparent electrodes and 50% to 110% of the width of the second barrier rib 54b.
When the width h of the hole is smaller than 50% of the width of the second barrier rib 54b, the size of the hole is so small that it is not possible to save the material cost of the data electrode. When the width h of the hole is larger than 110%, since the size of the hole is so large that the widths d1 and d2 of the narrow parts of the data electrode are reduced, the efficiency of facing discharge between the pair of sustain electrodes and the data electrode deteriorates.
As described above, according to the third embodiment, the width d′ of the data electrode is large in the discharge space and then, the hole is formed in the data electrode in the discharge space so that a distance between the effective side surfaces of the scan electrode and the data electrode that participate in address discharge is reduced. Therefore, it is possible to reduce jitter generated during address discharge and to thus improve the discharge efficiency of the PDP.
The first extension part 42c1 that intersects the data electrode X and that is extended from the scan electrode Y and the second extension part 42c2 that intersects the data electrode X and that is extended from the sustain electrode Z are provided in the discharge cell. Here, the first and second extension parts 42c1 and 42c2 face each other.
The first and second depressed parts 42d1 and 42d2 are formed on the facing surfaces of the first and second extension parts 42c1 and 42c2 so that the distance between the centers C of the first and second extension parts 42c1 and 42c2 is different from the distance between the edges E of the first and second extension parts 42c1 and 42c2. The first and second depressed parts 42d1 and 42d2 may be polygonal and circular as illustrated in
The length of the long gap between the transparent electrodes formed by the first and second depressed parts 42d1 and 42d2 is within 60 to 180 μm based on a resolution VGA level.
Also, the data electrodes arranged on the rear surface substrate may be divided into wide parts X1 and narrow parts X2. At this time, the maximum width d′ of the wide parts X1 of the data electrodes is about 75% to 150% of the maximum width of the extension parts 42c1 and 42c2 of the transparent electrodes and the maximum width d of the narrow parts X2 of the data electrodes is about 5% to 75% of the maximum width of the extension parts 42c1 and 42c2 of the transparent electrodes.
The wide part X1 of the data electrode may be formed of an electrode whose width is larger than the width of the narrow part X2 without a hole or an electrode including a hole between a plurality of narrow parts X3.
Also, the width d′ of the wide parts X1 may vary in at least one discharge cell in accordance with the discharge characteristics of the R, G, and B discharge cells. For example, the width d′ of the wide parts X1 may be in the order of B>G>R or B>R>G.
As illustrated in
The width h of the hole formed between the narrow parts X3 is 5% to 80% of the maximum width of the extension parts 42c1 and 42c2 of the transparent electrodes and 50% to 110% of the width of the second barrier rib 54b.
Therefore, according to the fourth embodiment, since the depressed parts 42d1 and 42d2 are formed in the first and second extension parts 42c1 and 42c2, a long gap is formed so that the efficiency of sustain discharge is improved. Also, since the width of the data electrode in the discharge space increases due to the plurality of narrow parts X3 and the hole between the narrow parts X3 in the wide part X1 of the data electrode, the distance between the effective side surfaces of the data electrode and the pair of sustain electrodes is reduced so that the efficiency of address discharge is improved.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be comprised within the scope of the following claims.
Number | Date | Country | Kind |
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10-2005-0049975 | Jun 2005 | KR | national |
10-2005-0080264 | Aug 2005 | KR | national |
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