The present invention relates to a plasma display panel.
The present invention relates to a plasma display panel.
Generally, a phosphor layer and a plurality of electrodes are formed inside a discharge cell partitioned by barrier ribs of the plasma display panel.
When driving signals are applied to the electrodes of the plasma display panel, a discharge occurs inside the discharge cell due to the supplied driving signals. In other words, when the discharge occurs inside the discharge cell due to the supplied driving signals, a discharge gas filled in the discharge cell generates vacuum ultraviolet rays, which thereby cause a phosphor inside the discharge cell to emit light, thus producing visible light. An image is displayed on the screen of the plasma display panel due to the visible light.
An exemplary embodiment of the present invention provides a plasma display panel capable of improving a contrast characteristic of an image by reducing a panel reflectance.
A plasma display panel according to an exemplary embodiment of the present invention comprises a front substrate on which a first electrode and a second electrode are positioned parallel to each other, a first black layer at a position corresponding to the first electrode, a second black layer at a position corresponding to the second electrode, a rear substrate positioned opposite the front substrate, and a barrier rib positioned between the front substrate and the rear substrate to partition a discharge cell, wherein an interval between the first black layer and the second black layer ranges from 0.7 to 2.5 times a shortest interval between at least one of the first and second black layers and the barrier rib.
The interval between the first black layer and the second black layer may range from 0.8 to 1.8 times the shortest interval between at least one of the first and second black layers and the barrier rib.
The plasma display panel may further comprise a third black layer on the front substrate at a position corresponding to the barrier rib.
The plasma display panel may further comprise a fourth black layer on an upper portion of the barrier rib.
A shortest interval between at least one of the first and second black layers and the fourth black layer may be substantially equal to the shortest interval between at least one of the first and second black layers and the barrier rib.
The first electrode and the second electrode may each include a transparent electrode and a bus electrode. The first and second black layers may be positioned between the transparent electrodes of the first and second electrodes and the bus electrodes of the first and second electrodes, respectively.
The first electrode and the second electrode may be spaced apart from the barrier rib parallel to at least one of the first electrode and the second electrode.
The shortest interval between the barrier rib and the first black layer may be substantially equal to the shortest interval between the barrier rib and the second black layer.
The shortest interval between the barrier rib and the first black layer, the shortest interval between the barrier rib and the second black layer, and the interval between the first black layer and the second black layer may be substantially equal to one another.
The barrier rib may include a first barrier rib parallel to the first and second black layers, and a second barrier rib intersecting the first barrier rib. A fifth black layer may be positioned on the front substrate at a position corresponding to the second barrier rib to intersect the first and second black layers.
The first electrode and the second electrode may each include a transparent electrode and a bus electrode. Each of the transparent electrodes of the first and second electrodes may include a first portion which does not overlap the first black layer or the second black layer, a second portion which does not overlap the first black layer or the second black layer, a distance from the second portion to the middle of the discharge cell being shorter than a distance from the first portion to the middle of the discharge cell, and a third portion which is positioned between the first portion and the second portion and overlaps the first black layer or the second black layer. A length of a cross section of the second portion may be shorter than a length of a cross section of the first portion.
A plasma display panel according to an exemplary embodiment of the present invention comprises a front substrate on which a first electrode and a second electrode are positioned parallel to each other, a first black layer at a position corresponding to the first electrode, a second black layer at a position corresponding to the second electrode, a rear substrate positioned opposite the front substrate, a barrier rib positioned between the front substrate and the rear substrate to partition a discharge cell, and a third black layer on the front substrate at a position corresponding to the barrier rib, wherein an interval between the first black layer and the second black layer ranges from 0.7 to 2.5 times a shortest interval between at least one of the first and second black layers and the third black layer.
The interval between the first black layer and the second black layer may range from 0.8 to 1.8 times the shortest interval between at least one of the first and second black layers and the third black layer.
The shortest interval between the third black layer and the first black layer, the shortest interval between the third black layer and the second black layer, and the shortest interval between the first black layer and the second black layer may be substantially equal to one another.
The first electrode and the second electrode may each include a transparent electrode and a bus electrode. Each of the transparent electrodes of the first and second electrodes may include a first portion which does not overlap the first black layer or the second black layer, a second portion which does not overlap the first black layer or the second black layer, a distance from the second portion to the middle of the discharge cell being shorter than a distance from the first portion to the middle of the discharge cell, and a third portion which is positioned between the first portion and the second portion and overlaps the first black layer or the second black layer. A length of a cross section of the second portion may be shorter than a length of a cross section of the first portion.
A plasma display panel according to an exemplary embodiment of the present invention comprises a front substrate on which a first electrode and a second electrode are positioned parallel to each other, the first electrode and the second electrode each including a transparent electrode and a bus electrode, a rear substrate positioned opposite the front substrate, a barrier rib positioned between the front substrate and the rear substrate to partition a discharge cell, and a third black layer on the front substrate at a position corresponding to the barrier rib, wherein an interval between the bus electrodes of the first and second electrodes ranges from 0.7 to 2.5 times a shortest interval between at least one of the bus electrodes of the first and second electrodes and the third black layer.
The interval between the bus electrodes of the first and second electrodes may range from 0.8 to 1.8 times the shortest interval between at least one of the bus electrodes of the first and second electrodes and the third black layer.
Each of the transparent electrodes of the first and second electrodes may include a first portion which does not overlap the bus electrode, a second portion which does not overlap the bus electrode, a distance from the second portion to the middle of the discharge cell being shorter than a distance from the first portion to the middle of the discharge cell, and a third portion which is positioned between the first portion and the second portion and overlaps the bus electrode. A length of a cross section of the second portion may be shorter than a length of a cross section of the first portion.
A degree of darkness of the bus electrode may be higher than a degree of darkness of the transparent electrode.
The bus electrode may include a black material having electrical conductivity.
A plasma display panel according to the present invention reduces a panel reflectance using an eclipse effect by relatively widening an interval between a first black layer or a second black layer positioned between a first electrode or a second electrode and a front substrate and a barrier rib, and thus improves a contrast characteristic of an image displayed on the plasma display panel.
As shown in
The first electrode 102 and the second electrode 103 may each include transparent electrodes 102a and 103a and bus electrodes 102b and 103b.
The transparent electrodes 102a and 103a may include a substantially transparent material having electrical conductivity such as indium-tin-oxide (ITO).
The bus electrodes 102b and 103b may include a metal material having excellent electrical conductivity such as silver (Ag).
A first black layer 106 may be positioned on the front substrate 101 at a position corresponding to the first electrode 102, and a second black layer 107 may be positioned on the front substrate 101 at a position corresponding to the second electrode 103.
For instance, as shown in
It may be preferable that a degree of darkness of the first and second black layers 106 and 107 is higher than a degree of darkness of the first electrode 102 or the second electrode 103. In other words, the first and second black layers 106 and 107 have a color darker than the first electrode 102 or the second electrode 103.
The first and second black layers 106 and 107 may be formed of the substantially same material. For instance, the first and second black layers 106 and 107 may include ruthenium (Ru)-based material or cobalt (Co)-based material.
The first and second black layers 106 and 107 prevent light coming from the outside from being reflected by the first and second electrodes 102 and 103, thereby reducing a reflectance.
An upper dielectric layer 104 may be positioned on the first electrode 102 and the second electrode 103 to limit a discharge current of the first electrode 102 and the second electrode 103 and to provide electrical insulation between the first electrode 102 and the second electrode 103.
A protective layer 105 may be formed on the upper dielectric layer 104 to facilitate discharge conditions. The protective layer 105 may include a material having a high secondary electron emission coefficient, for example, magnesium oxide (MgO).
The third electrode 113 is formed on the rear substrate 111, and a lower dielectric layer 115 may be formed on the third electrode 113 to provide electrical insulation of the third electrodes 113.
Barrier ribs 112 of a stripe type, a well type, a delta type, a honeycomb type, and the like, may be positioned on the lower dielectric layer 115 to partition discharge spaces (i.e., discharge cells). Hence, a first discharge cell emitting red (R) light, a second discharge cell emitting blue (B) light, and a third discharge cell emitting green (G) light, and the like, may be formed between the front substrate 101 and the rear substrate 111.
In addition to the first, second, and third discharge cells, a fourth discharge cell emitting white (W) light or yellow (Y) light may be further formed.
While widths of the first, second, and third discharge cells may be substantially equal to one another, a width of at least one of the first, second, and third discharge cells may be different from widths of the other discharge cells.
For instance, a width of the first discharge cell emitting red (R) light may be the smallest, and widths of the second discharge cell emitting blue (B) light and the third discharge cell emitting green (G) light may be larger than the width of the first discharge cell. Hence, a color temperature of a displayed image can be improved. The width of the second discharge cell may be substantially equal to or different from the width of the third discharge cell.
The plasma display panel may have various forms of barrier rib structures as well as a structure of the barrier rib 112 shown in
Further, the barrier rib 112 may have a channel type barrier rib structure in which a channel usable as an exhaust path is formed on at least one of the first barrier rib 112b or the second barrier rib 112a, a hollow type barrier rib structure in which a hollow is formed on at least one of the first barrier rib 112b or the second barrier rib 112a, and the like.
While
While
A phosphor layer 114 may be positioned inside the discharge cells to emit visible light for an image display during an address discharge. For instance, first, second, and third phosphor layers that produce red, blue, and green light, respectively, may be positioned inside the discharge cells.
In addition to the first, second, and third phosphor layers, a fourth phosphor layer producing white and/or yellow light may be further positioned.
A thickness of at least one of the first, second, and third phosphor layers may be different from thicknesses of the other phosphor layers. For instance, a thickness of the second phosphor layer or the third phosphor layer may be larger than a thickness of the first phosphor layer. The thickness of the second phosphor layer may be substantially equal or different from the thickness of the third phosphor layer.
In
While the third electrode 113 may have a substantially constant width or thickness, a width or thickness of the third electrode 113 inside the discharge cell may be different from a width or thickness of the third electrode 113 outside the discharge cell. For instance, a width or thickness of the third electrode 113 inside the discharge cell may be larger than a width or thickness of the third electrode 113 outside the discharge cell.
As shown in
At least one of the shortest interval G1 between the first black layer 106 and the barrier rib 112 and the shortest interval G3 between the second black layer 107 and the barrier rib 112 is set to be relatively wide. Preferably, the interval G2 between the first black layer 106 and the second black layer 107 may range from 0.7 to 2.5 times at least one of the shortest interval G1 between the first black layer 106 and the barrier rib 112 and the shortest interval G3 between the second black layer 107 and the barrier rib 112, Accordingly, a relationship of 0.7G1≦G2≦2.5G1 or 0.7G3≦G2≦2.5G3 is satisfied.
The first electrode 102 and the second electrode 103 may be spaced apart from the first barrier rib 112 parallel to at least one of the first electrode 102 and the second electrode 103 at a predetermined distance. Accordingly, it can be easier to satisfy the relationship of 0.7G1≦G2≦2.5G1 or 0.7G3≦G2≦2.5G3.
The shortest interval G1 between the first black layer 106 and the barrier rib 112 may be substantially equal to the shortest interval G3 between the second black layer 107 and the barrier rib 112.
In the present invention, the shortest interval G1 between the first black layer 106 and the barrier rib 112 is set at a shortest interval between upper portions of the first black layer 106 and the barrier rib 112, and the shortest interval G3 between the second black layer 107 and the barrier rib 112 is set at a shortest interval between upper portions of the second black layer 107 and the barrier rib 112. However, the shortest interval G1 between the first black layer 106 and the barrier rib 112 may be set at a shortest interval between lower portions of the first black layer 106 and the barrier rib 112, and the shortest interval G3 between the second black layer 107 and the barrier rib 112 may be set at a shortest interval between lower portions of the second black layer 107 and the barrier rib 112.
In case that an interval S2 between the first electrode 102 and the second electrode 103 is excessively wide, a firing voltage between the first electrode and the second electrode 103 may excessively rise. Therefore, the driving efficiency may be reduced.
On the other hand, in case that the interval S2 between the first electrode 102 and the second electrode 103 is excessively narrow, a positive column region during a discharge cannot be sufficiently used. Therefore, a luminance may be reduced.
Considering this, it may be advantageous that the interval S2 between the first electrode 102 and the second electrode 103 is equal to or more than approximately 80 μm, and preferably equal to or more than approximately 90 μm.
A width of each of the first electrode 102 and the second electrode 103 will be described below.
In case that widths W1 and W2 of the transparent electrodes 102a and 103a of the first and second electrodes 102 and 103 are excessively large, the interval S2 between the first electrode 102 and the second electrode 103 may be excessively narrow. Hence, because a positive column region during a discharge cannot be sufficiently used, the luminance may be reduced.
On the other hand, in case that the widths W1 and W2 of the transparent electrodes 102a and 103a of the first and second electrodes 102 and 103 are excessively small, electrical resistances of the first and second electrodes 102 and 103 are large. Hence, the driving efficiency may be reduced.
Considering this, it may be preferable that a sum (W1+W2) of the widths W1 and W2 of the transparent electrodes 102a and 103a of the first and second electrodes 102 and 103 ranges from 60% to 90% of a pitch S1 of the discharge cell (i.e., the distance S1 between the adjacent two barrier ribs 112 parallel to the first and second electrodes 102 and 103).
The transparent electrodes 102a and 103a of the first and second electrodes 102 and 103 will be described below in detail with reference to
As shown in
A length of a cross section of the second portion P2 may be shorter than a length of a cross section of the first portion P1. In other words, the bus electrodes 102b and 103b of the first and second electrodes 102 and 103 may positioned on the transparent electrodes 102a and 103a to be close to the center of the discharge cell.
It is assumed that in the panel structure of
A portion of light rays obliquely incident on the panel is blocked by the first black layer 300, the second black layer 310, and the barrier 312, and thus a shadow generated by the first black layer 300, the second black layer 310, and the barrier 312 covers a portion of the discharge cell. However, because the first black layer 300 is adjacent to the barrier 312 or the second black layer 310 is adjacent to the barrier 312, as shown in
Accordingly, the viewer watches the light reflected in the area W, and thus a contrast characteristic of an image displayed on the panel may be reduced.
On the other hand, when the interval between the first black layer 106 and the barrier rib 112 or the interval between the second black layer 107 and the barrier rib 112 are relatively wide as shown in
Because the interval between the first black layer 106 and the barrier rib 112 is sufficiently wide and also the interval between the second black layer 107 and the barrier rib 112 is sufficiently wide, a shadow generated by the first black layer 106, the second black layer 107, and the barrier rib 112 may cover the most area of the discharge cell.
Although the viewer in the front of panel watches an image displayed on the panel, an intensity of the reflected light which the viewer watches may be weaker than an intensity of the reflected light in the case described in
As show in
When the interval G2 is 3.0 times the shortest interval G1 or G3, as shown in
On the other hand, when the interval G2 is 0.7 time the shortest interval G1 or G3, the panel reflectance may be sharply reduced to approximately 21%. When the interval G2 ranges from 0.7 to 2.5 times the shortest interval G1 or G3, the panel reflectance may have a stable value ranging from 18% to 22% because of the eclipse effect described in
As show in
On the other hand, when the interval G2 ranges from 0.7 to 2.5 times the shortest interval G1 or G3, the middle portion of the discharge cell is open. Hence, the luminance may range from 170 cd/m2 to 202 cd/m2.
When the interval G2 exceeds 2.5 times the shortest interval G1 or G3, the luminance may saturate in a range between 202 cd/m2 and 203 cd/m2.
Considering the panel reflectance of
It may be more advantageous that the interval G2 between the first black layer 106 and the second black layer 107 ranges from 0.7 to 2.0 times or from 0.8 to 1.8 times at least one of the shortest interval G1 between the first black layer 106 and the barrier rib 112 and the shortest interval G3 between the second black layer 107 and the barrier rib 112, so as to reduce the panel reflectance and to improve the luminance.
The interval G2 between the first black layer 106 and the second black layer 107 may be substantially equal to at least one of the shortest interval G1 between the first black layer 106 and the barrier rib 112 and the shortest interval G3 between the second black layer 107 and the barrier rib 112.
As shown in
In this case, a shortest interval between the third black layer 200 and the first black layer 106, a shortest interval between the first black layer 106 and the second black layer 107, and a shortest interval between the third black layer 210 and the second black layer 107 may be indicated as G4, G5, and G6, respectively.
A relationship of 0.7G4≦G5≦2.5G4 or 0.7G6≦G5≦2.5G6 may be satisfied so as to achieve an eclipse effect.
Comparing
Widths of the third black layers 200 and 210 may be substantially equal to a width of an upper portion or a lower portion of the barrier rib 112. The widths of the third black layers 200 and 210 may be larger than the width of the upper portion or the lower portion of the barrier rib 112 by approximately 10 μm to 40 μm in consideration of an error of manufacturing process.
As shown in
In this case, a shortest interval between the fourth black layer 500 and the first black layer 106, a shortest interval between the first black layer 106 and the second black layer 107, and a shortest interval between the fourth black layer 510 and the second black layer 107 may be indicated as G7, G8, and G9, respectively.
A relationship of 0.7G7≦G8≦2.5G7 or 0.7G9≦G8≦2.5G9 may be satisfied so as to achieve the above-described eclipse effect.
Comparing
As shown in
As shown in (b) of
As above, the bus electrodes 602b and 603b combined with the first and second black layers 106 and 107 may be formed of a material obtained by mixing an electrode material with a black material having a degree of darkness higher than a degree of darkness of the electrode material.
Because the formation of the bus electrodes 602b and 603b combined with the black layer reduces the number of manufacturing processes and time required in the manufacturing process, the manufacturing cost can be reduced.
In this case, as shown in
A relationship of 0.7G11≦G12≦2.5G11 or 0.7G13≦G12≦2.5G13 may be satisfied so as to achieve the above-described eclipse effect.
Comparing
As shown in
Although it is not shown in
A portion of the fifth black layer 1300, as shown in
As shown in
The formation of the fifth black layer 1300 can further reduce the panel reflectance, and thus the contrast characteristic of the image can be improved.
As shown in
For instance, the rising signal RS may be supplied to the scan electrode Y during a setup period SU of the reset period RP, and the falling signal FS may be supplied to the scan electrode Y during a set-down period SD following the setup period SU.
When the rising signal RS is supplied to the scan electrode Y, a weak dark discharge (i.e., a setup discharge) occurs inside the discharge cell due to the rising signal RS. Hence, the remaining wall charges may be uniformly distributed inside the discharge cell.
When the falling signal FS is supplied to the scan electrode Y after the supply of the rising signal RS, a weak erase discharge (i.e., a set-down discharge) occurs inside the discharge cell. Hence, the remaining wall charges may be uniformly distributed inside the discharge cells to the extent that an address discharge occurs stably.
During an address period AP following the reset period RP, a scan bias signal Vsc having a voltage higher than a lowest voltage of the falling signal FS may be supplied to the scan electrode Y.
A scan signal Scan falling from the scan bias signal Vsc may be supplied to the scan electrode Y during the address period AP.
A width of a scan signal supplied to the scan electrode during an address period of at least one subfield may be different from widths of scan signals supplied during address periods of the other subfields. For instance, a width of a scan signal in a subfield may be larger than a width of a scan signal in a next subfield in time order. A width of a scan signal may be gradually reduced in the order of 2.6 μs, 2.3 μs, 2.1 μs, 1.9 μs, etc., or may be reduced in the order of 2.6 μs, 2.3 μs, 2.3 μs, 2.1 μs, ? 1.9 μs, 1.9 μs, etc., in the successively arranged subfields.
When the scan signal Scan is supplied to the scan electrode Y, a data signal Data corresponding to the scan signal Scan may be supplied to the address electrode X.
As the voltage difference between the scan signal Scan and the data signal Data is added to a wall voltage by the wall charges produced during the reset period RP, an address discharge can occur inside the discharge cells to which the data signal Data is supplied.
During a sustain period SP following the address period AP, a sustain signal SUS may be supplied to at least one of the scan electrode Y or the sustain electrode Z. For instance, the sustain signal SUS may be alternately supplied to the scan electrode Y and the sustain electrode Z.
As the wall voltage inside the discharge cells selected by performing the address discharge is added to a sustain voltage Vs of the sustain signal SUS, every time the sustain signal SUS is supplied, a sustain discharge (i.e., a display discharge) can occur between the scan electrode Y and the sustain electrode Z. Hence, an image can be displayed on the screen of the plasma display panel.
While the present invention have been described with reference to the attached drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.
Rather, the exemplary embodiments of the present invention are provided so that this disclosure will be thorough and complete and fully conveys the concept of the invention to those of ordinary skill in the art. 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 those of ordinary skilled in the art are intended to be included within the scope of the following claims.
Number | Date | Country | Kind |
---|---|---|---|
10-2006-0129024 | Dec 2006 | KR | national |
10-2006-0138005 | Dec 2006 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/KR2007/006602 | 12/17/2007 | WO | 00 | 9/30/2008 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2008/072940 | 6/19/2008 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
20020047558 | Whang et al. | Apr 2002 | A1 |
20040041522 | Takada et al. | Mar 2004 | A1 |
20050231117 | Joo et al. | Oct 2005 | A1 |
20060145613 | Kim | Jul 2006 | A1 |
20060164011 | Lee et al. | Jul 2006 | A1 |
20060170354 | Hwang | Aug 2006 | A1 |
20070278954 | Ryu et al. | Dec 2007 | A1 |
20070285011 | Bae | Dec 2007 | A1 |
Number | Date | Country |
---|---|---|
1724807 | Nov 2006 | EP |
2000-133147 | May 2000 | JP |
2002-025451 | Jan 2002 | JP |
2003-151450 | May 2003 | JP |
2006-216554 | Aug 2006 | JP |
2006-318901 | Nov 2006 | JP |
10-2003-0037487 | May 2003 | KR |
10-2004-0102419 | Dec 2004 | KR |
10-2005-0114068 | Dec 2005 | KR |
10-2006-0026607 | Mar 2006 | KR |
10-2006-0068267 | Jun 2006 | KR |
10-2006-0117491 | Nov 2006 | KR |
Number | Date | Country | |
---|---|---|---|
20090109140 A1 | Apr 2009 | US |