WO2009005198A1

WO2009005198A1 - Plasma display panel

Info

Publication number: WO2009005198A1
Application number: PCT/KR2007/007055
Authority: WO
Inventors: Jihoon Lee; Gibum Lee; Seongnam Ryu; Jongmun Yang; Myongsoon Jung; Jain Goo; Jeonghyun Hahm; Hyeonjae Lee; Jinyoung Kim
Original assignee: Lg Electronics Inc.
Priority date: 2007-07-04
Filing date: 2007-12-31
Publication date: 2009-01-08

Abstract

A plasma display panel is disclosed. The plasma display panel includes a front substrate on which a scan electrode and a sustain electrode are positioned substantially parallel to each other, a rear substrate on which an address electrode is positioned to intersect the scan and sustain electrodes, and a barrier rib positioned between the front substrate and the rear substrate. The scan and sustain electrodes each includes a transparent electrode and a bus electrode. The transparent electrode includes a first portion including a plurality of holes, a second portion including a plurality of projections projecting in a direction substantially parallel to the address electrode, and a third portion that is positioned between the first portion and the second portion and overlaps the bus electrode.

Description

Description PLASMA DISPLAY PANEL

Technical Field

[I] An exemplary embodment relates to a plasma display panel. Background Art

[2] A plasma display panel includes a phosphor layer insϋe dscharge cells partitioned by barrier ribs and a plurality of electrodes.

[3] When driving sgnals are applied to the electrodes of the plasma display panel, a discharge occurs insϋe the discharge cells. In other words, when the plasma display panel is discharged by applying the driving sgnals to the discharge cells, a discharge gas filled in the discharge cells generates vacuum ultraviolet rays, which thereby cause phosphors positioned between the barrier ribs to emit light, thus producing visible light. An image is displayed on the screen of the plasma display panel due to the viable light.

Disclosure of Invention Brief Description of the Drawings

[4] FIGs. 1 and 2 show a structure of a plasma display panel according to an exemplary embodiment; [5] FIG. 3 illustrates an example of an operation of the plasma display panel according to the exemplary embodiment;

[6] FIGs. 4 and 5 show a scan electrode and a sustain electrode;

[7] FIG. 6 is a diagram for explaining a driving efficiency of the plasma display panel according to the exemplary embodiment;

[8] FIGs. 7 to 9 are a diagram for explaining a width of hole;

[9] FIG. 10 is a table showing a relationship between a sum of areas of scan and sustain electrodes and an area of a front substrate; [10] FIG. 11 is a table showing a relationship between an area of a discharge cell and a sum of areas of scan and sustain electrodes inside the discharge cell;

[I I] FIG. 12 is a diagram for explaining the arrangement of holes and projections; [12] FIGs. 13 and 14 show another form of hole;

[13] FIG. 15 shows another form of projection; and

[14] FIG. 16 is a diagram for explaining the disposition of a scan electrode and a sustain electrode.

Mode for the Invention [15] FIGs. 1 and 2 show a structure of a plasma display panel according to an exemplary embodiment.

[16] As shown in FIG. 1, a plasma display panel according to an exemplary embodiment includes a front substrate 101, on which a scan electrode 102 and a sustain electrode 103 are positioned substantially parallel to each other, and a rear substrate 111 on whbh an address electrode 113 is positioned to intersect the scan electrode 102 and the sustain electrode 103.

[17] An upper dielectric layer 104 is positioned on the scan electrode 102 and the sustain electrode 103 to provide electrical insulation between the scan electrode 102 and the sustain electrode 103.

[18] A protective layer 105 is positioned 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).

[19] A lower dielectric layer 115 is positioned on the address electrode 113 to provide electrical insulation of the address electrodes 113.

[20] Barrier ribs 112 of a stripe type, a well type, a delta type, a honeycomb type, and the like, are positioned on the lower dielectric layer 115 to partition discharge spaces (ie., discharge cells). A red (R) discharge cell, a green (G) discharge cell, and a blue (B) discharge cell, and the like, may be positioned between the front substrate 101 and the rear substrate 111. In addition to the red (R), green (G), and blue (B) dscharge cells, a white (W) discharge cell or a yellow (Y) discharge cell may be further positioned.

[21] Widths of the red (R), green (G), and blue (B) discharge cells may be substantially equal to one another. Further, a width of at least one of the red (R), green (G), or blue (B) discharge cells may be different from widths of the other discharge cells. For instance, a width of the red (R) discharge cell may be the smallest, and widths of the green (G) and blue (B) discharge cells may be larger than the width of the red (R) discharge cell. The width of the green (G) discharge cell may be substantially equal or different from the width of the blue (B) discharge cell. Hence, a color temperature of an image displayed on the plasma display panel can be improved.

[22] The plasma display panel may have various forms of barrier rib structures as well as a structure of the barrier rib 112 shown in FIG. 1. For instance, the barrier rib 112 includes a first barrier rib 112b and a second barrier rib 112a. The barrier rib 112 may have a differential type barrier rib structure in which heights of the first and second barrier ribs 112b and 112a are different from each other.

[23] In the differential type barrier rib structure, a height of the first barrier rib 112b may be smaller than a height of the second barrier rib 112a.

[24] While FIG. 1 has been illustrated and described the case where the red (R), green (G) and blue (B) discharge cells are arranged on the same line, the red (R), green (G) and blue (B) discharge cells may be arranged in a different pattern. For instance, a delta type arrangement in which the red (R), green (G), and blue (B) discharge cells are arranged in a triangle shape may be applicable. Further, the dscharge cells may have a variety of polygonal shapes such as pentagonal and hexagonal shapes as well as a rectangular shape.

[25] While FIG. 1 has illustrated and described the case where the barrier rib 112 is formed on the rear substrate 111, the barrier rib 112 may be formed on at least one of the front substrate 101 or the rear substrate 111.

[26] Each discharge cell partitioned by the barrier ribs 112 may be filled with a predetermined discharge gas.

[27] A phosphor layer 114 is positioned inside the discharge cells to emit viable light for an image display during an address discharge. For instance, red, green, and blue phosphor layers may be positioned inade the dscharge cells. In addition to the red, green, and blue phosphor layers, at least one of white or yellow phosphor layer may be further positioned.

[28] A thickness of at least one of the phosphor layers 114 formed inskie the red (R), green (G) and blue (B) discharge cells may be different from thicknesses of the other phosphor layers. For instance, a thickness of the green phosphor layer or the blue phosphor layer may be larger than a thickness of the red phosphor layer. The thickness of the green phosphor layer may be substantially equal or different from the thickness of the blue phosphor layer.

[29] FIG. 2 shows another structire of the scan electrode 102 and the sustain electrode

103.

[30] As shown in FIG. 2, each of the scan electrode 102 and the sustain electrode 103 may have a multi-layered structure. For instance, the scan electrode 102 and the sustain electrode 103 each include transparent electrodes 102a and 103a and bus electrodes 102b and 103b.

[31] The bus electrodes 102b and 103b may include a substantially opaque material, for instance, silver (Ag), gold (Au), and aluminum (Al). The transparent electrodes 102a and 803a may include a substantially transparent material, for instance, indiim- tin-oxide (ITO).

[32] Black layers 120 and 130 may be formed between the transparent electrodes 102a and 103a and the bus electrodes 102b and 103b so as to prevent the reflection of external light caused by the bus electrodes 102b and 103b.

[33] In FIG. 1, the upper dielectric layer 104 and the lower dielectric layer 115 each have a single-layered structure. However, at least one of the upper dielectric layer 104 or the lower dielectric layer 115 may have a multi-layered structure.

[34] A black matrix (not shown) capable of absorbing external light may be formed on the barrier rib 112 so as to prevent the reflection of external light caused by the barrier rib 112. The black matrix may be positioned on a predetermined location of the front substrate 101 to correspond to the barrier rib 112.

[35] While the address electrode 113 may have a substantially constant width or thickness, a width or thickness of the address electrode 113 inskie the discharge cell may be different from a width or thickness of the address electrode 113 outside the discharge cell. For instance, a width or thickness of the address electrode 113 inside the discharge cell may be larger than a width or thickness of the address electrode 113 outside the discharge cell.

[36] FIG. 3 illustrates an example of an operation of the plasma display panel according to the exemplary embodiment. The exemplary embodiment is not limited to FIG. 3, and the plasma display can be operated in various manners.

[37] As shown in FIG. 3, during a reset period for initialization, a reset agnal is supplied to the scan electrode. The reset signal includes a rising agnal and a falling agnal. The reset period is further divided into a setup period and a set-down period.

[38] The rising agnal is supplied to the scan electrode during the setup period, thereby generating a weak dark discharge (ie., a setup discharge) inskie the discharge cell. Hence, a proper amount of wall charges are accumulated inside the discharge cell.

[39] The falling agnal of a polarity opposite a polarity of the rising agnal is supplied to the scan electrode during the set-down period, thereby generating a weak erase discharge (ie., a set-down discharge) inskie the discharge cell. Hence, the remaining wall charges are uniform inade the discharge cells to the extent that an address discharge occurs stably.

[40] During an address period following the reset period, a scan bias agnal, which is substantially maintained at a sixth voltage V6 higher than a lowest voltage V5 of the falling agnal, is supplied to the scan electrode.

[41] A scan agnal falling from the scan bias agnal is supplied to the scan electrode.

[42] A width of a scan agnal supplied during an address period of at least one subfield may be different from widths of scan agnals supplied during address periods of the other subfields. A width of a scan sgnal in a subfield may be larger than a width of a scan signal in a next subfield in time order. For instance, a width of the scan sgnal may be gradually reduced in the order of 2.6μs, 2.3//S, 2.1//S, 1.9//S, etc., or may be reduced in the order of 2.6μs, 2.3μs, 2.3μs, 2.1//S, 1.9μs, 1.9μs, etc, in the successively arranged subfields.

[43] As above, when the scan agnal is supplied to the scan electrode, a data sgnal corresponding to the scan agnal is supplied to the address electrode.

[44] As the voltage difference between the scan agnal and the data agnal is added to the wall voltage produced duing the reset period, the address discharge occurs insde the discharge cell to which the data agnal is supplied.

[45] A sustain bias agnal is supplied to the sustain electrode duing the address period so as to prevent the generation of unstable address discharge by interference of the sustain electrode.

[46] The sustain bias agnal is substantially maintained at a sustain bias voltage Vz. The sustain bias voltage Vz is lower than a voltage Vs of a sustain agnal and is higher than a ground level voltage GND.

[47] During a sustain period following the address period, the sustain agnal may be supplied to at least one of the scan electrode or the sustain electrode. For instance, the sustain agnal is alternately supplied to the scan electrode and the sustain electrode.

[48] As the wall voltage inade the discharge cell selected by performing the address discharge is added to the sustain voltage Vs of the sustain agnal, every time the sustain agnal is supplied, a sustain discharge, ie., a display dscharge occurs between the scan electrode and the sustain electrode.

[49] A plurality of sustain sgnals are supplied during a sustain period of at least one subfield, and a width of at least one of the plurality of sustain agnals may be different from widths of the other sustain agnals. For instance, a width of a first supplied sustain agnal among the plurality of sustain agnals may be larger than widths of the other sustain agnals. Hence, a sustain discharge can more stably occur.

[50] FIGs. 4 and 5 shows the scan electrode 102 and the sustain electrode 103.

[51] As shown in FIG. 4, the transparent electrodes 102a and 103a each include holes 300 and projections 310. The transparent electrodes 102a and 103a overlap the bus electrodes 102b and 103b.

[52] In the scan electrode 102 as an example, as shown in FIG. 5, the transparent electrode 102a may include a first portion Wl including the plurality of holes 300, a second portion W2 including the plurality of projections 310 that project in a drection substantially parallel to the address electrode 113, and a third portion W3 that is positioned between the first portion Wl and the second portion W2 and overlaps the bus electrode 102b. The black layer 120 may be positioned between the third portion W3 and the bus electrode 102b.

[53] It may be advantageous that the plurality of holes 300 are arranged in a direction substantially parallel to the bus electrode 102b. For instance, as shown in FIGs. 4 and 5, the plurality of holes 300 may be arranged in a row arranged in a direction substantially parallel to the bus electrode 102b.

[54] The plurality of projections 310 may be arranged in a direction substantially parallel to the bus electrode 102b.

[55] Although FIG. 5 has illustrated and described the scan electrode 102 as an example, the sustain electrode 103 may have the same structure as the scan electrode 102. For instance, as shown in FIG. 4, the transparent electrode 103a of the sustain electrode 103 may include a first portion WlO including the plurality of holes 300, a second portion W20 including the plurality of projections 310 that project in a direction substantially parallel to the address electrode 113, and a third portion W30 that is positioned between the first portion WlO and the second portion W20 and overlaps the bus electrode 103b. A black layer (not shown) may be positioned between the third portion W30 and the bus electrode 103b.

[56] The first portion Wl of the scan electrode 102 may face the first portion WlO of the sustain electrode 103 at a predetermined distance therebetween in the center of the discharge cell partitioned by the barrier rib 112.

[57] The projections 310 of the scan and sustain electrodes 102 and 103 may project in a direction substantially parallel to the address electrode 113 and in a direction opposite a drection toward the center of the discharge cell.

[58] A current does not flow in the plurality of holes 300 of the first portions Wl and

WlO. Therefore, a relatively large amount of current flows in a facing area of the scan and sustain electrodes 102 and 103, and wall charges may be concentratedly ds- tributed in the facing area of the scan and sustain electrodes 102 and 103. Hence, a firing voltage between the scan electrode 102 and the sustain electrode 103 is lowered, and thus the driving effϋency can be improved. Further, because a discharge can uniformly occur between the scan electrode 102 and the sustain electrode 103, the discharge can stably occur.

[59] Further, because a discharge generated in the facing area of the scan and sustain electrodes 102 and 103 can be diffused in a downward drection of the discharge cell along the projections 310, ultraviolet rays can uniformly irradated on the phosphor layer. Hence, the generation amount of visible light can increase, and a luminance of a displayed image can be improved.

[60] The entire area of each of the scan and sustain electrodes 102 and 103 can be reduced due to the holes 300, and thus the amount of discharge current can be reduced. Hence, the driving efficiency can be improved.

[61] When an interval gl between the scan electrode 102 and the sustain electrode 103 is excessively wide, a firing voltage between the scan and sustain electrodes 102 and 103 can excessively rise. In this case, the driving efficiency and the contrast characteristic may be reduced.

[62] When the interval gl is excessively narrow, a discharge may occur between the scan electrode 102 and the sustain electrode 103 even if there is a small change in voltage. Therefore, it is difficult to control a discharge and a voltage margin may be excessively small.

[63] Accordingly, the interval gl may lie substantially in a range between 60 μm and 90 μm or 70 μm and 80 μm.

[64] The scan and sustain electrodes 102 and 103 may be spaced apart from the first barrier 112b at a predetermined distance so that the interval gl lies substantially in a range between 60 μm and 90 μm or 70 μm and 80 μm.

[65] For instance, the scan electrode 102 may be spaced apart from the first barrier 112b at a dstance of g2, and the sustain electrode 103 may be spaced apart from the first barrier 112b at a distance of g3. The distances g2 and g3 may be substantially equal to or different from each other.

[66] In case that the scan and sustain electrodes 102 and 103 are spaced apart from the first barrier 112b at the predetermined dstance, the interval gl can lie substantially in a range between 60 μm and 90 βm or 70 μm and 80 μm, even if a width of each of the scan and sustain electrodes 102 and 103 in the direction substantially parallel to the address electrode 113 does not increase excessively.

[67] If the scan and sustain electrodes 102 and 103 overlap the first barrier 112b in a state where the interval gl lies substantially in a range between 60 μm and 90 μm or 70 μm and 80 μm, the width and the area of the scan and sustain electrodes 102 and 103 may excessively increase. Hence, the amount of discharge current may increase and the driving effϋency can be reduced.

[68] FIG. 6 is a diagram for explaining a driving efficiency of the plasma display panel accordng to the exemplary embodment. [69] In FIG. 6, a 1 -typed barrier rib is formed using PbO-B ₂θ₃-Si0₂ based glass material and includes lead (Pb) more than 1,000 ppm (parts per million). A 2-typed barrier rib includes lead (Pb) equal to or less than 1,000 ppm. Further, (a)-typed panel does not include holes and projections, and (b)-typed panel includes holes and projections. For instance, in the (a)-typed panel, transparent electrodes of scan and sustain electrodes have a stripe form.

[70] When a discharge current is measured in a state where a voltage of 200V is applied to the scan electrode and a voltage of OV is applied to the sustain electrode in the (a)- and (b)-typed panels each having the 1 -typed barrier rib, as indicated in Table of FIG. 6, a discharge cvrrent of about 1.7 A flows in the (a)-typed panel and a discharge cirrent of about 1.52A flows in the (B)-typed panel. In other words, the discharge cirrent of the (b)-typed panel including the holes and projections is smaller than the discharge current of the (a)-typed panel not including the holes and projections.

[71] In case of displaying a full white image in which all the discharge cells of the panel are in an On-state, consumed power of the (a)-typed panel is about 373W, and consumed power of the (b)-typed panel is about 358W.

[72] In case of displaying 25% -window pattern image in whbh the discharge cells of 25% in the panel are in an On-state, consumed power of the (a)-typed panel is about 359W, and consumed power of the (b)-typed panel is about 347W.

[73] As above, the discharge current and the consumed power of the (b)-typed panel including the holes and projections are smaller than the discharge current and the consumed power of the (a)-typed panel not including the holes and projections, and thus the driving effϋency of the (b)-typed panel can be firmer improved.

[74] Firmer, in the (a)- and (b)-typed panels each having the 2-typed barrier rib, as indicated in Table of FIG. 6, a discharge current of about 1.62A flows in the (a)-typed panel and a discharge current of about 1.41A flows in the (b)-typed panel. In other words, the discharge cirrent of the (b)-typed panel including the holes and projections is smaller than the discharge cirrent of the (a)-typed panel not including the holes and projections. Firmer, the discharge cirrent in the 2-typed barrier rib including Pb equal to or less than 1,000 ppm is smaller than the discharge cirrent in the 1 -typed barrier rib including Pb more than 1 ,000 ppm.

[75] In case of displaying a full white image in which all the discharge cells of the panel are in an On-state, consumed power of the (a)-typed panel is about 355W, and consumed power of the (b)-typed panel is about 335W.

[76] In case of displaying 25%-window pattern image in which the discharge cells of 25% in the panel are in an On-state, consumed power of the (a)-typed panel is about 344W, and consumed power of the (b)-typed panel is about 328W.

[77] As above, the discharge current and the consumed power in the 2-typed barrier rib including Pb equal to or less than 1,000 ppm are smaller than the discharge current and the consumed power in the 1 -typed barrier rib including Pb more than 1,000 ppm, and thus the driving effϋency in the 2-typed barrier rib can be further improved.

[78] Capacitance of the barrier rib including Pb equal to or less than 1,000 ppm may be lowered, and thus the discharge current may decrease. Hence, the driving efficiency can be further improved.

[79] The electrode (for instance, the scan, sustain and address electrodes), the upper dielectric layer, the lower dielectric layer, the front substrate and the rear substrate in addition to the barrier rib may include Pb equal to or less than 1,000 ppm. Hence, the driving efficiency can be further improved.

[80] The total Pb content of the panel may be equal to or less than 1,000 ppm.

[81] FIGs. 7 to 9 are a diagram for explaining a width of hole.

[82] As shown in FIG. 7, a width of the hole 300 in a direction substantially parallel to the address electrode (not shown) is indbated as Ll, and a width of the scan electrode 102 or the sustain electrode 103 in a direction substantially parallel to the address electrode (not shown) is indbated as L2. L2 may be a width of the transparent electrode.

[83] FIGs. 8 and 9 are graphs showing a discharge current flowing in the scan electrode

102 or the sustain electrode 103 and a firing voltage between the scan electrode 102 and the sustain electrode 103 while a raio L1/L2 changes from 0.05 to 0.29 by adjusting the width Ll of the hole 300 in a state where the width L2 of the scan electrode 102 or the sustain electrode 103 is set to about 290 βm. In this case, a voltage of 200V is applied to the scan electrode 102 and a voltage of OV is applied to the sustain electrode 103.

[84] As shown in FIG. 8, when the ratio L1/L2 is 0.05, the discharge current is about 1.7A because of the excessively large total area of the scan electrode 102 or the sustain electrode 103. When the ratio L1/L2 is 0.06, the dscharge current has a relatively large value of about 1.68 A.

[85] On the contrary, when the ratio L1/L2 is 0.067, the discharge current is reduced to about 1.64A. When the ratio L1/L2 is 0.08 and 0.1, the discharge current is about 1.61 A and about 1.56 A, respectively.

[86] When the ratio L1/L2 is 0.12, the dscharge current has a relatively small value of about 1.53 A because of the sufficiently small total area of the scan electrode 102 or the sustain electrode 103. [87] Afterwards, when the ratio L1/L2 is 0.14 and 0.21, the discharge αrrent is about

1.51A and about 1.49A, respectively. When the ratio L1/L2 is 0.29, the discharge current is gradually reduced to about 1.47 A. [88] Considering the data of FIG. 8, when the ratio L1/L2 is equal to or less than 0.267, the discharge current is gradually reduced as the ratio L1/L2 gradually increases.

When the ratio L1/L2 is equal to or more than 0.29, a reduction effect of the discharge current is small and has a constant value of about 1.47 A. [89] As shown in FIG. 9, when the ratio L1/L2 is 0.05 or 0.06, a firing voltage between the scan electrode 102 and the sustain electrode 103 has a suffϋently small value of about 152V.

[90] When the ratio L1/L2 is 0.067, the firing voltage rises to about 153V.

[91] When the ratio L1/L2 is 0.08, the firing voltage is about 155V. When the ratio L1/L2 is 0.1, the firing voltage is about 157V. [92] When the ratio L1/L2 changes from 0.12 to 0.21, the firing voltage rises from about

158V to about 162V. Further, when the ratio L1/L2 changes from 0.225 to 0.267, the firing voltage rises from about 162V to about 165V. [93] On the contrary, when the ratio L1/L2 is equal to or more than 0.29, the firing voltage sharply rises to about 171V. This reason is that the total area of the scan electrode 102 or the sustain electrode 103 excessively decreases and thus an electrical resistance sharply increase. [94] Considering the description of FIGs. 7 to 9, the ratio L1/L2 of the width Ll of the hole 300 in the drection substantially parallel to the address electrode to the width L2 of the scan electrode 102 or the sustain electrode 103 in the direction substantially parallel to the address electrode may lie substantially in a range between 0.067 and

0.267 or 0.12 and 0.21 so as to reduce the dscharge current and maintain the firing voltage at a proper voltage level. [95] FIG. 10 is a table showing a discharge current flowing in the scan electrode or the sustain electrode and an electrical resistance of the scan electrode or the sustain electrode while a ratio S2/S1 of a sum S2 of the areas of the scan and sustain electrodes to the total area Sl of the front substrate changes from 0.30 to 0.78 by adjusting the width of the scan and sustain electrodes in a state where the total area of the front substrate is constant. [96] In FIG. 10, ® indcates that a panel state is excellent because the dscharge current or the electrical resstance is sufficiently small; O indcates that a panel state is good; and X indicates that a panel state is bad because the discharge current or the electrical resistance are excessively large.

[97] As shown in FIG. 10, first, in the aspect of the discharge current, when the ratio

S2/S1 changes from 0.30 to 0.52, the discharge current is sufficiently small and thus the panel state is excellent (©). Because the sum S2 of the areas of the scan and sustain electrodes is sufficiently smaller than the total area S 1 of the front substrate.

[98] When the ratio S2/S1 is 0.56, the discharge current is properly small, and thus the panel state is good (O).

[99] When the ratio S2/S 1 changes from 0.66 to 0.78, the discharge current sharply increases and thus the panel state is bad (X). Because the sum S2 of the areas of the scan and sustain electrodes excesavely increases.

[100] Secondly, in the aspect of the electrical resstance, when the ratio S2/S1 is 0.30, the electrical resistance sharply increases and thus the panel state is bad (X) because the sum S2 of the areas of the scan and sustain electrodes is excesavely smaller than the total area Sl of the front substrate. In this case, because the electrical resstance of the scan electrode or the sustain electrode is excesavely large, the firing voltage between the scan and sustain electrodes may relatively rise. Hence, the driving efficiency may be reduced.

[101] When the ratio S2/S1 is 0.38, the electrical resistance of the scan electrode or the sustain electrode is proper, and thus the panel state is good (O).

[102] When the ratio S2/S 1 is equal to or more than 0.40, the electrical reastances of the scan electrode and the sustain electrode are sufficiently small and thus the panel state is excellent (©), because the sum S2 of the areas of the scan and sustain electrodes is sufficiently large.

[103] Considering the description of FIG. 10, the sum S2 of the areas of the scan and sustain electrodes may lie substantially in a range between 38% and 56% or 40% and 52% of the total area S 1 of the front substrate.

[104] FIG. 11 is a table showing a discharge current flowing in the scan electrode or the sustain electrode and a firing voltage between the scan and sustain electrodes while a ratio S4/S3 of a sum S4 of the areas of the scan and sustain electrodes insde one discharge cell to an area S3 of one discharge cell changes from 0.40 to 0.90 by adjusting the width of the scan and sustain electrodes in a state where the area of one discharge cell is fixed.

[105] In FIG. 11, ® indicates that a panel state is excellent because the discharge current or the firing voltage is sufficiently small; O indicates that a panel state is good; and X indicates that a panel state is bad because the discharge current or the firing voltage are excessively large.

[106] As shown in FIG. 11, first, in the aspect of the discharge current, when the ratio S4/S3 changes from 0.40 to 0.68, the discharge current is sufficiently small and thus the panel state is excellent (©). Because the sum S4 of the areas of the scan and sustain electrodes is sufficiently smaller than the area S3 of one discharge cell.

[107] When the ratio S4/S3 is 0.71, the discharge current is properly small, and thus the panel state is good (O).

[108] When the ratio S4/S3 changes from 0.82 to 0.90, the discharge current sharply increases and thus the panel state is bad (X). Because the sum S4 of the areas of the scan and sustain electrodes excessively increases.

[109] Secondly, in the aspect of the firing voltage, when the ratio S4/S3 changes from 0.40 to 0.50, the firing voltage sharply rises and thus the panel state is bad (X). Because the sum S4 of the areas of the scan and sustain electrodes inside one dscharge cell is excessively smaller than the area S3 of one discharge cell.

[110] When the ratio S4/S3 is 0.52, the firing voltage between the scan and sustain electrodes is proper, and thus the panel state is good (O).

[I l l] When the ratio S4/S3 is equal to or more than 0.56, the firing voltage between the scan electrode and the sustain electrode are sufficiently low and thus the panel state is excellent (©). Because the sum S4 of the areas of the scan and sustain electrodes is sufficiently large.

[112] Considering the description of FIG. 11 , the sum S4 of the areas of the scan and sustain electrodes may lie substantially in a range between 52% and 71% or 56% and 68% of the area S4 of one discharge cell.

[113] FIG. 12 is a diagram for explaining the arrangement of holes and projections.

[114] As shown in FIG. 12, a plurality of holes 801 to 805 formed in the first portion Wl of the transparent electrode may be spaced apart from each other at a substantially equal interval g4.

[115] As above, when an interval between the plurality of holes 801 to 805 is substantially constant, a substantially uniform discharge can occur between the scan electrode and the sustain electrode inside all the discharge cells. For instance, in case that an interval between the plurality of holes 801 to 805 is substantially constant, the amount and a distribution characteristic of wall charges formed between the scan electrode and the sustain electrode insde a discharge cell (A) may be substantially equal to the amount and a distribution characteristic of wall charges formed between the scan electrode and the sustain electrode inside a discharge cell (B). Hence, since a discharge characteristic inside the discharge cell (A) is substantially equal to a discharge characteristic inside the discharge cell (B), a discharge generated inside all the discharge cells can be uniform.

[116] When the interval g4 between the plurality of holes 801 to 805 is substantially constant, it is very easy to align the holes 801 to 805 in a drection horizontal to the front substrate and the rear substrate (ie., a travelling direction of the scan and sustain electrodes) in a coalescing process of the front substrate and the rear substrate. This reason is that the scan electrode and the sustain electrode can have an equal form even if the holes 801 are out of alignment in the horizontal drection in the coalescing process of the substrates.

[ 117] A plurality of projections 811 to 816 formed in the second portion W2 of the transparent electrode may be spaced apart from each other at a substantially equal interval g5.

[118] As above, when the interval g5 between the plurality of projections 811 to 816 is substantially constant, characteristics of a discharge generated inside all the dscharge cells can be further uniform. Further, it is very easy to align the plurality of projections in the horizontal direction.

[119] The plurality of holes 801 to 805 may have a substantially equal width L3 in the horizontal direction of the substrates. The plurality of projections 811 to 816 may have a substantially equal width L4 in the horizontal direction of the substrates. Hence, characteristics of a discharge generated insde all the discharge cells can be further uniform. Further, it is very easy to align the plurality of holes and the plurality of projections in the horizontal direction.

[120] FIGs. 13 and 14 show another form of hole.

[121] As shown in FIG. 13, a plurality of holes 910 to 905 may be arranged in a zigzag form. In this case, the plurality of holes 910 to 905 may be spaced apart from each other at a substantially equal interval.

[122] As shown in FIG. 14, a plurality of holes 910 may have a polygon shape such as a rectangular. Further, the plurality of holes 910 may have a shape with a curvature.

[123] As above, the shape and the arrangement of the holes of the transparent electrode may variously changed.

[124] FIG. 15 shows another form of projection.

[125] As shown in FIG. 15, a plurality of projections 1000 may have a shape with a curvature in an end thereof. [126] An etching process may be changed or a method for applying the ctrvatire to a photomask may be used to form the curvature in the end of the projection 1000.

[127] FIG. 16 is a diagram for explaining the disposition of a scan electrode and a sustain electrode.

[128] At least two scan electrodes of the plurality of scan electrodes may be successively positioned so as to be adjacent to each other.

[129] As shown in FIG. 16, when the two scan electrodes are successively positioned, a coupling effect between the two scan electrodes can be reduced during the drive of the panel. Hence, a noise and electromagnetic interference (EMI) can be reduced. Further, the amount of discharge current can be reduced due to a reduction in the coupling effect, and thus the driving efficiency can be improved.

[130] The two scan electrodes may be successively positioned, and then the two sustain electrodes may be successively positioned. In this case, the amount of discharge current can be further reduced.

[131] Since the plasma display panel according to the exemplary embodiment includes the scan electrode and the sustain electrodes each including the transparent electrode and the bus electrode and the transparent electrode includes the plurality of holes and the plurality of projections, the amount of discharge current can be reduced and the driving effϋency can be improved.

[132] The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the foregoing embodiments is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.

Claims

[ 1 ] A plasma display panel comprising : a front substrate on which a scan electrode and a sustain electrode are portioned substantially parallel to each other, the scan electrode and the sustain electrode each including a transparent electrode and a bus electrode, the transparent electrode including: a first portion including a plurality of holes; a second portion including a plurality of projections that project in a drection substantially parallel to the address electrode; and a third portion that is portioned between the first portion and the second portion and overlaps the bus electrode; a rear substrate on which an address electrode is positioned to intersect the scan electrode and the sustain electrode; and a barrier rib positioned between the front substrate and the rear substrate.

[2] The plasma dsplay panel of claim 1, wherein the first portion of the scan electrode faces the first portion of the sustain electrode at a predetermined distance therebetween in the center of the discharge cell.

[3] The plasma display panel of claim 1, wherein the plurality of holes are arranged in a drection substantially parallel to the bus electrode.

[4] The plasma dsplay panel of claim 3, wherein the plurality of holes are spaced apart from each other at a substantially equal interval.

[5] The plasma dsplay panel of claim 1, wherein the plurality of projections are arranged in a drection substantially parallel to the bus electrode.

[6] The plasma dsplay panel of claim 5, wherein the plurality of projections are spaced apart from each other at a substantially equal interval.

[7] The plasma dsplay panel of claim 1, wherein the barrier rib includes a first barrier rib positioned substantially parallel to the scan electrode and the sustain electrode, and a second barrier rib intersecting the first barrier rib, and the scan electrode and sustain electrodes are spaced apart from the first barrier.

[8] The plasma dsplay panel of claim 1, wherein a ratio of a width of the hole in a drection substantially parallel to the address electrode to a width of the scan electrode or the sustain electrode in the drection substantially parallel to the address electrode lies substantially in a range between 0.067 and 0.267.

[9] The plasma dsplay panel of claim 8, wherein the ratio of the width of the hole in the direction substantially parallel to the address electrode to the width of the scan electrode or the sustain electrode in the direction substantially parallel to the address electrode lies substantially in a range between 0.12 and 0.21.

[10] The plasma display panel of claim 1, wherein a sum of areas of the scan and sustain electrodes lies substantially in a range between 40% and 52% of the total area of the front substrate.

[11] The plasma display panel of claim 1, wherein a sum of areas of the scan and sustain electrodes lies substantially in a range between 56% and 68% of an area of the discharge cell.

[12] The plasma display panel of claim 1, wherein at least two scan electrodes are successively portioned to be adjacent to each other.

[13] A plasma display panel comprising : a front substrate on which a scan electrode and a sustain electrode are portioned substantially parallel to each other, the scan electrode and the sustain electrode each including a transparent electrode and a bus electrode, the transparent electrode including: a first portion including a plurality of holes; a second portion including a plurality of projections that project in a direction substantially parallel to the address electrode; and a third portion that is positioned between the first portion and the second portion and overlaps the bus electrode; a rear substrate on which an address electrode is positioned to intersect the scan electrode and the sustain electrode; and a barrier lib positioned between the front substrate and the rear substrate, the barrier rib including lead (Pb) equal to or less than 1,000 ppm (parts per million).

[14] The plasma display panel of claim 13, wherein an upper dielectric layer is positioned on the scan electrode and the sustain electrode, and the upper dielectric layer includes lead equal to or less than 1,000 ppm.

[15] The plasma display panel of claim 13, wherein a lower dielectric layer is positioned on the address electrode, and the lower dielectric layer includes lead equal to or less than 1 ,000 ppm.

[16] The plasma display panel of claim 13, wherein the first portion of the scan electrode faces the first portion of the sustain electrode at a predetermined distance therebetween in the center of the discharge cell.

[17] The plasma display panel of claim 13, wherein the plurality of holes are arranged in a drection substantially parallel to the bus electrode.

[18] The plasma display panel of claim 13, wherein the plurality of projections are arranged in a direction substantially parallel to the bus electrode.

[19] The plasma display panel of claim 13, wherein the barrier rib includes a first barrier rib positioned substantially parallel to the scan electrode and the sustain electrode, and a second barrier rib intersecting the first barrier rib, and the scan electrode and sustain electrodes are spaced apart from the first barrier.

[20] The plasma dsplay panel of claim 13, wherein at least two scan electrodes are successively positioned to be adjacent to each other.