KR100768207B1 - Plasma display panel - Google Patents

Abstract

The present invention is a first substrate; A second substrate spaced apart from and opposed to the first substrate; A partition wall partitioning a discharge space between the first substrate and the second substrate into a plurality of discharge cells; A phosphor layer applied in the discharge cells; A plurality of pairs of transparent electrode pairs extending long across the first substrate and corresponding to regions in which the phosphor layer is relatively thickly applied among the regions in each discharge cell; A plurality of pairs of bus electrode pairs extending longitudinally across the first substrate and extending in parallel to the transparent electrode to contact the transparent electrode; And a plurality of address electrodes extending longitudinally across the second substrate and intersecting the transparent electrode and the bus electrode, wherein a portion of the transparent electrode located toward the center of the discharge cell is from a center of the discharge cell. Provided is a plasma display panel that is bent in a distant direction.

Description

Plasma display panel {Plasma display panel}

1 is a view illustrating an arrangement structure of electrodes in a conventional plasma display panel.

FIG. 2 is a photograph showing a profile of light generated in each discharge cell of the plasma display panel shown in FIG. 1.

3 is a partially exploded perspective view showing a plasma display panel according to an embodiment of the present invention.

4 is a plan view illustrating an electrode arrangement structure of the plasma display panel illustrated in FIG. 3.

5 is a plan view illustrating an electrode arrangement structure of a plasma display panel according to another exemplary embodiment of the present invention.

Brief description of symbols for the main parts of the drawings

110: first substrate 111, 211: X-side transparent electrode

112, 212: Y-side transparent electrode 113, 213: X-side bus electrode

114, 214: Y-side bus electrode 115: first dielectric layer

116: protective layer 120: second substrate

121 and 221: address electrode 123: second dielectric layer

124 and 224 bulkhead 125 phosphor layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a plasma display panel capable of reducing unit light, facilitating low gradation expression, and improving discharge efficiency and aperture ratio.

Recently, a plasma display panel, which is attracting attention as a replacement for a conventional cathode ray tube display device, has a structure in which a phosphor having a predetermined pattern is formed between two substrates on which a plurality of electrodes are formed and a discharge gas is sealed. And a discharge voltage is applied and the phosphor is excited by the ultraviolet rays generated thereby to obtain a desired image.

The plasma display panel includes a barrier rib defining a discharge cell which is a space causing gas discharge between the first and second substrates facing each other and spaced apart from each other, and is charged and discharged in the discharge cells. And a discharge gas for generating a phosphor gas, a phosphor applied to a surface of the discharge cell, and a voltage applied thereto.

1 is a view illustrating an arrangement structure of electrodes in a conventional plasma display panel. In the first substrate (not shown), a pair of sustain electrodes causing sustain discharge extends long across the first substrate. The sustain electrode pair is composed of the transparent electrode pairs 11 and 12 and the bus electrode pairs 13 and 14. The pair of transparent electrodes 11, 12 extends long across the first substrate. Lower electrical conductivity of the transparent electrodes 11 and 12 is disposed under the transparent electrode pairs 11 and 12 by overlapping bus electrode pairs 13 and 14 with higher electrical conductivity than the transparent electrode pairs 11 and 12. Complement The address electrode 15 is disposed on the second substrate (not shown), and the address electrode 15 extends long across the second substrate, and the transparent electrode pairs 11 and 12 and the bus electrode pairs 13 and 14 are disposed. It is formed to intersect perpendicularly to. The electrodes 11, 12, 13, 14, and 15 are embedded by a dielectric layer (not shown).

When a pulse voltage is applied to the sustain electrode pair of the plasma display panel during the sustain discharge period, the pulse voltage is alternately applied to the X-side transparent electrode 11 and the Y-side transparent electrode 12 via the bus electrode pairs 13 and 14. When applied, a maintenance discharge occurs. In the plasma display panel, an ultraviolet light emitted from a discharge gas in a discharge cell during sustain discharge excites the phosphor to generate visible light, thereby realizing an image.

FIG. 2 is a photograph showing a profile of light generated in each discharge cell of the plasma display panel shown in FIG. 1. In the figure, the generated light profiles in the G discharge cells, the R discharge cells and the B discharge cells are shown. Here, the bright color portion formed at the edge of each discharge cell is a portion with high luminance. It can be seen that the luminance is higher in the outer portion than the center portion of each discharge cell. This is because the coating thickness of the phosphor is large on the outer portion of the discharge cell, that is, on the side of the partition wall forming the discharge cell.

However, the transparent electrode of the conventional plasma display panel shown in FIG. 1 is formed in a wide area except for a position corresponding to the side surface of the partition wall. Therefore, a large discharge cannot be generated around the partition wall in which much light emission occurs. In addition, since the ITO area is large, the unit light becomes large, which makes it difficult to express low gray levels.

In particular, this problem is more problematic in the recent trend in which the technology development direction of the plasma display panel shifts from improving the luminance to improving the image quality such as the improvement of the low gradation expression.

The present invention provides a plasma display panel which is formed to correspond to the sidewalls of each discharge cell and has a transparent electrode having a reduced area, thereby facilitating low gray scale expression and improving luminous efficiency.

The present invention is a first substrate; A second substrate spaced apart from and opposed to the first substrate; A partition wall partitioning a discharge space between the first substrate and the second substrate into a plurality of discharge cells; A phosphor layer coated in the discharge cell; A plurality of transparent electrode pairs extending along the first substrate and formed along a region in which the phosphor layer is relatively thick among regions in each of the discharge cells; And bus electrode pairs extending long across the first substrate and disposed to be in contact with the transparent electrode. A plasma display panel including a plurality of address electrodes extending longitudinally across the second substrate and intersecting the transparent electrode and the bus electrode.

The region in which the phosphor layer is thickly applied may be a side region of the partition wall. A portion of the transparent electrode may be formed along a side surface of the partition wall, and may have an annular shape in which openings are formed in portions corresponding to the respective discharge cells. Therefore, the area of the transparent electrode may be reduced to lower luminance, and the unit light may be reduced to improve the expressive power of low gray. And the area of the transparent electrode is reduced, the power consumption is reduced. In addition, since the transparent electrode is concentrated in a place where many phosphors are applied, a large amount of discharge around the partition wall may be generated, thereby obtaining large visible light. Therefore, the light emission efficiency is increased and the low gradation power is improved due to the low power consumption as a whole, thereby improving the quality of the plasma display panel.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 3 is a partially exploded perspective view showing a plasma display panel according to an embodiment of the present invention, Figure 4 is a plan view showing the electrode arrangement structure of the plasma display panel shown in FIG.

The plasma display panel according to the exemplary embodiment of the present invention illustrated in FIGS. 3 and 4 includes a front panel 100 and a rear panel 200. The first substrate 110 of the front panel 100 and the second substrate 120 of the rear panel 200 are spaced apart from each other to face each other. A sustain electrode pair including the bus electrode pairs 113 and 114 and the transparent electrode pairs 111 and 112 is formed below the first substrate 110. The sustain electrode pair extends across the first substrate 110. The first dielectric layer 115 is applied to the first substrate 110 to fill the sustain electrode pair. The protective layer 116 is formed on the first dielectric layer 115.

The address electrode 121 formed on the second substrate 120 extends long across the second substrate 120 and crosses the sustain electrode pair. The second dielectric layer 123 is applied to the second substrate 120 to fill the address electrode 121. A partition wall is formed between the first substrate 110 and the second substrate 120 to divide the discharge space into a plurality of discharge cells. Phosphor layers 125a, 125b, and 125c are coated inside the discharge cells.

The first substrate 110 and the second substrate 120 are spaced apart from each other to form a discharge space. The second substrate 120 uses a transparent glass material so that visible light passes therethrough. However, the protection scope of the present invention is not limited thereto, and the first substrate 110 may be configured to be transparent. In this case, a vacuum plasma (VUV) emitted from the excited discharge gas excites the phosphor layer 115, and a transmission type plasma display in which visible light generated from the phosphor layer is transmitted to the first substrate 110 is also protected by the present invention. Will belong to.

A plurality of sustain electrode pairs including a plurality of transparent electrode pairs 111 and 112 and a plurality of bus electrode pairs 113 and 114 are formed side by side on the first substrate 110 constituting the front panel 100. One transparent electrode pair 111 and 112 includes an X-side transparent electrode 111 and a Y-side transparent electrode 112 and is formed in a horizontal direction of the plasma display panel. The transparent electrodes 111 and 112 mainly include a transparent conductive material such as indium tin oxide (ITO) so that visible light can be easily transmitted. However, the transparent electrodes 111 and 112 have a large electrical resistance and thus have a large voltage drop, making it difficult to apply a constant driving voltage to all the discharge cells.

As shown in FIG. 4, the transparent electrodes 111 and 112 may be formed of an elongated extending part extending in the horizontal direction and a protrusion projecting toward the center of each discharge cell on the same plane from the extending part. In addition, although not shown in the drawing, the transparent electrodes 111 and 112 may have a much wider width than the bus electrodes 113 and 114 and extend in the horizontal direction.

The partition wall 124 forms a discharge space between the first substrate 110 and the second substrate 120 to form the discharge cells so that a basic unit of an image can be formed, and cross talk between the discharge cells. It has a role to prevent. As the partition wall 124, a matrix type partition wall 124 including a horizontal partition wall 124a and a vertical partition wall 124b may be used. The partition wall 124 forms a discharge space between the first substrate 110 and the second substrate 120 to form the discharge cells so that a basic unit of an image can be formed, and cross talk between the discharge cells. It has a role to prevent. In one embodiment of the partition wall 124, a partition wall 124 having a rectangular cross section is disclosed, but the present invention is not limited thereto, and includes a partition wall having a polygonal structure such as a hexagon or an octagon, or a cross section having a circular or oval shape. .

A rectangular opening 112a is formed in the protrusion of the transparent electrodes 111 and 112. As a result, the protrusions of the transparent electrodes 111 and 112 are formed along the side surfaces of the partition wall 124 and have a rectangular ring shape. The reason why the protrusion of the transparent electrode is formed along the side surface of the partition wall 124 is that the phosphor is thickly coated on the side surface of the partition wall 124 in the process of forming the phosphor. Therefore, the shape of the transparent electrode may vary depending on the shape of the partition wall 124, that is, polygon or circle. Even in this case, the shape of the transparent electrode may be a polygonal or circular ring shape formed along the side surface of the partition wall 124. The width of the portion of the ring-shaped transparent electrode can be appropriately determined in consideration of the aperture ratio, luminous efficiency, luminance, and the like, which will be described later.

As described above, the shape of the transparent electrode can reduce the area of the transparent electrode. Therefore, as the luminance is lowered, the unit light is reduced to improve the expressive power of the low gradation. And the area of the transparent electrode is reduced, the power consumption is reduced. In addition, since the transparent electrode is concentrated in a place where many phosphors are coated, a large amount of discharge around the partition wall 124 may be generated, thereby obtaining large visible light. Therefore, the light emission efficiency is increased and the low gradation power is improved due to the low power consumption as a whole, thereby improving the quality of the plasma display panel.

In addition, a portion of the X-side transparent electrode positioned at the center of the discharge cell may be curved 111b and 112b in a direction away from the center of the discharge cell. In this case, similarly, the portion of the Y-side transparent electrode located toward the center of the discharge cell is also bent 111b and 112b in a direction away from the center of the discharge cell. Therefore, the gap between the X-side transparent electrode and the Y-side transparent electrode is longer than that corresponding to both sides of the discharge cell at the portion corresponding to the center of the discharge cell. That is, a long gap and a short gap are employed. This occurs because the sustain discharge initiated in the short gap during the sustain discharge period is diffused into the long gap, thereby increasing the discharge space, thereby increasing the discharge efficiency. However, the plasma display panel of the present invention does not necessarily need to adopt such a long gap and short gap structure.

On the other hand, the bus electrodes 113 and 114 are arranged to be electrically connected to the transparent electrodes 111 and 112 to compensate for the low electrical conductivity of the transparent electrodes 111 and 112. One bus electrode pair 113 and 114 is composed of an X-side bus electrode 113 and a Y-side bus electrode 114. The bus electrodes 113 and 114 are opaque metal electrodes having good electrical conductivity. The material of the bus electrodes 113 and 114 is not particularly limited, but may include an opaque metal material including components such as Cr-Cu-Cr and Ag having good electrical conductivity. The bus electrodes 113 and 114 are disposed to overlap the extension portions of the transparent electrodes 111 and 112. Thus, the pulse signal applied to the sustain electrode is applied to the transparent electrodes 111 and 112 located inside the discharge cell through the bus electrodes 113 and 114. The width of the bus electrodes 113, 114, 213, and 214 should be appropriately designed in consideration of the possibility of manufacturing process, the size of the horizontal partition wall 124a, and the prevention of short circuit.

As shown in FIG. 4, the bus electrodes 113 and 114 are disposed more oriented toward the center of the discharge cell than the horizontal partition wall 124a formed in the left and right directions of the plasma display panel. That is, the extension portions of the bus electrodes 113 and 114 and the transparent electrodes 111 and 112 are located inside the discharge cells. However, the bus electrodes 113 and 114 may be formed into the discharge cell while overlapping a portion of the horizontal partition wall 124a.

In contrast, as illustrated in FIG. 5, the bus electrodes 213 and 214 may be located on the horizontal partition wall 224a. 5 is a plan view showing an electrode arrangement structure of a plasma display panel according to another embodiment of the present invention having a double partition structure. The double barrier rib structure is a structure in which non-discharge cells in which discharge does not actually occur exist in upper and lower portions of discharge cells adjacent in the horizontal direction. In other words, the horizontal partition wall 224a of the discharge cell is doubled. At this time, since the size of the non-discharge cell is much smaller than the size of the discharge cell, it does not substantially affect the resolution. In the plasma display panel having the double barrier rib structure, the bus electrodes 213 and 214 may be positioned on the horizontal barrier rib 224. That is, the extension portions of the bus electrodes 213 and 214 and the transparent electrodes 211 and 212 are not positioned in the discharge space of the discharge cell.

In addition, in the case of the plasma display panel having the double barrier rib 224, the opaque bus electrodes 213 and 214 are positioned on the horizontal barrier rib 224a, thereby reducing the aperture ratio of the discharge cell and reducing the external light reflection luminance. You can get it. In the case of the plasma display panel shown in FIG. 4 that does not use the double partition wall, a black stripe (not shown) may be disposed on the partition wall 124 in order to reduce external light reflection luminance.

The first dielectric layer 115 is coated on the first substrate 110 to fill the sustain electrode pairs 111, 112, 113, 114, 211, 212, 213, and 214. The first dielectric layer 115 is an insulator, and acts as a capacitor when discharging. In addition, it plays a role of limiting current and performs a memory function by forming wall charge. When visible light generated in the discharge cell passes through the first substrate 110 to form an image, the first dielectric layer 115 should use a material having good light transmittance.

The protective layer 116 is coated on the first dielectric layer 115. The protection layer 116 facilitates discharge by increasing the emission of secondary electrons during discharge, and protects the surface of the first dielectric layer 115 to prevent the lifespan of the sustain electrode pairs 111, 112, 113, 114, 211, 212, 213, and 214 from decreasing. The protective layer 116 should be made of a material that requires high permeability, sputtering resistance, low discharge voltage, wide memory margin and drive voltage stability. In one embodiment, magnesium oxide (MgO) may be used.

A plurality of address electrodes 121, 122, 221, and 222 extends long across the plasma display panel and crosses the sustain electrodes 111, 112, 113, 114, 211, 212, 213, and 214 on the second substrate 120 constituting the rear panel 20. A second dielectric layer 123 is formed on the second substrate 120 to fill the address electrode 121. The second dielectric layer 123 performs a function similar to that of the first dielectric layer 115. Then, the second dielectric layer 123 is formed in the discharge cell. When the visible light is transmitted to the first substrate 110, the second dielectric layer 123 does not need to be made of a transparent material, but may be made of a material capable of reflecting the visible light to the first substrate 110. However, when visible light is transmitted to the second substrate 120 side, the second dielectric layer 123 should be made of a transparent material .. The partition wall partitioning the discharge space to form the discharge cells 14 on the second dielectric 123. (124, 224) It is made.

R, G, and B phosphors 125a, 125b, and 125c are sequentially applied in each discharge cell. The phosphor layer 125 may be applied to the inner wall and the bottom of the discharge cell partitioned by the partition walls 124 and 224, but is not limited thereto. When discharge occurs, the photoluminescence (PL) light emitting mechanism occurs in the phosphor layer 125. The PL light emitting mechanism is a mechanism in which vacuum ultraviolet rays generated by discharge excite electrons of the phosphor and emit visible light when the excited electrons become stable again.

As the R phosphor 125a, Y _0.66 Gd _0.35 BO ₃ : Eu ₃ , Y ₂ O ₃ : Eu, GdBO ₃ : Eu, or the like can be used. As the G phosphor 125b, Zn ₂ SiO ₄ : Mn, BaAl ₁₂ O ₁₉ : Mn, YBO ₃ : Tb, or the like can be used. As the B phosphor 125c, BaMgAl ₁₀ O ₁₇ : Eu ²⁺ or the like can be used.

Meanwhile, after the first substrate 110 and the second substrate 120 are bonded to each other, the assembled plasma display panel interior space is filled with air. Therefore, the air in the assembled plasma display panel is completely exhausted and filled with an appropriate discharge gas capable of increasing discharge efficiency. As the discharge gas, a mixed gas such as Ne-Xe, He-Xe, He-Ne-Xe, etc. may be used.

During the sustain discharge, ultraviolet rays are generated while the excited discharge gas is stabilized in each discharge cell, and the ultraviolet rays excite the respective R, G, and B phosphors 125 applied to each discharge cell. Accordingly, in each discharge cell, the red visible light, the green visible light, and the blue visible light generated by the excited phosphor 125 are transmitted through each of them to form one pixel. These pixels are gathered to form an image.

The plasma display panel of the present invention can reduce the unit light by facilitating low gradation by providing a transparent electrode having a reduced area. In addition, the luminous efficiency can be improved by reducing power consumption and increasing the aperture ratio.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (8)

A first substrate; A second substrate spaced apart from and opposed to the first substrate; A partition wall partitioning a discharge space between the first substrate and the second substrate into a plurality of discharge cells; A phosphor layer applied in the discharge cells; A plurality of pairs of transparent electrode pairs extending long across the first substrate and corresponding to regions in which the phosphor layer is relatively thickly applied among the regions in each discharge cell; A plurality of pairs of bus electrode pairs extending longitudinally across the first substrate and extending in parallel to the transparent electrode to contact the transparent electrode; And A plurality of address electrodes extending across the second substrate and intersecting the transparent electrode and the bus electrode; And a portion of the transparent electrode positioned at the center of the discharge cell is curved in a direction away from the center of the discharge cell. According to claim 1, The region in which the phosphor layer is thickly coated is a side region of the partition wall. According to claim 1, A portion of the transparent electrode is formed to correspond to the side of the partition wall, the plasma display panel, the opening is formed in each portion corresponding to each discharge cell of the transparent electrode. delete According to claim 1, The bus electrode is disposed to overlap with the bottom of the transparent electrode side by side. The method of claim 5, And the bus electrode is disposed at a position corresponding to a discharge space in the discharge cell. The method of claim 6, And the bus electrode is disposed such that at least a portion of the bus electrode overlaps the portion corresponding to the partition wall. According to claim 1, A first dielectric layer applied to the first substrate to fill the transparent electrode pair and the bus electrode pair; A protective layer applied on the first dielectric layer; And And a second dielectric layer applied to the second substrate to fill the address electrodes.

Images