KR20050100105A - Plasma display panel - Google Patents

Abstract

An object of the present invention is to provide a plasma display panel having a structure in which the aperture ratio of a front substrate is significantly improved, permanent afterimages are not generated, and edge curls are not generated. A substrate, a rear substrate disposed in parallel with the front substrate, a front cell and a rear substrate disposed between the front substrate and the rear substrate, defining a light emitting cell together with the front substrate and the rear substrate, and a front partition wall formed of a dielectric, a horizontal portion, a vertical portion, and A rear partition disposed between the front discharge electrode and the rear discharge electrode, which is spaced apart from each other, is disposed in the front partition wall to connect the horizontal part and the vertical part, and has a corner part with an inner surface rounded therebetween, and spaced apart from each other. And a plasma layer having a phosphor layer disposed in a space defined by the rear partition wall, and a discharge gas in the light emitting cell. It provides a ray panel.

Description

Plasma display panel {Plasma display panel}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel that uses a gas discharge to express characters or images, and more particularly, to a plasma display panel having an enlarged surface on which a discharge occurs.

Recently, a device employing a plasma display panel as a flat panel display device has a large screen and has excellent characteristics of high definition, ultra-thin, light weight, and wide viewing angle, and is easier to manufacture than other flat panel display devices. It is attracting attention as a large flat panel display device.

The plasma display panel is classified into a direct current (DC) type, an alternating current (AC) type, and a hybrid type according to an applied discharge voltage, and classified into a counter discharge type and a surface discharge type according to a discharge structure.

In the DC plasma display panel, all electrodes are exposed to a discharge space, and charges are directly transferred between the corresponding electrodes. In the AC plasma display panel, at least one electrode is surrounded by a dielectric layer, and discharge is performed by an electric field of wall charge instead of direct charge transfer between the corresponding electrodes.

In the DC plasma display panel, since the charge is directly transferred between the corresponding electrodes, there is a problem in that the electrode is severely damaged. In recent years, an AC plasma display panel having an AC type, in particular, a three-electrode surface discharge structure is present. This has been generally employed.

The conventional surface discharge plasma display panel 10 including the AC three-electrode surface discharge plasma display panel includes a front substrate 20 and a rear substrate 30 as shown in FIG. 1.

The back substrate 30 includes an address electrode 33 for generating an address discharge, a back dielectric layer 35 embedding the address electrode, a partition wall 37 partitioning the light emitting cells, and both sides of the partition wall and the partition wall. The phosphor layer 39 applied to the back substrate which is not formed is formed.

The front substrate 20 disposed to be spaced apart from and opposed to the rear substrate may include X and Y electrodes 40 and 50 for generating a sustain discharge, and a front dielectric layer 25 with the X and Y electrodes 40 and 50 embedded therein. ) And a protective film 29.

By the way, in the conventional plasma display panel, the transparent X electrode 40a and the bus X disposed on one side of the transparent X electrode on the front substrate 20 through which visible light emitted from the phosphor layer 39 in the discharge space passes. The Y electrode 50 normally provided with an electrode 40b, the Y electrode 50 with a transparent Y electrode 50a, and a bus Y electrode 50b disposed on one side of the transparent Y electrode 50a; The front dielectric layer 25 and the passivation layer 29 are sequentially formed on the X and Y electrodes. These factors have a serious problem that the visible light transmittance of about 60%.

In addition, in the conventional surface discharge plasma display panel 10, the electrode which causes the discharge is formed on the upper surface of the discharge space, that is, the inner surface of the front substrate 20 through which visible light passes, and the discharge is generated on the inner surface and diffused. Therefore, there is an inherent problem of low luminous efficiency.

Furthermore, in the conventional surface discharge plasma display panel 10, when the particles are used for a long time, the charged particles of the discharge gas cause ion sputtering on the phosphor by an electric field, causing permanent afterimage.

SUMMARY OF THE INVENTION The present invention is to solve the above problems, to provide a plasma display panel that can significantly expand the opening area and transmittance as compared to the conventional plasma display panel, and can significantly expand the discharge area by greatly expanding the discharge surface. .

Another object of the present invention is to provide a plasma display panel capable of low voltage driving, significantly improving luminous efficiency, and drastically reducing permanent afterimage phenomenon.

Still another object of the present invention is to provide a plasma display panel having a structure in which the space charge of the plasma can be efficiently used and the edge curl phenomenon is reduced by concentrating the plasma by the discharge to a predetermined portion of the discharge space, for example, the center portion. .

In order to achieve the above object, the present invention is:

Transparent front substrate;

A rear substrate disposed in parallel with the front substrate;

A front partition wall disposed between the front substrate and the rear substrate and defining a light emitting cell together with the front substrate and the rear substrate and formed of a dielectric;

A front discharge electrode and a rear discharge electrode disposed in the front partition wall so as to surround the light emitting cell and having a horizontal portion, a vertical portion, and a corner portion having an inner surface rounding the horizontal portion and the vertical portion;

A rear partition wall disposed between the front partition wall and the rear substrate;

A phosphor layer disposed in a space defined by the rear partition wall; And

It provides a plasma display panel having a discharge gas in the light emitting cell.

The inner surface of the corner portion is preferably rounded with a radius of curvature of 5% to 50% of the distance between the horizontally neighboring front bulkhead centers.

Here, it is preferable that the partition edges corresponding to the inner surface of the corners of the front partitions are rounded, and in this case, the partition edges are rounded with the same radius of curvature as the corners.

On the other hand, at least one of the corners may be provided with a rounded outer surface connecting the horizontal outer surface and the vertical outer surface, in this case, the outer surface of the corner portion, the front partition neighboring the horizontal It is preferred to round to a radius of curvature of 5% to 50% of the center-to-center distance.

The front discharge electrode may extend along one row of light emitting cells, and the rear discharge electrode may extend along another row of light emitting cells that intersect the row of light emitting cells.

Alternatively, the front discharge electrode and the rear discharge electrode may further include parallel address electrodes extending along one row of light emitting cells, and extend along the other row of light emitting cells crossing the row of light emitting cells. In this case, the address electrodes are disposed between the rear substrate and the phosphor layer, and a dielectric layer is disposed between the address electrodes and the phosphor layer.

At least the side surface of the front bulkhead is preferably covered by a protective film.

The front bulkhead and the rear bulkhead may be integrally formed.

Next, a plasma display panel according to a preferred embodiment of the present invention will be described in detail with reference to the drawings.

2 and 3, the plasma display panel 100 according to the embodiment of the present invention includes a front substrate 120, a front discharge electrode 140, a rear discharge electrode 150, and a rear substrate 130. ), A front partition 127, a rear partition 137, a phosphor layer 139, and a discharge gas (not shown).

The transparent front substrate 120 is disposed in parallel with the rear substrate 130 so that visible light passes and the image is projected. The front partition 127 is formed between the front substrate and the rear substrate. The front partition 127 is disposed in the non-discharge unit to partition the light emitting cell (C). In the front partition wall, the front discharge electrode 140 and the rear discharge electrode 150 are formed to surround the light emitting cell.

A rear partition 137 is formed between the front bulkhead 127 and the rear substrate 130, and the rear partition 137 functions to prevent crosstalk of charged particles. In this case, the front bulkhead and the rear bulkhead may be integrally formed.

The phosphor layer 139 is disposed in the space defined by the rear partition 137. Discharge gas (not shown) exists in the light emitting cell.

The front discharge electrode 140 and the rear discharge electrode 150 may be disposed to cross each other. That is, the front discharge electrode 140 may extend along one row of light emitting cells C, and the rear discharge electrode 150 may extend along another row of light emitting cells crossing the column of light emitting cells. One of the front discharge electrode 140 and the rear discharge electrode 150 may serve as an address electrode causing an address discharge and a sustain electrode causing a sustain discharge.

In contrast, the front discharge electrode 140 and the rear discharge electrode 150 extend in one direction in parallel to each other, and the address electrodes 133 are formed to intersect the front discharge electrode 140 and the rear discharge electrode 150. Can be extended. In this case, the side surface 127s of the front partition wall is covered by the passivation layer 129, and the address electrodes 133 are disposed between the rear substrate 130 and the phosphor layer 139, and the address electrode 133 is disposed. It is preferable that the dielectric layer 135 is formed between the layers and the phosphor layer 139.

The back substrate 130 supports the address electrodes 133, the dielectric layer 135, and the like, and is typically made of a material mainly composed of glass.

The address electrodes 133 are used to generate an address discharge for facilitating a sustain discharge between the rear discharge electrode 150 and the front discharge electrode 140. More specifically, the sustain discharge start voltage at which the sustain discharge starts. It serves to lower.

Here, the address discharge is a discharge occurring between the rear discharge electrode 150 and the address electrode 133. When the address discharge is completed, cations are accumulated on the rear discharge electrode 150 and electrons are accumulated on the front discharge electrode 140 side. As a result, the sustain discharge between the rear discharge electrode and the front discharge electrode becomes easier.

 In the present embodiment, the front discharge electrode 140 and the rear discharge electrode 150 are arranged to surround the upper side of the light emitting cell (C). The upper side of the light emitting cell means a portion higher than the phosphor layer 139 formed on the rear partition 137.

In FIG. 2, the rear discharge electrode 150 and the front discharge electrode 140 are each formed as one electrode. Alternatively, the rear discharge electrode 150 and the front discharge electrode may have two or more sub-electrodes, respectively.

The dielectric layer 135 is formed as a dielectric that can induce charge while preventing cations or electrons from colliding with the address electrode 133 during discharge, and inducing charge. Such dielectrics include PbO, B ₂ O ₃ , and the like. SiO ₂ and the like.

The rear partition 137 prevents mis-discharge between light emitting cells C corresponding to one of the red light emitting pixel, the green light emitting subpixel, and the blue light emitting subpixel constituting the unit pixel.

In FIG. 2, the rear partition 137 divides the light emitting cells into a matrix, but is not limited thereto. The rear partition 137 may be partitioned into other shapes such as a honeycomb. In addition, although the cross section of the light emitting cell C defined by the rear partition 137 is illustrated in FIG. Can be.

If the address electrode 133 is provided in the plasma display panel 100, the rear discharge electrode 150 and the front discharge electrode 140 are electrodes for sustain discharge, and implement an image of the plasma display panel between the electrodes. Maintenance discharge occurs. The rear discharge electrode 150 and the front discharge electrode 140 is preferably formed of a conductive metal such as aluminum, copper, silver, or the like. The extension of the rear discharge electrode 150 to intersect the address electrode means that the columns of the light emitting cells C through which the address electrodes pass and the columns of the light emitting cells C through which the rear discharge electrodes pass. to be. In addition, the front discharge electrode 140 extends in parallel with the rear discharge electrode 150, which means that the front discharge electrode is disposed together with a predetermined distance from the rear discharge electrode.

The front partition wall 127 partitions adjacent light emitting cells C, and is formed of a dielectric material to prevent the rear discharge electrode 150 and the front discharge electrode 140 from being directly energized during sustain discharge. It directly prevents the electrodes 140 and 150 from damaging them and induces charged particles to accumulate wall charges.

The front partition 127 is preferably covered by a protective film 129. The protective layer 129 is not an essential component, but is preferably formed because charged particles collide with the front partition 127 to prevent damage to the front partition and emit a large amount of secondary electrons during discharge.

The phosphor layer 139 includes a component that emits visible light by receiving ultraviolet rays emitted by the sustain discharge, and the phosphor layer formed on the red light emitting subpixel includes phosphors such as Y (V, P) O ₄ : Eu. The phosphor layer formed on the green light emitting subpixel includes phosphors such as Zn ₂ SiO ₄ : Mn, YBO ₃ : Tb, and the like, and the phosphor layer formed on the blue light emitting subpixel includes phosphors such as BAM: Eu.

As the discharge gas charged in the light emitting cell, a penning mixture such as Xe-Ne, Xe-He, Xe-Ne-He, etc. is used. The reason why Xe is used as the main discharge gas is that because Xe is a chemically stable inert gas, it is not dissociated due to discharge, but because the atomic number is large, the excitation voltage is lowered and the wavelength of light emitted is increased. to be. The reason for using He or Ne as a buffer gas is because the voltage reduction effect due to the panning effect due to Xe and the sputtering effect due to the high pressure are reduced.

The front substrate 120 is made of a material having good light transmittance such as glass. The light emitting cell C of the front substrate 120 includes a transparent X electrode 40a and a transparent Y electrode formed of an indium tin oxide (ITO) film existing on the front substrate of the conventional plasma display panel shown in FIG. 1. 50a, the bus X electrode 40b and the bus Y electrode 50b formed of metal, the front dielectric layer 27 covering the electrodes 40a, 40b, 50a, and 50b, and the protective film 29 do not exist. The forward transmittance of visible light is remarkably improved from 60% to about 90% of the conventional one. Therefore, when the image is implemented with the luminance of the conventional level, the electrodes 140 and 150 are driven at a relatively low voltage, thereby improving luminous efficiency.

In this case, the front discharge electrode 140 and the rear discharge electrode 150 serving as the X electrode and the Y electrode, respectively, are not disposed on the front substrate 120 through which visible light is transmitted, but are disposed on the side of the discharge space. Since a low resistance electrode such as a metal electrode can be used as a discharge electrode without using a transparent electrode having a high resistance as a discharge electrode, the discharge response speed is increased and low voltage driving can be performed without distortion of the waveform.

Here, the front discharge electrode 140 and the rear discharge electrode 150, as shown in Figure 4, the horizontal portion 143, 153, vertical portion 147, 157 and the corner portion 145, 155, respectively Equipped. 2 to 4, the horizontal parts 143 and 153 indicate electrodes formed in a direction crossing the address electrode 133, and the vertical parts 147 and 157 are parallel to the address electrode 133. Points to electrodes formed in one direction.

In the present invention, the inner surfaces 145 'and 155' of the corner portions 145 and 155 connecting the horizontal portion and the vertical portion are rounded. This is to prevent edge curl from occurring at the corners 145 and 155, to prevent abnormal discharge in the light emitting cell, and to concentrate the electric field on the center of the light emitting cell. 4 and 5, during the manufacturing process of the front discharge electrode 140 and the rear discharge electrode 150, which is usually formed of a conductive metal material such as aluminum, copper, silver, etc., drying, exposure, development and It has a process of baking.

For example, a method of manufacturing the front discharge electrode 140 and the rear discharge electrode 150 by a photolithography method using an Ag photosensitive paste of a conductive metal is described by applying an Ag photosensitive paste by printing or the like. To form. Next, a drying process is performed in order to lose a solvent from the Ag photosensitive paste layer thus formed.

Next, by irradiating an ultraviolet-ray through a photomask, an exposed part and a non-exposed part are formed in the Ag photosensitive paste layer corresponding to an electrode pattern. This exposed portion then becomes a pattern of the bus electrodes.

Next, the exposed portion is fixed in the front partition by developing, and then the firing is performed so that the entire electrode firing becomes the front discharge electrode 140 or the rear discharge electrode 150.

As described above, when patterning is performed by the photolithography method using the conductive metal photosensitive paste, a firing process must be performed to dissipate the resin component in the paste, and edge-curl is generated in this process. That is, a binder, which combines a solvent and a conductive metal photosensitive paste during firing, flows out due to high heat, and due to the tensile force (surface tension) during heating, parts except corners are contracted and edges are rolled up. The edge curl Ec is generated by going.

When such an edge curl Ec occurs, it is difficult to form a dielectric layer on the upper portion, and the surface angle of the edge portion after firing is sharpened, so that the portion where the edge curl has occurred during the dielectric formation process does not form an accurate dielectric pattern.

In addition, as shown in FIG. 5, if edge curls Ec occur on the inner side surfaces 145 ′ and 155 ′ of the edges, edge curls are formed when the panel is driven to concentrate an electric field on a sharp portion. The portion corresponding to the edge curl becomes relatively smaller in thickness than the thickness K ″ of the other portion of the dielectric thickness K '. This causes the front bulkhead 127 corresponding to the edge curl Ec to be insulated and destroyed. Due to the electric field concentration and dielectric breakdown, the wall charge behavior of the light emitting cells corresponding to the corners 145 and 155 at the time of discharge becomes different from the set behavior shape, thereby causing abnormal discharge. The electric field concentration is not smoothed to the center of the light emitting cell, and the discharge volume is reduced, resulting in a decrease in light efficiency.

Therefore, as illustrated in FIG. 4, it is preferable that the inner surfaces 145 ′ and 155 ′ of the corner portions are rounded so that edge curls are not generated on the inner surfaces of the front discharge electrodes and the rear discharge electrodes.

In this case, the inner surfaces 145 ′, 155 ′ of the corner portions are preferably rounded with a radius of curvature α1 of 5% to 50% of the distance P between the transversely neighboring forward bulkhead centers. When the inner surface is formed with a radius of curvature of less than 5%, the rounding degree of the corner portion is too small to prevent the occurrence of edge curl, and because the electric field is not concentrated at the center of the light emitting cell, 50% This is because the portion where the round meets becomes another corner when it exceeds.

When the inner surface of the corner portion is rounded, it is preferable that the partition edge portion 127 ′ of the front bulkhead corresponding thereto is rounded. As a result, the separation distances between the corner portions 145 'and 155' and the partition edge portion 127 'are substantially the same in all aspects, so that the discharge can be evenly generated in the entire light emitting cell.

Therefore, more preferably, the partition edge portion 127 ′ has a curvature radius α2 equal to the radius of curvature α1 rounded by the corner portion so that the edge portion of the electrode and the partition edge portion of the front partition wall have a constant separation distance. ) Is rounded.

6 and 7, the front discharge electrode 240 and the rear discharge electrode 250 have separate horizontal portions 243 and 253 and vertical portions 247 for at least one light emitting cell C. FIG. , 257, and the edges 245 and 255 may surround the light emitting cell.

That is, as illustrated in FIG. 7, each light emitting cell includes separate horizontal parts 243 and 253, vertical parts 247 and 257, and corner parts 245 and 255 connecting the horizontal parts and the vertical parts. The connection part 260 may be provided between the adjacent vertical parts. In addition, unlike FIG. 7, a separate horizontal part, vertical part, and corner part may be formed for each of two or more light emitting cells.

In this case, as illustrated in FIG. 7, the horizontal outer surfaces 243 ″ and 253 ″ and the vertical outer surfaces 247 ″ and 257 ″ may be connected as well as the inner side surfaces 245 ′ and 255 ′ of the corner portions. It is preferable that the outer side surfaces 245 ", 255" of the corners are rounded.

If the outer surfaces 245 "and 255" of the corner portion of the front discharge electrode and the rear discharge electrode having such a structure are not rounded, the outer surfaces 245 "and 255" of the corner portion are sharp as shown in FIG. Since the edges have edges, edge curls Ec are generated on the outer surface during the manufacture of the front discharge electrode and the rear discharge electrode.

As a result, the dielectric layer is hardly formed on the upper portion, and the surface angle of the edge portion after firing is sharpened, so that the portion in which the edge curl has occurred during the dielectric formation process does not form an accurate dielectric pattern.

Therefore, it is preferable that the front discharge electrodes and the rear discharge electrodes outer surfaces 245 "and 255" are also rounded together with the inner surfaces 245 'and 255'.

In this case, the outer surface of the corner portion is preferably a radius of curvature α3 of 5% to 50% of the distance between the horizontally neighboring front bulkhead centers. This radius is the minimum radius of curvature to prevent the occurrence of edge curl on the outer surface. When the radius of curvature of the outer surface is formed with a radius of curvature of less than 5% of the distance between the longitudinal sections forming the light emitting cells, The rounding degree is too small to prevent the occurrence of edge curl, because the electric field is not concentrated in the center of the light emitting cell, and if it exceeds 50%, another corner is formed at the part where the round meets. to be.

According to the plasma display panel having the above structure, first, since there is no other element other than the substrate in the portion of the front substrate through which visible light passes, the aperture ratio can be significantly improved, and the transmittance can be improved at 60% or less. Up to about 90%.

In addition, since the edge curl does not occur during the manufacture of the front discharge electrode and the rear discharge electrode, the electric field can be concentrated in the center and no abnormal discharge occurs, thereby increasing the luminous efficiency.

In addition, as the structure of the plasma display panel is drastically changed as compared with the related art, the discharged surface and the discharge area are greatly enlarged, and the amount of plasma is greatly increased to emit a lot of ultraviolet rays, the luminance is increased, and the low voltage driving is performed. This makes it possible to increase the luminous efficiency.

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.

1 is an exploded perspective view showing a conventional plasma display panel;

2 is an exploded perspective view showing a plasma display panel according to an embodiment of the present invention,

3 is a cross-sectional view taken along line III-III of FIG. 2,

4 is a cross-sectional view taken along line IV-IV of FIG. 3,

5 is a cross-sectional view taken along the line VV of FIG. 4,

6 is a modification of FIG. 2,

7 is a modification of FIG. 4,

8 is a cross-sectional view taken along the line VII-VII of FIG. 7.

Explanation of symbols on main parts of drawing

100: plasma display panel 120: front substrate

127: forward bulkhead 129: shield

130: rear substrate 133: address electrode

135: dielectric layer 137: rear partition

139: phosphor layer 140, 240: front discharge electrode

143, 153, 243, 253: Horizontal part 145, 155, 245, 255: Corner part

145 ', 155', 245 ', 255': inner side of corner

147, 157, 247, 257: vertical portion 150, 250: rear discharge electrode

245 ", 255": corner outer side 155 ": C; light emitting cell

Ec: edge curl α1: inside curvature radius

α2: curvature half of horizontal edge portion α3: radius of curvature of the outer surface

Claims (11)

Transparent front substrate; A rear substrate disposed in parallel with the front substrate; A front partition wall disposed between the front substrate and the rear substrate and defining a light emitting cell together with the front substrate and the rear substrate and formed of a dielectric; A front discharge electrode and a rear discharge electrode disposed to be spaced apart from each other in a front partition wall to include a horizontal portion, a vertical portion, and a corner portion having a horizontal portion connected to the horizontal portion and a rounded inner surface to surround the light emitting cell; A rear partition wall disposed between the front partition wall and the rear substrate; A phosphor layer disposed in a space defined by the rear partition wall; And And a discharge gas in the light emitting cell. The method of claim 1, And the inner surface of the corner portion is rounded with a radius of curvature of 5% to 50% of the distance between the horizontally adjacent front bulkhead centers. The method of claim 1, And a partition edge portion of the front partition corresponding to the inner surface of the corner portion is rounded. The method of claim 3, wherein And the partition edges are rounded at the same radius of curvature as the corners. The method of claim 1, And at least one of the corner portions has a rounded outer surface connecting the horizontal outer surface and the vertical outer surface. The method of claim 5, And an outer surface of the corner portion is rounded with a radius of curvature of 5% to 50% of a distance between the horizontally adjacent front bulkhead centers. The method of claim 1, Wherein the front discharge electrode extends along one row of light emitting cells, and the rear discharge electrode extends along another row of light emitting cells that intersect the row of light emitting cells. The method of claim 1, The front discharge electrode and the rear discharge electrode extend in parallel to each other along a row of light emitting cells, And an address electrode extending along light emitting cells of another row crossing the light emitting cells. The method of claim 8, And the address electrodes are disposed between the rear substrate and the phosphor layer, and a dielectric layer is disposed between the address electrodes and the phosphor layer. The method of claim 1, And at least a side surface of the front partition wall is covered by a protective film. The method of claim 1, And the front partition wall and the rear partition wall are integrally formed.