KR20050112572A - Plasma display panel - Google Patents

Abstract

The present invention discloses a plasma display panel. According to the invention, the transparent upper substrate; A lower substrate disposed to face the upper substrate; A first partition wall disposed between the upper substrate and the lower substrate, defining discharge cells together with the upper substrate and the lower substrate, and formed of a dielectric; Upper discharge electrodes disposed in the first partition wall to surround the discharge cells; Lower discharge electrodes disposed in the first partition wall to surround the discharge cells and spaced apart from the upper discharge electrodes; A black layer disposed on the bottom surface of the first partition wall; A phosphor layer disposed in the discharge cell; And a discharge gas filled in the discharge cell.

Description

Plasma display panel {Plasma display panel}

The present invention relates to a plasma display panel that implements an image using gas discharge.

The device employing the plasma display panel has a large screen, high quality, ultra-thin, light weight, and excellent characteristics of wide viewing angle, and is simpler to manufacture than other flat panel display devices and is easy to be enlarged. It has been in the spotlight as a 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 may be classified into a counter discharge type and a surface discharge type according to a discharge structure. In general, an AC plasma display panel having an AC three-electrode surface discharge structure is generally employed.

1 shows a conventional AC three-electrode surface discharge plasma display panel.

The illustrated plasma display panel 10 is provided with an upper substrate 11 and a lower substrate 21 opposite thereto.

On the lower surface of the upper substrate 11, a pair of sustain electrodes 12 formed of a pair of common electrodes 13 and scan electrodes 14 forming a discharge gap with the common electrode 13 are formed. 13 and scan electrodes 14 are embedded by upper dielectric layer 15. A protective layer 16 is formed on the lower surface of the upper dielectric layer 15.

In addition, address electrodes 22 are formed on the upper surface of the lower substrate 21 to cross the common electrodes 13 and the scan electrodes 14, and the address electrodes 22 are formed on the lower dielectric layer 23. It is buried by. Discharge spaces 25 are partitioned by partition walls 24 formed on the upper surface of the lower dielectric layer 23 at predetermined intervals. Phosphor layers 26 are formed in the discharge spaces 25, respectively, and discharge gases are filled in the discharge spaces 25.

In the plasma display panel 10 configured as described above, ultraviolet rays are emitted from the plasma generated by the discharge in the discharge space 25. Such ultraviolet rays excite the phosphor layer 26, and visible light is emitted from the phosphor layer 26 thus excited, thereby displaying an image.

However, due to the structure in which the electrodes 13 and 14, the upper dielectric layer 15, and the protective layer 16 are sequentially formed from the lower side of the upper substrate 11, visible light emitted from the phosphor layer 26 is generated. By absorbing this about 40%, there was a limit to increasing the luminous efficiency. In addition, when the same image is displayed for a long time, there is a problem that the charged particles of the discharge gas are ion sputtered on the phosphor layer 26 by an electric field, causing permanent afterimages and shortening the lifespan.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a plasma display panel capable of improving luminance and luminous efficiency, and improving bright room contrast.

Plasma display panel according to the present invention for achieving the above object,

A transparent upper substrate;

A lower substrate disposed to face the upper substrate;

A first partition wall disposed between the upper substrate and the lower substrate, defining discharge cells together with the upper substrate and the lower substrate, and formed of a dielectric;

Upper discharge electrodes disposed in the first partition wall to surround the discharge cell;

Lower discharge electrodes disposed in the first partition wall to surround the discharge cells and spaced apart from the upper discharge electrodes;

A black layer disposed on a lower surface of the first partition wall;

A phosphor layer disposed in the discharge cell;

And a discharge gas filled in the discharge cell.

Here, the black layer is preferably formed of a black dielectric.

Here, the side surfaces of the first partition and the black layer are preferably covered with a protective film.

The upper discharge electrode may extend in one direction, and the lower discharge electrode may extend in a direction crossing the direction in which the upper discharge electrode extends.

Here, the upper discharge electrode and the lower discharge electrode respectively extend in parallel in one direction, and are disposed in the discharge cells, and further include address electrodes extending along a direction crossing the upper discharge electrode and the lower discharge electrode. Is preferred.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 and 3 illustrate a plasma display panel according to an embodiment of the present invention.

2 and 3, the plasma display panel 100 includes an upper substrate 111 and a lower substrate 121 disposed to face the upper substrate 111.

The upper substrate 111 and the lower substrate 121 are formed of a light transmissive material such as glass. In particular, since the image is displayed from the upper substrate 111, the upper substrate 111 has excellent light transmittance. desirable. In addition, between the upper substrate 111 and the lower substrate 121, a first partition 112 and a second partition 124 are formed in a predetermined pattern and disposed up and down.

As shown, the first and second partitions 112 and 124 are each formed as a closed partition of a matrix having a rectangular cross section. In addition, a lower surface of the first partition wall 112 corresponds to an upper surface of the second partition wall 124 so that a space defined by the first partition wall 112 and a space defined by the second partition wall 124 correspond to each other. It is done.

However, the present invention is not limited thereto, and the first and second partitions may be formed of closed partitions such as waffles or deltas, or may be polygonal partitions such as triangles or pentagons, or closed partitions of circular or oval shapes, respectively. Can be formed. In addition, the first partition may be formed as a closed partition, while the second partition may be formed in various combinations, such as a stripe-shaped open partition.

The first partition 112 and the second partition 124 together with the upper and lower substrates 111 and 121, a red subpixel, a green subpixel, and a blue subcomponent, which constitute a unit pixel for color implementation. Among the subpixels, each of the sub-pixels is divided into discharge cells 115 corresponding to one sub-pixel, and erroneous discharge due to cross talk or the like is prevented between the divided discharge cells 115. The first and second partitions 112 and 124 may be formed separately as illustrated, or the first and second partitions may be integrally formed of the same material.

Meanwhile, address electrodes 122 are formed on an upper surface of the lower substrate 121 facing the upper substrate 111, and the address electrodes 122 are covered by the dielectric layer 123. The address electrodes 122 are formed to correspond to the discharge cells 115 so as to select the discharge cells 115 to start discharge. The address electrodes 122 are illustrated as being formed in a stripe shape, but are not necessarily limited thereto.

The dielectric layer 123 prevents cations or electrons from colliding with the address electrodes 122 to damage the address electrodes 122 during discharge, and induce charge. The dielectric layer 123 may be formed of a dielectric such as PbO, B ₂ O ₃ , SiO ₂ , Al ₂ O _3, or the like.

In the discharge cell 115, a phosphor layer 125 that is excited by ultraviolet rays generated during sustain discharge and emits visible light is disposed. As illustrated, the phosphor layer 125 is formed over a space defined by the second partition wall 124, that is, the top surface of the dielectric layer 123 and the side surfaces of the second partition wall 124.

The phosphor layer 125 includes phosphors that are excited by ultraviolet rays generated during discharge and emit red, green, and blue visible rays, respectively. For example, the red phosphor layer formed in the discharge cell corresponding to the red subpixel includes phosphors such as Y (V, P) O ₄ : Eu, and the green phosphor layer formed in the discharge cell corresponding to the green subpixel is Zn. ₂ SiO ₄ : Mn, YBO ₃ : Tb and the like, and the blue phosphor layer formed in the discharge cell corresponding to the blue subpixel includes a phosphor such as BAM: Eu and the like.

Since the phosphor layer 125 is formed in a space defined by the second partition 124, the phosphor layer 125 is significantly spaced apart from the main region on the side of the first partition 112 where a sustain discharge occurs. Accordingly, the phosphor layer 125 may be prevented from being ion-sputtered by the charged particles, thereby improving lifespan characteristics, and even after the same image is implemented for a long time, the phenomenon of permanent afterimage generation may be significantly reduced.

The discharge gas is filled in the discharge cell 115 in which the phosphor layer 125 is disposed. As the discharge gas, a conventional mixed gas including Xe for generating ultraviolet rays and Ne, which functions as a buffer, are mixed. May be employed.

Meanwhile, in the first partition 112 that partitions the discharge cell 115 together with the second partition 124 as described above, discharge occurs in the discharge cells 115, as illustrated in FIGS. 2 and 3. As described above, the upper discharge electrodes 113 and the lower discharge electrodes 114 are formed to be disposed up and down, respectively. The upper discharge electrode 113 is disposed above the upper substrate 111 side, and the lower discharge electrode 114 is disposed below the upper discharge electrode 113 in the vertical direction. . The upper discharge electrode 113 and the lower discharge electrode 114 may be formed of a conductive metal such as aluminum, copper, silver, or the like. Accordingly, since the resistance is lower than that of the electrode formed of ITO, the discharge response speed may be faster than that of the conventional panel using the ITO electrode.

The first partition wall 112 filling the upper discharge electrodes 113 and the lower discharge electrodes 114 is formed of a dielectric. Accordingly, it is possible to prevent direct energization between the upper discharge electrode 113 and the lower discharge electrode 114, and the charged particles directly collide with the upper discharge electrode 113 and the lower discharge electrode 114 during discharge, so that they Damage can be prevented and it can be easy to induce charged particles to accumulate wall charges. PbO, B ₂ O ₃ , SiO ₂ , Al ₂ O _3, or the like may be used as the dielectric for forming the first partition wall 112.

In addition, an MgO layer 116 having a predetermined thickness may be further formed on a side surface of the first partition wall 112. As the MgO film 116 is formed as described above, the collision of the charged particles generated during discharge directly with the first partition wall 112 may be blocked by the MgO film 116, and thus, by ion sputtering of the charged particles. Damage to the first partition wall 112 may be prevented. In addition, as the charged particles directly collide with the MgO film 116 as described above, secondary electrons that contribute to the discharge may be emitted from the MgO film 116, thereby enabling low voltage driving and emitting efficiency. This can be high.

The upper discharge electrodes 113 and the lower discharge electrodes 114 disposed in the first partition wall 112 will be described in more detail with reference to FIG. 4.

The upper discharge electrodes 113 disposed on the upper side of the first partition wall 112 extend along discharge cells 115 arranged in a direction orthogonal to the direction in which the address electrode 122 is formed. Here, one upper discharge electrode 113 is formed in a ladder shape consisting of long side portions spaced apart from each other and short side portions connecting therebetween, and the upper discharge electrode 113 is formed in a direction in which the address electrode 122 is formed. Each of the discharge cells 115 arranged in the orthogonal direction is arranged to surround four side surfaces.

The upper discharge electrodes 113 formed as described above are disposed to be spaced apart at predetermined intervals along the formation direction of the address electrode 122. In the upper discharge electrodes 113, adjacent long side parts spaced apart from each other are disposed in the first partition wall 112 disposed therebetween. However, the present invention is not limited thereto, and the first partition wall may be formed as a double partition wall, and a long side part may be disposed to be spaced apart from each other.

The lower discharge electrodes 114 disposed in the first partition 112 spaced apart from the upper discharge electrodes 113 at predetermined intervals may be formed in parallel with the upper discharge electrode 113 described above. That is, the lower discharge electrodes 114 extend in a ladder shape along discharge cells 115 arranged in a direction orthogonal to the direction in which the address electrodes 122 are formed, and one lower discharge electrode 114 has an address. Each of the discharge cells 115 arranged in a direction orthogonal to the direction in which the electrode 122 is formed is arranged to surround four side surfaces.

In addition, the lower discharge electrodes 114 formed as described above are disposed to be spaced apart at predetermined intervals along the formation direction of the address electrode 122. In the lower discharge electrodes 114, long sides spaced apart from each other are adjacent to each other. The parts are arranged in the first partition 112 located between them. As described above, the upper discharge electrode 113 and the lower discharge electrode 114 which surround four side surfaces of each of the discharge cells 115 and are spaced apart by the discharge gap are disposed, so that the discharge area where the discharge occurs is the circumference of the discharge cell 115. Direction can be enlarged, and the luminous efficiency can be improved.

The upper discharge electrode 113 and the lower discharge electrode 114 disposed in each of the discharge cells 115 are shown to be symmetrical up and down, but may be asymmetric. In addition, the upper discharge electrode and the lower discharge electrode is formed in a closed shape such as a ladder shape so as to surround all four sides of each discharge cell, but is not necessarily limited thereto.

One of the upper discharge electrode 113 and the lower discharge electrode 114 having the structure described above corresponds to a common electrode and the other corresponds to a scan electrode, and thus, between the upper discharge electrode 113 and the lower discharge electrode 114. The charged particles move in the vertical direction by the sustain discharge voltage applied alternately to cause sustain discharge.

Here, the upper discharge electrode 113 serves as a common electrode, and the lower discharge electrode 114 serves as a scan electrode, or conversely, the upper discharge electrode 113 serves as a scan electrode and the lower discharge electrode 114 shares in common. Can act as an electrode respectively. However, when the lower discharge electrode 114 acts as a scan electrode, an address voltage applied between the lower discharge electrode 114 and the address electrode 122 may be lowered to more smoothly perform address discharge therebetween. It would be more preferable.

The address electrode 122 causing the address discharge as described above accumulates charges on the upper discharge electrode 113 side and the lower discharge electrode 114 side after the address discharge is completed, thereby causing the upper discharge electrode 113 to be discharged. ) And the lower discharge electrode 114 can make the sustain discharge easier. Accordingly, the voltage at which the sustain discharge is started can be lowered. Meanwhile, the address electrode may be omitted. In this case, the discharge cells may be selected and discharged only when the upper discharge electrode and the lower discharge electrode are disposed to cross each other.

On the other hand, a black layer 130 is disposed on the lower surface of the first partition wall 112 to absorb external light and reduce reflection brightness. In more detail, the black layer 130 is disposed between the first partition wall 112 and the second partition wall 124 and is formed in the same pattern as the first partition wall 112. The cross section of 130 has the same shape as the cross section of the first partition wall 112. In addition, the black layer 130 is disposed such that an upper surface thereof is spaced apart from a lower surface of the lower discharge electrode 114 at a predetermined interval.

It is preferable that the black layer 130 is formed of a dielectric like the first partition wall 112 because the black layer 130 may increase the effect of inducing charged particles together with the first partition wall 112 formed of the dielectric material to accumulate wall charges. to be. The dielectric layer forming the black layer 130 may be formed of CoO, Fe ₂ O _{3, or the} like, which is black in at least one selected from PbO, B ₂ O ₃ , SiO ₂ , and Al ₂ O _3. At least one selected may be mixed. Here, it may be preferable that the passivation layer 116 covering the side surface of the first partition wall 112 is extended and covered on the side surface of the black layer 130 formed of the black dielectric material as described above.

Meanwhile, as illustrated in FIG. 5, the black layer 130 may be disposed so that the top surface of the black layer 130 is in contact with the bottom surface of the lower discharge electrode 114. In this case, the black layer 130 may be disposed. ) May be disposed relatively closer to the upper substrate 111 side than in the above-described example, thereby increasing the effect of reducing the reflection brightness due to external light and simplifying the manufacturing process. In addition, the black layer 130 does not need to be formed too thick because the role of contributing to discharge is smaller than that of the first partition wall 112. Therefore, it is preferable that the black layer 130 is formed to be approximately 40 μm or less.

As the black layer 130 is disposed between the first partition wall 112 and the second partition wall 124, external light incident from the outside of the upper substrate 112 is absorbed and the reflection luminance is reduced. Therefore, the clear room contrast of the panel 100 can be improved.

Referring to the operation of the plasma display panel 100 configured as described above is as follows.

First, an address voltage is applied between an address electrode 122 and a lower discharge electrode 114 acting as a scan electrode, so that an address discharge occurs, and as a result of the address discharge, a discharge cell 115 to generate a sustain discharge is selected. Lose. After the address discharge is executed, if the sustain discharge voltage is alternately applied between the upper discharge electrode 113 and the lower discharge electrode 114 disposed in the selected discharge cell 115, the upper discharge electrode 113 and the lower discharge are applied. A sustain discharge occurs between the electrodes 114.

The sustain discharge is concentrated on the upper side of the discharge cell 115, and occurs in the vertical direction on all sides defining the discharge cell 115. As described above, the sustain discharge generated from all sides of the discharge cell 115 gradually diffuses to the center side of the discharge cell 115. Therefore, the discharge area becomes relatively wider than that of the conventional panel shown in FIG. 1, and the volume of the area where the sustain discharge occurs is increased, so that the space charge in the discharge cell 115, which has not been used conventionally, also contributes to light emission. do. Accordingly, the amount of plasma to be formed during discharge can be increased to enable low voltage driving. Ultraviolet rays are emitted while the energy level to the discharged gas excited by the sustain discharge is lowered. The ultraviolet rays excite the phosphor layer 125 formed in the discharge cell 115, and visible light is emitted from the excited phosphor layer 125 to realize an image. In this case, since the black layer 130 is disposed on the bottom surface of the first partition wall 112, external light is absorbed and the reflection luminance may be reduced, thereby obtaining high clear room contrast.

As described above, the plasma display panel according to the present invention has the following effects.

First, since the electrodes and the dielectric layer do not exist in a region where visible light emitted from the discharge cell is transmitted in the upper substrate, the transmittance can be improved by increasing the aperture ratio, and discharge occurs on all sides of the discharge cell. The discharge area can be greatly enlarged, so that low voltage driving can be enabled.

Second, as the phosphor layer disposed in the lower region of the discharge cell is spaced apart from the main region where sustain discharge occurs, the phosphor can be prevented from ion sputtering by the charged particles, thereby ensuring sufficient lifespan.

Third, as the black layer is disposed on the bottom surface of the first partition wall, external light may be absorbed and the reflection brightness may be reduced, thereby improving the clear room contrast of the panel.

Although the present invention has been described with reference to one embodiment shown in the accompanying 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. Could be. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

1 is a partially separated perspective view of a plasma display panel according to a conventional example.

2 is a partially separated perspective view of 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;

FIG. 4 is a partial perspective view illustrating the electrodes in FIG. 2; FIG.

FIG. 5 is a sectional view of a light absorbing layer according to another example of FIG. 3.

<Brief description of the major symbols in the drawings>

111. Upper substrate 112. First bulkhead

113. Top discharge electrode 114. Bottom discharge electrode

115. Discharge cell 121. Lower substrate

122. Address electrode 123 Dielectric layer

124. Second bulkhead 130. Black layer

Claims (11)

A transparent upper substrate; A lower substrate disposed to face the upper substrate; A first partition wall disposed between the upper substrate and the lower substrate, defining discharge cells together with the upper substrate and the lower substrate, and formed of a dielectric; Upper discharge electrodes disposed in the first partition wall to surround the discharge cell; Lower discharge electrodes disposed in the first partition wall to surround the discharge cells and spaced apart from the upper discharge electrodes; A black layer disposed on a lower surface of the first partition wall; A phosphor layer disposed in the discharge cell; And a discharge gas filled in the discharge cell. The method of claim 1, And the black layer is formed of a black dielectric. The method of claim 2, The black dielectric is plasma display panel, characterized in that at least one selected from CoO, Fe ₂ O ₃ and the like is mixed with at least one selected from PbO, B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ and the like. The method of claim 1, And an upper surface of the black layer is spaced apart from a lower surface of the lower discharge electrode at predetermined intervals. The method of claim 1, And an upper surface of the black layer is in contact with a lower surface of the lower discharge electrode. The method of claim 1, The thickness of the black layer is a plasma display panel, characterized in that 40㎛ or less. The method of claim 1, And a passivation layer on the sidewalls of the first partition and the black layer. The method of claim 1, And the upper discharge electrode extends in one direction, and the lower discharge electrode extends in a direction crossing the direction in which the upper discharge electrode extends. The method of claim 1, The upper discharge electrode and the lower discharge electrode respectively extend in parallel in one direction, and are disposed in the discharge cells, and further include address electrodes extending along a direction crossing the upper discharge electrode and the lower discharge electrode. Characterized in that the plasma display panel. The method of claim 9, And the address electrodes are covered by a dielectric layer further provided between the lower substrate and the phosphor layer. The method of claim 1, And a second partition wall defining a discharge cell together with the first partition wall between the lower substrate and the black layer, and a phosphor layer disposed in a space defined by the second partition wall.