KR20060001549A - Plasma display panel - Google Patents

Abstract

The present invention relates to a plasma display panel having an improved electrode structure, comprising: a pair of substrates facing each other; An address electrode formed at any one of the substrates; A partition wall disposed in a space between the substrates to form discharge cells according to the colors of blue, green, and red; A phosphor layer formed in the discharge cell; And a pair of display electrodes facing each other in the discharge cells to form a discharge gap, wherein the display electrodes are formed by a combination of two or more line portions, and positioned along at least one color. The line parts of the discharge cells are connected to each other by a pair of connection parts positioned adjacent to the partition wall.

Plasma, metal electrode, panel, white balance, brightness, color temperature

Description

Plasma Display Panel {PLASMA DISPLAY PANEL}

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

2 is a layout view illustrating an electrode structure according to an exemplary embodiment of the present invention together with a partition wall.

3 is a layout view illustrating an electrode structure according to another exemplary embodiment of the present invention together with a partition wall.

4 is a diagram illustrating a distribution of luminance of one discharge cell in a plasma display panel.

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 having improved luminance by improving an electrode structure.

Plasma display panels (hereinafter referred to as 'panels') are ultraviolet rays generated during a plasma discharge process by disposing a discharge cell between a pair of glass substrates and a pair of display electrodes formed corresponding to the discharge cells. Is a display that displays an image by excitation.

In this case, in order not to block the light emitted from the substrate, the display electrode is generally formed of a transparent electrode. However, since the transparent electrode itself has high resistance, in order to compensate for its conductivity, the display electrode is formed by combining the metal electrode with the transparent electrode.

In this case, the transparent electrode is made of a material such as indium tin oxide (ITO) or SnO _2, and the metal electrode is a thin film made of three layers of Ag, Cr / Cu / Cr, or a thin film made of a two-layer structure of Al / Cr. do.

Such a conventional electrode structure forms a metal electrode on a glass substrate by a photo etching method, a liftoff method, and a transparent electrode by a photo etching method and a liftoff process in the following process. Form by law.

Therefore, there is a disadvantage that the work process is very complicated, thereby increasing the manufacturing cost of the panel. In addition, since the transparent electrode itself is expensive, this also increases the manufacturing cost.

Therefore, efforts are being made to form the display electrode only with the metal electrode without using the transparent electrode, and one of the related arts is the "plasma display panel" disclosed in US Pat. No. 6,522,072.

According to this, there is an advantage that the manufacturing cost can be lowered as compared with the electrode structure described above. However, the display electrode formed of only the metal electrode has a problem of lowering the aperture ratio of the panel and thus decreasing luminance.

As an alternative to solve this problem, it is possible to consider a method of increasing the distance between the two metal electrodes positioned with the discharge gap in between, but this is because the problem of increasing the discharge voltage and the unstable discharge becomes low This is required.

On the other hand, since the discharge occurring inside the discharge cell is induced by the dielectric layer, the phosphor layer, and the discharge gas existing between the address electrode and the display electrode, the material properties and the shape properties of these structures have a great influence on the discharge. Since the dielectric layer is formed to have a uniform thickness throughout the substrate, it can be said that there is no characteristic difference for each of the red, green, and blue discharge cells.

However, a blue phosphor of a material such as BaMgAl ₁₀ O ₁₇ : Eu (barium magnesium aluminate with emission center), Zn ₂ SiO ₄ : Mn (zinc silicate with Mn emission center), BaAl ₁₂ O ₁₉ : A phosphor layer composed of a green phosphor such as YBO ₃ : Tb, a red phosphor such as Y _0.35 Gd _0.35 BO ₃ (yttrium gadolinium borate with Eu as the emission center), Y ₂ O ₃ : EU, and Gd ₂ O ₃ : Eu Since the dielectric constant is different for each color and a substantial thickness difference occurs for each color when the panel is manufactured, a capacitance difference occurs due to a material characteristic and a thickness difference of the phosphor layer, and thus the emission luminance is different for each of the red, green, and blue discharge cells. This happens.

In particular, when the luminance of the blue discharge cell becomes relatively low, the color temperature (or white balance) becomes low, which is undesirable because the optic nerve of the human recognizes that the brightness of the panel is relatively dark. Therefore, the white balance is adjusted through the circuit gamma correction. In this case, the white balance is adjusted based on the blue luminance because it is relatively low. Accordingly, luminance loss occurs through gamma adjustment by a magnitude corresponding to the luminance difference between blue and red (or green).

On the other hand, Figure 4 is a view showing the distribution of luminance for one discharge cell in the panel, it can be seen that there are the following characteristics.

In the drawing, only the display electrode 101 and the partition wall 201 are selectively shown, and a graph showing luminance distribution according to the electrode in the row direction is shown based on the drawing by extending the display electrode. The luminance distribution is shown. According to this, the closer to the partition wall, the higher the brightness, which is due to the large amount of phosphor coated on the wall of the partition wall. . In addition, the closer the discharge gap W is, the higher the luminance is, because the intensity of the discharge and the shielding of the visible light by the electrode do not occur.

The present invention has been devised to solve the above-described problems, and it is an object of the present invention to improve the aperture ratio of a panel using only metal electrodes and to adjust the color temperature while reducing the loss of luminance.

In order to achieve the above object, the plasma display panel provided by the present invention,

A pair of substrates opposed to each other;

An address electrode formed at any one of the substrates;

A partition wall disposed in a space between the substrates to form discharge cells according to the colors of blue, green, and red;

A phosphor layer formed in the discharge cell; And,

And a pair of display electrodes facing each other in the discharge cell to form a discharge gap.

The display electrode,

Formed by a combination of two or more line portions, the line portions for each discharge cell positioned along at least one color are connected to each other by a pair of connecting portions positioned adjacent to the partition wall.

In this case, the line parts positioned along the blue discharge cells are connected to each other by a pair of connection parts, and the line parts located along the green and red discharge cells are connected to each other by one connection part. desirable.

On the other hand, the display electrode,

A first line part facing each other with the discharge cells interposed therebetween; and

A second line part forming a discharge gap inside the discharge cell;

And a third line part positioned between the first line part and the second line part.

In this case, the line parts are formed to extend in a direction crossing the address electrode while being spaced apart from each other.

Further, the discharge gap is preferably composed of a first gap and a second gap of different lengths, and the second gap larger than the first gap is formed at the point where the second line portion and the connection portion meet.

In the present invention, the line portions and the connecting portion are formed in an elongated bar shape to improve the opening ratio of the panel. In this case, the line parts and the connection part are preferably formed of a metal electrode.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

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

Referring to the drawings, the plasma display panel (hereinafter, referred to as 'panel') according to the present embodiment has a pair of substrates 2 and 4 disposed to face each other at random intervals, and the partition wall 12 is disposed between the two substrates. The color-specific discharge cells 8R, 8G, and 8B formed by the are provided. At this time, the address electrodes 8 are preferably located side by side at regular intervals with a neighboring address electrode along the center of the width direction (X-axis direction of the drawing) of the discharge cells (8R, 8G, 8B).

The address electrodes 8 are formed on the inner surface of the substrate 2 along the X-axis direction of the drawing, and the dielectric layer 10 is formed on the entire inner surface of the substrate 2 while covering the address electrodes 8.

A partition 12 is formed on the dielectric layer 10, and red, green, and blue phosphor layers 14R, 14G, and 14B are formed on the wall surfaces of the partition 12 and the dielectric layer 10. At this time, the partition wall 12 is disposed between each address electrode 8.

In the drawing, the partition 12 has a matrix-shaped discharge cell 8R, 8G, and 8B formed by a horizontal partition 12a formed in the Y-axis direction and a vertical partition 12b formed along the X-axis direction. Although illustrated as a structure arranged in, the present invention is not intended to be limited thereto. For example, the partition 12 may be a stripe structure parallel to each other along the Y-axis direction of the drawing, or a delta structure forming a triangular array.

The pair of display electrodes including the scan electrode 16 and the sustain electrode 18 is formed on the substrate 4 facing the substrate 2 along the direction crossing the address electrode 8 (the Y-axis direction in the drawing). A 20 is formed, and the dielectric layer 22 and the MgO protective film 24 are positioned over the entire inner surface of the substrate 4 while covering the display electrodes 20.

In the present embodiment, the display electrode 20 is formed of a combination of a plurality of line parts formed of a conductive material of metal. The electrode structure according to the present embodiment will be described in detail with reference to FIGS. 2 and 3 below.

On the other hand, the address electrodes 8 and the display electrodes 20 cross each other by the combination of the substrates 2 and 4 to form discharge cells 8R, 8G, and 8B, and the discharge cells are vacuumed by plasma discharge. It is filled with discharge gases (mainly Ne-Xe mixed gases) which induce the emission of ultraviolet rays.

Based on such a configuration, the panel of this embodiment generates reset discharge between the display electrodes 20 to reset the state of charge inside the discharge cells. Then, an address voltage is applied between the address electrode 8 and the scan electrode 16 to charge the wall charges. Accordingly, the discharge cell in which the image is represented is selected. After the discharge cells are selected in this manner, images are displayed by applying alternating pulses to the display electrodes.

Hereinafter, the electrode structure according to the present embodiment will be described, but the display electrode 20 of the present embodiment is formed by a combination of a plurality of line portions made of metal electrodes without using a transparent electrode.

FIG. 2 is a diagram illustrating an electrode structure according to an exemplary embodiment. For example, the luminance of a blue discharge cell is lower than that of a discharge cell of a different color, and thus an example in which white balance is adjusted through luminance compensation of the blue discharge cell is shown. For example, but the present invention is not limited thereto.

Referring to FIG. 2, the display electrode 20 according to the present exemplary embodiment includes a pair of first line portions 161 and 181 facing the discharge cells 8R, 8G, and 8B and positioned in parallel with each other, and the first line. And second line portions 162 and 182 which are positioned between the portions 161 and 181 and face each other inside the discharge cell to form a discharge gap G.

The second line parts 162 and 182 face each other inside the discharge cell in a state spaced apart from the first line part by a predetermined distance to form a discharge gap G, and discharge according to a voltage pulse applied to each electrode. Form an initial counter discharge.

The initial counter discharge is induced between surface discharges while being diffused between the first line portions 161 and 181. At this time, when the distance between the first line portions 161 and 181 and the second line portions 162 and 182 becomes too wide, the discharge does not diffuse, and thus the first line portions 161 and 181 and the second line portions 162 and Third line portions 163 and 183 may be further formed between the 182 to induce discharge diffusion (see FIG. 3).

The line parts 161 to 163 and 181 to 183 are formed to extend in a direction crossing the address electrode 8 while being spaced apart from each other.

Accordingly, the counter discharges formed between the second line portions 162 and 182 cross-link the third line portions 163 and 183 to the first line portions 161 and 181 while inducing surface discharge.

Thus, substantially the scan electrode 16 and the holding The electrode 18 is formed by the combination of the line portions 161 to 163 and 181 to 183, wherein the line portions 161 to 163 and 181 to 183 are thin and long bars. It is preferable that it is formed in a shape.

Therefore, each of the electrodes 16 and 18 forms an empty space, and thus, the electrodes do not shield visible light from each discharge cell, thereby improving the luminance of the panel.

Hereinafter, an example of adjusting the white balance by compensating for the luminance step of the blue discharge cell will be described.

As described above with reference to FIG. 4, it has been described that the luminance is high at the partition wall surface in one discharge cell.

In view of this point, in the present embodiment, a pair of connecting portions 164a and 164b for interconnecting the line portions 161 to 163 and 181 to 183 for the blue discharge cell 8B is selectively provided as a vertical bulkhead ( 12b) formed adjacent to the wall. Experimentally, it is preferable that the connecting portions 164a and 164b are spaced apart by about 10 to 20 μm from the phosphor layer 14B formed on the wall surface of the vertical partition wall 12b.

The connecting portions 164a and 164b provide passages through which charges generated by plasma discharge move. Thus, by arranging the connecting portions 164a and 164b adjacent to the wall of the vertical bulkhead 12b, the charge distribution around the wall of the vertical bulkhead 12b is adjusted. You can increase it probability. As a result, the probability of excitation of the phosphor here increases, and the luminance of the blue discharge cell 8B is increased.

Meanwhile, the line portions 161 to 163 and 181 to 183 positioned along the red and green discharge cells 8R and 8G have a structure in which one connection portion 164 and 184 selectively connects the line portions to each other. .

As a result, the luminance difference between the blue and the red (or green) is reduced, so that the white balance can be adjusted while relatively reducing the luminance of the red or green discharge cells, thereby improving the efficiency of the panel.

In the present embodiment, the discharge gap G in which the counter discharge at the initial stage of discharge is formed is preferably formed by a combination of the first gap G1 and the second gap G2. In this case, the second gap G2 forms a discharge gap longer than the first gap G1.

By forming the counter discharges with different lengths, the counter discharges generated through the first gap G1 can be easily induced to the surface discharges between the first line portions 161 and 181 by crosslinking the second gap G2. To help.

Meanwhile, in FIGS. 2 and 3, the recess 165 having the second gap G2 recessed inward at a point P where the connecting portions 164 and 184 and the second line portions 162 and 182 meet with each other is formed. The case is formed through the 185, the second gap G2 is formed by connecting the connecting portions 164 and 184 as described above. Thus, the diffusion of discharge is further increased by the combination of the second gap G2 and the connecting portions 164 and 184. It can be easily formed.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

According to the present invention, it is possible to solve the above-mentioned problems and to reduce the loss of luminance relatively in adjusting the white balance.

In addition, since the electrodes are formed in a partially formed empty space, there is an advantage in that the opening ratio of the panel is improved compared to the prior art to increase the light emission luminance.

In addition, since each line portion is formed in a structure independent from each other, even if a disconnection occurs in any one electrode, the other line portion compensates for the disconnected electrode, thereby causing a defect due to the electrode disconnection of the panel, while the disconnected line portion is separated from other lines. By additional compensation, there is an advantage that the luminous efficiency and luminance can be maintained as it is.

Claims (9)

A pair of substrates opposed to each other; An address electrode formed at any one of the substrates; A partition wall disposed in a space between the substrates to form discharge cells according to the colors of blue, green, and red; A phosphor layer formed in the discharge cell; And, And a pair of display electrodes facing each other in the discharge cell to form a discharge gap. The display electrode, A plasma display panel formed by a combination of two or more line units, wherein the line units for each discharge cell positioned along at least one color are connected to each other by a pair of connection units adjacent to the partition wall. The method of claim 1, And the line parts positioned along the blue discharge cells are connected to each other by a pair of connection parts. The method of claim 2, And the line parts positioned along the green and red discharge cells are connected to each other by one connection part. The method according to any one of claims 1 to 3, The display electrode, A first line part facing each other with the discharge cells interposed therebetween; and A second line part forming a discharge gap inside the discharge cell; And a third line portion positioned between the first line portion and the second line portion. The method of claim 4, wherein And the line portions extending in a direction crossing the address electrode while being spaced apart from each other. The method of claim 4, wherein And a discharge gap having a first gap and a second gap of different lengths. The method of claim 6, And a second gap larger than the first gap at a point where the second line portion and the connection portion meet. The method of claim 4, wherein And the line parts and the connection part have a thin long bar shape. The method of claim 4, wherein And the line parts and the connection part are formed of metal electrodes.

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