KR20080016043A - Plasma display panel - Google Patents

Abstract

A plasma display panel is provided to increase luminance by coloring a rear substrate with a color for reflecting visible light. A front substrate(16) and a rear substrate(10) are disposed to be opposite to each other. The front substrate is colored with a first color. An address electrode(11) is extended in a first direction on the rear substrate. A rear dielectric layer(12) is formed to cover the address electrode on the rear substrate. A barrier rib(13) is arranged between the front and rear substrates to define discharge cells. A phosphor layer(14) is formed on the inside of the discharge cells. A display electrode(17) is formed in a second direction crossing a first direction on the front substrate. A front dielectric layer(18) is formed on the front substrate in order to cover the display electrode. The front dielectric layer includes a first layer(18a) colored with a second color and a second layer(18b) colored with a third color. The subtractive mixture relationship is formed in the first, second, and third colors.

Description

Plasma Display Panel {Plasma Display Panel}

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

FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1.

3 is a plan view illustrating an image display area of a plasma display panel according to an exemplary embodiment of the present invention.

4 is a view schematically showing the relationship between colors that appear when three primary colors of a color material overlap.

<Explanation of symbols for the main parts of the drawings>

10: back substrate 11: address electrode

12: back dielectric layer 13: bulkhead

13a: vertical partition member 13b: horizontal partition member

14: phosphor layer 15: discharge cell

16: front substrate 17: display electrode

17a: scan electrode 17b: sustain electrode

18: front dielectric layer 18a: first layer

18b: second layer 19: protective layer

20: bus electrode 30: image display area

30a: first region 30b: second region

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 adopting subtractive mixing, which has a low reflection brightness and improved black ratio and clear room contrast.

In general, a plasma display panel uses ultraviolet (UV) rays emitted from a plasma obtained through gas discharge. This ultraviolet light excites the phosphor layer, and the excited phosphor layer generates visible light. The visible light has red (R), green (G), and blue (B) depending on the type of the phosphor layer, and the combination of them is realized.

As an example, an AC plasma display panel includes an address electrode on a rear substrate, and a dielectric layer covers the address electrode. In addition, a partition wall is formed in a stripe shape on the dielectric layer, and a phosphor layer is formed inside the partition wall.

The front substrate is provided spaced apart from the rear substrate by a predetermined distance, and the display electrodes, the dielectric layer, and the protective layer are sequentially formed on the front substrate. The display electrode is formed in a direction crossing the address electrode.

Discharge cells are formed at the intersections of the address electrodes on the rear substrate and the display electrodes on the front substrate, which are divided by partition walls. More than millions of unit discharge cells are arranged in a matrix or stripe form inside the plasma display panel.

In the plasma display panel, the principle of causing discharge in the discharge cells will be described in more detail. In order to cause the discharge between the sustain electrode and the scan electrode, a potential difference of a specific voltage or more is required therebetween, and the discharge voltage is started. It is called a firing voltage (Vf).

Once the scan voltage and the address voltage are applied to the scan electrode and the address electrode, the discharge is initiated between them to form a plasma in the discharge cell, and the electrons and ions constituting the plasma move toward the electrodes having opposite polarities. .

On the other hand, the plasma display panel is coated with a dielectric layer, so that most of the space charges transferred are accumulated in the dielectric layer having the opposite polarity, so that the net potential between the scan electrode and the address electrode is originally applied to the address voltage Va. It becomes lower, the discharge is weakened and the address discharge is extinguished.

A relatively small amount of electrons is accumulated on the sustain electrode, and a relatively large amount of ions are accumulated on the scan electrode. The charges accumulated in the dielectric layers covering the sustain electrodes and the scan electrodes form wall charges (Qw), and wall voltages (Vw) are formed between the sustain electrodes and the scan electrodes by these wall charges.

Subsequently, when the discharge sustain voltage Vs is applied to the sustain electrode and the scan electrode, the sum of the magnitudes of the discharge sustain voltage Vs and the wall voltage Vw (Vs + Vw) is the discharge start voltage Vf. If higher, sustain discharge occurs in the discharge cell. Ultraviolet (UV) generated at this time excites the phosphor layer, and the phosphor layer emits visible light. Visible light is transmitted to the outside of the plasma display panel through the front substrate.

On the other hand, when there is no address discharge between the scan electrode and the address electrode (that is, when the address voltage Va is not applied), wall charges do not accumulate between the sustain electrode and the scan electrode, and consequently, the sustain electrode and the scan electrode. There is no wall voltage in between.

At this time, only the discharge sustain voltage Vs applied to the sustain electrode and the scan electrode is formed in the discharge cell. Since the discharge sustain voltage is lower than the discharge start voltage Vf, no discharge occurs between the sustain electrode and the scan electrode.

Various attempts have been made to improve image quality in such plasma display panels. There are a method of improving the black-room ratio to improve the bright room contrast, a method of reducing the reflected luminance to easily implement an image, and a method of improving the luminance by increasing the luminous efficiency.

In particular, in order to improve the black fraction, a black layer may be formed in a separate structure inside the panel. However, to provide a black layer as described above, a separate process must be added. Alternatively, the higher the size of the panel should be limited in the configuration that can be included therein, so the need for a technique that can improve the contrast of the clear room while eliminating or minimizing the separate configuration as described above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a plasma display panel having low reflectance, high black ratio, and good clear contrast without partitioning.

In order to achieve the above object, a plasma display panel according to the present invention includes a rear substrate facing a front substrate and colored in a first color, an address electrode formed to extend in the first direction on the rear substrate, and covering the address electrode; A back dielectric layer formed on the back substrate, a partition wall partitioning respective discharge cells between the front substrate and the back substrate, a phosphor layer formed inside the discharge cell, and a second direction crossing the first direction on the front substrate; And a front surface dielectric layer covering the display electrode and formed on the front substrate, wherein the front surface dielectric layer comprises a first layer colored with a second color and a second layer colored with a third color. And the first color, the second color, and the third color are each subtracted from each other.

In addition, in the plasma display panel according to the present invention, a color in which any two selected colors among the first color, the second color, and the third color are mixed is preferably in a complementary color relationship with the other color. In addition, the first color, the second color and the third color is preferably any one of the colors selected from among the three primary colors of the magenta (Cagenta), cyan (Yellow) and the yellow (Yellow) series of colors, respectively. . In addition, the front substrate is preferably a colorless transparent substrate. In addition, the partition wall is preferably made of a colorless transparent partition wall material.

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 may 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. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like elements throughout the specification.

1 is a perspective view schematically showing a plasma display panel according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1.

As shown, the plasma display panel includes a back substrate 10, an address electrode 11, a back dielectric layer 12, a partition 13, and a phosphor layer 14. In addition, the front substrate 16, the display electrode 17, the front dielectric layer 18, and the protective layer 19 are included.

The back substrate 10 and the front substrate 16 face each other. In particular, the front substrate 16 is not colored but transparent, visible light is easily transmitted, and the back substrate 10 is colored.

The address electrode 11 is formed on the upper surface of the rear substrate 10 in a first direction (y-axis in the figure). The address electrode 11 mainly uses Ag Paste and has a width of 70 to 80 µm. In addition, a back dielectric layer 12 is formed on an upper surface of the back substrate 10, and the back dielectric layer 12 covers the address electrode 11. The address electrode 11 must be chemically stable so as not to react with the back dielectric layer 12 and the back substrate 10.

The lower surface of the front substrate 16 is formed by extending the display electrode 17 in a second direction (x-axis in the figure). In addition, the display electrode 17 includes a scan electrode 17a and a sustain electrode 17b.

The image is displayed forward through the front substrate 16. At this time, the sustain electrode 17b and the scan electrode 17a are made of a transparent material to improve brightness. The transparent material is indium tin oxide (ITO), and is also called a transparent electrode because it is transparent.

A bottom dielectric layer 18 is formed on the bottom surface of front substrate 16, which includes a first layer 18a and a second layer 18b. In particular, the first layer 18a is formed closer to the front substrate 16 than the second layer 18b.

The front dielectric layer 18 protects the display electrode 17 from discharge phenomenon. In addition, it functions as a capacitor during discharge, prevents current from passing through, and functions as a memory to facilitate discharge in a specific discharge cell.

The front dielectric layer 18 is covered with a protective layer 19, which is usually formed of a transparent material to easily transmit visible light, protect the front dielectric layer 18 from discharge, and secondary electron emission coefficient Increase the so that the discharge start voltage can be lowered.

A partition 13 is formed between the protective layer 19 and the rear dielectric layer 12. The partition 13 includes a horizontal partition member 13a and a vertical partition member 13b. The horizontal partition member 13a is formed to extend in the second direction (x-axis in the drawing), and the vertical partition member 13b is formed to extend in the first direction (y-axis in the drawing), which is the horizontal partition member 13a. Cross). In the present embodiment, the horizontal partition member 13a and the vertical partition member 13b partition the discharge cells 15, and the discharge cells 15 have a lattice shape.

The discharge cells 15 according to the embodiment of the present invention may be formed in various forms such as a stripe or delta in addition to the lattice form.

The partition 13 prevents cross talk between the discharge cells 15. The partition wall 13 has a width of 50 to 100 μm and a height of 100 to 200 μm, and maintains a gap between the substrates and partitions the discharge cells 15.

Usually, the material of the partition 13 includes an organic solvent (resin / coloring agent) or a filler (aluminum, metal powder, etc.) in low-melting glass (Glass Paste), but in the embodiment of the present invention, no coloring agent is added. Therefore, it is characterized by a high strength compared to the partition walls added with the coloring agent.

In the reset period, the reset discharge is generated by the reset pulse applied to the scan electrode 17a. In the addressing period following the reset period, the scan pulse applied to the scan electrode 17a and the address pulse applied to the address electrode 11 are generated. This causes address discharge. In the sustain period thereafter, a sustain discharge is caused by a sustain pulse applied to the sustain electrode 17b and the scan electrode 17a. This sustain discharge excites the phosphor layer 14, and the phosphor layer 14 generates visible light, and this visible light is seen through the front substrate 16.

The back substrate 10 colored in yellow has a strong characteristic of reflecting rather than absorbing visible light. Therefore, the luminous efficiency of the visible light formed in the phosphor layer 14 of the discharge cell 15 increases.

As shown in the drawing, the display electrode 17 including the scan electrode 17a and the sustain electrode 17b is formed on the lower surface of the front substrate 16. The display electrode 17 is formed side by side along the discharge cell, and the bus electrode 20 is formed on the lower side of the display electrode 17. In addition, the first layer 18a, the second layer 18b, and the protective layer 19 are sequentially formed.

The bus electrode 20 is formed of a Cr-Cu-Cr film or an Ag film on the transparent electrode, and the bus electrode 20 has a high conductivity so that current can be easily applied to the display electrode 17, and the display electrode 17 and It should be chemically stable so as not to react with the front dielectric layer 18.

In the exemplary embodiment of the present invention, the display electrodes 17 are continuously formed, but it is obvious that the display electrodes 17 may be formed in the respective discharge cells 15 individually.

The partition 13 and the back dielectric layer 12 are not colored, have transparent characteristics, and they may be formed of the same material. In this case, the partition 13 and the rear dielectric layer 12 may be formed in a single process.

Since the pigments do not enter the uncolored partition 13, the ratio of TiO 2 is relatively high, thereby increasing the strength, thereby eliminating the problem that the phosphor layer 14 is damaged or defects are generated in the discharge cells. Extend the life of the panel.

In addition, the partition wall 13 and the back dielectric layer 12 that are not colored absorb less visible light, thereby increasing the luminous efficiency of the panel.

In addition, when the back substrate 10 is colored in yellow, since the visible light generated in the phosphor layer 14 is easily reflected, the light emission luminance of the panel may be increased.

In the exemplary embodiment of the present invention, the back substrate 10 is colored in the first color, and the first layer 18a and the second layer 18b are colored in the second color and the third color, respectively. In particular, the first color, the second color, and the third color may be any one selected from among the three primary colors of the colorants Magenta, Cyan, and Yellow, respectively.

3 is a plan view illustrating an image display area of a plasma display panel according to an exemplary embodiment of the present invention.

Referring to FIG. 3 according to an embodiment of the present invention, the same reference numerals are used for the same or similar parts as those of FIGS. 1 and 2, and repeated descriptions thereof will be omitted.

Referring to FIGS. 2 and 3, the plasma display panel has an image display area 30. For convenience of description, the image display area 30 shows only a part of the entire area.

The image display area 30 is divided into a first area 30a and a second area 30b. The first region 30a is a region where the first layer 18a and the second layer 18b overlap each other, and the second region 30b is the first layer 18a, the second layer 18b and the back substrate ( 10) is the overlapping area.

Therefore, when the first layer 18a and the second layer 18b are colored in magenta and cyan, respectively, and the back substrate 10 is colored in yellow, the first region 30a is colored. Is an area where magenta and cyan overlap each other, and the second area 30b is an area where magenta, cyan and yellow rain overlap each other.

4 is a view schematically showing the relationship between colors that appear when three primary colors of a color material overlap.

The three primary colors of the colors are Magenta, Yellow, and Cyan, and if these colors are properly mixed or superimposed, Red, Green, Blue, and Black It takes

Magenta is slightly blueish red (purple), cyan is slightly greenish blue (blue-green), and yellow is yellow. Proper mixing of these three-primary inks or overlapping filters can produce multiple colors. In addition, Blue is indigo blue with a blue series.

As shown in FIG. 4, when Yellow and Magenta overlap, Red becomes red, and when Yellow and Cyan overlap, Green becomes green, and Cyan and Magenta overlap. Overlapping magenta is blue. In addition, if Green and Magenta overlap, it becomes Black, and if Blue and Yellow overlap, it becomes Black. If Red and Cyan overlap, it becomes black. It becomes (Black).

Colors such as magenta, yellow and cyan are called primary colors. In addition, the color which subtracts and mixes arbitrary two colors among primary colors is called secondary color. That is, red, green, and blue are called secondary colors, and these colors are called three primary colors of color.

It is said that the relationship between the colors being mixed or overlapping becomes the achromatic color (White, Gray, Black). Green has a complementary color relationship with Magenta, Yellow has a complementary color relationship with Blue, and Red has a complementary color relationship with Cyan. In addition, magenta, yellow, and cyan are black when overlapped or mixed together, and thus they may be said to be complementary to each other.

Even if the color is not complementary, the subtractive color of the complementary color gives a dark color close to black.

As described above, when the first color of the back substrate 10, the second color of the first layer 18a and the third color of the second layer 18b are subtracted or overlapped, they have a dark color such as black. In addition, the first color, the second color, and the third color may be formed of three primary colors (Magenta, Cyan, Yellow) of different colorants, and all three primary colors of the colorant are primary colors.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications or changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. In addition, it is natural that it belongs to the scope of the present invention.

As described above, according to the plasma display panel according to the present invention, by coloring the first layer, the second layer, and the back substrate, the black portion of the panel increases, the clear room contrast increases, and the reflection brightness is reduced. .

In addition, the back substrate is colored with a color that easily reflects visible light, so that the brightness is increased, thereby facilitating an image.

In addition, the non-colored partition wall has a stronger strength than the colored partition wall, thereby preventing damage to the discharge cells and the phosphor layer.

Claims (5)

A back substrate facing the front substrate and colored in a first color; An address electrode formed on the rear substrate to extend in a first direction; A back dielectric layer covering the address electrode and formed on the back substrate; Barrier ribs that partition respective discharge cells between the front substrate and the rear substrate; A phosphor layer formed inside the discharge cell; A display electrode formed on the front substrate to extend in a second direction crossing the first direction; And A front dielectric layer covering the display electrode and formed on the front substrate; The front dielectric layer is A first layer colored in a second color; And A second layer colored in a third color, And the first, second and third colors are subtracted and mixed with each other. According to claim 1, And a color in which any two selected ones of the first color, the second color, and the third color are mixed is complementary to the other color. According to claim 1, The first color, the second color, and the third color may be any one of different colors selected from magenta, cyan, and yellow series colors, which are three primary colors of the colorant. According to claim 1, And the front substrate is a colorless transparent substrate. According to claim 1, And the partition wall is made of a colorless transparent partition material.

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