KR100804694B1 - Plasma display panel - Google Patents

Abstract

A plasma display panel is provided to improve image quality of the display panel by preventing interference between adjacent pixels. A plasma display panel includes first and second substrates(10,20), a barrier rib(16), an address electrode(12), a display electrode, a fluorescent layer(19), and a dielectric layer(28). The first and second substrates are arranged to be apart from each other. The barrier rib is arranged between the first and second substrates and defines discharge cells. The address electrode is elongated in a first direction corresponding to the discharge cells on the first substrate. The display electrode is elongated in a second direction, which is normal to the first direction, corresponding to the discharge cells on the second substrate. The fluorescent layer is formed along the first direction. A color of the fluorescent layer is changed along the second direction. The dielectric layer covers the display electrode on the second substrate. The dielectric layer includes first and second refractive members. The first refractive member corresponds to an edge of the pixels according to the color of the respective fluorescent layers. The second refractive member corresponds to a region except for the first refractive member, and has a refractive index greater than that of the first refractive member.

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.

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

3 is a plan view illustrating an arrangement relationship between a first refractive member and a second refractive member constituting a dielectric layer of a plasma display panel according to an exemplary embodiment of the present invention.

4 is a cross-sectional view illustrating a shape relationship between a dielectric layer and a partition of a plasma display panel according to an exemplary embodiment of the present invention.

FIG. 5 is a diagram illustrating a visible light refractive index relationship between a dielectric layer and a front substrate of a plasma display panel according to an exemplary embodiment of the present invention.

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

10; Back substrate 20; Front board

16; Bulkhead 28; Dielectric layer

28a; First refracting member 28b; Second refracting member

28a1; First material member 28a2; Second material member

The present invention relates to a plasma display panel, and more particularly, to a plasma display panel which can improve the display quality of a plasma display panel by reducing the spreading of visible light excited from a phosphor layer inside a discharge cell to an adjacent pixel. will be.

Typically, a plasma display panel is formed of red (R), green (G), and blue (B) generated by exciting a phosphor using vacuum ultraviolet (VUV) emitted from a plasma generated through gas discharge. Implement the image with visible light.

The plasma display panel is classified into a direct current type and an alternating current type according to the applied driving voltage and the structure of the discharge cell, and a schematic configuration of an alternating current plasma display panel (hereinafter referred to as a "plasma display panel") will be described. .

First, address electrodes are formed on a rear substrate, and the address electrodes are covered with a dielectric layer. The partition walls are disposed between the address electrodes on the dielectric layer to form a stripe or matrix shape. The front substrate is spaced apart from the rear substrate so as to face each other, and display electrodes including a pair of sustain electrodes and scan electrodes are formed along a direction crossing the address electrodes. The display electrode is covered with a dielectric layer and a protective film (MgO protective film). A discharge cell is formed at a point where the pair of address electrodes on the rear substrate and the pair of display electrodes on the front substrate cross each other. Phosphor layers of red (R), green (G), and blue (B) are formed inside the discharge cell. As described above, a phosphor layer of each color is formed in a corresponding discharge cell to form a red discharge cell, a green discharge cell, and a blue discharge cell, and the red discharge cell, the green discharge cell, and the blue discharge cell each emit one set of light emission. A pixel is formed as a unit.

In the above-described plasma display panel, millions of unit discharge cells are arranged in a matrix form, and an image necessary for discharging the selected discharge cells among these discharge cells is displayed.

By the way, when the above-described method is used, while the plasma display panel according to the prior art displays an image on the front surface, external light generated from various light sources is incident on the front surface of the plasma display panel.

In this case, the external light incident on the front surface of the plasma display panel is partially reflected from the front surface of the plasma display panel and mixed with the visible light displayed by the plasma display panel, thereby degrading the display performance of the image actually expressed by the plasma display panel.

In addition, visible light is refracted and reflected at each interface where the passivation layer, dielectric layer, and front substrate are formed, and the visible light is scattered and transmittance is decreased. The visible light is increased or the visible light is spread to adjacent pixels by total reflection of the visible light. There is a problem that a halation phenomenon occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma display panel which can reduce the phenomenon in which visible light is spread to adjacent pixels, thereby improving display performance degradation of the plasma display panel due to the spread of visible light.

In order to achieve the above object, the present invention provides a barrier rib disposed between a first substrate and a second substrate spaced apart from each other, and a partition wall disposed between the first substrate and the second substrate to partition each discharge cell, from the first substrate to each discharge cell. A corresponding address electrode extending in the first direction, a display electrode extending in the second direction corresponding to each discharge cell on the second substrate, and extending in a second direction crossing the first direction, and repeating in different colors along the second direction A red, green and blue phosphor layer formed on the discharge cells in the same color along the first direction, and a dielectric layer covering the display electrode on the second substrate, wherein the dielectric layer is formed according to the color of each phosphor layer. It is preferable to include a first refractive member corresponding to the boundary region of, a second refractive member corresponding to a region other than the first refractive member and having a refractive index different from that of the first refractive member.

In the above configuration, the first refractive member has a smaller refractive index than the second refractive member.

The first refractive member may correspond to the partition wall.

The partition wall may include a first partition member formed in a first direction and a second partition member formed in a second direction crossing the first partition member.

The first refractive member forms a boundary between the blue discharge cell and the red discharge cell, and is formed in a first material member corresponding to the first partition member, in a second direction crossing the first material member, and corresponding to the second partition member. It may include a second material member to be.

The first material member may be repeatedly disposed along the second direction, and may be repeatedly disposed along the first direction.

The first material member and the second material member have the same refractive index with each other.

The dielectric layer may have the same refractive index as the front substrate or may have a smaller refractive index than the front substrate.

The second refractive member has the same refractive index as the front substrate.

The width of the first refractive member may be equal to the width of the partition wall.

The width of the partition wall is formed differently from the top width and the bottom width, the top width may be formed smaller than the bottom width.

The width of the first refracting member may be formed to be equal to the top width of the partition wall or smaller than the width of the partition wall.

The width of the first refractive member may be smaller than the top width of the partition wall.

The height of the first refracting member may be the same as the height of the second refracting member.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. While many specific details are set forth in order to provide a more general understanding of the invention, such as the following description and the annexed drawings, these specific details are illustrated for the purpose of illustrating the invention and are meant to limit the invention to those details. It is not. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

1 is a partial exploded attempt of a plasma display panel according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1.

A configuration of a plasma display panel according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The plasma display panel is disposed on the lower surface of the first substrate 10 (hereinafter referred to as a "back substrate"), the second substrate (hereinafter referred to as a "front substrate"), and the front substrate 20 which are disposed to face each other at a predetermined interval. A dielectric layer 28 formed to cover the substrate 20.

In order to implement an image by gas discharge, the plasma display panel displays the address electrode 12 and the address electrode 12 so as to correspond to each discharge cell 18 (18R, 18G, 18B) between the rear substrate 10 and the front substrate 20. The sustain electrode 21 and the scan electrode 22 which form an electrode are provided.

The address electrode 12 extends along the first direction (y-axis direction in the drawing) on the inner surface of the back substrate 10 and continuously corresponds to the discharge cells 18 adjacent in the first direction. . In addition, the plurality of address electrodes 12 are arranged side by side to correspond to adjacent discharge cells 18 in a second direction (the x-axis direction of the drawing) that crosses the first direction. Since the address electrode 12 is disposed on the rear substrate 10 and does not prevent the visible light from being irradiated forward, the address electrode 12 may be formed of an opaque electrode (that is, a metal electrode having excellent conductivity). The address electrode 12 is disposed on the inner surface of the back substrate 10 and covered with the dielectric layer 14. The dielectric layer 14 prevents cations or electrons from directly colliding with the address electrode 12 during discharge, thereby preventing damage to the address electrode 12 and forming and accumulating wall charges.

A partition wall 16 is formed between the back substrate 10 and the front substrate 20. The partition wall 16 is formed at a predetermined height on the dielectric layer 14 to partition the plurality of discharge cells 18. In the discharge cell 18 partitioned through the partition wall 16, a discharge gas (eg, a mixed gas including neon (Ne) and xenon (Xe)) is filled to generate vacuum ultraviolet rays by gas discharge. A phosphor layer 19 for absorbing vacuum ultraviolet light and emitting visible light is provided. As shown in FIG. 1, the partition wall 16 includes a first partition member 16a formed in a first direction and a second partition member 16b formed in a second direction perpendicular to the first partition member 16a. ), The discharge cells 18 are formed in a matrix structure. In addition, the partition wall may be formed to extend in the first direction, and the plurality of partition walls may be disposed side by side in the second direction to form discharge cells in a stripe structure (not shown).

The phosphor layer 19 formed in each of the discharge cells 18 is formed by applying a phosphor paste on the side surface of the partition wall 16 and the surface of the dielectric layer 14 and firing it. The phosphor layer 19 is formed of phosphors of the same color in the discharge cells 18 formed along the first direction. In addition, the phosphor layer 19 is repeatedly formed by the phosphors of red (R), green (G), and blue (B) in the discharge cells 18 repeatedly arranged along the second direction. The phosphor layer 19 may be divided into a red phosphor layer 19R, a green phosphor layer 19G, and a blue phosphor layer 19B.

The dielectric layer 28 according to the embodiment of the present invention includes a first refractive member 28a and a second refractive member 28b formed of a medium having different refractive indices.

Meanwhile, a sustain electrode 21 and a scan electrode 22 are formed on the bottom surface of the front substrate 20, and the sustain electrode 21 and the scan electrode 22 cross the address electrodes 12 to discharge cells 18. Are covered with a dielectric layer 28 facing each other.

The dielectric layer 28 forms and accumulates wall charges during discharge while protecting the sustain electrode 21 and the scan electrode 22 from gas discharge. The dielectric layer 28 is covered with the protective film 29. The passivation layer 29 is formed of magnesium oxide (MgO) that protects the dielectric layer 28 to increase the secondary electron emission coefficient upon discharge.

The sustain electrode 21 and the scan electrode 22 are provided on the inner surface of the front substrate 20 to form a surface discharge structure corresponding to each discharge cell 18 so as to cause gas discharge in the discharge cell 18. . The sustain electrode 21 and the scan electrode 22 extend in a second direction crossing the address electrode 12.

Each of the sustain electrodes 21 and the scan electrodes 22 includes transparent electrodes 21a and 22a for generating a discharge and bus electrodes 21b and 22b for applying a voltage signal to the transparent electrodes 21a and 22a, respectively. do. Each of the transparent electrodes 21a and 22a is a part which causes surface discharge in the discharge cell 18, and is a transparent material (eg, indium tin oxide, ITO) to secure the aperture ratio of the discharge cell 18. Is formed. The bus electrodes 21b and 22b are formed of a metal material having excellent conductivity to compensate for the high electrical resistance of the transparent electrodes 21a and 22a.

In the driving of the plasma display panel having the above-described configuration, in the reset period, reset discharge is caused by a reset pulse applied to the scan electrode 22. In the addressing period following the reset period, address discharge is caused by a scan pulse applied to the scan electrode 22 and an address pulse applied to the address electrode 12. Thereafter, in the sustain period, sustain discharge is caused by a sustain pulse applied to the sustain electrode 21 and the scan electrode 22.

The sustain electrodes 21 and the scan electrodes 22 serve as electrodes for applying sustain pulses required for sustain discharge, and the scan electrodes 22 serve as electrodes for applying reset pulses and scan pulses. The address electrode 12 serves as an electrode for applying an address pulse. The sustain electrode 21, the scan electrode 22, and the address electrode 12 may have different roles depending on voltage waveforms applied to the sustain electrode 21, the scan electrode 22, and the address electrode 12, respectively.

The plasma display panel selects a discharge cell 18 to be turned on by the address discharge due to the interaction between the address electrode 12 and the scan electrode 22, and the interaction between the sustain electrode 21 and the scan electrode 22. An image is realized by driving the selected discharge cells 18 by the sustain discharge.

3 is a plan view illustrating an arrangement relationship between a first refractive member and a second refractive member constituting a dielectric layer of a plasma display panel according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the first refractive member 28a is formed at a position corresponding to the boundary region of each pixel formed according to the color of each phosphor layer 19R, 19G, and 19B, and the second refractive member 28b is provided. Is formed in the remaining portions except for the first refractive member 28a.

The first refractive member 28a includes a first material member 28a1 and a second material member 28a2.

The first material member 28a1 is formed at a portion of the portion corresponding to the first partition member 16a that forms a boundary between the blue discharge cell 18B and the red discharge cell 18R. That is, it is preferable that the first material member 28a1 is not formed at all portions corresponding to the first partition wall member 16a, but only at portions that distinguish each pixel. Accordingly, the first material member 28a1 is a portion forming the boundary between the red discharge cell 18R and the green discharge cell 18G among the portions corresponding to the first partition member 16a, and the green discharge cell 18G and blue. It is not formed in the part which forms the boundary of the discharge cell 18B. The first material member 28a1 is repeatedly arranged along the second direction.

The second material member 28a2 is formed in a second direction crossing the first material member 28a1 and is formed in all portions corresponding to the second partition wall member 16b. The second material member 28a2 is repeatedly arranged along the first direction.

4 is a cross-sectional view illustrating a shape relationship between a dielectric layer and a partition of a plasma display panel according to an exemplary embodiment of the present invention.

The partition wall 16 of the present invention may be formed differently in the width of the top and bottom in the height direction. For example, as shown in FIG. 4, the upper width w2 of the partition wall 16 may be formed in a trapezoidal shape smaller than the lower width w3 of the partition wall 16. In this case, the width w1 of the first refractive member 28a may be formed to have a correlation with the width of the partition wall 16. For example, the width w1 of the first refractive member 28a may be formed to be equal to the top width w2 of the first partition member 16a. In addition, the width w1 of the first refractive member 28a may be smaller than the top width w2 of the first partition member 16a. Meanwhile, the height h1 of the first refractive member 28a may be the same as the height h2 of the second refractive member 28b.

FIG. 5 is a diagram illustrating a visible light refractive index relationship between a dielectric layer and a front substrate of a plasma display panel according to an exemplary embodiment of the present invention.

The index of refraction is represented by the value of the constant n in Snell's law (the law of refraction), which is established between the angle of incidence and the angle of refraction when light refracts at the interface of two isotropic media, and the light refracts when light travels from one material to another The degree to which it breaks. The refractive index is different depending on the type of material. For the same material, the refractive angle is different when the incident angle is different, but the refractive index is constant. When light is incident on the interface between two media having a difference in refractive index, the reflectance becomes larger as the difference between the refractive indices of the two materials and the larger the angle of incidence.

For example, when light enters a medium having a low refractive index into a medium having a high refractive index, the angle of refraction always becomes larger than the angle of incidence.

According to the embodiment of the present invention, the first refractive member 28a forming the dielectric layer 28 is formed with a smaller refractive index than the second refractive member 28b. That is, the refractive index n1a of the first refractive member 28a and the refractive index n1b of the second refractive member 28b have a relationship of n1a <n1b. The first material member 28a1 and the second material member 28a2 constituting the first refractive member 28a may be formed to have the same refractive index.

For the above reason, when the incident angles of visible light incident on the first refracting member 28a and the second refracting member 28b are the same, the refractive angle of the first refracting member 28a having a relatively small refractive index is equal to that of the second refracting member ( Larger than the refractive angle in 28b).

On the other hand, the visible light generated in each pixel passes through the dielectric layer 28 having a different angle of incidence. However, as shown in FIG. 5, the incident angle θa1 of the visible light incident on the second refractive member 28b in the red discharge cell 18R and the second refracting member 28b in the green discharge cell 18G are incident. When the incident angles θb1 of the visible light are the same, the angles of refraction θa2 and θb2 of the visible light refracted by the second refraction member 28b are the same. The incident angle θa3 of the visible light incident on the first refracting member 28a is equal to the incident angle θb2 of the visible light incident on the second refracting member 28b. In this case, when the refractive index n1a of the first refractive member 28a is configured to be smaller than the refractive index n1b of the second refractive member 28b, the refractive angle θa4 of the visible light refracted by the first refractive member 28a is set to the first. 2 is different from the refractive angle of the visible light refracted by the refracting member 28b. The incidence angles of the visible light incident on the front substrate 20 through the refractive members are also different from each other.

On the other hand, the visible light passes through the first refractive member 28a and the second refractive member 28b constituting the dielectric layer 28, respectively, and the first refractive index is small through the second refractive member 28b having a relatively large refractive index. The visible light propagating to the refracting member 28a has a critical incidence angle θa3 at which total reflection occurs at its interface. The critical incident angle θa3 is determined by the ratio of the refractive index n1b of the second refractive member 28b to the refractive index n1a of the first refractive member 28a.

If the incident angle is smaller than the critical incident angle θa3, the visible light is partially reflected at the interface between the first refracting member 28a and the second refracting member 28b, and the remainder is refracted at a larger refracting angle than the incident angle. The first refractive member 28a is transmitted through.

However, when the incident angle of the visible light forms the critical incidence angle θa3, the visible light has a 90 ° refracting angle parallel to the interface between the first refracting member 28a and the second refracting member 28b (①). In this case, the angle of refraction θa5 of the visible light refracted into the atmosphere through the front substrate 20 becomes larger than the angle of incidence (0 °). This is because the refractive index n2 of the front substrate 20 is larger than the refractive index of the atmosphere.

When the incident angle of the visible light exceeds the critical incident angle θa3, the visible light has the same reflection angle θa4 as the incident angle and total reflection is performed in the pixel inner direction (②). In this case, the angle of refraction θa7 of the visible light refracted into the atmosphere through the front substrate 20 is larger than the angle of incidence θa6.

Therefore, when the incident angle of the visible light is greater than or equal to the critical incidence angle θa3, the visible light does not pass through the first refraction member 28a, thereby reducing the phenomenon of spreading visible light to discharge cells of adjacent pixels (halation phenomenon).

For this reason, it is preferable that the embodiment of the present invention allows total reflection to occur in the first refraction member 28a to collect visible light emitted in the pixel into the pixel. In addition, it is preferable that the incident angle (critical incidence angle) of the visible light incident on the first refractive member 28a is made smaller to increase the total reflection effect. To this end, it is preferable to further increase the difference between the refractive index n1a of the first refractive member 28a and the refractive index n1b of the second refractive member 28b.

As described above, when the refractive indexes of the dielectric layers 28 are different from each other, the refractive index n1a of the first refractive member 28a corresponding to the boundary region of each pixel is determined by the second refractive member 28b. It is made smaller than the refractive index n1b, and makes the difference of the refractive index n1a of the 1st refractive member 28a and the refractive index n1b of the 2nd refractive member 28b further larger. Thus, the visible light is totally reflected inside the pixel in the first refraction member 28a, thereby reducing the phenomenon of the visible light spreading to neighboring pixels through the boundary region of each pixel.

Meanwhile, in the plasma display panel according to the exemplary embodiment of the present invention, as shown in FIG. 5, the refractive index n2 of the front substrate 20 and the refractive index n1b of the second refractive member 28b may be the same. .

The general glass material mainly used for the front substrate 20 has a refractive index of 1.52 and a standard atmospheric refractive index of 1.00029. In this case, the critical angle of incidence at the interface between the front substrate 20 and the atmosphere is approximately 40 degrees.

The front substrate 20 according to the embodiment of the present invention may use a high density glass material to make the refractive index larger than that of the ordinary glass material. As described above, the front substrate 20 is preferably made of a glass material having a refractive index larger than that of the glass material. By the way, this invention is not necessarily limited to this, The transmittance | permeability of visible light can be improved also with the structure of the glass material which can transmit visible light.

On the other hand, the detailed description of the present invention has been described with reference to specific embodiments, of course, various modifications are possible without departing from the scope of the invention.

For example, the refractive index n1 of the dielectric layer 28 may be smaller than the refractive index n2 of the front substrate 20. In this case, even though the incident angles of the visible light incident on the front substrate 20 through the dielectric layer 28 have the same angle, the angles of refraction of the visible light passing through the interface may be different from each other.

That is, when the refractive index n1 of the dielectric layer 28 is smaller than the refractive index n2 of the front substrate 20, the visible light has a higher refractive index from the dielectric layer 28 having a lower refractive index than the front substrate 20. Since the light is transmitted in the direction of the front substrate 20, the refractive angle is smaller than the incident angle.

As such, when the visible light is transmitted through the dielectric layer 28 to the front substrate 20 and the refractive angle becomes smaller than the incident angle, the visible light is transmitted closer to the linear light, thereby increasing the transmittance of the visible light. This is because the visible light is gradually refracted by the medium having a small refractive index and transmitted to the medium having a large refractive index, and is displayed to be refracted close to linear light.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below but also by the equivalents of the claims.

As described above, the plasma display panel according to the present invention can improve the visible light refractive index of the dielectric layer so that the visible light does not interfere with each other through the dielectric layer covering the display electrode, thereby reducing the halation phenomenon in which the visible light is spread to neighboring pixels. In addition, there is an effect that can improve the display performance of the plasma display panel.

Claims (11)

A first substrate and a second substrate spaced apart from each other; Barrier ribs disposed between the first substrate and the second substrate to partition respective discharge cells; An address electrode extending from the first substrate in a first direction corresponding to each of the discharge cells; A display electrode extending from the second substrate in a second direction perpendicular to the first direction corresponding to each of the discharge cells; Red, green, and blue phosphor layers formed in the discharge cells in the same color along the first direction and repeated in different colors along the second direction; And A dielectric layer covering the display electrode on the second substrate; The dielectric layer A first refractive member corresponding to a boundary region of each pixel formed according to the color of each phosphor layer; And And a second refractive member corresponding to a region other than the first refractive member and having a refractive index greater than that of the first refractive member. delete The method of claim 1, The first refractive member corresponds to the partition wall. The method of claim 3, The partition wall may include a first partition member formed in the first direction; And a second partition member formed in a second direction perpendicular to the first partition member. The method of claim 4, wherein The first refractive member is A first material member forming a boundary between the blue discharge cell and the red discharge cell and corresponding to the first partition member; And a second material member formed in a second direction perpendicular to the first material member and corresponding to the second partition member. The method of claim 5, And the first material member is repeatedly disposed along the second direction. The method of claim 5, And the second material member is repeatedly disposed along the first direction. The method of claim 5, And the first material member and the second material member have the same refractive index. delete The method of claim 1, And the dielectric layer has a smaller refractive index than the front substrate. The method of claim 1, The second refractive member has the same refractive index as the front substrate.

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