KR20070119907A - Plasma display panel - Google Patents

Abstract

A plasma display panel is provided to reduce an outdoor daylight reflection brightness and to improve an ambient contrast by coloring a second substrate with a brown color and forming a white color layer and a blue color layer on a bus electrode of a scan electrode. A first substrate and a second substrate(20) face to each other. The first and second substrates are separated from each other. A barrier rib is arranged between the both substrates to divide discharge cells. A fluorescent substance layer is formed on the discharge cell. An address electrode corresponds to the discharge cells to be formed in a first direction. First and second electrodes(31,32) are respectively formed in a second direction intersected in the first direction to correspond to the discharge cells. The first and second electrodes include transparent electrodes(31a,32a) and bus electrodes(31b,32b). The transparent electrodes form a discharge gap in the discharge cells. The bus electrodes are formed on the transparent electrodes in the second direction. The bus electrodes include white color layers and blue color layers. The second substrate is colored with a brown color.

Description

Plasma Display Panel {PLASMA DISPLAY PANEL}

1 is a perspective view schematically illustrating an exploded view of a plasma display panel according to an exemplary 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 showing an arrangement relationship between discharge cells and electrodes.

4 is a sectional view of the state in which the bus electrode and the front substrate are actually colored.

5 is a plan view showing the complementary color relationship of FIG.

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

10: first substrate (back substrate) 11: address electrode

13, 21: 1st, 2nd dielectric layer 16: partition wall

16a: first partition member 16b: second partition member

17 discharge cell 19 phosphor layer

20: second substrate (front substrate) 23: protective film

31: first electrode (holding electrode) 32: second electrode (scanning electrode)

31a, 32a: transparent electrode 31b, 32b: bus electrode

131b, 132b: white layer 231b, 232b: blue series layer

33: stripe BP: black series

BP1, BP2: First, second black series

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 that reduces external light reflection luminance and improves clear room contrast while implementing a predetermined blackness at low cost, such as a cobalt-based bus electrode.

In general, a plasma display panel is a visible light of red (R), green (G) and blue (B) generated by exciting the phosphor using a vacuum ultra-violet (VUV) emitted from the plasma obtained through gas discharge It is a display device for implementing an image.

As an example, an AC plasma display panel forms address electrodes on a rear substrate and covers the address electrodes with a dielectric layer. The partition walls are disposed between the address electrodes on the dielectric layer to form a stripe shape, and phosphor layers of red (R), green (G), and blue (B) layers are formed on the partition walls. On the front substrate facing the rear substrate, display electrodes composed of a pair of sustain electrodes and scan electrodes are formed along the direction crossing the address electrodes, and a dielectric layer and an MgO protective film cover the display electrodes. A discharge cell is formed at a point where the address electrodes on the rear substrate and the pair of display electrodes on the front substrate cross each other. In the plasma display panel, millions of unit discharge cells are arranged in a matrix form.

The memory characteristic is used to drive the discharge cells of the plasma display panel. In more detail, in order to generate a discharge between the sustain electrode and the scan electrode constituting the pair of display electrodes, a potential difference of more than a specific voltage is required, and the voltage at this boundary is called a firing voltage (Vf). When the scan voltage and the address voltage are respectively applied to the scan electrode and the address electrode, the discharge is started to form a plasma in the discharge cell, and the electrons and ions of the plasma move toward the electrodes having opposite polarities.

On the other hand, a dielectric layer is applied to each electrode of the plasma display panel, so that most of the moved space charges are stacked on the dielectric layer having opposite polarity, so that the net space potential between the scan electrode and the address electrode is originally applied to the address. It becomes lower than voltage Va, discharge becomes weak, and address discharge disappears. At this time, a relatively small amount of electrons are accumulated in the sustain electrode, and a relatively large amount of ions are accumulated in the scan electrode. The charges accumulated on the sustain electrode and the dielectric layer covering the scan electrode are wall charged (Qw). The space voltage formed between the sustain electrode and the scan electrode by these wall charges is referred to as wall voltage (Vw).

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. The vacuum ultraviolet (VUV) generated at this time excites the phosphor and emits visible light through the transparent front substrate.

However, when there is no address discharge between the scan electrode and the address electrode (that is, when no address voltage Va is 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, the gas space between the sustain electrode and the scan electrode cannot be discharged.

Various attempts have been made to improve the ratio of black in the driving of the plasma display panel driven as described above, that is, the black portion ratio, thereby improving the clear room contrast.

As an example, there is a technique in which the sustain electrode and the scan electrode are formed of the transparent electrode and the bus electrode, the bus electrode is formed of the black layer and the white layer, and the black layer ratio is improved with this black layer.

The black layer of the bus electrode is divided into ruthenium (Ru) and cobalt (Co). The ruthenium-based black layer realizes blackness in a small amount, thereby reducing external light reflection brightness and improving clear room contrast. Cobalt-based black layer is less expensive than ruthenium-based, and is used in a large amount to realize blackness, and even if a large amount is used, it does not reach the blackness of ruthenium-based.

In addition, a method of using a complementary color relationship has been developed. In the plasma display panel using this complementary color relationship, the entire dielectric layer of the front substrate is colored in blue, and the partition wall of the back substrate is colored in red.

However, this plasma display panel improves bright room contrast by coloring the partitions in a red series, but absorbs a lot of visible light generated in the discharge cells in the red partitions. Has a problem of lowering.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma display panel which reduces external light reflection luminance and improves clear room contrast while realizing a predetermined blackness at a low cost like a cobalt-based bus electrode.

According to an embodiment of the present invention, a plasma display panel includes a first substrate and a second substrate disposed to face each other, a partition wall disposed between the two substrates to partition discharge cells, a phosphor layer formed on the discharge cells, An address electrode formed in a first direction corresponding to the discharge cells, and a first electrode and a second electrode formed in a second direction crossing the first direction corresponding to the discharge cells, respectively; The first electrode and the second electrode include a transparent electrode forming a discharge gap with each other in the discharge cell, and a bus electrode formed in the second direction on the transparent electrodes, wherein the bus electrode includes a white layer and a blue color. Including a series layer, the second substrate may be colored in brown.

The blue series layer may include cobalt oxide.

In addition, the plasma display panel according to an exemplary embodiment of the present invention may include a blue based stripe formed in the second direction on the first substrate facing the discharge cells neighboring in the first direction. have.

The partition wall extends in the second direction between the first partition members and the first partition members that extend in the first direction and are formed at intervals corresponding to the discharge cells along the second direction. Second barrier rib members may be formed at intervals corresponding to the discharge cells along the first direction.

The second partition member may face each other with the blue stripes formed on the second substrate.

The blue series may include blue or indigo blue. The second substrate may include a rare earth oxide.

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

Referring to these drawings, the plasma display panel according to the exemplary embodiment is disposed on the first substrate (hereinafter referred to as a "back substrate") 10 and the second substrate which are disposed to face each other at predetermined intervals. (Hereinafter referred to as "front substrate") 20 and partition walls 16 provided between the substrates 10 and 20. The partition 16 is formed at a predetermined height between the rear substrate 10 and the front substrate 20 to partition the plurality of discharge cells 17. The discharge cells 17 are filled with a discharge gas (for example, a mixed gas including neon (Ne) and xenon (Xe)) so as to generate vacuum ultraviolet rays by gas discharge. The discharge cells 17 absorb the vacuum ultraviolet rays and display visible light. A phosphor layer 19 emitting light is provided.

The plasma display panel includes an address electrode 11 and a first electrode (hereinafter referred to as a “holding electrode”) corresponding to each discharge cell 17 between the rear substrate 10 and the front substrate 20 in order to realize an image by gas discharge. 31 and a second electrode (hereinafter referred to as "scan electrode") 32 are provided.

As an example, the address electrode 11 is formed along the first direction (y-axis direction in the drawing) on the inner surface of the back substrate 10 to form discharge cells 17 adjacent to the y-axis direction. Corresponds continuously. In addition, the plurality of address electrodes 11 are arranged side by side to correspond to the discharge cells 17 adjacent to each other in a second direction (the x-axis direction in the drawing) that crosses the y-axis direction.

The address electrodes 11 are covered with the first dielectric layer 13 covering the inner surface of the back substrate 10 as described above. The first dielectric layer 13 prevents cations or electrons from directly colliding with the address electrode 11 during discharge, thereby preventing damage to the address electrode 11, and also forms and accumulates wall charges. Since the address electrode 11 is disposed on the rear substrate 10 and does not prevent the visible light from being irradiated forward, the address electrode 11 may be formed of an opaque electrode, that is, a metal electrode having excellent electrical conductivity.

The partition 16 is actually provided on the first dielectric layer 13 to partition the discharge cells 17. The partition 16 includes first partition members 16a extending in the y-axis direction and second partition members 16b extending in the x-axis direction between the first partition members 16a. In addition, the discharge cells 17 are formed in a matrix structure.

In addition, the partition wall may be formed of first partition wall members extending in the y-axis direction to form discharge cells in a stripe structure (not shown). That is, the discharge cells form a structure that is open along the y-axis direction.

In this embodiment, the partition wall 16 forming the discharge cells 17 in a matrix structure is illustrated. In this state, when the second partition wall members 16b are removed, the partition wall structure is formed by the first partition wall members 16a. Discharge cells are formed. Therefore, a separate illustration of the discharge cells of the stripe structure is omitted here.

The phosphor layer 19 formed in each of the discharge cells 17 is coated with a phosphor paste on the side of the partition 16 and the surface of the first dielectric layer 13 positioned between the partitions 16. It is formed by drying and firing.

The phosphor layer 19 is formed of phosphors of the same color in the discharge cells 17 formed along the y-axis 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 17 repeatedly arranged along the x-axis direction.

On the other hand, referring to Figure 3, the sustain electrode 31 and the scanning electrode 32 is provided on the inner surface of the front substrate 20, each discharge cell 17 to cause gas discharge in the discharge cells 17 In response to the surface discharge structure is formed. The sustain electrode 31 and the scan electrode 32 extend in the x-axis direction crossing the address electrode 11.

The sustain electrode 31 and the scan electrode 32 each include transparent electrodes 31a and 32a for generating a discharge and bus electrodes 31b and 32b for applying a voltage signal to the transparent electrodes 31a and 32a, respectively. Is formed. The transparent electrodes 31 a and 32 a are portions which cause surface discharge inside the discharge cell 17 and are formed of a transparent material (for example, indium tin oxide (ITO)) to secure the aperture ratio of the discharge cell 17. The bus electrodes 31b and 32b are formed of a metal material having excellent electrical conductivity to compensate for the high electrical resistance of the transparent electrodes 31a and 32a.

The transparent electrodes 31a and 32a form surface discharge structures with each of the widths W31 and W32 from the outer edge of the discharge cell 17 along the y-axis direction, and form a center portion of each discharge cell 17. Discharge gap DG is formed. The bus electrodes 31b and 32b are disposed on the transparent electrodes 31a and 32a, respectively, and extend in the x-axis direction at the outside of the discharge cell 17. Therefore, when the voltage signal is applied to the bus electrodes 31b and 32b, the voltage signal is applied to each of the transparent electrodes 31a and 32a connected to the bus electrodes 31b and 32b.

Referring back to FIGS. 1 and 2, the sustain electrode 31 and the scan electrode 32 are covered with the second dielectric layer 21 while crossing the address electrodes 11 and facing each other corresponding to the discharge cells 17. Lose. The second dielectric layer 21 forms and accumulates wall charges during discharge while protecting the sustain electrode 31 and the scan electrode 32 from gas discharge.

The second dielectric layer 21 is covered with the protective film 23. For example, the passivation layer 23 is formed of transparent MgO protecting the second dielectric layer 21 to increase the secondary electron emission coefficient during discharge.

During the plasma display panel driving, a reset discharge is generated by a reset pulse applied to the scan electrode 31 in the reset period, and the scan pulse and the address electrode 11 applied to the scan electrode 32 in the addressing period following the reset period. The address discharge is caused by an address pulse applied to the? Thereafter, in the sustain period, sustain discharge is caused by a sustain pulse applied to the sustain electrode 31 and the scan electrode 32.

The sustain electrode 31 and the scan electrode 32 serve as electrodes for applying sustain pulses required for sustain discharge, and the scan electrodes 32 serve as electrodes for applying reset pulses and scan pulses, and the address electrodes. Reference numeral 11 serves as an electrode for applying an address pulse. Since the sustain electrode 32, the scan electrode 32, and the address electrode 11 may have different roles depending on voltage waveforms applied to the sustain electrodes 32, the scan electrodes 32, and the address electrodes 11 are not necessarily limited to these roles.

The plasma display panel selects a discharge cell 17 to be turned on by the address discharge due to the interaction between the address electrode 11 and the scan electrode 32, and the interaction between the sustain electrode 31 and the scan electrode 32. The selected discharge cell 17 is driven by sustain discharge, thereby realizing an image.

On the other hand, the plasma display panel of the present embodiment is configured such that cobalt (Co) bus electrodes 31b and 32b have a predetermined blackness at low cost, thereby reducing external light reflection luminance and improving clear room contrast. .

Subsequently, referring to Figs. 4 and 5, the present embodiment does not form black portions due to the complementary color relationship, but instead of black portions BBP which are partially black on the whole of the plasma display panel. Form.

This black-based part BP has a disadvantage in that it is somewhat disadvantageous in reducing external light reflection brightness and improving clear contrast compared to pure black, but may also have an advantage of minimizing the blocking of visible light emitted from the discharge cells 17.

Referring back to FIG. 2, the bus electrodes 31b and 32b include white layers 131 and 132 and blue series layers 231 and 232. The white layers 131 and 132 are formed on the blue series layers 231 and 232, respectively. The white layers 131 and 132 include silver (Ag) and have excellent electrical conductivity, and are responsible for the electrical conductivity of the bus electrodes 31b and 32b.

Referring to FIG. 4, the blue series layers 231 and 232 of the bus electrodes 31b and 32b are formed by coloring the blue series. The blue series layers 231 and 232 form black-based portions BP in the plasma display panel to reduce external light reflection luminance and improve clear room contrast.

In addition, the blue series layers 231 and 232 include cobalt (Co) oxides, and are colored in blue series as a whole, thereby reducing the consumption of cobalt for implementing black. This further reduces manufacturing costs.

The front substrate 20 is colored brown to form a complementary color relationship with the blue series layers 231 and 232 of the bus electrodes 31b and 32b to form the black base portion BP of the plasma display panel.

The front substrate 20 is colored brown to absorb external light while blocking a part of the visible light irradiated from the discharge cells 17.

However, referring to FIG. 5, the brown series part BP of the brown of the front substrate 20 and the blue series layers 231 and 232 of the bus electrodes 31b and 32b form the black part BP. This is called a first black part BP1. The first black system portion BP1 absorbs external light to reduce external light reflection latitude.

On the other hand, the plasma display panel further includes a blue-based stripe 33 to increase the black-based portion BP. The blue stripe 33 extends in the x-axis direction on the front substrate 20 facing between the discharge cells 17 adjacent to each other in the y-axis direction to form the black-based portion BP in the non-display area. . This is called a second black part BP2. Unlike the first black system BP1 that blocks visible light, the second black system BP2 absorbs external light without blocking visible light.

The blue stripe 33 is formed to face the second partition member 16b. That is, the second black system part BP2 is formed to face the second partition member 16b which is a non-display area.

In this embodiment, the blue series may include blue and indigo colors and similar colors, and include colors substantially forming a complementary color relationship with brown colored on the front substrate 20.

In addition, the front substrate 20 forming a complementary color relationship with the blue series of the bus electrodes 31b and 32b includes an additive for coloring. As an example, the additive includes a rare earth oxide.

Since the front substrate 20 including the rare earth-based oxide has a side effect of blocking infrared rays, the near-infrared cutoff is provided to block near-infrared rays in a direct-attach filter (not shown) having a multi-layered structure. Allows removal of layers (not shown).

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

As described above, in the plasma display panel according to the present invention, the second substrate (front substrate) to which visible light is irradiated is colored brown, and a white layer and a blue series layer are provided on the sustain electrode and the bus electrode of the scan electrode, and the brown color is brown. The black system based on the complementary color relationship between the blue and the blue series can realize the reduction of the external light reflection luminance and the improvement of the clear room contrast. In addition, the plasma display panel according to the present invention further includes a blue-based stripe between neighboring discharge cells, and can effectively reduce external light reflection luminance and improve clear room contrast with a black system using a complementary color relationship with brown of the substrate. have.

Claims (7)

A first substrate and a second substrate spaced apart from each other; Barrier ribs disposed between the substrates to partition discharge cells; A phosphor layer formed on the discharge cell; An address electrode formed in a first direction corresponding to the discharge cells; And A first electrode and a second electrode respectively formed in a second direction crossing the first direction to correspond to the discharge cells; The first electrode and the second electrode, A transparent electrode forming a discharge gap with each other in the discharge cell; A bus electrode formed on the transparent electrodes in the second direction, The bus electrode includes a white layer and a blue series layer, And the second substrate is colored brown. According to claim 1, The blue series layer includes cobalt oxide. According to claim 1, And a blue series stripe formed in the second direction on the first substrate facing each other between the discharge cells neighboring in the first direction. According to claim 1, The partition wall, First barrier members extending in the first direction and formed at intervals corresponding to the discharge cells along the second direction; And second partition members extending in the second direction between the first partition members and formed at intervals corresponding to the discharge cells along the first direction. The method of claim 4, wherein The second barrier member faces the blue stripes formed on the second substrate. According to claim 1, The blue series includes a blue or indigo blue. According to claim 1, And the second substrate comprises a rare earth oxide.

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