KR20080000866A - Plasma display panel - Google Patents

Abstract

A plasma display panel is provided to improve a contrast and a brightness of the display panel by increasing a ratio of a size of a black layer to the size of a white layer on a bus electrode. First and second substrates(2,4) are arranged to face each other with a constant distance. A barrier rib(6) is arranged between the substrates to define discharge cells. A fluorescent layer(10) is formed in the discharge cell. An address electrode(12) is formed along a first direction on the first substrate. First and second electrodes(14,16) are formed in a second direction on the second substrate. The second direction is vertical to the first direction. A dielectric layer(20) covers the first and second electrodes and is formed on the second substrate. The first and second electrodes include bus electrodes(142,162) formed on edge portions of the discharge cells. The bus electrode includes black and white layers. The black layer is wider than the white layer.

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.

FIG. 3 is a partially enlarged plan view of a front substrate of the plasma display panel shown in FIG. 1.

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

2: first substrate (back substrate) 4: second substrate (front substrate)

6: partition wall 8: discharge cell

10 phosphor layer 12 address electrode

14: first electrode (holding electrode) 16: second electrode (scanning electrode)

141,161: transparent electrode 142,162: bus electrode

142a, 162a: Black layer 142b, 162b: White layer

18: first dielectric layer 20: second dielectric layer

22: shield 24: home

The present invention relates to a plasma display panel, and more particularly, to a plasma display panel that can improve the contrast of a screen by improving the shape of a 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 back substrate and covers the address electrodes with a dielectric layer. The barrier ribs 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) are formed on the barrier ribs. On the front substrate facing the rear substrate, display electrodes composed of a pair of sustain electrodes and scanning electrodes are formed along the direction crossing the address electrodes, and a dielectric layer and an MgO protective film cover the display electrodes. The discharge cell is formed at the point where the pair of 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 accumulated 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. The voltage becomes lower than the voltage Va, the discharge is weakened, and the address discharge is extinguished. 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 dielectric layer covering the sustain electrode and the scan electrode are wall charged (Qw). The space voltage formed between the sustain electrode and the scan electrode by these wall charges is called a 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 corresponding 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 the address voltage Va is not applied), wall charges do not accumulate between the sustain electrode and the scan electrode, and as a result, between the sustain electrode and the scan electrode. The wall voltage does not exist. 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. .

In the plasma display panel having the above-described structure, each of the sustain electrode and the scan electrode is made of a transparent material such as ITO and includes a transparent electrode provided for generating a discharge, and a bus electrode for applying a voltage signal to the transparent electrode. Since the bus electrode is made of a metal material having excellent electrical conductivity to compensate for the high electrical resistance of the transparent electrode, the bus electrode is formed with a minimum width at the edge of the discharge cell in order to prevent a decrease in luminance.

In this case, the bus electrode may be formed of a stacked structure of a black electrode and a white electrode to improve the contrast of the screen. The black electrode is positioned on the front substrate side, one surface of which is in contact with the transparent electrode and the substrate, and the white electrode is formed on one surface of the black electrode facing the rear substrate to reflect visible light emitted toward the white electrode.

However, the bus electrode having such a structure has a small area occupied by the black electrode, which causes a problem that it is difficult to expect excellent contrast.

In addition, a conventional white electrode is formed of silver (Ag) having excellent electrical conductivity, which causes an ion-exchange reaction with the dielectric layer to cause a yellowing phenomenon of changing the dielectric layer to yellow. That is, a plasma display panel having such a white electrode has a problem in that color purity and color reproducibility are lowered, thereby degrading display quality.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to provide a plasma display panel which can improve display quality by improving the shape of a bus electrode.

In order to achieve the above object, the present invention,

A first substrate and a second substrate disposed to face each other, a partition wall disposed between both substrates to partition the discharge cells, a phosphor layer formed in the discharge cell, and an address formed along the first direction in the first substrate An electrode, a first electrode and a second electrode formed in parallel with each other along a second direction crossing the first direction on the second substrate, and a dielectric layer formed on the second substrate while covering the first electrode and the second electrode; Wherein the first electrode and the second electrode each include a bus electrode formed at an edge of the discharge cell, wherein the bus electrode includes a black layer and a white layer, and the black layer has a larger area than the white layer. Provide a panel.

The black layer is formed on the dielectric layer and may form a groove along a length direction on one surface facing the first substrate.

The white layer may be formed in the groove of the black layer.

A passivation layer may be further formed on the dielectric layer, and the passivation layer may be formed of MgO.

The partition wall is formed to extend in the first direction, and the first partition members are disposed in parallel with each other while maintaining a predetermined interval along the second direction, and the length is extended along the second direction between the first partition members. The second barrier ribs may include second barrier rib members formed in parallel with each other while maintaining a predetermined distance along the first direction.

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

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, and FIG. 3 is a front substrate of the plasma display panel shown in FIG. 1. A partial enlarged plan view of the.

Referring to the drawings, the plasma display panel is disposed to face each other at predetermined intervals (hereinafter, referred to as a "back substrate") 2 and a second substrate (hereinafter referred to as "front surface"). 4 "and a partition 6 provided between the substrates. The partition wall 6 is formed at a predetermined height between the rear substrate 2 and the front substrate 4 to partition the plurality of discharge cells 8. The discharge cells 8 are filled with a discharge gas (for example, a mixed gas containing neon (Ne) and xenon (Xe)) so as to generate vacuum ultraviolet rays by gas discharge. The phosphor layer 10 which emits light is provided.

The plasma display panel includes an address electrode 12 and a first electrode (hereinafter referred to as a “holding electrode”) corresponding to each discharge cell 8 between the rear substrate 2 and the front substrate 4 in order to realize an image by gas discharge. 14 and a second electrode (hereinafter referred to as "scan electrode") 16 are provided.

As an example, the address electrode 12 is formed along the first direction (y-axis direction in the drawing) on the inner surface of the back substrate 2 to form discharge cells 8 adjacent to the y-axis direction. Respond continuously. In addition, the plurality of address electrodes 12 are arranged side by side to correspond to the discharge cells 8 adjacent to each other in a second direction (the x-axis direction of the drawing) crossing the y-axis direction.

The address electrodes 12 are covered with the first dielectric layer 18 covering the inner surface of the back substrate 2 as described above. The first dielectric layer 18 prevents cations or electrons from directly colliding with the address electrode 12 during discharge, thereby preventing damage to the address electrode 12, and also forms and accumulates wall charges. The address electrode 12 may be formed of an opaque electrode disposed on the rear substrate 2 so as not to prevent visible light from being irradiated forward. That is, the address electrode 12 may be formed of a metal electrode having excellent conductance.

The partition wall 6 is provided on the first dielectric layer 18 to partition the discharge cells 8. The partition wall 6 includes first partition wall members 6a extending in the y-axis direction and second partition wall members 6b extending in the x-axis direction between the first partition wall members 6a. Thus, the discharge cells 8 are formed in a matrix structure.

The partition wall 6 may be formed of the first partition wall members 6a extending in the y-axis direction to form the discharge cells 8 in a stripe structure (not shown). (8) forms a structure which is opened along the y-axis direction.

In FIG. 1, the partition wall 6 forming the discharge cells 8 in a matrix structure is illustrated. In this state, when the second partition wall members 6b are removed, the first partition wall members 6a discharge the stripe structure. The cell is formed.

The phosphor layer 10 formed in each of the discharge cells 8 is coated with a phosphor paste on the side of the partition 6 and the surface of the first dielectric layer 18 located between the partitions 6 and dried. And by firing.

The phosphor layer 10 is formed of phosphors of the same color in the discharge cells 8 formed along the y-axis direction. In addition, the phosphor layer 10 is repeatedly formed by the phosphors of red (R), green (G), and blue (B) in the discharge cells 8 repeatedly arranged along the x-axis direction.

Meanwhile, referring to FIG. 3, the sustain electrode 14 and the scan electrode 16 are provided on the inner surface of the front substrate 4 so as to cause gas discharge in the discharge cells 8. Correspondingly, the surface discharge structure is formed. The sustain electrode 14 and the scan electrode 16 extend in the x-axis direction crossing the address electrode 12.

Each of the sustain electrode 14 and the scan electrode 16 includes transparent electrodes 141 and 161 for generating a discharge and bus electrodes 142 and 162 for applying a voltage signal to the transparent electrodes 141 and 161, respectively. The transparent electrodes 141 and 161 are surface discharges in the discharge cell 8, and are formed of a transparent material (eg, indium tin oxide) to secure the aperture ratio of the discharge cell 8. The bus electrodes 142 and 162 are formed of a metal material having excellent electrical conductivity to compensate for the high electrical resistance of the transparent electrodes 141 and 161.

The transparent electrodes 141 and 161 form a surface discharge structure with each other having a constant width W14 and W16 from the outer edge of the discharge cell 8 along the y-axis direction, and at the center of each discharge cell 8. The discharge gap G is formed. The bus electrodes 142 and 162 are disposed on the transparent electrodes 141 and 161, respectively, and extend in the x-axis direction at the outside of the discharge cell 8. Therefore, when a voltage signal is applied to the bus electrodes 142 and 162, a voltage signal is applied to each of the transparent electrodes 141 and 161 connected to the bus electrodes 142 and 162.

In addition, the transparent electrodes 141 and 161 may be connected together in the x-axis direction to cause discharge in each of the discharge cells 8 (not shown).

Referring back to FIGS. 1 and 2, the sustain electrode 14 and the scan electrode 16 correspond to the discharge cells 8 while crossing the address electrodes 12 and face each other, and the second dielectric layer 20 faces each other. Covered with) The second dielectric layer 20 forms and accumulates wall charges during discharge while protecting the sustain electrode 14 and the scan electrode 16 from gas discharge.

The second dielectric layer 20 is covered with the protective film 22. For example, the passivation layer 22 is formed of transparent MgO that protects the second dielectric layer 20 to increase the secondary electron emission coefficient upon discharge.

In driving the plasma display panel having the above-described structure, reset discharge is caused by a reset pulse applied to the scan electrode 16 in the reset period, and scan pulses and addresses applied to the scan electrode 16 in the addressing period following the reset period. The address discharge is caused by the address pulse applied to the electrode 12, and then the sustain discharge is caused by the sustain pulse applied to the sustain electrode 14 and the scan electrode 16 in the sustain period.

The sustain electrode 14 and the scan electrode 16 serve as electrodes for applying sustain pulses required for sustain discharge, and the scan electrodes 16 serve as electrodes for applying reset pulses and scan pulses, and the address electrodes ( 12 serves as an electrode for applying an address pulse. The sustain electrode 14, the scan electrode 16, and the address electrode 12 may have different roles depending on voltage waveforms applied to the sustain electrode 14, the scan electrode 16, and the address electrode 12, respectively, and are not necessarily limited to these roles.

The plasma display panel selects the discharge cells 8 to be turned on by the address discharge due to the interaction between the address electrode 12 and the scan electrode 16, and the interaction between the sustain electrode 14 and the scan electrode 16. The selected discharge cell 8 is driven by sustain discharge to realize an image.

In the above-described configuration, the bus electrodes 142 and 162 of the present embodiment are inserted into the grooves 24 and the black layers 142a and 162a forming the grooves 24 in the longitudinal direction on one surface facing the rear substrate 2. White layers 142b and 162b are included.

The black layers 142a and 162a are formed on one surface of the front substrate 4 and the transparent electrodes 141 and 161 facing the rear substrate 2 in a black color so as to absorb external light and improve the contrast of the screen. 24 has a constant width and is formed on one surface of the black layer along the longitudinal direction of the black layers 142a and 162a. In addition, the white layers 142b and 162b corresponding to the grooves 24 are formed in a white color having excellent conductivity.

The bus electrodes 142 and 162 having such a structure print and dry a black conductive film to form the black layers 142b and 162b having the grooves 24 described above, and print and dry the white conductive film in the grooves 24. White layers 142b and 162b may be formed, and then exposed, developed, and baked.

The bus electrodes 142 and 162 according to the present exemplary embodiment may enlarge the area of the black layers 142a and 162a formed in the black color to improve the black ratio, thereby improving the contrast of the screen. In this case, the white layers 142b and 162b formed with the color of the white system reflect the visible light emitted toward the white layers 142b and 162b to increase the brightness of the screen.

In addition, the bus electrodes 142 and 162 according to the present embodiment reduce the area of the white layers 142b and 162b facing the second dielectric layer 20, thereby reacting with the white layers 142b and 162b and the first dielectric layer 18. The effect of improving the display quality by suppressing the yellowing shape and increasing the color purity and color reproducibility of the screen is realized accordingly.

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 range of.

As described above, the plasma display panel according to the present invention increases the contrast and brightness of the screen by increasing the area of the black layer with respect to the white layer in the bus electrode, and also suppresses yellowing by forming a white layer in the groove of the black layer. Has the effect of improving.

Claims (6)

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 in the discharge cell; An address electrode formed along the first direction in the first substrate; First and second electrodes formed parallel to each other along a second direction crossing the first direction on the second substrate; A dielectric layer formed on the second substrate while covering the first electrode and the second electrode, The first electrode and the second electrode each includes a bus electrode formed on the edge of the discharge cell, The bus electrode includes a black layer and a white layer, And the black layer has a larger area than the white layer. The method of claim 1, And the black layer is formed on the dielectric layer and forms grooves along a length direction on one surface facing the first substrate. The method of claim 1, And the white layer is formed in the groove of the black layer. The method of claim 1, And a protective film formed on the dielectric layer. The method of claim 3, And a protective film formed of MgO. The method of claim 1, The bulkhead, First barrier members formed to extend in the first direction and disposed in parallel with each other while maintaining a predetermined interval in the second direction; And And second partition walls formed between the first partition members in the second direction, the second partition members being disposed parallel to each other while maintaining a predetermined distance along the first direction.

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