KR100719588B1 - Plasma display panel - Google Patents

Abstract

An object of the present invention is to provide a plasma display panel in which discharge and / or luminance imbalance does not occur even when the X electrode is grounded and driven to reduce the number of circuits driving the plasma display panel. According to an embodiment of the present invention, a partition wall partitioning a plurality of discharge cells between the first and second substrates spaced apart from each other, the first substrate and the second substrate, and one surface of the first substrate corresponding to each of the discharge cells X electrodes which are formed to be long in one direction to the ground, correspond to each of the discharge cells, and correspond to the Y electrodes disposed on one surface of the first substrate while being spaced apart from the X electrodes, and corresponding to each of the discharge cells. Address electrodes formed on the second substrate in a direction crossing the X and Y electrodes, and discharge of the X electrodes Rather small to be wider configuration than the Y electrodes and an electric field generated during the discharge of the discharge cells are focused on the Y electrodes and a plasma display panel, which is distributed to the X electrodes.

Description

Plasma display panel {Plasma display panel}

FIG. 1 is a diagram illustrating a luminance profile generally shown in an electrode of a plasma display panel having a grounded X electrode portion.

2 is an exploded perspective view illustrating a plasma display panel according to an exemplary embodiment of the present invention.

3 is a partial plan view showing a plasma display panel according to an exemplary embodiment of the present invention.

4 is a diagram illustrating a chassis side of a plasma display panel according to an exemplary embodiment of the present invention.

5 is a block diagram schematically illustrating an apparatus for driving a plasma display panel according to an exemplary embodiment of the present invention.

6 is a timing diagram illustrating a driving signal of a plasma display panel according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: Front panel 11: Front board

20: rear panel 21: rear substrate

22: address electrode 24: partition wall

25 phosphor layer 30 X electrode

30a: X transparent electrode 30b: X bus electrode

40: Y electrode 40a: Y transparent electrode

40b: Y bus electrode 50: discharge sustaining electrode pair

60: discharge cell

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel that implements an image by using gas discharge. More particularly, the present invention relates to a plasma display panel in which the luminance is unbalanced even when the X electrode is made larger than the Y electrode and driven while the X electrode is grounded. It is about.

The plasma display device refers to a flat panel display device that realizes an image by using a gas discharge phenomenon. The plasma display device has not only excellent characteristics of a large screen, high definition, ultra-thin, light weight, and wide viewing angle, but also a simpler and larger manufacturing method than other flat panel display devices. Its ease of use has attracted much attention as a large flat panel display device.

The plasma display apparatus includes a plasma display panel (PDP) for displaying an image such as an image by emitting phosphors by ultraviolet rays generated during gas discharge. The plasma display panel is classified into a direct current type, an alternating current type, and a hybrid type according to an applied discharge voltage, and an opposed discharge type and a surface discharge type according to a discharge structure. surface discharge type).

The counter discharge type has a problem of shortening the lifetime due to phosphor deterioration due to the ions emitted during discharge, while the surface discharge type overcomes the problem of the counter structure by minimizing the deterioration of the phosphor by collecting discharge to the opposite side of the phosphor. It is used as PDP structure of.

In the structure of a general plasma display panel, a partition wall is disposed between a front substrate and a rear substrate to partition a plurality of discharge cells. A plurality of sustain electrodes are printed on the bottom surface of the front substrate. The sustain electrodes form electrode pairs of the X electrodes and the Y electrodes. Each of the X and Y electrodes is composed of a transparent electrode such as indium-tin oxide (hereinafter referred to as ITO) and a bus electrode made of a conductive metal attached to one side of the transparent electrode. The sustain electrode is covered with a dielectric layer. A protective film made of a material such as magnesium oxide (MgO) is formed on the lower surface of the dielectric layer.

On the other hand, a plurality of address electrodes are printed on the upper surface of the rear substrate and extending in a direction orthogonal to the sustain electrodes while crossing the respective discharge cells. A dielectric layer is formed on the upper surface of the address electrode.

In addition, phosphors are coated on the inner surface of the partition wall and the upper surface of the lower plate dielectric layer. The discharge cell space is filled with an inert gas such as Xe or Ar.

When discharge occurs at the sustain electrode, electrons collide with the gas to cause ionization, excitation, and radiation, and the ultraviolet rays generated at this time hit the phosphor to generate visible light, thereby realizing an image.

In order to drive the plasma display panel (hereinafter also referred to as PDP) as described above, circuits for controlling the voltage applied to each electrode are required. These circuits, however, are expensive and represent a significant portion of the overall PDP price. Therefore, reducing the number of PDP driving circuits is the most effective way to lower the PDP supply price.

As one such method, a PDP without a circuit for driving the X electrode can be considered. At this time, the X electrode portion is grounded to maintain a constant ground voltage at all times. There is a continuous study on the driving method of such a PDP.

On the other hand, in the case of grounding the X electrode and driving the PDP as described above, since the voltage fluctuations exist only in the Y electrode, an electric field is concentrated on the Y electrode, resulting in an unbalance in luminance between the X and Y electrodes. In addition, such an imbalance may cause damage to the surface of the MgO protective film.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the luminance profile at the time of performing discharge in the state which grounded X electrode. Since the ground voltage is maintained at the X electrode when the voltage for sustain discharge is applied to the Y electrode, the discharge is actively generated near the Y electrode where the electric field is relatively concentrated. This results in a nonuniformity in brightness, and as a result, the brightness of the Y electrode portion appears higher than the brightness of the X electrode portion as shown, which is a problem.

An object of the present invention is to reduce the number of circuits for driving a plasma display panel.

It is also an object of the present invention to provide a plasma display panel in which discharge and / or luminance imbalance does not occur even when the X electrode is grounded and driven.

According to the present invention, a partition wall partitioning a plurality of discharge cells between the first and second substrates spaced apart from each other, the first substrate and the second substrate, and corresponding to each of the discharge cells is provided on one surface of the first substrate. X electrodes which are formed to be long in one direction and are grounded, Y electrodes disposed on one surface of the first substrate while being spaced from the X electrodes while corresponding to the respective discharge cells, and corresponding to each of the discharge cells. The second substrate includes address electrodes formed in a direction crossing the X and Y electrodes, and the discharge area of the X electrodes is configured to be wider than that of the Y electrodes so that the electric field generated when the discharge cells are discharged is Provided is a plasma display panel which is not concentrated only on Y electrodes and is dispersed to the X electrodes.

Here, the discharge area difference between the X and Y electrodes may be caused by forming the transparent electrode of the X electrode wider than the transparent electrode of the Y electrode.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 to 3 are views showing the structure of the plasma display panel according to an embodiment of the present invention. Referring to the drawings, the plasma display panel according to the present embodiment includes a first substrate 11, a second substrate 21, sustain electrode pairs 50, address electrodes 22, a partition wall 24, and protection. A layer 15, phosphor layers 25, a first dielectric layer 14, a second dielectric layer 23, and a discharge gas (not shown) are provided.

The first substrate 11 is usually made of a material having excellent light transmittance mainly containing glass. However, the first substrate 11 may be colored in order to improve contrast by reducing the reflected luminance. In addition, the second substrate 21 is disposed to face each other at a predetermined interval from the first substrate 11, and is made of a material having excellent light transmittance such as glass. The second substrate 21 may also be colored similarly to the first substrate 11.

In the present invention, visible light generated in the red, green, and blue discharge cells 60 may be emitted to the outside through the first substrate 11 and / or the second substrate 21. However, in the present embodiment, visible light generated in the red, green, and blue discharge cells 60 is emitted to the outside through the first substrate 11.

A partition wall 24 is formed between the first substrate 11 and the second substrate 21 to partition the plurality of red, green, and blue discharge cells 60 in which a discharge phenomenon occurs. In the red, green, and blue discharge cells 60, the red, green, and blue discharge cells 60 are sequentially arranged along the direction in which the sustain electrode pairs 50 extend (the x direction in the drawing).

The partition wall 24 serves to prevent optical crosstalk between the red, green, and blue discharge cells 60. In this embodiment, the partition wall 24 is disposed in the direction in which the address electrodes 22 described later extend (y direction in the drawing).

Of course, the shape of the barrier ribs is not limited to this, and as long as it is possible to form a plurality of discharge spaces, the barrier ribs of various patterns, for example, when the cross section is rectangular, may be closed barrier ribs such as waffles, matrices, deltas and the like. Can be. In addition, the closed partition wall may be formed such that the cross section of the discharge space becomes a polygon such as a triangle, a pentagon, or a circle, an ellipse, or the like.

On the first substrate 11 facing the second substrate 21, sustain electrode pairs 50 are arranged in parallel at predetermined intervals. Each sustain electrode pair 50 includes an X electrode 30 and a Y electrode 40, and the X electrode 30 and the Y electrode 40 are plasma discharged in the red, green, and blue discharge cells 60. Causes

Each X electrode 30 includes a transparent electrode 30a and a bus electrode 30b. The Y electrode 40 also includes a transparent electrode 40a and a bus electrode 40b. The transparent electrode is preferably formed of a conductive transparent or translucent material, and may be selected as indium tin oxide (ITO) or antimony doped tin oxide (ATO). Since the transparent electrode has a large resistance, it is preferable to select a bus electrode for compensating for the metal material having good conductivity.

In the X electrode 30 and the Y electrode 40 as described above, in the present embodiment, the X transparent electrode 30a is formed larger than the Y transparent electrode 40a. FIG. 3 is a partial plan view briefly showing the arrangement of the electrodes and the partition walls so that the size difference between the X transparent electrode 30a and the Y transparent electrode 40a can be easily understood.

2 to 3, it can be seen that the X transparent electrode 30a is formed to have a wider width than the Y transparent electrode 40a. At this time, the X transparent electrode 30a is preferably about 5% larger than the Y transparent electrode 40. However, the present invention is not limited thereto and the difference in electrode size may change according to a change in design conditions.

This larger X transparent electrode compensates for the difference in luminance between the two electrodes due to the concentration of an electric field only on the Y electrode 40 when the X electrode 30 is discharged while the X electrode 30 is grounded and maintained at a constant voltage level. To do that. The application of the voltage in the state where the X electrode 30 is grounded will be described later in more detail.

Meanwhile, the first dielectric layer 14 is formed on the first substrate 11 to fill the X electrodes 30 and the Y electrodes 40. The first dielectric layer 14 is directly connected between the adjacent X electrode 30 and the Y electrode 40 during discharge, and positive or negative electrons directly collide with the X electrodes 30 and the Y electrodes 40 to discharge the X electrode. While preventing damage to the 30 and the Y electrode 40, a dielectric material capable of inducing charge and accumulating wall charges is formed. Such dielectrics include PbO, B 2 O 3, SiO 2, and the like.

On the first dielectric layer 14, a protective film 15 usually made of MgO is formed. The protective film 15 prevents cations and electrons from colliding with the first dielectric layer 14 during the discharge and damages the first dielectric layer 14, and has good light transmittance and emits a large amount of secondary electrons during the discharge. In particular, the protective film 15 is mainly formed into a thin film using sputtering, electron beam deposition, or the like.

On the second substrate 21 opposite to the first substrate 11, the address electrodes 22 are disposed to intersect the X electrodes 30 and the Y electrodes 40. The address electrodes 22 are intended to cause an address discharge to facilitate sustain discharge between the X electrodes 30 and the Y electrodes 40. More specifically, the address electrodes 22 lower the voltage for discharging the discharge. . The address discharge is a discharge occurring between the Y electrodes 40 and the address electrodes 22. When the address discharge is completed, cations are accumulated on the Y electrodes 40 and electrons are accumulated on the X electrode 30 side. As a result, the sustain discharge between the X electrodes 30 and the Y electrodes 40 becomes easier.

The second dielectric layer 23 is formed on the second substrate 21 to fill the address electrodes 22. The second dielectric layer 23 is formed as a dielectric that can induce charge while preventing cations or electrons from colliding with the address electrodes 22 upon discharge, such as PbO, B2O3, SiO2, etc.

Red, green, and blue light emitting phosphor layers 25 are formed on the second dielectric layer 23 between the partition walls 24 partitioning the discharge cells 60 and on the side surfaces of the partition walls 24. The phosphor layers 25 have a component for generating visible light by receiving ultraviolet rays. The red phosphor layers formed in the red discharge cells include phosphors such as Y (V, P) O 4: Eu, and green discharge cells. The red light emitting phosphor layers formed on the light emitting diodes include phosphors such as Zn 2 SiO 4: Mn, and the like, and the blue light emitting phosphor layers formed on the blue discharge cells include phosphors such as BAM: Eu and the like.

In addition, the discharge cells 60 are filled with a discharge gas in which neon (Ne), xenon (Xe), and the like are mixed, and in the state where the discharge gas is filled as described above, the first and second substrates 111 and 121. The first substrate and the second substrates 111 and 121 are sealed and joined to each other by a sealing member such as frit glass formed at the edge of the c).

4 is a view schematically illustrating a state in which circuits are disposed on a rear surface of the chassis. As shown, the plasma display apparatus 100 includes a Y electrode driver 110, an address electrode driver 120, a switching mode power supply 130, a logic board 140, an X electrode ground board 150, and a TCP. (tape carrier package; 160) is included.

It is important to note that in the conventional plasma display device, the driving circuit section 155 for driving the X electrode is required, but in this embodiment, the driving circuit section is not necessary because the X electrode 30 is grounded. Only a small ground board 150 for grounding the X electrode is sufficient.

The driving of the PDP will now be described with the X electrode 30 grounded. FIG. 5 is a diagram for explaining driving signals of the PDP by diagramming the circuits of FIG. 4 in blocks. 6 is a timing diagram illustrating an example of a signal level applied to each electrode unit.

Referring to FIG. 5, the apparatus for driving a plasma display panel according to the present embodiment includes an image processor 400, a logic controller 402, a Y driver 404, an address driver 406, and a plasma display panel 1. ).

The image processor 400 receives an external video signal such as a PC signal, a DVD signal, a video signal, or a TV signal from the outside, converts an analog signal into a digital signal, and processes the digital signal into an internal video signal. The internal video signals are 8-bit red (R), green (G), and blue (B) image data, clock signals, and vertical and horizontal sync signals, respectively.

The logic controller 402 receives an internal image signal from the image processor 400 and performs an gamma correction, an automatic power control (APC) step, and the like, to respectively output an address driving control signal SA and a Y driving control signal SY. Output

The Y driver 404 receives the Y drive control signal SY from the logic controller 402 and has an erase pulse having an erase voltage for initialization discharge in a reset period (PR of FIG. 6), and an address period (of FIG. 6). A positive scan high voltage (Vsch of FIG. 6) is applied to the PA, and a scan signal having a negative scan low voltage (Vscl of FIG. 6) sequentially along the vertical direction of the panel 1, and a sustain discharge period ( A sustain pulse having alternating positive sustain discharge voltage (Vs in FIG. 6) and negative sustain discharge voltage (-Vs in FIG. 6) in the PS of FIG. 6 is connected to the Y electrode lines ( Also referred to as scan electrode lines; Y1, ..., Yn). Here, the Y electrode lines represented by Y1, and Yn number the plurality of Y electrodes arranged on the panel in order. Hereinafter, the same numbers are applied to the X electrodes and the address electrodes.

The address driver 406 receives the address drive control signal SA from the logic controller 402 and has an address voltage (Va in FIG. 6) in a cell to be turned on among all cells in the address period (PA in FIG. 6). The display data signal is output to the address electrode lines of the plasma display panel 1.

On the other hand, unlike the conventional driving device, in the present invention, there is no X driving part, and thus, the ground voltage Vg is continuously applied to the X electrode lines (hereinafter referred to as sustain electrode lines; X1, ..., Xn). .

6 is a timing diagram for explaining a driving signal of the panel according to the present embodiment. Referring to the drawings, one subfield SF includes a reset period PR, an address period PA, and a sustain discharge period PS.

In the reset period PR, the ground voltage Vg is first applied to the scan electrode lines Y1, ..., Yn. Next, a sustain discharge voltage Vs, which is a first voltage, is suddenly applied, and a third ramp (highest rise) is applied by a rising ramp signal from the first voltage Vs to rise by a rising voltage Vset, which is a second voltage. Voltage; Vset + Vs). The weak discharge occurs due to the application of the rising ramp signal having an inclined slope, and the negative discharge starts to accumulate in the vicinity of the scan electrode lines Y1,..., And Yn. Next, after rapidly falling to the first voltage Vs, a falling ramp signal is applied to reach the fourth falling voltage Vnf. Unlike the conventional driving signal, the driving signal according to the present invention does not use the X driving unit which supplies the driving signal to the sustain electrode lines X1,. In order to compensate for the bias voltage applied to (X1, ..., Xn), the falling slope is more sharp than the falling slope of the conventional driving signal. As the falling ramp signal is applied, a discharge occurs, and a portion of the negative charges accumulated near the scan electrode lines Y1,..., And Yn is emitted while the discharge occurs. As a result, a negative amount of negative charge suitable for generating an address discharge remains in the vicinity of the scan electrode lines Y1, ..., and Yn. The ground voltage Vg is applied to the sustain electrode lines X1, ..., Xn and the address electrode lines A1, A2, ..., Am.

Next, in order to select a cell to be turned on in the address period PA, a scan high voltage Vsch, which is a fifth voltage, is first applied to the scan electrode lines Y1,. A scan pulse having a scan low voltage Vscl, which is a sixth voltage, is applied to each line. A display data signal having an address voltage Va, which is a seventh voltage, is applied to the address electrode lines A1, A2, ..., Am in accordance with the scan pulse. The ground voltage Vg is continuously applied to the sustain electrode lines X1,..., Xn. The address discharge is performed by the seventh voltage Va, the sixth voltage Vscl, the wall voltage caused by the negative charge near the scan electrode Y, and the wall voltage caused by the positive charge near the address electrode A. After the address discharge is performed, positive charges are accumulated near the scan electrode Y, and negative charges are accumulated near the sustain electrode X.

In the sustain discharge period PS, a sustain pulse having a positive first voltage Vs and a negative first voltage -Vs is applied to the scan electrode lines Y1, ..., Yn. The ground voltage Vg is applied to the electrode lines X1,..., Xn and the address electrode lines.

Meanwhile, an eighth voltage, which is an intermediate voltage, may be further included between the first positive voltage Vs and the first negative voltage −Vs. The eighth voltage may be a ground voltage Vg. By further having an intermediate voltage, it is possible to prevent a sudden voltage change between the first positive voltage Vs and the first negative voltage -Vs.

First, when the first positive voltage Vs is applied to the scan electrode Y, the first positive voltage Vs applied to the scan electrode Y and the ground voltage Vg of the sustain electrode X are applied. And the sustain discharge is performed due to the wall voltage due to the positive charge accumulated near the main dictionary electrode (Y) and the wall voltage due to the negative charge accumulated near the sustain electrode (X), and a negative charge is generated near the scan electrode (Y). The positive charge is accumulated near the sustain electrode (X).

Next, a negative first voltage (-Vs) is applied to the scan electrode (Y), and the ground voltage (Vg) is continuously maintained at the sustain electrode (X). The first negative voltage (-Vs) applied to the scan electrode (Y), the ground voltage (Vg) of the sustain electrode (X), the wall voltage due to the negative charge accumulated near the scan electrode (Y), and the sustain electrode ( As the sustain discharge is performed due to the wall voltage due to the positive charge accumulated in X), the positive charge is accumulated near the scan electrode Y, and the negative charge is accumulated near the sustain electrode X.

Next, the first positive voltage Vs is applied to the scan electrode Y, and the ground voltage Vg is continuously maintained at the sustain electrode X. The maintenance discharge is continued by repeating the above process.

According to the plasma display panel according to the present invention, since the number of driving circuits of the plasma display panel can be reduced, the price of the plasma display device can be reduced.

According to the present invention, even when the X electrode is grounded and driven, the discharge between electrodes and / or the unbalance of luminance can be reduced.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (5)

First and second substrates spaced apart from each other; A partition wall partitioning a plurality of discharge cells between the first substrate and the second substrate; X electrodes which are grounded to correspond to each discharge cell and extend in one direction on one surface of the first substrate; Y electrodes corresponding to each of the discharge cells and spaced apart from the X electrodes and disposed on one surface of the first substrate; And Address electrodes formed on the second substrate in a direction crossing the X and Y electrodes, corresponding to the respective discharge cells; And a discharge area of the X electrodes wider than the Y electrodes so that an electric field generated when the discharge cells are discharged is dispersed to the X electrodes instead of being concentrated only on the Y electrodes. The method of claim 1, And the X and Y electrodes each include a transparent electrode and a bus electrode. The method of claim 2, And a discharge area larger than that of the Y electrode in the transparent electrode of the X electrode for each of the discharge cells. The method of claim 1, A fluorescent layer applied to an inner wall of the discharge cell; And And an excitation gas filled in the discharge cells. The method of claim 1, And the X electrodes are connected to each other at one end.

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