KR20050079427A - Plasma display panel - Google Patents

Abstract

The present invention relates to a plasma display panel in which an intermediate electrode is disposed between discharge sustaining electrodes to maximize the gap between the discharge sustaining electrodes within the allowable range in which sustain discharge occurs, thereby improving luminous efficiency.

A plasma display panel according to the present invention includes: a first substrate and a second substrate disposed to face each other; Address electrodes formed on the second substrate; A partition wall disposed between the first substrate and the second substrate and partitioning a plurality of discharge cells; A phosphor layer formed in each of the discharge cells; First and second electrodes corresponding to each discharge cell while extending in a direction crossing the address electrode on the first substrate; And a third electrode disposed between the first electrode and the second electrode so as to correspond to each of the discharge cells, the third electrode being formed to extend in a direction crossing the address electrode, and having a width of the first electrode or the second electrode. The ratio of the width of the third electrode to the ratio of 1 or less.

Description

Plasma Display Panel {PLASMA DISPLAY PANEL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, a pair of discharge sustaining electrodes arranged to correspond to respective discharge cells between both substrates to cause display discharge, and an intermediate electrode formed therebetween are formed on one substrate. The present invention relates to a plasma display panel having an electrode structure for increasing a gap between discharge sustaining electrodes.

In general, a plasma display panel is used to display an image using a gas discharge phenomenon, and is excellent in various display capacities such as display capacity, brightness, contrast, afterimage, viewing angle, etc., and has been spotlighted as a device that can replace CRT. . In the plasma display panel, a gas discharge is generated between the electrodes by a direct current or an alternating voltage applied to the electrodes, and the phosphors are excited by emission of ultraviolet rays, thereby emitting light.

FIG. 10 is a schematic exploded perspective view of a typical AC plasma display panel.

Referring to the drawings, a common electrode (X electrode) 103 and a scanning electrode (Y electrode) 105 corresponding to the discharge sustaining electrode are formed on the inner surface of the front substrate 101, and the inner surface of the back substrate 107 is formed. The address electrode 109 is formed on the surface. The discharge sustaining electrodes 103 and 105 form a pair of the common electrode 103 and the scan electrode 1105, and sustain discharge during operation between the pair of common electrode 103 and the scan electrode 105. This happens. The common electrode 103, the scan electrode 105, and the address electrode 109 are formed in a stripe shape on the inner surfaces of the front substrate 101 and the back substrate 107, respectively, and the front substrate 101 and the rear substrate ( When 107 are assembled together, they cross at right angles to each other.

On the inner surface of the front substrate 101, a dielectric layer 111 and a protective film 113 are sequentially stacked. Meanwhile, a partition wall 117 is formed on the top surface of the dielectric layer 115 on the back substrate 107, and the discharge cell 119 is formed by the partition wall 117. The discharge cell 119 is filled with an inert gas such as neon (Ne) and xenon (Xe). In addition, the phosphor 121 is coated on a predetermined portion inside the partition wall 117 that forms each discharge cell 119. The common electrode 1030 and the scan electrode 105 are composed of transparent electrodes 103a and 105a and bus electrodes 103b and 105b, respectively.

11 is a cross-sectional view of a part of the plasma display panel shown in FIG. 10.

Referring to this figure, the operation of the plasma display panel will be described schematically. First, when an address voltage and a scan voltage are applied to each of the address electrode 109 and the scan electrode 105, an address discharge occurs between the discharge cells ( Wall charges are formed in 119). Next, when a discharge sustain voltage is applied between the scan electrode 105 and the common electrode 103, the discharge discharge voltage is added to the wall voltage formed by the wall charge and the discharge discharge voltage is maintained within the discharge cell 119 when the discharge start voltage is exceeded. This will happen. In this sustain discharge state, light in the ultraviolet region of the discharge light collides with the phosphor 121 to emit visible light. Accordingly, each pixel formed for each discharge cell 119 can implement an image.

Therefore, the gap between the discharge sustain electrodes 103 and 105 in the discharge cell 119 is formed as long as possible within the range in which sustain discharge is generated, thereby emitting visible light in all the phosphor layers 121 in the discharge cell 119. It is preferable. However, the plasma display panel having the arrangement of the discharge sustaining electrodes 103 and 105 is configured to close the gap between the discharge sustaining electrodes 103 and 105 more than necessary, so it is difficult to maximize the light emission efficiency by maintaining the short gap. I have a problem.

The present invention has been made to solve the problems described above, the object of which is to arrange the intermediate electrode between the discharge sustaining electrode to increase the gap between the discharge sustaining electrode to the maximum within the allowable range where the sustain discharge occurs, luminous efficiency It is to provide a plasma display panel that improves.

In order to achieve the above object, the plasma display panel according to the present invention,

A first substrate and a second substrate disposed to face each other;

Address electrodes formed on the second substrate;

A partition wall disposed between the first substrate and the second substrate and partitioning a plurality of discharge cells;

A phosphor layer formed in each of the discharge cells;

First and second electrodes corresponding to each discharge cell while extending in a direction crossing the address electrode on the first substrate; And

A third electrode disposed between the first electrode and the second electrode to correspond to each of the discharge cells and formed to extend in a direction crossing the address electrode;

The ratio of the width of the third electrode to the width of the first electrode or the second electrode is 1 or less.

Preferably, the gap between the first electrode and the third electrode and the gap between the second electrode and the third electrode are the same.

The gap between the first electrode and the third electrode and the gap between the second electrode and the third electrode may be different from each other.

Each of the first electrode, the second electrode, and the third electrode is made of a combination of a transparent electrode and a bus electrode,

The ratio of the width of the transparent electrode of the third electrode to the width of the transparent electrode of the first electrode or the second electrode is preferably 1 or less.

The width of the third electrode is preferably formed to fall within the range of 120 to 205㎛.

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

1 is a partial plan view schematically illustrating a plasma display panel according to the present invention, and FIG. 2 is a cross-sectional view taken along the line A-A of FIG. 1.

Referring to the drawings, the plasma display panel according to the present embodiment (hereinafter referred to as 'PDP') includes a first substrate 1 and a second substrate 3 which are disposed to face each other at a predetermined interval. A plurality of address electrodes 5 are formed on the second substrate 3 along one direction (x-axis direction in the drawing) of the second substrate 3, and are orthogonal to the address electrodes 5 on the first substrate 1. The surface discharge electrodes including the first electrode 7, the second electrode 9, and the third electrode 21 are formed along the direction (y-axis direction in the drawing).

Since the first electrode 7 and the second electrode 9 correspond to each discharge cell 11 and are involved in sustain discharge, they are collectively referred to as a discharge sustaining electrode, and extend in a direction crossing the address electrode 5. .

In the present embodiment, the first electrode 7 and the second electrode 9 mainly serve as electrodes for applying a voltage necessary for sustain discharge, while the third electrode 21 mainly uses a reset waveform and a scan pulse. (scan pulse) It serves as an electrode to apply voltage. However, the role of the surface discharge electrodes including the first electrode 7, the second electrode 9, and the third electrode 21 may vary depending on the voltage waveform applied to each electrode. It is not limited.

Hereinafter, the first electrode 7 is referred to as the X electrode, the second electrode 9 is referred to as the Y electrode, and the third electrode 21 is referred to as the M electrode as the intermediate electrode.

The dielectric layer 13 and the passivation layer 15 are sequentially formed on the first substrate 1 while covering the X electrode 7 and the Y electrode 9, and the address electrode 5 is formed on the second substrate 3. A dielectric layer 17 is formed while covering.

A plurality of barrier ribs 19 are formed in the space between the first substrate 1 and the second substrate 3, and the barrier ribs 19 are disposed between the address electrodes 5 adjacent to each other, and the address electrodes ( It is formed along the direction parallel to 5) to partition the discharge cell 11 required for the plasma discharge. In addition, the partitions 19 are not limited to the stripe shape, and the discharge cells 19 may be formed in a grid shape in which each discharge cell is independently partitioned.

On the other hand, each of the X electrode 7 and the Y electrode 9 constituting the discharge sustaining electrodes 7 and 9 is composed of transparent electrodes 7a and 9a and bus electrodes 7b and 9b. Here, the transparent electrodes 7a and 9a play a role of causing surface discharge in the discharge cell 11, and a transparent material is used to secure the aperture ratio. An indium tin oxide (ITO) electrode may be used, and a bus electrode ( 7b and 9b are used to compensate for the high resistance of the transparent electrodes 7a and 9a to secure electrical conduction. Preferably, metal electrodes are used. At this time, the pair of bus electrodes 7b and 9b corresponding to each of the discharge cells 11 are formed in parallel with each other in a straight line, and the transparent electrodes 7a and 9a are discharge cells (B) from the bus electrodes 7b and 9b. It extends toward the center of 11). The shapes of the transparent electrodes 7a and 9a may be formed in parallel stripe shapes along the bus electrodes 7b and 9b. In another example, the transparent electrodes 7a and 9a may be formed to protrude to each discharge cell 11.

On the other hand, the M electrode 21 also includes the transparent electrode 21a and the bus electrode 21b, similarly to the X electrode 7 and the Y electrode 9 described above. The transparent electrode 21a plays a role of causing surface discharge in the discharge cell 11, and a transparent material is used to secure the aperture ratio. For example, an indium tin oxide (ITO) electrode may be used. The bus electrode 21b compensates for the high resistance of the transparent electrode and secures electrical conduction. It is preferable to use a metal electrode. At this time, the bus electrodes 21b corresponding to the discharge cells 11 are formed in parallel with each other in a straight line, and the transparent electrodes 21a are formed in parallel with the bus electrodes 21b.

Compared with the conventional three-electrode surface discharge electrode structure, the M electrode 21 increases the discharge path between the X electrode 7 and the Y electrode 9, which are discharge sustaining electrodes, thereby increasing the inside of the discharge cell 11. This causes gas discharge over a wider area.

FIG. 3 is a graph schematically showing waveforms of voltages applied to the electrodes of the plasma display panel shown in FIG. 1. In each graph, the horizontal axis represents time intervals and the vertical axis represents voltage levels.

At this time, the sustain discharge voltage waveform is mainly applied to the X electrode 7 and the Y electrode 9, and the reset waveform and the scan pulse voltage are applied to the M electrode 21.

According to the applied voltage waveform of the M electrode 21, each subfield is composed of a reset section T1, a scan section T2, and a sustain discharge section T3.

The reset section T1 includes an erase section I, a rising waveform section II of the intermediate electrode 21 and a falling waveform section III of the intermediate electrode.

(1-1) erasure interval (I)

This section serves to erase wall charges formed in the previous sustain discharge section T3. When the sustain discharge voltage pulse is applied to the X electrode 7 at the end of the sustain discharge section T3, and a voltage lower than the voltage applied to the X electrode 7 is applied to the Y electrode 9, the Y electrode 9 is applied. ) And the address electrode 5 are formed with positive wall charges, and the X electrode 7 and the M electrode 21 are formed with negative wall charges.

In the erase period (I), when the Y electrode 9 is biased to the voltage Vyc, when a waveform of gently falling from the Vmc voltage to the ground voltage is applied to the M electrode 21, the wall charges formed during the sustain discharge period T3 are discharged. Erased.

(1-2) M electrode rising wave section (II)

During this period, when the X electrode 7 and the Y electrode 9 are biased to the ground voltage, a gentle rising waveform from the voltage Vmd to Vset is applied to the M electrode 21 while the rising waveform is applied. In all the discharge cells 11, weak reset discharge occurs from the M electrode 21 to the address electrode 5, the X electrode 7 and the Y electrode 9, respectively. As a result, negative wall charges are accumulated on the M electrode 21, and positive wall charges are accumulated on the address electrode 5, the X electrode 7, and the Y electrode 9 at the same time.

(1-3) M electrode falling waveform section (III)

Subsequently, in the second half of the reset period T1, the waveforms of the M electrodes 21 are gently lowered from the voltage Vme toward the ground voltage while the X electrode 7 and the Y electrode 9 are biased at Vxe and Vye, respectively. When is applied, weak reset discharge occurs in all the discharge cells 11 again during this period.

At this time, since the falling waveform section III of the M electrode 21 is for slowly decreasing the wall charges accumulated by the rising waveform section II of the M electrode 21, the longer the time of the falling waveform is taken (that is, the slope is decreased). It is advantageous for address discharge because the amount of reduced wall charge can be precisely controlled.

As a falling waveform is applied to the M electrode 21, wall charges accumulated on each electrode of all the discharge cells 11 are uniformly erased, and positive wall charges are accumulated on the address electrode 5, and at the same time, X Negative wall charges are accumulated in the electrode 7, the Y electrode 9, and the M electrode 21.

(2) Scan section (T2)

 In the scan section T2, while a plurality of M electrodes 21 are biased to the Vsc voltage, scan pulses (eg, ground voltages) are sequentially applied to the M electrodes 21 to apply scan pulses, and at the same time, address electrodes ( 5, an address voltage is applied to the discharge cell 11 (that is, the discharge cell to be turned on) to be discharged. At this time, the X electrode 7 is maintained at the ground voltage, and the Y electrode 9 is applied with the voltage Vye. (I.e., apply a voltage higher than the voltage of the X electrode to the Y electrode.)

Then, discharge occurs between the M electrode 21 and the address electrode 5, and the discharge extends to the X electrode 7 and the Y electrode 9, and as a result, the X electrode 7 and the M electrode 21. Positive charges accumulate in the negative electrode, and negative wall charges accumulate in the Y electrode 9 and the address electrode 5.

(3) Maintenance discharge section (T3)

According to the sustain discharge section T3, sustain discharge voltage pulses are alternately applied to the X electrode 7 and the Y electrode 9 while the M electrode 21 is biased at the sustain discharge voltage Vm. The sustain discharge occurs in the selected discharge cell 11 in the scan section T2 through the application of such a voltage.

As described above, when the sustain discharge occurs between the X electrode 7 and the Y electrode 9, the longer the discharge path in the discharge cell 11 can effectively utilize the entire discharge space, thus, the X electrode 7 and the Y electrode The distance between the electrodes 9 is advantageous in terms of discharge efficiency. Since the M electrode 21 is disposed between the X electrode 7 and the Y electrode 9, the gap G between the M electrode 21 and the respective X electrode 7 and the Y electrode 9 is fixed. By keeping the width of the M electrode 21 wider, the distance L between the X electrode 7 and the Y electrode 9 can be extended.

As the distance L between the X electrode 7 and the Y electrode 9 involved in the sustain discharge becomes far, the path for discharging becomes longer, thereby making efficient use of the discharge space, and consequently, the luminous efficiency can be increased. However, as the distance L between the X electrode 7 and the Y electrode 9 increases, the driving voltage also increases, and thus, it is necessary to limit the voltage within a voltage range in which normal PDP driving is possible. In general, when the driving voltage, that is, the discharge start voltage exceeds 250V, the efficiency is improved even if the efficiency is improved.

When the M electrode 21 acting as described above is compared with the X electrode 7 or the Y electrode 9, the M electrode with respect to the width Lx and Ly of the X electrode 7 or the Y electrode 9. It is preferable that ratio of width Lm of (21) is 1 or less. That is, the width Lm of the M electrodes 21 is preferably formed to be narrower than the widths Lx and Ly of the X and Y electrodes 7 and 9. For example, the width Lm of the M electrode 21 may be formed to be 120 to 205 μm.

In addition, the gap G formed between the X electrode 7 and the M electrode 21 is the same as the gap G formed between the Y electrode 9 and the M electrode 21 as in the present embodiment. It may be formed, but may be formed differently. In other words, even if the M electrode 21 is disposed to be biased to either the X electrode 7 or the Y electrode 9, the same effect is obtained.

FIG. 5 is a table showing a gap relationship between an electrode width and a discharge sustaining electrode. FIG. 6 is a graph showing a voltage vs. efficiency relationship according to a change in a gap between an electrode width and a discharge sustaining electrode. It is a graph showing the discharge start voltage and efficiency according to the width ratio of the width of the intermediate electrode and the width of the discharge sustaining electrode.

As in the exemplary embodiment of the present invention, the width Lm of the M electrode 21 is 124 μm, the width Lx of the X electrode 7 and the width Ly of the Y electrode 9 are 248 μm. (7) or the ratio of the width Lm of the M electrode 21 to the width Lx, Ly of the Y electrode 9 is 0.5, the width Lm of the M electrode 21 is 174 µm, and the X electrode The width Lx of (7) and the width Ly of the Y electrode 9 were 223 占 퐉 so that the width of the M electrode 21 with respect to the width Lx and Ly of the X electrode 7 or the Y electrode 9. The ratio of (Lm) is 0.78. That is, the ratio is one or less.

In addition, when the width Lm of the M electrode 21 is 120 and 170 μm, as shown in FIG. 6, it is understood that the voltage-to-efficiency au is improved compared to the conventional case in which the M electrode 21 is not provided. Can be. Furthermore, it can be seen that the efficiency a.u increases as the width Lm of the M electrode 21 increases.

Further, as the ratio of the width Lm of the M electrode 21 to the width Lx, Ly of the X electrode 7 and the Y electrode 9 approaches 1, the curve shown in FIG. As shown by (Vf) and the curve (η), it can be seen that the discharge start voltage (Vf) and the efficiency (η) increase.

When the ratio Lm / Lx, y is 1 based on 1 or less, as the ratio Lm / Lx, y increases, the discharge initiation voltage Vf increases within an allowable range, and the efficiency η is further increased. However, if the ratio (Lm / Lx, y) exceeds 1, as the ratio (Lm / Lx, y) increases, the increase in discharge start voltage (Vf) exceeds the increase in efficiency (η). .

On the other hand, it can be seen that there is a distance d between the X electrode 7 and the Y electrode 9 of each discharge cell 11, and a capacitor having a voltage V exists.

Electric field (E) When the area is A and the dielectric constant ε, the capacitance (C) is The electrical energy (E) stored in the capacitor is Therefore, luminous efficiency? Is as follows.

That is, when the width Lm of the M electrode 21 increases, the distance d between the X electrode 7 and the Y electrode 9 (indicated by L in FIG. 4) becomes large, and the electric field or capacitance is increased. Since the turn becomes smaller, the luminous efficiency is increased.

8 is a photograph of the sustain discharge image according to the simulation when the width of the intermediate electrode is 170㎛, Figure 9 is a efficiency graph when the width of the intermediate electrode is 170㎛.

Referring to this graph, it can be seen that as the width Lm of the M electrode 21 increases, the efficiency increases at ultraviolet rays 173 and 147 nm, which are involved in the light emission efficiency. The PDP uses visible light generated by the ultraviolet light emitted by the energy transition of the excited electrons to the phosphor. The ultraviolet light of the PDP uses a resonance beam of 147 nm or a continuous spectrum molecular beam of 174 nm. Larger means more light emitted.

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, according to the plasma display panel according to the present invention, a third electrode (M electrode), which is an intermediate electrode, is disposed between the first electrode (X electrode) and the second electrode (Y electrode) as the discharge sustaining electrode. By forming a width smaller than the width of the second electrode, the distance between the first and second electrodes may be maximized to induce a long gap, thereby improving discharge efficiency.

1 is a partial plan view schematically showing a plasma display panel according to the present invention.

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

FIG. 3 is a graph schematically showing waveforms of voltages applied to the electrodes of the plasma display panel shown in FIG. 1.

4 is a partial cross-sectional view of FIG. 2 for explaining the effect of the gap between the width of the electrode and the discharge sustaining electrode.

5 is a table showing a gap relationship between the width of the electrode and the discharge sustaining electrode.

FIG. 6 is a graph illustrating a voltage vs. efficiency relationship according to a change in a gap between an electrode width and a discharge sustaining electrode.

7 is a graph illustrating a comparison of discharge start voltage and efficiency according to the ratio of the width of the intermediate electrode to the width of the discharge sustaining electrode.

8 is a photograph of the sustain discharge image simulated when the width of the intermediate electrode is 170 μm.

9 is a graph of efficiency when the width of the intermediate electrode is 170 μm.

10 is an exploded perspective view schematically illustrating a general AC plasma display panel.

FIG. 11 is a cross-sectional view of a portion of the plasma display panel shown in FIG. 10.

Claims (5)

A first substrate and a second substrate disposed to face each other; Address electrodes formed on the second substrate; A partition wall disposed between the first substrate and the second substrate and partitioning a plurality of discharge cells; A phosphor layer formed in each of the discharge cells; First and second electrodes corresponding to each discharge cell while extending in a direction crossing the address electrode on the first substrate; And A third electrode disposed between the first electrode and the second electrode to correspond to each of the discharge cells and formed to extend in a direction crossing the address electrode; And a ratio of the width of the third electrode to the width of the first or second electrode is one or less. The method of claim 1, And a gap between the first electrode and the third electrode and a gap between the second electrode and the third electrode. The method of claim 1, And a gap between the first electrode and the third electrode and a gap between the second electrode and the third electrode. The method of claim 1, Each of the first electrode, the second electrode, and the third electrode is made of a combination of a transparent electrode and a bus electrode, And a ratio of the width of the transparent electrode of the third electrode to the width of the transparent electrode of the first electrode or the second electrode is 1 or less. The method of claim 1, And a width of the third electrode in a range of 120 to 205 μm.