KR100515359B1 - Plasma display panel - Google Patents

Abstract

The present invention relates to a plasma display panel which shortens a moving path of electrons and ions during sustain discharge, improves a discharge delay, and enables high-speed addressing at a low voltage, comprising: first and second substrates facing each other; Address electrodes formed on the first substrate and covered by a lower dielectric layer; A partition wall disposed in a space between the first substrate and the second substrate to form a discharge space; Red, green, and blue fluorescent layers formed in the discharge space; Discharge holding electrodes formed of a pair of scan electrodes and display electrodes formed on the second substrate and covered by an upper dielectric layer; A protective film formed on the surface of the upper dielectric layer, wherein the protective film has a base layer formed to have a uniform thickness on the surface of the upper dielectric layer, and a protrusion formed at an arbitrary thickness on the base layer on the scan electrode and the display electrode to protrude toward the first substrate. It provides a plasma display panel comprising.

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, to a plasma display panel which shortens a moving path of electrons and ions during sustain discharge, improves discharge delay, and enables high-speed addressing at low voltage.

In general, a plasma display panel (PDP) is a display device for realizing an image by exciting phosphors by vacuum ultraviolet rays caused by gas discharge occurring in a discharge cell. It is attracting attention as the next generation thin display device. Such PDPs are roughly classified into alternating current, direct current type, and mixed type, and AC type PDPs having a three-electrode surface discharge structure are common.

In the AC-type PDP having the three-electrode surface discharge structure, an address electrode, a partition wall, and a fluorescent layer are formed on a rear substrate corresponding to each discharge cell, and a discharge holding electrode composed of a scan electrode and a display electrode is formed on the front substrate. The address electrode and the discharge sustain electrode are covered with respective dielectric layers, and the discharge cells are filled with discharge gas (mainly Ne-Xe mixed gas).

With the above configuration, when an address voltage Va is applied between the address electrode and the scan electrode, an address discharge occurs in the discharge cell, and as a result of the address discharge, a wall over the dielectric layer on the address electrode and the dielectric layer on the scan electrode and the display electrode is formed. Wall charge is generated to select a discharge cell in which light emission will occur.

Subsequently, when the sustain voltage Vs is applied between the scan electrode and the display electrode of the selected discharge cell, the ions accumulated on the scan electrode and the electrons accumulated on the display electrode collide with each other to cause plasma discharge. Vacuum ultraviolet light is emitted from the excitation atom. The vacuum ultraviolet rays excite the fluorescent layer and convert it into visible light, thereby enabling color display.

In the PDP operating as described above, as shown in FIG. 8, the dielectric layer 3 provided on the front substrate 1 limits the plasma discharge current and accumulates wall charges during sustain discharge. The dielectric layer 3 is covered with a protective film 5, in particular an MgO protective film 5, which protects the dielectric layer 3 from sputtering generated during plasma discharge and prevents damage of the secondary electrons. It serves to increase the emission efficiency.

However, in the conventional PDP, due to the characteristics of the surface discharge structure, the discharge path is extended by forming a substantially semi-circular shape (see dotted line) between the scan electrode 7 and the display electrode 9 during sustain discharge. Have This discharge path induces a discharge delay, and the increase of the discharge area causes the emission of secondary electrons not to be smooth, which makes low voltage high speed addressing difficult.

Therefore, efforts are being made to realize high-speed addressing at low voltage by improving the protective film, among other components of the PDP, which affect the sustain discharge. Prior arts in this regard include "AC type gas discharge panels" disclosed in Japanese Patent Laid-Open Publication No. 1996-138557, "plasma display panels" disclosed in Japanese Laid-Open Patent Publication 1996-339767 and "AC disclosed in Japanese Laid-Open Patent Publication 1997-185945. Type plasma display panel and its manufacturing method ".

However, since the above-described prior arts mainly focus on the material of the protective film, it is difficult to substantially expect the effect on the shortening of the movement path of electrons and ions during sustain discharge. Accordingly, the above-described prior arts have certain limitations in improving discharge delay and at the same time realizing low voltage fast addressing.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to shorten a moving path of electrons and ions during sustain discharge, to improve discharge delay, to realize high-speed addressing of low voltage, and to improve discharge efficiency. To provide a plasma display panel that can increase the brightness of the.

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

First and second substrates opposed to each other, address electrodes formed on the first substrate and covered by a lower dielectric layer, partition walls disposed in a space between the first and second substrates to form a discharge space; A red, green, and blue fluorescent layer formed in the discharge space, a pair of scan electrodes and display electrodes formed on the second substrate, discharge sustaining electrodes covered by the upper dielectric layer, and formed on the upper dielectric layer surface. A protective film, wherein the protective film includes a base layer having a uniform thickness on the upper dielectric layer surface, and a protrusion formed at a predetermined thickness on the base layer on the scan electrode and the display electrode and protruding toward the first substrate. to provide.

The scan electrode and the display electrode include a transparent electrode formed in a stripe pattern, and a bus electrode formed along one edge of the transparent electrode. In another embodiment, the scan electrode and the display electrode include a bus electrode formed in a stripe pattern and a transparent electrode extending from the bus electrode toward the inside of each discharge cell so as to face each other.

The protrusion is formed in a stripe pattern along the discharge sustaining electrode direction. In another embodiment, the protrusions are formed independently for each discharge cell, and even in this case, the protrusions are formed in a stripe pattern along the discharge sustaining electrode direction in each discharge cell.

Preferably, the protrusion is formed to be larger than the width of the bus electrode and smaller than the width of the transparent electrode. In addition, when the space | interval between a scan electrode and a display electrode is called D1, and the space | interval between two protrusion parts located on a scan electrode and a display electrode is called D2, D1 and D2 satisfy | fill the following conditions.

D2 / D1 ≥ 1.5

Preferably, the thickness of the protrusion is made 3 to 15 times the thickness of the base layer, and more preferably 5 to 10 times the thickness of the base layer. In addition, both sides of the protrusion may be formed to be inclined. In this case, the inclination angle of the side of the protrusion relative to the normal of the second substrate is 3 ° or more, preferably 3 to 60 °.

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.

Referring to the drawings, in the plasma display panel according to the present embodiment (hereinafter referred to as 'PDP'), the first substrate 2 and the second substrate 4 are disposed to face each other at random intervals, and between the substrates. A discharge space 6 is formed in the chamber to realize an arbitrary color image with visible light emission by the discharge mechanism.

In detail, the address electrodes 8 are formed in one direction (Y direction of the drawing) on the inner surface of the first substrate 2, and cover the address electrodes 8 to cover the first substrate 2. The lower dielectric layer 10 is formed over the entire inner surface. The address electrode 8 is formed in a stripe pattern, for example, and is formed in parallel with a neighboring address electrode 8 at a predetermined interval.

On the lower dielectric layer 10, a partition 12, for example, a stripe 12 having a stripe pattern parallel to the address electrode 8, is formed, and red and green are disposed on the side surface of the partition 12 and the upper surface of the lower dielectric layer 10. Blue fluorescent layers 14R, 14G and 14B are provided. The partition wall 12 is disposed between each of the address electrodes 8 and is formed to have a height of approximately 120 μm to form a discharge space 6 between the first and second substrates 2 and 4. At this time, the shape of the partition wall 12 is not limited to the above-described stripe pattern, it can be modified into various patterns such as a grid pattern.

On the inner surface of the second substrate 4 opposite to the first substrate 2, a discharge composed of the scan electrode 16 and the display electrode 18 is arranged along a direction orthogonal to the address electrode 8 (the X direction in the drawing). The sustain electrode 20 is formed, and the upper dielectric layer 22 and the passivation layer 24 are disposed on the entire inner surface of the second substrate 4 while covering the discharge sustain electrodes 20. The thickness of the upper dielectric layer 22 is approximately 30 mu m, and the component of the protective film 24 is preferably MgO.

In this embodiment, the scan electrode 16 and the display electrode 18 are formed along the edges of one side of the transparent electrodes 16a and 18a of the stripe pattern and the transparent electrodes 16a and 18a, respectively, to form the transparent electrodes 16a and 18a. Made of metal bus electrodes 16b and 18b to prevent a voltage drop. Indium tin oxide (ITO) is preferable for the transparent electrodes 16a and 18a, and a metal material having excellent conductivity such as silver (Ag) is preferable for the bus electrodes 16b and 18b.

By the combination of the first substrate 2 and the second substrate 4 described above, the discharge space 6 in which the address electrode 8 and the discharge sustain electrode 20 intersect constitute one discharge cell, and the discharge cell The interior is filled with discharge gas (mainly Ne-Xe mixed gas).

Here, the PDP according to the present embodiment provides the shape of the protective film 24 which can shorten the movement path of electrons and ions during the sustain discharge, thereby increasing the efficiency of the sustain discharge. 2 to 4 are partial cross-sectional views of the second substrate illustrated in FIG. 1, and schematically illustrate movement paths of electrons and ions measured in the sustaining section in FIG. 4.

Referring to the drawings, the passivation layer 24 may be formed on the base layer 24a having an arbitrary thickness and uniformly formed on the surface of the upper dielectric layer 22, and on the base layer 24a on the scan electrode 16 and the display electrode 18. It is formed of a protrusion 24b formed to an arbitrary thickness and protruding toward the first substrate 2. As a result, a pair of protrusions 24b are positioned for each discharge cell, and the pair of protrusions 24b are disposed to face each other with a space between the scan electrode 16 and the display electrode 18 interposed therebetween.

The protective film 24 having the above-described configuration forms a base layer 24a by applying a protective film forming material, for example, MgO, to the surface of the upper dielectric layer 22, and then forms the base layer on the scan electrode 16 and the display electrode 18. The protective film forming material is applied on at least one of 24a to easily complete the process of forming the protrusion 24b. Below, preferable shape conditions of the base layer 24a and the protrusion part 24b which comprise the protective film 24 are demonstrated.

First, referring to the planar shape of the protrusion 24b, the protrusion 24b is formed in a stripe pattern parallel to the discharge sustaining electrode 20, as shown in FIG. Thus, in the discharge cells positioned along the direction orthogonal to the address electrode (X direction in the drawing), the pair of protrusions 24b are disposed to face each other at regular intervals.

The width of the protrusion 24b is determined in consideration of the widths of the transparent electrodes 16a and 18a and the bus electrodes 16b and 18b, and the upper dielectric layer on the transparent electrodes 16a and 18a and the bus electrodes 16b and 18b. (22) In particular, a portion where the upper dielectric layer 22 and the passivation layer 24 contact each other on the bus electrodes 16b and 18b may be a portion that is prone to damage due to a voltage load.

Therefore, it is preferable that the width of the protrusion 24b is larger than the width of the bus electrodes 16b and 18b so that the protrusion 24b fully covers the bus electrodes 16b and 18b. In addition, if the width of the protrusions 24b is larger than the widths of the transparent electrodes 16a and 18a, sufficient discharge space cannot be secured between the two protrusions 24b, so that the protrusions 24b satisfy the following conditions in consideration of this. Is formed.

W1 <W2 <W3

Here, W1 represents the width of the bus electrodes 16b and 18b, W2 represents the width of the protrusion 24b, and W3 represents the width of the transparent electrodes 16a and 18a. For example, when the widths of the transparent electrodes 16a and 18a are approximately 300 µm, the widths of the bus electrodes 16b and 18b and the protrusion 24b are preferably about 100 µm and 150 µm, respectively.

Next, the formation position of the protrusion part 24b is examined. The protrusions 24b are disposed on the scan electrode 16 and the display electrode 18 as described above, and more preferably, the space between the two protrusions 24b to ensure sufficient discharge space between the two protrusions 24b. Is set larger than the distance between the scan electrode 16 and the display electrode 18. Preferably, the protrusion 24b of the protective film 24 satisfies the following condition.

D2 / D1 ≥ 1.5

Here, D1 represents a gap between the scan electrode 16 and the display electrode 18, and D2 represents a gap between the two protrusions 24b.

As such, the distance between the two protrusions 24b positioned in one discharge cell is preferably 1.5 times or more the distance between the scan electrode 16 and the display electrode 18, which is discharged when the D2 / D1 value is smaller than 1.5. This is because sustain discharge does not occur smoothly in the cell, resulting in discharge failure, and as a result, discharge efficiency and screen brightness are reduced. For example, when the distance between the scan electrode 16 and the display electrode 18 is 100 μm, the distance between the two protrusions 24b may be about 300 μm.

Next, with reference to the thickness of the base layer 24a and the protrusion 24b of the protective film 24, the thickness t2 of the protrusion 24b is preferably 3 to 15 times the thickness t1 of the base layer 24a. . If the thickness of the protrusion 24b is less than three times the thickness of the base layer 24a, it is difficult to expect the discharge efficiency to be improved by the protrusion 24b, and the thickness of the protrusion 24b is 15 times the thickness of the base layer 24a. This is because the excess of the protective film 24 manufacturing process is delayed and the productivity is lowered.

More preferably, the thickness t2 of the protrusion 24b is in the range of 5 to 10 times the thickness t1 of the base layer 24a. As a result of the experiment of the present inventors, when the thickness of the protrusion 24b is 5 to 10 times the thickness of the base layer 24a, the process delay of the protective film 24 can be minimized while optimally ensuring the improvement of the discharge efficiency by the protrusion 24b. Can be.

In the PDP configured as described above, when an address voltage Va is applied between the address electrode 8 and the scan electrode 16, an address discharge occurs in the discharge cell, and as a result of the address discharge, the lower dielectric layer on the address electrode 8. 10 and wall charges are generated on the scan electrode 16 and the upper dielectric layer 22 on the display electrode 18 to select a discharge cell in which light emission is to occur.

Subsequently, when the sustain voltage Vs is applied between the scan electrode 16 and the display electrode 18 of the selected discharge cell, ions accumulated on the scan electrode 16 and electrons accumulated on the display electrode 18 collide with each other. Plasma discharge occurs. At this time, the PDP according to the present embodiment moves electrons and ions in a substantially straight path in the space between the side surfaces of the two protrusions 24b by the shape of the protective film 24 described above, as shown in FIG. 4, and the two protrusions In the space between the upper surfaces of 24b, they move in an approximate arc shape to cause plasma discharge.

The above-mentioned electron and ion migration paths show a shortened result compared with the conventional PDP shown in FIG. 8, which means that the protrusions 24b move the electron and ion paths from the conventional semicircle to the substantially straight or arc shape. Due to a change. Therefore, the PDP according to the present embodiment improves the discharge delay by shortening the movement path of electrons and ions in the holding section due to the shape of the protective film 24 described above, and by increasing the surface area of the protective film 24 by the protrusion 24b. The emission area of the secondary electrons is enlarged, so that the discharge efficiency is increased.

In addition, vacuum ultraviolet rays are emitted from the excitation atoms of Xe generated during plasma discharge, and the vacuum ultraviolet rays excite the fluorescent layer of the corresponding discharge cells and convert them into visible light, thereby enabling color display. At this time, as the discharge efficiency is improved, the PDP according to the present embodiment emits vacuum ultraviolet rays and visible light of stronger intensity, increases the brightness of the screen, and lowers the driving voltage, thereby enabling high-speed addressing of low voltage.

Meanwhile, the above-described passivation layer 24 has an average thickness increased by the protrusions 24b. The increase in the thickness of the passivation layer 24 suppresses damage of the upper dielectric layer 22 and the passivation layer 24 due to the discharge current. Do it. Therefore, the upper dielectric layer 22 has a dielectric constant of 10 to 20, preferably 14 to 16, which is higher than that of the conventional upper dielectric layer. As a result, the charge charging effect of the upper dielectric layer 22 is improved, and wall charges are more easily accumulated. Improve the discharge efficiency.

Next, modifications to the embodiment of the present invention will be described with reference to FIGS. 5 to 7.

FIG. 5 is a first modification, in which case the transparent electrodes 16a, 18a extend from the bus electrodes 16b, 18b into the respective discharge cells 26R, 26G, 26B, based on the structure of the above-described embodiment. It is made of a protrusion that is formed so that the pair is facing. In this modification in which the transparent electrodes 16a and 18a are formed in the protruding structure as described above, erroneous discharge between discharge cells positioned along the bus electrodes 16b and 18b directions can be suppressed. At this time, the protruding portion 24b of the protective film has a stripe pattern parallel to the bus electrodes 16b and 18b as in the above-described embodiment.

FIG. 6 is a second modification, in which case the projection 24b of the protective film is independent for each discharge cell 26R, 26G, 26B corresponding to the transparent electrodes 16a, 18a, based on the structure of the first modification described above. It is made of an island (island) that is provided as. In the present modification, the width W4 of the protrusion 24b in the bus electrode 16b and 18b directions is the same as the width W5 of the transparent electrodes 16a and 18a in the bus electrode 16b and 18b directions. Can be.

FIG. 7 is a third modified example. In this case, both sides of the protrusion 24b are inclined to form the PDP, based on the structure of the above-described embodiments and modified examples. That is, in the present modification, the protrusion 24b has a shape in which its width gradually narrows from the lower surface in contact with the base layer 24a to the upper surface facing the first substrate.

A boundary point between the base layer 24a and the protrusion 24b of the passivation layer 24 may be a portion in which a voltage load is generated due to a current flow between the scan electrode 16 and the display electrode 18, and thus may be easily damaged. . Accordingly, in the present modified example in which both side surfaces of the protrusion 24b are formed as the inclined surface, the structural strength at the boundary point between the base layer 24a and the protrusion 24b is reinforced to prevent damage due to voltage load, and the protective film 24 You can make this work reliably.

In addition, in the present modified example, as both side surfaces of the protrusion 24b are formed to be inclined, the surface area of the protective film 24 is increased to increase the emission area of the secondary electrons.

Preferably, the inclination angle θ of the side surface of the protruding portion 24b with respect to the normal line (see dotted line display) of the second substrate 4 is 3 ° or more, preferably in the range of 3 to 60 °. This is because when the inclination angle θ of the side surface of the protrusion 24b with respect to the normal is less than 3 °, it is difficult to prevent damage of the protective film 24 and the protective film 24 is difficult to stably function. This is because when the inclination angle θ of the side surface of the protruding portion 24b exceeds 60 °, difficulty in processing increases.

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, according to the present invention, the moving distance between the electrons and the ions in the holding section is shortened by the above-described protective film shape to improve the discharge delay. In addition, due to an increase in the discharge area between the scan electrode and the display electrode, secondary electron emission is increased to increase discharge efficiency. Accordingly, the plasma display panel according to the present invention enables high-speed addressing of low voltage, and increases luminance of a screen as it emits stronger ultraviolet light and visible light.

1 is a partially exploded perspective view of a plasma display panel according to an embodiment of the present invention.

2-4 is partial sectional drawing of the 2nd board | substrate shown in FIG.

5 is a partial plan view of a plasma display panel showing a first modification to the embodiment of the present invention.

6 is a partial plan view of a plasma display panel showing a second modification to the embodiment of the present invention.

7 is a partial cross-sectional view of a second substrate among plasma display panels showing a third modification to the embodiment of the present invention.

8 is a partial cross-sectional view of the front substrate of the plasma display panel according to the prior art.

Claims (17)

First and second substrates disposed to face each other; Address electrodes formed on the first substrate and covered by a lower dielectric layer; A partition wall disposed in a space between the first substrate and the second substrate to form a discharge space; Red, green, and blue fluorescent layers formed in the discharge space; Discharge holding electrodes formed of a pair of scan electrodes and display electrodes formed on the second substrate and covered by an upper dielectric layer; And A protective film formed on a surface of the upper dielectric layer, The passivation layer includes a base layer formed on the surface of the upper dielectric layer with a uniform thickness, and a protrusion formed at a predetermined thickness on the base layer on the scan electrode and the display electrode to protrude toward the first substrate. The method of claim 1, And a bus electrode formed along one edge of the transparent electrode, wherein the scan electrode and the display electrode are formed in a stripe pattern. The method of claim 1, And a bus electrode having the scan electrode and the display electrode formed in a stripe pattern, and a transparent electrode extending from the bus electrode toward the inside of each discharge cell so as to face each other. The method of claim 1, And the protrusion is formed in a stripe pattern along the discharge sustaining electrode. The method of claim 1, And the protrusion is independently provided for each discharge cell, and is formed in a stripe pattern along the direction of the discharge sustaining electrode in each discharge cell. The method according to any one of claims 2 to 5, And the protrusion is formed to have a width greater than a width of the bus electrode and smaller than a width of the transparent electrode. The method of claim 1, And D1 and D2 satisfy the following conditions when a distance between the scan electrode and the display electrode is referred to as D1 and a distance between the two protrusions positioned on the scan electrode and the display electrode is referred to as D2. D2 / D1 ≥ 1.5 The method of claim 1, And a thickness of the protrusions 3 to 15 times the thickness of the base layer. The method of claim 8, And a thickness of the protruding portion is 5 to 10 times the thickness of the base layer. The method of claim 1, A plasma display panel in which both sides of the protrusion are inclined. The method of claim 10, And an inclination angle of the side surface of the protrusion relative to the normal of the second substrate is 3 ° or more. The method of claim 1, And the upper dielectric layer has a dielectric constant of 10 to 20. First and second substrates disposed to face each other; Address electrodes formed on the first substrate and covered by a lower dielectric layer; A partition wall disposed in a space between the first substrate and the second substrate to form a discharge space; Red, green, and blue fluorescent layers formed in the discharge space; Discharge holding electrodes formed of a pair of scan electrodes and display electrodes formed on the second substrate and covered by an upper dielectric layer; And A protective film formed on a surface of the upper dielectric layer, The passivation layer may include a base layer formed to have a uniform thickness on the upper dielectric layer surface, and a protrusion formed to have a predetermined thickness on the scan layer and the base layer on the display electrode to protrude toward the first substrate. And a spacing between the two protrusions disposed on the scan electrode and the display electrode is 1.5 times or more than the spacing between the scan electrode and the display electrode. First and second substrates disposed to face each other; Address electrodes formed on the first substrate and covered by a lower dielectric layer; A partition wall disposed in a space between the first substrate and the second substrate to form a discharge space; Red, green, and blue fluorescent layers formed in the discharge space; Discharge holding electrodes formed of a pair of scan electrodes and display electrodes formed on the second substrate and covered by an upper dielectric layer; And A protective film formed on a surface of the upper dielectric layer, The passivation layer includes a base layer having a uniform thickness on the upper dielectric layer surface, and a protrusion formed at a thickness of 3 to 15 times the thickness of the base layer in the base layer on the scan electrode and the display electrode. The method of claim 14, And a thickness of the protruding portion is 5 to 10 times the thickness of the base layer. First and second substrates disposed to face each other; Address electrodes formed on the first substrate and covered by a lower dielectric layer; A partition wall disposed in a space between the first substrate and the second substrate to form a discharge space; Red, green, and blue fluorescent layers formed in the discharge space; Discharge holding electrodes formed of a pair of scan electrodes and display electrodes formed on the second substrate and covered by an upper dielectric layer; And A protective film formed on a surface of the upper dielectric layer, The passivation layer may include a base layer having a uniform thickness on the surface of the upper dielectric layer, and a protrusion formed at an arbitrary thickness on the base layer on the scan electrode and the display electrode, protruding toward the first substrate and having both sides inclined. Plasma display panel. The method of claim 16, And an inclination angle of the side surface of the protrusion with respect to the normal of the second substrate is in a range of 3 to 60 degrees.