JP2010092791A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display panel which is suppressed in deterioration of a protective layer and a phosphor by sufficiently removing impurity gases such as water and hydrocarbon. <P>SOLUTION: The plasma display panel includes a front face substrate 21 at which a plurality of display electrode pairs, a dielectric layer 25, and the protective layer 26 are formed, and a rear face substrate 31 at which a plurality of data electrodes, barrier ribs 34, and a phosphor layer 35 are formed. In the plasma display panel, the front substrate 21 and the rear substrate 31 are arranged in opposition to each other so that the display electrode pairs and the data electrodes cross each other, and crystalline zeolite 38 containing platinum group is arranged inside thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plasma display panel used for image display.

  In recent years, a plasma display panel (hereinafter abbreviated as “PDP”) has been attracting attention as a color display device capable of realizing a thin and lightweight on a large screen.

  A typical AC surface discharge type PDP as a PDP has a large number of discharge cells formed between a front substrate and a rear substrate which are arranged to face each other. In the front substrate, a plurality of display electrode pairs each consisting of a pair of scan electrodes and sustain electrodes are formed in parallel on a glass substrate, and a dielectric layer and a protective layer are formed so as to cover the display electrode pairs. . Here, the protective layer is a thin film of an alkaline earth oxide such as magnesium oxide (MgO), and is provided to protect the dielectric layer from ion sputtering and to stabilize discharge characteristics such as a discharge start voltage. The back substrate is formed with a plurality of parallel data electrodes on a glass substrate, a dielectric layer so as to cover them, and a grid-like partition wall formed thereon, respectively, and the surface of the dielectric layer and the side surface of the partition wall A phosphor layer is formed on the substrate. Then, the front substrate and the rear substrate are disposed opposite to each other so that the display electrode pair and the data electrode are three-dimensionally crossed and sealed, and a discharge gas is sealed in the internal discharge space. Here, a discharge cell is formed at a portion where the display electrode pair and the data electrode face each other. Ultraviolet light is generated by gas discharge in each discharge cell of the PDP having such a configuration, and phosphors of red, green, and blue colors are excited and emitted by the ultraviolet light to perform color display.

  As a method of driving the PDP, a subfield method, that is, a method of performing gradation display by combining subfields to emit light after dividing one field period into a plurality of subfields. The subfield has an initialization period, an address period, and a sustain period. In the initializing period, initializing discharge is generated in each discharge cell, and wall charges necessary for the subsequent address discharge are formed. In the address period, address discharge is selectively generated in the discharge cells to be displayed, and wall charges necessary for the subsequent sustain discharge are formed. In the sustain period, a sustain pulse is alternately applied to the scan electrode and the sustain electrode, a sustain discharge is generated in the discharge cell that has caused the address discharge, and the phosphor layer of the corresponding discharge cell emits light to display an image. Do.

  The PDP is manufactured through a front substrate manufacturing process, a back substrate manufacturing process, a sealing process, an exhaust process, and a discharge gas supply process. Here, the sealing step is a step of bonding the front substrate produced in the front substrate production step and the rear substrate produced in the back substrate production step, and the exhausting step is a step of exhausting gas from the space inside the PDP. In the sealing step, since the front substrate and the rear substrate are bonded together using frit, they are superposed and fired at a temperature equal to or higher than the softening point temperature of the frit, for example, about 440 ° C. to 500 ° C.

At this time, impure gases such as water (H ₂ O), carbon dioxide (CO, CO ₂ ), and hydrocarbons (CnHm) are discharged from the frit and the like, and some of these impure gases are adsorbed inside the PDP. In addition, although the impure gas is exhausted together with the air inside the PDP in the subsequent exhaust process, it is difficult to exhaust completely including the impure gas adsorbed inside the PDP, and a certain amount of impure gas remains inside the PDP. That was inevitable. In addition, with the recent increase in screen size and resolution of PDPs, the residual amount of impure gas tends to increase.

  However, it is known that materials such as a protective layer and a phosphor react with an impure gas to deteriorate its characteristics. In particular, a large amount of water remaining inside the PDP adversely affects the discharge characteristics of the protective layer, lowers the discharge start voltage of the discharge cells, and causes a “bleeding” image quality deterioration on the display screen. However, when a still image is displayed for a long time, there is a problem that “burn-in” occurs in which the image becomes an afterimage. Hydrocarbons also have problems such as reducing the surface of the phosphor and lowering the emission luminance of the phosphor.

Therefore, it is one of the important issues to reduce the impurity gases remaining in the PDP, particularly water and hydrocarbons, stabilize the discharge characteristics, and suppress the change with time. As a method for removing these impure gases, for example, Patent Document 1 discloses an attempt to remove water by disposing an adsorbent such as crystalline aluminosilicate, γ-activated alumina or amorphous activated silica inside the PDP. Has been. Patent Document 2 describes an attempt to remove water by providing a magnesium oxide film in a region other than the image display region inside the PDP. Further, Patent Document 3 discloses alumina (Al ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ), lanthanum oxide (La ₂ O ₃ ), magnesium oxide (MgO), nickel oxide (NiO), and manganese oxide (MnO). , Oxides such as chromium oxide (CrO ₂ ), zirconium oxide (ZrO ₂ ), iron oxide (Fe ₂ O ₃ ), barium titanate (BaTiO ₃ ), titanium oxide (TiO ₂ ), etc. An attempt to remove hydrocarbon gas by placing an adsorbent added with a platinum group element as a decomposition catalyst in a region other than the image display region inside the PDP is described. In Patent Document 4, metal getters such as zircon (Zr), titanium (Ti), vanadium (V), aluminum (Al), and iron (Fe) are provided on the partition walls inside the PDP to absorb the organic solvent. An attempt to do is described.
JP 2003-303555 A JP-A-5-342991 International Publication No. 2005/086668 Pamphlet Japanese Patent Laid-Open No. 2002-531918

  However, despite the various attempts described above, it is difficult to sufficiently remove impurities such as water, hydrocarbons, and organic solvents, and it is difficult to suppress deterioration of the protective layer and the phosphor.

  The present invention has been made in view of such a current situation, and an object of the present invention is to provide a PDP in which impurity gases such as water and hydrocarbons are sufficiently removed and deterioration of a protective layer and a phosphor is suppressed.

  In order to achieve this object, the present invention provides a front substrate on which a plurality of display electrode pairs, a dielectric layer, and a protective layer are formed, a back substrate on which a plurality of data electrodes, barrier ribs, and a phosphor layer are formed. The display electrode pair and the data electrode are arranged so that the front substrate and the rear substrate face each other so that the display electrode pair and the data electrode intersect, and the crystalline zeolite containing a platinum group is disposed inside. Features. With this configuration, it is possible to provide a PDP in which impurity gases such as water and hydrocarbons are sufficiently removed and deterioration of the protective layer and the phosphor is suppressed.

  In the PDP of the present invention, a crystalline zeolite containing a platinum group may be disposed on the phosphor layer or inside the phosphor layer.

  In the PDP of the present invention, a crystalline zeolite containing a platinum group may be disposed on the surface of the partition wall or inside the partition wall.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide PDP which fully removed impurity gases, such as water and a hydrocarbon, and suppressed degradation of a protective layer and fluorescent substance.

  Hereinafter, a PDP according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is an exploded perspective view showing a schematic structure of a PDP according to Embodiment 1 of the present invention. The PDP 10 is configured by bonding a glass front substrate 21 and a back substrate 31 together. On the front substrate 21, a plurality of display electrode pairs 24 including scan electrodes 22 and sustain electrodes 23 are formed. A dielectric layer 25 is formed so as to cover the display electrode pair 24, and a protective layer 26 is formed on the dielectric layer 25. A plurality of data electrodes 32 are formed on the back substrate 31, a dielectric layer 33 is formed so as to cover the data electrodes 32, and a grid-like partition wall 34 is formed thereon. A phosphor layer 35 that emits red, green, and blue light is applied on the side surfaces of the partition walls 34 and the dielectric layer 33.

  In the first embodiment, a crystalline zeolite containing a platinum group is disposed on the phosphor layer 35. FIG. 2 is a sectional view showing a schematic structure of the PDP according to the first embodiment of the present invention, in which a crystalline zeolite 38 containing a platinum group is dispersed on a phosphor layer 35 applied on a back substrate 31. It shows how it is. In the first embodiment, crystalline zeolite 38 having a particle diameter of 0.1 μm to 20 μm with palladium deposited on the surface by electroless plating is used. The crystalline zeolite 38 containing the platinum group has a covering rate of 50% or less so that the crystalline zeolite 38 containing the platinum group covers the phosphor layer 35 so as not to hinder the emission of the phosphor.

  FIG. 2 schematically shows a state in which the crystalline zeolite 38 containing a platinum group is dispersed so as to be scattered on the surface (surface) of the phosphor layer 35. The same effect can be obtained by dispersing the crystalline zeolite 38 containing a platinum group therein.

  The front substrate 21 and the rear substrate 31 are arranged to face each other so that the display electrode pair 24 and the data electrode 32 intersect with each other with a minute discharge space interposed therebetween, and a sealing material (not shown) such as a frit is provided on the outer periphery. Z)). A discharge gas containing, for example, xenon (Xe) or the like is sealed in the discharge space. The discharge space is partitioned into a plurality of sections by partition walls 34, and discharge cells are formed at the intersections between the display electrode pairs 24 and the data electrodes 32. These discharge cells discharge and emit light to display an image. Note that the structure of the PDP 10 is not limited to that described above. For example, the dielectric layer 33 may be omitted, and the shape of the partition wall 34 may be a stripe shape.

Next, the material of the PDP 10 will be described. The scanning electrode 22 is formed on a wide transparent electrode 22a made of a conductive metal oxide such as indium tin oxide (ITO), tin oxide (SnO ₂ ), or zinc oxide (ZnO), in order to increase conductivity. A narrow bus electrode 22b containing a metal such as (Ag) is laminated. Similarly, the sustain electrode 23 is formed by laminating a narrow bus electrode 23b on a wide transparent electrode 23a. The dielectric layer 25 is made of bismuth oxide low melting glass or zinc oxide low melting glass. The protective layer 26 is a thin film layer made of an alkaline earth oxide mainly composed of magnesium oxide. The data electrode 32 is made of a highly conductive material containing a metal such as silver. The dielectric layer 33 may be made of the same material as that of the dielectric layer 25, but may be made of a material in which titanium oxide particles are mixed so as to also serve as a visible light reflecting layer. The partition wall 34 is formed using, for example, a low melting point glass material. The phosphor layer 35 can use BaMgAl ₁₀ O ₁₇ : Eu as a blue phosphor, Zn ₂ SiO ₄ : Mn as a green phosphor, and (Y, Gd) BO ₃ : Eu as a red phosphor. Of course, the phosphor is not limited to the above phosphor.

  The platinum group of the crystalline zeolite 38 containing a platinum group is any one or more of platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), and osmium (Os). The platinum group can be used, but palladium is particularly desirable. Further, as the crystalline zeolite 38 containing a platinum group, at least one of platinum, palladium, ruthenium, rhodium, iridium, and osmium and transition metals such as titanium (Ti), manganese (Mn), zirconium (Zr), nickel A compound with any one of (Ni), cobalt (Co), lanthanum (La), iron (Fe), and vanadium (V) can also be used. In this case, an alloy containing palladium is also desirable.

  As a method of including the platinum group in the crystalline zeolite, a sputtering method or an ion implantation method can be used, but it is desirable to use an electroless plating method.

  As a method of dispersing the crystalline zeolite 38 containing a platinum group on the phosphor layer 35, for example, a spray method can be used. As a method for dispersing the crystalline zeolite 38 containing a platinum group in the phosphor layer 35, the crystalline zeolite 38 containing a platinum group may be mixed in advance when the phosphor layer 35 is formed. The particle size of the platinum group powder is desirably 0.1 μm to 20 μm, and the mixing ratio is desirably about 0.01% to 2% with respect to the phosphor powder. Since the phosphor layer 35 has a low phosphor filling rate of 60% or less, the effect of occluding moisture and hydrogen is maintained even if the crystalline zeolite 38 containing a platinum group is dispersed inside the phosphor layer 35.

Note that the film thickness of the dielectric layer 25 of the PDP 10 in the present embodiment described above is, for example, 40 μm, and the film thickness of the protective layer 26 is, for example, 0.8 μm. Further, the height of the partition wall 34 is, for example, 0.12 mm, and the thickness of the phosphor layer 35 is, for example, 15 μm. The discharge gas is, for example, a mixed gas of neon (Ne) and xenon (Xe), the gas pressure of the discharge gas is, for example, 6 × 10 ⁴ Pa, and the xenon content is, for example, 10% by volume or more.

  Next, the function of the crystalline zeolite 38 containing a platinum group will be described. Conventionally, metal getters and oxide getters have been used to remove water and hydrocarbons, but these impure gases have large molecular diameters, so they do not penetrate well into the getter and limit the amount of impure gas adsorbed. was there.

  The present inventors discharge impure gas from the protective layer, barrier rib, phosphor layer, etc. by discharging the PDP, and the water molecules and hydrocarbon molecules therein are decomposed into hydrogen atoms, oxygen atoms, and carbon atoms. I noticed that. Focusing on the fact that platinum group elements have the property of occluding a large amount of hydrogen, we thought that by removing hydrogen atoms with a small radius in platinum group elements, water and hydrocarbons could be removed as a result. .

  The present inventors have prepared powders of white metal elements (platinum, palladium, ruthenium, rhodium, iridium, osmium) or white metal elements and transition metals (titanium, manganese, zirconium, nickel, cobalt, lanthanum, iron, vanadium). A PDP was produced by applying the above alloy powder onto the phosphor layer, the top of the partition, the protective layer, and the like using a printing method, a spray method, a photolithography method, a dispenser method, an ink jet method, and the like. The powder of the white metal element was used as a paste by kneading with an organic binder as necessary. Further, the place where the white metal element is applied is a place where electric discharge is generated at the time of displaying an image of the PDP or the vicinity thereof.

  Images were displayed using the PDP produced in this manner, and the presence or absence of “bleeding” and “burn-in” was visually confirmed for about 1000 hours. As a result, it was confirmed that image quality deterioration due to “smudge” and “burn-in” was reduced. In particular, when powder containing palladium was used, it was confirmed that the image quality deterioration hardly occurred. Further, it was confirmed that when the powder containing palladium was used, the light emission luminance of the phosphor hardly decreased. This is because water molecules and hydrocarbon molecules are decomposed into hydrogen atoms, oxygen atoms, and carbon atoms, and platinum group elements, particularly palladium, occlude a large amount of hydrogen. This is thought to be due to a significant decrease in hydrocarbon molecules.

  As is clear from this experiment, when used as a crystalline zeolite containing a white metal element, particularly palladium as a platinum group, impure gas released from the protective layer, partition walls, phosphor layers, etc. by the crystalline zeolite, particularly moisture and carbonization. Absorbs most of the hydrogen gas, and the remaining moisture and hydrocarbon molecules are decomposed by the discharge and occludes hydrogen generated by the platinum group such as palladium. In addition, it is possible to stabilize the discharge characteristics, suppress the change with time, and suppress the decrease in luminance of the phosphor.

  In Embodiment 1, crystalline zeolite containing a platinum group is dispersed on the surface or inside of the phosphor layer 35, but the present invention is not limited to this.

  Therefore, an embodiment in which a crystalline zeolite containing a platinum group is disposed in another place will be described below.

(Embodiment 2)
The PDP according to the second embodiment is different from the first embodiment in that a crystalline zeolite 38 containing a platinum group is disposed on the surface of the partition wall 34, particularly on the top of the partition wall 34. FIG. 3 is a diagram showing a schematic structure of the PDP 10 according to the second embodiment of the present invention in a cross-sectional view, and is a diagram schematically showing a state in which a crystalline zeolite 38 containing a platinum group is arranged at the top of the partition wall 34. .

  The particle size of the platinum group powder used in the second embodiment must be such that no large gap is generated between the partition wall 34 and the protective layer 26, and is preferably 0.1 μm to 5 μm. Further, the thickness of the platinum group powder layer is desirably 5 μm or less, and may be such that platinum group powder is scattered on the top of the partition wall 34.

  In the second embodiment, the crystalline zeolite 38 containing a platinum group is arranged at the top of the partition wall 34. However, the crystalline zeolite 38 containing a platinum group is arranged on the surface of the partition wall 34 other than the top of the partition wall 34. Also good. In the case where the partition wall 34 has a porous structure, the same effect can be obtained even when the crystalline zeolite 38 containing a platinum group is present inside the partition wall 34.

(Embodiment 3)
The PDP in the third embodiment is different from the first embodiment in that a crystalline zeolite 38 containing a platinum group is disposed on the protective layer 26 of the front substrate 21. FIG. 4 is a cross-sectional view showing a schematic structure of the PDP 10 according to Embodiment 3 of the present invention, and is a view schematically showing a state in which a crystalline zeolite 38 containing a platinum group is dispersed on the protective layer 26. .

  Also in the third embodiment, as in the second embodiment, the particle size of the platinum group powder must be such that a large gap is not generated between the partition wall 34 and the protective layer 26, and 0.1 μm to 5 μm is desirable. Further, it is desirable that the covering ratio of the platinum group powder covering the protective layer 26 is 50% or less so that the platinum group powder does not hinder visible light transmission.

  As described above in Embodiments 1 to 3, in Embodiments 1 to 3, a crystalline zeolite containing a platinum group containing palladium is arranged inside the PDP. In the first to third embodiments, the impure gas having a large molecular diameter such as water molecules and hydrocarbon molecules is not adsorbed as it is, but most of the moisture and hydrocarbon gases are absorbed by the crystalline zeolite and absorbed. Water and hydrocarbons are greatly reduced by disposing a crystalline zeolite containing a platinum group such as palladium that absorbs a large amount of the generated hydrogen and decomposes with no residual moisture and hydrocarbon molecules inside the PDP. I am letting. As a result, it is possible to stabilize the discharge characteristics, suppress a change with time, and suppress a decrease in luminance of the phosphor.

  It should be noted that the specific numerical values used in the first to third embodiments are merely examples, and it is desirable to appropriately set the optimal values according to the specifications of the PDP and the specifications of the PDP material. .

  As described above, the present invention is useful for providing a large-screen, high-definition PDP.

1 is an exploded perspective view showing a schematic structure of a PDP according to Embodiment 1 of the present invention. Sectional drawing which shows schematic structure of PDP by Embodiment 1 of this invention Sectional drawing which shows schematic structure of PDP by Embodiment 2 of this invention Sectional drawing which shows schematic structure of PDP by Embodiment 3 of this invention

Explanation of symbols

10 Plasma display panel (PDP)
21 Front substrate 22 Scan electrode 23 Sustain electrode 24 Display electrode pair 25 Dielectric layer 26 Protective layer 31 Back substrate 32 Data electrode 33 Dielectric layer 34 Partition 35 Phosphor layer 38 Crystalline zeolite containing platinum group

Claims (3)

A front substrate on which a plurality of display electrode pairs, a dielectric layer, and a protective layer are formed; and a rear substrate on which a plurality of data electrodes, barrier ribs, and phosphor layers are formed, and the display electrode pair and the data A plasma display panel comprising: a front substrate and a rear substrate facing each other so as to intersect with electrodes; and a crystalline zeolite containing a platinum group disposed therein. The plasma display panel according to claim 1, wherein the crystalline zeolite containing the platinum group is disposed on the phosphor layer or inside the phosphor layer. The plasma display panel according to claim 1, wherein the crystalline zeolite containing the platinum group is disposed on a surface of the partition wall or inside the partition wall.

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