JP2011150826A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable PDP sufficiently removing water and impurity gas such as hydrocarbon or the like and suppressing deterioration of a protection layer and a phosphor. <P>SOLUTION: The plasma display panel 10 includes a front face substrate 11 in which a plurality of display electrode pairs 14, a dielectric layer 15 and a protection layer 16 are formed and a rear face substrate 17 in which a plurality of data electrodes 18, a base dielectric layer 19, barrier ribs 22, and a phosphor layer 23 are formed. The front substrate 11 and the rear substrate 17 are arranged face to face so that the display electrode pairs 14 and the data electrode 18 may cross and the periphery is sealed, and a hydrogen storing material 20 composed of a platinum group element is placed inside. The hydrogen storing material 20 is coated by a material having a higher ionization tendency than the hydrogen storing material 20. <P>COPYRIGHT: (C)2011,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. . The back substrate is formed of 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 And a phosphor layer.

  Then, the front substrate and the rear substrate are disposed opposite to each other so that the display electrode pair and the data electrode intersect with each other, and the 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 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 created in the front substrate production step and the rear substrate created 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 process, 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.

In such a sealing process, impure gases such as water (H ₂ O), carbon monoxide (CO), carbon dioxide (CO ₂ ), and hydrocarbon (C _n H _m ) are discharged from the frit and the like. A part of the impure gas is adsorbed inside the PDP. In the subsequent exhaust process, the internal space of the PDP is exhausted. However, it is difficult to completely exhaust the impure gas adsorbed inside the PDP, and a certain amount of impure gas remains inside the PDP.

It is known that the protective layer, the phosphor, and the like react with these impure gases to deteriorate their characteristics. In particular, water (H ₂ O) affects the protective layer, lowers the discharge start voltage of the discharge cells, and causes “bleeding” image quality degradation on the display screen. In addition, when a still image is displayed for a long time, “burn-in” occurs in which the image becomes an afterimage. Further, the hydrocarbon reduces the surface of the phosphor and lowers the emission luminance of the phosphor.

Therefore, it is important to reduce the impurity gas remaining in the inside of the PDP, particularly water and hydrocarbons, stabilize the discharge characteristics, suppress the change over time, and improve the reliability. As a method for removing these impure gases, for example, Patent Document 1 discloses crystalline aluminosilicate (xM ₂ O.yM ₂ O.yAl ₂ O ₃ .zSiO ₂ .nH ₂ O), γ-activated alumina (γ-Al An example is disclosed in which an adsorbent such as ₂ O ₃ ) or amorphous activated silica (SiO ₂ ) is placed inside the PDP to remove water. Patent Document 2 discloses an example in which a magnesium oxide film is provided outside the image display area inside the PDP to remove water.

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 ), and carbonization of these oxides An example in which an adsorbent to which a platinum group element as a hydrogen decomposition catalyst is added is disposed outside the image display area inside the PDP to remove hydrocarbons is disclosed. In Patent Document 4, metal getters such as zircon (Zr), titanium (Ti), vanadium (V), aluminum (Al), and iron (Fe) are provided on the partition inside the PDP to adsorb organic solvent components. An example is disclosed.

JP 2003-303555 A JP-A-5-342991 International Publication No. 2005/086668 Japanese Patent Laid-Open No. 2002-531918

  However, with the recent increase in screen size and definition of PDPs, the residual amount of impure gas increases. Therefore, in the above conventional example, it is difficult to sufficiently remove impurities such as water, hydrocarbons, and organic solvents, and there is a problem that the protective layer and the phosphor are deteriorated.

  An object of the present invention is to solve these problems and to provide a highly reliable PDP in which an impurity gas such as water and hydrocarbons is sufficiently removed and deterioration of a protective layer and a phosphor is suppressed.

  In order to solve the above-described conventional problems, the PDP of the present invention includes a front substrate on which a plurality of display electrode pairs, a dielectric layer, and a protective layer are formed, a plurality of data electrodes, a base dielectric layer, a barrier rib, and a phosphor. A rear substrate on which a layer is formed, and a front substrate and a rear substrate are arranged opposite to each other so that the display electrode pair and the data electrode intersect with each other, and the periphery is sealed, and hydrogen containing a platinum group element is contained inside In the PDP in which an occlusion material is disposed, the hydrogen occlusion material is coated with a material having a higher ionization tendency than the hydrogen occlusion material.

  According to such a configuration, since the hydrogen storage material disposed inside the PDP is suppressed from being excessively oxidized and has a stable hydrogen storage capacity, impurities such as water and hydrocarbons are sufficiently removed, A highly reliable PDP in which deterioration of the protective layer and the phosphor is suppressed can be realized.

  Further, the hydrogen storage material may be palladium, and a material having a higher ionization tendency than palladium may be coated on the hydrogen storage material. According to such a configuration, the ability of palladium, which has the highest hydrogen storage capacity, can be fully exerted, so image quality deterioration such as “bleeding” and “burn-in” and emission luminance reduction of the phosphor hardly occur. PDP can be realized.

  According to the PDP of the present invention, it is possible to provide a highly reliable PDP in which impurities such as water and hydrocarbons are sufficiently removed and deterioration of the protective layer and the phosphor is suppressed.

It is a disassembled perspective view which shows the structure of PDP in embodiment of this invention. It is the sectional view on the AA line of FIG. It is a figure which shows the hydrogen storage material in embodiment of this invention.

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

(Embodiment)
FIG. 1 is an exploded perspective view showing the structure of a PDP according to an embodiment of the present invention, and FIG. 2 is a detailed sectional view seen from the direction of arrow A in FIG. As shown in FIGS. 1 and 2, the PDP 10 includes a front substrate 11 and a back substrate 17.

  FIG. 1 is an exploded perspective view showing the structure of the PDP in the embodiment, and FIG. 2 is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 1 and 2, the PDP 10 includes a front substrate 11 and a back substrate 17.

1 and 2, a plurality of pairs of display electrodes 14 are formed on a glass front substrate 11 in parallel with each other by a scan electrode 12 and a sustain electrode 13. Scan electrode 12 and sustain electrode 13 are formed in a pattern that repeats in the arrangement of scan electrode 12 -sustain electrode 13 -sustain electrode 13 -scan electrode 12. The scanning electrode 12 is formed on a wide transparent electrode 12a 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 12b containing a metal such as (Ag) is stacked. Similarly, the sustain electrode 13 is formed by laminating a narrow bus electrode 13b on a wide transparent electrode 13a.

Further, a dielectric layer 15 and a protective layer 16 made of magnesium oxide (MgO) are formed so as to cover the display electrode pair 14. The dielectric layer 15 is made of bismuth oxide (Bi ₂ O ₃ ) -based low melting glass or zinc oxide (ZnO) -based low melting glass having a thickness of about 40 μm. The protective layer 16 is a thin film layer made of an alkaline earth oxide mainly composed of magnesium oxide (MgO) having a film thickness of about 0.8 μm. The protective layer 16 protects the dielectric layer 15 from ion sputtering and discharge start voltage, etc. It is provided to stabilize the discharge characteristics.

A plurality of parallel data electrodes 18 made of a highly conductive material mainly composed of silver (Ag) or the like are formed on the glass back substrate 17, and a base dielectric layer is formed so as to cover the data electrodes 18. 19 is formed. The underlying dielectric layer 19 may be bismuth oxide (Bi ₂ O ₃ ) -based low-melting glass similar to the dielectric layer 15, but titanium oxide (TiO ₂₎ so as to also serve as a visible light reflecting layer. ) May be mixed.

A grid-like barrier rib 22 is formed on the base dielectric layer 19, and phosphor layers 23 that emit red, green, and blue light are formed on the surface of the base dielectric layer 19 and the side surfaces of the barrier rib 22. . The partition wall 22 is formed to a height of about 0.12 mm using, for example, a low-melting glass material. The phosphor layer 23 is about 15 μm using BaMgAl ₁₀ O ₁₇ : Eu as a blue phosphor, Zn ₂ SiO ₄ : Mn as a green phosphor, (Y, Gd) BO ₃ : Eu as a red phosphor, and the like. The film thickness is formed.

The front substrate 11 and the rear substrate 17 are arranged to face each other so that the display electrode pair 14 and the data electrode 18 cross each other, and the outer peripheral portion thereof is sealed with a sealing material (not shown) such as a frit and discharged inside. A space is formed. A discharge gas containing xenon (Xe) or the like is sealed in the discharge space at a pressure of about 6 × 10 ⁴ Pa. The discharge space is partitioned into a plurality of sections by partition walls 22, and discharge cells 24 are formed at the intersections between the display electrode pairs 14 and the data electrodes 18. These discharge cells 24 discharge and emit light to display an image. The structure of the PDP 10 is not limited to that described above, and the shape of the partition wall 22 may be a stripe shape.

  As shown in FIG. 2, a hydrogen storage material 20 made of a platinum group element having a particle size of 0.1 μm to 20 μm is disposed on the surface of the protective layer 16 at a position facing the partition wall 22. As shown in FIG. 3, the surface of the hydrogen storage material 20 is partially coated with a second material 21 that is a material having a higher ionization tendency than the hydrogen storage material 20.

  Conventionally, a metal getter or an oxide getter has been used to remove water and hydrocarbons remaining inside the PDP 10. However, since the molecular diameters of these impure gases are large, they do not sufficiently penetrate into the getter, and the amount of impure gases adsorbed is limited. By the discharge of the PDP 10, the present inventors decompose impure gases such as water molecules and hydrocarbon molecules released from the protective layer 16, the partition wall 22, the phosphor layer 23, etc. into hydrogen atoms, oxygen atoms, and carbon atoms. I noticed that. Focusing on the fact that palladium and palladium-containing alloys are hydrogen storage materials that store a large amount of hydrogen, we thought that water and hydrocarbons could be removed by storing small diameter hydrogen atoms in these materials. .

  Therefore, the following experiment was conducted using platinum group elements. A powder of platinum group element such as platinum, ruthenium, rhodium, iridium, osmium, and palladium is kneaded with an organic binder, and the PDP 10 is applied to the surface of the protective layer 16 at a position facing the partition wall 22 using a spray method or the like. Created. An image was displayed using the PDP 10 thus created, and the presence or absence of “bleeding” and “burn-in” was visually confirmed for about 1000 hours. As a result, it was confirmed that the image quality deterioration due to “smudge” and “burn-in” was reduced, and that a certain reduction effect was obtained especially with palladium.

  However, the hydrogen storage material 20 composed of these platinum group elements undergoes a sealing step in which the PDP 10 is heated in an air atmosphere at 400 ° C. to 500 ° C. Therefore, the oxidation of the hydrogen storage material 20 proceeds excessively, the hydrogen storage ability of the original platinum group element cannot be fully exhibited, and impure gases such as water and hydrocarbons cannot be sufficiently removed. It was also confirmed.

  Therefore, as shown in FIG. 3, the hydrogen storage material 20 is partially coated with the second material 21 which is a material having a higher ionization tendency than the hydrogen storage material 20, and the hydrogen storage material 20 is excessively oxidized. Tried to suppress progress. In general, when two kinds of materials having different ionization tendencies come into contact with each other, oxidation of a material having a low ionization tendency can be suppressed. In the present embodiment, zinc, nickel, tin, or the like is used as the second material 21 having a higher ionization tendency than the hydrogen storage material 20 made of a platinum group element, but many elements can be used without being limited thereto.

  When the hydrogen storage material 20 having such a configuration was disposed inside the PDP 10, it was confirmed that there was no excessive oxidation of the hydrogen storage material 20 even after a heat sealing step at 400 ° C to 500 ° C.

  An image was displayed using the PDP 10 in which the hydrogen storage material 20 was disposed, and the presence or absence of “smear” and “burn-in” was visually confirmed for 1000 hours. As a result, it was confirmed that image quality deterioration due to “smudge” and “burn-in” was remarkably reduced. In particular, when palladium powder was used for the hydrogen storage material 20, it was confirmed that the image quality deterioration hardly occurred. As is clear from these experiments, when the second material 21 having a higher ionization tendency is coated on the hydrogen storage material 20 and disposed on the surface of the protective layer 16 at a position opposite to the barrier ribs 22, the discharge is accompanied. The hydrogen storage material 20 sufficiently stores the decomposed hydrogen. Therefore, water molecules and hydrocarbon molecules can be greatly reduced, the discharge characteristics can be stabilized, changes with time can be suppressed, and in addition, a decrease in luminance of the phosphor can be suppressed.

  In the present embodiment, an example in which the hydrogen storage material 20 is disposed on the surface of the protective layer 16 at a position facing the partition wall 22 so as not to prevent light transmission is shown. The hydrogen storage material 20 has the same effect regardless of the position of the PDP 10 such as the surface or inside of the phosphor layer 23 or the top surface of the partition wall 22.

  In the present embodiment, the surface of the hydrogen storage material 20 is partially coated with the second material 21. However, the coverage, which is the ratio of the coat to the surface, can be appropriately determined by material selection or the like, and it is desirable that at least a part of the surface of the hydrogen storage material 20 is exposed. Furthermore, any method can be applied as a method of coating the second material 21 on the surface of the hydrogen storage material 20.

  As described above, according to the PDP of the present invention, a stable hydrogen storage capacity is realized in order to suppress excessive progress of oxidation of the hydrogen storage material, and impure gases such as water and hydrocarbons are sufficiently supplied. Therefore, it is possible to realize a highly reliable PDP in which deterioration of the protective layer and the phosphor is suppressed.

  INDUSTRIAL APPLICABILITY According to the PDP of the present invention, impure gases such as water and hydrocarbons can be sufficiently removed, and deterioration of the protective layer and phosphor can be suppressed, so that it is useful as a highly reliable PDP.

10 PDP
DESCRIPTION OF SYMBOLS 11 Front substrate 12 Scan electrode 12a, 13a Transparent electrode 12b, 13b Bus electrode 13 Sustain electrode 14 Display electrode pair 15 Dielectric layer 16 Protective layer 17 Back substrate 18 Data electrode 19 Base dielectric layer 20 Hydrogen storage material 21 2nd material 22 partition wall 23 phosphor layer 24 discharge cell

Claims (2)

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, a base dielectric layer, barrier ribs, and a phosphor layer are formed, A plasma display panel in which the front substrate and the rear substrate are arranged to face each other so that the electrode pair and the data electrode intersect to seal the periphery, and a hydrogen storage material made of a platinum group element is arranged inside. The plasma display panel is characterized in that the hydrogen storage material is coated with a material having a higher ionization tendency than the hydrogen storage material. The plasma display panel according to claim 1, wherein the hydrogen storage material is palladium.

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