JP2012227083A - Plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display panel (PDP) capable of improving luminance life of a green phosphor and a driving voltage of PDP.SOLUTION: A phosphor layer of the plasma display panel is a green phosphor layer including a mixture of ZnSiO:Mn and (Y,Gd)(Al,Ga)O:Ce, where 0≤x≤1,0≤y≤0.5, and a surface of the ZnSiO:Mn is covered with metal oxide and the outermost surface of the ZnSiO:Mn covered with metal oxide is covered with aluminum oxide.

Description

  The present invention relates to a plasma display panel having a phosphor layer containing a phosphor excited by vacuum ultraviolet rays.

  In recent years, plasma display panels (hereinafter referred to as PDPs) are attracting attention as color display devices that can be large, thin, and lightweight as color display devices used for image display in computers and televisions. The PDP performs full color display by additively mixing the so-called three primary colors of red, green, and blue. In order to perform this full-color display, a phosphor layer that emits each of the three primary colors is provided. The phosphor particles constituting the phosphor layer are excited by ultraviolet light emitted in the PDP discharge cell to generate visible light of each color.

  Here, the moving picture quality of the PDP greatly depends on the afterglow characteristics of the red, green and blue phosphors. If the phosphor has a 1/10 afterglow time (hereinafter simply referred to as afterglow time) of 8 msec or more, it is visually recognized that the light emission has a tail, and the display image quality deteriorates. Further, if it is 4 msec or less, the afterglow becomes difficult to be seen by human eyes, and the display image quality is improved.

Among phosphors used for PDP, green phosphors have a long afterglow time of 10 msec or longer for commonly used Zn ₂ SiO ₄ : Mn and (Y, Gd) BO ₃ : Tb. Therefore, Patent Document 1 discloses mixing (Y, Gd) Al ₃ (BO ₃ ) ₄ : Tb having a short afterglow time. However, the green phosphor made of Zn ₂ SiO ₄ : Mn is easily charged to negative polarity unlike the red phosphor and the blue phosphor. For this reason, it is known that when used in a PDP, the discharge characteristics are deteriorated, which contributes to a decrease in luminous efficiency of the PDP.

Therefore, in order to improve negative charging, Patent Documents 2 and 3 disclose a method of densely coating a negatively charged Zn ₂ SiO ₄ : Mn surface with a positively charged oxide until the polarity becomes positive. In particular, Patent Document 3 discloses a plasma display device (hereinafter referred to as a PDP device) having high luminance and small luminance deterioration by coating the surface of Zn ₂ SiO ₄ : Mn phosphor particles with magnesium oxide (MgO). A method of realizing is disclosed.

JP-A-10-195428 Japanese Patent Laid-Open No. 11-86735 International Publication WO2007-097327

However, even if (Y, Gd) Al ₃ (BO ₃ ) ₄ : Tb is mixed with Zn ₂ SiO ₄ : Mn (usually 8 to 14 msec), the color gamut becomes narrow and the afterglow time should be 4 msec or less. I can't. Further, when the surface of the Zn ₂ SiO ₄ : Mn phosphor particles is coated with a positively charged metal oxide, an impurity gas derived from the metal oxide is mixed into the PDP, and the voltage characteristics are deteriorated. Among positively charged metal oxides, especially alkaline earth metal oxides such as MgO are strongly basic, and thus have a high reactivity with carbon dioxide gas, and many impurity gases are brought into the PDP. As a result, the drive voltage increases and the power consumption increases.

  An object of the present invention is to provide a high-performance PDP device that solves the above problems and suppresses an increase in driving voltage and reduces power consumption.

In order to achieve the above object, a PDP apparatus of the present invention has a front substrate transparent at least on the front side and a rear substrate opposed to each other via a discharge space, and a partition for partitioning the discharge space into a plurality of rear substrates. And a plasma display panel provided with a phosphor layer on which electrodes are arranged on the front substrate and the rear substrate so that discharge is generated in a discharge space partitioned by partition walls and which emits light by discharge a display apparatus, the phosphor layer, Zn ₂ SiO _4: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: Ce ( provided that, 0 ≦ x ≦ 1 , 0 ≦ y ≦ 0.5), the surface of Zn ₂ SiO ₄ : Mn is coated with a metal oxide, and further Zn ₂ SiO ₄ : Mn coated with a metal oxide The outermost surface of the aluminum oxide Characterized in that it is coated with bromide.

  As described above, according to the PDP of the present invention, a PDP device having a long life, low power consumption, and high brightness can be realized.

The disassembled perspective view which shows the principal part of the panel used for the plasma display apparatus in embodiment of this invention. PDP electrode arrangement diagram of plasma display device according to an embodiment of the present invention The figure showing the cross section of PDP of the plasma display apparatus by embodiment of this invention

  Hereinafter, a plasma display device according to Embodiment 1 of the present invention will be described with reference to FIGS. However, the embodiment of the present invention is not limited to this.

<Embodiment 1>
1. Configuration of PDP FIG. 1 is an exploded perspective view showing a front panel 1 and a rear panel 2 separated from each other in a PDP according to a first embodiment of the present invention, and FIG. 2 is a plasma display device according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a discharge cell structure when the front plate 1 and the back plate 2 are bonded to form a PDP.

  As shown in FIG. 1, the PDP is configured by disposing a glass front substrate 4 and a rear substrate 10 so as to form a discharge space 3 therebetween.

  The front plate 1 has a scanning electrode 5 as a conductive first electrode and a sustain electrode 6 as a second electrode arranged on a glass front substrate 4 in parallel with each other with a discharge gap MG. A plurality of display electrodes 7 are arranged in the row direction, and a dielectric layer 8 made of a glass material is formed so as to cover the scan electrodes 5 and the sustain electrodes 6. A protective layer 9 made of MgO is formed on 8. The scan electrode 5 and the sustain electrode 6 are each a bus having a thickness of about several μm made of a transparent electrode such as ITO and a conductive metal such as Ag formed so as to be electrically connected to the transparent electrode. And electrodes. The back plate 2 is provided with a plurality of data electrodes 12 made of Ag covered with an insulating layer 11 made of a glass material and arranged in a stripe shape in the column direction on a glass back substrate 10, and On the insulator layer 11, a grid-like partition wall 13 made of a glass material for partitioning the discharge space 3 between the front plate 1 and the back plate 2 for each discharge cell is provided. Further, red (R), green (G), and blue (B) phosphor layers 14R, 14G, and 14B are provided on the surface of the insulator layer 11 and the side surfaces of the partition walls 13. The front plate 1 and the back plate 2 are arranged to face each other so that the scan electrode 5 and the sustain electrode 6 intersect with the data electrode 12, and the scan electrode 5, the sustain electrode 6 and the data electrode 12 intersect at the intersecting portion. As shown in FIG. 2, a discharge cell 15 is provided. The discharge space 3 is filled with, for example, a mixed gas of neon and xenon as a discharge gas. Note that the structure of the PDP is not limited to that described above, and for example, a structure having stripe-shaped partition walls may be used.

  Here, as shown in FIG. 3, the cross-shaped barrier ribs 13 forming the discharge cells 15 include a vertical barrier rib 13a formed in parallel to the data electrode 12, and a horizontal barrier rib formed so as to be orthogonal to the vertical barrier rib 13a. 13b. The phosphor layers 14R, 14G, and 14B formed by coating in the barrier ribs 13 are formed of stripes of blue phosphor layers 14B, red phosphor layers 14R, and green phosphor layers 14G along the vertical barrier ribs 13a. They are arranged in order.

  FIG. 2 is an electrode array diagram of the PDP shown in FIG. N scanning electrodes Y1, Y2, Y3... Yn (5 in FIG. 1) and n sustaining electrodes X1, X2, X3... Xn (6 in FIG. 1) are arranged in the row direction. . Then, m data electrodes A1... Am (12 in FIG. 1) that are long in the column direction are arranged. Further, discharge cells 15 are formed at the intersections of the pair of scan electrodes Y1 and sustain electrodes X1 and one data electrode A1, and m × n discharge cells 15 are formed in the discharge space. Further, as shown in FIG. 2, the scan electrode Y1 and the sustain electrode X1 are formed on the front plate 1 in a pattern that repeats in the arrangement of the scan electrode Y1, the sustain electrode X1, the sustain electrode X2, the scan electrode Y2,. Has been. Each of these electrodes is connected to a connection terminal provided at a peripheral end portion outside the image display area of the front plate 1 and the back plate 2.

2. PDP manufacturing method 2-1. Front plate manufacturing method Scan electrodes 5 and sustain electrodes 6 are formed on front substrate 4 by photolithography. The scanning electrode 5 is composed of a transparent electrode such as indium tin oxide (ITO) and a bus electrode made of silver (Ag) laminated on the transparent electrode. The sustain electrode 6 includes a transparent electrode such as ITO and a bus electrode made of Ag or the like laminated on the transparent electrode. As a material for the bus electrode, an electrode paste containing silver (Ag), a glass frit for binding silver, a photosensitive resin, a solvent, and the like is used. First, an electrode paste is applied on the front substrate 4 on which a transparent electrode is formed by a screen printing method. Next, the solvent in the electrode paste is removed by a drying furnace. Next, the electrode paste is exposed through a photomask having a predetermined pattern. Next, the electrode paste is developed to form a bus electrode pattern. Finally, the bus electrode pattern is fired at a predetermined temperature in a firing furnace. That is, the photosensitive resin in the electrode pattern is removed. Further, the glass frit in the electrode pattern is melted. Thereafter, the glass frit that has been melted is vitrified by cooling to room temperature. A bus electrode is formed by the above process. Here, besides the method of screen printing the electrode paste, a sputtering method or a vapor deposition method can be used. Next, the dielectric layer 8 is formed. As a material for the dielectric layer 8, a dielectric paste containing a dielectric glass frit, a resin, a solvent, and the like is used. For example, the dielectric layer 8 is made of bismuth oxide (Bi ₂ O ₃ ) -based low melting glass or zinc oxide (ZnO) low-melting glass having a thickness of about 40 μm. First, a dielectric paste is applied on the front substrate 4 by a die coating method so as to cover the scan electrodes 5 and the sustain electrodes 6 with a predetermined thickness. Next, the solvent in the dielectric paste is removed by a drying furnace. Finally, the dielectric paste is fired at a predetermined temperature in a firing furnace. That is, the resin in the dielectric paste is removed. Further, the dielectric glass frit is melted. Thereafter, the cooled dielectric glass frit is vitrified by cooling to room temperature. Through the above steps, the dielectric layer 8 is formed. Here, besides the method of die coating the dielectric paste, a screen printing method or a spin coating method can be used. Alternatively, a film that becomes the dielectric layer 8 can be formed by CVD (Chemical Vapor Deposition) without using the dielectric paste. Next, the protective layer 9 is formed on the dielectric layer 8. The protective layer 9 is a thin film layer made of an alkaline earth metal oxide mainly composed of magnesium oxide (MgO) having a film thickness of about 0.8 μm. The protective layer 9 protects the dielectric layer 8 from ion sputtering and discharge start voltage. Is provided to stabilize the discharge characteristics.

  Through the above steps, the front plate 1 having the scan electrode 5, the sustain electrode 6, the dielectric layer 8, and the protective layer 9 on the front substrate 4 is completed.

2-2. Manufacturing Method of Back Plate Data electrodes 12 are formed on the back substrate 10 by photolithography. As a material of the data electrode 12, a data electrode paste containing silver (Ag) for ensuring conductivity, a glass frit for binding silver, a photosensitive resin, a solvent, and the like is used. First, the data electrode paste is applied on the back substrate 10 with a predetermined thickness by screen printing. Next, the solvent in the data electrode paste is removed by a drying furnace. Next, the data electrode paste is exposed through a photomask having a predetermined pattern. Next, the data electrode paste is developed to form a data electrode pattern. Finally, the data electrode pattern is fired at a predetermined temperature in a firing furnace. That is, the photosensitive resin in the data electrode pattern is removed. Further, the glass frit in the data electrode pattern is melted. Thereafter, the glass frit that has been melted is vitrified by cooling to room temperature. The data electrode 12 is formed by the above process. Here, besides the method of screen printing the data electrode paste, a sputtering method or a vapor deposition method can be used.

Next, the insulator layer 11 is formed. As a material of the insulator layer 11, an insulator paste containing an insulator glass frit, a resin, a solvent, and the like is used. For example, the insulator layer 11 may be bismuth oxide (Bi ₂ O ₃ ) -based low-melting glass similar to the dielectric layer 8, but titanium oxide (TiO 2) so as to also serve as a visible light reflecting layer. ₂ ) A material in which particles are mixed may be used. First, an insulating paste is applied by screen printing so as to cover the data electrode 12 on the back substrate 10 on which the data electrode 12 is formed with a predetermined thickness. Next, the solvent in the insulator paste is removed by a drying furnace. Finally, the insulator paste is fired at a predetermined temperature in a firing furnace. That is, the resin in the insulator paste is removed. Moreover, the insulator glass frit is melted. Thereafter, by cooling to room temperature, the molten insulator glass frit is vitrified. The insulator layer 11 is formed by the above process. Here, in addition to the method of screen printing the insulator paste, a die coating method or a spin coating method can be used. In addition, a film that becomes the insulator layer 11 can be formed by a CVD (Chemical Vapor Deposition) method without using the insulator paste.

  Next, the partition wall 13 is formed by photolithography. As a material of the partition wall 13, a partition wall paste including a filler, a glass frit for binding the filler, a photosensitive resin, a solvent, and the like is used. First, the barrier rib paste is applied on the insulator layer 11 with a predetermined thickness by a die coating method. Next, the solvent in the partition wall paste is removed by a drying furnace.

  Next, the barrier rib paste is exposed through a photomask having a predetermined pattern. Next, the barrier rib paste is developed to form a barrier rib pattern. Finally, the partition pattern is fired at a predetermined temperature in a firing furnace. That is, the photosensitive resin in the partition pattern is removed. Further, the glass frit in the partition wall pattern is melted. Thereafter, the glass frit that has been melted is vitrified by cooling to room temperature. The partition wall 13 is formed by the above process. Here, in addition to the photolithography method, a sand blast method can be used. The partition wall 13 is formed to a height of about 0.12 mm using, for example, a low-melting glass material. In the embodiment, the height of the partition wall 13 is 0.1 mm to 0.15 mm and the pitch of the adjacent partition wall 13 is 0.15 mm in accordance with a full high-definition television having a screen size of 42 inches. The structure of the PDP is not limited to that described above, and the shape of the partition wall 13 may be a stripe shape.

  Next, the phosphor layer 14 is formed. As a material for the phosphor layer 14, a phosphor paste containing phosphor particles, a binder, a solvent, and the like is used. First, the phosphor paste is applied on the insulating layer 11 between the adjacent barrier ribs 13 and on the side surfaces of the barrier ribs 13 with a predetermined thickness by a dispensing method. Next, the solvent in the phosphor paste is removed by a drying furnace. Finally, the phosphor paste is fired at a predetermined temperature in a firing furnace. That is, the resin in the phosphor paste is removed. The phosphor layer 14 is formed by the above steps. Here, in addition to the dispensing method, a screen printing method can be used.

  Through the above steps, the back plate 2 having the data electrode 12, the insulator layer 11, the partition wall 13, and the phosphor layer 14 on the back substrate 10 is completed.

2-3. Assembly Method of Front Plate and Back Plate First, a sealing paste is applied around the back plate 2 by a dispensing method. The applied sealing paste forms a sealing paste layer (not shown). Next, the solvent in the sealing paste layer is removed by a drying furnace. Thereafter, the sealing paste layer is temporarily fired at a temperature of about 350 ° C. The resin component etc. in the sealing paste layer are removed by temporary baking. Next, the front plate 1 and the back plate 2 are arranged to face each other so that the display electrode 7 and the data electrode 12 are orthogonal to each other. Further, the peripheral portions of the front plate 1 and the back plate 2 are held in a state of being pressed by a clip or the like. In this state, the low melting point glass material is melted by firing at a predetermined temperature. Then, the low-melting-point glass material that has been melted is vitrified by cooling to room temperature. Thereby, the front plate 1 and the back plate 2 are hermetically sealed. Finally, a discharge gas containing Ne, Xe or the like is enclosed in the discharge space 3. The composition of the discharge gas to be sealed is the Ne-Xe system conventionally used, but the Xe content is set to 5% by volume or more, and the sealing pressure is set to a range of 55 kPa to 80 kPa. This completes the PDP.

3. Structure of phosphor material and manufacturing method thereof Next, a phosphor material of each color and a manufacturing method of the phosphor material will be described. In the present embodiment, a phosphor material manufactured by a solid phase reaction method is used.

3-1. Configuration of Blue Phosphor and Manufacturing Method Thereof First, the blue phosphor material will be described. In the embodiment of the present invention, a blue phosphor material of BaMgAl ₁₀ O ₁₇ : Eu having a short afterglow time is used as the blue phosphor layer 14B. BaMgAl ₁₀ O ₁₇ : Eu, which is a blue phosphor material, is produced by the following method.

Barium carbonate (BaCO ₃ ), magnesium carbonate (MgCO ₃ ), aluminum oxide (Al ₂ O ₃ ), and europium oxide (Eu ₂ O ₃ ) are mixed so as to match the phosphor composition. This mixture is fired at 800 ° C. to 1200 ° C. in air, and further fired at 1200 ° C. to 1400 ° C. in a mixed gas atmosphere containing hydrogen and nitrogen.

3-2, Configuration of Red Phosphor and Method for Producing the Same Next, the red phosphor material will be described. In the embodiment of the present invention, a red phosphor material containing at least one of (Y, Gd) (P, V) O ₄ : Eu phosphor or Y ₂ O ₃ : Eu phosphor as the red phosphor layer 14R. Is used. The red phosphor material (Y, Gd) (P, V) O ₄ : Eu phosphor or Y ₂ O ₃ : Eu phosphor is produced by the following method. Yttrium oxide (Y ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), vanadium oxide (V ₂ O ₅ ), phosphorus pentoxide (P ₂ O ₅ ) and europium oxide (EuO ₂ ) are matched to the phosphor composition. Mix like so. This mixture is fired at 600 ° C. to 800 ° C. in air, and further fired at 1000 ° C. to 1200 ° C. in a mixed gas atmosphere containing oxygen and nitrogen.

3-3, Green Phosphor and Manufacturing Method Therefor 3-3-1, Green Phosphor First, a green phosphor material will be described. In the embodiment of the present invention, as the green phosphor layer 14G, Zn ₂ SiO _4: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: green and a Ce A phosphor material is used.

Furthermore, in the present embodiment, the surface of the Zn ₂ SiO ₄ : Mn phosphor is covered with a two-layer metal oxide film. For example, the surface of the Zn ₂ SiO ₄ : Mn phosphor is coated with a metal oxide of magnesium oxide (MgO) as the first layer, and further the aluminum oxide is coated with magnesium oxide (MgO) as the second layer. ₂ The outermost surface of SiO ₄ : Mn is coated.

  The purpose of coating magnesium oxide (MgO) as the first layer is to improve the luminance of the PDP device and to suppress the luminance deterioration of the phosphor when the PDP device is used for a long time.

The purpose of coating the outermost surface with aluminum oxide as the second layer is that water (H ₂ O), carbon monoxide (CO), carbon dioxide (CO ₂ ), etc. brought into the PDP device by the first layer. It is to reduce the impure gas.

In particular, when magnesium oxide (MgO) is used as the coating material for the first layer, a large amount of impure gas is brought into the PDP device, and the driving voltage increases even if the luminance is improved. However, in addition to magnesium oxide (MgO) of the first layer, aluminum oxide (Al ₂ O ₃ ) is further coated on the outermost surface of Zn ₂ SiO ₄ : Mn as the second layer, so Carrying into the PDP device is reduced.

The impure gas brought into the PDP apparatus means that water (H ₂ O), carbon monoxide (CO), carbon dioxide (CO ₂ ), etc. adsorbed on the surface of the phosphor particles have passed through the manufacturing process of the PDP apparatus. It refers to the gas remaining on the phosphor particle surface.

_{Then, Zn 2 SiO 4: Zn 2} SiO 4 of aluminum oxide to be coated on the outermost surface of the Mn (Al ₂ O _3): Weight ratio of Mn is 100ppm or more 10000ppm or less. When it is less than 100 ppm, the effect of reducing impure gas brought into the PDP device is small. On the other hand, when it exceeds 10,000 ppm, the effect of shielding the excitation source of the phosphor by coating with aluminum oxide (Al ₂ O ₃ ) increases, and the luminance of the phosphor is impaired. Note that the first layer coating material is not limited to magnesium oxide (MgO) but includes metal oxides such as strontium oxide (SrO) and barium oxide (BaO). In this embodiment, magnesium oxide (MgO) is used for the first layer and aluminum oxide (Al ₂ O ₃ ) is used for the second layer, but aluminum oxide (Al ₂ O ₃ ) is not necessarily the second layer. It is sufficient that the outermost surface of the Zn ₂ SiO ₄ : Mn phosphor is covered with aluminum oxide. The method for coating the phosphor particles will be described in detail later.

3-3-2, Method for Producing Green Phosphor Next, a method for producing a green phosphor in the embodiment of the present invention will be described in detail. The Zn ₂ SiO ₄ : Mn phosphor is produced using a conventional solid phase reaction method, liquid phase method, or liquid spray method. The solid phase reaction method is a method in which an oxide or carbonate raw material and a flux are fired. The liquid phase method is a method in which a precursor of a phosphor material formed by hydrolyzing an organic metal salt or nitrate in an aqueous solution and adding an alkali or the like as necessary to precipitate is heat-treated.

Furthermore, the liquid spraying method is a method in which an aqueous solution containing a phosphor material is sprayed into a heated furnace. The Zn ₂ SiO ₄ : Mn phosphor used in the present embodiment is not particularly affected by the manufacturing method, but here, a manufacturing method by a solid phase reaction method will be described as an example.

First, the raw materials are mixed, and zinc oxide, silicon oxide, and manganese carbonate (MnCO ₃ ) are used as raw materials. In addition, as described above, manganese hydroxide, manganese nitrate, manganese halide, manganese oxalate and the like are used as initial materials in the same manner as in the method using manganese carbonate, and these are used as a firing step in the manufacturing process (to be described in detail later). ) To obtain manganese oxide indirectly. Further, manganese oxide may be used directly.

Zn ₂ SiO ₄ : High-purity (purity of 99% or more) zinc oxide is used as a material serving as a zinc supply source in Mn (hereinafter referred to as “Zn material”). Further, as described above, in addition to the method of directly using zinc oxide, high-purity (purity 99% or more) zinc hydroxide, zinc carbonate, zinc nitrate, zinc halide, zinc oxalate and the like are used as initial materials. A method of indirectly obtaining the zinc oxide by passing through a firing step (described in detail later) in the manufacturing process may be used.

As a material (hereinafter referred to as “Si material”) serving as a silicon supply source in Zn ₂ SiO ₄ : Mn, silicon dioxide having a high purity (purity 99% or more) can be used. Alternatively, a silicon hydroxide obtained by hydrolyzing a silicon alkoxide compound such as ethyl silicate may be used.

As an example of a specific green phosphor composition, 0.16 mol of MnCO ₃ , 1.80 mol of ZnO, and 1.00 mol of SiO ₂ are mixed. For mixing Mn material, Zn material and Si material, industrially used V-type mixers, stirrers, etc. can be used, and ball mills, vibration mills, jet mills etc. having a grinding function should also be used. Can do. As described above, a mixed powder of the green phosphor material is obtained.

  Next, the firing process will be described. The mixed powder of the phosphor material is heated in the air atmosphere to a maximum temperature of 1200 ° C. in about 6 hours after the start of baking, and this maximum temperature is maintained for baking for 4 hours. Thereafter, the temperature is lowered over a period of about 12 hours in a normal air atmosphere. Note that the atmosphere during firing is not limited to an air atmosphere, and may be a nitrogen atmosphere or a mixed atmosphere of nitrogen and hydrogen. The maximum temperature is preferably between 1100 ° C. and 1350 ° C., but there is no problem even if the maximum temperature maintenance time, temperature increase time, temperature decrease time, etc. are appropriately changed.

Next, (Y _1−x , Gd _x ) ₃ (Al _1−y , Ga _y ) ₅ O ₁₂ : Ce, which is the other green phosphor material, is produced by the following method. Yttrium oxide (Y ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), gallium oxide (Ga ₂ O ₃ ), and cerium oxide (CeO ₂ ) are adapted to the phosphor composition. To mix. The mixture is fired at 1000 ° C. to 1200 ° C. in air, and further fired at 1200 ° C. to 1400 ° C. in a mixed gas atmosphere containing oxygen and nitrogen. In the present embodiment, the composition is adjusted so that x = 0 and y = 0.2. However, if 0 ≦ x ≦ 1, 0 ≦ y ≦ 0.5, there is no problem with any composition. Absent.

Zn ₂ SiO ₄ : Mn thus produced and (Y _{1 -x} , Gd _x ) ₃ (Al _{1 -y} , Ga _y ) ₅ O ₁₂ : Ce are mixed to produce a green phosphor. In this embodiment, Zn ₂ SiO _4: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: was mixed Ce 50/50 by weight ratio, The mixing ratio needs to be adjusted as appropriate depending on the chromaticity design value and the phosphor particle diameter, and the same effect can be obtained regardless of the mixing ratio in terms of the driving voltage reduction effect.

3-3-3, Method of Coating Metal Oxide Surface of Green Phosphor Particles Next, a method of coating a metal oxide on the surface of phosphor particles of the green phosphor will be described. First, the case where an uncoated Zn ₂ SiO ₄ : Mn phosphor is coated with magnesium oxide (MgO) will be described. Magnesium nitrate is dissolved in water or an aqueous alkaline solution. An uncoated Zn ₂ SiO ₄ : Mn phosphor is put into the solution to prepare a mixed solution, which is stirred while being heated. When the heating temperature is less than 30 ° C., the metal salt is precipitated in the solution. At temperatures exceeding 60 ° C., the Zn ₂ SiO ₄ : Mn phosphor is dissolved by acid or alkali. For this reason, it heats and stirs within the temperature range of 30 degreeC or more and 60 degrees C or less. By this stirring, the magnesium cation in the solution is brought into close contact with the negatively chargeable Zn ₂ SiO ₄ : Mn phosphor to perform coating. The mixed solution is filtered and dried, and then the dried product is fired in air at 400 ° C. to 800 ° C. to complete a Zn ₂ SiO ₄ : Mn phosphor whose surface is coated with magnesium oxide (MgO). The coating amount of magnesium oxide (MgO) is determined by the amount of nitrate initially introduced. In addition, in the case of coating with other metal oxides, the surface of the phosphor particles of Zn ₂ SiO ₄ : Mn phosphor is similarly coated by appropriately changing the raw material nitrate and using the above method. be able to.

Next, the case where aluminum oxide (Al ₂ O ₃ ) is coated on the outermost surface of a Zn ₂ SiO ₄ : Mn phosphor coated with magnesium oxide (MgO) will be described. Aluminum nitrate is dissolved in water or an aqueous alkaline solution. An uncoated Zn ₂ SiO ₄ : Mn phosphor is put into the solution to prepare a mixed solution, which is stirred while being heated. When the heating temperature is less than 30 ° C., the metal salt is precipitated in the solution. At temperatures exceeding 60 ° C., the Zn ₂ SiO ₄ : Mn phosphor is dissolved by acid or alkali. For this reason, it heats and stirs within the temperature range of 30 degreeC or more and 60 degrees C or less. By this stirring, the aluminum cation in the solution is brought into close contact with the negatively chargeable Zn ₂ SiO ₄ : Mn phosphor to perform coating. This mixed solution is filtered and dried, and then the dried product is fired at 400 ° C. to 800 ° C. in the air, so that the outermost surface is coated with aluminum oxide (Al ₂ O ₃ ) Zn ₂ SiO ₄ : Mn phosphor Is completed. The coating amount of aluminum oxide (Al ₂ O ₃ ) is determined by the amount of nitrate initially introduced.

_4, Zn ₂ SiO 4 in the embodiment of the actual evaluation test results present invention: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: green phosphor layer containing Ce Table 1 shows the evaluation results of the actual PDP equipped with the above. In the present study evaluation, comparative and Example product of any Zn ₂ SiO _4: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: Ce a weight ratio 50% each.

4-1. Details of Comparative Product and Example Product Details of the comparative product 1 and the example product are as follows. The coating amount (ppm) of each metal oxide indicates the weight (wt%) of each metal oxide with respect to the weight (wt%) of the green phosphor powder in the manufacturing conditions.

<Comparative product 1>
Comparative product 1, Zn ₂ SiO ₄ with nothing coated on the surface of the phosphor particles: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: and a Ce It is a PDP provided with a configured phosphor layer.

<Example product 1>
The phosphor layers in the PDP of Example Product 1, the phosphor Zn ₂ SiO _4: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: a Ce, fluorescent The surface of the phosphor particles of the body Zn ₂ SiO ₄ : Mn is covered only with magnesium oxide (MgO). The coating amount of magnesium oxide (MgO) is 500 ppm.

<Example product 2>
The phosphor layers in the PDP of the embodiment product 2, the phosphor Zn ₂ SiO _4: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: a Ce, fluorescent The surface of the phosphor particles of the body Zn ₂ SiO ₄ : Mn is covered only with magnesium oxide (MgO). The coating amount of magnesium oxide (MgO) is 2500 ppm.

<Example product 3>
Example product 3 has phosphor particles of phosphor Zn ₂ SiO ₄ : Mn coated with magnesium oxide (MgO) and further oxidized on the outermost surface of Zn ₂ SiO ₄ : Mn coated with magnesium oxide (MgO). It is composed of a phosphor coated with aluminum (Al ₂ O ₃ ) as the second layer and (Y _1-x , Gd _x ) ₃ (Al _1-y , Ga _y ) ₅ O ₁₂ : Ce. A PDP provided with a phosphor layer. Magnesium oxide (MgO) is coated with 2500 ppm, and aluminum oxide (Al ₂ O ₃ ) is coated with 100 ppm.

<Example product 4>
Example product 4 has phosphor particles of phosphor Zn ₂ SiO ₄ : Mn coated with magnesium oxide (MgO) and further oxidized on the outermost surface of Zn ₂ SiO ₄ : Mn coated with magnesium oxide (MgO). It is composed of a phosphor coated with aluminum (Al ₂ O ₃ ) as the second layer and (Y _1-x , Gd _x ) ₃ (Al _1-y , Ga _y ) ₅ O ₁₂ : Ce. A PDP provided with a phosphor layer. Magnesium oxide (MgO) is coated with 2500 ppm, and aluminum oxide (Al ₂ O ₃ ) is coated with 1000 ppm.

<Example product 5>
Example product 5 has phosphor particles of phosphor Zn ₂ SiO ₄ : Mn coated with magnesium oxide (MgO) and further oxidized on the outermost surface of Zn ₂ SiO ₄ : Mn coated with magnesium oxide (MgO). It is composed of a phosphor coated with aluminum (Al ₂ O ₃ ) as the second layer and (Y _1-x , Gd _x ) ₃ (Al _1-y , Ga _y ) ₅ O ₁₂ : Ce. A PDP provided with a phosphor layer. Magnesium oxide (MgO) is coated with 2500 ppm, and aluminum oxide (Al ₂ O ₃ ) is coated with 10,000 ppm.

<Example product 6>
Example product 6 has phosphor particles of phosphor Zn ₂ SiO ₄ : Mn coated with magnesium oxide (MgO), and further oxidized on the outermost surface of Zn ₂ SiO ₄ : Mn coated with magnesium oxide (MgO). It is composed of a phosphor coated with aluminum (Al ₂ O ₃ ) as the second layer and (Y _1-x , Gd _x ) ₃ (Al _1-y , Ga _y ) ₅ O ₁₂ : Ce. A PDP provided with a phosphor layer. Magnesium oxide (MgO) is coated with 2500 ppm, and aluminum oxide (Al ₂ O ₃ ) is coated with 15000 ppm.

4-2, Evaluation of Actual Machines Table 1 shows powder luminance, gas fraction (%) by TDS analysis, and driving voltage in order to perform actual machine evaluations of Comparative Product 1 and Example Product 1 to Example Product 5. The result of variation (V) is shown.

4-2-1, Evaluation of Powder Luminance The brightness of each phosphor powder of Comparative Product 1 and Examples 1 to 6 was measured with a spectrophotometer (Hamamatsu Photonics, PMA- 12). The brightness in each example product is relatively represented when the brightness of the comparative product 1 is set to 100.

4-2-2, Evaluation of Adsorption Gas Amount In order to evaluate the amount of impure gas to the PDP device, the gas adsorption amount of the phosphor powder is evaluated by TDS thermal desorption gas spectroscopy (TDS). did. Electrochemical Co., Ltd. WA1000S / W was used for the measurement.

About the phosphor powder of the comparative product 1 and the example products 1 to 6, water (H ₂ O) and carbon monoxide desorbed from the phosphor powder when heated from 60 ° C. to 650 ° C. at 10 ° C./min. The total amount of (CO) and carbon dioxide (CO ₂ ) was measured. The amount of adsorbed gas in each example product relative to the amount of each gas in the comparative product 1 as 100 is shown relatively.

4-2-3, Characteristics of PDP In order to evaluate the fluctuation amount of the driving voltage caused by the impure gas brought into the PDP device by the oxide coated with the phosphor particles, the comparative product 1 and the example products 1 to 6 are The actually used PDP device was manufactured and the drive voltage was measured. The drive voltage is the lowest voltage value at which the PDP device is completely lit, the drive voltage in each example product is compared with the comparison product 1 with the drive voltage (V) of the comparison product 1 as a reference, and the drive voltage difference from the comparison product 1 (V) is shown. That is, if it is larger than the drive voltage (V) of the comparative product 1, it becomes a positive value, and if it is smaller, it becomes a negative value.

4-3. Results The results for each actual machine are shown in Table 1 below.

Regarding the brightness of the powder, when only the first layer of magnesium oxide (MgO) of Example products 1 and 2 was coated, when the coating amount of magnesium oxide (MgO) was 2500 ppm or less, there was a large change in the brightness of the phosphor. There is no problem in use as a PDP device. Further, when magnesium oxide (MgO) is coated as the first layer of Example products 3 to 6 and aluminum oxide (Al ₂ O ₃ ) is coated as the second layer, the coating amount of aluminum oxide (Al ₂ O ₃ ) is If it is 10000 ppm or less, there will be no big influence on the brightness | luminance of a fluorescent substance. However, when the coating amount of aluminum oxide (Al ₂ O ₃ ) exceeds 10,000 ppm, the aluminum oxide layer shields the ultraviolet rays that excite the phosphor, and the luminance is greatly reduced.

As for the amount of adsorbed gas, when only the first layer of magnesium oxide (MgO) is coated, water (H ₂ O) increases as the coating amount increases from Comparative Product 1 and Example Products 1 and _2. ), Carbon monoxide (CO) and carbon dioxide (CO ₂ ) have extremely large adsorption amounts, and especially at 2500 ppm, where the effect of luminance deterioration is high, water (H ₂ O) compared to when magnesium oxide (MgO) is not coated. ) Is about 1.4 times, carbon monoxide (CO) is about 1.3 times, and carbon dioxide (CO ₂ ) is about twice or more. On the other hand, as the second layer, Example products 3 to 5 in which the outermost surface of Zn ₂ SiO ₄ : Mn was coated with aluminum oxide (Al ₂ O ₃ ) at 100,1000,10000 ppm were water (H ₂ O), one Both carbon oxide (CO) and carbon dioxide (CO ₂ ) have a significantly small gas adsorption amount.

Further, the driving voltage as the PDP device is increased by 2.5 V in the example product 2 relative to the comparative product 1. On the other hand, in the example products 3 to 5 in which the outermost surface of Zn ₂ SiO ₄ : Mn is coated with aluminum oxide (Al ₂ O ₃ ) as the second layer, the comparative product 1 is 1.5V, 0.5V. The driving voltage is lower than that of Example Product 2 in which only the first layer is coated on the surface of Zn ₂ SiO ₄ : Mn at 0.5 V.

In particular, when the outermost surface of Zn ₂ SiO ₄ : Mn is coated with aluminum oxide (Al ₂ O ₃ ) in the range of 1000 ppm to 10,000 ppm as the second layer, the driving voltage difference is smaller.

From the above results, when the coating amount of the second layer of aluminum oxide (Al ₂ O ₃ ) is 100 ppm or more and 10000 ppm or less, a PDP device with a further reduced driving voltage can be realized.

5. Summary of Embodiments Characteristic portions in the above embodiment are listed below. In addition, the invention included in the said embodiment is not limited to the following. In addition, what was described in parentheses after each component is a specific example of each component. Each configuration is not limited to these specific examples.

(1)
The PDP device of the present invention has a front substrate (4) whose front side is transparent at least and a rear substrate (10) arranged to face each other via a discharge space (3), and partitions the discharge space (3) into a plurality of parts. The barrier ribs (13) are formed on the rear substrate (10), and an electrode group is formed on the front substrate (4) and the rear substrate (10) so that discharge occurs in the discharge space (15) partitioned by the barrier ribs (13). Is a plasma display device provided with a plasma display panel provided with a phosphor layer (14) that emits light by electric discharge, and Zn ₂ SiO ₄ : Mn and (Y _{1 -x} , Gd _x ) ₃ ( _{al 1-y, Ga y)} 5 O 12: Ce ( provided that, 0 ≦ x ≦ 1,0 ≦ y ≦ 0.5) green phosphor layer including a mixture of comprising a _{(14G), Zn 2 SiO 4} : Mn The surface of is coated with a metal oxide, and further a metal acid Zn ₂ SiO ₄ is coated with the object: the outermost surface of the Mn is characterized in that it is coated with aluminum oxide.

  As a result, it is possible to realize a PDP device with high luminance and high luminous efficiency that is driven at a lower voltage.

(2)
(1) The PDP apparatus is characterized in that the metal oxide is magnesium oxide.

  As a result, it is possible to realize a PDP device with high luminance and small luminance deterioration.

(3)
In the PDP apparatus of (1), the weight ratio of magnesium oxide is 2500 ppm or less with respect to Zn ₂ SiO ₄ : Mn.

  Accordingly, it is possible to realize a PDP device with higher luminance and less luminance deterioration.

(4)
In the PDP apparatus of (1), the weight ratio of aluminum oxide is 100 ppm to 10,000 ppm with respect to Zn ₂ SiO ₄ : Mn.

  Thereby, while maintaining a brightness | luminance, the impure gas brought in in a PDP apparatus is reduced. As a result, the drive voltage is reduced, a voltage margin can be secured and the light emission efficiency can be maintained, and a high-quality PDP device can be provided.

(5)
At least the front side has a transparent front substrate and a rear substrate disposed opposite to each other via a discharge space, and a partition wall for partitioning the discharge space is formed on the rear substrate, and discharge is performed in the discharge space partitioned by the partition wall. A method of manufacturing a plasma display device including a plasma display panel in which electrodes are arranged on a front substrate and a rear substrate so that a phosphor layer that emits light by discharge is provided, and Zn ₂ SiO ₄ : The surface of the green phosphor particles containing Mn is coated with a metal oxide, and the outermost surface of Zn ₂ SiO ₄ : Mn coated with the metal oxide is coated with aluminum oxide.

  As a result, it is possible to realize a PDP device with high luminance and high luminous efficiency that is driven at a lower voltage.

  INDUSTRIAL APPLICABILITY The present invention can realize a long-life, low power consumption, high-luminance PDP device, and is useful for a display device with a large screen.

DESCRIPTION OF SYMBOLS 1 Front plate 2 Back plate 3 Discharge space 4 Front substrate 5 Scan electrode 6 Sustain electrode 8 Dielectric layer 9 Protective layer 10 Rear substrate 11 Insulator layer 12 Data electrode 13 Partition 13a Vertical partition 13b Horizontal partition 14 Phosphor layer 14R Red fluorescence Body layer 14G Green phosphor layer 14B Blue phosphor layer 15 Discharge cell

Claims (5)

A discharge having a front substrate transparent at least on the front side and a rear substrate opposed to each other through a discharge space, and a partition for partitioning the discharge space into a plurality of partitions formed on the rear substrate, and partitioned by the partition A plasma display device comprising a plasma display panel in which an electrode group is arranged on the front substrate and the rear substrate so that a discharge occurs in space and a phosphor layer that emits light by discharge is provided,
The phosphor layer is Zn ₂ SiO _4: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: Ce ( provided that, 0 ≦ x ≦ 1,0 ≦ y ≦ 0 5), the surface of Zn ₂ SiO ₄ : Mn is coated with a metal oxide, and the outermost surface of Zn ₂ SiO ₄ : Mn is coated with the metal oxide. Is a plasma display device coated with aluminum oxide. The plasma display apparatus as claimed in claim 1, wherein the metal oxide is magnesium oxide. The weight ratio of the magnesium oxide is:
3. The plasma display device according to claim 2, wherein the content is 2500 ppm or less with respect to the Zn ₂ SiO ₄ : Mn. The weight ratio of the aluminum oxide is:
_2. The plasma display device according to claim 1, wherein the concentration is 100 ppm or more and 10,000 ppm or less with respect to the Zn ₂ SiO ₄ : Mn. A discharge having a front substrate transparent at least on the front side and a rear substrate opposed to each other through a discharge space, and a partition for partitioning the discharge space into a plurality of partitions formed on the rear substrate, and partitioned by the partition A method of manufacturing a plasma display device comprising a plasma display panel in which a group of electrodes is arranged on the front substrate and the rear substrate so that discharge occurs in space and a phosphor layer that emits light by discharge is provided,
The phosphor layer, Zn ₂ SiO _4: Mn and _{(Y 1-x, Gd x} ) 3 (Al 1-y, Ga y) 5 O 12: Ce ( provided that, 0 ≦ x ≦ 1,0 ≦ y ≦ 0.5) containing green phosphor particles,
The surface of the green phosphor particles containing Zn ₂ SiO ₄ : Mn is covered with a metal oxide, and the outermost surface of the Zn ₂ SiO ₄ : Mn covered with the metal oxide is covered with aluminum oxide. A method for manufacturing a plasma display device.

Images