JP4672231B2 - Plasma display panel - Google Patents

Description

【００９５】
サンプル１〜６は、赤色蛍光体に（Ｙ、Ｇｄ）_1-xＢＯ₃：Ｅｕ_x、緑色蛍光体にＺｎ_2-xＳｉＯ₄：Ｍｎ_x、青色蛍光体にＢａ_(1-x)Ｅｕ_xＭｇＡｌ_aＯ_bを用いた組み合わせのものであり、蛍光体の合成の方法、発光中心となるＥｕ、Ｍｎの置換比率、すなわちＹ、Ｂａ元素に対するＥｕの置換比率、およびＺｎ元素に対するＭｎの置換比率、および２価のＥｕイオンと置換する３価のＥｕイオン量を表１のように変化させたものである。また、サンプル７〜１１は、赤色蛍光体に（Ｙ、Ｇｄ）_1-xＢＯ₃：Ｅｕ_x、緑色蛍光体にＺｎ_2-xＳｉＯ₄：Ｍｎ_x、青色蛍光体にＢａ_(1-x-y)Ｅｕ_xＳｒ_yＭｇＡｌ_aＯ_bを用いた組み合わせのものであり、上記と同様、蛍光体合成方法の条件および発光中心の置換比率および青色蛍光体を構成するＢａあるいはＳｒのＥｕへの置換量（ｘ）やＡｌの量ａ、Ｏの量ｂ、および、２価のＥｕイオンと３価のＥｕイオンの量の比率を表１のように変化させたものである。
【００９６】
また、蛍光体層の形成に使用した蛍光体インキは、表１に示す各蛍光体粒子を使用して蛍光体、樹脂、溶剤、分散剤を混合して作製した。
【００９７】
そのときの蛍光体インキの粘度（２５℃）について測定した結果を、いずれも粘度が１５００〜３００００ＣＰの範囲に保たれている。形成された蛍光体層を観察したところ、いずれも隔壁壁面に均一に蛍光体インキが塗布され、しかも２００時間連続で目詰まりなく塗布できた。
【００９８】
また、各色における蛍光体層に使用される蛍光体粒子については、平均粒径０．１μｍ〜３．０μｍ、最大粒径８μｍ以下の粒径のものが各サンプルに使用されている。
【００９９】
サンプル１２は、Ｂａ_0.6Ｅｕ_0.1（Ｓｒ_0.3）ＭｇＡｌ₁₀Ｏ₁₇で、全てのＥｕが２価の青色蛍光体粒子を用いた。
【０１００】
サンプル１３は、Ｂａ_0.9Ｅｕ_0.1ＭｇＡｌ₁₄Ｏ₂₃の蛍光体で、Ｅｕの３価の割合が３０％の青色蛍光体粒子を用いた。
【０１０１】
サンプル１４は、Ｂａ_0.9Ｅｕ_0.1ＭｇＡ_19.4Ｏ_16.1の蛍光体で、全てのＥｕが２価の青色蛍光体粒子を用いた。
【０１０２】
サンプル１５は、Ｂａ_0.9Ｅｕ_0.1ＭｇＡ_19.4Ｏ_16.165の蛍光体で、Ｅｕの３価の割合が３０％の青色蛍光体粒子を用いた。
【０１０３】
なお、表１のＥｕイオンの２価、３価の測定は、ＸＡＮＥＳ（Ｘ−ｒａｙ Ａｂｓｏｒｐｔｉｏｎ Ｎｅａｒ Ｅｄｇｅ Ｓｔｒｕｃｔｕｒｅ）スペクトル法で測定した。
【０１０４】
（実験１）
作製されたサンプル１〜１１および比較サンプル１２〜１５について、背面パネル製造工程における蛍光体焼成工程（５２０℃，２０分）後、モデル的に１４７ｎｍの紫外光（ウシオ社製エキシマランプＨＤ００１２）を２００時間照射した際の青色蛍光体の輝度の変化率を測定した。
【０１０５】
（実験２）
パネルを各色に点燈した時の輝度及び青色蛍光体の輝度劣化変化率の測定は、ＰＤＰに電圧２００Ｖ、周波数１００ｋＨｚの放電維持パルスを５００時間連続して印加し、その前後におけるパネル輝度を測定し、そこから、（（印加後の輝度−印加前の輝度）／印加前の輝度）×１００により輝度劣化変化率を求めた。
【０１０６】
（実験３）
パネルの青色のみを全面点燈した時の輝度を、ＰＤＰの表示電極部分に電圧１８０Ｖ，周波数５０ｋＨｚを印加して測定した。
【０１０７】
また、ＰＤＰのアドレス放電時のアドレスミスについては画像を見てちらつきがあるかないかで判断し、１ヶ所でもあればありとしている。
【０１０８】
これら実験１〜３の青色蛍光体層部分の輝度および輝度劣化変化率についての結果を表２に示す。
【０１０９】
【表２】

【０１１０】
表２に示すように、比較サンプル１２〜１５において、Ｂａ_(1-x)Ｅｕ_xＭｇＡｌ_aＯ_b、あるいはＢａ_(1-x-y)Ｅｕ_xＳｒ_yＭｇＡｌ_aＯ_bの青色蛍光体において、ａの値が９．５０≦ａ≦９．９８の範囲外にあるサンプルは、１４７ｎｍの紫外線照射による劣化率が−４．５％〜−４１．５％と大きく、維持放電（２００Ｖ，１００ｋＨｚの維持放電パルス５００時間印加）における輝度劣化率も大きい。
【０１１１】
これに対して、実施例サンプル１〜１１については１４７ｎｍの紫外線照射による青色の変化率が全て２．８％以下の値で、維持放電パルス駆動中のパネルの劣化も少なくなっており、しかもアドレスミスもない。
【０１１２】
これは、青色蛍光体を構成するＡｌの量ａを９．５０≦ａ≦９．９８にすることによって、青色蛍光体中の酸素欠陥（特にＢａ−Ｏ近傍の酸素欠陥）が大幅に減少したためである。また、Ａｌのａの値を９．５０≦ａ≦９．９８とすることに加えて、Ｅｕの２価の一部を３価にすることによってもさらに紫外線による劣化が抑えられることもわかる。
【０１１３】
（実験４）
モデル実験として、青色蛍光体のＡｌの量ａの範囲を９．５０ａｔ％〜９．９８ａｔ％としたサンプル１〜１１は、上記の範囲であるサンプル（比較例１２〜１５）と比較して、６０℃９０％の相対湿度中に１０分間放置した後、１００℃で乾燥し、その後これらの蛍光体のＴＤＳ分析（昇温脱離ガス質量分析）を行った結果、水の物理吸着（１００℃付近）及び化学吸着（３００℃〜５００℃）のピークが１／１０以下であることが判った。
【０１１４】
【発明の効果】
以上のように本発明によれば、Ｂａを含有する層（Ｂａ−Ｏ層）近傍の酸素の欠陥をなくすことで、青色蛍光体表面への水の吸着を抑え、蛍光体の輝度劣化や色度変化、および放電特性の改善を行い、良好な画像表示が可能なＰＤＰを実現することができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態によるプラズマディスプレイパネルの前面ガラス基板を除いた平面図
【図２】本発明の一実施の形態によるプラズマディスプレイパネルの画像表示領域の構造の一部分を示す断面斜面図
【図３】本発明の一実施の形態によるプラズマディスプレイパネルを用いたプラズマディスプレイ装置のブロック図
【図４】本発明の一実施の形態によるプラズマディスプレイパネルの画像表示領域の構造を示す断面図
【図５】本発明の一実施の形態によるプラズマディスプレイパネルの蛍光体層を形成する際に用いるインキ塗布装置の概略構成図
【図６】本発明の一実施の形態による蛍光体の概略の原子構造を示す図
【符号の説明】
１００ ＰＤＰ
１０１ 前面ガラス基板
１０２ 背面ガラス基板
１０３ 表示電極
１０４ 表示スキャン電極
１０５ 誘電体ガラス層
１０６ ＭｇＯ保護層
１０７ アドレス電極
１０８ 誘電体ガラス層
１０９ 隔壁
１１０Ｒ 蛍光体層（赤）
１１０Ｇ 蛍光体層（緑）
１１０Ｂ 蛍光体層（青）
１２２ 放電空間
１２３ 放電セル[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma display panel having a phosphor layer that is used for image display such as a television and emits light when excited by ultraviolet rays.
[0002]
[Prior art]
2. Description of the Related Art In recent years, among color display devices used for image display such as computers and televisions, a plasma display device using a plasma display panel (hereinafter referred to as PDP) is a large, thin and light color display device that can be realized. Attention has been paid.
[0003]
The PDP performs full color display by additively mixing so-called three primary colors (red, green, and blue). In order to perform this full-color display, the PDP is provided with a phosphor layer that emits each of the three primary colors red (R), green (G), and blue (B), and the phosphor constituting the phosphor layer. The particles are excited by ultraviolet rays generated in the discharge cell of the PDP, and generate visible light of each color.
[0004]
Examples of the compound used in the phosphors of the above colors include (YGd) BO that emits red light._Three: Eu³⁺, Y₂O_Three: Eu³⁺Zn that emits green light₂SiO_Four: Mn²⁺BaMgAl emitting blue light_TenO₁₇: Eu²⁺It has been known. Each of these phosphors is prepared by mixing a predetermined raw material and then performing a solid phase reaction by firing at a high temperature of 1000 ° C. or higher (see, for example, phosphor handbook P219, 225 Ohm). The phosphor particles obtained by this firing are used after being crushed and sieved (red and green average particle diameters: 2 μm to 5 μm, blue average particle diameters: 3 μm to 10 μm).
[0005]
The reason for pulverizing and sieving (classifying) the phosphor particles is that, in general, when forming a phosphor layer on a PDP, a screen printing method using each color phosphor particle as a paste, or an ink that ejects phosphor ink from a thin nozzle This is because a jet method or the like is used, and when the paste is applied, the phosphor has a smaller particle size and is more uniform (having a uniform particle size distribution), so that a cleaner application surface can be easily obtained. In other words, the smaller and more uniform the particle size of the phosphor is, the closer the shape is to a spherical shape, the cleaner the coating surface, the higher the packing density of the phosphor particles in the phosphor layer, and the larger the light emitting surface area of the particles. This is because time instability is also improved, and as a result, it is theoretically considered that the brightness of the PDP can be increased.
[0006]
[Problems to be solved by the invention]
However, reducing the particle size of the phosphor particles increases the surface area of the phosphor and at the same time increases the defects in the phosphor. Therefore, a lot of water, carbon dioxide gas, or hydrocarbon-based organic matter is likely to adhere to the phosphor surface. In particular, the conventional Ba_1-xMgAl₁₄O_{twenty three}: Eu_xAnd Ba_1-xMgAl_TenO₁₇: Eu_xAnd Ba_1-xySr_yMgAl_TenO₁₇: Eu_xIn the case of a blue phosphor having a divalent Eu ion as the emission center (0.02 ≦ x ≦ 0.2, 0.1 ≦ y ≦ 0.5), these crystal structures are layered It has a structure (for example, display and imaging 1999, vol. 7, pp225-234), and oxygen (O) in the vicinity of the layer containing Ba atoms (Ba-O layer) exists in the layer. In particular, there is a problem that the amount of defects increases further when the particle size is reduced (for example, Applied Physics, Vol. 70, No. 3, 2001, pp310). Then, water present in the air is selectively adsorbed to oxygen vacancies in the vicinity of the Ba—O layer of the phosphor, and the adsorbed water reacts with ultraviolet rays (wavelength 174 nm) generated in the panel. In other words, problems such as lowering of the brightness of the panel and changes in chromaticity (color shift due to chromaticity change and screen burning) occur.
[0007]
In particular, as in the conventional blue phosphor described above, β-alumina having a Al content of 10 to 14 atomic% (at%) or more and a blue phosphor having a magnetoplumbite structure have a Ba—O layer during the phosphor manufacturing process. There was a problem that oxygen defects were likely to occur in the vicinity.
[0008]
Conventionally, in order to solve these problems, Al is applied to the phosphor surface for the purpose of repairing oxygen defects.₂O_ThreeA method of coating the entire surface with a crystal has been devised (for example, JP-A-2001-55567). However, there has been a problem that by coating the entire surface, ultraviolet light is absorbed and the emission luminance of the phosphor is lowered, and even when coated, the luminance is still lowered by ultraviolet light.
[0009]
The present invention has been made in view of such a problem. By eliminating oxygen defects in the vicinity of the Ba-containing layer (Ba-O layer) in the phosphor and suppressing the adsorption of water to the blue phosphor surface, An object of the present invention is to realize a PDP capable of improving the luminance deterioration and chromaticity change of a phosphor and capable of displaying a good image.
[0010]
[Means for Solving the Problems]
  In order to achieve the above object, the plasma display panel of the present invention provides:A plasma display panel in which a plurality of discharge cells of one color or a plurality of colors are arranged and a phosphor layer of a color corresponding to each discharge cell is disposed, wherein the phosphor layer has a blue phosphor layer, This blue phosphor layer is composed of Ba _(1-x) Eu _x MgAl _a O _b Or Ba _(1-xy) Eu _x Sr _y MgAl _a O _b And is 0.02 ≦ x ≦ 0.2, 0.1 ≦ y ≦ 0.5, 9.50 ≦ a ≦ 9.98, 16.25 ≦ b ≦ 16.995 In addition, by firing at 700 ° C. to 1000 ° C. in an oxidizing atmosphere, among the Eu ions, the divalent one is 30% to 90%, the trivalent one is 10% to 70%, and the average particle diameter Is formed by using a blue phosphor having a thickness of 0.1 μm to 3.0 μm.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
By the way, phosphors used for PDPs and the like are produced by various methods. In any of these methods, defects are likely to occur when the particle diameter is reduced. In particular, when a phosphor is produced by a solid phase reaction method, it is known that many defects are generated in the phosphor because it is fired or pulverized in a reducing atmosphere.
[0016]
Further, it is also known that a defect is generated in the phosphor even by ultraviolet rays having a wavelength of 147 nm generated by discharge when driving the panel (for example, EID99-94 20001). May 27).
[0017]
Furthermore, Ba, which is a blue phosphor_1-xMgAl_TenO₁₇: Eu_xAnd Ba_1-xMgAl₁₃O_{twenty four}: Eu_xIt is also known that a phosphor having an Al content of 10 at% or more has an oxygen defect (particularly an Al—O layer adjacent to the Ba—O layer) in the phosphor itself (for example, applied physics, 70, No. 3, 2001, PP310). FIG. 6 shows BaMgAl_TenO₁₇: It is the figure which showed typically the structure of Ba-O layer vicinity of Eu blue fluorescent substance.
[0018]
Conventionally, it has been considered that the occurrence of these defects itself is a cause of luminance deterioration of the blue phosphor.
[0019]
However, as a result of the studies conducted by the present inventors, the essence of the cause of luminance deterioration is not only the existence of defects, but also water and carbon dioxide gas are selectively adsorbed to oxygen (O) defects near the Ba-O layer. The present inventors have found that the phosphor reacts with water and carbon dioxide gas when the adsorbed state is irradiated with ultraviolet rays or ions. That is, various deteriorations such as luminance deterioration and color shift are caused by water and carbon dioxide gas adsorbing to oxygen defects (Ba-O layer and adjacent Al-O layer) near the Ba-O layer in the blue phosphor. I got the knowledge that happens.
[0020]
Based on the above knowledge, the present invention is intended to prevent deterioration such as a decrease in luminance of the blue phosphor by reducing oxygen defects in the vicinity of the Ba—O layer in the blue phosphor.
[0026]
Here, when the amount a of Al in the crystal is less than 10 at% of the stoichiometric amount, for example, when the amount of Al is 9.9 at%, + trivalent Al is slightly reduced. At this time, -2 O is reduced from 17 at% to 16.85% in order to maintain the neutrality of the charge of the entire crystal. Therefore, the ratio of O / Al is 16.85 / 9.9 = 1.702. In the case of the stoichiometric crystal, +3 valent Al is 10 at%, -2 valent O is 17 at%, and the O / Al ratio is 1.7. The ratio of O increases compared to the case, which is considered to compensate for oxygen defects in the vicinity of the Ba-O layer.
[0027]
The amount of Al is preferably 9.50 at% to 9.98 at%. This is because a single β-alumina crystal phase is difficult to be formed at 9.50 at% or less, so that the improvement effect is small, and at 9.98 at% or more, the oxygen compensation effect is small, resulting in a decrease in luminance due to ultraviolet rays. It is.
[0028]
Further, the amount a of Al and the amount b of O subordinate thereto are stoichiometric (for example, a = 10, B = 17), and Ba, Eu, and Sr are similar to the molar ratio of the conventional phosphor. In some cases (for example, 0.02 ≦ x ≦ 0.2, 0.1 ≦ y ≦ 0.5), the phosphor is baked in an oxidizing atmosphere, and some of the Eu divalent ions are Substituting with trivalent Eu ions significantly increases the positive charge in the crystal. This is because Ba, Sr, and Eu were all divalent, but trivalent Eu was increased in the crystal, particularly in the Ba-O layer, due to oxidation of Eu. Then, in order to neutralize (compensate for) this greatly increased + charge, oxygen defects (O) in the vicinity of the Ba element are filled with -charged oxygen (O), resulting in oxygen in the vicinity of the Ba-O layer. Defects are believed to be reduced.
[0029]
The ratio of divalent Eu and trivalent Eu in Eu ions is preferably 30% to 90% for divalent Eu and 10% to 70% for trivalent Eu. This is because when the amount of substitution from divalent Eu to trivalent Eu is 10% or less, the effect of compensating oxygen is somewhat small, and when it is 70% or more, the luminance of the phosphor is lowered, which is not preferable.
[0030]
In addition, the phosphor particles having a trivalent Eu ion of 10% to 70% have a small particle size of 0.05 μm to 3 μm and a good particle size distribution. Thus, if the phosphor layer is formed using this phosphor particle, the packing density is improved, and the emission area of the phosphor particle that substantially contributes to light emission is increased, so that the luminance can be improved. it can.
[0031]
Here, phosphors can be produced by hydrolyzing these in an aqueous solution using a solid-phase reaction method using conventional oxides and carbonates, or a raw material and a flux of nitrate, or an organic metal salt or nitrate. Alternatively, a phosphor precursor is prepared using a coprecipitation method in which alkali or the like is added for precipitation, and then this is heat-treated, or an aqueous solution containing the phosphor raw material is sprayed into a heated furnace. There are various manufacturing methods such as a liquid spray method to be manufactured by using any of the phosphors prepared by any method._(1-x)Eu_xMgAl_aO_bOr Ba_(1-xy)Eu_xSr_yMgAl_aO_bThe amount of Al element in the steel is 10 at% or less, particularly 9.50 to 9.98, or Eu ions are 30% to 90% for divalent and 10% to 70% for trivalent. It has been confirmed that the above-mentioned effects are similarly obtained by performing both or both.
[0032]
Here, the amount a of Al is changed from 10 to 9.50 to 9.98, and the Eu ion is changed from 30% to 90% for the divalent and from 10% to 70% for the trivalent. The above-mentioned effect can be obtained by satisfying only one, but preferably the effect is further increased if both are satisfied.
[0033]
Here, an example of a method for manufacturing the phosphor will be described. First, it is a manufacturing method by a solid phase reaction method._Three, MgCO_Three, Al₂O_Three, Eu₂O_ThreeCarbon dioxide or oxide such as, and flux (AlF as a sintering accelerator if necessary)_Three, NH_FourCl) and baked at 1000 ° C. to 1400 ° C. for 2 hours, and then pulverized and sieved. And then at 1500 ° C. for 2 hours in a reducing atmosphere (H₂N containing 5%₂Medium) and pulverization and sieving again to obtain a phosphor.
[0034]
Or in addition, the phosphor may be oxygen (O₂), Oxygen-nitrogen (N₂) Or ozone (O_Three)-Firing in an oxidizing atmosphere in nitrogen at 700 ° C to 1000 ° C to replace a part of divalent Eu with trivalent.
[0035]
In the case of a liquid phase method for producing a phosphor from an aqueous solution, first, an organometallic salt (for example, alkoxide or acetylacetone) containing an element constituting the phosphor or nitrate is dissolved in water and then hydrolyzed. A coprecipitate (hydrate) is prepared, and the powder obtained by hydrothermal synthesis (crystallization in an autoclave), firing in air, or spraying in a high-temperature furnace is 1000 ° C to 1400 ° C. For 2 hours in a reducing atmosphere (H₂N containing 5%₂B) and pulverize and screen.
[0036]
Or in addition, O₂, O₂-N₂, O_Three-N₂In an oxidizing atmosphere such as 700 ° C. to 1000 ° C., a part of divalent Eu is replaced with trivalent.
[0037]
Here, the baking in the oxidizing atmosphere described above may be performed between 1000 ° C. and 700 ° C. when the temperature is lowered in the same furnace after the reduction step at 1000 ° C. to 1400 ° C.
[0038]
Further, the fact that a part of the divalent Eu ion has become trivalent can be identified by measuring an XANES (X-ray Absorption Near Edge Structure) spectrum.
[0039]
As described above, according to the present invention, oxygen defects near the Ba-containing layer (Ba-O layer) in the phosphor are eliminated, and water adsorption on the surface of the blue phosphor is suppressed. A phosphor capable of improving luminance deterioration and chromaticity change can be realized. The plasma display using such a phosphor enables a plasma display capable of displaying a good image.
[0040]
  That is, the plasma display panel according to the present invention isA plasma display panel in which a plurality of discharge cells of one color or a plurality of colors are arranged and a phosphor layer of a color corresponding to each discharge cell is disposed, wherein the phosphor layer has a blue phosphor layer, This blue phosphor layer is composed of Ba _(1-x) Eu _x MgAl _a O _b Or Ba _(1-xy) Eu _x Sr _y MgAl _a O _b And is 0.02 ≦ x ≦ 0.2, 0.1 ≦ y ≦ 0.5, 9.50 ≦ a ≦ 9.98, 16.25 ≦ b ≦ 16.995 In addition, by firing at 700 ° C. to 1000 ° C. in an oxidizing atmosphere, among the Eu ions, the divalent one is 30% to 90%, the trivalent one is 10% to 70%, and the average particle diameter Formed using a blue phosphor having a thickness of 0.1 μm to 3.0 μmIt is characterized by this.
[0043]
Here, as specific phosphor particles used for the red phosphor layer of the plasma display panel, Y_2xO_Three: Eu_xOr (Y, Gd)_1-xBO_Three: Eu_xThe compound represented by these can be mentioned. Here, if the value of x in the compound of the red phosphor is 0.05 ≦ x ≦ 0.20, it is excellent in luminance and luminance deterioration.
[0044]
Specific phosphor particles used for the green phosphor layer of the plasma display panel include Ba_1-xAl₁₂O₁₉: Mn_xOr Zn_2-xSiO_Four: Mn_xThe compound represented by these can be mentioned. Here, the value of X in the compound of the green phosphor is preferably 0.01 ≦ x ≦ 0.10 because it is excellent in luminance and luminance deterioration.
[0045]
In addition, the average particle diameter of each phosphor particle of blue, red, and green is preferably in the range of 0.1 μm to 3.0 μm. The particle size distribution is more preferably such that the maximum particle size is 4 times or less of the average value and the minimum value is 1/4 or more of the average value. The region where the ultraviolet rays reach in the phosphor particles is as shallow as about several hundred nm from the particle surface, and almost only the surface emits light. If the particle size of such phosphor particles is 3.0 μm or less, the particles that contribute to light emission As the surface area of the phosphor layer increases, the luminous efficiency of the phosphor layer is kept high. On the other hand, if the thickness is 3.0 μm or more, the phosphor needs to have a thickness of 20 μm or more, and a sufficient discharge space cannot be secured. If the thickness is 0.1 μm or less, defects are likely to occur and the luminance is not improved.
[0046]
Moreover, if the thickness of the phosphor layer is within a range of 8 to 25 times the average particle diameter of the phosphor particles, a sufficient discharge space can be secured while maintaining a high luminous efficiency of the phosphor layer. The brightness in the PDP can be increased. In particular, when the average particle diameter of the phosphor is 3 μm or less, the effect is large (Image Information Society of Japan IDY2000-317.PP32).
[0047]
The plasma display panel according to the present invention is manufactured by a manufacturing method including a step of forming a phosphor layer using the blue phosphor particles of the present invention between the partition walls of the front plate. Thereby, a plasma display panel excellent in luminance and luminance deterioration can be obtained.
[0048]
The phosphor according to the present invention can also be applied to a fluorescent lamp. Thereby, it can be set as the fluorescent lamp which fluorescent substance particle itself is excellent in the light emission characteristic, and was excellent in the brightness | luminance and brightness degradation.
[0049]
Hereinafter, a PDP according to an embodiment of the present invention will be described with reference to the drawings.
[0050]
FIG. 1 is a schematic plan view of the PDP with the front glass substrate removed, and FIG. 2 is a perspective view showing a part of the image display area of the PDP in cross section. In FIG. 1, the number of display electrode groups, display scan electrode groups, address electrode groups, and the like are partially omitted for easy understanding.
[0051]
As shown in FIG. 1, a PDP 100 includes a front glass substrate 101 (not shown), a rear glass substrate 102, N display electrodes 103 (i) (i = 1 to N), and N displays. The scan electrode 104 group (i) (i = 1 to N), the M address electrode 107 group (j) (j = 1 to M), and the hermetic seal layer 121 indicated by oblique lines, A discharge cell 123 is formed at the intersection of the display electrode 103, the display scan electrode 104, and the address electrode 107. Further, the discharge cells 123 gather to form an image display area 124.
[0052]
As shown in FIG. 2, the PDP 100 includes a front panel in which a display electrode 103, a display scan electrode 104, a dielectric glass layer 105, and an MgO protective layer 106 are disposed on one main surface of a front glass substrate 101; A rear panel on which the address electrode 107, the dielectric glass layer 108, the barrier rib 109, and the phosphor layers 110R, 110G, and 110B are disposed on one main surface of the glass substrate 102 is bonded to the front panel and the rear panel. A discharge gas is enclosed in a discharge space 122 formed therebetween, and a plasma display device is configured by connecting to a PDP driving device shown in FIG.
[0053]
As shown in FIG. 3, the plasma display device includes a display driver circuit 153, a display scan driver circuit 154, and an address driver circuit 155 in the PDP 100, and display scan electrodes in a cell to be lit under the control of the controller 152. A voltage is applied to the address electrode 107 and the address electrode 107 to perform an address discharge therebetween, and then a pulse voltage is applied between the display electrode 103 and the display scan electrode 104 to perform a sustain discharge. By this sustain discharge, ultraviolet light is generated in the cell, and the phosphor layer excited by the ultraviolet light emits light to light the cell. An image is displayed by a combination of lighting and non-lighting of each color cell.
[0054]
Next, a manufacturing method of the above-described PDP will be described with reference to FIGS.
[0055]
The front panel is formed on the front glass substrate 101 by first forming each of the N display electrodes 103 and the display scan electrodes 104 (only two of them are shown in FIG. 2) in a stripe shape alternately and in parallel. The dielectric glass layer 105 is coated from above, and the MgO protective layer 106 is formed on the surface of the dielectric glass layer 105.
[0056]
The display electrode 103 and the display scan electrode 104 are electrodes composed of a transparent electrode made of ITO and a bus electrode made of silver, and the silver paste for the bus electrode is formed by applying it by screen printing and baking it. Is done.
[0057]
The dielectric glass layer 105 is coated with a paste containing a lead-based glass material by screen printing, and then baked at a predetermined temperature for a predetermined time (for example, 560 ° C. for 20 minutes) to thereby obtain a predetermined layer thickness (about 20 μm). It forms so that it becomes. Examples of the paste containing the lead-based glass material include PbO (70 wt%), B₂O_Three(15 wt%), SiO₂(10 wt%) and Al₂O_ThreeA mixture of (5 wt%) and an organic binder (10% ethyl cellulose dissolved in α-terpineol) is used. Here, the organic binder is obtained by dissolving a resin in an organic solvent. In addition to ethyl cellulose, an acrylic resin can be used as the resin, and butyl carbitol can be used as the organic solvent. Furthermore, you may mix a dispersing agent (for example, glyceryl trioleate) in such an organic binder.
[0058]
The MgO protective layer 106 is made of magnesium oxide (MgO), and is formed to have a predetermined thickness (about 0.5 μm) by, for example, a sputtering method or a CVD method (chemical vapor deposition method).
[0059]
On the other hand, the rear panel is formed in such a manner that M address electrodes 107 are arranged in a row by first forming a silver paste for electrodes on the rear glass substrate 102 by screen printing or photography, and then firing it. Is done. After that, a paste containing a lead-based glass material is applied by a screen printing method to form a dielectric glass layer 108. After the same paste containing a lead-based glass material is repeatedly applied at a predetermined pitch by a screen printing method, A partition wall 109 is formed by firing. By the barrier ribs 109, the discharge space 122 is partitioned for each cell (unit light emitting region) in the line direction.
[0060]
FIG. 4 is a partial cross-sectional view of the PDP 100. As shown in FIG. 4, the gap dimension W of the partition wall 109 is defined to be about 130 μm to 240 μm according to the HD-TV having a constant value of 32 inches to 50 inches.
[0061]
In the groove between the barrier ribs 109, a red (R) phosphor material, a green (G) phosphor material, and Ba_(1-x)Eu_xMgAl_aO_bOr Ba_(1-xy)Eu_xSr_yMgAl_aO_bA blue structure having a crystal structure of 0.02 ≦ x ≦ 0.2, 0.1 ≦ y ≦ 0.5, 9.50 ≦ a ≦ 9.98, 16.25 ≦ b ≦ 16.995 B) Phosphor material or Ba_(1-x)Eu_xMgAl_aO_bOr Ba_(1-xy)Eu_xSr_yMgAl_aO_bA blue (B) phosphor material having a crystal structure of 10% to 70% of divalent Eu ions and 10% to 70% of trivalent Eu ions, or Ba_(1-x)Eu_xMgAl_aO_bOr Ba_(1-xy)Eu_xSr_yMgAl_aO_bAnd 0.02 ≦ x ≦ 0.2, 0.1 ≦ y ≦ 0.5, 9.50 ≦ a ≦ 9.98, 16.25 ≦ b ≦ 16.995, and Apply paste-like phosphor ink consisting of each of the blue (B) phosphor materials with 30% to 90% divalent Eu ions and 10% to 70% trivalent Eu ions and an organic binder. Then, this is baked at a temperature of 400 to 590 ° C. to burn off the organic binder, thereby forming phosphor layers 110R, 110G, and 110B in which the phosphor material particles are bound. The thickness L in the stacking direction of the phosphor layers 110R, 110G, and 110B on the address electrode 107 is preferably about 8 to 25 times the average particle diameter of the color phosphor particles. That is, in order to ensure the brightness (luminous efficiency) when the phosphor layer is irradiated with a certain ultraviolet ray, the phosphor layer absorbs the ultraviolet ray generated in the discharge space without transmitting it, so that the phosphor particles are at a minimum. However, it is desirable to maintain a thickness of 8 layers, preferably 20 layers. If the thickness is greater than that, the luminous efficiency of the phosphor layer is almost saturated, and if the thickness exceeds about 20 layers, the size of the discharge space 122 cannot be sufficiently secured. In addition, if the particle size is sufficiently small and spherical, such as phosphor particles obtained by a hydrothermal synthesis method, etc., even if the number of stacked layers is the same as when non-spherical particles are used, As the body layer filling degree increases and the total surface area of the phosphor particles increases, the phosphor particle surface area contributing to actual light emission in the phosphor layer increases, and the luminous efficiency is further increased, which is preferable. Eu ions used in the method for synthesizing the phosphor layers 110R, 110G, and 110B and the blue phosphor layer are 30% to 90% of divalent, and 10% to 70% of trivalent. A method for producing the blue phosphor will be described later.
[0062]
The front plate and the back plate produced as described above are overlaid so that each electrode of the front plate and the address electrode of the back plate are orthogonal to each other, and a sealing glass is disposed on the peripheral edge of the panel, It seals by baking at about 450 degreeC for 10 to 20 minutes, and forming the airtight seal layer 121 (FIG. 1). Then, once the inside of the discharge space 122 is in a high vacuum (eg, 1.1 × 10 6^-FourAfter exhausting to Pa), the PDP 100 is completed by enclosing a discharge gas (for example, He—Xe-based or Ne—Xe-based inert gas) at a predetermined pressure.
[0063]
FIG. 5 is a schematic configuration diagram of an ink coating apparatus used when forming the phosphor layer.
As shown in FIG. 5, the ink coating apparatus 200 includes a server 210, a pressure pump 220, a header 230, and the like, and the phosphor ink supplied from the server 210 that stores the phosphor ink is sent from the header 230 by the pressure pump 220. Is supplied under pressure. The header 230 is provided with an ink chamber 230a and a nozzle 240 (with an inner diameter of 30 μm to 120 μm), and the phosphor ink pressurized and supplied to the ink chamber 230a is continuously discharged from the nozzle 240. It has become. The diameter D of the nozzle 240 is desirably 30 μm or more for preventing clogging of the nozzle and not more than an interval W (about 130 μm to 200 μm) between the partition walls 109 for preventing protrusion from the partition wall during coating. Usually, it is set to 30 μm to 130 μm.
[0064]
The header 230 is configured to be linearly driven by a header scanning mechanism (not shown). By scanning the header 230 and continuously ejecting the phosphor ink 250 from the nozzle 240, the header 230 is placed on the rear glass substrate 102. The phosphor ink is uniformly applied to the grooves between the barrier ribs 109. Here, the viscosity of the phosphor ink used is kept in the range of 1500 to 30000 CP (centipoise) at 25 ° C.
[0065]
The server 210 is provided with a stirring device (not shown), and the stirring prevents the precipitation of particles in the phosphor ink. The header 230 is integrally formed including the ink chamber 230a and the nozzle 240, and is manufactured by machine processing and electric discharge processing of a metal material.
[0066]
The method of forming the phosphor layer is not limited to the above method, and various methods such as a photolithographic method, a screen printing method, and a method of arranging a film in which phosphor particles are mixed are used. Can be used.
[0067]
The phosphor ink is prepared by mixing phosphor particles of various colors, a binder, and a solvent so as to be 1500 to 30000 centipoise (CP). If necessary, a surfactant, silica, a dispersant ( 0.1 to 5 wt%) may be added.
[0068]
Here, as a blue phosphor used when being prepared as a blue phosphor ink, Ba_(1-x)Eu_xMgAl_aO_bOr Ba_(1-xy)Eu_xSr_yMgAl_aO_bA blue structure having a crystal structure of 0.02 ≦ x ≦ 0.2, 0.1 ≦ y ≦ 0.5, 9.50 ≦ a ≦ 9.98, 16.25 ≦ b ≦ 16.995 B) phosphor and Ba_(1-x)Eu_xMgAl_aO_bOr Ba_(1-xy)Eu_xSr_yMgAl_aO_bAnd 0.02 ≦ x ≦ 0.2, 0.1 ≦ y ≦ 0.5, 9.50 ≦ a ≦ 9.98, 16.25 ≦ b ≦ 16.995, and A blue (B) phosphor in which Eu ions are 30% to 90% for divalent and 10% to 70% for trivalent, and Ba_(1-x)Eu_xMgAl_aO_bOr Ba_(1-xy)Eu_xSr_yMgAl_aO_bThe blue (B) phosphor has a crystal structure of 2%, and Eu ions are 30% to 90% divalent and 10% to 70% trivalent.
[0069]
In addition, as a red phosphor used when being prepared as a red phosphor ink, (Y, Gd)_1-xBO_Three: Eu_xOr Y_2xO_Three: Eu_xThe compound represented by these is mentioned. These are compounds in which part of the Y element constituting the base material is substituted with Eu. Here, the substitution amount X of the Eu element with respect to the Y element is preferably in the range of 0.05 ≦ x ≦ 0.20. If the substitution amount is larger than this, the luminance is increased, but the luminance is significantly deteriorated. On the other hand, when the amount is less than this substitution amount, the composition ratio of Eu, which is the emission center, is lowered, the luminance is lowered, and the phosphor cannot be used.
[0070]
In addition, as a green phosphor used when being prepared as a green phosphor ink, Ba_1-xAl₁₂O₁₉: Mn_xOr Zn_2-xSiO_Four: Mn_xThe compound represented by these is mentioned. Ba_1-xAl₁₂O₁₉: Mn_xIs a compound in which a part of the Ba element constituting the base material is substituted with Mn, and Zn_2-xSiO_Four: Mn_xIs a compound in which a part of Zn element constituting the base material is substituted with Mn. Here, the substitution amount x of the Mn element with respect to the Ba element and the Zn element is preferably in the range of 0.01 ≦ x ≦ 0.10 for the same reason as described for the red phosphor.
[0071]
Ethyl cellulose or acrylic resin can be used as the binder to be prepared for the phosphor ink (mixed with 0.1 to 10 wt% of the ink), and α-terpineol or butyl carbitol can be used as the solvent. A polymer such as PMA or PVA can be used as the binder, and an organic solvent such as diethylene glycol or methyl ether can be used as the solvent.
[0072]
The method for producing the phosphor particles may be any of a solid phase reaction method, a liquid phase method, a liquid spray method, a hydrothermal synthesis method and the like, and is not particularly limited.
[0073]
(1) Blue phosphor
(Ba_(1-x)Eu_xMgAl_aO_babout)
First, barium nitrate Ba (NO, which is a raw material in the mixed liquid preparation step)_Three)₂, Magnesium nitrate Mg (NO_Three)₂, Aluminum nitrate Al (NO_Three)_Three, Europium nitrate Eu (NO_Three)₂Are mixed so that the molar ratios are 0.02 ≦ x ≦ 0.30, 9.50 ≦ a ≦ 9.98, 16.50 ≦ b ≦ 16.95, and this is dissolved in an aqueous medium and mixed. Make a liquid. In this aqueous medium, ion-exchanged water and pure water are preferable in that they do not contain impurities, but they can be used even if they contain a non-aqueous solvent (such as methanol or ethanol).
[0074]
Next, this mixed liquid is put in a container having corrosion resistance and heat resistance such as gold or platinum, and is heated in a high pressure container at a predetermined temperature (100, for example) using an apparatus such as an autoclave. To 300 ° C) and hydrothermal synthesis (12 to 20 hours) under a predetermined pressure (0.2 MPa to 10 MPa) to form powder.
[0075]
Next, the powder is fired in a reducing atmosphere (for example, an atmosphere containing 5% hydrogen and 95% nitrogen) at a predetermined temperature for a predetermined time (for example, 1350 ° C. for 2 hours), and then classified. A phosphor is prepared.
[0076]
Or in addition, this phosphor₂, O₂-N₂Or O_Three-N₂By baking in an oxidizing atmosphere such as 700 ° C. to 1000 ° C., the divalent Eu in the blue phosphor produced in the reducing atmosphere (Eu of the blue phosphor produced in the reducing atmosphere is mostly divalent) Is replaced with trivalent Eu.
[0077]
Here, the phosphor particles obtained by hydrothermal synthesis are likely to be spherical in shape, and the particle size is smaller than that produced by the solid phase reaction method (average particle size: 0.05 μm to About 2.0 μm). The term “spherical” used herein is defined so that the axial diameter ratio (short axis diameter / major axis diameter) of most fluorescent particles is, for example, 0.9 or more and 1.0 or less. However, not all of the phosphor particles need be within this range.
[0078]
In the above description, a blue phosphor obtained by a liquid spray method in which a phosphor is synthesized by spraying a mixed solution from a nozzle to a high-temperature furnace without putting it in a gold or platinum container, or, further, O₂, O₂-N₂Or O_Three-N₂A phosphor having the same effect can be obtained even if it is baked.
[0079]
(Ba_(1-xy)Eu_xSr_yMgAl_aO_babout)
This phosphor is the Ba described above._(1-x)Eu_xMgAl_aO_bBa is partially substituted with Sr, and is produced by a solid phase reaction method. The method will be described below.
[0080]
As raw material, barium hydroxide Ba (OH)₂, Strontium hydroxide Sr (OH)₂, Magnesium hydroxide Mg (OH)₂, Aluminum hydroxide Al (OH)_Three, Europium hydroxide Eu (OH)₂In a molar ratio according to 0.02 ≦ x ≦ 0.2, 0.1 ≦ y ≦ 0.5, 9.50 ≦ a ≦ 9.98, 16.25 ≦ b ≦ 16.995 Weigh and use AlF as flux_ThreeAnd then calcined in air at 1400 ° C. for 2 hours and then calcined in a reducing atmosphere, for example, in a 5% hydrogen and 95% nitrogen atmosphere at a predetermined temperature (1000 ° C. to 1600 ° C. for 2 hours). A blue phosphor powder is produced by classifying the obtained powder with a classifier. Or, further, in order to make a part of Eu divalent trivalent, similarly O₂, O₂-N₂Or O_Three-N₂Bake in.
[0081]
Note that oxides, nitrates, and hydroxides are mainly used as phosphor materials, but organometallic compounds containing elements such as Ba, Sr, Mg, Al, and Eu, such as metal alkoxides and acetylacetone are used. Even if it uses, it can produce.
[0082]
(2) Green phosphor
(Zn_2-XSiO_Four: Mn_Xabout)
First, in the mixed liquid preparation step, zinc nitrate Zn (NO, which is a raw material)_Three), Silicon nitrate Si (NO_Three)₂, Manganese nitrate Mn (NO_Three)₂Was mixed at a molar ratio of 2-X: 1: X (0.01 ≦ X ≦ 0.10), and then this mixed solution was heated to 1500 ° C. while applying ultrasonic waves from a nozzle. To produce a green phosphor.
(Ba_1-XAl₁₂O₁₉: Mn_Xabout)
First, in the mixed liquid preparation process, the raw material, barium nitrate Ba (NO_Three)₂, Aluminum nitrate Al (NO_Three)₂, Manganese nitrate Mn (NO_Three)₂Are mixed so that the molar ratio is 1-X: 12: X (0.01 ≦ X ≦ 0.10), and this is dissolved in ion-exchanged water to prepare a mixed solution.
[0083]
Next, in the hydration step, a basic aqueous solution (for example, an aqueous ammonia solution) is dropped into this mixed solution to form a hydrate. Thereafter, in the hydrothermal synthesis step, the hydrate and ion-exchanged water are placed in a capsule made of corrosion-resistant or heat-resistant material such as platinum or gold, and the temperature is set at a predetermined temperature in a high-pressure vessel using an autoclave, for example. Hydrothermal synthesis is performed for a predetermined time (for example, 2 to 20 hours) under conditions of pressure (for example, a temperature of 100 to 300 ° C. and a pressure of 0.2 MPa to 10 MPa). Then, by drying, the desired Ba_1-XAl₁₂O₁₉: Mn_XIs obtained. By this hydrothermal synthesis step, the phosphor obtained has a particle size of about 0.1 μm to 2.0 μm and a spherical shape. Next, the powder is annealed in air at 800 ° C. to 1100 ° C. and then classified to obtain a green phosphor.
[0084]
(3) Red phosphor
(Y, Gd)_1-XBO_Three: Eu_Xabout)
Yttrium nitrate Y, which is a raw material in the mixed liquid preparation process₂(NO_Three)_ThreeAnd gadolinium nitrate Gd₂(NO_Three)_ThreeAnd boric acid H_ThreeBO_ThreeAnd europium nitrate Eu₂(NO_Three)_ThreeAnd mixed so that the molar ratio is 1-X: 2: X (0.05 ≦ X ≦ 0.20) (the ratio of Y to Gd is 65 to 35), After heat treatment at 1200 ° C. to 1350 ° C. for 2 hours, classification is performed to obtain a red phosphor.
(Y_2XO_Three: Eu_Xabout)
Yttrium nitrate Y, which is a raw material in the mixed liquid preparation process₂(NO_Three)₂And europium nitrate Eu (NO_Three)₂Are mixed in ion-exchanged water so that the molar ratio is 2-X: X (0.05 ≦ X ≦ 0.30) to prepare a mixed solution.
[0085]
Next, in the hydration step, a basic aqueous solution (for example, an aqueous ammonia solution) is added to this aqueous solution to form a hydrate.
[0086]
Thereafter, in the hydrothermal synthesis step, the hydrate and ion-exchanged water are placed in a container having corrosion resistance and heat resistance such as platinum and gold, and the temperature is set to 100 to 300 ° C. in a high pressure container using, for example, an autoclave. The hydrothermal synthesis is performed for 3 to 12 hours under conditions of a pressure of 0.2 MPa to 10 MPa. Thereafter, the obtained compound is dried to obtain the desired Y_2XO_Three: Eu_XIs obtained.
[0087]
Next, this phosphor is annealed in air at 1300 ° C. to 1400 ° C. for 2 hours and then classified to obtain a red phosphor. The phosphor obtained by this hydrothermal synthesis step has a particle size of about 0.1 μm to 2.0 μm and a spherical shape. The particle size and shape are suitable for forming a phosphor layer having excellent light emission characteristics.
[0088]
In the PDP 100 described above, the phosphor layers 110R and 110G are phosphors conventionally used, and the phosphor layer 110B has a configuration using the phosphor of the present invention. In particular, the conventional blue phosphor is greatly deteriorated due to damage received from each step as compared with the blue phosphor of the present invention, and therefore the white color temperature tends to decrease when the three colors emit light simultaneously. Therefore, in the PDP, a method of improving the color temperature of white display by reducing the luminance of cells of phosphors other than blue (red, green) in terms of circuit has been adopted. Is used, the luminance of the blue cell is increased and the deterioration during the panel manufacturing process is small, so that it is not necessary to intentionally lower the luminance of the cells of other colors. Therefore, since the luminance of all the color cells can be fully used, the luminance of the PDP can be increased while maintaining a high color temperature for white display.
[0089]
The blue phosphor according to the present invention can also be applied to fluorescent lamps that are excited and emitted by the same ultraviolet rays. When the phosphor according to the present invention is applied to a fluorescent lamp, it is possible to obtain a lamp that is superior in luminance and luminance degradation than a conventional fluorescent lamp.
[0090]
Hereinafter, in order to evaluate the performance of the PDP of the present invention, a sample based on the above embodiment was produced, and a performance evaluation experiment was performed on the sample. The experimental results are examined.
[0091]
Each PDP produced has a size of 42 inches (HD-TV specification with a rib pitch of 150 μm), the thickness of the dielectric glass layer is 20 μm, the thickness of the MgO protective layer is 0.5 μm, and between the display electrode and the display scan electrode The distance was made to be 0.08 mm. The discharge gas sealed in the discharge space is a gas in which 5% xenon gas is mixed mainly with neon, and is sealed at a predetermined discharge gas pressure.
[0092]
Each blue phosphor particle used in the PDP of samples 1 to 6 is Ba_1-xEu_xMgAl_aO_bOf the β-alumina crystal structure, the atomic ratios x, a, and b of the Ba, Eu, Al, and O ions constituting the phosphor, the ratio of Eu to divalent and trivalent, and respective synthesis conditions Is shown in Table 1.
[0093]
Each blue phosphor particle used in the PDPs of Samples 7 to 11 is Ba_1-xyEu_xSr_yMgAl_aO_bTable 1 shows the values of the atomic ratios x, y, a, and b of the Ba, Sr, Eu, Al, and O ions constituting the phosphor having the β-alumina crystal structure and the amounts of Eu trivalence and the respective synthesis conditions. Show.
[0094]
[Table 1]

[0095]
Samples 1 to 6 are red phosphors (Y, Gd)_1-xBO_Three: Eu_xZn in green phosphor_2-xSiO_Four: Mn_xBa on blue phosphor_(1-x)Eu_xMgAl_aO_bA combination method using phosphors, a substitution ratio of Eu and Mn serving as emission centers, that is, a substitution ratio of Eu with respect to Y and Ba elements, and a substitution ratio of Mn with respect to Zn elements, and divalent In Table 1, the amount of trivalent Eu ions to be substituted with Eu ions is changed as shown in Table 1. Samples 7 to 11 are red phosphors (Y, Gd)_1-xBO_Three: Eu_xZn in green phosphor_2-xSiO_Four: Mn_xBa on blue phosphor_(1-xy)Eu_xSr_yMgAl_aO_bIn the same manner as described above, the phosphor synthesis method conditions, the substitution ratio of the luminescent center, the substitution amount of Ba or Sr constituting the blue phosphor into Eu (x), the amount of Al, a, The amount b of O and the ratio of the amount of divalent Eu ions to trivalent Eu ions are changed as shown in Table 1.
[0096]
The phosphor ink used for forming the phosphor layer was prepared by mixing phosphor, resin, solvent and dispersant using each phosphor particle shown in Table 1.
[0097]
As for the result measured about the viscosity (25 degreeC) of the phosphor ink at that time, the viscosity is maintained in the range of 1500-30000CP in all cases. When the formed phosphor layers were observed, the phosphor ink was uniformly applied to the wall surfaces of the partition walls, and could be applied for 200 hours without clogging.
[0098]
Moreover, about the fluorescent substance particle used for the fluorescent substance layer in each color, the thing with the average particle diameter of 0.1 micrometer-3.0 micrometers and the maximum particle diameter of 8 micrometers or less is used for each sample.
[0099]
Sample 12 is Ba_0.6Eu_0.1(Sr_0.3) MgAl_TenO₁₇Then, all the Eu is divalent blue phosphor particles.
[0100]
Sample 13 is Ba_0.9Eu_0.1MgAl₁₄O_{twenty three}In this case, blue phosphor particles having a trivalent ratio of Eu of 30% were used.
[0101]
Sample 14 is Ba_0.9Eu_0.1MgA_19.4O_16.1All of the phosphors used were blue phosphor particles having a bivalent Eu.
[0102]
Sample 15 is Ba_0.9Eu_0.1MgA_19.4O_16.165In this case, blue phosphor particles having a trivalent ratio of Eu of 30% were used.
[0103]
In addition, the bivalent and trivalent measurement of Eu ion of Table 1 was measured by XANES (X-ray Absorption Near Edge Structure) spectrum method.
[0104]
(Experiment 1)
About the produced samples 1-11 and comparative samples 12-15, after the fluorescent substance baking process (520 degreeC, 20 minutes) in a back panel manufacturing process, 147 nm ultraviolet light (Ushio Excimer lamp HD0012) is modeled 200 times. The rate of change in the luminance of the blue phosphor upon time irradiation was measured.
[0105]
(Experiment 2)
The brightness when the panel is turned on for each color and the brightness deterioration rate of the blue phosphor are measured by continuously applying a discharge sustaining pulse with a voltage of 200 V and a frequency of 100 kHz to the PDP for 500 hours, and measuring the panel brightness before and after that. From that, the rate of change in luminance deterioration was determined by ((luminance after application-luminance before application) / luminance before application) × 100.
[0106]
(Experiment 3)
The luminance when only the blue color of the panel was turned on was measured by applying a voltage of 180 V and a frequency of 50 kHz to the display electrode portion of the PDP.
[0107]
Further, an address miss at the time of PDP address discharge is determined by checking whether there is flicker by looking at the image, and if there is even one place.
[0108]
Table 2 shows the results of the luminance and the luminance deterioration change rate of the blue phosphor layer portions of Experiments 1 to 3.
[0109]
[Table 2]

[0110]
As shown in Table 2, in Comparative Samples 12 to 15, Ba_(1-x)Eu_xMgAl_aO_bOr Ba_(1-xy)Eu_xSr_yMgAl_aO_bIn the blue phosphor, the sample whose a value is outside the range of 9.50 ≦ a ≦ 9.98 has a large deterioration rate of −4.5% to −41.5% by 147 nm ultraviolet irradiation, and is maintained. The luminance deterioration rate in discharge (applied with a sustain discharge pulse of 200 V, 100 kHz for 500 hours) is also large.
[0111]
On the other hand, in all of the sample samples 1 to 11, the change rate of the blue color due to the irradiation with ultraviolet rays of 147 nm is a value of 2.8% or less, and the deterioration of the panel during the sustain discharge pulse driving is reduced. There are no mistakes.
[0112]
This is because oxygen defects (especially oxygen defects in the vicinity of Ba-O) in the blue phosphor are greatly reduced by setting the amount of Al constituting the blue phosphor to 9.50 ≦ a ≦ 9.98. It is. It can also be seen that, in addition to setting the value of a in Al to 9.50 ≦ a ≦ 9.98, the deterioration due to ultraviolet rays can be further suppressed by making a part of Eu bivalent trivalent.
[0113]
(Experiment 4)
As a model experiment, Samples 1 to 11 in which the range of the amount of Al of the blue phosphor is 9.50 at% to 9.98 at% are compared with the samples in the above range (Comparative Examples 12 to 15). After standing at 60 ° C. and 90% relative humidity for 10 minutes, and then drying at 100 ° C., TDS analysis (temperature-programmed desorption gas mass spectrometry) of these phosphors was carried out. As a result, physical adsorption of water (100 ° C. Near) and chemisorption (300 ° C. to 500 ° C.) peak was found to be 1/10 or less.
[0114]
【The invention's effect】
As described above, according to the present invention, by eliminating oxygen defects near the Ba-containing layer (Ba-O layer), water adsorption on the surface of the blue phosphor is suppressed, and luminance degradation and color of the phosphor are suppressed. It is possible to realize a PDP capable of performing good image display by changing the degree of discharge and improving discharge characteristics.
[Brief description of the drawings]
FIG. 1 is a plan view of a plasma display panel according to an embodiment of the present invention excluding a front glass substrate.
FIG. 2 is a cross-sectional perspective view showing a part of the structure of an image display region of a plasma display panel according to an embodiment of the present invention.
FIG. 3 is a block diagram of a plasma display apparatus using a plasma display panel according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a structure of an image display region of a plasma display panel according to an embodiment of the present invention.
FIG. 5 is a schematic configuration diagram of an ink coating apparatus used when forming a phosphor layer of a plasma display panel according to an embodiment of the present invention.
FIG. 6 is a diagram showing a schematic atomic structure of a phosphor according to an embodiment of the present invention.
[Explanation of symbols]
100 PDP
101 Front glass substrate
102 Back glass substrate
103 Display electrode
104 Display scan electrode
105 Dielectric glass layer
106 MgO protective layer
107 Address electrode
108 Dielectric glass layer
109 Bulkhead
110R phosphor layer (red)
110G phosphor layer (green)
110B phosphor layer (blue)
122 Discharge space
123 discharge cells

Claims (1)

A plasma display panel in which a plurality of discharge cells of one color or a plurality of colors are arranged and a phosphor layer of a color corresponding to each discharge cell is disposed,
The phosphor layer has a blue phosphor layer, and the blue phosphor layer is
Is composed of _{Ba (1-x) Eu x} MgAl a O b or _{Ba (1-x-y)} Eu x Sr y MgAl a O b compound represented by,, 0.02 ≦ x ≦ 0.2,0 .1 ≦ y ≦ 0.5, 9.50 ≦ a ≦ 9.98, 16.25 ≦ b ≦ 16.995,
In addition, by firing at 700 ° C. to 1000 ° C. in an oxidizing atmosphere, among the Eu ions, divalent ones are 30% to 90%, trivalent ones are 10% to 70%, and the average particle size is It was formed using a blue phosphor that is 0.1 μm to 3.0 μm
A plasma display panel characterized by that .

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