JP2004207047A - Phosphor layer and plasma display panel using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower discharge start voltage of a phosphor layer. <P>SOLUTION: The phosphor layer arranged in a discharge space, comprises an inorganic oxide which is positively charged when voltage is applied. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００２３】
表１から、無機酸化物を蛍光体層に含有させることで放電開始電圧を下げることが可能であることがわかった。また、無機酸化物を含有しない赤色蛍光体層、ＭｇＯを１重量％含む緑色蛍光体層、Ｙ₂Ｏ₃を１重量％又はＭｇＯを０．３重量％含む青色蛍光体層を組み合わせることで、放電開始電圧のほぼ均一なフルカラーＰＤＰを得ることが可能であることがわかった。
【００２４】
実施例２
蛍光体層としてＣａＭｇＳｉ₂Ｏ₆：Ｅｕ²⁺（青色蛍光体）に、無機酸化物未含有、ＭｇＯを０．１重量％、０．３重量％と１重量％含有する４種の構成の蛍光体層を使用すること以外は、実施例１と同様にしてＰＤＰを作製した。得られたＰＤＰの放電開始電圧及び輝度を表２及び図３に示す。
【００２５】
【表２】

【００２６】
表２及び図３から、無機酸化物を含有させることで放電開始電圧を大きく下げることができるのに対して輝度の低下が抑制されていることがわかった。
【００２７】
【発明の効果】
本発明によれば、電圧を印加した際に正に帯電する無機酸化物を蛍光体層に含ませることで、蛍光体自体の組成を変えずに、蛍光体層の放電開始電圧を下げることができる。
また、蛍光体層が複数存在する場合、最も正に帯電する蛍光体よりも正に帯電する無機酸化物を、最も正に帯電する蛍光体を含む蛍光体層以外の蛍光体層に含ませることで、全蛍光体層の放電開始電圧を低減することができる。
【図面の簡単な説明】
【図１】本発明の蛍光体層の概略図である。
【図２】ＰＤＰの概略斜視図である。
【図３】実施例２のＰＤＰの放電開始電圧及び輝度とＭｇＯの含有量との関係を示すグラフである。
【符号の説明】
１、２８ 蛍光体層
２ 無機酸化物
３ 蛍光体
１１、２１ 基板
１７、２７ 誘電体層
１８ 保護層
２９ 隔壁
４１ 透明電極
４２ バス電極
１００ ＰＤＰ
Ａ アドレス電極
Ｒ 赤色の発光を生じる領域
Ｇ 緑色の発光を生じる領域
Ｂ 青色の発光を生じる領域[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a phosphor layer provided in a discharge space and a plasma display panel using the same. More specifically, the present invention relates to a phosphor layer that converts irradiated light into light having lower energy (longer wavelength) than the light, and a plasma display panel using the same.
[0002]
[Prior art]
The phosphor layer is used in a plasma display panel (PDP), a fluorescent lamp, and the like to convert irradiated light (for example, ultraviolet light) into light (for example, visible light) having lower energy (longer wavelength) than that light. It is used.
For example, in a typical PDP for color display, display cells (also referred to as discharge cells) of three colors of red, blue and green are arranged in a discharge space between a front plate and a back plate in a matrix. More specifically, on the front plate, a plurality of pairs of display electrodes of X electrodes and Y electrodes for plasma discharge are arranged in parallel. On the other hand, the back plate is provided with an address electrode for generating a selective discharge in each cell, and a partition for partitioning the discharge space on a cell-by-cell basis. Three types of phosphor layers, a phosphor layer and a blue phosphor layer, are individually provided (for example, JP-A-2001-172006-Patent Document 1).
[0003]
[Patent Document 1]
JP 2001-172006 A
[Problems to be solved by the invention]
Discharge cells of the PDP have different firing voltages depending on the types of phosphors provided in the cells. If the discharge start voltage is high, power consumption during light emission increases, and it has been desired to lower the discharge start voltage.
Further, it is desired that the discharge start voltage of each discharge cell having the red phosphor layer, the green phosphor layer, and the blue phosphor layer is uniform.
That is, (Y, Gd) BO ₃ : Eu, Zn ₂ SiO ₄ : Mn and (Ba, Eu) MgAl are representative phosphors contained in the red phosphor layer, the green phosphor layer and the blue phosphor layer, respectively. ₁₀ O ₁₇ : Eu is known. The discharge starting voltages of the discharge cells employing these phosphors are 249 V, 290 V, and 254 V, respectively, and the discharge starting voltage of the green phosphor is particularly high. In a PDP, a discharge is generated between a display electrode and an address electrode in order to equalize (also referred to as initialization) a wall charge state of a discharge cell group forming a pixel at the beginning of a driving sequence at the time of display. The amplitude of the voltage pulse required for the initialization is set according to the highest discharge starting voltage of the green phosphor. Therefore, the red and blue phosphors having a lower firing voltage than the green phosphor emit light more intensely than the green phosphor. The light emission in the initialization is unnecessary light emission for display, and there is a problem that when the light emission of the red and blue phosphors is increased, the contrast is reduced.
[0005]
[Means for Solving the Problems]
Thus, according to the present invention, there is provided a phosphor layer provided in a discharge space, wherein the phosphor layer contains an inorganic oxide that is positively charged when a voltage is applied. .
Further, according to the present invention, there is provided a plasma display panel including the above-mentioned phosphor layer.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
For example, the charge amount of the phosphor for PDP is about 50 μC / g ((Y, Gd) BO ₃ : Eu) for the red phosphor, about −40 μC / g (Zn ₂ SiO ₄ : Mn) for the green phosphor, and Blue phosphor: about 60 μC / g (BaMgAl ₁₀ O ₁₇ : Eu), and the charge amount of the green phosphor is lower than other phosphors. The magnitude of the charge amount has a correlation with the magnitude of the discharge start voltage (both the charge amount and the discharge start voltage are smaller in the order of blue, red, and green).
[0007]
From the above viewpoints, the inventors of the present invention have found that the discharge starting voltage can be controlled by controlling the charge amount of the phosphor. However, if the composition of the phosphor itself is changed in order to control the amount of charge of the phosphor, the luminance and life characteristics of the phosphor may be degraded. Therefore, in order to change the amount of charge of the phosphor layer without changing the composition of the phosphor itself, an inorganic oxide that is positively charged when a voltage is applied is included in the phosphor layer, so that the phosphor layer has The present inventors have found that the discharge starting voltage can be controlled, and have reached the present invention.
[0008]
When there is an inorganic oxide capable of imparting an electron-emitting property to the phosphor that is positively charged when a voltage is applied to the phosphor in the phosphor layer, the oxide facilitates the emission of electrons into the discharge space, and this causes a trigger. As a result, discharge can be started at a lower voltage than when no oxide is present.
In the present invention, the charge amount was measured by a blow-off method and quoted from Toshihiko Oguchi, Masaaki Tamaya, Journal of the Electrostatics Society of Japan, 7, 5 (1983) 292-299.
[0009]
The phosphor layer of the present invention comprises a phosphor and an inorganic oxide that is positively charged when a voltage is applied. The phosphor that can be used in the present invention is not particularly limited, and any known phosphor in the art can be used. For example, as a red phosphor, Y ₂ O ₃ : Eu, (Y, Gd) BO ₃ : Eu, YVO ₄ : Eu, Y ₂ O ₃ S: Eu, Zn ₃ (PO ₄ ) ₂ : Mn, ( ZnCd) S: Ag + InO and the like. Green phosphors include Zn ₂ SiO ₄ : Mn, BaAl ₁₂ O ₁₉ : Mn, (Ba, Sr, Mg) O.aAl ₂ O ₃ : Mn, Zn ₂ GeO ₂ : Mn, LaPO ₄ : Tb, ZnS : (Cu, Al), ZnS : (Au, Cu, Al), (ZnCd) S: (Cu, Al), Zn 2 SiO 4: (Mn, As), Y 3 Al 5 O 12: Ce, Gd 2 O ₂ S: Tb, Y ₃ Al ₅ O ₁₂ : Tb, ZnO: Zn and the like can be mentioned. Blue phosphors include BaMgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₄ O ₂₃ : Eu, BaMgAl ₁₆ O ₂₇ : Eu, Sr ₅ (PO ₄ ) ₃ Cl: Eu, Y ₂ SiO ₃ : Ce, CaMgSi ₂ O ₆ : Eu and the like.
[0010]
Of the above phosphors, (Y, Gd) BO ₃ : Eu) having a charge of about 50 μC / g as a red phosphor, Zn ₂ SiO ₄ : Mn and a blue phosphor having a charge of about −40 μC / g as a green phosphor. It is preferable to use about 60 μC / g of BaMgAl ₁₀ O ₁₇ : Eu or about 10 μC / g of CaMgSi ₂ O ₆ : Eu.
On the other hand, the inorganic oxide that is positively charged when a voltage is applied is not particularly limited, but is preferably a substance that is more positively charged than the phosphor. For example, MgO (about 260 μC / g), ZnO (about 160 μC / g), PbO (about 150 μC / g), Eu ₂ O ₃ (about 100 μC / g), HgO (about 90 μC / g), Al ₂ O ₃ ( About 80 μC / g), Nd ₂ O ₃ (about 80 μC / g), Tm ₂ O ₃ (about 80 μC / g), Dy ₂ O ₃ (about 80 μC / g), Tl ₂ O ₃ (about 80 μC / g), Y ₂ O ₃ (about 70 μC / g), In ₂ O ₃ (about 70 μC / g), La ₂ O ₃ (about 70 μC / g), CdO (about 60 μC / g), Bi ₂ O ₃ (about 60 μC / g) ), CoO (about 40 μC / g), HfO ₂ (about 40 μC / g), CuO (about 40 μC / g), NiO (about 30 μC / g), Sc ₂ O ₃ (about 30 μC / g), Ga ₂ O ₃ (About 30 μC / g), CeO ₂ (about 20 μC / g), Cr ₂ O ₃ (about 10 μC / g), MnO ₂ (about 1 μC / g) 0 [mu] C / g) or the like according to the charge amount of the target phosphor (parentheses indicate the charge amount). Among them, it is preferable to use MgO and Y ₂ O ₃ .
[0011]
The amount of the inorganic oxide added to the phosphor layer is appropriately adjusted so that the charge amount of the phosphor layer becomes a predetermined value. The specific addition amount is preferably, for example, 0.001% by weight or more based on the entire phosphor layer. When the amount of the inorganic oxide added is increased, the amount of the phosphor in the phosphor layer is relatively reduced, and as a result, characteristics such as luminance may be reduced. Therefore, the addition amount is more preferably in the range of 0.001 to 10% by weight. A particularly preferred range is from 0.01 to 5% by weight.
[0012]
In the present invention, as shown in FIG. 1, the phosphor layer 1 contains the inorganic oxide 2 so as to stick to the phosphor 3. Here, it is conceivable to form the inorganic oxide as a layer on the phosphor layer, but in this case, the inorganic oxide layer may hinder light emission from the phosphor layer, and the luminance of the phosphor layer may be reduced. It is not preferable because there is.
Further, according to the present invention, there is provided a PDP or a gas discharge lamp comprising the above-mentioned phosphor layer.
Hereinafter, an example in which the phosphor layer of the present invention is applied to the PDP of FIG. 2 will be described.
[0013]
The PDP of FIG. 2 is the above-described representative three-electrode AC type surface discharge PDP. The present invention is not limited to this PDP, and can be applied to any configuration as long as the PDP includes a phosphor. For example, not only the AC type but also a DC type may be used for any of a reflection type and a transmission type PDP.
The PDP 100 of FIG. 2 includes a front substrate and a rear substrate.
First, the front substrate includes a plurality of display electrodes formed on the substrate 11, a dielectric layer 17 formed to cover the display electrodes, a protective layer 18 formed on the dielectric layer 17 and exposed to the discharge space. Consists of
[0014]
The substrate 11 is not particularly limited, and examples thereof include a glass substrate, a quartz glass substrate, and a silicon substrate.
The display electrode includes a transparent electrode 41 such as ITO. Further, a bus electrode (for example, a three-layer structure of Cr / Cu / Cr) 42 may be formed on the transparent electrode 41 in order to reduce the resistance of the display electrode.
The dielectric layer 17 is formed from a material commonly used for a PDP. Specifically, it can be formed by applying a paste composed of a low-melting glass and a binder on a substrate and firing the paste.
The protective layer 18 is provided to protect the dielectric layer 17 from damage caused by ion collisions caused by discharge during display. The protective layer 18 is made of, for example, MgO, CaO, SrO, BaO, or the like.
[0015]
Next, the rear substrate includes a plurality of address electrodes A formed on the substrate 21 in a direction crossing the display electrodes, a dielectric layer 27 covering the address electrodes A, and a dielectric layer 27 between the adjacent address electrodes A. It comprises a plurality of stripe-shaped barrier ribs 29 formed thereon, and a phosphor layer 28 formed between the barrier ribs 29 including the wall surface. In FIG. 2, R, G, and B mean unit light emitting regions (discharge cells) that emit red, green, and blue light.
As the substrate 21 and the dielectric layer 27, the same type as the substrate 11 and the dielectric layer 17 constituting the front substrate can be used.
[0016]
The address electrode A has, for example, a metal layer of Al, Cr, Cu, or the like, or a three-layer structure of Cr / Cu / Cr.
The partition wall 29 can be formed by applying a paste composed of a low-melting glass and a binder on the dielectric layer 27, drying the paste, and cutting it by a sandblast method. When a photosensitive resin is used for the binder, the binder can be formed by exposing and developing using a mask having a predetermined shape, and then firing.
[0017]
In FIG. 2, the phosphor layer 28 is formed between the partition walls 29, but the phosphor layer 1 shown in FIG. 1 of the present invention can be used for this phosphor layer 28. In FIG. 2, three types of phosphor layers, a red phosphor layer, a green phosphor layer, and a blue phosphor layer, are provided, but one phosphor layer, two phosphor layers, and four or more phosphor layers. A body layer may be provided. When a plurality of types of phosphor layers are provided, the above-mentioned inorganic oxide can be contained in all the phosphor layers or an arbitrary phosphor layer, but the above-mentioned inorganic oxide is contained in the phosphor layer having the smallest charge amount. It is preferable to include them. In particular, by including an inorganic oxide that is more positively charged than the most positively charged phosphor in a phosphor layer other than the phosphor layer containing the most positively charged phosphor, discharge of all the phosphor layers is started. Voltage can be reduced.
[0018]
Further, by adjusting the type and amount of the inorganic oxide, the difference between the highest discharge start voltage and the lowest discharge start voltage can be set to 20 V or less. For example, when (Y, Gd) BO ₃ : Eu is used for the red phosphor, Zn ₂ SiO ₄ : Mn is used for the green phosphor, and BaMgAl ₁₀ O ₁₇ : Eu is used for the blue phosphor, 1 wt. %, And if the blue phosphor contains 1% by weight of Y ₂ O ₃ , the discharge starting voltage can be made substantially constant at about 248V.
The method for forming the phosphor layer 28 is not particularly limited, and may be a known method. For example, a paste in which a phosphor and an inorganic oxide are dispersed in a solution in which a binder is dissolved in a solvent is applied between the partition walls 29, and the paste is fired under an inert atmosphere to form the phosphor layer 28. Can be.
[0019]
Next, the front substrate and the rear substrate are opposed to each other so that the display electrodes (41, 42) and the address electrodes A are orthogonal to each other with both electrodes inside, and the space surrounded by the partition wall 29 is filled with a discharge gas. Thus, the PDP 100 can be formed.
In the PDP, the phosphor layer is formed on the partition and the dielectric layer among the partition, the dielectric layer, and the protective film that define the discharge space. May be formed.
[0020]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.
Example 1
PDPs provided with the following 15 types of phosphor layers were produced.
Red phosphor (Y, Gd) BO ₃ : Eu ³⁺ containing no inorganic oxide, 0.3% and 1% by weight of MgO, 0.3% and 1% by weight of Y ₂ O ₃ containing the allowed phosphor layers, green phosphor layers Zn ₂ SiO _4: the Mn ^2+, inorganic oxides not containing 0.3 wt% of MgO and 1% by weight, and a Y ₂ O ₃ 0.3 wt% Phosphor layer / blue phosphor layer BaMgAl ₁₀ O ₁₇ : Eu ²⁺ containing 1% by weight, containing no inorganic oxide, 0.3% and 1% by weight of MgO and 0.3% by weight of Y ₂ O ₃ . Phosphor layer containing 3% by weight and 1% by weight A three-electrode surface discharge PDP having the following configuration was prepared except for the configuration of the above-mentioned phosphor layer, and the discharge starting voltage was measured. Table 1 shows the results.
[0021]
Structure of PDP:
Display electrode Transparent electrode width: 280 μm, bus electrode width 100 μm
Discharge gap between display electrodes 100μm
Thickness of dielectric layer 30μm
Partition wall height 100 μm
Arrangement pitch of partition wall 360μm
Ne-Xe (5%) discharge gas pressure 500 Torr
[0022]
[Table 1]

[0023]
From Table 1, it was found that the discharge starting voltage can be reduced by including the inorganic oxide in the phosphor layer. By combining a red phosphor layer containing no inorganic oxide, a green phosphor layer containing 1% by weight of MgO, and a blue phosphor layer containing 1% by weight of Y ₂ O ₃ or 0.3% by weight of MgO, It has been found that it is possible to obtain a full-color PDP having a substantially uniform firing voltage.
[0024]
Example 2
Four types of fluorescent materials containing CaMgSi ₂ O ₆ : Eu ²⁺ (blue phosphor) as a phosphor layer, containing no inorganic oxide, and containing 0.1 wt%, 0.3 wt% and 1 wt% of MgO. A PDP was produced in the same manner as in Example 1 except that a body layer was used. Table 2 and FIG. 3 show the discharge start voltage and luminance of the obtained PDP.
[0025]
[Table 2]

[0026]
From Table 2 and FIG. 3, it was found that the discharge start voltage can be greatly reduced by including the inorganic oxide, but the decrease in luminance is suppressed.
[0027]
【The invention's effect】
According to the present invention, by including in the phosphor layer an inorganic oxide that is positively charged when a voltage is applied, the discharge start voltage of the phosphor layer can be reduced without changing the composition of the phosphor itself. it can.
Further, when there are a plurality of phosphor layers, the inorganic oxide that is more positively charged than the phosphor that is most positively charged should be included in the phosphor layers other than the phosphor layer containing the most positively charged phosphor. Thus, the firing voltage of all the phosphor layers can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic view of a phosphor layer of the present invention.
FIG. 2 is a schematic perspective view of a PDP.
FIG. 3 is a graph showing the relationship between the discharge starting voltage and the luminance of the PDP of Example 2 and the content of MgO.
[Explanation of symbols]
1, 28 phosphor layer 2 inorganic oxide 3 phosphor 11, 21 substrate 17, 27 dielectric layer 18 protective layer 29 partition 41 transparent electrode 42 bus electrode 100 PDP
A address electrode R area for emitting red light G area for emitting green light B area for emitting blue light

Claims (7)

A phosphor layer provided in a discharge space, wherein the phosphor layer contains an inorganic oxide that is positively charged when a voltage is applied. The phosphor layer according to claim 1, wherein the inorganic oxide is added in an amount of 0.001 to 10% by weight based on the entire phosphor layer. The phosphor layer according to claim 2, wherein the inorganic oxide is added in an amount of 0.01 to 5% by weight based on the entire phosphor layer. The inorganic oxide, MgO, ZnO, PbO, Eu 2 O 3, HgO, Al 2 O 3, Nd 2 O 3, Tm 2 O 3, Dy 2 O 3, Tl 2 O 3, Y 2 O 3, In ₂ O ₃ , La ₂ O ₃ , CdO, Bi ₂ O ₃ , CoO, HfO ₂ , CuO, NiO, Sc ₂ O ₃ , Ga ₂ O ₃ , CeO ₂ , Cr ₂ O ₃ , MnO ₂ and MgAl ₂ O ₄ The phosphor layer according to claim 1, wherein the phosphor layer is selected from the group consisting of: A plasma display panel comprising the phosphor layer according to claim 1 in a discharge cell. It has three phosphor layers, a red phosphor layer, a green phosphor layer, and a blue phosphor layer, and is more positively charged than the most positively charged phosphor among the three phosphor layers. The plasma display panel according to claim 5, wherein the charged inorganic oxide is contained at least in a phosphor layer other than the phosphor layer containing the most positively charged phosphor. 7. The plasma display panel according to claim 6, wherein a difference between the highest discharge start voltage and the lowest discharge start voltage among three types of discharge cells provided with three types of phosphor layers individually is 20 V or less.

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