JP2005330312A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display panel using a silicate blue phosphor slightly deteriorating emission luminance by irradiation of vacuum ultraviolet light with small temperature dependence of emission chromaticity. <P>SOLUTION: The plasma display panel is provided with a phosphor layer composed of a blue phosphor. In the plasma display panel, the blue phosphor contains metal ions having a larger ionic radius than that of an activator in a silicate phosphor containing Eu as the activator. The surface grade can be enhanced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plasma display (hereinafter referred to as PDP) using a phosphor that emits blue light with high luminous efficiency under excitation of vacuum ultraviolet rays (hereinafter referred to as VUV).

Several blue phosphors excited by VUV have already been proposed. Among them, BaMgAl ₁₀ O ₁₇ : Eu (in the composition formula: (colon) and below indicate elements added as activators) has been put into practical use, such as PDP and rare gas lamps. It is used as a blue phosphor.

  PDP generates plasma by discharge in a rare gas such as Ne, and excites phosphors by emitting VUV emitted from the plasma. However, there is a problem that the phosphor is deteriorated by the irradiation of VUV and the luminance is lowered. For this reason, there has been a demand for a phosphor with less luminance deterioration due to VUV irradiation.

Recently, CaMgSi ₂ O ₆ : Eu, which is one of silicate phosphors, has been studied as a blue phosphor with little luminance deterioration caused by VUV irradiation, instead of BaMgAl ₁₀ O ₁₇ : Eu (see Non-Patent Document 1). ).
Video Information Media Society Technical Report 2001 vol. 25 No. 71 p25-30

However, as a result of intensive investigations by the present inventors, the PDP using CaMgSi ₂ O ₆ : Eu has blue display CIE chromaticity (x, y) (hereinafter referred to as chromaticity) as the operating temperature increases. Found that there is an increasing problem. This phenomenon is not preferable because the temperature of the panel increases with the operation time during the actual operation of the PDP, and the hue gradually changes.

  An object of the present invention is to provide a PDP using a silicate blue phosphor having a small temperature dependency of emission chromaticity.

  The present invention solves the above-described problem, and in the plasma display panel including a phosphor layer made of a blue phosphor, the blue phosphor is added to the silicate phosphor containing Eu as an activator. It contains a base metal ion having an ionic radius larger than that of the activator.

Further, the present invention has the general formula _{lCaO · mM1O · nM2O · 2SiO 2} (M1 represents at least one selected from Sr and Ba, M2 is at least one selected from Mg and Zn, l and m are 0 .1 to 3.4 and n is 0.5 to 2.5, provided that 0.5 ≦ l + m ≦ 3.5.) Eu, Mn as activators It contained at least 1 sort (s) chosen from.

  ADVANTAGE OF THE INVENTION According to this invention, PDP using the silicate blue fluorescent substance with little degradation of the luminescent brightness by VUV irradiation and little temperature dependence of luminescent chromaticity can be provided.

First, the phosphor of the present invention have the general formula _{lCaO · mM1O · nM2O · 2SiO 2} (M1 represents at least one selected from Sr and Ba, M2 is at least one selected from Mg and Zn, l and m is 0.1 or more and 3.4 or less, and n is 0.5 or more and 2.5 or less, provided that 0.5 ≦ l + m ≦ 3.5. The present invention relates to a silicate phosphor containing at least one selected from Eu and Mn.

  Here, according to the experiments by the present inventors, when l + m and n are out of the above range, the light emission luminance is low, the luminance deterioration of the phosphor due to VUV irradiation is large, and l and m are out of the above range. As a result, the temperature dependence of the emission chromaticity increases.

Furthermore, the phosphor composition formula _{Ca 1-ab M1 a MgSi 2} O 6: Eu b (. A is 0.1 to 0.9, d is greater than 0 less than 0.1) in A phosphor having the composition represented is preferred. Outside the range of a and c in the composition formula, it is not preferable because problems such as relatively high temperature dependence of emission luminance and low emission luminance occur.

Next, although the manufacturing method of the fluorescent substance by this invention is demonstrated, it is not limited to this. The phosphor of the present invention can be obtained, for example, by mixing a metal element compound represented by the above composition formula and firing it. As raw materials for calcium, strontium, barium, magnesium, and zinc contained in the phosphor of the present invention, compounds that can be decomposed into oxides at high temperatures, such as hydroxides, carbonates, halides, nitrates, and oxalates, or An oxide can be used. For example, CaCO ₃ , SrCO ₃ , MgCO ₃ , SiO ₂ , Eu ₂ O ₃ has a molar ratio of Ca: Sr: Mg: Si: Eu of 0.63: 0.27: 1: 2: 0.1. Thus, it can manufacture by baking after mix | blending and mixing. For mixing these raw materials, for example, a ball mill, a V-type mixer, a stirrer, or the like can be used.

After mixing, for example, the phosphor of the present invention is obtained by firing for 1 to 50 hours in a temperature range of 1000 to 1300 ° C. The firing atmosphere is not particularly limited, but for example, firing in a reducing atmosphere such as nitrogen or argon containing 0.1 to 10% by volume of hydrogen is desirable. Further, in order to promote the firing reaction, an appropriate amount of flux such as B ₂ O ₃ or CaCl ₂ may be added. Furthermore, the phosphor after firing can be crushed using a ball mill or the like.

  The phosphor obtained by the above method can be used in a PDP as a phosphor that is excited by VUV and exhibits high emission luminance, little luminance deterioration due to VUV irradiation, and low temperature dependency of emission chromaticity.

  Next, the configuration of the PDP using the blue phosphor manufactured by the above-described method will be described with reference to FIG. 1 taking an AC type PDP as an example.

  As shown in FIG. 1, the PDP is configured by disposing a front substrate 1 and a rear substrate 2 so as to face each other with a discharge space 3 interposed therebetween, and sealing a peripheral portion with a sealing member. On the front substrate 1 made of a transparent material such as glass, a plurality of display electrode pairs 4 made of stripe-shaped scan electrodes and sustain electrodes arranged in parallel to each other are formed so as to cover the display electrode pairs 4. A dielectric layer 5 made of a glass material is formed, and a protective layer 6 made of MgO is further formed on the dielectric layer 5.

  Further, a plurality of striped Ag data electrodes 7 are formed on the rear substrate 2 so as to be orthogonal to the display electrode pairs 4 and to form discharge cells at the intersections between the data electrodes 7. A partition wall 8 is formed on the back substrate 2. Although not shown, an insulator layer made of a glass material is formed on the data electrode 7.

Further, a phosphor layer 9 is formed on the insulator layer so as to cover the data electrode 7 between the barrier ribs 8 of the rear substrate 2, and the red, green and blue phosphor layers 9 are sequentially arranged. . The phosphor layers 9 of each color are composed of a red phosphor (Y, Gd) BO ₃ : Eu, a green phosphor Zn ₂ SiO ₄ : Mn, and a blue phosphor Ca _0.63 Sr _0.27 MgSi ₂ O ₆ prepared by the above-described manufacturing method: It is formed using Eu. Further, the discharge space 3 is filled with a mixed gas of at least one kind of rare gas and xenon among helium, neon, and argon.

  The display image is viewed from the front substrate 1 side, which is the display surface side of this PDP, and the phosphor layer 9 is generated by VUV generated by discharge between the scan electrodes and the sustain electrodes constituting the display electrode pair 4. Emits visible light and performs color display.

  In the PDP using the phosphor of the present invention, the temperature dependence of the emission chromaticity of the blue phosphor used in the phosphor layer 9 is low, and the change in the emission chromaticity of the blue phosphor due to the heat generated by the actual operation of the PDP. Is suppressed, and a high-quality display can be maintained. Next, the effect of this invention is demonstrated using a specific Example.

(Example)
Calcium carbonate CaCO ₃ , strontium carbonate SrCO ₃ , magnesium carbonate MgCO ₃ , silicon oxide SiO ₂ , europium oxide Eu ₂ O ₃ and Ca: Sr: Mg: Si: Eu 0.63: 0.27: 1: 2: 0 1 and weighed for 30 minutes using a ball mill, mortar or the like. The obtained mixture was baked at 1100 ° C. in a nitrogen atmosphere containing 2% by volume of hydrogen for 2 hours. Furthermore, the obtained compound was pulverized with a ball mill to obtain a target phosphor. And the PDP which formed the fluorescent substance layer using the blue fluorescent substance obtained in this way was created.

  The temperature dependency of the chromaticity in blue display of the PDP according to the embodiment of the present invention is that the phosphor layer temperature inside the PDP cannot be measured. Therefore, by measuring the chromaticity change with respect to the temperature change from the room temperature of the front substrate. Measurements were made. The PDP was displayed only for a certain range used for measurement, and heated by the heat generated by the operation.

As a result, the chromaticity coordinates (x, y) at room temperature indicate (0.163, 0.053), and the chromaticity coordinate changes (Δx, Δy) at 60 ° C. are (0.003, 0.002). )Met. When the blue display with the front substrate temperature of 60 ° C. and the blue display with room temperature were compared with the naked eye, the difference in color could hardly be confirmed.

(Comparative example)
Calcium carbonate CaCO ₃ , magnesium carbonate MgCO ₃ , silicon oxide SiO ₂ , europium oxide Eu ₂ O ₃ were weighed so that Ca: Mg: Si: Eu was 0.9: 1: 2: 0.1, a ball mill, The mixture was mixed for 30 minutes using a mortar or the like. The obtained mixture was baked at 1100 ° C. in a nitrogen atmosphere containing 2% by volume of hydrogen for 2 hours. Furthermore, the obtained compound was pulverized with a ball mill to obtain a target phosphor. And the PDP which formed the fluorescent substance layer using the blue fluorescent substance obtained in this way was created.

As a result of measuring the temperature dependence of the chromaticity of the PDP in blue display by the method of the example, CIE chromaticity coordinates (x, y) at room temperature indicate (0.160, 0.049), and 60 The chromaticity coordinate changes (Δx, Δy) at 0 ° C. were (0.003, 0.006). When the blue display of the front substrate at 60 ° C. and the blue display at room temperature were compared with the naked eye, the difference in color was clearly confirmed.

  As described above, according to the present invention, it is useful to improve the display quality of a PDP by using a blue phosphor with a small change in emission chromaticity due to a change in temperature for the PDP phosphor layer.

Sectional drawing which shows the principal part of the plasma display panel by one embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front substrate 2 Back substrate 3 Discharge space 4 Display electrode pair 5 Dielectric layer 6 Protective layer 7 Data electrode 8 Bulkhead 9 Phosphor layer

Claims (2)

In the plasma display panel having a phosphor layer made of a blue phosphor, the blue phosphor has a base metal ion having an ionic radius larger than that of the activator on a silicate phosphor containing Eu as an activator. A plasma display panel containing the plasma display panel. Formula _{lCaO · mM1O · nM2O · 2SiO 2} (M1 represents at least one selected from Sr and Ba, M2 is at least one selected from Mg and Zn, l and m are 0.1 or more 3.4 In the following, n is 0.5 or more and 2.5 or less, provided that 0.5 ≦ l + m ≦ 3.5.) And at least one selected from Eu and Mn as activators The plasma display panel according to claim 1, further comprising:

Images