JP2004176010A - Light-emitting device and display using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blue color phosphor suppressing light-emitting intensity reduction during a process for producing a light-emitting device and also in driving the light-emitting device. <P>SOLUTION: This light-emitting device is equipped with a fluorescent film containing a blue color-emitting europium-activated alkaline earth silicate phosphor expressed by (Ae)<SB>a-d</SB>(Be)Si<SB>b</SB>O<SB>c</SB>:Eu<SB>d</SB>[wherein, Ae is at least 1 kind selected from Sr, Ca and Ba; Be is at least one kind selected from Mg and Zn; (a), (b), (c) are each a=1, b=1, c=4; a=1, b=2, c=6; a=2, b=2, c=7; a=3, b=2, c=8; and (d) is 0.01≤d≤0.1]. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flat rare gas discharge fluorescent lamp, a plasma display, a three-wavelength white fluorescent lamp, and a field emission display each having a fluorescent film excited by an ultraviolet ray, a vacuum ultraviolet ray, and an electron beam as a fluorescent film, The present invention relates to a light emitting device and a display device using the same.
[0002]
[Prior art]
The performance of various light-emitting devices and display devices typified by flat-type rare gas discharge fluorescent lamps, plasma displays, three-wavelength white fluorescent lamps, and field emission displays largely depends on the performance of the phosphor used. . In a plasma display (PDP), an aluminate phosphor BaMgAl10O17: Eu (often called a BAM phosphor) has been generally used as a blue phosphor. However, there is a problem that the emission intensity is significantly reduced during the panel manufacturing process and during panel driving [Material Integration Vol. 14, No. 9 (2001) p. 18].
[0003]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a blue phosphor which suppresses a decrease in phosphor emission intensity when the light emitting device is manufactured and when the light emitting device is driven.
[0004]
[Means for Solving the Problems]
The inventors have studied the blue phosphor, and as a result, by using a silicate blue phosphor characterized by having a composition represented by the following chemical formula, a decrease in emission intensity during a manufacturing process or the like is suppressed. I found that.
_{(Ae) a-d (Be} ) Si b O c: Eu d
(However, Ae is at least one kind selected from Sr, Ca and Ba, Be is at least one kind selected from Mg or Zn, and the above a, b and c are a = 1, b = 1 and c = 4 Or a = 1, b = 2, c = 6 or a = 2, b = 2, c = 7 or a = 3, b = 2, c = 8, and d is 0.01 ≦ d ≦ 0.1 Is.)
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
A BAM phosphor generally used for a plasma display has a layered structure composed of spinel blocks and a conductive layer made of oxygen and Ba (or Eu) that connects the spinel blocks.
[0006]
For example, in a PDP manufacturing process, when a mixture of a BAM phosphor and a vehicle (referred to as a phosphor paste) is heated, atoms in the conductive layer change positions in the crystal, causing crystal defects, which cause light emission. This is considered to be one of the causes of the decrease in strength.
[0007]
The present invention, formula _{(Ae) a-d (Be} ) Si b O c: Eu d ( provided that at least one Ae is at least one selected from Sr, Ca and Ba, Be is selected from Mg or Zn Where a = 1, b = 1, c = 4 or a = 1, b = 2, c = 6 or a = 2, b = 2, c = 7 or a = 3 , B = 2, c = 8, and d satisfies 0.01 ≦ d ≦ 0.1). The phosphor film contains a blue-emitting divalent europium-activated alkaline earth silicate phosphor represented by the following formula: And a display device including the light emitting device.
[0008]
In the blue phosphor of the present invention, the emission intensity decreases less than the BAM phosphor. Although the detailed mechanism is still unknown, it is considered that one reason is that the crystal structure is simpler than that of the BAM phosphor.
[0009]
The phosphor of the present invention can be synthesized by a conventionally used method. A predetermined amount of each raw material (carbonate, oxide, etc.) and, if necessary, a reaction accelerator are blended and mixed. The mixture is fired for several hours in an air or oxidizing atmosphere in a crucible made of alumina (the firing temperature is 1000 to 1300 ° C.). After pulverizing the fired product, it is fired in a reducing atmosphere for several hours (the firing temperature is 1000 to 1300 ° C.). Thereafter, if necessary, the particle size is adjusted through a washing and pulverizing process.
[0010]
The blue phosphor of the present invention produced in this manner exhibited good characteristics in which a decrease in light emission intensity during the manufacturing process and panel driving was suppressed as compared with the BAM phosphor.
[0011]
Examples of the present invention will be described below, but the present invention is not limited by these examples.
(Example 1)
As raw materials, BaCO ₃ (2.98 mol%) [0 ≦ x ≦ 1], SrCO ₃ (2.98 (1-x) mol%), MgCO ₃ (1 mol%), SiO ₂ (2 mol%), Eu ₂ O ₃ (0.01 mol%) was weighed and mixed, and the obtained mixture was fired in an alumina crucible in an air atmosphere at 1300 ° C. for 3 hours. After pulverized, the fired product was fired at 1300 ° C. for 3 hours in a reducing atmosphere. The baked material is pulverized by a ball mill, washed with water, classified, and dried to give a phosphor represented by (Ba _x Sr _1-x ) _2.98 MgSi ₂ O ₈ : Eu _0.02 [0 ≦ x ≦ 1]. Got.
[0012]
40 parts by weight of the present phosphor and 60 parts by weight of a vehicle are mixed to form a phosphor paste, which is applied on a glass substrate by screen printing, and the paste is dried and baked to remove volatile components in the paste and remove organic substances by burning. A body membrane was formed.
[0013]
The phosphor was peeled off from the glass substrate to produce a paste fired powder, and the emission intensity (A ₁ ) when excited by an excimer lamp (center wavelength: 146 nm) was measured. At this time, the emission intensity (A ₀ ) of the original phosphor powder that was not printed and fired was measured. The emission intensity maintenance ratio (A = A ₁ / A ₀ × 100) was used as an index indicating deterioration during the paste firing process. For comparison, the same measurement was performed on a BAM phosphor generally used as a blue phosphor.
[0014]
FIG. 1 shows the emission intensity / luminance maintenance ratio (A). According to the invention _{(Ba x Sr 1-x)} 3-a MgSi 2 O 8: Eu a phosphor [0 ≦ x ≦ 0.1 or 0.65 ≦ x ≦ 1] is at the paste firing than BAM phosphors It was shown that the luminous intensity maintenance ratio was large, and that it had good characteristics in which deterioration was suppressed.
(Example 2)
A PDP was manufactured using the phosphor according to the present invention, and the drive deterioration characteristics were measured. FIG. 2 is a schematic diagram of a display panel in a PDP. In FIG. 2, 1 is a front substrate, 2 is a back substrate, 3 is an address electrode, 4 is a partition, 5 is a phosphor layer, 6 is a back plate glass, 7 is a dielectric layer, 8 is a front plate glass, 9 is a dielectric layer, Reference numeral 10 denotes a protective film, and 11 denotes a sustain electrode.
[0015]
The PDP of the present embodiment is configured by integrating a front substrate 1 and a rear substrate 2 into one body. After the address electrodes 3 and the barrier ribs 4 were formed on the rear substrate 2, the Ba ₃ MgSi ₂ O ₈ : Eu _0.02 phosphor layer 5 was formed between the barrier ribs 4 in the following procedure.
[0016]
That is, 40 parts by weight of the phosphor and 60 parts by weight of the vehicle are mixed to form a phosphor paste, which is applied by screen printing, and the volatile components in the paste are removed and the organic substances are removed by burning by a drying and baking process. Formed.
[0017]
The back substrate 2 was bonded to the front plate 1 to produce a plasma display panel in which a discharge gas was sealed, and the driving time characteristics of the light emission intensity were measured.
[0018]
The light emission intensity (B ₀ ) at the start of panel driving and the light emission intensity (B ₁ ) at 500 hours after the panel driving were measured, and the light emission intensity maintenance ratio (B = B ₁ / B ₀ ×) was used as an index indicating deterioration due to panel driving. 100) was used. For comparison, the same measurement was performed on a BAM phosphor generally used as a blue phosphor.
[0019]
FIG. 3 shows the result of the measurement. According to the invention _{(Ba x Sr 1-x)} 3-a MgSi 2 O 8: Eu a phosphor [0 ≦ x ≦ 0.1 or 0.65 ≦ x ≦ 1] is at panel driving than BAM phosphors It was shown that the luminous intensity maintenance ratio was large, and that it had good characteristics in which deterioration was suppressed.
[0020]
【The invention's effect】
According to the present invention, it is possible to realize a light emitting device and a display device which are excellent in life characteristics with little change in light emission intensity when driving a panel.
[Brief description of the drawings]
FIG. 1 is a measurement diagram showing a light emission intensity maintenance ratio before and after paste firing in a phosphor of the present invention.
FIG. 2 is a schematic perspective view showing the structure of a plasma display panel.
FIG. 3 is a measurement diagram showing a light emission intensity maintenance ratio of the phosphor of the present invention when the plasma display panel is driven for 500 hours.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Front board, 2 ... Back board, 3 ... Address electrode, 4 ... Partition, 5 ... Phosphor layer, 6 ... Back glass, 7 ... Dielectric layer, 8 ... Front glass, 9 ... Dielectric layer, 10 ... Protection Membrane, 11 ... Sustain electrode.

Claims (7)

Following blue emitting divalent europium activated alkaline earth silicate phosphor layer containing a phosphor represented by the chemical formula _{(Ae) a-d (Be} ) Si b O c: Eu d
(However, Ae is at least one kind selected from Sr, Ca and Ba, Be is at least one kind selected from Mg or Zn, and the above a, b and c are a = 1, b = 1 and c = 4 Or a = 1, b = 2, c = 6 or a = 2, b = 2, c = 7 or a = 3, b = 2, c = 8, and d is 0.01 ≦ d ≦ 0.1 ). Fluorescent film _{(Ba x Sr 1-x)} 3-d MgSi 2 O 8 containing a blue emitting divalent europium activated alkaline earth silicate phosphor represented by the following chemical formula: Eu _d
(Where 0 ≦ x ≦ 0.1 or 0.65 ≦ x ≦ 1, 0.01 ≦ d ≦ 0.1). 3. The light emitting device according to claim 1, wherein the light emitting device has a flat type rare gas discharge fluorescent lamp structure. 3. The light emitting device according to claim 1, wherein the light emitting device has a plasma display structure. 3. The light emitting device according to claim 1, wherein the light emitting device has a three-wavelength white fluorescent lamp structure. 3. The light emitting device according to claim 1, wherein the light emitting device has a field emission display structure. A display device comprising the light emitting device according to claim 1.

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