JP2003132803A - Light emission device and display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a long service life for display devices and light emission devices. SOLUTION: In these display devices and light emission devices, a blue color phosphor (bivalent europium activated alkaline earth silicate phosphor) having high performance is used in a state of being excited by ultraviolet rays in a vacuum ultraviolet region or low velocity electron beams. The material has the following composition formula: (Ae)3-x(Ae')Si2O8:Eux (Here, Ae or Ae' is composed of at least a kind of an alkaline earth metal, and Ae is chosen from Sr, Ca and Ba, and also Ae' is chosen from Mg and Zn, in addition among them, Ae is desired to include Sr and Ae' to include Mg, and also x is a number in the following renge: 0.01<=x<=0.1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display and a field emission display provided with a fluorescent substance as a fluorescent film which emits light when excited by a rare gas resonance ultraviolet ray or a slow electron beam in a vacuum ultraviolet region (wavelength: 200 nm or less). The present invention relates to a light emitting device and a display device using the same.

[0002]

2. Description of the Related Art Along with the trend toward thinner display and light emitting devices, the performance of plasma display devices, liquid crystal display devices, and field emission display (FED) devices has been improved. The plasma display device has a fluorescent light arranged in the discharge space as an excitation source of ultraviolet rays (at 147 nm and 172 nm when xenon is used as a rare gas) generated in a negative glow region in a minute discharge space containing a rare gas. It is a method of displaying color by making the body emit light. Further, in the liquid crystal display device, a straight tube type white fluorescent lamp is currently used as a backlight, but there is also a demand for improving the brightness of the display screen and reducing mercury to the environment. Measures for solving these problems As a flat type rare gas discharge fluorescent lamp, a fluorescent substance for exciting a rare gas resonance line is used for this.

[0003]

The performance of plasma display devices, rare gas discharge light-emitting devices (fluorescent lamps, etc.), and field emission display (FED) devices largely depends on the performance of the phosphor. With regard to the current blue phosphor for PDP (BaMgAl10O17: Eu, hereinafter abbreviated as BAM), it is desired to prolong the life and improve the luminous efficiency.

[0004]

The present inventors have previously developed a divalent europium-activated alkaline earth silicate phosphor as a blue phosphor for electron beams [JP-A-64-6087, Kaihei 01-167394], but evaluation using ultraviolet rays in the vacuum ultraviolet region and slow electron beams has not been examined. Recently, the inventors of the present invention have found a composition having a good color tone and a high luminous efficiency under the excitation of ultraviolet rays in the vacuum ultraviolet region and low-speed electron beam, and completed the present invention.

The phosphor of the present invention is characterized by having the following composition formula.

(Ae) 3-x (Ae ') Si2O8: Eux However, Ae is at least one selected from Sr, Ca and Ba, and Ae' is at least one selected from Mg and Zn. It is a type of alkaline earth element. Further, in this, Ae is a composition containing Sr and Ba, and Ae
'Is a combination of Mg is preferable. Also, x is a number in the following range. 0.01 ≦ x ≦ 0.1 Further, the plasma display device, the rare gas discharge light emitting device and the field emission display (FED) device of the present invention are both display and light emitting devices provided with a phosphor film made of the above phosphor. .

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have developed a blue-emitting divalent europium-activated alkaline earth silicate phosphor with good color tone and high efficiency, and by using it as a blue component, It was possible to obtain a high-performance plasma display device, a rare gas discharge light-emitting device, and a field emission display (FED) device.

FIG. 1 shows Sr3− when the color difference between the isochromaticity coordinate values (U, V) of the fluorescent color and the NTSC standard blue point under the excitation of 147 nm vacuum ultraviolet ray is 100% of that of the current phosphor BAM. The Eu concentration dependence of the relative color difference of xMgSi2O8: Eux was shown. From this figure, the Eu concentration (x) is 0.01 ≦ x ≦ 0.
It is clear that the range is closer to the NTSC blue point than the current BAM phosphor and the color tone is good. In addition, the luminous efficiency was at the same level as BAM and had a long life. Less than,
An example of the present invention will be described.

The representative phosphor of the present invention is synthesized as follows. Examples of the phosphor raw material include alkaline earth carbonate compounds such as strontium carbonate, zinc compounds such as zinc carbonate, europium compounds such as europium fluoride, silicon compounds such as silicon oxide, and ammonium halides such as ammonium chloride. Using a compound, each of these raw materials is weighed and sampled according to the composition formula, and sufficiently mixed by a wet or dry method.
This mixture is filled in a heat-resistant container such as a fused alumina crucible and fired twice. The first firing is performed in air at 800 ° C, and the second firing is performed in a 5% hydrogen mixed nitrogen gas atmosphere at 125 ° C.
Bake at a temperature of 0 ° C. The fired product is pulverized, washed with water and dried to obtain the blue light emitting phosphor of the present invention. [Example 1] Table 1 shows the composition of the phosphors and the relative emission color difference.

[0010]

[Table 1] Of these, the phosphor of Sample 4 was synthesized as follows. That is,
The following raw materials, SrCO3: 4.385 g, MgCO3:
0.907 g, SiO2: 1.00 g, Eu2O3:
After sufficiently mixing 0.053 g and NH4Cl: 0.022 g, this mixture was filled in a heat-resistant container such as a fused alumina crucible and heated at 800 ° C. in air, and then at 1250 ° C. in a 5% hydrogen-mixed nitrogen gas atmosphere. Bake at temperature. The fired product was crushed, washed with water and dried to obtain a blue light emitting phosphor. When the color difference between the values (U, V) on the isochromaticity coordinates of the fluorescent color of the same phosphor under the excitation of 147 nm VUV and the NTSC standard blue point is 100% of that of the current phosphor BAM. The relative color difference of sample 4 is 80%. This is closer to the NTSC standard blue point than the current BAM, indicating that the color tone is good. Similarly, samples 1, 2, 3 and 5
Was synthesized. The relative color differences of these phosphors were 99, 86, 82 and 87%, showing good values.
FIG. 1 shows the above results as the Eu concentration (x) dependence of the relative color difference of the phosphor. As is clear from this figure, the effective range of Eu is 0.01 ≦ x ≦ 0.1. The emission brightness of the phosphor in this Eu concentration range is almost at the same level as BAM. [Example 2] Ca, Sr, Ba, and Mg shown in Table 2 were prepared by using the above-mentioned raw materials and following the same synthetic process.
Alternatively, phosphors (Samples 6 to 20) partially substituted with Zn were synthesized. It was found that each of these phosphors had a high emission brightness under the excitation of 147 nm ultraviolet light. Example 3 A plasma display panel (PDP) using the divalent europium-activated alkaline earth silicate phosphor (composition shown in Tables 1 and 2) according to the present invention as a blue phosphor constituting a blue phosphor film. Was produced.

[0011]

[Table 2] In the PDP of the surface discharge type color PDP as in this embodiment, for example, a negative voltage is applied to the display electrodes (generally called scan electrodes), and a positive voltage is applied to the address electrodes and the display electrodes (display electrodes are applied. Discharge is generated by applying a positive voltage to the display electrodes, and thereby wall charges are formed between the display electrodes to assist in initiating the discharge. In this state, when an appropriate reverse voltage is applied between the display electrodes, a discharge is generated in the discharge space between the electrodes via the dielectric (and the protective layer). . When the voltage applied to the display electrode and the display electrode is reversed after the discharge is completed, a new discharge is generated. By repeating this, discharge is continuously generated (this is called sustain discharge or display discharge).

The PDP of this embodiment has a rear substrate,
After forming an address electrode composed of silver or the like and a dielectric layer composed of a glass-based material, a partition material also composed of a glass-based material is thick-film printed, and using a blast mask, A partition is formed by removing the blast. Next, red, green, and blue phosphor layers are sequentially formed on the barrier ribs in a stripe shape so as to cover the groove surfaces between the barrier ribs.

Here, each phosphor layer corresponds to red, green and blue, and 40 parts by weight of red phosphor particles (60 parts by weight of vehicle),
35 parts by weight of green phosphor particles (65 parts by weight of vehicle) and 35 parts by weight of blue phosphor particles (65 parts by weight of vehicle) are mixed with a vehicle to form a phosphor paste, which is applied by screen printing and then dried and baked. Is formed by evaporating volatile components in the phosphor paste and removing organic substances by burning. The phosphor layer used in the present embodiment is composed of each phosphor particle having a median particle diameter of 3 μm.

The material of each phosphor is (Y, G
d) It is a mixture of BO3: Eu phosphor and Y2O3: Eu phosphor 1: 1, and the green phosphor is Zn2SiO4: Mn phosphor.

Next, the front substrate on which the display electrodes, bus electrodes, dielectric layer, and protective layer are formed and the rear substrate are frit-sealed, the interior of the panel is evacuated, and then a discharge gas is injected to seal it. The PDP of this embodiment has a size of 3 type and a pitch of one pixel is 1000 μm × 1000 μm. Next, using each phosphor formed in Examples 1 and 2, red,
The same material was used for the green phosphor, and a plasma display device in which each phosphor layer 25 was filled was manufactured, and the initial luminance and life characteristics were examined. This panel had a good color tone, high brightness and a long life as compared with the conventional product produced by replacing only the blue phosphor with a divalent europium-activated barium-magnesium aluminate phosphor. Regarding the initial luminance, the relative emission intensities described for each of the phosphors in Table 2 were obtained, and in all cases, the results were equal to or higher than those of the divalent europium-activated barium-magnesium aluminate phosphor as a comparative sample. Also in terms of life performance, all phosphors (all compositions shown in Table 1 and Table 2) showed results exceeding that of the comparative phosphor. Further, in this example, detailed examination results are not shown for the red and green phosphors, but the PDP can be similarly prepared with the phosphors having the respective compositions shown below.

In the red phosphor, (Y, Gd) BO3: Eu, (Y, Gd) 2O3:
It is possible to include one or more phosphors of Eu, (Y, Gd) (P, V) O4: Eu. The green phosphor is Zn2SiO4: M.
n, (Y, Gd, Sc) 2SiO5: Tb, (Y, Gd) 3 (Al, Ga) 5O12: Tb, (Y, Gd)
It is possible to include one or more phosphors selected from the group of 3 (Al, Ga) 5O12: Ce, (Y, Gd) B3O6: Tb, (Y, Gd) PO4: Tb. Furthermore, combinations with phosphors not shown here are also applicable. [Example 4] A divalent unit according to the present invention as a blue phosphor color
Ropium-activated alkaline earth silicate phosphor (composition shown in Table 1), divalent manganese-activated zinc silicate phosphor as green phosphor, and trivalent europium-activated yttrium oxide as red phosphor. Noble gas using gadolinium phosphor
(Xenon gas) discharge white fluorescent lamp was manufactured. This lamp had a high luminous efficiency and a long life as compared with the conventional product produced by replacing only the blue phosphor with a divalent europium-activated barium-magnesium aluminate phosphor. Example 5 The divalent europium-activated alkaline earth silicate phosphor according to the present invention (composition shown in Table 2) was used as the blue phosphor, and the divalent manganese-activated zinc silicate phosphor was used as the green phosphor. Then, a trivalent europium-activated yttrium-gadolinium oxide phosphor was used as the red phosphor to manufacture a flat rare gas (xenon gas) discharge white fluorescent lamp. This lamp had a high luminous efficiency and a long life as compared with the conventional product produced by replacing only the blue phosphor with a divalent europium-activated barium-magnesium aluminate phosphor. Example 6 Here, first, a uniform transparent electrode was formed on the inner surface of the glass substrate on which the fluorescent film was formed. Next, the divalent europium-activated alkaline earth silicate phosphor according to the present invention (composition shown in Table 1 and Table 2) was used as the blue phosphor forming the blue phosphor film, and the green phosphor forming the green phosphor film. A divalent manganese-activated zinc silicate phosphor was formed as a phosphor, and a trivalent europium-activated yttrium-gadolinium oxide phosphor was sequentially formed as a red phosphor forming a red phosphor layer. This glass substrate and another glass substrate in which a minute electron beam source was made were put together and sealed, and after evacuation, a 10-inch field emission display (FED) panel was manufactured. This panel exhibited higher efficiency and longer life than the FED panel manufactured by replacing the conventional blue phosphor only with the divalent europium-activated barium-magnesium aluminate phosphor. It was confirmed that a good display quality was obtained when a display panel was constructed using this panel and used as a display system for televisions, videos, automobiles and the like. As described above, the blue phosphor [divalent europium-activated alkaline earth silicate phosphor] having high efficiency under the vacuum ultraviolet region ultraviolet light and low-speed electron beam excitation is used as a rare gas discharge display / light emitting device or a field emission type device. Display (F
Higher efficiency could be realized by using it in the ED) device.

[0017]

The light emitting device and the display device of the present invention have high brightness and long life.

[Brief description of drawings]

FIG. 1 shows Sr3− when the color difference between the isochromaticity coordinate values (U, V) of the fluorescent color under the excitation of 147 nm VUV and the NTSC standard blue point is 100% of that of the current phosphor BAM.
xMgSi2O8: Eu concentration of relative color difference of Eux (x)
It is the figure which showed the dependency.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09K 11/59 CPR C09K 11/59 CPR CPW CPW CQA CQA 11/78 11/78 11/79 11/79 11/80 11 / 80 11/81 11/81 11/83 11/83 (72) Inventor Nobuichiro Okazaki 7-1-1, Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory F-term (reference) 4H001 CA04 CA05 XA05 XA08 XA12 XA13 XA14 XA15 XA20 XA21 XA23 XA30 XA31 XA38 XA39 XA56 XA64 YA25 YA58 YA63 YA65 5C040 FA10 GG08 JA12 KB03 MA03 MA05

Claims (10)

[Claims] 1. A light emitting device comprising a phosphor film containing a blue light emitting divalent europium activated alkaline earth silicate phosphor represented by the following chemical formula. (Ae) 3 (Ae ') Si2O8: Eu (where Ae is at least one alkaline earth element selected from Sr, Ca and Ba.
e'is at least one kind of alkaline earth element selected from Mg or Zn. ) 2. The light emitting device according to claim 1, wherein the blue light emitting divalent europium-activated alkaline earth silicate phosphor is represented by the following composition formula. ((Sr1-y, Bay) 3-xMgSi2O8: Eux, where y is 0≤y≤1.) 3. In the composition formula of the blue-emitting divalent europium-activated alkaline earth silicate phosphor, x is 0.01 ≦.
3. The light emitting device according to claim 1, wherein x ≦ 0.1. 4. The display device comprises a pair of substrates arranged to face each other with a gap, a discharge gas space formed between the pair of substrates and filled with a gas for generating ultraviolet rays by electric discharge, A plasma display having an electrode formed on each of opposing surfaces of a pair of substrates and a phosphor layer formed on a surface of one of the pair of substrates in contact with the discharge gas space. apparatus. 5. The red phosphor layer among the phosphor layers is (Y, G
d) A plasma display having at least one phosphor selected from BO3: Eu, (Y, Gd) 2O3: Eu, (Y, Gd) (P, V) O4: Eu. The light emitting device according to claim 4. 6. The green phosphor layer among the phosphor layers is Zn2SiO4:
Mn, (Y, Gd, Sc) 2SiO5: Tb, (Y, Gd) 3 (Al, Ga) 5O12: Tb, (Y, G
d) A plasma display having at least one phosphor selected from the group consisting of 3 (Al, Ga) 5O12: Ce, (Y, Gd) B3O6: Tb and (Y, Gd) PO4: Tb. The light emitting device according to claim 4, wherein the light emitting device is provided. 7. A display device comprising a light-emitting device having a phosphor film containing a blue-emitting divalent europium-activated alkaline earth silicate phosphor represented by the following chemical formula. (Ae) 3 (Ae ') Si2O8: Eu (where Ae is at least one alkaline earth element selected from Sr, Ca and Ba.
e'is at least one kind of alkaline earth element selected from Mg or Zn. ) 8. A flat rare gas discharge fluorescent lamp provided with a fluorescent film containing a blue-emitting divalent europium-activated alkaline earth silicate phosphor represented by the following chemical formula: Display device. (Ae) 3 (Ae ') Si2O8: Eu (where Ae is at least one alkaline earth element selected from Sr, Ca and Ba.
e'is at least one kind of alkaline earth element selected from Mg or Zn. ) 9. A display characterized by using a three-wavelength white fluorescent lamp provided with a fluorescent film containing a blue-emitting divalent europium-activated alkaline earth silicate phosphor represented by the following chemical formula. apparatus. (Ae) 3 (Ae ') Si2O8: Eu (where Ae is at least one alkaline earth element selected from Sr, Ca and Ba.
e'is at least one kind of alkaline earth element selected from Mg or Zn. ) 10. A blue light emitting divalent unit represented by the following chemical formula:
A display device comprising a field emission display device having a phosphor film containing a rhodium-activated alkaline earth silicate phosphor. (Ae) 3 (Ae ') Si2O8: Eu (where Ae is at least one alkaline earth element selected from Sr, Ca and Ba.
e'is at least one kind of alkaline earth element selected from Mg or Zn. )