JP2001172626A - Display and light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a Tb-activated rare earth alumino-borate fluorescent substance having a high efficiency under excitation with ultraviolet rays within the vacuum ultraviolet region (wavelength: <=200 nm) and low-energy electron beams. SOLUTION: This fluorescent substance comprises the general compositional formula LnAl3B4O12:Tb (wherein Ln is at least one kind of element selected from La, Y, Gd, Lu and Sc), more preferably the compositional formula (Y1-x-yGdxTby)Al3B4O12 (wherein 0<=x<=0.85; and 0.15<=y<=0.65).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display device provided with a phosphor which emits green 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) as a phosphor film, and a plasma display device. The present invention relates to a gas discharge light emitting device and a field emission display (FED) device.

[0002]

2. Description of the Related Art As display and light-emitting devices become thinner, the performance of plasma display devices, liquid crystal display devices, and field emission display (FED) devices is increasing.

A plasma display device uses ultraviolet light (in the case of using xenon as a rare gas, its resonance line is at 147 nm) generated in a negative glow region in a minute discharge space containing a rare gas as an excitation source, and emits light in the discharge space. In this method, color display is performed by emitting light from the phosphors arranged in the light emitting device.

In a liquid crystal display device, it is not possible to cope with the problem by simply reducing the diameter of a straight tube type white fluorescent lamp mainly used for a backlight at present, and there is also a demand for reducing mercury in the environment. As a measure to solve these problems, a flat type rare gas discharge fluorescent lamp has been developed,
A phosphor for exciting a rare gas resonance line is used. On the other hand, for a field emission display (FED), a phosphor for exciting a slow electron beam is used.

[0005]

The performance of plasma display devices, rare gas discharge light emitting devices (such as fluorescent lamps) and field emission display (FED) devices largely depends on the performance of phosphors. In particular, it is desired to improve the efficiency of the green phosphor (typically, Zn ₂ SiO ₄ : Mn).

[0006]

The luminous efficiency of Tb-activated rare earth alumino-borate under high-voltage electron beam excitation has been reported by the Philips Research Report (Ph).
ilips Res. Rep., vol. 22, p. 481-67). The present inventors have studied the types of rare earth elements constituting the base of the rare earth alumino-borate phosphor, the optimum Tb concentration, and the synthesis conditions. As a result, the green light with high luminous efficiency under vacuum ultraviolet region ultraviolet light and low-speed electron beam excitation was obtained. A phosphor was obtained, and the present invention has been achieved.

The phosphor of the present invention has a general composition formula of LnAl ₃ B ₄ O ₁₂ : Tb (where Ln is La, Y, Gd, Lu and S
c) is a green light-emitting phosphor that can be represented by at least one element selected from c), and is preferably a phosphor having the following composition.

[0008] _{(Y 1-xy Gd x Tb} y) Al 3 B 4 O 12 ( provided that, 0 ≦ x ≦ 0.85,0.15 ≦ y ≦ 0.6
5) The plasma display device, the rare gas discharge light emitting device, and the field emission display (FED) device of the present invention are all display and light emitting devices provided with a phosphor film made of the above phosphor.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present inventors have developed a high-efficiency Tb-activated alumino-borate phosphor and used it as a green component to provide a high-efficiency plasma display device, a rare gas discharge light-emitting device and an electric field. An emissive display (FED) device could be obtained.

[0010] Table 1 in _{Ln 1-y Tb y Al 3} B 4 O 12, picks up the Y and Gd as a typical rare earth elements, the type and Tb content of the rare earth element (Ln) (y)
7 is a table showing relative luminescence intensities under 147 nm xenon resonance line excitation in the case of changing.

As is clear from this table, when the rare earth element is Y or Gd, a phosphor having a higher emission intensity than Zn ₂ SiO ₄ : Mn, which is generally used as a green phosphor, can be obtained. Was.

[0012] Figure 1 is a _{Y 1-y Tb y Al 3} B 4 O 12 147nm
The Tb concentration dependence of the relative luminescence intensity under the xenon resonance line excitation was shown. As is clear from this figure, the Tb concentration y =
In the range of 0.15 to 0.65, a phosphor having a higher emission intensity than that of Zn ₂ SiO ₄ : Mn could be obtained.

The representative phosphor of the present invention is synthesized as follows. First, as a phosphor raw material, a rare earth compound such as an oxide, a terbium compound such as terbium oxide, an aluminum compound such as aluminum oxide and aluminum hydroxide, and a boron compound such as boron oxide and boron hydroxide are used. Weigh and collect according to the above, and mix well by wet or dry method. In addition, you may use a coprecipitation raw material as a rare earth raw material.

The mixture is filled in a heat-resistant container such as a platinum crucible or a fused alumina crucible and gradually heated in a neutral atmosphere or an oxidizing atmosphere such as air (heating rate: 200 ° C./h or less, preferably about 20 ° C./h). h) 1000 to 1200
Firing at a temperature of ° C. After pulverizing this calcined product, 1: 1 HC
After washing with an aqueous solution, washing with water and drying are performed, and re-firing at the same temperature is performed to obtain the green light emitting phosphor of the present invention.

Example 1 Table 1 shows the composition of the phosphor and the relative luminous intensity. Among them, the phosphor of Sample 2 was synthesized as follows. That is, as a raw material was weighed _{Y 2 O 3 ............ 7.90g Tb 4} O 7 ......... 5.61g Al 2 O 3 ...... 15.29g B 2 O 3 ......... 20.89g, sufficiently uniform After that, the mixture was filled in an alumina crucible, gradually heated to 1100 ° C. in the air at a rate of temperature increase of 30 ° C./h, and calcined at the same temperature for 2 hours. The obtained fired product was pulverized, washed with 1: 1 HCl aqueous solution, washed with water, and dried to obtain a phosphor.

Xenon resonance line (147 nm) of this phosphor
The luminescence intensity under excitation was 110% higher than that of Zn ₂ SiO ₄ : Mn (comparative sample), indicating high efficiency.

In the same manner, the phosphors of Samples 1 and 3 in Table 1 were synthesized. Xenon resonance lines (147) of these phosphors
nm) Emission intensity under excitation is 101% and 103%, respectively.
It showed a high value.

FIG. 1 shows the above results as the dependence of the emission intensity of the phosphor on the Tb content (y). As is clear from this figure, the effective range of Tb is 0.15 ≦ y ≦
It turns out that it is 0.65.

[0019]

[Table 1]

Example 2 Phosphors (Sample 4) listed in Table 1 using the raw materials described above and following a similar synthesis process
Was synthesized. Xenon resonance line (147 nm) of this phosphor
The emission intensity under the excitation showed a high value of 108%.

Example 3 Using the raw materials described above and following the same synthesis process, the phosphors listed in Table 1 (sample 5,
6, 7, 8 and 9) were synthesized. The emission intensity of this phosphor under xenon resonance line (147 nm) excitation was 1 for each.
The values were as high as 06, 106, 103, 104 and 103%.

Example 4 A divalent Eu-activated barium magnesium aluminate phosphor as a blue phosphor, Y _0.7 Tb _0.3 Al ₃ B ₄ O _{12 according} to the present invention as a green phosphor,
A rare gas (xenon gas) discharge white fluorescent lamp was manufactured using a trivalent Eu-activated yttrium oxide phosphor as a red phosphor. This lamp uses only green phosphor as divalent Mn.
The luminous efficiency was higher than that of a conventional product manufactured in place of the activated zinc silicate phosphor.

Example 5 A divalent Eu-activated barium magnesium aluminate phosphor as a blue phosphor, Y _0.7 Tb _0.3 Al ₃ B ₄ O _{12 according} to the present invention as a green phosphor,
The trivalent Eu activated yttrium borate is used as the red phosphor.
A flat rare gas (xenon gas) discharge white fluorescent lamp was fabricated using a gadolinium phosphor. This lamp had higher luminous efficiency than a conventional lamp manufactured by replacing only the green phosphor with a divalent Mn-activated zinc silicate phosphor.

Example 6 A divalent Eu-activated barium magnesium aluminate phosphor is used as a blue phosphor constituting a blue phosphor film, and Y _0.7 Tb _0.3 Al of the present invention is used as a green phosphor constituting a green phosphor film. _A plasma display panel was manufactured using ₃ B ₄ O ₁₂ and a trivalent Eu-activated yttrium / gadolinium borate phosphor as a red phosphor constituting a red phosphor film. This panel had higher luminous efficiency than a conventional product manufactured by replacing only the green phosphor with a divalent Mn-activated zinc silicate phosphor.

Embodiment 7 In this embodiment, first, a uniform transparent electrode was formed on the inner surface of a glass substrate on which a fluorescent film was formed. Next, a bivalent Eu-activated barium magnesium aluminate phosphor as a blue phosphor constituting the blue phosphor film,
As the green phosphor constituting the green phosphor film, Y _0.7 of the present invention is used.
Tb _0.3 Al ₃ B ₄ O ₁₂ and a trivalent Eu-activated yttrium oxide phosphor as a red phosphor constituting the red phosphor film were sequentially formed.

This glass substrate and another glass substrate formed with a fine electron beam source were sealed together, and after evacuation, a 10-inch field emission display (FED) panel was manufactured.

This panel exhibited higher luminance characteristics than the conventional FED panel. Using this panel, a display panel was constructed and used as a display system for televisions, videos, automobiles, etc., and it was confirmed that good display quality was obtained.

[0028]

The green light-emitting phosphor of the present invention and the display and light-emitting device using the same have high luminous efficiency and high performance characteristics.

[Brief description of the drawings]

[1] the composition formula Y _1-y Tb _y Al ₃ characteristic diagram showing a B ₄ Tb content dependence of the relative light emission intensity of O _12.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01J 29/20 H01J 29/20 31/12 31/12 C 61/44 61/44 N (72) Inventor Oka ▲ Saki ▼ Nobuichiro 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi Ltd. 4H001 CA04 CA05 CA07 XA05 XA08 XA12 XA13 XA14 XA21 XA30 XA39 XA56 XA57 XA64 XA71 YA25 5C036EE EF01 EF06 EF09 EG36 EH12 5C040 GG08 MA03 5C043 AA02 CC09 CC16 CD08 DD28 EA19 EB04 EC06 EC17 5G435 AA00 BB01 BB06 EE29 HH06

Claims (6)

[Claims] 1. A display / light-emitting device comprising a phosphor film containing a green-emitting rare-earth alumino-borate phosphor represented by the following composition formula: LnAl ₃ B ₄ O ₁₂ : Tb (where Ln is at least one element selected from La, Y, Gd, Lu and Sc) 2. A display / light emitting device according to claim 1, wherein said rare earth alumino-borate phosphor is preferably a green phosphor represented by the following composition formula. _{(Y 1-xy Gd x Tb} y) Al 3 B 4 O 12 ( provided that, 0 ≦ x ≦ 0.85,0.15 ≦ y ≦ 0.65
Is) 3. The phosphor of claim 1 or 2, wherein said phosphor is a green phosphor film, a divalent manganese-activated barium-magnesium aluminate phosphor, and a divalent manganese-activated zinc silicate phosphor. A plasma display device comprising a plasma panel having a phosphor film made of at least one kind of phosphor selected from phosphors. 4. A flat rare gas discharge fluorescent lamp comprising a phosphor film comprising the green phosphor of claim 1 as a green component. 5. A three-wavelength rare gas discharge white fluorescent lamp having a phosphor film comprising the green phosphor of claim 1 or 2 as a green component. 6. A field emission display having a phosphor film comprising the green phosphor of claim 1 or 2 as a green component.