White light-emitting device and manufacturing method thereof, and backlight and liquid crystal display device using the same
View Patent ↗A white light-emitting device 1 includes a semiconductor light-emitting element 2 emitting ultraviolet light or violet light, and a light-emitting unit 10 which includes three or more kinds of visible light-emitting phosphors 9 and emits white light when excited by the light from the semiconductor light-emitting element 2 . The emission spectrum of the light-emitting unit 10 has peaks in a blue region of not less than 440 nm nor more than 460 nm, a green region of not less than 510 nm nor more than 530 nm, and a red region of not less than 620 nm nor more than 640 nm, and the three or more kinds of visible light-emitting phosphors 9 are bound together with a binder in advance.
1. A white light-emitting device, comprising:
a semiconductor light-emitting element emitting ultraviolet light or violet light; and
a light-emitting unit, which is excited by the light from the semiconductor light-emitting element to emit white light, including three or more kinds of visible light-emitting phosphors, including a blue light-emitting phosphor, a green light-emitting phosphor, and a red light-emitting phosphor,
wherein emission spectrum of the light-emitting unit has peaks in a blue region of not less than 440 nm nor more than 460 nm, a green region of not less than 510 nm nor more than 530 nm, and a red region of not less than 620 nm nor more than 640 nm, and the three or more kinds of visible light-emitting phosphors are bound together with a binder in advance,
wherein the blue light-emitting phosphor comprises a europium-activated halo-phosphate phosphor having a composition which is represented by the general formula:
(Sr 1-x-y Ba x Ca y Eu z ) 10 (PO 4 ) 6 .Cl 2
(where, x, y and z are numbers satisfying x<0.2, y<0.1, 0.005<z<0.1),
wherein the green light-emitting phosphor comprises a europium and manganese-activated aluminate phosphor having a composition which is represented by the general formula:
(Ba 1-x-y-z Sr x Ca y Eu z )(Mg 1-u Mn u )Al 10 O 17
(where, x, y and z are numbers satisfying x<0.5, y<0.1, 0.15<z<0.4, 0.3<u<0.6),
wherein the red light-emitting phosphor comprises a europium-activated lanthanum oxysulfide phosphor having a composition which is represented by the general formula:
(La 1-x-y Eu x M y ) 2 O 2 S
(where, M shows at least one of element selected from Sb and Sn, and x and y are numbers satisfying 0.01<x<0.15, y<0.03),
wherein the visible light-emitting phosphors include 10 mass % to 30 mass % of the blue light-emitting phosphor, 10 mass % to 30 mass % of the green light-emitting phosphor, and 50 mass % to 80 mass % of the red light-emitting phosphor.
2. The white light-emitting device as set forth in claim 1 ,
wherein a half width of each of the peaks in the blue region, the green region and the red region is 50 nm or less.
3. The white light-emitting device as set forth in claim 1 ,
wherein the semiconductor light-emitting element has a peak value of an emission wavelength of not less than 370 nm nor more than 410 nm.
4. The white light-emitting device as set forth in claim 1 ,
wherein the semiconductor light-emitting element includes a light-emitting diode or a laser diode.
5. The white light-emitting device as set forth in claim 1 ,
wherein the light-emitting unit has a resin layer in which the bound three or more kinds of visible light-emitting phosphors are dispersed.
6. The white light-emitting device as set forth in claim 1 ,
wherein both an average primary particle size before bonding and an average secondary particle size after bonding of the three or more kinds of visible light-emitting phosphors are 7 μm or more.
7. A method of manufacturing a white light-emitting device, comprising:
preparing three or more kinds of visible light-emitting phosphors including a blue light-emitting phosphor, a green light-emitting phosphor, and a red light-emitting phosphor, adjusted to have emission spectrum of white light emission exhibiting peaks in a blue region of not less than 440 nm nor more than 460 nm, a green region of not less than 510 nm nor more than 530 nm, and a red region of not less than 620 nm nor more than 640 nm;
binding the three or more kinds of visible light-emitting phosphors with a binder; and
forming a light-emitting unit including the bound three or more kinds of visible light-emitting phosphors, in a light-emitting direction of a semiconductor light-emitting element emitting ultraviolet light or violet light,
wherein the blue light-emitting phosphor comprises a europium-activated halo-phosphate phosphor having a composition which is represented by the general formula:
(Sr 1-x-y Ba x Ca y Eu z ) 10 (PO 4 ) 6 .Cl 2
(where, x, y and z are numbers satisfying x<0.2, y<0.1, 0.005<z<0.1),
wherein the green light-emitting phosphor comprises a europium and manganese-activated aluminate phosphor having a composition which is represented by the general formula:
(Ba 1-x-y-z Sr x Ca y Eu z )(Mg 1-u Mn u )Al 10 O 17
(where, x, y and z are numbers satisfying x<0.5, y<0.1, 0.15<z<0.4, 0.3<u<0.6),
wherein the red light-emitting phosphor comprises a europium-activated lanthanum oxysulfide phosphor having a composition which is represented by the general formula:
(La 1-x-y Eu x M y ) 2 O 2 S
(where, M shows at least one of element selected from Sb and Sn, and x and y are numbers satisfying 0.01<x<0.15, y<0.03),
wherein the visible light-emitting phosphors include 10 mass % to 30 mass % of the blue light-emitting phosphor, 10 mass % to 30 mass % of the green light-emitting phosphor, and 50 mass % to 80 mass % of the red light-emitting phosphor.
8. The method of manufacturing a white light-emitting device as set forth in claim 7 ,
wherein a half width of each of the peaks in the blue region, the green region and the red region is 50 nm or less.
9. The method of manufacturing a white light-emitting device as set forth in claim 7 ,
wherein the bound three or more kinds of visible light-emitting phosphors are dispersed in a resin to form the light-emitting unit.
10. A backlight, comprising:
a substrate; and
a white light-emitting device as set forth in claim 1 mounted on the substrate.
11. The backlight as set forth in claim 10 , further comprising:
a plurality of the white light-emitting devices arranged in line or in matrix on the substrate.
12. A liquid crystal display device comprising:
a backlight as set forth in claim 10 ; and
a liquid crystal display unit disposed on a light-emitting surface side of the backlight.
13. The liquid crystal display device as set forth in claim 12 ,
wherein the backlight comprises a plurality of the white light-emitting devices arranged in matrix and is disposed directly below the liquid crystal display unit.
14. The liquid crystal display device as set forth in claim 12 ,
wherein the liquid crystal display unit is disposed on an optical waveguide, and the backlight comprises a plurality of the white light-emitting devices arranged in line and is disposed on one end portion of the optical waveguide.
15. A white light-emitting device, comprising:
a semiconductor light-emitting element emitting ultraviolet light or violet light; and
a light-emitting unit, which is excited by the light from the semiconductor light-emitting element to emit white light, including three or more kinds of visible light-emitting phosphors,
wherein emission spectrum of the light-emitting unit has peaks in a blue region of not less than 440 nm nor more than 460 nm, a green region of not less than 510 nm nor more than 530 nm, and a red region of not less than 620 nm nor more than 640 nm, and the three or more kinds of visible light-emitting phosphors are bound together with a binder in advance,
wherein both an average primary particle size before bonding and an average secondary particle size after bonding of the three or more kinds of visible light-emitting phosphors are 7 μm or more.