LIGHT-EMITTING DEVICE, DISPLAY APPARATUS, ILLUMINATION APPARATUS, AND ELECTRICITY-GENERATING APPARATUS

• US 20150003040A1
• Filed: 09/11/2012
• Published: 01/01/2015
• Est. Priority Date: 09/16/2011
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Bessho, Hisanori, Koden, Mitsuhiro, Iwata, Akiko, Fujita, Yoshimasa, Kobayashi, Yuhki
• Granted Patent: US 9,091,415 B2
• Time in Patent Office: Days
• US Class Current: 362/84
• CPC Class Codes: F21V 13/02 Combinations of only two kinds of elements
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 9/40 with provision for controlling spectral properties, e.g. colour, or intensity
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133617 Illumination with ultraviolet light; Luminescent elements or materials associated to the cell
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/854 comprising scattering means
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/877 comprising scattering means
• CPC Class Codes: H10K 59/878 comprising reflective means

Abstract

A light-emitting device includes an excitation light source that emits excitation light; a first substrate which is disposed so as to face the excitation light source and on which a fluorescent layer and a first low-refractive-index layer are formed, the fluorescent layer being excited by the excitation light to emit fluorescence; and a barrier that surrounds side surfaces of the fluorescent layer, the side surfaces extending in a stacking direction of the excitation light source and the first substrate. At least a portion of the barrier that faces the fluorescent layer has a light-scattering property. The first low-refractive-index layer is located between the fluorescent layer and the first substrate. The first low-refractive-index layer has a refractive index lower than that of the first substrate.

Claims

1. A light-emitting device comprising:

an excitation light source that emits excitation light;

a first substrate which is disposed so as to face the excitation light source and on which a fluorescent layer and a first low-refractive-index layer are formed, the fluorescent layer being excited by the excitation light to emit fluorescence; and

a barrier that surrounds side surfaces of the fluorescent layer, the side surfaces extending in a stacking direction of the excitation light source and the first substrate,

wherein at least a portion of the barrier that faces the fluorescent layer has a light-scattering property,

the first low-refractive-index layer is located between the fluorescent layer and the first substrate, and

the first low-refractive-index layer has a refractive index lower than that of the first substrate.

2. The light-emitting device according to claim 1, further comprising a second substrate disposed on an incident surface side of the fluorescent layer upon which the excitation light is incident.

3. The light-emitting device according to claim 1, further comprising a second low-refractive-index layer located on an incident surface side of the fluorescent layer upon which the excitation light is incident.

4. The light-emitting device according to claim 1, further comprising a wavelength-selective transmission/reflection layer configured to transmit at least light with a peak wavelength of the excitation light and reflect at least light with an emission peak wavelength of the fluorescent layer, the wavelength-selective transmission/reflection layer being located on an incident surface side of the fluorescent layer upon which the excitation light is incident.

5. The light-emitting device according to claim 4, wherein the second low-refractive-index layer is located between the fluorescent layer and the wavelength-selective transmission/reflection layer or between the wavelength-selective transmission/reflection layer and the excitation light source.

6. The light-emitting device according to claim 1, wherein the fluorescent layer is constituted by a plurality of separated fluorescent layers each located in a predetermined region, and the first low-refractive-index layer is formed so as to extend between the plurality of separated fluorescent layers and the first substrate.

7. The light-emitting device according to claim 6, further comprising a light-absorbing layer disposed between two adjacent separated fluorescent layers among the plurality of separated fluorescent layers.

8. The light-emitting device according to claim 7, wherein the light-absorbing layer is located on at least one of an upper surface and a lower surface of the barrier.

9. The light-emitting device according to claim 7, wherein the light-absorbing layer is located between the first low-refractive-index layer and the first substrate.

11. The light-emitting device according to claim 1, wherein the first low-refractive-index layer has such a refractive index that an outgoing angle of incident light that enters the first substrate from the first low-refractive-index layer is smaller than a critical angle of at least incident light that can be output from the first substrate toward the outside.

12. The light-emitting device according to claim 1, wherein the first low-refractive-index layer is composed of a gas.

13. The light-emitting device according to claim 12, further comprising a gas barrier film configured to block the gas, the gas barrier film being disposed on an incident surface side of the fluorescent layer upon which the excitation light is incident.

14. The light-emitting device according to claim 1, wherein at least a portion of the barrier that faces the fluorescent layer is formed of a material containing a resin and light-scattering particles.

16. The light-emitting device according to claim 1, wherein at least a portion of the barrier that faces the fluorescent layer has irregularities.

17. A display apparatus comprising the light-emitting device according to claim 1.

18. The display apparatus according to claim 17,

wherein the excitation light source emits excitation light in an ultraviolet region, and

the fluorescent layer includes a red fluorescent layer that emits red light through irradiation with the excitation light and constitutes a red pixel, a green fluorescent layer that emits green light through irradiation with the excitation light and constitutes a green pixel, and a blue fluorescent layer that emits blue light through irradiation with the excitation light and constitutes a blue pixel.

19. The display apparatus according to claim 17,

wherein the excitation light source emits blue excitation light, and

the fluorescent layer includes a red fluorescent layer that emits red light through irradiation with the excitation light and constitutes a red pixel, a green fluorescent layer that emits green light through irradiation with the excitation light and constitutes a green pixel, and a scattering layer that scatters the excitation light and constitutes a blue pixel.

21. The display apparatus according to claim 17, wherein the fluorescence is output to the outside from the first substrate.

22. The display apparatus according to claim 17, wherein the excitation light source is a light-emitting diode, an organic electroluminescence element, or an inorganic electroluminescence element.

25. The display apparatus according to claim 17, further comprising a polarizing plate having an extinction ratio of 10000 or more at a wavelength of 435 nm or more and 480 nm or less, the polarizing plate being disposed between the excitation light source and the first substrate.

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