Light emitting device, display apparatus, and illuminating apparatus

• US 9,117,977 B2
• Filed: 12/20/2011
• Issued: 08/25/2015
• Est. Priority Date: 12/27/2010
• 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, Ishida, Takeshi, Fujita, Yoshimasa, Kobayashi, Yuhki
• Primary Examiner(s): Lee, Jae
• Assistant Examiner(s): Alam, Mohammed R
• Application Number:
  US13/997,650
• Publication Number:
  US 20130299816A1
• Time in Patent Office: 1,344 Days
• Field of Search: 313500-512
• US Class Current: 1/1
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• 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: H01L 33/60 Reflective elements
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses
• CPC Class Codes: H10K 50/865 comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/878 comprising reflective means
• CPC Class Codes: H10K 59/879 comprising refractive means, e.g. lenses
• CPC Class Codes: H10K 59/8792 comprising light absorbing layers, e.g. black layers

Abstract

A light emitting device includes an excitation light source element that emits excitation light; a substrate that faces the excitation light source element; a fluorescent layer located on the substrate, the fluorescent layer being excited by the excitation light to emit fluorescence; an optical reflection body disposed on a side surface of the fluorescent layer, the side surface extending in a direction parallel to a stacking direction of the substrate and the fluorescent layer; and a low-refractive-index material layer disposed between the fluorescent layer and the substrate, the low-refractive-index material layer having a refractive index lower than that of the substrate.

Claims

1. A light emitting device comprising:

an excitation light source element that emits excitation light;

a substrate that faces the excitation light source element;

a fluorescent layer located on the substrate, the fluorescent layer being excited by the excitation light to emit fluorescence;

an optical reflection body disposed on a side surface of the fluorescent layer, the side surface extending in a direction parallel to a stacking direction of the substrate and the fluorescent layer;

a low-refractive-index material layer disposed between the fluorescent layer and the substrate, the low-refractive-index material layer having a refractive index lower than that of the substrate; and

a wavelength-selective layer that transmits at least excitation light in a peak wavelength region of a wavelength range of the excitation light and reflects at least fluorescence in a peak wavelength region of a wavelength range of the fluorescence emitted from the fluorescent layer,

wherein the fluorescent layer has an incidence surface from which the excitation light enters, the incidence surface facing the excitation light source element, and

the wavelength-selective layer is disposed on the incidence surface.

2. The light emitting device according to claim 1, wherein the fluorescent layer is separated into a plurality of regions, and the low-refractive-index material layer is disposed between the substrate and each of the separated regions of the fluorescent layer.

3. The light emitting device according to claim 2, wherein a light-absorbing layer is disposed between adjacent regions among the separated regions of the fluorescent layer.

4. The light emitting device according to claim 3, wherein the light-absorbing layer is disposed between the low-refractive-index material layer and the substrate.

5. The light emitting device according to claim 3, wherein a surface of the light-absorbing layer, the surface facing the fluorescent layer, is covered with the low-refractive-index material layer.

6. The light emitting device according to claim 1, wherein the low-refractive-index material layer has such a refractive index that a critical angle of incident light that enters the low-refractive-index material layer from the fluorescent layer is smaller than a critical angle of outgoing light output from the second substrate toward an outside.

7. The light emitting device according to claim 1, wherein the substrate is curved so that at least edges of the substrate are located closer to the excitation light source element.

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

9. The display apparatus according to claim 8,

wherein the excitation light source element emits excitation light in an ultraviolet wavelength range, and

the fluorescent layer includes at least a red fluorescent layer constituting a red pixel that emits red light by using the excitation light, a green fluorescent layer constituting a green pixel that emits green light by using the excitation light, and a blue fluorescent layer constituting a blue pixel that emits blue light by using the excitation light.

10. The display apparatus according to claim 8,

wherein the excitation light source element emits blue excitation light,

the fluorescent layer includes at least a red fluorescent layer constituting a red pixel that emits red light by using the excitation light and a green fluorescent layer constituting a green pixel that emits green light by using the excitation light, and

the display apparatus includes a scattering layer constituting a blue pixel that scatters the excitation light.

11. The display apparatus according to claim 8, further comprising an active-matrix drive element that drives the excitation light source element.

12. The display apparatus according to claim 11, wherein the fluorescence is output from the substrate toward an outside.

13. The display apparatus according to claim 8, wherein the excitation light source element is constituted by a light emitting diode, an organic electroluminescence element, or an inorganic electroluminescence element.

14. The display apparatus according to claim 8, further comprising:

a liquid crystal element that is disposed between the excitation light source element and the substrate and can control a transmittance of the excitation light,

wherein the excitation light source element serves as a planar light source.

15. An illuminating apparatus comprising the light emitting device according to claim 1.

16. The light emitting device according to claim 1, wherein the low-refractive-index material layer has a refractive index equal to or lower than 1.5.

17. The light emitting device according to claim 16, wherein the low-refractive-index material layer has a refractive index of 1.35 to 1.4.

18. The light emitting device according to claim 16, wherein the low-refractive-index material layer comprises a fluorocarbon resin.

19. A light emitting device comprising:

an excitation light source element that emits excitation light;

a substrate that faces the excitation light source element;

a fluorescent layer located on the substrate, the fluorescent layer being excited by the excitation light to emit fluorescence;

an optical reflection body disposed on a side surface of the fluorescent layer, the side surface extending in a direction parallel to a stacking direction of the substrate and the fluorescent layer; and

a low-refractive-index material layer disposed between the fluorescent layer and the substrate, the low-refractive-index material layer having a refractive index lower than that of the substrate,

wherein the fluorescent layer is separated into a plurality of regions, and the low-refractive-index material layer is disposed between the substrate and each of the separated regions of the fluorescent layer,

a light-absorbing layer is disposed between adjacent regions among the separated regions of the fluorescent layer, and

wherein the light-absorbing layer is disposed between the low-refractive-index material layer and the substrate.

20. A light emitting device comprising:

an excitation light source element that emits excitation light;

a substrate that faces the excitation light source element;

a fluorescent layer located on the substrate, the fluorescent layer being excited by the excitation light to emit fluorescence;

an optical reflection body disposed on a side surface of the fluorescent layer, the side surface extending in a direction parallel to a stacking direction of the substrate and the fluorescent layer; and

a low-refractive-index material layer disposed between the fluorescent layer and the substrate, the low-refractive-index material layer having a refractive index lower than that of the substrate,

wherein the fluorescent layer is separated into a plurality of regions, and the low-refractive-index material layer is disposed between the substrate and each of the separated regions of the fluorescent layer,

a light-absorbing layer is disposed between adjacent regions among the separated regions of the fluorescent layer, and

wherein a surface of the light-absorbing layer, the surface facing the fluorescent layer, is covered with the low-refractive-index material layer.