Light-emitting device and illuminating apparatus

• US 7,503,676 B2
• Filed: 07/26/2007
• Issued: 03/17/2009
• Est. Priority Date: 07/26/2006
• Status: Expired due to Fees

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Sakumoto, Daisuke
• Primary Examiner(s): Lee; Y My Quach
• Application Number:
  US11/828,775
• Publication Number:
  US 20080049430A1
• Time in Patent Office: 600 Days
• Field of Search: 362/84, 362/231, 362/243, 362/293, 362/310, 362/311, 362/800, 313/501, 313/502, 313/512, 257/98, 257/100
• US Class Current: 362/293
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/08 containing inorganic luminescent materials
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A light-emitting device has a base, a light-emitting chip and a light emitter. The light-emitting chip is made of semiconductor material, and is mounted on the base. The light-emitting chip generates the primary light. The light emitter includes fluorescent material being excited by the primary light to emit a secondary light. The light emitter has a first surface with uneven surface texture.

Claims

1. A light-emitting device comprising:

a base;

a light-emitting chip made of semiconductor material, mounted on the base, and configured to generate a primary light; and

a light emitter having a first surface facing inward towards the light-emitting chip, and including a plurality of particles of fluorescent material configured to be excited by the primary light to emit a secondary light, wherein the first surface has a configuration outwardly bulged by shapes of inner-most particles of the plurality of particles of fluorescent material.

2. A light-emitting device according to claim 1, wherein the light emitter further has a second surface, the first surface is rougher than the second surface.

3. A light-emitting device according to claim 2, wherein the light emitter is apart from the light-emitting chip.

4. A light-emitting device according to claim 3, wherein the light emitter is made of resin containing the plurality of particles of fluorescent material.

5. A light-emitting device according to claim 4, wherein the resin is silicone with a specific gravity included within a range from 0.9 to 1.1.

6. A light-emitting device according to claim 5, wherein the plurality of particles of fluorescent material has a specific gravity included within a range from 3.8 to 5.1.

7. A light-emitting device according to claim 3, further comprising:

a light reflecting surface surrounding the light-emitting chip and configured to scatter the primary light reflected by the light emitter.

8. A light-emitting device according to claim 7, wherein the light reflecting surface is configured to scatter the secondary light.

9. A light-emitting device according to claim 3, wherein the light emitter has a dome shape.

10. A light-emitting device according to claim 1, wherein the fluorescent material is distributed to be shifted to the first surface side of the light emitter.

11. A light-emitting device according to claim 1, further comprising:

a transparent material layer encapsulating the light-emitting chip, and being apart from the first surface of the light emitter.

12. A light-emitting device according to claim 1, wherein the first surface of the light emitter is located in further inward than the inner-most particles of the plurality of particles of fluorescent material.

13. A light-emitting device according to claim 12, wherein the inner-most particles of the plurality of particles of fluorescent material emit at least a part of a wavelength range from 625 nm to 740 nm.

14. A light-emitting device according to claim 1,

wherein the light emitter further comprises:

a fluorescent material layer containing the plurality of particles of fluorescent material;

a first transparent resin layer located in an inner surface side of the light emitter and including the first surface, the first transparent resin layer not containing particles of the plurality of particles of fluorescent material; and

a second transparent resin layer located in an outer surface side of the light emitter such that the fluorescent material layer is in between the first transparent resin layer and the second transparent resin layer, the second transparent resin layer not containing particles of the plurality of particles of fluorescent material,

wherein a thickness of the first transparent resin layer is thinner than a thickness of the second transparent resin layer.

15. A light-emitting device according to claim 1, wherein the plurality of particles of fluorescent material of the light emitter is distributed to have a higher concentration of particles towards a first surface side of the light emitter than towards a second surface side of the light emitter.

16. An illuminating apparatus comprising:

a substrate with a conductive pattern;

a light-emitting chip made of semiconductor material, and connected electrically to the conductive pattern; and

a light emitter including a plurality of particles of fluorescent material, having a first surface facing inward towards the light-emitting chip, and covering the light-emitting chip, wherein the first surface has a configuration outwardly bulged by shapes of inner-most particles of the plurality of particles of fluorescent material.

17. An illuminating apparatus according to claim 16, further comprising:

a light reflector disposed in a location where light emitted outward from the light emitter reaches.

18. An illuminating apparatus according to claim 16, further comprising:

a lens covering the light emitter.

19. A light-emitting device comprising:

a light source configured to generate a primary light with a first wavelength; and

a wavelength-conversion means for converting the primary light with the first wavelength into a second wavelength different from the first wavelength, wherein the wavelength-conversion means includes a first surface facing inward towards the light source and a plurality of particles of fluorescent material, and wherein the first surface has a configuration outwardly bulged by shapes of inner-most particles of the plurality of particles of fluorescent material.

20. A light-emitting device according to claim 19, further comprising:

means for encapsulating the light source.

21. A light-emitting device according to claim 20, further comprising:

means for diffusing the primary light and emitting the primary light to the wavelength-conversion means.