High-power white LEDs

• US 9,105,816 B2
• Filed: 02/04/2014
• Issued: 08/11/2015
• Est. Priority Date: 11/17/2006
• Status: Active Grant

• Current Assignee: Rensselaer Polytechnic Institute
• Original Assignee: Rensselaer Polytechnic Institute
• Inventors: Narendran, Nadarajah, Gu, Yimin
• Primary Examiner(s): Petkovsek, Daniel
• Application Number:
  US14/172,308
• Publication Number:
  US 20140151736A1
• Time in Patent Office: 553 Days
• Field of Search: None
• US Class Current: 1/1
• 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 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/483 Containers
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• 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 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A light emitting apparatus has a first radiation source without a dome, a substantially transparent and light transmissive optic device devoid of scattering particles and phosphor, a lens, a down conversion material containing phosphor that is disposed on the planar top surface of the optic device between the lens and the radiation source, and a heat sink, upon which the radiation source is mounted, having a recess formed therein in which the radiation source, the optic device and the down conversion material are positioned, wherein an air space is defined between a boundary of the recess and the optic device.

Claims

1. A light emitting apparatus comprising:

a first radiation source without a dome;

a substantially transparent and light transmissive optic device devoid of scattering particles and phosphor, and comprising a planar top surface distal the first radiation source, a bottom surface proximal the first radiation source, and a transparent sidewall extending between the top surface and the bottom surface;

a lens;

a down conversion material comprising a flat layer including phosphor that is disposed on the planar top surface of the optic device between the lens and the radiation source; and

a heat sink, upon which the radiation source is mounted, having a recess formed therein in which the radiation source, the optic device and the down conversion material are positioned, wherein an air space is defined between a boundary of the recess and the optic device.

2. The light emitting apparatus of claim 1, further comprising a second radiation source having a dimension smaller than that of the first radiation source.

3. The light emitting apparatus of claim 1, further comprising a sealant between the optic device and the first radiation source.

4. The light emitting apparatus of claim 3, wherein the sealant has a refractive index of 1.5-2.3.

5. The light emitting apparatus of claim 1, wherein the optic device has a refractive index of 1.4-1.7.

6. The light emitting apparatus of claim 1, wherein the bottom surface has a width smaller than that of the top surface.

7. The light emitting apparatus of claim 1, wherein the transparent sidewall comprises a straight portion, a curved portion, or both thereof.