Light-emitting apparatus with shaped wavelength converter

• US 8,410,500 B2
• Filed: 12/14/2007
• Issued: 04/02/2013
• Est. Priority Date: 12/21/2006
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Sormani, Joseph Ludovicus Antonius Maria, Lenderink, Egbert, Epmeier, Matthias Daniel, Weijers, Aldegonda Lucia
• Primary Examiner(s): Smoot, Stephen W
• Assistant Examiner(s): Booker, Vicki B
• Application Number:
  US12/519,439
• Publication Number:
  US 20100019265A1
• Time in Patent Office: 1,936 Days
• Field of Search: 257/98, 257/E33.067
• US Class Current: 257/98
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 2207/113 Fluorescence
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

Proposed is a light-emitting apparatus 200,300,400, comprising a semiconductor light emitting device 220,320,420 and a transparent ceramic body 230,330,430 comprising a wavelength converting material positioned in light receiving relationship to the semiconductor device. The light-emitting apparatus is characterized in that the side surfaces 233,333,433 of the ceramic body 230,330,430 are at an oblique angle 234,334,434 relative its bottom surface 231,331,431. This is especially advantageous to unlock the wave-guide modes inside the body 230,330,430. Consequently the total flux emitted from the light-emitting apparatus 200,300,400 can be enhanced considerably. Alternatively, the brightness of the top surface 232,332,432 of the ceramic body 230,330,430 can be enhanced considerably.

Claims

1. A light-emitting apparatus comprising:

a semiconductor light emitting device comprising a light-emitting layer disposed between an n-type region and a p-type region,

a transparent ceramic body comprising a wavelength converting material positioned in light receiving relationship to the semiconductor light-emitting device,

the ceramic body further having a bottom surface facing towards the semiconductor light-emitting device, wherein the ceramic body has at least one side surface at an oblique angle with respect to the bottom surface,

wherein at least one surface of the ceramic body has a reflective coating, and

wherein an intermediate layer having a lower index of refraction than the ceramic body is disposed between the body and the reflective coating.

2. A light-emitting apparatus according to claim 1, wherein the oblique angle is larger than 95°

or smaller than 85°

.

3. A light-emitting apparatus according to claim 2, wherein the oblique angle is larger than 100°

or smaller than 80°

.

4. A light-emitting apparatus according to claim 1, wherein the at least one surface of the ceramic body is at least one oblique side surface of the ceramic body.

5. A light-emitting apparatus according to claim 1, wherein the ceramic body has a top surface provided with a micro-corrugation.

6. A light-emitting apparatus according to claim 1, wherein the ceramic body has a top surface provided to include an optical function.

7. A light-emitting apparatus according to claim 1, wherein the at least one surface of the ceramic body is a top surface of the ceramic body.

8. A light-emitting apparatus according to claim 1, wherein an other intermediate layer having a lower index of refraction than the ceramic body is accommodated between the bottom surface and the semiconductor light-emitting device.