LED package with converging optical element

• US 7,525,126 B2
• Filed: 05/02/2006
• Issued: 04/28/2009
• Est. Priority Date: 05/02/2006
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Leatherdale, Catherine A., Ouderkirk, Andrew J., Lu, Dong
• Primary Examiner(s): Fahmy, Wael
• Assistant Examiner(s): Yang, Minchul
• Application Number:
  US11/381,324
• Publication Number:
  US 20070257266A1
• Time in Patent Office: 1,092 Days
• Field of Search: 257/79, 257/98, 257/95, 257/99, 257/100, 257E33055-E33059
• 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 19/0071 adapted to illuminate a complete hemisphere or a plane extending 360 degrees around the source
• CPC Class Codes: G02B 27/0972 Prisms prisms per se G02B5/04
• 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 33/58 Optical field-shaping elements

Abstract

The present application discloses a light source comprising an LED die having an emitting surface and an optical element including a base, an apex smaller than the base, and a converging side extending between the base and the apex, wherein the base is optically coupled to and is no greater in size than the emitting surface, and wherein the optical element directs light emitted by the LED die to produce a side emitting pattern.

Claims

1. A light source, comprising:

an LED die having an LED die emitting surface; and

an optical element including a base, an apex smaller than the base, and a converging side extending between the base and the apex, wherein the base is optically coupled to and is no greater in size than the emitting surface and the optical element is mechanically decoupled from the LED die and a gap between the LED die emitting surface and the base has a thickness on the order of a wavelength of light of interest in air;

wherein the optical element directs light emitted by the LED die to produce a side emitting pattern.

2. The light source of claim 1, wherein the side emitting pattern includes a plurality of side lobes.

3. The light source of claim 1, wherein the side emitting pattern is torroidal.

4. The light source of claim 1, wherein the side emitting pattern is asymmetric.

5. The light source of claim 1, wherein the apex resides over the emitting surface.

6. The light source of claim 1, wherein the apex is centered over the base.

7. The light source of claim 1, wherein the apex is blunted.

8. The light source of claim 1, further comprising an optically conducting layer disposed between the optical element and the emitting surface.

9. The light source of claim 8, wherein the thickness of the optically conducting layer is less than 50 nm.

10. The light source of claim 1, wherein the side emitting pattern has an intensity distribution having a maximum at a polar angle of at least 30 degrees.

11. The light source of claim 1, wherein the side emitting pattern has an intensity distribution centered at a polar angle of at least 30 degrees.

12. The light source of claim 1, wherein the base and the emitting surface are substantially matched in size.

13. The light source of claim 1, wherein the base is smaller than the emitting surface.

14. The light source of claim 1, wherein the optical element has an index of refraction, N_o≧

1.75.

15. The light source of claim 1, wherein the optical element consists of inorganic material.

16. The light source of claim 1, wherein the LED die is one of a plurality of LED dies arranged in an array.

17. The light source of claim 1, wherein the base is rectangular and wherein the optical element includes four sides.

18. A direct-lit backlight comprising the light source of claim 1.