High brightness LED package with multiple optical elements

• US 20060092532A1
• Filed: 10/29/2004
• Published: 05/04/2006
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Ouderkirk, Andrew J., Leatherdale, Catherine A.
• Granted Patent: US 7,330,319 B2
• Time in Patent Office: Days
• US Class Current: 359/819
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A light source includes an LED die with an emitting surface and a plurality of optical elements having input surfaces in optical contact with distinct portions of the emitting surface. The optical elements can comprise tapers or concentrators that have reflective side surface(s) and output surfaces larger than the respective input surfaces. The optical elements can couple both light and heat out of the emitting surface of the LED die.

Claims

1. A light source, comprising:

an LED die having an emitting surface; and

a plurality of optical elements, each such optical element having an input surface;

wherein the optical elements are sized such that the input surfaces are spaced apart from each other and are in optical contact with different portions of the emitting surface.

2. The light source of claim 1, wherein the optical elements collimate light incident at their input surfaces.

3. The light source of claim 1, wherein the optical elements are defined by one or more grooves in a unitary piece of material.

4. The light source of claim 1, wherein the optical elements are bonded to the emitting surface at their respective input surfaces.

5. The light source of claim 1, wherein each optical element also has an output surface.

6. The light source of claim 5, wherein, for at least one optical element, the input surface is smaller than the output surface.

7. The light source of claim 5, wherein each optical element includes at least one reflective side surface between the respective input surface and output surface.

8. The light source of claim 5, wherein the output surface of at least one optical element is curved.

9. The light source of claim 1, wherein the optical elements comprise a material having a refractive index of at least 1.8.

10. The light source of claim 1, wherein the optical elements comprise a material having a thermal conductivity of at least 0.2 W/cm/K.

11. The light source of claim 1, wherein the optical elements comprise a material selected from the group of sapphire, diamond, and silicon carbide.

12. The light source of claim 1, wherein the optical elements define gaps therebetween.

13. The light source of claim 12, wherein at least one electrical connection for the LED die passes through at least one of the gaps.

14. The light source of claim 12, further comprising a fluid disposed in the gaps.

15. The light source of claim 1, wherein the plurality of optical elements comprise a 2×

2 array of optical elements.

16. The light source of claim 1, wherein the plurality of optical elements comprise a 3×

3 array of optical elements.