Devices for creating brightness profiles

• US 6,974,229 B2
• Filed: 05/21/2003
• Issued: 12/13/2005
• Est. Priority Date: 05/21/2003
• Status: Expired due to Term

• Current Assignee: Lumileds Lighting US LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds Lighting US LLC (Apollo Global Management, Inc.)
• Inventors: West, Robert S., Kuppens, Simon J. M., Martynov, Yourii, Pfeffer, Nicola, Konijn, Huub
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): PAYNE, SHARON E
• Application Number:
  US10/442,346
• Publication Number:
  US 20040233665A1
• Time in Patent Office: 937 Days
• Field of Search: 362/227, 362/31, 362/555, 362/558, 362/560, 362/561, 362/511, 362/545, 362/228, 362/231, 362/240, 362/241, 362/243, 362/296, 362/341, 362/800, 362/330, 362/343
• US Class Current: 362/227
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A mixing chamber includes a first surface and a second surface opposite the first surface. At least two light emitting diodes are disposed along the first surface. At least a portion of the first surface is reflective, and the second surface includes a reflective region and a plurality of openings formed in the reflective region. In some embodiments, the first surface and the second surface are separated by at least one side surface. Light emitted from the light emitting diodes is reflected off the first surface, reflective region of the second surface, and side surfaces of the mixing chamber until it is emitted from the openings of the second surface.

Claims

1. A structure comprising:

a mixing chamber, the mixing chamber comprising;

a first surface, wherein at least a portion of the first surface is reflective; and

a second surface opposite the first surface, the second surface comprising;

a reflective region; and

a plurality of openings in the reflective region;

a plurality of light emitting diodes disposed along the first surface; and

a lens disposed over at least one of the plurality of light emitting diodes, the lens comprising;

a bottom surface;

a reflecting surface; and

a refracting surface obliquely angled with respect to a central axis of the lens,

wherein light entering the lens through the bottom surface and directly incident on the reflecting surface is reflected from the reflecting surface to the refracting surface and refracted by the refracting surface to exit the lens in a substantially perpendicular to the central axis of the lens.

2. The structure of claim 1 further comprising one or more side surfaces separating the first surface from the second surface.

3. The structure of claim 2 wherein at least a portion of at least one of the one or more side surfaces is reflective.

4. The structure of claim 1 wherein the reflective portion of the first surface is at least 90% reflective of light emitted by the plurality of light emitting diodes.

5. The structure of claim 1 wherein the reflective portion of the first surface is at least 98% reflective of light emitted by the plurality of light emitting diodes.

6. The structure of claim 1 wherein the reflective region of the second surface is at least 90% reflective of light emitted by the plurality of light emitting diodes.

7. The structure of claim 1 wherein the reflective region of the second surface is at least 98% reflective of light emitted by the plurality of light emitting diodes.

8. The structure of claim 1 wherein:

the plurality of light emitting diodes are disposed in a row; and

the openings comprise slits parallel to the row of light emitting diodes.

9. The structure of claim 8 wherein an area of the second surface directly over the plurality of light emitting diodes is part of the reflective region.

10. The structure of claim 1 wherein the mixing chamber is filled with air.

11. The structure of claim 1 further comprising a plurality of openings formed in the reflective portion of the first surface.

12. The structure of claim 1 wherein the plurality of light emitting diodes includes at least four light emitting diodes each emitting light at a different wavelength.

13. The structure of claim 1 wherein the plurality of light emitting diodes includes at least one phosphor-converted light emitting diode.

14. The structure of claim 1 wherein the second surface comprises a transparent material, and the reflective region comprises a reflective material formed on the transparent material.

15. The structure of claim 1 wherein the second surface comprises a diffuser, and the reflective region comprises a reflective material formed on the diffuser.

16. A structure comprising:

a mixing chamber, the mixing chamber comprising;

a first surface, wherein at least a portion of the first surface is reflective; and

a second surface opposite the first surface, the second surface comprising

a reflective region; and

a plurality of openings in the reflective region;

a plurality of light emitting diodes disposed along the first surface;

a first diffuser overlying the second surface;

a second mixing chamber overlying the first diffuser; and

a second diffuser overlying the second mixing chamber.

17. The structure of claim 16 further comprising a liquid crystal layer overlying the first diffuser.

18. The structure of claim 16 wherein the plurality of light emitting diodes include red, blue, and green light emitting diodes.