COLOR CONVERSION CAVITIES FOR LED-BASED ILLUMINATION MODULES

• US 20120250320A1
• Filed: 03/27/2012
• Published: 10/04/2012
• Est. Priority Date: 03/31/2011
• Status: Abandoned Application

• Current Assignee: Xicato, Inc.
• Original Assignee: Xicato, Inc.
• Inventors: Harbers, Gerard, Eng, Gregory W., Tseng, Peter K., Yriberri, John S.
• Application Number:
  US13/431,796
• Publication Number:
  US 20120250320A1
• Time in Patent Office: Days
• US Class Current: 362/247
• CPC Class Codes: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 13/08 the elements being filters or photoluminescent elements and reflectors
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/0025 Combination of two or more reflectors for a single light source array of reflectors for a cluster of light sources F21V7/0083
• CPC Class Codes: F21V 7/0083 Array of reflectors for a cluster of light sources, e.g. arrangement of multiple light sources in one plane combination of two or more reflectors F21V7/0025
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/16 square or rectangular, e.g. for light panels
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2113/17 forming a single encapsulated light source
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An illumination module includes a plurality of Light Emitting Diodes (LEDs). Multiple color conversion cavities are present, each with sidewalls coated with wavelength converting materials. One or more LEDs are located within each color conversion cavity. A transmissive layer may be deposited over the color conversion cavities and may include additional wavelength converting material. The wavelength converting materials may be selected to produce an output light with target color point. Additionally, a secondary light mixing cavity may be present over the multiple color conversion cavities.

Claims

1. An LED based illumination device, comprising:

a sidewall with a first surface area comprising a portion of an interior surface area of a first color conversion cavity and a second surface area comprising a portion of an interior surface area of a second color conversion cavity, wherein the first surface area is coated with a first wavelength converting material, and wherein the second surface area is coated with a second wavelength converting material;

a first LED, wherein light emitted from the first LED directly enters the first color conversion cavity and does not directly enter the second color conversion cavity; and

a second LED, wherein light emitted from the second LED directly enters the second color conversion cavity and does not directly enter the first color conversion cavity.

2. The LED based illumination device of claim 1, further comprising:

a transmissive layer mounted above the first color conversion cavity and the second color conversion cavity, wherein a first portion of the transmissive layer covers the first color conversion cavity, and wherein a second portion of the transmissive layer covers the second color conversion cavity.

3. The LED based illumination device of claim 2, wherein the transmissive layer is coated with a third wavelength converting material.

4. The LED based illumination device of claim 2, wherein the transmissive layer is coupled to the sidewall.

5. The LED based illumination device of claim 1, wherein the first and the second wavelength converting material are the same material.

6. The LED based illumination device of claim 3, wherein any of the first wavelength converting material, the second wavelength converting material, and the third wavelength converting material is selected such that a color point of an output light emitted from the LED based illumination device matches a target color point.

7. The LED based illumination device of claim 1, wherein a current supplied to the first LED is selected such that a color point of an output light emitted from the LED based illumination device matches a target color point.

8. The LED based illumination device of claim 1, further comprising:

a secondary light mixing cavity disposed above the first color conversion cavity and the second color conversion cavity, the secondary light mixing cavity, comprising;

a reflective sidewall, and

an output window of the LED based illumination device.

9. The LED based illumination device of claim 1, wherein a peak emission wavelength of the first LED differs from a peak emission wavelength of the second LED.

10. An LED based illumination device, comprising:

a plurality of LEDs;

a translucent, non-planar shaped window disposed above and spaced apart from the plurality of LEDs, the translucent, non-planar shaped window including a first wavelength converting material that color converts an amount of light emitted from the plurality of LEDs, wherein a reflector attached to the LED based illumination device has an interior volume that envelops the translucent, non-planar shaped window; and

a first color conversion cavity including a reflective sidewall that extends in a direction from a plane in which at least one LED of the plurality of LEDs is disposed toward a transmissive layer disposed between the plurality of LEDs and the translucent, non-planar shaped window, wherein a portion of the transmissive layer is coated with a second wavelength converting material.

11. The LED based illumination device of claim 10, wherein the reflective sidewall includes a third wavelength converting material.

12. The LED based illumination device of claim 10, further comprising:

a mounting board upon which the plurality of LEDs are attached; and

a base reflector disposed above the mounting board.

13. The LED based illumination device of claim 10, wherein the translucent, non-planar shaped window is a dome shape.

14. The LED based illumination device of claim 10, wherein the translucent, non-planar shaped window includes a reflective portion disposed at an apex of the translucent, non-planar shaped window.

15. The LED based illumination device of claim 10, wherein the plurality of LEDs are mounted in the plane and wherein a surface of the translucent, non-planar shaped window is oriented at an oblique angle with respect to the plane.

16. The LED based illumination device of claim 10, wherein the reflective sidewall surrounds the at least one LED of the plurality of LEDs and is oriented at an oblique angle with respect to the plane in which the at least one LED is disposed.

17. The LED based illumination device of claim 10, further comprising:

a second color conversion cavity disposed between a second LED of the plurality of LEDs and the translucent, non-planar shaped window, wherein a portion of an interior surface area of the second color conversion cavity is coated with a third wavelength converting material, wherein light emitted from a first LED of the plurality of LEDs directly enters the first color conversion cavity and does not directly enter the second color conversion cavity, and wherein light emitted from the second LED of the plurality of LEDs directly enters the second color conversion cavity and does not directly enter the first color conversion cavity.

18. An apparatus, comprising:

a light emitting diode (LED) of a plurality of LEDs disposed in a first plane, the LED having a central axis extending perpendicular to a die area of the LED; and

a color conversion cavity including a reflective sidewall that surrounds the LED, wherein the reflective sidewall is oriented at an oblique angle with respect to the first plane and extends from the first plane to a second plane that lies a first distance above the first plane, and a transmissive layer disposed in the second plane and attached to the reflective sidewall, wherein a portion of the transmissive layer is coated with a first wavelength converting material, and wherein the first distance is less than half a distance measured in the second plane from a point of attachment of the transmissive layer to the reflective sidewall and the central axis of the LED.

19. The apparatus of claim 18, further comprising:

a convex spherical reflector attached to the transmissive layer and disposed above the LED between the transmissive layer and the LED.

20. The apparatus of claim 18, further comprising:

a window disposed above and spaced apart from the transmissive layer, wherein a portion of the window is coated with a second wavelength converting material.

21. The apparatus of claim 18, wherein the reflective sidewall is diffuse reflective and at least a portion of the reflective sidewall is coated with the first wavelength converting material.

22. The apparatus of claim 18, wherein a space between the LED and the reflective sidewall is filled with a solid, transparent medium.

23. The apparatus of claim 22, wherein the first wavelength converting material is embedded in the solid, transparent medium.