Diffuser for LED light sources

• US 8,415,695 B2
• Filed: 10/21/2008
• Issued: 04/09/2013
• Est. Priority Date: 10/24/2007
• Status: Expired due to Fees

• Current Assignee: Switch Bulb Company, Inc.
• Original Assignee: Switch Bulb Company, Inc.
• Inventors: Lenk, Carol
• Primary Examiner(s): Lee, Eugene
• Application Number:
  US12/739,944
• Publication Number:
  US 20110042700A1
• Time in Patent Office: 1,631 Days
• Field of Search: 257/98
• US Class Current: 257/98
• CPC Class Codes: F21V 17/04 the fastening being onto or by the light source
• CPC Class Codes: F21V 17/06 the fastening being onto or by the lampholder
• 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 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 5/00 Refractors for light sources characterised by cooling arrangements F21V29/504
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 5/0242 by means of dispersed particles
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

An LED light source, which includes at least one LED, a panel between the LED and the light emission surface of the light source, and a filler material inside the panel containing a material to diffuse the light from the at least one LED by Mie scattering.

Claims

1. An LED light source comprising:

at least one LED emitting a light, wherein the light has a dominant wavelength;

and

a filler material containing a particles to diffuse the light from the at least one LED by Mie scattering,

wherein the filler material is disposed between the at least one LED and a light emission surface of the light source, and

wherein the mean diameter of the particles is greater than the dominant wavelength of the light.

2. An LED light source as set forth in claim 1, wherein the filler material is a fluid.

3. An LED light source as set forth in claim 1, wherein the filler material is a gel.

4. An LED light source as set forth in claim 1, wherein the filler material is a plastic.

5. An LED light source as set forth in claim 1, wherein the filler material is thermally conductive.

6. An LED light source as set forth in claim 1, wherein the filler material is uniformly distributed in a space between the at least one LED and the light emission surface of the light source.

7. An LED light source as set forth in claim 1, wherein the particles are uniformly distributed in the filler material.

8. An LED light source as set forth in claim 1, wherein the filler material has a non-uniform distribution throughout the panel.

9. An LED light source as set forth in claim 1, wherein the Mie scatterers have a non-uniform distribution throughout the panel.

10. An LED light source as set forth in claim 1, wherein the at least one LED is a blue or ultraviolet LED without a phosphor, and the filler material panel contains at least one phosphor.

11. An LED light source as set forth in claim 1, wherein the filler material does not entirely fill a space between the at least one LED and the light emission surface of the light source.

12. An LED light source as set forth in claim 1, wherein the filler material is a hydrogel.

13. An LED light source comprising:

at least one LED emitting a light, wherein the light has a dominant wavelength;

and

a poly(acrylamide) hydrogel containing particles to scatter the light from the at least one LED by Mie scattering,

wherein the poly(acrylamide) hydrogel is disposed between the at least one LED and a light emission surface of the light source, and

wherein the mean diameter of the particles is greater than the dominant wavelength of the light.

14. An LED light source as set forth in claim 13, wherein the particles have been lightly coated with inorganic particles.

15. An LED light source as set forth in claim 14, wherein the inorganic particles are calcium carbonate.

16. An LED light source comprising:

at least one LED;

and

a hydrocarbon-based oil containing particles to scatter the light from the at least one LED by Mie scattering,

wherein the hydrocarbon-based oil is disposed between the at least one LED and a light emission surface of the light source, and

wherein the hydrocarbon-based oil further contains water and a small amount of a surfactant.

17. An LED light source as set forth in claim 16, wherein the hydrocarbon-based oil is composed of components that are individually each transparent to light.