Lighting module with diffractive optical element

• US 8,465,172 B2
• Filed: 12/17/2009
• Issued: 06/18/2013
• Est. Priority Date: 12/17/2009
• Status: Active Grant

• Current Assignee: Excelitas Technologies Corporation (Excelitas Technologies Holdings LLC)
• Original Assignee: Phoseon Technology, Inc.
• Inventors: Marson, Jonathan L.
• Primary Examiner(s): Ton, Anabel
• Application Number:
  US12/641,161
• Publication Number:
  US 20110149565A1
• Time in Patent Office: 1,279 Days
• Field of Search: 362/800, 362/235, 362/249.1, 362/249.02, 362/249.11
• US Class Current: 362/235
• CPC Class Codes: G02B 19/0009 having refractive surfaces only
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02B 19/0095 for use with ultraviolet radiation

Abstract

A lighting module having an array of light-emitting elements on a substrate, at least one diffractive optical element arranged to receive light from the light-emitting elements and partially collimate the light. A method of packaging a lighting module including mounting at least one array of light-emitting elements on a substrate in a package, and enclosing the package with a window, the window has a diffractive optical element on a surface of the window closest to the array, the diffractive optical element arranged to partially collimate the light. A lighting module having an array of light-emitting elements on a substrate, at least one diffractive optical element arranged to receive light from the light-emitting elements and scatter the light into a random emission pattern to produce a uniform irradiance at a target surface.

Claims

1. A lighting module, comprising:

an array of light-emitting elements on a substrate;

a package containing the array of light-emitting elements and the substrate, the package enclosed with a window, wherein the window has two surfaces;

an array of diffractive optical elements mounted to one of the surfaces of the window such that a gap exists between the array of diffractive optical elements and the array of light-emitting elements, each diffractive optical element corresponding to a light-emitting element, the diffractive optical elements arranged to receive light from the light-emitting elements and so as to only partially collimate the light;

a lens element arranged adjacent to each light-emitting element to capture the light from the element; and

a target surface arranged at a distance from the lighting module to receive a uniform distribution of the partially collimated light.

2. The lighting module of claim 1, wherein the uniform distribution of the partially collimated light comprises a distribution having less than 30% divergence over the target surface.

3. The lighting module of claim 1, wherein a second diffractive optical element is arranged to scatter light into a random emission pattern to produce a uniform irradiance at a target work surface.

4. The lighting module of claim 1, wherein each of the diffractive optical elements comprises a holographic optical element.

5. The lighting module of claim 1, wherein each of the diffractive optical elements has a focal point in a first axis.

6. The lighting module of claim 3, wherein the second diffractive optical element has a focal point in a first axis.

7. The lighting module of claim 5, wherein each of the diffractive optical elements partially collimates the light in a second axis.

8. The lighting module of claim 1, wherein the gap exists between the lens element and the window.

9. The lighting module of claim 1, wherein the gap is filled with one of either air or a gel material.

10. The lighting module of claim 9, wherein the gel material comprises a material that is index matched to at least one of the window or the light-emitting elements.

11. A method of packaging a lighting module, comprising:

mounting at least one array of light-emitting elements on a substrate in a package; and

enclosing the package with a window, the window having two surfaces, the window having an array of diffractive optical elements mounted to the surface closest to the light-emitting element array such that a gap exists between the array of diffractive optical elements and the array of light-emitting elements, each diffractive optical element corresponding to a light-emitting element, the array of diffractive optical elements arranged at a distance to only partially collimate light at a target surface arranged at a distance from the lighting module so as to receive a uniform distribution of the partially collimated light.

12. The method of claim 11, wherein the diffractive optical elements are holographic optical elements.

13. The method of claim 11, wherein the window has pre-existing diffractive optical elements on the surface.

14. The method of claim 11, further comprising:

dispensing a gel over the array of light-emitting elements; and

mounting a transparent substrate on the gel, the transparent substrate having a second diffractive optical element on a surface.

15. The method of claim 14, wherein the second diffractive optical element comprises an array of diffractive optical elements.

16. The method of claim 11, further comprising arranging a lens adjacent to each light-emitting element inside the package.

17. The method of claim 11, further comprising allowing the gap to fill with air.

18. The method of claim 11, further comprising filling the gap with a gel material.

19. The method of claim 18, further comprising filling the gap with a gel material that is index matched to at least one of the window and the light-emitting elements.

20. A method comprising:

projecting partially collimated light from a lighting module to a target surface arranged at a distance from the lighting module so as to receive a uniform distribution of the partially collimated light, wherein the lighting module includes at least one array of light-emitting elements mounted on a substrate in a package; and

a window enclosing the package, the window having two surfaces and an array of diffractive optical elements mounted to one of the surfaces of the window such that a gap exists between the array of diffractive optical elements and the array of light-emitting elements, each diffractive optical element corresponding to a light-emitting element, the diffractive optical elements arranged to receive light from the light-emitting elements;

only partially collimating the light from the light-emitting elements via the diffractive optical elements; and

uniformly curing a material at the target surface in a predetermined amount of time.