System and method for providing a uniform backlight

• US 7,976,184 B2
• Filed: 04/22/2010
• Issued: 07/12/2011
• Est. Priority Date: 06/07/2006
• Status: Active Grant

• Current Assignee: Omron Corporation
• Original Assignee: Microscan Systems Inc (Omron Corporation)
• Inventors: Bergeron Dunn, Sheila, Messina, Michael C.
• Primary Examiner(s): Lee; Diane I
• Assistant Examiner(s): McMillan; Jessica L
• Application Number:
  US12/765,701
• Publication Number:
  US 20100232157A1
• Time in Patent Office: 446 Days
• Field of Search: 362/235, 362/311, 362/332, 362/633, 362/224, 362/225, 362/612, 362/294, 362/373
• US Class Current: 362/235
• CPC Class Codes: F21S 2/005 of modular construction
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

An illumination system includes an illumination source such as an array of LED'"'"'s over which is provided a diffuser. The illumination source provides light which, because of light refraction, radiates generally uniformly from edge to edge of the diffuser. The diffuser may be a planar flat piece of may include a hollow, cup like structure formed by a frame with a cover. The illumination system may be scaled up to provide multiple such illumination devices side by side to provide a greater area or strength of illumination. Multiple systems may utilize multiple diffusers or a single diffuser covering multiple illumination sources. The illumination source may be mounted to a backplate or heatsink which is larger than the illumination source to facilitate the addition of further electronic circuitry and or mounting capabilities.

Claims

1. An illumination module comprising:

one or more light sources mounted on a substrate; and

a diffuser comprising;

a frame having a proximal end and a distal end, and

a front cover attached to the distal end;

wherein the proximal end of the frame is removably attached to the substrate.

2. The illumination module of claim 1 wherein a hollow volume is formed between the substrate and the diffuser and the one or more light sources are enclosed within the hollow volume.

3. The illumination module of claim 1, further comprising a heat sink attached to the back of the substrate.

4. The illumination module of claim 1 wherein the frame is removably attached around the perimeter of the substrate.

5. The illumination module of claim 1 wherein the frame comprises a quadrilateral set of walls.

6. The illumination module of claim 5 wherein the length and width of the frame substantially correspond to the length and width of the substrate.

7. The illumination module of claim 5 wherein at least one of the length and width of the substrate exceeds the corresponding length or width of the frame.

8. The illumination module of claim 1 wherein the frame and the front cover are made of a transparent material.

9. The illumination module of claim 1 wherein the front cover is substantially flat and evenly diffuses light from the one or more light sources.

10. The illumination module of claim 9 wherein the diffuser provides uniform illumination using internal refraction of light within the diffuser.

11. The illumination module of claim 9, further comprising providing uniform illumination using internal refraction of light within the diffuser.

12. The illumination module of claim 1 wherein the substrate is a printed circuit board.

13. A modular illumination system comprising:

two or more illumination modules, each illumination module comprising a substrate having one or more light sources mounted thereon, wherein the two or more illumination modules are coupled to each other along their respective edges; and

a single diffuser comprising a frame having a proximal end and a distal end, and a front cover attached to the distal end, wherein the proximal end of the frame is removably attached to the two or more illumination modules.

14. The modular illumination system of claim 13 wherein a hollow volume is formed between the substrates and the single diffuser and the light sources are enclosed within the hollow volume.

15. The modular illumination system of claim 13 wherein the single diffuser is removably attached around the perimeter of the coupled illumination modules.

16. The modular illumination system of claim 13 wherein the two or more illumination modules are coupled to a backing plate.

17. The modular illumination system of claim 16 wherein the backing plate is a heat sink.

18. The modular illumination system of claim 13 wherein the front cover is substantially flat and evenly diffuses light from the one or more light sources.

19. The modular illumination system of claim 13 wherein the diffuser provides uniform illumination using internal refraction of light within the diffuser.

20. A process comprising:

mounting one or more light sources on a substrate; and

removably attaching a diffuser to the substrate, the diffuser comprising;

a frame having a proximal end and a distal end, and

a front cover attached to the distal end;

wherein the proximal end of the frame is removably attached to the substrate.

21. The process of claim 20 wherein a hollow volume is formed between the substrate and the diffuser and the one or more light sources are enclosed within the hollow volume.

22. The process of claim 20, further comprising attaching a heat sink to the back of the substrate.

23. The process of claim 20 wherein the frame is removably attached around the perimeter of the substrate.

24. The process of claim 20 wherein the frame comprises a quadrilateral set of walls.

25. The process of claim 24 wherein the length and width of the frame substantially correspond to the length and width of the substrate.

26. The process of claim 24 wherein at least one of the length and width of the substrate exceeds the corresponding length or width of the frame.

27. The process of claim 20 wherein the frame and the front cover are made of a transparent material.

28. The process of claim 20 wherein the front cover is substantially flat and evenly diffuses light from the one or more light sources.