LIGHT-GUIDE APPARATUS

• US 20110044073A1
• Filed: 05/22/2009
• Published: 02/24/2011
• Est. Priority Date: 05/23/2008
• Status: Active Grant

• Current Assignee: Design LED Products Limited (Forvia SE)
• Original Assignee: Design LED Products Limited (Forvia SE)
• Inventors: Gourlay, James
• Granted Patent: US 9,086,516 B2
• Time in Patent Office: Days
• US Class Current: 362/607
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity

Abstract

A light-guide apparatus comprising a light-guide plate for guiding light rays and a plurality of light extraction features is described. The light extraction features comprise a transparent material applied to the light-guide plate so as to form an uneven surface. The transparent material may comprise a textured ink applied to the surface of the light-guide plate via a printing process. The incorporation of an uneven surface provides mirco-lens like elements on the surface of the extraction feature which have a higher aspect ratio and so lend themselves to the refraction of the light out of the light-guide plate. In this way a device is produced wherein the size, height, location and surface profile of the extraction features can be carefully controlled. As a result the described light-guide apparatus provides for a highly efficient and relatively uniform light output.

Claims

1. A light-guide apparatus comprising a light-guide plate for guiding light rays and a plurality of light extraction features, the light extraction features comprising a transparent material applied to the light-guide plate and having an uneven surface such that light rays incident upon the uneven surface are refracted out of the light guide.

2. A light-guide apparatus as claimed in claim 1 wherein the uneven surface comprises at least one micro lens-like element.

3. A light-guide apparatus as claimed in claim 1 wherein the plurality of light extraction features are discontinuous upon the light-guide plate.

4. A light-guide apparatus as claimed in claim 1 wherein the plurality of light extraction features are arranged in an array upon the surface of the light-guide plate.

5. A light-guide apparatus as claimed in claim 4 wherein the array comprises a regular array.

6. A light-guide apparatus as claimed in claim 4 wherein the volume of the light extraction features increase from one side of the array to the other.

7. A light-guide apparatus as claimed in claim 6 wherein the volume increases by incorporating light extraction features of increasing size.

8. A light-guide apparatus as claimed in claim 6 wherein the volume is increased by incorporating light extraction features of increasing height.

9. A light-guide apparatus as claimed in claim 1 wherein the light extraction features comprise lines across the light-guide plate.

10. A light-guide apparatus as claimed in claim 1 wherein the light extraction features are dots.

11. A light-guide apparatus as claimed in claim 1 wherein the transparent material is a printed transparent material applied to the light-guide plate by a printing process.

12. A light-guide apparatus as claimed in claim 1 wherein the transparent material comprises a transparent textured ink.

13. A light-guide apparatus as claimed in claim 1 wherein the transparent material has the same or similar refractive index to that of the light-guide plate.

14. A light-guide apparatus as claimed in claim 1 wherein the light-guide plate comprises a transparent polymer sheet.

15. A display comprising a light-guide apparatus as claimed in claim 1.

16. A display as claimed in claim 15 wherein the display further comprises a reflecting means provided spaced apart from one side of the light-guide plate for reflecting light extracted towards the reflecting means towards the other side of the light-guide plate.

17. A display as claimed in claim 16 wherein the reflecting means comprises a specular or non-specular reflector.

18. A display as claimed in claim 15 wherein the display further comprises a diffusing means arranged on one side of the light-guide means in the direction that the display will be viewed from.

19. A display as claimed in claim 18 wherein a reflecting means is arranged on the opposite side of the light-guide from the diffusing means.

20. A method of manufacturing a light-guide apparatus having one or more extraction features comprising the steps of:

applying a transparent material onto a surface of light-guide so as to define the position of the one or more extraction features; and

drying or curing the transparent material such that the surface of the transparent material is uneven.

21. A method of manufacturing a light-guide apparatus as claimed in claim 20 wherein the uneven surface comprise at least one micro lens-like element.

22. A method of manufacturing a light-guide apparatus as claimed in claim 20 wherein the plurality of light extraction features are applied discontinuously on to the light-guide plate.

23. A method of manufacturing a light-guide apparatus as claimed in claim 20 wherein the plurality of light extraction features are applied to form an array upon a surface of the light-guide plate.

24. A method of manufacturing a light-guide apparatus as claimed in claim 23 wherein the array comprises a regular array.

25. A method of manufacturing a light-guide apparatus as claimed in claim 23 wherein the plurality of light extraction features are applied such that the volume of the light extraction features increase from one side of the array to the other.

26. A method of manufacturing a light-guide apparatus as claimed in claim 25 wherein the volume is increased by incorporating light extraction features of increasing size.

27. A method of manufacturing a light-guide apparatus as claimed in claim 25 wherein the volume is increased by incorporating light extraction features of increasing height.

28. A method of manufacturing a light-guide apparatus as claimed in claim 20 wherein the step of applying the plurality of light extraction features comprises printing of the transparent material.

29. A method of manufacturing a light-guide apparatus as claimed in claim 28 wherein the printing of the transparent material comprise a screen printing process.

30. A method of manufacturing a light-guide apparatus as claimed in claim 20 wherein the transparent material is a textured transparent ink.

31. (canceled)