Replicated bragg selective diffractive element for display illumination

• US 20100141868A1
• Filed: 10/20/2009
• Published: 06/10/2010
• Est. Priority Date: 10/21/2008
• Status: Abandoned Application

• Current Assignee: Allview Research, LLC, Holux Technology Incorporated
• Original Assignee: Holux Technology Incorporated
• Inventors: Credelle, Thomas L., St. Hilaire, Pierre
• Application Number:
  US12/589,311
• Publication Number:
  US 20100141868A1
• Time in Patent Office: Days
• US Class Current: 349/62
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity

Abstract

A system for a display is disclosed. The system comprises an illumination source, a light guide, and a diffractive element. The illumination source inserts illumination into the light guide. The diffractive element extracts illumination from the light guide. The diffractive element comprises a modulated diffractive structure.

Claims

1. A system for a display, comprising:

an illumination source;

a light guide, wherein the illumination source inserts illumination into the light guide; and

a diffractive element, wherein the diffractive element extracts illumination from the light guide, and wherein the diffractive element comprises a slanted diffractive structure, wherein one or more properties of the slanted diffractive structure vary across a surface of the light guide.

2. A system as in claim 1, wherein one or more properties of the slanted diffracted structure comprise one or more of the following:

a height, a width, a shape, a pitch, an angle, an orientation, a spatial extent, and a wall thickness.

3. A system as in claim 1, wherein the modulated diffractive element comprises one or more slanted diffractive structures that were made using replication.

4. A system as in claim 1, wherein the diffractive element extracts light from a face of the light guide that is substantially perpendicular to an edge through which the illumination source inserts illumination into the light guide.

5. A system as in claim 1, further comprising a display, wherein the extracted illumination illuminates the display.

6. A system as in claim 5, wherein the extraction achieves a viewing angle for the illuminated display.

7. A system as in claim 5, wherein the extraction achieves a uniform light input for the illuminated display.

8. A system as in claim 5, wherein the extraction is based at least in part on a color of light being extracted.

9. A system as in claim 5, wherein the extraction comprises extraction of a broad set of colors.

10. A system as in claim 5, wherein the extraction is based at least in part on a striping of the display.

11. A system as in claim 5, wherein the extraction is aligned with a LCD color filter.

12. A system as in claim 5, wherein the extraction is based at least in part on a polarization of light being extracted.

13. A system as in claim 5, wherein the extraction is based at least in part on a position within the display.

14. A system as in claim 5, wherein two or more functions such as extraction efficiency, angle adjustment, color adjustment, polarization adjustment are combined in one diffractive element.

15. A system as in claim 5, wherein the slanted diffractive structures vary smoothly across the light guide surface.

16. A system as in claim 1, further comprising a monochrome display.

17. A system as in claim 16, wherein the monochrome display is enabled to have a color display.

18. A system as in claim 17, wherein the color display is at a lower resolution than the monochrome display.

19. A system as in claim 1, wherein the light guide for the illumination source recycles polarized light.

20. A system as in claim 1, wherein the extracted illumination provides a front light to the display.

21. A system as in claim 1, wherein the extracted illumination provides a back light for the display.

22. A system as in claim 1, wherein the diffractive element is positioned on a side of the light guide that is closest to a display.

23. A system as in claim 1, wherein the diffractive element is positioned on a side of the light guide that is farthest from a display.

24. A method for a display, comprising:

providing an illumination source;

providing a light guide, wherein the illumination source inserts illumination into the light guide; and

providing a diffractive element, wherein the diffractive element extracts illumination from the light guide, and wherein the diffractive element comprises a modulated diffractive structure.