Light concentrating reflective display methods and apparatus

• US 7,616,368 B2
• Filed: 02/23/2006
• Issued: 11/10/2009
• Est. Priority Date: 02/23/2005
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Hagood, Nesbitt W. IV
• Primary Examiner(s): Lester; Evelyn A.
• Application Number:
  US11/362,422
• Publication Number:
  US 20060250676A1
• Time in Patent Office: 1,356 Days
• Field of Search: 385/43, 353 30- 32, 353/94, 353/98, 353/99, 345/84, 345/85, 345/87, 345/102, 345/108, 345/109, 362/97.3, 362/231, 362/241, 362341-350, 348/740, 348/750, 348/756, 348/770, 348/771, 399/221, 399 3- 6, 359/223, 359/224, 359290-292, 359/295, 359/298, 359/454, 359/455, 359/459, 359/627, 359/628, 359/726, 359/727
• US Class Current: 359/290
• CPC Class Codes: G02B 17/002 Arrays of reflective systems
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B

Abstract

Improved apparatus and methods for displays are disclosed that utilize light concentration array between mechanical light modulators and the viewing surface of the display. The light concentration array includes an array of optical elements that concentrate light on respective ones of the light modulators to maximize the contrast ratio and off axis viewing of the display.

Claims

1. A display apparatus comprising:

an array of light modulators for selectively reflecting light towards a viewer to form an image;

an array of reflective light funnels disposed between the array of light modulators and the viewer, for concentrating light on respective ones of the light modulators in the array of light modulators; and

an array of color filters corresponding to respective ones of the light modulators.

2. The display apparatus of claim 1, wherein one of the reflective light funnels in the array of reflective light funnels comprises a first optical opening directed towards the viewer, a second, smaller optical opening directed towards a respective one of the light modulators, and a reflective wall connecting the first optical opening to the second optical opening.

3. The display apparatus of claim 2, wherein the reflective wall comprises a reflective material deposited on the interior of the reflective light funnel.

4. The display apparatus of claim 2, wherein the wall is generally conical in shape.

5. The display of the of claim 2, wherein the wall comprises a polygonal cross section.

6. The display apparatus of claim 2, wherein the height of the reflective light funnel is greater than the diameter of the first optical opening.

7. A display apparatus comprising:

an array of MEMS-based light modulators for selectively modulating light to form an image, one of the MEMS-based light modulators comprising a shutter, wherein the shutter

comprises a reflective material for reflecting light towards a viewer, and

selectively obstructs light from impacting a light-absorbing surface behind the shutter with respect to the viewer; and

an array of reflective light funnels disposed between the array of MEMS-based light modulators and a viewer, for concentrating light on respective ones of the light modulators in the array of light modulators.

8. The display apparatus of claim 7, comprising a backlight.

9. The display apparatus of claim 7, comprising a front light.

10. The display apparatus of claim 7, wherein the one MEMS-based light modulator comprises a second shutter.

11. The display apparatus of claim 10, wherein the first shutter covers a larger area surface than the second shutter.

12. The display apparatus of claim 7, comprising an array of color filters corresponding to respective ones of the light modulators.

13. The display apparatus of claim 12, wherein the array of color filters includes a plurality of red filters, green filters, and blue filters.

14. The display apparatus of claim 12, wherein the array of color filters includes a plurality of white filters.

15. The display apparatus of claim 7, wherein one of the reflective light funnels in the array of reflective light funnels comprises a first optical opening directed towards the viewer, a second, smaller optical opening directed towards a respective one of the light modulators, and a reflective wall connecting the first optical opening to the second optical opening.

16. The display apparatus of claim 15, wherein the reflective wall comprises a reflective material deposited on the interior of the reflective light funnel.

17. The display apparatus of claim 15, wherein the reflective wall comprises a substantially transparent interior coated by a reflective material.

18. The display apparatus of claim 15, wherein the wall is generally conical in shape.

19. The display apparatus of claim 15, wherein the wall has a hexagonal cross section.

20. The display apparatus of claim 15, wherein the wall has a rectangular cross section.

21. The display apparatus of claim 15, wherein the wall comprises a polygonal cross section.

22. The display apparatus of claim 15, wherein the height of the one reflective light funnel is smaller than the diameter of the first optical opening.

23. The display apparatus of claim 15, wherein the height of the one reflective light funnel is greater than the diameter of the first optical opening.

24. A display apparatus comprising:

an array of MEMS-based light modulators for selectively modulating light to form an image, one of the MEMS-based light modulators comprising a shutter, wherein the shutter comprises a light-absorbing material; and

an array of reflective light funnels disposed between the array of MEMS-based light modulators and a viewer, for concentrating light on respective ones of the light modulators in the array of light modulators.

25. The display apparatus of claim 24, comprising a backlight.

26. The display apparatus of claim 25, wherein the MEMS-based light modulators selectively transmit light from the backlight towards the viewer and selectively reflect light originating from the direction of the viewer.

27. The display apparatus of claim 24, comprising a front light.

28. The display apparatus of claim 24, wherein the shutter selectively obstructs light from impacting a reflective surface behind the shutter with respect to the viewer.

29. The display apparatus of claim 24, wherein the one MEMS-based light modulator comprises a second shutter.

30. The display apparatus of claim 29, wherein the first shutter covers a larger area surface than the second shutter.

31. The display apparatus of claim 24, comprising an array of color filters corresponding to respective ones of the light modulators.

32. The display apparatus of claim 31, wherein the array of color filters includes a plurality of red filter, green filters, and blue filters.

33. The display apparatus of claim 31, wherein the array of color filters includes a plurality of white filters.

34. The display apparatus of claim 24, wherein one of the reflective light funnels in the array of reflective light funnels comprises a first optical opening directed towards the viewer, a second, smaller optical opening directed towards a respective one of the light modulators, and a reflective wall connecting the first optical opening to the second optical opening.

35. The display apparatus of claim 34, wherein the reflective wall comprises a reflective material deposited on the interior of the reflective light funnel.

36. The display apparatus of claim 34, wherein the reflective wall comprises a substantially transparent interior coated by a reflective material.

37. The display apparatus of claim 34, wherein the wall is generally conical in shape.

38. The display apparatus of claim 34, wherein the wall has a hexagonal cross section.

39. The display apparatus of claim 34, wherein the wall has a rectangular cross section.

40. The display apparatus of claim 34, wherein the wall comprises a polygonal cross section.

41. The display apparatus of claim 34, wherein the height of the one reflective light funnel is smaller than the diameter of the first optical opening.

42. The display apparatus of claim 34, wherein the height of the one reflective light funnel is greater than the diameter of the first optical opening.