MEMs display apparatus

• US 20080278798A1
• Filed: 10/19/2007
• Published: 11/13/2008
• Est. Priority Date: 02/23/2005
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Barton, Roger W., Hagood, Nesbitt W., Gandhi, Jignesh, Payne, Richard S., Fijol, John J., Steyn, Jasper Lodewyk, Fike, Eugene E. III
• Granted Patent: US 7,746,529 B2
• Time in Patent Office: Days
• US Class Current: 359/298
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38

Abstract

This invention relates to display apparatuses having an array of light modulators and a plurality of spacers distributed within the interior of the array. The display apparatus may also include a reflective aperture layer disposed on a front facing surface of a substrate included in the display apparatus.

Claims

1. A display apparatus comprising:

a first substrate;

a second substrate;

an array of MEMS light modulators formed on one of the first and second substrates; and

a rigid spacer located within the interior of the array, integrally formed from or connected to the first substrate at a first end and connected to a second substrate at a second end.

2. The display apparatus of claim 1, wherein the connection of the rigid spacer to one of the first and second substrates comprises a connection to a stack of at least one thin film deposited on the substrate.

3. The display apparatus of claim 2, wherein the thin film comprises one of a reflective aperture layer, a light absorbing layer, and a color filter.

4. The display apparatus of claim 1, wherein the rigid spacer is etched from the first substrate.

5. The display apparatus of claim 1, wherein the rigid spacer is etched from a film deposited on the first substrate.

6. The display apparatus of claim 1, wherein the first substrate and second substrates are substantially rigid.

7. The display apparatus of claim 1, wherein one of the first substrate and the second substrate is substantially rigid, and the other of the first substrate and the second substrate is substantially flexible.

8. The display apparatus of claim 1, wherein the rigid spacer is formed from an insulative material.

9. The display apparatus of claim 1, wherein the first substrate includes a front surface of a display device.

10. The display apparatus of claim 1, wherein the second substrate includes a front surface of a display device.

11. The display apparatus of claim 1, comprising a light guide distinct from the first and second substrates.

12. The display apparatus of claim 1, comprising a plurality of additional rigid spacers, wherein the rigid spacer and the plurality of additional rigid spacers are positioned within the array with a rigid spacer density less than or equal to one rigid spacer per four light modulators.

13. The display apparatus of claim 1, comprising a plurality of additional rigid spacers, wherein the MEMS light modulators correspond to respective display pixels, and wherein the each of the respective display pixels includes at least one rigid spacer.

14. The display apparatus of claim 1, wherein the rigid spacer forms an electrical connection between an electrical component on the first substrate to an electrical component on the second substrate.

15. The display apparatus of claim 1, wherein the rigid spacer is formed from a polymer.

16. The display apparatus of claim 1, wherein the rigid spacer is formed from a metal.

17. The display apparatus of claim 1, wherein the MEMS light modulators are configured to selectively obstruct the passage of light.

20. The display apparatus of claim 1, wherein the MEMS light modulators selectively extract light from a light guide.

21. The display apparatus of claim 1, wherein the rigid spacer limits a range of motion of a component in one of the MEMS light modulators.

22. The display apparatus of claim 1, wherein the rigid spacer interfits with an aligning element formed on the second substrate.

23. The display apparatus of claim 1, wherein at least one of the first substrate and the second substrate are substantially transparent.

24. The display apparatus of claim 1, wherein the rigid spacer is between about 1 micron and about 10 microns tall.

25. The display apparatus of claim 1, wherein the rigid spacer makes contact to a heat-reflowable material.

18. The display apparatus of claim 18, wherein the MEMS light modulators comprises shutter-based light modulators.

19. The display apparatus of claim 18, wherein the MEMS light modulators include electrowetting-based light modulators.

26. A display apparatus comprising:

a first substrate having a front-facing surface and a rear-facing surface;

a second substrate in front of the front-facing surface of the first surface;

a reflective aperture layer including a plurality of apertures disposed on the front-facing surface of the first substrate; and

a plurality of MEMS light modulators for modulating light directed towards the plurality of apertures to form an image.

27. The display apparatus of claim 26, wherein the first substrate comprises a light guide.

28. The display apparatus of claim 26, wherein the plurality of MEMS light modulators comprise shutter-based light modulators.

29. The display apparatus of claim 26, wherein the plurality of MEMS light modulators comprise electrowetting light modulators.

30. The display apparatus of claim 26, wherein the MEMS light modulators are disposed on the first substrate.

31. The display apparatus of claim 26, wherein the first substrate is transparent.

32. The display apparatus of claim 26, comprising a light guide positioned behind the first substrate, wherein the reflective aperture layer reflects light not passing through the plurality of apertures included in the reflective aperture layer back towards the light guide.

33. The display apparatus of claim 32, wherein the first substrate is in intimate contact with the light guide.

34. The display apparatus of claim 26, wherein the reflective aperture layer is formed from one of a mirror, a dielectric mirror, and a metallic film.

35. The display apparatus of claim 26, wherein the first substrate is positioned such that the reflective aperture layer is proximate the plurality of light modulators.

36. The display apparatus of claim 26, wherein the first substrate is positioned with respect to a light guide so as to form a gap between the first substrate and the light guide.

37. The display apparatus of claim 36, comprising a fluid filling the gap.

38. The display apparatus of claim 37, wherein the fluid has a first index of refraction and the light guide has a second index of refraction, and wherein the first index of refraction is less than that of the second index of refraction.

39. The display apparatus of claim 26, wherein the plurality of MEMS light modulators are formed on the second substrate.

40. The display apparatus of claim 39, wherein the plurality of MEMS light modulators are formed on a rear-facing surface of the second substrate.

41. The display apparatus of claim 26, comprising a control matrix formed on the second substrate for controlling the plurality of MEMS light modulators.

42. The display apparatus of claim 26, wherein the second substrate is transparent.

43. The display apparatus of claim 26, comprising mechanically interlocking features for maintaining lateral alignment between the first and second substrates.

44. The display apparatus of claim 26, comprising an adhesive for maintaining lateral alignment between the first and second substrates to less than 5 microns in any dimension.

45. The display apparatus of claim 44, wherein the adhesive comprises a heat-reflowable material

46. The display apparatus of claim 26, wherein the first substrate is positioned with respect to the second substrate so as to form a gap between the first substrate and the second substrate, the display apparatus comprising spacers for maintaining the gap.

47. The display apparatus of claim 46, comprising a fluid filling the gap.

48. The display apparatus of claim 46, comprising a liquid filling the gap.

49. The display apparatus of claim 47, wherein the fluid is a lubricant.

50. The display apparatus of claim 47, wherein the fluid has a first index of refraction and the substrate has a second index of refraction, and wherein the first index of refraction is greater than or substantially equal to that of the second index of refraction.