MEMS display apparatus

• US 7,746,529 B2
• Filed: 10/19/2007
• Issued: 06/29/2010
• 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
• Primary Examiner(s): Choi; William C
• Application Number:
  US11/975,398
• Publication Number:
  US 20080278798A1
• Time in Patent Office: 984 Days
• Field of Search: 359/198, 359/230, 359/233, 359/290, 359/199.4, 359/200.4
• US Class Current: 359/233
• 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 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;

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

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.

2. The display apparatus of claim 1, wherein the first substrate comprises a light guide.

3. The display apparatus of claim 1, wherein the plurality of MEMS light modulators comprise shutter-based light modulators.

4. The display apparatus of claim 1, wherein the plurality of MEMS light modulators comprise electrowetting light modulators.

5. The display apparatus of claim 1, wherein the MEMS light modulators are disposed on the first substrate.

6. The display apparatus of claim 1, wherein the first substrate is transparent.

7. The display apparatus of claim 1, wherein the first substrate is in intimate contact with the light guide.

8. The display apparatus of claim 1, wherein the reflective aperture layer is formed from one of a mirror, a dielectric mirror, and a metallic film.

9. The display apparatus of claim 1, wherein the first substrate is positioned such that the reflective aperture layer is proximate the plurality of light modulators.

10. The display apparatus of claim 1, 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.

11. The display apparatus of claim 10, comprising a fluid filling the gap.

12. The display apparatus of claim 11, 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.

13. The display apparatus of claim 1, wherein the plurality of MEMS light modulators are formed on the second substrate.

14. The display apparatus of claim 13, wherein the plurality of MEMS light modulators are formed on a rear-facing surface of the second substrate.

15. The display apparatus of claim 1, comprising a control matrix formed on the second substrate for controlling the plurality of MEMS light modulators.

16. The display apparatus of claim 1, wherein the second substrate is transparent.

17. The display apparatus of claim 1, comprising mechanically interlocking features for maintaining lateral alignment between the first and second substrates.

18. The display apparatus of claim 1, comprising an adhesive for maintaining lateral alignment between the first and second substrates to less than 5 microns in any dimension.

19. The display apparatus of claim 18, wherein the adhesive comprises a heat-reflowable material.

20. The display apparatus of claim 1, 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.

21. The display apparatus of claim 20, comprising a fluid filling the gap.

22. The display apparatus of claim 21, wherein the fluid is a lubricant.

23. The display apparatus of claim 21, 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.

24. The display apparatus of claim 20, comprising a liquid filling the gap.

25. 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;

a plurality of MEMS light modulators for modulating light directed towards the plurality of apertures to form an image, wherein the first substrate comprises a light guide.

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;

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

27. 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;

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

28. 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;

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

mechanically interlocking features for maintaining lateral alignment between the first and second substrates.

29. 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;

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

an adhesive for maintaining lateral alignment between the first and second substrates to less than 5 microns in any dimension.

30. The display apparatus of claim 29, wherein the adhesive comprises a heat-reflowable material.

31. The display apparatus of claim 30, wherein the lubricant 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.

32. 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, 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;

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

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

a fluid filling the gap, wherein the fluid is a lubricant.