Micromirror having offset addressing electrode

• US 7,113,322 B2
• Filed: 09/21/2004
• Issued: 09/26/2006
• Est. Priority Date: 06/23/2004
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Reflectivity, Inc. (Texas Instruments, Inc.)
• Inventors: Patel, Satyadev
• Primary Examiner(s): Thompson, Timothy
• Assistant Examiner(s): FANG, JERRY C
• Application Number:
  US10/947,005
• Publication Number:
  US 20050286112A1
• Time in Patent Office: 735 Days
• Field of Search: 359/223, 359/224, 359/290, 359/291, 359/292, 359/295, 359/238
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

The micromirror device of the present invention comprises a reflective deflectable mirror plate and an addressing electrode provided for deflecting the mirror plate, wherein the addressing electrode is displaced along a direction perpendicular to the length of the hinge such that a portion of the addressing electrode is extended beyond the mirror plate.

Claims

1. A spatial light modulator device, comprising:

an array of micromirror devices, each of which comprises a minor plate operable to rotate above a substrate and an addressing electrode for rotating the minor plate, wherein an addressing electrode of a micromirror device in the array extends such that at least a portion of said addressing electrode is underneath the mirror plate of the adjacent micromirror device in the array.

2. The device of claim 1, wherein the electrode is at a position that is shifted along a direction parallel to an edge of the mirror plate when viewed from the top of the mirror plate.

3. The device of claim 1, wherein the mirror plate is attached to a hinge such that the mirror plate is operable to rotate asymmetrically.

4. The device of claim 3, wherein an attachment point of the mirror plate to the hinge is neither at a geometric center of the mirror plate nor on at least one of a plurality of diagonals of the mirror plate.

5. The device of claim 3, wherein the hinge is parallel to but offset from a diagonal of the mirror plate.

6. The device of claim 3, wherein the hinge is offset from but not parallel to a diagonal of the mirror plate.

7. The device of claim 3, wherein the hinge and the mirror plate are in different planes parallel to the substrate.

8. The device of claim 3, wherein the addressing electrode is displaced relative to the mirror plate such that the addressing electrode is extended beyond the mirror plate.

9. The device of claim 8, wherein the addressing electrode is extended beyond a furthest point of the mirror plate from the hinge along a direction perpendicular to the hinge.

10. The device of claim 9, wherein a displacement distance between a furthest point of the addressing electrode to the furthest point of the mirror plate is 1 micron or more, where in the furthest point of the mirror plate is a point having the largest distance from the binge, and wherein the furthest point of the addressing electrode having the largest distance from the hinge.

11. The device of claim 10, wherein the displacement distance is 2 microns or more.

12. The device of claim 10, wherein the displacement distance is 3 microns or more.

13. The device of claim 3, wherein a ratio of the displacement distance to a gap between the mirror plate and the hinge is 0.5 or more, wherein the displacement distance is a distance between a furthest point of the addressing electrode to the furthest point of the mirror plate, where in the furthest point of the mirror plate is a point having the largest distance from the hinge, and wherein the furthest point of the addressing electrode having the largest distance from the hinge.

14. The device of claim 13, wherein the ratio is 1.1 or more.

15. The device of claim 13, wherein the ratio is 1.2 or more.

16. The device of claim 13, wherein the ratio is from 1:

2 to 1;

4.

17. The device of claim 13, wherein the ratio is around 1:

3.

18. The device of claim 1, wherein the hinge and the mirror plate are in a same plane parallel to the substrate.

19. The device of claim 1, wherein the substrate is transmissive to visible light.

20. The device of claim 5, wherein the mirror plate is operable to rotate to an ON state angle of 12°

degrees or higher.

21. The device of claim 20, wherein the mirror plate is operable to rotate to an OFF state angle of −

2°

to −

6°

degrees.

22. The device of claim 1, wherein the mirror plate and the addressing electrode of at least one of the micromirror device of the array are positioned such that an imaginary line connecting a geometric center of the mirror plate and a geometric center of the addressing electrode is from 5°

to 50°

degrees relative to a line normal to the addressing electrode.

23. The device of claim 22, wherein the imaginary line connecting the geometric centers of the mirror plate and the addressing electrode has an angle with the normal of the addressing electrode, wherein the angle is from 10°

to 40°

degrees.

24. The device of claim 23, wherein the angle is from 15°

to 30°

degrees.

25. The device of claim 23, wherein the angle is from 15°

to 25°

degrees.

26. The device of claim 23, wherein a ratio of a vertical distance between the mirror plate and the addressing electrode to a length of the mirror plate is from 1:

1 to 1;

6.

27. A micromirror device, comprising:

a mirror plate operable to rotate on a substrate and an addressing electrode, wherein the addressing electrode is visible when viewed from directly above the mirror plate with the addressing electrode positioned underneath and offset from the mirror plate; and

wherein a ratio of a vertical distance between the mirror plate and the addressing electrode to a length of the mirror plate is from 1;

1 to 1;

6.

28. The device of claim 27, wherein the mirror plate is attached to a hinge such that the mirror plate is operable to rotate asymmetrically.

29. The device of claim 28, wherein an attachment point of the mirror plate to the hinge is neither at a geometric center of the mirror plate nor at a diagonal of the mirror plate.

30. The device of claim 29, wherein the hinge is parallel to but offset from a diagonal of the mirror plate.

31. The device of claim 29, wherein the hinge is offset from but not parallel to a diagonal of the mirror plate.

32. The device of claim 28, wherein the hinge and the mirror plate are in different planes parallel to the substrate.

33. The device of claim 32, wherein an imaginary line connecting a geometric center of the addressing electrode and a geometric center of the mirror plate is not normal to the addressing electrode.

34. The device of claim 33, wherein the addressing electrode is displaced relative to the mirror plate such tat the addressing electrode is extended beyond the mirror plate.

35. The device of claim 34, wherein the addressing electrode is extended beyond a furthest point of the mirror plate from the hinge along a direction perpendicular to the hinge.

36. The device of claim 34, wherein a displacement distance between a furthest point of the addressing electrode to the furthest point of the mirror plate is 1 micron or more, where in the furthest point of the mirror plate is a point having the largest distance from the hinge, and wherein the furthest point of the addressing electrode having the largest distance from the hinge.

37. The device of claim 36, wherein the displacement distance is 2 microns or more.

38. The device of claim 37, wherein the displacement distance is 3 microns or more.

39. The device of claim 36, wherein a ratio of the displacement distance to a gap between the mirror plate and the hinge is 0.5 or more, wherein the displacement distance is a distance between a furthest point of the addressing electrode to the furthest point of the mirror plate, where in the furthest point of the mirror plate is a point having the largest distance from the hinge, and wherein the furthest point of the addressing electrode having the largest distance from the hinge.

40. The device of claim 39, wherein the ratio is 1.1 or more.

41. The device of claim 40, wherein the ratio is 1.2 or more.

42. The device of claim 27, wherein the mirror plate is not deflected.

43. The device of claim 27, wherein said addressing electrode is a single addressing electrode associated with said mirror plate for rotating said mirror plate.

44. A spatial light modulator, comprising:

an array of micromirror devices of claim 27.