MEMS mirror with tip or piston motion for use in adaptive optics

• US 20060066964A1
• Filed: 09/29/2004
• Published: 03/30/2006
• Est. Priority Date: 09/29/2004
• Status: Active Grant

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Greywall, Dennis S.
• Granted Patent: US 7,344,262 B2
• Time in Patent Office: Days
• US Class Current: 359/849
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

An array of high fill factor mirrors has each mirror be coupled across two deformable spring bars that are deformed using a drive. The two deformable springs are parallel to each other, and coupled together, e.g., by a cross bar. A support is coupled at one end to the cross bar and at its opposite end to the mirror. Coupled across the deformable spring bars on the opposite side thereof from the mirror support, is at least one moveable drive plate. Motion by the moveable drive plate causes the deformable spring bars to torque, e.g., in the local vicinity of the connection of the drive plate to the deformable spring bars. The torque causes the deformable spring bars to move downward, e.g., near their centers. As a result, cross bar, and hence the mirror, move downward.

Claims

1. A micro-electromechanical systems (MEMS) device, comprising:

a plurality of spaced deformable spring bars, each of said deformable spring bars being coupled together at least at a first surface thereof; and

a first moveable drive plate coupled to said deformable spring bars on a surface of said deformable spring bars opposite to first surface, said first moveable drive plate being adapted to cause said deformable spring bars to torque in a local vicinity of their coupling location to said drive plate.

2. The invention as defined in claim 1 wherein said deformable spring bars are substantially parallel.

3. The invention as defined in claim 1 further comprising a plate coupled to at least two of said spring bars and said moveable drive plate.

4. The invention as defined in claim 1 wherein said deformable spring bars are coupled by cross bar.

5. The invention as defined in claim 4 wherein said cross bar has at least one slit therein.

6. The invention as defined in claim 4 further comprising:

a support coupled at a first end thereof to said cross bar; and

a plate coupled to said support at a second end thereof that is opposite to said first end.

7. The invention as defined in claim 6 wherein said support is a post.

8. The invention as defined in claim 6 wherein said plate is a mirror.

9. The invention as defined in claim 6 wherein said plate has a shape selected from one of the set of shapes consisting of:

substantially square, substantially rectangular, substantially hexagonal, substantially round.

10. The invention as defined in claim 1 where said first moveable drive plate is part of a first comb drive.

11. The invention as defined in claim 1 wherein said first moveable drive plate is part of a first flat plate drive.

12. The invention as defined in claim 1 wherein at least one of said deformable spring bars is supported at both of its ends.

13. The invention as defined in claim 1 wherein each of said deformable spring bars are supported at both of their ends.

14. The invention as defined in claim 1 wherein said deformable spring bars are supported at at least one end.

15. The invention as defined in claim 1 wherein said deformable spring bars are supported at at least one end by a wall.

16. The invention as defined in claim 15 wherein said wall is adapted to operate as an electrical shield.

17. The invention as defined in claim 1 further comprising a fixed drive plate mated to said moveable drive plate.

18. The invention as defined in claim 17 wherein said fixed drive plate is electrically isolated from said moveable drive plate, whereby a potential difference may exist between said fixed drive plate and said moveable drive plate.

19. The invention as defined in claim 1 wherein said moveable drive plate is coupled to said deformable spring bars about midway between an end of said deformable spring bars and the middle of said deformable spring bars.

20. The invention as defined in claim 1 wherein said cross bar is split at least partway across.

21. The invention as defined in claim 1 further comprising a second moveable drive plate coupled to said deformable spring bars on a surface of said deformable spring bars opposite to said first surface.

22. The invention as defined in claim 21 wherein said first moveable drive plate and said second moveable drive plate are both coupled to said deformable spring bars between the same end of said deformable spring bars and the middle of said deformable spring bars.

23. The invention as defined in claim 21 wherein said first moveable drive plate is coupled to said deformable spring bars between a first end of said deformable spring bars and the middle of said deformable spring bars and said second moveable drive plate is coupled to said deformable spring bars between a second end of said deformable spring bars that is opposite to said first end and the middle of said deformable spring bars.

24. The invention as defined in claim 21 wherein said first moveable drive plate and said second moveable drive plate are arranged so that said torque applied by each in said local vicinity of their respective coupling locations to said drive plate is additive.

25. The invention as defined in claim 21 wherein said first moveable drive plate and said second moveable drive plate are each part of respective comb drives, and wherein the further each of said comb drives is coupled from a point at which said deformable spring bars are coupled to a plate, the longer are the combs of said comb drives.

26. The invention as defined in claim 21 wherein said first moveable drive plate and said second moveable drive plate are each part of respective comb drives arranged so that said torque applied by each of their respective moveable drive plates in said local vicinity of their respective coupling locations to said deformable spring bars is additive, and wherein the further each of said comb drives is coupled from a point at which said deformable spring bars are coupled to a plate, the longer are the combs of said comb drives.

27. A micro-electromechanical systems (MEMS) device, comprising:

at least one deformable spring bar coupled at a first surface thereof to a plate; and

a first moveable drive plate coupled to said at least one deformable spring bar on a surface thereof opposite to said first surface, said first moveable drive plate being adapted to cause said at least one deformable spring bar to torque in a local vicinity of its coupling location to said drive plate.

28. The invention as defined in claim 27 wherein said at least one deformable spring bar is one of a plurality of deformable spring bars.

29. The invention as defined in claim 28 wherein said at least deformable spring bar one deformable spring bar and at least one other of said plurality of deformable spring bars are substantially parallel to each other.

30. The invention as defined in claim 28 wherein at least one other of said plurality of deformable spring bars is also coupled to said first moveable drive plate.

31. A micro-electromechanical systems (MEMS) device, comprising:

deformable support means, said deformable support means including at least one deformable spring bar; and

drive means coupled to one surface of said deformable support means to cause said deformable support means to torque in a local vicinity of their coupling location to said drive means.

32. The invention as defined in claim 31 further comprising a plate coupled to said deformable support means on a surface opposite to said one surface.

33. The invention as defined in claim 32 further wherein deformation of said deformable support means induces piston motion by said plate.

34. The invention as defined in claim 32 further wherein deformation of said deformable support means induces tilt motion by said plate.

35. The invention as defined in claim 31 wherein said deformable support means is supported from at least one wall mounted on a substrate.

37. The invention as defined in claim 31 wherein said deformable support means is a plurality of spaced deformable spring bars.

38. The invention as defined in claim 31 wherein said drive means is an electrostatic drive.

39. The invention as defined in claim 38 wherein said electrostatic drive is a comb drive.

40. The invention as defined in claim 38 wherein said electrostatic drive is a flat plate drive.

36. (canceled)