Micro-mirror with rotor structure

• US 7,019,876 B2
• Filed: 07/29/2002
• Issued: 03/28/2006
• Est. Priority Date: 07/29/2002
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Yang, Xiaofeng
• Primary Examiner(s): Phan, James
• Application Number:
  US10/208,590
• Publication Number:
  US 20040017599A1
• Time in Patent Office: 1,338 Days
• Field of Search: None
• US Class Current: 359/221.2
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 2203/0109 Bridges
• CPC Class Codes: B81B 2203/056 Rotation in a plane parallel to the substrate
• CPC Class Codes: B81B 3/0062 Devices moving in two or more dimensions, i.e. having special features which allow movement in more than one dimension
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/352 the reflective optical element having a shaped reflective surface, e.g. a reflective element comprising several reflective surfaces or facets that function together
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: Y10S 359/904 Micromirror

Abstract

A micro-mirror device includes a stator structure having a set of radial stator electrodes, a rotor structure having a set of radial rotor electrodes, a mirror mounted on the rotor structure, and a flexure structure suspending the rotor structure relative to the stator structure.

Claims

1. A micro-mirror device, comprising:

a stator structure having a set of radial stator electrodes;

a rotor structure having a set of radial rotor electrodes;

a mirror mounted on the rotor structure; and

a flexure structure suspending the rotor structure relative to the stator structure.

2. The device of claim 1, wherein the stator structure is defined on a first substrate, and the rotor structure and the flexure structure are defined on a second substrate.

3. The device of claim 2, wherein the rotor structure has a generally circular periphery, and said flexure structure is a serpentine structure defined from said second substrate.

4. The device of claim 3, further comprising a driver circuit electrically connected to the stator electrodes and the rotor electrodes for imparting rotary electrostatic forces tending to rotate the rotor about an axis of rotation, and a conductor trace connecting the driver circuit to the rotor electrodes, said conductor trace passing over said flexure structure.

5. The device of claim 2, wherein the flexure structure is defined by voids in said second substrate.

6. The device of claim 2, wherein the flexure structure comprises a plurality of radially extending beam portions defined from said second substrate.

7. The device of claim 2, wherein the mirror structure is fabricated on said second substrate.

8. The device of claim 7, wherein said mirror structure includes a mirror plane defined along a crystal plane of said second substrate.

9. The device of claim 8, wherein said mirror structure includes a reflective coating layer applied to said mirror plane.

10. The device of claim 1, further comprising a driver circuit electrically connected to the stator electrodes and the rotor electrodes for imparting rotary electrostatic forces tending to rotate the rotor about an axis of rotation.

11. The device of claim 10, wherein said rotor has a rest position, and said driver circuit has a state which tends to drive the rotor to a driven position.

12. A display device including the micro-mirror device of claim 1.

13. The display device of claim 12, wherein the display device is a raster-scanning display system.

14. An optical switch including the micro-mirror device of claim 1.

15. A spatial light modulator including the micro-mirror device of claim 1.

16. A method of using the micro mirror device of claim 1, comprising:

applying an alternating pattern of fixed voltages to arrays of the rotor electrodes, wherein each rotor array consists of an even number Nr of rotor electrodes;

applying a substantially alternating pattern of voltages to arrays of the stator electrodes, wherein each stator array consists of an odd number Ns of stator electrodes;

introducing a local disruption in the substantially alternating pattern of voltages applied to the stator arrays to generate a radial electrostatic force tending to rotate the rotor.

17. An array of micro mirrors, comprising:

a plurality of micro mover devices, each having a micro mirror for selectively deflecting an input beam of light from an input device to an output device;

each said micro mover device comprising;

a stator structure having a set of radial stator electrodes;

a rotor structure having a set of radial rotor electrodes, the mirror mounted on the rotor structure;

a flexure structure suspending the rotor structure relative to the stator structure.

18. The array of claim 17, wherein the plurality of micro movers are arranged along a linear array axis as a one dimensional array.

19. The array of claim 17, wherein the plurality of micro movers are arranged in a two dimensional array.

20. The array of claim 19, wherein the plurality of micro movers are arranged in rows and columns.

21. The device of claim 17, wherein the stator structure of each of the plurality of micro movers is defined on a common first substrate, and the rotor structure and the flexure structure of each of the plurality of micro movers are defined on a common second substrate.

22. The device of claim 21, wherein the rotor structure for each micro mover has a generally circular periphery.

23. The device of claim 22, wherein the flexure structure for each micro mover is a serpentine structure defined from said second substrate.

24. The device of claim 22, wherein the flexure structure for each micro mover comprises a plurality of radially extending beam portions.

25. The array of claim 17, further comprising a control circuit connected to the plurality of micro mover devices providing voltages to control the position of the micro mirror of each micro mover device.

26. The device of claim 25, wherein the control circuit is electrically connected to the stator electrodes and the rotor electrodes for each micro mover for imparting rotary electrostatic forces tending to rotate the rotor about an axis of rotation.

27. The device of claim 21, wherein the flexure structure is defined by voids in said second substrate.

28. The device of claim 21, wherein the micro mirror of each micro mover is fabricated on said second substrate.

29. The device of claim 28, wherein the micro mirror of each micro mover is on a mirror plane defined along a crystal plane of said second substrate.

30. A micro mirror device, comprising:

a stator structure having a set of radial stator electrodes;

a rotor structure having a set of radial rotor electrodes;

a mirror mounted on the rotor structure; and

means for suspending the rotor structure relative to the stator structure and allowing radial movement of the rotor structure in a range of movement about a rotor axis.

31. The device of claim 30, wherein the stator structure is defined on a first substrate, and the rotor structure is defined on a second substrate.

32. The device of claim 31, wherein said suspending means comprises a flexure structure defined by voids formed in the second substrate.

33. The device of claim 32, wherein the rotor structure has a generally circular periphery, and said flexure structure is a serpentine structure defined from said second substrate.

34. The device of claim 32, wherein rotor structure has a generally circular periphery, and the flexure structure comprises a plurality of radially extending beam portions defined from said second substrate.

35. The device of claim 31, further comprising a driver circuit electrically connected to the stator electrodes and the rotor electrodes for imparting rotary electrostatic forces tending to rotate the rotor about said axis of rotation.

36. The device of claim 31, wherein the mirror structure is fabricated on said second substrate.

37. The device of claim 31, wherein said mirror structure includes a mirror plane defined along a crystal plane of said second substrate.

38. A raster-scanning display system, comprising:

a generator for generating an optical beam;

a first micro mirror device responsive to line control signals for deflecting the optical beam along a line to produce a first deflected beam;

a second micro mirror device responsive to frame control signals for deflecting the first deflected beam to produce a second deflected beam;

a controller for controlling the generator and for producing the line control signals and the frame control signals;

the first and second micro mirror devices each including;

a stator structure having a set of radial stator electrodes;

a rotor structure having a set of radial rotor electrodes;

a mirror mounted on the rotor structure; and

a flexure structure suspending the rotor structure relative to the stator structure.

39. A display system, comprising:

a generator for generating an optical beam;

a first micro mirror device responsive to first control signals for deflecting the optical beam to produce a first deflected beam;

a fixed mirror system for redirecting the first deflected beam as a second deflected beam;

a second micro mirror device responsive to second control signals for deflecting the second deflected beam to produce a third deflected beam;

a controller for controlling the generator and for producing the first and second control signals;

the first and second micro mirror devices each including;

a stator structure having a set of radial stator electrodes;

a rotor structure having a set of radial rotor electrodes;

a mirror mounted on the rotor structure; and

a flexure structure suspending the rotor structure relative to the stator structure.

40. The system of claim 39, wherein the stator structure of each of the first and second micro mirror devices is defined on a common first substrate, and the rotor structure and the flexure structure of each of the plurality of micro mirror devices are defined on a common second substrate.