Vertical comb drive actuated deformable mirror device and method

• US 6,384,952 B1
• Filed: 03/27/1998
• Issued: 05/07/2002
• Est. Priority Date: 03/27/1997
• Status: Expired due to Term

• Current Assignee: Mems Optical, Inc. (Jenoptik AG)
• Original Assignee: Mems Optical, Inc. (Jenoptik AG)
• Inventors: Clark, Rodney L., Hammer, Jay A., Karpinsky, John R.
• Primary Examiner(s): Phan, James
• Application Number:
  US09/049,121
• Time in Patent Office: 1,502 Days
• Field of Search: 359/196-199, 359/201, 359/212-214, 359/223, 359/224, 310/309
• US Class Current: 359/224.1
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 2203/0136 Comb structures
• CPC Class Codes: B81B 2203/053 Translation according to an axis perpendicular 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: B81B 3/0086 Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 26/06 for controlling the phase of light G02B26/08 takes precedence , measuring optical phase difference G01J9/00
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A deformable mirror includes a vertical comb actuator having a reflective surface attached thereto. The vertical comb drive includes stationary elements interspersed with moving elements. When a potential difference is provided between these elements, the moving elements are pulled downward, thereby deforming the reflective surface. The vertical comb drive typically includes a plurality of actuators, which are individually electrically addressed. Each actuator may be an array of interspersed elements or a cavity and corresponding tooth. Springs support the moving elements and bias the reflective surface in an original position. The vertical comb drive provides a large stroke and substantially linear voltage-versus-displacement curve throughout the stroke.

Claims

1. A deformable mirror comprising:

a vertical comb drive;

a reflective surface attached to said vertical comb drive; and

a spring for biasing said vertical comb drive to maintain said reflective surface in an original position absent application of a voltage to said vertical comb drive.

2. A deformable mirror comprising:

a vertical electrostatic comb drive including a first array of stationary elements and a second array of moving elements correspondingly interspersed with said first array;

a reflective surface attached to said second array;

a layer covering tops of elements of said second array; and

a spring for suspending said first array relative to said second array, said spring being attached to said layer.

3. The deformable mirror according to claim 2 wherein said stationary elements and said movable elements are circular.

4. The deformable mirror according to claim 2, wherein said stationary elements and said movable elements are planar.

5. The deformable mirror according to claim 2, wherein said layer is attached directly to said reflective surface.

6. The deformable mirror according to claim 2, wherein voltage is applied to each stationary element of said first array individually or each moving element of said second array individually.

7. The deformable mirror according to claim 2, wherein said vertical electrostatic comb drive comprises plurality of cavities and teeth interdigitally mounted with said cavities, said reflective surface being attached to said teeth.

8. The deformable mirror according to claim 7, further comprising a top layer between the teeth and the reflective surface.

9. The deformable mirror according to claim 7, further comprising a conductor for individually connecting each tooth of said teeth to a voltage source.

10. A deformable mirror comprising:

a vertical electrostatic comb drive;

a reflective surface attached to said vertical comb drive, wherein said vertical comb drive comprises a first array of stationary elements and a second array of moving elements correspondingly interspersed with said first array, said reflective surface being attached to said second array and defining a plane;

said vertical comb drive, when actuated, displacing said surface in a direction orthogonal to the plane thereof;

a layer covering tops of elements of said second array; and

a post attaching said layer to said reflective surface.

11. The deformable mirror according to claim 10, wherein said post is in a center of said reflective surface.

12. A deformable mirror comprising:

a vertical electrostatic comb drive including an array of vertical comb actuators, wherein said vertical comb drive includes a first array of stationary elements and a second array of moving elements correspondingly interspersed with said first array;

a reflective surface attached to said vertical comb drive, said reflective surface being attached to said second array and defining a plane, said reflective surface being displaced in a direction orthogonal to the plane thereof when said vertical comb drive is actuated; and

springs for individually suspending each of said second array of each actuator in said array.

13. The deformable mirror according to claim 12, further comprising an anchor for supporting said springs.

14. A displaceable surface comprising:

a vertical electrostatic comb drive;

a surface attached to said vertical comb drive and defining a plane; and

a spring for biasing said vertical comb drive to maintain said surface in an original position absent application of a voltage to said vertical comb drive;

said vertical comb drive, when actuated, displacing said surface in a direction orthogonal to the plane thereof.

15. The displaceable surface of claim 14, wherein said surface is reflective.

16. A displaceable surface comprising:

a vertical electrostatic comb drive;

a surface attached to said vertical comb drive, wherein said vertical comb drive comprises a first array of stationary elements and a second array of moving elements correspondingly interspersed with said first array, said surface defining a plane and being attached to said second array, said surface being displaced in a direction orthogonal to the plane thereof when said vertical electrostatic comb drive is actuated;

a layer covering tops of elements of said second array; and

a spring for suspending said first array relative to said second array, said spring being attached to said layer.

17. The displaceable surface of claim 16 wherein the vertical electrostatic comb drive is provided on a substrate and said surface is generally parallel to said substrate.

18. The displaceable surface of claim 16 wherein said displaceable surface includes plural vertical electrostatic comb drives to which said surface is attached, each said vertical electrostatic comb drive locally displacing said surface in a direction generally orthogonal to a plane generally defined by said surface.

19. The displaceable surface of claim 18 wherein said plural actuators are driven to tilt said surface.

20. The displaceable surface of claim 16 further comprising a mirror mounted substantially parallel to said surface.

21. The displaceable surface according to claim 16, wherein said stationary elements and said movable elements are circular.

22. The displaceable surface according to claim 16, wherein said stationary elements and said movable elements are planar.

23. The displaceable surface according to claim 16, wherein said layer is attached directly to said surface.

24. The displaceable surface according to claim 16, wherein voltage is applied to each stationary element of said first array individually or each moving element of said second array individually.

25. The displaceable surface according to claim 16, wherein said vertical comb drive comprises an array of vertical comb actuators.

26. The displaceable surface according to claim 25, means for individually providing voltage to each actuator of said array.

27. The displaceable surface according to claim 16, wherein said vertical comb drive comprises plurality of cavities and teeth interdigitally mounted with said cavities, said surface being attached to said teeth.

28. The displaceable surface according to claim 27, further comprising a top layer between the teeth and the surface.

29. The displaceable surface according to claim 27, further comprising a conductor for individually connecting each tooth of said teeth to a voltage source.

30. The displaceable surface of claim 16, wherein said surface is reflective.

31. A displaceable surface comprising:

a vertical electrostatic comb drive;

a surface attached to said vertical comb drive, wherein said vertical comb drive comprises a first array of stationary elements and a second array of moving elements correspondingly interspersed with said first array, said surface defining a plane and being attached to said second array, said surface being displaced in a direction orthogonal to the plane thereof when said vertical electrostatic comb drive is actuated;

a layer covering tops of elements of said second array; and

a post attaching said layer to said surface.

32. The displaceable surface according to claim 31, wherein said post is in a center of said surface.

33. A displaceable surface comprising:

a vertical electrostatic comb drive including an array of vertical comb actuators;

a surface attached to said vertical comb drive, wherein said vertical comb drive comprises a first array of stationary elements and a second array of moving elements correspondingly interspersed with said first array, said surface defining a plane and being attached to said second array, said surface being displaced in a direction orthogonal to the plane thereof when said vertical electrostatic comb drive is actuated; and

springs for individually suspending each of said second array of each actuator in said array.

34. The displaceable surface according to claim 33, further comprising an anchor for supporting said springs.