Driving a MEMS oscillator through a secondary set of support arms

• US 20080143451A1
• Filed: 02/12/2008
• Published: 06/19/2008
• Est. Priority Date: 05/14/2004
• Status: Abandoned Application

• Current Assignee: Microvision, Inc.
• Original Assignee: Microvision, Inc.
• Inventors: Brown, Dean R., Tauscher, Jason B., Montague, Thomas W., Sprague, Randall B., Davis, Wyatt O., Lewis, John R., Yan, Jun, Brown, Chancellor W.
• Application Number:
  US12/029,585
• Publication Number:
  US 20080143451A1
• Time in Patent Office: Days
• US Class Current: 331/157
• CPC Class Codes: G02B 26/085 the reflecting means being moved or deformed by electromagnetic means
• CPC Class Codes: G02B 26/0858 the reflecting means being moved or deformed by piezoelectric means
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129

Abstract

A MEMS oscillator, such as a MEMS scanner, has an improved and simplified drive scheme and structure. Drive impulses may be transmitted to an oscillating mass via torque through the support arms. For multi-axis oscillators drive signals for two or more axes may be superimposed by a driver circuit and transmitted to the MEMS oscillator. The oscillator responds in each axis according to its resonance frequency in that axis. The oscillator may be driven resonantly in some or all axes. Improved load distribution results in reduced deformation. A simplified structure offers multi-axis oscillation using a single moving body. Another structure directly drives a plurality of moving bodies. Another structure eliminates actuators from one or more moving bodies, those bodies being driven by their support arms.

Claims

1-25. -25. (canceled)

26. A MEMS oscillator, comprising:

a frame;

a first set of support arms coupled to the frame;

a gimbal coupled to the first set of support arms;

an actuator positioned to drive the gimbal to rotate around an axis defined by the first set of support arms;

a second set of support arms coupled to the gimbal; and

an oscillating body coupled to the second set of support arms to receive a drive impulse through the second set of support arms from the gimbal so as to be driven to oscillate around an axis defined by the second set of support arms.

27. The MEMS oscillator of claim 26, wherein;

the oscillating body is coupled to receive drive impulses at its resonance frequency through the second set of support arms; and

the oscillating body is positioned to oscillate at its resonance frequency.

28. The MEMS oscillator of claim 26, wherein the actuator is positioned to directly drive the gimbal.

29. The MEMS oscillator of claim 26, wherein the actuator is a moving coil magnetic actuator.

30. The MEMS oscillator of claim 26, wherein the actuator is a moving magnet magnetic actuator.

31. The MEMS oscillator of claim 26, wherein the actuator is an electrocapacitive actuator.

32. The MEMS oscillator of claim 26, wherein the first set of support arms comprises two torsion arms.

33. The MEMS oscillator of claim 26, wherein the second set of support arms comprises two torsion arms.

34. The MEMS oscillator of claim 33, wherein the second set of support arms are coupled to the oscillator body through at least one suspension element.

35. The MEMS oscillator of claim 26, wherein at least one of the first set of support arms and the second set of support arms is a single cantilevered arm.

36. The MEMS oscillator of claim 26, wherein the axis of rotation defined by the second set of support arms is transverse to the axis of rotation defined by the first set of support arms.

37. The MEMS oscillator of claim 36, wherein the axis of rotation defined by the second set of support arms is substantially at a right angle to the axis of rotation defined by the first set of support arms.

38. The MEMS oscillator of claim 26, wherein the oscillating body further comprises:

a second gimbal;

a third set of support arms coupled to the second gimbal;

a second oscillating body coupled to the third set of support arms to receive a drive impulse through the third set of support arms from the second gimbal so as to be driven to oscillate around an axis defined by the third set of support arms.

39. The MEMS oscillator of claim 26, wherein the oscillating body further includes a mirror positioned to receive a beam of light and deflect it across a field of view.

40-46. -46. (canceled)

47. A MEMS device, comprising:

an inner plate having a principal oscillatory mode at a first frequency;

an outer plate having a secondary oscillatory mode at the first frequency; and

a coupling between the inner plate and the outer plate selected to couple the first frequency secondary oscillatory mode of the outer plate to the first frequency principal oscillatory mode of the inner plate.

48. The MEMS device of claim 47, wherein the principal oscillatory mode of the inner plate includes rotation about an axis defined by the coupling.

49. The MEMS device of claim 48, further including a mirror surface on the inner plate.

50. The MEMS device of claim 48, wherein the outer plate includes a gimbal structure.

51. The MEMS device of claim 48, wherein the outer plate includes an anchor structure.

52. The MEMS device of claim 47, wherein the coupling includes a post.

53. The MEMS device of claim 47, wherein the coupling includes a bending flexure.

54. The MEMS device of claim 47, wherein the coupling includes at least one torsion arm.

55. The MEMS device of claim 47, where the coupling includes a suspension to distribute the coupled first frequency oscillatory force to a plurality of locations on the inner plate.

56. The MEMS device of claim 47, further comprising an actuator operable to induce the secondary oscillatory response in the outer plate at the first frequency.

57. The MEMS device of claim 47, wherein the outer plate also has a primary oscillatory response at a second frequency.

58. The MEMS device of claim 57, further comprising an actuator operable to induce in the outer plate a secondary oscillatory response at the first frequency and a primary oscillatory response at the second frequency.