Gimbaled micromechanical rotation system

• US 20040037492A1
• Filed: 08/20/2002
• Published: 02/26/2004
• Est. Priority Date: 08/20/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Smith, James H., Nasiri, Steven S., Kwon, Haesung, Novack, Mitchell J., Starr, James
• Granted Patent: US 6,843,574 B2
• Time in Patent Office: Days
• US Class Current: 385/18
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• 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 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/3564 Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
• 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

Abstract

The present invention is directed towards apparatuses for rotating a gimbaled platform with rotatable actuators. Gimbal springs comprised of component springs with compliant axes that intersect at a nonzero angle are coupled to the gimbaled platform. Preferably, the compliant axes of the component springs are oriented at an approximately 45 degree angle relative to the actuator rotation axes. Wraparound lever arms coupling the rotatable actuators with the gimbal springs serve to increase the leverage ratio, thereby permitting greater platform rotation for a given actuator rotation.

Claims

1. An apparatus, comprising:

a gimbaled platform capable of rotating about an x-axis and a y-axis, the intersection of the x-axis and y-axis defining a platform origin and a gimbal plane;

a first x-rotatable actuator capable of rotating about a first x-actuator axis, the first x-actuator axis being substantially parallel to the x-axis and disposed in the gimbal plane;

a first y-rotatable actuator capable of rotating about a first y-actuator axis, the first y-actuator axis being substantially parallel to the y-axis and disposed in the gimbal plane;

a first x-wraparound lever arm coupled to the first x-rotatable actuator;

a first y-wraparound lever arm coupled to the first y-rotatable actuator;

a first x-gimbal spring, coupling the first x-wraparound lever arm to the gimbaled platform, the first x-gimbal spring attaching to the gimbaled platform at a first x-gimbal-spring/gimbaled-platform attachment point; and

a first y-gimbal spring, coupling the first y-wraparound lever arm to the gimbaled platform, the first y-gimbal spring attaching to the gimbaled platform at a first y-gimbal-spring/gimbaled-platform attachment point;

wherein each gimbal spring comprises at least two component springs coupled in series, each of the component springs having a component compliant axis, the component compliant axis of the at least two component springs making a nonzero angle relative to each other; and

wherein the first x-rotatable actuator, the first x-wraparound lever arm, and the first x-gimbal spring are configured such that a positive rotation of the first x-rotatable actuator about the first x-actuator axis induces a positive rotation of the gimbaled platform about the x-axis and

wherein the first y-rotatable actuator, the first y-wraparound lever arm, and the first y-gimbal spring are configured such that a positive rotation of the first y-rotatable actuator about the first y-actuator axis induces a positive rotation of the gimbaled platform about the y-axis.

2. The apparatus, according to claim 1, wherein each component compliant axis of the component springs of at least one gimbal spring forms an angle of approximately 45 degrees with respect to both the x-axis and the y-axis.

3. The apparatus, according to claim 2, further comprising:

a second x-rotatable actuator capable of rotating about a second x-actuator axis, the second x-actuator axis being substantially parallel to the x-axis and disposed in the gimbal plane, the first x-actuator axis and the second x-actuator axis being on opposite sides of the x-axis;

a second y-rotatable actuator capable of rotating about a second y-actuator axis, the second y-actuator axis being substantially parallel to the y-axis and disposed in the gimbal plane, the first y-actuator axis and the second y-actuator axis being on opposite sides of the y-axis;

a second x-wraparound lever arm coupled to the second x-rotatable actuator;

a second y-wraparound lever arm coupled to the second y-rotatable actuator;

a second x-gimbal spring, coupling the second x-wraparound lever arm to the gimbaled platform; and

a second y-gimbal spring, coupling the second y-wraparound lever arm to the gimbaled platform;

wherein the second x-rotatable actuator, the second x-wraparound lever arm, and the second x-gimbal spring are configured such that a positive rotation of the second x-rotatable actuator about the second x-actuator axis induces a positive rotation of the gimbaled platform about the x-axis and

wherein the second y-rotatable actuator, the second y-wraparound lever arm, and the second y-gimbal spring are configured such that a positive rotation of the second y-rotatable actuator about the second y-actuator axis induces a positive rotation of the gimbaled platform about the y-axis.

4. The apparatus, according to claim 3, wherein the component compliant axes of the component springs of any of the gimbal springs intersect each other closer to the platform origin than the centroid of the respective gimbal spring in the gimbal plane.

5. The apparatus, according to claim 3, wherein the component compliant axes of the component springs of any of the gimbal springs intersect in the gimbaled platform.

6. The apparatus, according to claim 3, wherein each gimbal spring has a centroid in the gimbal plane, the centroid of any gimbal spring being further from the platform origin than the respective gimbal-spring/gimbal-platform attachment point.

7. The apparatus, according to claim 3, wherein at least one component spring of the at least one gimbal spring comprises at least one spring leg, each spring leg having a leg length measured parallel to the component compliant axis of the component spring, a leg width measured in the gimbal plane perpendicular to the component compliant axis, and a leg depth measured perpendicular to the gimbal plane, wherein the leg width is substantially greater than the leg depth.

8. The apparatus, according to claim 3, further comprising:

a post coupled to the gimbaled platform; and

a mirror coupled to the post.

9. The apparatus, according to claim 3, wherein at least one component spring of the at least one gimbal spring comprises at least one spring leg, each spring leg having a leg length measured parallel to the component compliant axis of the component spring, a leg width measured in the gimbal plane perpendicular to the component compliant axis, and a leg depth measured perpendicular to the gimbal plane wherein the leg depth is substantially greater than the leg width.

10. The apparatus, according to claim 9, wherein the at least one component spring comprises a plurality of substantially parallel spring legs joined in series;

adjacent spring legs being spaced apart by a spring-leg gap.

11. The apparatus, according to claim 10, wherein the mean spring-leg gap is less than approximately two times the leg width.

12. The apparatus, according to claim 10, wherein the mean spring-leg gap is less than approximately 3 μ

m.

13. The apparatus, according to claim 9, wherein the component springs of the at least one gimbal spring are coupled through a substantially rigid member.

14. The apparatus, according to claim 9, wherein the component springs of the at least one gimbal spring are coupled directly together.

15. The apparatus, according to claim 9, wherein the component springs of the at least one gimbal spring are coupled through a flexible member.

16. The apparatus, according to claim 9, wherein the component compliant axes of the component springs of any of the gimbal springs intersect each other closer to the platform origin than the centroid of the respective gimbal spring in the gimbal plane.

17. The apparatus, according to claim 1, wherein for at least one gimbal spring:

two component springs coupled in series form a component spring pair, the component compliant axes of the component springs in the component spring pair being approximately orthogonal and forming an approximately 45 degree angle with the x-axis and y-axis; and

wherein;

each component spring of the component spring pair comprises a spring leg having a leg length measured parallel to the component compliant axis of the component spring, a leg width measured in the gimbal plane perpendicular to the component compliant axis, and a leg depth measured perpendicular to the gimbal plane, the leg depth being substantially greater than the leg width.

18. The apparatus, according to claim 17, further comprising:

a second x-rotatable actuator capable of rotating about a second x-actuator axis, the second x-actuator axis being substantially parallel to the x-axis and disposed in the gimbal plane, the first x-actuator axis and the second x-actuator axis being on opposite sides of the x-axis;

a second y-rotatable actuator capable of rotating about a second y-actuator axis, the second y-actuator axis being substantially parallel to the y-axis and disposed in the gimbal plane, the first y-actuator axis and the second y-actuator axis being on opposite sides of the y-axis;

a second x-wraparound lever arm coupled to the second x-rotatable actuator;

a second y-wraparound lever arm coupled to the second y-rotatable actuator;

a second x-gimbal spring, coupling the second x-wraparound lever arm to the gimbaled platform; and

a second y-gimbal spring, coupling the second y-wraparound lever arm to the gimbaled platform;

wherein the second x-rotatable actuator, the second x-wraparound lever arm, and the second x-gimbal spring are configured such that a positive rotation of the second x-rotatable actuator about the second x-actuator axis induces a positive rotation of the gimbaled platform about the x-axis and

wherein the second y-rotatable actuator, the second y-wraparound lever arm, and the second y-gimbal spring are configured such that a positive rotation of the second y-rotatable actuator about the second y-actuator axis induces a positive rotation of the gimbaled platform about the y-axis.

19. The apparatus, according to claim 18, wherein the at least one gimbal spring further comprises a plurality of component spring pairs coupled in series.

20. The apparatus, according to claim 19, wherein spring legs in adjacent spring pairs are spaced apart by a mean spring-leg gap that is less than approximately two times the leg width.

21. The apparatus, according to claim 19, wherein spring legs in adjacent spring pairs are spaced apart by a mean spring-leg gap is less than approximately 3 μ

m.

22. The apparatus, according to claim 1, wherein the gimbaled platform forms a partial enclosure and at least one gimbal spring is disposed within the partial enclosure.

23. The apparatus, according to claim 22, wherein two component springs coupled in series form a component spring pair, the component compliant axis of the component springs in the component spring pair being approximately orthogonal and forming approximately 45 degree angles with the x-axis and y-axis.

24. The apparatus, according to claim 23, further comprising:

a second x-rotatable actuator capable of rotating about a second x-actuator axis, the second x-actuator axis being substantially parallel to the x-axis and disposed in the gimbal plane, the first x-actuator axis and the second x-actuator axis being on opposite sides of the x-axis;

a second y-rotatable actuator capable of rotating about a second y-actuator axis, the second y-actuator axis being substantially parallel to the y-axis and disposed in the gimbal plane, the first y-actuator axis and the second y-actuator axis being on opposite sides of the y-axis;

a second x-wraparound lever arm coupled to the second x-rotatable actuator;

a second y-wraparound lever arm coupled to the second y-rotatable actuator;

a second x-gimbal spring, coupling the second x-wraparound lever arm to the gimbaled platform; and

a second y-gimbal spring, coupling the second y-wraparound lever arm to the gimbaled platform;

wherein the second x-rotatable actuator, the second x-wraparound lever arm, and the second x-gimbal spring are configured such that a positive rotation of the second x-rotatable actuator about the second x-actuator axis induces a positive rotation of the gimbaled platform about the x-axis and

wherein the second y-rotatable actuator, the second y-wraparound lever arm, and the second y-gimbal spring are configured such that a positive rotation of the second y-rotatable actuator about the second y-actuator axis induces a positive rotation of the gimbaled platform about the y-axis.

25. The apparatus, according to claim 24, wherein for each gimbal spring:

each component spring of the-component spring pair comprises a spring leg having a leg length measured parallel to the component compliant axis of the component spring, a leg width measured in the gimbal plane perpendicular to the component compliant axis, and a leg depth measured perpendicular to the gimbal plane, the leg depth being substantially greater than the leg width.

26. The apparatus, according to claim 25, wherein each gimbal spring further comprises a plurality of component spring pairs coupled in series.

27. The apparatus, according to claim 1, further comprising:

a second x-rotatable actuator capable of rotating about a second x-actuator axis, the second x-actuator axis being substantially parallel to the x-axis and disposed in the gimbal plane, the first x-actuator axis and the second x-actuator axis being on opposite sides of the x-axis;

a second y-rotatable actuator capable of rotating about a second y-actuator axis, the second y-actuator axis being substantially parallel to the y-axis and disposed in the gimbal plane, the first y-actuator axis and the second y-actuator axis being on opposite sides of the y-axis;

a second x-wraparound lever arm coupled to the second x-rotatable actuator;

a second y-wraparound lever arm coupled to the second y-rotatable actuator;

a second x-gimbal spring, coupling the second x-wraparound lever arm to the gimbaled platform; and

a second y-gimbal spring, coupling the second y-wraparound lever arm to the gimbaled platform;

wherein the second x-rotatable actuator, the second x-wraparound lever arm, and the second x-gimbal spring are configured such that a positive rotation of the second x-rotatable actuator about the second x-actuator axis induces a positive rotation of the gimbaled platform about the x-axis and

wherein the second y-rotatable actuator, the second y-wraparound lever arm, and the second y-gimbal spring are configured such that a positive rotation of the second y-rotatable actuator about the second y-actuator axis induces a positive rotation of the gimbaled platform about the y-axis.

28. The apparatus, according to claim 27, further comprising:

a post coupled to the gimbaled platform; and

a mirror coupled to the post.

29. The apparatus, according to claim 27 wherein the component compliant axes of the at least two component springs of at least one gimbal spring are approximately orthogonal.

30. The apparatus, according to claim 29, wherein the maximum displacement of any component spring out of the gimbal plane is limited to 20 μ

m when the gimbaled platform is rotated 10 degrees.

31. The apparatus, according to claim 29, wherein at least one component spring of the at least one gimbal spring comprises at least one spring leg, each spring leg having a leg length measured parallel to the component compliant axis of the component spring, a leg width measured in the gimbal plane perpendicular to the component compliant axis, and a leg depth measured perpendicular to the gimbal plane wherein the leg width is substantially greater than the leg depth.

32. The apparatus, according to claim 31, wherein the component springs of the at least one gimbal spring are coupled through a substantially rigid member.

33. The apparatus, according to claim 31, wherein the component springs of the at least one gimbal spring are coupled directly together.

34. The apparatus, according to claim 31, wherein the component springs of the at least one gimbal spring are coupled through a flexible member.

35. An apparatus, comprising:

a gimbaled platform capable of rotating about an x-axis and a y-axis, the intersection of the x-axis and y-axis defining a platform origin and a gimbal plane;

a first x-rotatable actuator capable of rotating about a first x-actuator axis, the first x-actuator axis being substantially parallel to the x-axis and disposed in the gimbal plane;

a first y-rotatable actuator capable of rotating about a first y-actuator axis, the first y-actuator axis being substantially parallel to the y-axis and disposed in the gimbal plane;

a first x-lever arm coupled to the first x-rotatable actuator;

a first y-lever arm coupled to the first y-rotatable actuator;

a first x-gimbal spring, coupling the first x-lever arm to the gimbaled platform, the first x-gimbal spring attaching to the gimbaled platform at a first x-gimbal-spring/gimbaled-platform attachment point; and

a first y-gimbal spring, coupling the first y-lever arm to the gimbaled platform, the first y-gimbal spring attaching to the gimbaled platform at a first y-gimbal-spring/gimbaled-platform attachment point;

wherein at least one gimbal spring comprises at least two component springs coupled in series, each of the component springs having a component compliant axis, the component compliant axis of the at least two component springs making an angle of approximately 45 degrees relative to the x and y axes.

36. The apparatus, according to claim 35, further comprising:

a second x-rotatable actuator capable of rotating about a second x-actuator axis, the second x-actuator axis being substantially parallel to the x-axis and disposed in the gimbal plane, the first x-actuator axis and the second x-actuator axis being on opposite sides of the x-axis;

a second y-rotatable actuator capable of rotating about a second y-actuator axis, the second y-actuator axis being substantially parallel to the y-axis and disposed in the gimbal plane, the first y-actuator axis and the second y-actuator axis being on opposite sides of the y-axis;

a second x-lever arm coupled to the second x-rotatable actuator;

a second y-lever arm coupled to the second y-rotatable actuator;

a second x-gimbal spring, coupling the second x-lever arm to the gimbaled platform; and

a second y-gimbal spring, coupling the second y-lever arm to the gimbaled platform.

37. The apparatus, according to claim 36, further comprising:

a post coupled to the gimbaled platform; and

a mirror coupled to the post.

38. The apparatus, according to claim 36, wherein the component compliant axes of the component springs of the at least one gimbal spring intersect each other closer to the platform origin than the centroid of the respective gimbal spring in the gimbal plane.

39. The apparatus, according to claim 36, wherein the component compliant axes of the component springs of the at least one gimbal spring intersect in the gimbaled platform.

40. The apparatus, according to claim 36, wherein each gimbal spring has a centroid in the gimbal plane, the centroid of the at least one gimbal spring being further from the platform origin than the respective gimbal-spring/gimbaled-platform attachment point.

41. The apparatus, according to claim 36, wherein at least one component spring of the at least one gimbal spring comprises at least one spring leg that bends about an axis substantially parallel to the component compliant axis of the component spring.

42. The apparatus, according to claim 36, wherein at least one component spring of the at least one gimbal spring comprises at least one spring leg, each spring leg having a leg length measured parallel to the component compliant axis of the component spring, a leg width measured in the gimbal plane perpendicular to the component compliant axis, and a leg depth measured perpendicular to the gimbal plane wherein the leg width is substantially greater than the leg depth.

43. The apparatus, according to claim 42, wherein the component springs of the at least one gimbal spring are coupled through a substantially rigid member.

44. The apparatus, according to claim 42, wherein the component springs of the at least one gimbal spring are coupled directly together.

45. The apparatus, according to claim 42, wherein the component springs of the at least one gimbal spring are coupled through a flexible member.

46. The apparatus, according to claim 36, wherein at least one component spring comprises at least one spring leg that twists about an axis substantially parallel to the component compliant axis of the component spring.

47. The apparatus, according to claim 36, wherein at least one component spring of the at least one gimbal spring comprises at least one spring leg, each spring leg having a leg length measured parallel to the component compliant axis of the component spring, a leg width measured in the gimbal plane perpendicular to the component compliant axis, and a leg depth measured perpendicular to the gimbal plane wherein the leg depth is substantially greater than the leg width.

48. The apparatus, according to claim 47, wherein the at least one component spring comprises a plurality of substantially parallel spring legs joined in series;

adjacent spring legs being spaced apart by a spring-leg gap.

49. The apparatus, according to claim 48, wherein the mean spring-leg gap is less than approximately two times the leg width.

50. The apparatus, according to claim 48, wherein the mean spring-leg gap is less than approximately 3 μ

m.

51. The apparatus, according to claim 47, wherein the component springs of the at least one gimbal spring are coupled through a substantially rigid member.

52. The apparatus, according to claim 47, wherein the component springs of the at least one gimbal spring are coupled directly together.

53. The apparatus, according to claim 47, wherein the component springs of the at least one gimbal spring are coupled through a flexible member.

54. The apparatus, according to claim 47, wherein the component compliant axes of the component springs intersect in the gimbaled platform.

55. The apparatus, according to claim 36, wherein the maximum displacement of any component spring out of the gimbal plane is limited to 20 μ

m when the gimbaled platform is rotated 10 degrees.

56. The apparatus, according to claim 35, wherein for the at least one gimbal spring:

two component springs coupled in series form a component spring pair, the component compliant axes of the component springs in the component spring pair being approximately orthogonal and forming an approximately 45 degree angle with the x-axis and y-axis; and

wherein;

each component spring of the component spring pair comprises a spring leg having a leg length measured parallel to the component compliant axis of the component spring, a leg width measured in the gimbal plane perpendicular to the component compliant axis, and a leg depth measured perpendicular to the gimbal plane, the leg depth being substantially greater than the leg width.

57. The apparatus, according to claim 56, further comprising:

a second x-rotatable actuator capable of rotating about a second x-actuator axis, the second x-actuator axis being substantially parallel to the x-axis and disposed in the gimbal plane, the first x-actuator axis and the second x-actuator axis being on opposite sides of the x-axis;

a second y-rotatable actuator capable of rotating about a second y-actuator axis, the second y-actuator axis being substantially parallel to the y-axis and disposed in the gimbal plane, the first y-actuator axis and the second y-actuator axis being on opposite sides of the y-axis;

a second x-lever arm coupled to the second x-rotatable actuator;

a second y-lever arm coupled to the second y-rotatable actuator;

a second x-gimbal spring, coupling the second x-lever arm to the gimbaled platform; and

a second y-gimbal spring, coupling the second y-lever arm to the gimbaled platform.

58. The apparatus, according to claim 57, wherein the at least one gimbal spring further comprises a plurality of component spring pairs coupled in series.

59. The apparatus, according to claim 58, wherein spring legs in adjacent component spring pairs are spaced apart by a mean spring-leg gap that is less than approximately two times the leg width.

60. The apparatus, according to claim 58, wherein spring legs in adjacent component spring pairs are spaced apart by a mean spring-leg gap is less than approximately 3 μ

m.

61. The apparatus, according to claim 35, wherein the gimbaled platform forms a partial enclosure and the at least one gimbal spring is disposed within the partial enclosure.

62. The apparatus, according to claim 61, further comprising:

a second x-rotatable actuator capable of rotating about a second x-actuator axis, the second x-actuator axis being substantially parallel to the x-axis and disposed in the gimbal plane, the first x-actuator axis and the second x-actuator axis being on opposite sides of the x-axis;

a second y-rotatable actuator capable of rotating about a second y-actuator axis, the second y-actuator axis being substantially parallel to the y-axis and disposed in the gimbal plane, the first y-actuator axis and the second y-actuator axis being on opposite sides of the y-axis;

a second x-lever arm coupled to the second x-rotatable actuator;

a second y-lever arm coupled to the second y-rotatable actuator;

a second x-gimbal spring, coupling the second x-lever arm to the gimbaled platform; and

a second y-gimbal spring, coupling the second y-lever arm to the gimbaled platform.

63. The apparatus, according to claim 62, wherein:

two component springs coupled in series form a component spring pair, the component compliant axes of the component springs in the component spring pair being approximately orthogonal and forming an approximately 45 degree angle with the x-axis and y-axis; and

wherein;

each component spring of the component spring pair comprises a spring leg having a leg length measured parallel to the component compliant axis of the component spring, a leg width measured in the gimbal plane perpendicular to the component compliant axis, and a leg depth measured perpendicular to the gimbal plane, the leg depth being substantially greater than the leg width.

64. The apparatus, according to claim 63, wherein each gimbal spring further comprises a plurality of component spring pairs coupled in series.