Micromechanical rate-of-rotation sensor

• US 8,353,212 B2
• Filed: 07/31/2008
• Issued: 01/15/2013
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Hanking Electronics Hongkong Company Limited
• Original Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Inventors: Hammer, Hanno
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Shah, Samir M
• Application Number:
  US12/671,483
• Publication Number:
  US 20100199764A1
• Time in Patent Office: 1,629 Days
• Field of Search: 735/041.2, 734/88, 735/10, 735/141.2, 734/93, 735/140.1, 735/140.2
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure

Abstract

A micromechanical rate-of-rotation sensor for detecting a rate of rotation about a sense axis includes a substrate, a detection unit, means for generating a rotational oscillation of the detection unit about a drive axis which is orthogonal to the sense axis, and a central suspension means rotatably coupling the detection unit to the substrate in a fulcrum of the detection unit. The central suspension means is configured to permit the detection unit to perform a detection movement about a detection axis orthogonal to the sense axis in the form of a rotational oscillation about the central suspension means. The sensor also includes at least two second suspension means coupling the detection unit and the substrate for providing a response behavior specific to rotation about at least one of the drive axis and the detection axis.

Claims

1. A micromechanical rate-of-rotation sensor for detecting a rate of rotation about a sense axis, the sensor comprising:

a substrate;

a detection unit;

means for generating a rotational oscillation of the detection unit about a drive axis which is orthogonal to the sense axis;

a central suspension means rotatably coupling the detection unit to the substrate in a fulcrum of the detection unit, the central suspension means configured to permit the detection unit to perform a detection movement about a detection axis orthogonal to the sense axis in the form of a rotational oscillation about the central suspension means; and

at least two second suspension means coupling the detection unit and the substrate, the at least two second suspension means being anchored on the substrate along the sense axis for providing a controlled response behavior specific to rotation about at least one of the drive axis and the detection axis.

2. The micromechanical rate-of-rotation sensor of claim 1, wherein the at least two second suspension means are arranged on opposite sides of the fulcrum.

3. The micromechanical rate-of-rotation sensor of claim 1, wherein the at least two second suspension means are located diametrically opposite each other on a straight line extending through the central suspension means.

4. The micromechanical rate-of-rotation sensor of claim 1, wherein each of the second suspension means includes a spring element.

5. The micromechanical rate-of-rotation sensor of claim 4, wherein the spring element is configured as a bending beam.

6. The micromechanical rate-of-rotation sensor of claim 4, wherein the spring element includes a deformation compensating portion configured to compensate deformations in the spring element in a longitudinal direction.

7. The micromechanical rate-of-rotation sensor of claim 6, wherein the deformation compensating portion is one of meander-shaped, U-shaped, C-shaped, and annular.

8. The micromechanical rate-of-rotation sensor of claim 4, wherein the rigidity of the spring element is higher in a direction of deflection caused by a rate of rotation to be detected than in a direction orthogonal thereto.

9. The micromechanical rate-of-rotation sensor of claim 4, wherein the spring element has a substantially square cross-sectional shape and a high aspect ratio.

10. The micromechanical rate-of-rotation sensor of claim 4, wherein the spring element is connected to the detection unit at a first end that is radially remote from the central suspension means.

11. The micromechanical rate-of-rotation sensor of claim 10, wherein the spring element is connected to the substrate at an opposite, second end via an outer armature.

12. The micromechanical rate-of-rotation sensor of claim 11, wherein at least one of the first and second ends of the spring element is branched.

13. The micromechanical rate-of-rotation sensor of claim 12, wherein at least one of the first and second ends of the spring element is one of rounded and elliptically rounded.

14. The micromechanical rate-of-rotation sensor of claim 1, wherein the central suspension means includes a bending spring which substantially prevents rotational movement of the detection unit relative to the substrate about the sense axis and permits rotational movement in other directions.

15. The micromechanical rate-of-rotation sensor of claim 1, wherein the detection unit includes two wing-like protruding portions.

16. The micromechanical rate-of-rotation sensor of claim 15, wherein each of the second suspension means includes a spring element and a deformation compensating portion configured to compensate deformations in the spring element in a longitudinal direction, and wherein each of the wing-like protruding portions includes a recess in which the spring element and the deformation compensating portion is coupled to the detection unit.

17. The micromechanical rate-of-rotation sensor of claim 1, wherein the detection unit includes drive combs arranged in a radial direction.

18. The micromechanical rate-of-rotation sensor of claim 1, wherein the central suspension means includes a central armature and at least two bending springs, wherein each bending spring includes a first end coupled to the central armature and a second end coupled to the detection unit, and wherein at least one of the first and second ends of the respective bending springs is branched.

19. The micromechanical rate-of-rotation sensor of claim 1, wherein the central suspension means includes a central armature and at least two bending springs, wherein each bending spring includes a first end coupled to the central armature and a second end coupled to the detection unit, and wherein at least one of the first and second ends of the respective bending springs is one of rounded and elliptically rounded.