Mechanical resonator for a rotation sensor

• US 6,561,028 B1
• Filed: 08/10/2000
• Issued: 05/13/2003
• Est. Priority Date: 08/10/1999
• Status: Expired due to Term

• Current Assignee: Infineon Technologies AG
• Original Assignee: Siemens AG
• Inventors: Sasse, Philipp, Aigner, Robert, Noe, Reinhold
• Primary Examiner(s): Larkin, Daniel S.
• Assistant Examiner(s): MILLER, ROSE MARY
• Application Number:
  US09/636,533
• Time in Patent Office: 1,006 Days
• Field of Search: 735/033, 735/040.2, 735/040.4, 735/040.8, 735/040.9, 735/041.1, 735/041.2, 735/041.4, 735/041.5, 735/041.8, 735/141.5, 735/141.6, 735/142.1, 735/143.2, 735/142.3, 735/143.6, 736/51, 310/365-371
• US Class Current: 73/504.11
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure

Abstract

Resonator which can be produced by micromachining and has a mass part (DF1, DF2, V1, V2) which is fixed by means of a resilient suspension (FA) to an anchoring point (AN) in such a way that it can perform rotary oscillations in its plane, in which, in the rest position of the mass part, the resilient suspension is aligned only along an axis (SAX) of symmetry with regard to which the mass part is of mirror-symmetrical design.

Claims

1. A mechanical resonator, comprising:

at least one resilient suspension;

at least one anchor;

a mass part layered predominantly in one plane and fixed by said resilient suspension to said at least one anchor for allowing rotary oscillations of said mass part about a rest position in said plane, said mass part having electrically conductive detection areas, said mass part to be rotated out of said plane about an axis running in said plane in said rest position, said axis being stationary relative to said at least one anchor, said mass part mirror image symmetrical in said plane about said axis when said mass part is in said rest position;

said at least one resilient suspension aligned along said axis in said rest position;

electrically conductive detection electrodes disposed opposite said detection areas in a direction perpendicular to said plane and immobile relative to said at least one anchor; and

electrically conductive negative feedback electrodes disposed opposite said detection areas in said perpendicular direction, immobile relative to said at least one anchor, and disposed and dimensioned to compensate for a torque that acts on said mass part about said axis when electrical potentials are applied to said feedback electrodes.

2. The resonator according to claim 1, wherein said at least one resilient suspension has a length and ends, and is a strip of resilient material fixed to said at least one anchor at one of said ends and to said mass part at another of said ends, and said mass part has, during a rotary oscillation, a center of gravity located at a distance from said at least one anchor equal to between at least a quarter and at most a half of said length of said resilient suspension.

3. The resonator according to claim 1, wherein, in said rest position, said mass part and said resilient suspension are mirror image symmetrical on another axis, and said another axis is disposed in said plane perpendicular to said axis.

4. The resonator according to claim 1, including a beam and a spring element connecting said at least one resilient suspension to said mass part.

5. The resonator according to claim 1, wherein:

said at least one anchor is two anchors;

said two anchors are disposed on said axis; and

said at least one resilient suspension is two suspensions each aligned along said axis and each fixed to a respective one of said two anchors; and

including;

beams fixed to each of said two suspensions; and

spring elements fixed to each of said beams and aligned along said axis, each of said spring elements being fixed to said mass part, each of said beams having a section and ends, said ends lying on said axis, said section of one of said beams running parallel to said section of another of said beams.

6. The resonator according to claim 4, wherein:

said at least one anchor is two anchors;

said two anchors are disposed on said axis; and

said at least one resilient suspension is two suspensions each aligned along said axis and each fixed to a respective one of said two anchors; and

including;

beams fixed to each of said two suspensions; and

spring elements fixed to each of said beams and aligned along said axis, each of said spring elements being fixed to said mass part, each of said beams having a section and ends, said ends lying on said axis, said section of one of said beams running parallel to said section of another of said beams.

7. The resonator according to claim 1, including electrodes for exciting a rotary oscillation, some of said electrodes being rigidly connected to said mass part, and some of said electrodes being fixed on said anchor, said electrodes forming a comb for electrostatically driving the resonator.

8. The resonator according to claim 1, wherein:

said detection areas are symmetrical with respect to said axis in said rest position;

said detection areas are electrically conductively connected through said at least one resilient suspension and said anchor; and

said detection electrodes and said mass part have a constant perpendicular projection configuration during rotary oscillation of the resonator; and

including another axis perpendicular to said axis, said perpendicular projection configuration is mirror image symmetrical in said rest position both with respect to said axis and with respect to said another axis.

9. The resonator according to claim 1, wherein said mass part has an electrically conductively configured portion, and including compensation electrodes immobile relative to said at least one anchor and disposed opposite said configured portion of said mass part in a direction perpendicular to said plane, an area of a perpendicular projection of said mass part onto a respective compensation electrode increasing or decreasing more than proportionally with an angle of rotation during a rotary oscillation with the angle of rotation in said plane.

10. The resonator according to claim 1, including at least one inertia body connected to said mass part and disposed, in said rest position, on said axis.

11. The resonator according to claim 1, wherein said electrically conductive negative feedback electrodes are disposed and dimensioned to compensate for a torque that acts on said mass part about said axis when electrical potentials are applied to said feedback electrodes.

12. A mechanical resonator, comprising:

at least one resilient suspension;

at least one anchor;

a mass part layered predominantly in one plane and fixed by said resilient suspension to said at least one anchor for allowing rotary oscillations of said mass part about a rest position in said plane, said mass part having electrically conductive detection areas, said mass part to be rotated out of said plane about an axis running in said plane in said rest position, said axis stationary relative to said at least one anchor, said mass part mirror image symmetrical in said plane about said axis when said mass part is in said rest position;

said at least one resilient suspension aligned along said axis in said rest position;

electrically conductive detection electrodes disposed opposite said detection areas in a direction along said axis and immobile relative to said at least one anchor; and

electrically conductive negative feedback electrodes disposed opposite said detection areas in a direction along said axis, immobile relative to said at least one anchor, and disposed and dimensioned to compensate for a torque that acts on said mass part about said axis when electrical potentials are applied to said feedback electrodes.

13. The resonator according to claim 12, wherein said electrically conductive negative feedback electrodes are disposed and dimensioned to compensate for a torque that acts on said mass part about said axis when electrical potentials are applied to said feedback electrodes.