Coupling apparatus for inertial sensors

• US 7,347,094 B2
• Filed: 04/14/2005
• Issued: 03/25/2008
• Est. Priority Date: 04/14/2004
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Clark, William A., Kuang, Jinbo, Geen, John A.
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US11/106,354
• Publication Number:
  US 20050229703A1
• Time in Patent Office: 1,076 Days
• Field of Search: 735/040.2, 735/040.4, 735/041.2, 735/041.3, 735/041.4, 735/041.5, 735/041.6, 735/10, 735/143.2, 735/142.9, 735/143.8, 738/625.9
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion

Abstract

A coupling apparatus allows anti-phase movements of inertial sensor element frames along parallel axes but substantially prevents in-phase movements of the frames. The coupling apparatus includes a bar coupled between first and second sensor element frames and at least one supporting structure supporting the bar. The at least one structure is coupled to a substrate underlying the frames. The structures allow the bar to rotate at a pivot point when the frames move in anti-phase to one another along substantially parallel axes but substantially prevent in-phase movements of the frames.

Claims

1. Apparatus for coupling sensor elements of an inertial sensor, the apparatus comprising:

a bar coupled between first and second sensor element frames; and

a plurality of anchor flexures supporting the bar above a substrate underlying the frames, each anchor flexure including a structure anchored at one end to the substrate and folded back 180 degrees to meet with the bar, the anchor flexures allowing the bar to rotate at a pivot point when the frames move in anti-phase to one another along separate substantially parallel axes but substantially preventing in-phase movements of the frames, wherein the anchor flexures are anchored adjacent to the bar about the pivot point.

2. Apparatus according to claim 1, further comprising:

a first pair of short flexures extending from one of the frames and interconnected by a first long flexure; and

a second pair of short flexures extending from the other of the frames and interconnected by a second long flexure, wherein the bar interconnects the first long flexure to the second long flexure substantially at midpoints of the first and second long flexures.

3. Apparatus according to claim 2, wherein each of the long flexures is coupled so as to flex as the bar rotates.

4. Apparatus according to claim 1, further comprising:

a first flexure extending from one of the frames; and

a second flexure extending from the other of the frames, wherein the bar interconnects the first and second flexures.

5. Apparatus according to claim 4, wherein the plurality of anchor flexures includes four anchor flexures positioned around the pivot point.

6. Apparatus according to claim 4, wherein each of the first and second flexures includes two substantially parallel members coupled at both ends, one of the members coupled to the frame, the other member coupled to the bar, the members coupled so as to flex as the bar rotates.

7. Apparatus according to claim 1, wherein rotation of the substrate about an axis normal to the plane causes the movements of the frames.

15. Apparatus according to claim 1, further comprising:

a plurality of balancers coupled to the frames such that each frame includes a balancer coupled on a side opposite to the bar.

8. Apparatus for coupling sensor elements of an inertial sensor, the apparatus comprising:

coupling means for coupling first and second sensor element frames; and

supporting means for supporting the coupling means above a substrate underlying the frames, the supporting means including a plurality of anchor flexures, each anchor flexure including a structure anchored at one end to the substrate and folded back 180 degrees to meet with the coupling means, the supporting means allowing the coupling means to rotate at a pivot point when the frames move in anti-phase to one another along separate substantially parallel axes but substantially preventing in-phase movements of the frames, wherein the anchor flexures are anchored adjacent to the coupling means about the pivot point.

9. Apparatus according to claim 8, wherein the coupling means comprises:

a first pair of short flexures extending from one of the frames and interconnected by a first long flexure;

a second pair of short flexures extending from the other of the frames and interconnected by a second long flexure; and

a bar that interconnects the first long flexure to the second long flexure substantially at midpoints of the first and second long flexures.

10. Apparatus according to claim 9, wherein each of the long flexures is coupled so as to flex as the bar rotates.

11. Apparatus according to claim 8, wherein the coupling means comprises:

a first flexure extending from one of the frames;

a second flexure extending from the other of the frames; and

a bar that interconnects the first and second flexures.

12. Apparatus according to claim 8, wherein the supporting means includes four anchor flexures positioned around the pivot point.

13. Apparatus according to claim 11, wherein each of the first and second flexures includes two substantially parallel members coupled at both ends, one of the members coupled to the frame, the other member coupled to the bar, the members coupled so as to flex as the bar rotates.

14. Apparatus according to claim 8, wherein rotation of the substrate about an axis normal to the plane causes the movements of the frames.

16. Apparatus according to claim 8, further comprising:

balancing means coupled to the frames opposite the coupling means.