Capacitively coupled resonator drive

• US 20070144257A1
• Filed: 12/22/2005
• Published: 06/28/2007
• Est. Priority Date: 12/22/2005
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Meyer, Robert
• Granted Patent: US 7,467,553 B2
• Time in Patent Office: Days
• US Class Current: 73/514.320
• CPC Class Codes: G01P 15/097 by vibratory elements
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

An apparatus and method for a micro-machined device having a movable mass rotatably suspended from a frame by one or more hinges for rotation relative thereto frame. A DETF resonator is suspended between the frame and reaction mass, and a capacitor is provided between the frame and movable mass for transmitting a drive signal to the DETF resonator.

Claims

1. A micro-machined device, comprising:

a movable mass rotatably suspended from a frame by one or more hinges for rotation relative to the frame;

a DETF resonator suspended between the frame and reaction mass; and

a capacitor between the frame and movable mass.

2. The device of claim 1 wherein the capacitor further comprises a pair of spaced-apart capacitor plates between the frame and movable mass.

3. The device of claim 2 wherein the capacitor further comprises a body mounted on the frame and having one of the pair of spaced-apart capacitor plates mounted thereon.

4. The device of claim 3 wherein the capacitor body further spans a gap between the frame and movable mass.

5. The device of claim 1, further comprising an electronic drive circuit coupled to the capacitor.

6. The device of claim 5 wherein the electronic drive circuit is structured to apply an alternating current electronic drive signal to the capacitor.

7. The device of claim 1 wherein the capacitor plates of the capacitor are further mounted substantially crosswise to both a hinge axis of the one or more hinges and an input axis of the movable mass.

8. The device of claim 7 wherein the capacitor plates of the capacitor are further mounted spaced away from hinge axis of the one or more hinges along the input axis of the movable mass.

9. A micro-machined device, comprising:

a frame and pendulous mass formed of a substrate, the pendulous mass being substantially coplanar with and spaced away from the frame;

a hinge coupled between the frame and pendulous mass rotationally suspends the pendulous mass for relative rotational motion about a hinge axis in response to a force experienced along an input axis;

a DETF resonator suspended between the frame and the reaction mass in a push/pull relationship; and

a capacitor arranged between the frame and pendulous mass and spaced away from the hinge.

10. The device of claim 9 wherein the substrate further comprises first and second opposing substantially parallel spaced-apart planar surfaces;

and

the capacitor is further positioned between the spaced-apart planar surfaces.

11. The device of claim 10 wherein the capacitor further comprises a body mounted on the frame and spanning a gap between the frame and pendulous mass, and

a pair of spaced-apart capacitor plates between the body and pendulous mass.

12. The device of claim 9, further comprising an electronic drive circuit coupled to the capacitor.

13. The device of claim 12 wherein the electronic drive circuit is structured to apply an alternating current electronic drive signal to the capacitor.

14. The device (100) of claim 12 wherein the DETF resonator further comprises two substantially parallel and spaced-apart tines attached between opposite mounting tabs, the mounting tabs being mounted on frame and pendulous mass, respectively.

15. The device of claim 9, further comprising an electrically conductive path between the capacitor and the DETF resonator.

16. A micro-machined device, comprising:

a frame formed of a silicon semiconductor substrate having first and second opposing substantially parallel spaced-apart planar surfaces;

a pendulous mass formed in the substrate coplanar with and spaced away from the frame by a gap;

a hinge coupled between the frame and pendulous mass rotationally suspends the pendulous mass for relative rotational motion about a hinge axis in response to a force experienced along an input axis;

a DETF resonator suspended between the frame and the reaction mass in a push/pull relationship; and

a capacitor spanning the gap between the frame and pendulous mass and arranged substantially crosswise of the hinge and input axes and spaced away from the hinge axis toward one of the first and second substrate surfaces.

17. The device of claim 16 wherein the capacitor is further mounted on respective side surfaces of frame and pendulous mass positioned between the spaced-apart planar surfaces substantially crosswise of the hinge axis and input axis.

18. The device of claim 17 wherein the capacitor further comprises a body mounted on the frame and spanning the gap between the frame and pendulous mass, and

a pair of capacitor plates spaced-apart across a capacitor gap between the body and pendulous mass, one of the capacitor plates being coupled to each of the body and the pendulous mass.

19. The device of claim 18, further comprising an electronic drive circuit coupled to the capacitor, the electronic drive circuit being structured to apply an alternating current electronic drive signal to the capacitor.

20. The device of claim 16, further comprising an electrically conductive path between the capacitor and the DETF resonator.