Microgyroscope

• US 8,429,970 B2
• Filed: 06/25/2009
• Issued: 04/30/2013
• Est. Priority Date: 06/27/2008
• Status: Active Grant

• Current Assignee: Hanking Electronics Hongkong Company Limited
• Original Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Inventors: Rocchi, Alessandro
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Shah, Samir M
• Application Number:
  US13/001,126
• Publication Number:
  US 20110094301A1
• Time in Patent Office: 1,405 Days
• Field of Search: 735/041.2, 735/033, 735/040.2, 735/140.2, 735/143.2, 735/040.8
• US Class Current: 73/504.08
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion

Abstract

A microgryroscope for determining rotational movements about an x, y or z axis. At least one anchor is fastened to a substrate. A plurality of, in particular four, masses that oscillate radially with respect to the anchor are fastened to the anchor by springs. Drive elements are used to vibrate at least individual ones of the masses in an oscillatory manner in the x or y direction in order to produce Coriolis forces when the substrate is deflected. Sensor elements are used to detect deflections of the masses on account of the Coriolis forces produced. The oscillating masses are connected to at least one additional, non-oscillating mass which can, however, rotate together with the oscillating masses on the substrate about the at least one anchor. A further sensor element is associated with this additional mass.

Claims

1. A microgyroscope for determining rotational movements around an x-axis, a y-axis or a z-axis, comprising:

a substrate on which at least one anchor is fastened,

a plurality of individual oscillating masses, each of said plurality of individual oscillating masses being configured to radially oscillate with respect to said at least one anchor, wherein each of said plurality of individual oscillating masses is fastened to the at least one anchor with at least one spring,

driving elements for oscillating said plurality of individual oscillating masses along the x-axis or the y-axis, in order to generate Coriolis forces when the substrate is deflected, and

sensor elements for detecting deflections of said plurality of individual oscillating masses with respect to the substrate, said deflections being caused due to said generated Coriolis forces associated with the rotational movements around the x-axis or the y-axis,

wherein said plurality of individual oscillating masses are connected to at least one additional mass, which is not oscillating but is rotatable together with said plurality of individual oscillating masses on the substrate, around the at least one anchor, for the purpose of sensing the rotational movement around the z-axis, and

an additional sensor element is disposed to detect movement of said at least one additional mass.

2. A microgyroscope according to claim 1 wherein said sensor elements are arranged underneath said plurality of individual oscillating masses for detecting said deflections of the plurality of individual oscillating masses.

3. A microgyroscope according to claim 1, wherein the at least one additional mass surrounds the plurality of individual oscillating masses as a ring.

4. A microgyroscope according to claim 1, wherein the at least one additional mass is attached to the substrate with bending springs.

5. A microgyroscope according to claim 4, wherein the bending springs allow the at least one additional mass to rotate around the z-axis.

6. A microgyroscope according to claim 1, wherein the at least one anchor is centrally arranged.

7. A microgyroscope according to claim 1, wherein the plurality of individual oscillating masses are fastened to a central anchor.

8. A microgyroscope according to claim 7, wherein a central disk is arranged between the plurality of individual oscillating masses and the central anchor.

9. A microgyroscope according to claim 8, wherein the central disk is fastened to the central anchor as a universal joint to allow the plurality of individual oscillating masses to swing around the x-axis and the y-axis.

10. A microgyroscope according to claim 8, wherein the plurality of individual oscillating masses are fastened with springs to the central disk and/or the at least one additional mass.

11. A microgyroscope according to claim 8, wherein the plurality of individual oscillating masses and the at least one additional mass, and/or the central disk are pivoted around the z-axis.

12. A microgyroscope according to claim 1, wherein the plurality of individual oscillating masses are mutually connected to one another with synchronizing springs.

13. A microgyroscope according to claim 1, wherein the driving elements of the plurality of individual oscillating masses are fork-shaped electrodes.