Angular velocity measuring device

• US 8,302,476 B2
• Filed: 09/15/2006
• Issued: 11/06/2012
• Est. Priority Date: 09/15/2006
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Matsumoto, Masahiro, Okada, Yasushi, Sonobe, Hisao
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US12/376,244
• Publication Number:
  US 20100095769A1
• Time in Patent Office: 2,244 Days
• Field of Search: 735/041.2, 735/041.4, 735/041.6
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5726 Signal processing
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames

Abstract

Disclosed herein is an angular velocity measuring device including: first and second oscillators elastically supported on a substrate; an elastic connecting beam elastically connecting the first and the second oscillator; and an oscillating means for oscillating the first and the second oscillator for differential oscillation, wherein a viscous force generating means for suppressing in-phase oscillation of the first and the second oscillator is incorporated into the elastic connecting beam.

Claims

1. An angular velocity measuring device comprising:

first and second oscillators elastically supported on a substrate;

an elastic connecting beam elastically connecting the first and the second oscillators;

an oscillating means for oscillating the first and second oscillators for differential oscillation by pulling the first and second oscillators in opposite driving directions;

wherein a viscous force generating means for producing viscous force against motions in said opposite driving directions to suppress in-phase oscillation of the first and second oscillators in said driving directions is incorporated into the elastic connecting beam.

2. The angular velocity measuring device according to claim 1, wherein the viscous force generating means includes first flat plates mechanically connected to the elastic connecting beam, and second flat plates mechanically connected to the substrate opposite to the first flat plates, respectively.

3. The angular velocity measuring device according to claim 2 further comprising a capacitance measuring means for measuring capacitance between the first flat plates mechanically connected to the elastic connecting beam and the second flat plates mechanically connected to the substrate.

4. The angular velocity measuring device according to claim 3 further comprising an electrostatic force generating means for exerting electrostatic force on the first and the second oscillator such that the capacitance measuring means provides a predetermined output.

5. The angular velocity measuring device according to claim 4 further comprising a cover disposed opposite to the substrate so as to cover the first and the second oscillators;

wherein a gap between the cover and the viscous force generating means is narrower than a gap between the cover, and the first and the second oscillator.

6. The angular velocity measuring device according to claim 4 further comprising an acceleration measuring means that provides a signal based on the capacitance between the first flat plates mechanically connected to the elastic connecting beam and the second flat plates mechanically connected to the substrate and indicating an acceleration in directions in which the first and the second oscillator oscillate.

7. The angular velocity measuring device according to claim 3 further comprising an acceleration measuring means that provides a signal based on the capacitance between the first flat plates mechanically connected to the elastic connecting beam and the second flat plates mechanically connected to the substrate and indicating an acceleration in directions in which the first and the second oscillator oscillate.

8. The angular velocity measuring device according to claim 3 further comprising a cover disposed opposite to the substrate so as to cover the first and the second oscillators;

wherein a gap between the cover and the viscous force generating means is narrower than a gap between the cover, and the first and the second oscillator.

9. The angular velocity measuring device according to claim 2 further comprising a cover disposed opposite to the substrate so as to cover the first and the second oscillators;

wherein a gap between the cover and the viscous force generating means is narrower than a gap between the cover, and the first and the second oscillator.

10. An angular velocity measuring device comprising:

first and second oscillators elastically supported on a substrate;

an elastic connecting beam elastically connecting the first and the second oscillator; and

an oscillating means for oscillating the first and the second oscillator for differential oscillation; and

a cover disposed opposite to the substrate so as to cover the first and the second oscillators;

wherein a viscous force generating means for suppressing in-phase oscillation of the first and the second oscillator is incorporated into the elastic connecting beam; and

wherein a gap between the cover and the viscous force generating means is narrower than a gap between the cover, and the first and the second oscillator.

11. The angular velocity measuring device according to claim 10 further comprising an acceleration measuring means that provides a signal based on the capacitance between the first flat plates mechanically connected to the elastic connecting beam and the second flat plates mechanically connected to the substrate and indicating an acceleration in directions in which the first and the second oscillator oscillate.