Angular Velocity Measuring Device

• US 20100095769A1
• Filed: 09/15/2006
• Published: 04/22/2010
• Est. Priority Date: 09/15/2006
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Okada, Yasushi, Sonobe, Hisao, Matsumoto, Masahiro
• Granted Patent: US 8,302,476 B2
• Time in Patent Office: Days
• 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 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.

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 1 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 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.

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. 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.

11. 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.

12. 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.

13. The angular velocity measuring device according to claim 5 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. 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

first and second electrostatic generating means for exerting electrostatic force on the first and the second oscillator to oscillate the first and the second oscillator for differential oscillation;

wherein the first oscillator is connected mechanically to the first electrostatic force generating means by a first connecting beam such that the first oscillator has a rigidity with respect to oscillating directions higher than a rigidity with respect to directions parallel to the substrate in which the first oscillator oscillates,

the second oscillator is connected mechanically to the second electrostatic force generating means by a second connecting beam such that the second oscillator has a rigidity with respect to oscillating directions higher than a rigidity with respect to directions parallel to the substrate in which the second oscillator oscillates, and

the first connecting beam, the second connecting beam, a center of gravity of the first oscillator, and a center of gravity of the second oscillator are aligned.

8. The angular velocity measuring device according to claim 7, 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.