Angular velocity sensor

• US 6,739,191 B2
• Filed: 12/14/2000
• Issued: 05/25/2004
• Est. Priority Date: 12/28/1999
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Moriya, Kazufumi, Mochida, Yoichi
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US09/737,183
• Publication Number:
  US 20010004847A1
• Time in Patent Office: 1,258 Days
• Field of Search: 735/041.2, 735/041.4, 735/040.4, 735/040.2, 735/041.3, 735/041.5
• US Class Current: 73/504.14
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis

Abstract

An angular velocity sensor includes a substrate; a first vibrator supported on the substrate by a first support beam, such as to be vibratable in a direction parallel to the substrate; a second vibrator supported by a second support beam parallel to the first vibrator, such as to be vibratable in a direction orthogonal to the vibrating direction of the first vibrator; a vibration generator for vibrating the first vibrator parallel to the substrate; an angular velocity detector for detecting the amount of displacement of the second vibrator due to an angular velocity; and a vibration-state monitor provided between the substrate and the first vibrator for monitoring the amount of displacement of the first vibrator when it is vibrated by the vibration detector.

Claims

1. An angular velocity sensor comprising:

a substrate;

a first vibrator supported on said substrate by a first support beam to be vibratable in a plane and in a first direction parallel to said substrate;

a second vibrator supported by a second support beam to be vibratable in a second direction orthogonal to a vibrating direction of said first vibrator and in the same plane thereof, said second vibrator being displaceable in said second direction orthogonal to the vibrating direction of said first vibrator when an angular velocity is applied thereto, said first vibrator being supported so as not to be substantially displaceable in said second direction;

a vibration generator supported on said substrate for vibrating said first vibrator parallel to said substrate;

an angular velocity detector supported on said substrate for detecting an amount of displacement of said second vibrator in said second direction when an angular velocity is applied thereto;

a vibration-state monitor provided between said substrate and said first vibrator for monitoring an amount of displacement of said first vibrator in said first direction, when said first vibrator is vibrated by said vibration generator, wherein said angular velocity detector, and said vibration-state monitor, each include respective fixed side and movable side electrodes, each of which extend in the first direction; and

a fixed component mounted on said substrate;

wherein

said fixed side electrode of said vibration-state monitor and said fixed side electrode of said angular velocity detector are integrally provided on said fixed component.

2. An angular velocity sensor according to claim 1, wherein the second vibrator is structured and arranged to be vibratable both in the first direction of vibration of the first vibrator and in the second direction orthogonal to the vibrating direction of the first vibrator.

3. An angular velocity sensor according to claim 1, wherein said first support beam is positioned between said substrate and said first vibrator and is structured and arranged to support said first vibrator so that said first vibrator is displaceable in one direction, and said second support beam is positioned between said first vibrator and said second vibrator and is structured and arranged to support said second vibrator so as to be displaceable in a direction orthogonal to said one direction.

4. An angular velocity sensor according to claim 1, wherein:

in said angular velocity detector, said fixed side electrode is a detection fixed side electrode and is provided on said substrate; and

said movable side electrode is a detection movable side and is provided on said second vibrator opposite to said detection fixed side electrode.

5. An angular velocity sensor according to claim 1, wherein:

in said vibration-state monitor said fixed side electrode is a monitor fixed side electrode and is provided on said substrate; and

said movable side electrode is a monitor movable side electrode and is provided on said first vibrator opposite to said monitor fixed side electrode.

6. An angular velocity sensor according to claim 5, wherein:

in said angular velocity detector, said fixed side electrode is a detection fixed side electrode and is provided on said substrate; and

said movable side electrode is a detection movable side electrode and is provided on said second vibrator opposite to said detection fixed side electrode.

7. An angular velocity sensor according to one of claims 4 and 6, wherein said detection fixed side electrode and said detection movable side electrode are structured and arranged such that an electrostatic capacitance therebetween varies in accordance with the displacement of said second vibrator.

8. An angular velocity sensor according to one of claims 5 and 6, wherein said monitoring fixed side electrode and said monitoring movable side electrode are structured and arranged such that an electrostatic capacitance therebetween varies in accordance with displacement of said first vibrator.