Process of making an acceleration detecting element

• US 6,786,094 B2
• Filed: 05/01/2001
• Issued: 09/07/2004
• Est. Priority Date: 05/02/2000
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Shibahara, Teruhisa, Oguchi, Takahiro, Konaka, Yoshihiro
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US09/846,861
• Publication Number:
  US 20010037682A1
• Time in Patent Office: 1,225 Days
• Field of Search: 735/040.4, 735/040.2, 735/041.2, 735/041.3, 735/041.4, 735/041.5, 735/041.6, 735/143.2
• 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

A vibrator includes: a vibrating body; a driving unit for causing the vibrating body to vibrate in a predetermined vibrating direction; and a driving monitoring unit for detecting vibration displacement in a driving direction of the vibrating body. Stabilization of vibration in the driving direction of the vibrating body is achieved by applying positive feedback control to the driving unit based on the state of the vibration displacement in the driving direction of the vibrating body detected by this driving monitoring unit. The driving monitoring unit is constructed and arranged so as to be provided in a barycentric region of the vibrating body to detect the vibration displacement in the driving direction of the barycentric region of the vibrating body.

Claims

1. A vibrator comprising:

a vibrating body;

a driving unit for causing said vibrating body to vibrate in a predetermined vibrating direction; and

a driving monitoring unit provided in a barycentric region of said vibrating body for detecting vibration displacement in a driving direction of said vibrating body.

2. A vibrator according to claim 1, wherein said vibrating body vibrates in the driving direction thereof and in a Coriolis force direction that is substantially perpendicular to said driving direction when a Coriolis force is applied to said vibrating body, and further comprising a Coriolis force direction vibrating detecting unit for detecting vibration displacement in the Coriolis force direction of said vibrating body.

3. A vibrator according to claim 2, wherein said vibrating body has a double-frame construction obtained by connecting an inner frame to the inside of an outer frame via a coupling beam so that said vibrating body can flexibly vibrate in the Coriolis force direction, and said driving unit causes said outer frame and said inner frame to vibrate in an integral manner in the driving direction, said inner frame being constructed and arranged so as to be vibrated in the Coriolis force direction with respect to said outer frame due to the Coriolis force caused by an angular velocity, and said driving monitoring unit being provided in the barycentric region of said vibrating body disposed inside said inner frame while being supported by said inner frame.

4. A vibrator according to claim 3, in which said Coriolis force is caused by an angular velocity of rotation around an axis having a direction perpendicular to both said driving direction and said Coriolis direction and further comprising a circuit responsive to said Coriolis force direction vibrating detecting unit for determining said angular velocity of rotation.

5. A vibrator according to claim 1, the vibrator further includes a plurality of comb-shaped fixed electrodes;

and

the driving monitoring unit includes a plurality of comb-shaped movable electrodes disposed in the barycentric region of the vibrating body;

wherein

each of the plurality of comb-shaped movable electrodes and each of the plurality of comb-shaped fixed electrodes include a plurality of tines;

the plurality of tines of each of the plurality of comb-shaped movable electrodes extend only in one direction and the plurality of tines of each of the plurality of comb-shaped fixed electrodes extend only in a direction that is opposite to the one direction; and

the plurality of tines of each of the plurality of comb-shaped movable electrodes engage the plurality of tines of a corresponding one of the plurality of comb-shaped fixed electrodes such that the vibration displacement in the driving direction of the vibrating body is detected.