Angular velocity sensor

• US 20070022827A1
• Filed: 07/25/2006
• Published: 02/01/2007
• Est. Priority Date: 07/28/2005
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited, Fujitsu Media Devices Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Limited, Fujitsu Media Devices Limited (Fujitsu Limited)
• Inventors: Takahashi, Yuji, Katsuki, Takashi, Ishikawa, Hiroshi, Sano, Satoshi, Nakazawa, Fumihiko, Yamaji, Takayuki
• Application Number:
  US11/492,090
• Publication Number:
  US 20070022827A1
• Time in Patent Office: Days
• US Class Current: 73/862.120
• 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 first gimbal portion, a second gimbal portion connected to the first gimbal portion by first torsion bars provided at opposing sides of the first gimbal portion, a frame portion connected to the second gimbal portion by second torsion bars provided at the opposing sides of the second gimbal portion, first electrostatic coupling portions provided at the opposing sides of the first gimbal portion to electrostatically couple the first gimbal portion and the second gimbal portion, and second electrostatic coupling portions provided at the opposing sides of the second gimbal portion to electrostatically couple the second gimbal portion and the frame portion. In the first gimbal portion, a maximum width of sides of a direction of the first torsion bars is greater than that of the sides where the first torsion bars are provided.

Claims

1. An angular velocity sensor comprising:

a first gimbal portion;

a second gimbal portion connected to the first gimbal portion by first torsion bars provided at opposing sides of the first gimbal portion;

a frame portion connected to the second gimbal portion by second torsion bars provided at the opposing sides of the second gimbal portion;

first electrostatic coupling portions provided at the opposing sides of the first gimbal portion to electrostatically couple the first gimbal portion and the second gimbal portion; and

second electrostatic coupling portions provided at the opposing sides of the second gimbal portion to electrostatically couple the second gimbal portion and the frame portion,

wherein in the first gimbal portion, a maximum width of sides of a direction of the first torsion bars is greater than that of the sides where the first torsion bars are provided.

3. The angular velocity sensor as claimed in claim 1, wherein in the first electrostatic coupling portion, a width of the sides of the direction of the first torsion bars is greater than that of the sides where the first torsion bars are provided.

5. The angular velocity sensor as claimed in claim 1, wherein one of the first electrostatic coupling portion and the second electrostatic coupling portion that respectively drive the first gimbal portion and the second gimbal portion is composed of comb-teeth electrodes.

6. The angular velocity sensor as claimed in claim 1, wherein the first electrostatic coupling portion and the second electrostatic coupling portion are composed of either comb-teeth electrodes or parallel plane plate electrodes.

7. The angular velocity sensor as claimed in claim 1, wherein:

at least one of the first electrostatic coupling portion and the second electrostatic coupling portion includes correction electrodes; and

the correction electrodes performs at least one of monitoring a change in electrostatic capacitance of the first gimbal portion or the second gimbal portion respectively and correcting an unbalanced drive of the first gimbal portion or the second gimbal portion respectively.

8. The angular velocity sensor as claimed in claim 7, wherein the correction electrodes are either electrodes of a comb-teeth structure or the electrodes of a parallel plane plate structure.

9. The angular velocity sensor as claimed in claim 1, wherein:

the first gimbal portion, the second gimbal portion, and the frame portion include a base semiconductor layer, an insulation layer, and an upper semiconductor layer; and

one of the first torsion bars and the second torsion bars have a thickness substantially identical to that of the upper semiconductor layer.

10. The angular velocity sensor as claimed in claim 5, wherein:

the first gimbal portion, the second gimbal portion, and the frame portion respectively include a base semiconductor layer, an insulation layer, and an upper semiconductor layer; and

the comb-teeth electrodes are composed of the upper semiconductor layer.

16. The angular velocity sensor as claimed in claim 1, wherein in the second gimbal portion, the maximum width of the sides of the direction of the second torsion bars is greater than that of the sides where the second torsion bars are provided.

2. An angular velocity sensor comprising:

a first gimbal portion;

a second gimbal portion connected to the first gimbal portion by first torsion bars provided at opposing sides of the first gimbal portion;

a frame portion connected to the second gimbal portion by second torsion bars provided at the opposing sides of the second gimbal portion;

a first electrostatic coupling portion provided at the opposing sides of the first gimbal portion to electrostatically couple the first gimbal portion and the second gimbal portion; and

a second electrostatic coupling portion provided at the opposing sides of the second gimbal portion to electrostatically couple the second gimbal portion and the frame portion,

wherein in the second gimbal portion, a maximum width of sides of a direction of the second torsion bars is greater than that of the sides where the second torsion bars are provided.

4. The angular velocity sensor as claimed in claim 2, wherein in the second electrostatic coupling portion, a width of the sides of the direction of the second torsion bars is greater than that of the sides where the second torsion bars are provided.

11. The angular velocity sensor as claimed in claim 2, wherein one of the first electrostatic coupling portion and the second electrostatic coupling portion that respectively drive the first gimbal portion and the second gimbal portion is composed of comb-teeth electrodes.

12. The angular velocity sensor as claimed in claim 2, wherein the first electrostatic coupling portion and the second electrostatic coupling portion are composed of either comb-teeth electrodes or parallel plane plate electrodes.

13. The angular velocity sensor as claimed in claim 2, wherein:

at least one of the first electrostatic coupling portion and the second electrostatic coupling portion includes correction electrodes; and

the correction electrodes performs at least one of monitoring a change in electrostatic capacitance of the first gimbal portion or the second gimbal portion respectively and correcting an unbalanced drive of the first gimbal portion or the second gimbal portion respectively.

14. The angular velocity sensor as claimed in claim 13, wherein the correction electrodes are either electrodes of a comb-teeth structure or the electrodes of a parallel plane plate structure.

15. The angular velocity sensor as claimed in claim 2, wherein:

the first gimbal portion, the second gimbal portion, and the frame portion include a base semiconductor layer, an insulation layer, and an upper semiconductor layer; and

one of the first torsion bars and the second torsion bars have a thickness substantially identical to that of the upper semiconductor layer.