Angular speed sensor and electronic apparatus

• US 8,230,740 B2
• Filed: 07/14/2009
• Issued: 07/31/2012
• Est. Priority Date: 07/29/2008
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Katsuki, Takashi, Nakazawa, Fumihiko, Inoue, Hiroaki
• Primary Examiner(s): Kwok, Helen C.
• Application Number:
  US12/502,499
• Publication Number:
  US 20100024547A1
• Time in Patent Office: 1,113 Days
• Field of Search: 735/041.2, 735/041.4, 735/041.5, 735/041.6, 735/040.4, 735/040.2
• 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

An angular speed sensor includes two oscillating portions arranged to oscillate in X-axis direction and Y-axis direction, where the oscillating portions are spaced from each other in X-axis direction. The sensor also includes two coupling beams capable of producing a standing wave oscillation, elongated in X-axis direction and spaced from each other in Y-axis direction, with the oscillating portions located therebetween. The coupling beams are connected to a supporting substrate via fixing posts. The coupling beams are bridged by first and second link portions, the first link portion being also connected to one of the oscillating portions and the second link portion to the other. The fixing posts are connected to the coupling beams at fixed points of the standing wave oscillation. The link portions include widened portions connected to the coupling beams at the fixed points of the standing wave oscillation.

Claims

1. An angular speed sensor, comprising:

a supporting substrate;

a first oscillating portion and a second oscillating portion arranged to oscillate in a first direction and in a second direction perpendicular to the first direction, the first and the second oscillating portions being spaced from each other in the first direction;

a pair of coupling beams extending in the first direction and spaced from each other in the second direction with the first and the second oscillating portions located therebetween, the coupling beams capable of producing standing wave oscillation;

a plurality of fixing posts fixing the coupling beams to the supporting substrate;

a first link portion serving as a bridge between the pair of coupling beams and connected to the first oscillating portion, the first link portion including two bridge beams spaced apart from each other in the first direction and each elongated in the second direction to be connected to the coupling beams, the two bridge beams being arranged to flank the first oscillating portion as a whole in the first direction; and

a second link portion serving as a bridge between the pair of coupling beams and connected to the second oscillating portion, the second link portion including two bridge beams spaced apart from each other in the first direction and each elongated in the second direction to be connected to the coupling beams, the two bridge beams of the second link portion being arranged to flank the second oscillating portion as a whole in the first direction;

wherein;

the fixing posts are connected to the coupling beams at fixed points of the standing wave oscillation; and

the bridge beams of the first and the second link portions each include a widened portion formed at an end thereof connected to the coupling beams, the widened portion being connected to the coupling beams at a fixed point of the standing wave oscillation of the coupling beams.

2. The angular speed sensor according to claim 1, further comprising a first driving unit and a second driving unit, the first driving unit being located opposite to the second oscillating portion with respect to the first oscillating portion and causing the first oscillating portion to vibrate in the first direction, the second driving unit being located opposite to the first oscillating portion with respect to the second oscillating portion and causing the second oscillating portion to vibrate in the first direction, wherein the first and the second driving unit are located between the pair of coupling beams, the first link portion includes a portion serving as a bridge between the pair of coupling beams on an opposite side of the first oscillating portion with respect to the first driving unit and connected to the first driving unit, and the second link portion includes a portion serving as a bridge between the pair of coupling beams on an opposite side of the second oscillating portion with respect to the second driving unit and connected to the second driving unit.

3. The angular speed sensor according to claim 1, wherein the fixing posts are connected to the coupling beams at all the fixed points of the standing wave oscillation.

4. The angular speed sensor according to claim 3, wherein the fixing posts are connected to the coupling beams at points dividing the coupling beams equally in five or nine segments in a longitudinal direction thereof.

5. An electronic apparatus comprising the angular speed sensor according to claim 1.

6. An angular speed sensor, comprising:

a supporting substrate;

a first oscillating portion and a second oscillating portion arranged to oscillate in a first direction and in a second direction perpendicular to the first direction, the first and the second oscillating portions being spaced from each other in the first direction;

a pair of coupling beams extending in the first direction and spaced from each other in the second direction with the first and the second oscillating portions located therebetween, the coupling beams capable of producing standing wave oscillation;

a plurality of fixing posts fixing the coupling beams to the supporting substrate;

a first link portion serving as a bridge between the pair of coupling beams and connected to the first oscillating portion, the first link portion including two bridge beams spaced apart from each other in the first direction and each elongated in the second direction to be connected to the coupling beams, the two bridge beams being arranged to flank the first oscillating portion as a whole in the first direction; and

a second link portion serving as a bridge between the pair of coupling beams and connected to the second oscillating portion, the second link portion including two bridge beams spaced apart from each other in the first direction and each elongated in the second direction to be connected to the coupling beams, the two bridge beams of the second link portion being arranged to flank the second oscillating portion as a whole in the first direction;

wherein;

the fixing posts are connected to the coupling beams at fixed points of the standing wave oscillation; and

the bridge beams of the first and the second link portions each include a branched portion formed at an end thereof connected to the coupling beams, the branched portion being connected to the coupling beams via at least two positions with a fixed point of the standing wave oscillation arranged therebetween.

7. The angular speed sensor according to claim 6, wherein each of the fixing posts is connected to the coupling beams so as to surround a fixed point of the coupling beams.

8. The angular speed sensor according to claim 6, further comprising a first driving unit and a second driving unit, the first driving unit being located opposite to the second oscillating portion with respect to the first oscillating portion and causing the first oscillating portion to vibrate in the first direction, the second driving unit being located opposite to the first oscillating portion with respect to the second oscillating portion and causing the second oscillating portion to vibrate in the first direction, wherein the first and the second driving unit are located between the pair of coupling beams, the first link portion includes a portion serving as a bridge between the pair of coupling beams on an opposite side of the first oscillating portion with respect to the first driving unit and connected to the first driving unit, and the second link portion includes a portion serving as a bridge between the pair of coupling beams on an opposite side of the second oscillating portion with respect to the second driving unit and connected to the second driving unit.

9. The angular speed sensor according to claim 6, wherein the fixing posts are connected to the coupling beams at all the fixed points of the standing wave oscillation of the coupling beams.

10. The angular speed sensor according to claim 9, wherein the fixing posts are connected to the coupling beams at points dividing the coupling beams equally in five or nine segments in a longitudinal direction thereof.

11. An electronic apparatus comprising the angular speed sensor according to claim 6.