SENSOR FOR DETECTING ACCELERATION AND ANGULAR VELOCITY

• US 20100300203A1
• Filed: 05/18/2010
• Published: 12/02/2010
• Est. Priority Date: 05/26/2009
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: GOTOH, Keisuke
• Granted Patent: US 8,567,248 B2
• Time in Patent Office: Days
• US Class Current: 73/504.15
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/14 by making use of gyroscopes gyroscopes per se G01C19/00
• CPC Class Codes: G01P 3/44 for measuring angular speed G01P3/56 takes precedence

Abstract

A sensor includes an acceleration detector, an angular velocity detector, a driver, and first to fourth springs. Each detector includes a pair of fixed electrodes, a pair of movable electrodes, and a pair of supporting members for supporting the movable electrodes. The driver causes the supporting members to vibrate in opposite phases in a first direction. The first spring couples the supporting members of the acceleration detector and has elasticity in a second direction perpendicular to the first direction. The second spring couples the supporting members of the acceleration detector to a base and has elasticity in both directions. The third spring couples the supporting members of the acceleration detector to the supporting members of the angular velocity detector and has elasticity in both directions. The fourth spring couples the supporting members to the movable electrodes of the angular velocity detector and has elasticity in the second direction.

Claims

1. A sensor for detecting acceleration and angular velocity, the sensor comprising:

a base;

an acceleration detector including a pair of first fixed electrodes, a pair of first movable electrodes, a pair of weights, and a pair of first supporting members configured to support the pair of first movable electrodes and joined to the pair of weights;

an angular velocity detector including a pair of second fixed electrodes, a pair of second movable electrodes, and a pair of second supporting members configured to support the pair of second movable electrodes;

a driver configured to cause the pair of first supporting members to vibrate in opposite phases in a first direction and configured to cause the pair of second supporting members to vibrate in opposite phases in the first direction;

a first spring configured to couple the pair of first supporting members together, the first spring having elasticity in a second direction perpendicular to the first direction;

a second spring configured to couple the pair of first supporting members to the base, the second spring having elasticity in both the first direction and the second direction;

a third spring configured to couple the pair of first supporting members to the pair of second supporting members, the third, spring having elasticity in both the first direction and the second direction; and

a fourth spring configured to couple the pair of second supporting members to the pair of second movable electrodes, the fourth spring having elasticity in the second direction.

2. The sensor according to claim 1, wherein

the acceleration is detected based on a change in a capacitance of a first capacitor due to inertial force, the first capacitor formed with the pair of first fixed electrodes and the pair of first movable electrodes, and

the angular velocity is detected based on a change in a capacitance of a second capacitor due to inertial force, the second capacitor formed with the pair of second fixed electrodes and the pair of second movable electrodes.

3. The sensor according to claim 1, wherein

each of the pair of first fixed electrodes and the pair of first movable electrodes has a comb-shape.

4. The sensor according to claim 1, wherein

each of the pair of second fixed electrodes and the pair of second movable electrodes has a comb-shape.

5. The sensor according to claim 1, wherein

the driver uses electrostatic force to cause the pair of first supporting members to vibrate in opposite phases in the first direction and to cause the pair of second supporting members to vibrate in opposite phases in the first direction.

6. The sensor according to claim 5, wherein

the driver includes a comb electrode.

7. The sensor according to claim 1, wherein

the driver uses electromagnetic force to cause the pair of first supporting members to vibrate in opposite phases in the first direction and to cause the pair of second supporting members to vibrate in opposite phases in the first direction.

8. The sensor according to claim 1, wherein

the base is a semiconductor substrate, and

the acceleration detector, the angular velocity detector, and the driver are integrated on the semiconductor substrate.

9. The sensor according to claim 1 wherein

the pair of first supporting members has a rectangular C-shape.

10. The sensor according to claim 1, wherein

the pair of second supporting members has a frame-shape.

11. A sensor for detecting acceleration and angular velocity, the sensor comprising:

a base;

an acceleration detector including a pair of first fixed electrodes a pair of first movable electrodes, a pair of weights, and a pair of first supporting members configured to support the pair of first movable electrodes and joined to the pair of weights;

an angular velocity detector including a pair of second fixed electrodes, a pair of second movable electrodes, and a pair of second supporting members configured to support the pair of second movable electrodes;

a driver configured to cause the pair of first supporting members to vibrate in opposite phases in a first direction and configured to cause the pair of second supporting members to vibrate in opposite phases in the first direction;

a first spring configured to couple the pair of first supporting members together, the first spring having elasticity in the first direction;

a second spring configured to couple the pair of first supporting members to the base, the second spring having elasticity in both the first direction and a second direction perpendicular to the first direction;

a third spring configured to couple the pair of first supporting members to the pair of second supporting members, the third spring having elasticity in both the first direction and the second direction;

a fourth spring configured to couple the pair of second supporting members to the pair of second movable electrodes, the fourth spring having elasticity in the second direction; and

a fifth spring configured to couple the pair of second supporting members together, the fifth spring having elasticity in the first direction.

12. The sensor according to claim 11, wherein

the acceleration is detected based on a change in a capacitance of a first capacitor due to inertial force, the first capacitor formed with the pair of first fixed electrodes and the pair of first movable electrodes, and

the angular velocity is detected based on a change in a capacitance of a second capacitor due to inertial force, the second capacitor formed with the pair of second fixed electrodes and the pair of second movable electrodes.

13. The sensor according to claim 11, wherein

each of the pair of first fixed electrodes and the pair of first movable electrodes has a comb-shape.

14. The sensor according to claim 11, wherein

each of the pair of second fixed electrodes and the pair of second movable electrodes has a comb-shape.

15. The sensor according to claim 11, wherein

the driver uses electrostatic force to cause the pair of first supporting members to vibrate in opposite phases in the first direction and to cause the pair of second supporting members to vibrate in opposite phases in the first direction.

16. The sensor according to claim 15, wherein

the driver includes a comb electrode.

17. The sensor according to claim 11, wherein

the driver uses electromagnetic force to cause the pair of first supporting members to vibrate in opposite phases in the first direction and to cause the pair of second supporting members to vibrate in opposite phases in the first direction.

18. The sensor according to claim 11, wherein

the base is a semiconductor substrate, and

the acceleration detector, the angular velocity detector, and the driver are integrated on the semiconductor substrate.

19. The sensor according to claim 11, wherein

the pair of first supporting members has a rectangular C-shape.

20. The sensor according to claim 11, wherein

the pair of second supporting members has a frame-shape.