IP Library Granted Patent US 7,454,971
Granted Patent B2
US 7,454,971 · App. 11/318,897 · Granted Nov 25, 2008

Oscillating micro-mechanical sensor of angular velocity

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Quick Facts
Patent No.
US 7,454,971
App. No.
11/318,897
Granted
Nov 25, 2008
Kind
B2
Abstract

The invention relates to measuring devices used in measuring angular velocity, and, more specifically, to oscillating micro-mechanical sensors of angular velocity. In the sensor of angular velocity according to the present invention seismic masses ( 1 ), ( 2 ), ( 36 ), ( 37 ) are connected to support areas by means of springs or by means of springs and stiff auxiliary structures, which give the masses ( 1 ), ( 2 ), ( 36 ), ( 37 ) a degree of freedom in relation to an axis of rotation perpendicular to the plane of the wafer formed by the masses, and in relation to at least one axis of rotation parallel to the plane of the wafer. The structure of the sensor of angular velocity according to the present invention enables reliable and efficient measuring particularly in compact oscillating micro-mechanical sensors of angular velocity.

Claims (36)

1. An oscillating micro-mechanical sensor of angular velocity, said sensor comprising:

two seismic masses which are attached to the body of a sensor component at support areas;

a connecting spring between the seismic masses, such that a primary motion of the sensor of angular velocity, which motion must be generated, is an opposite phase angular oscillation of the two seismic masses about the support areas; and

at least on bending spring which connects the seismic masses, said at least one bending spring mechanically synchronizes the primary motion of the seismic masses, and that the seismic masses are connected to the support areas by at least one of springs and stiff auxiliary structures, which give the seismic masses a degree of freedom in relation to an axis of rotation perpendicular to the plane of the disk formed by the seismic masses, and in relation to at least one axis of rotation in the direction of the plane of said disk.

2. Sensor of angular velocity according to claim 1 , wherein the sensor is a sensor of angular velocity as measured in relation to one axis, and the two seismic masses are attached to the body of the sensor component in at least two attachment spots.

3. Sensor of angular velocity according to claim 2 , wherein the bending spring is essentially higher than it is wide.

4. Sensor of angular velocity according to claim 2 , wherein the sensor of angular velocity comprises: rotary springs configured to perform a primary motion, which rotary springs have flexibility in relation to the primary motion direction, and torsion springs configured to perform a detection motion, which springs have flexibility in relation to a torsion oscillation caused by a torque moment generated by an external angular velocity.

5. Sensor of angular velocity according to claim 2 , wherein the oscillation caused by an external angular velocity is detected in a capacitive manner using electrodes located above or underneath the seismic masses.

6. Sensor of angular velocity according to claim 5 , wherein the electrodes are grown onto the inner surface of a wafer hermetically closing the sensor structure.

7. Sensor of angular velocity according to claim 2 , wherein the sensor of angular velocity further comprises:

a second bending spring extending essentially in the same direction as, and attached at the center point of, the second bening spring connecting the seismic masses of the sensor of angular velocity.

8. Sensor of angular velocity according to claim 2 , wherein the seismic masses are attached to the body of the sensor component at least two first attachment spots, and additionally attached by ef at least two second attachment spots, said at least two second attachments spots being installed at the center.

9. Sensor of angular velocity according to claim 2 , wherein the seismic masses are attached to the body of the sensor component by at least two first attachment spots, and additionally by at least to second attachment spots installed in the corners or at the edge.

10. Sensor of angular velocity according to claim 2 , wherein the seismic masses are attached to the body of the sensor component by at least two first attachment spots, which said attachment spots at one side are attached to the seismic masses by stiff auxiliary structures.

11. Sensor of angular velocity according to claim 2 , wherein the seismic masses are attached to the body of the sensor component by at least two attachment spots, which said attachment spots at one side are attached to the seismic masses by means of springs.

12. Sensor of angular velocity according to claim 2 , wherein the seismic masses are attached to the body of the sensor component by at least two first attachment spots, which are installed at the center of the ends, and additionally by at least two second attachment spots, which at one side, are attached to the seismic masses by spring.

13. Sensor of angular velocity according to claim 2 , wherein the sensor of angular velocity comprises:

strain relieving structures.

14. Sensor of angular velocity according to claim 2 , wherein the sensor of angular velocity comprises:

a comb structure.

15. Sensor of angular velocity according to claim 2 , wherein the sensor of angular velocity comprises:

radial comb structures.

16. Sensor of angular velocity according to claim 1 , wherein the sensor of angular velocity is a sensor of angular velocity measuring angular velocity in relation to two axes, the sensor containing two seismic masses attached to the body of the sensor component at two attachment spots.

17. Sensor of angular velocity according to claim 16 , wherein the bending spring is essentially higher than it is wide.

18. Sensor of angular velocity according to claim 16 , wherein the sensor of angular velocity comprises:

rotary springs configured to provide the primary motion of angular velocity, which said rotary springs have flexibility in relation to the primary motion of angular velocity;

first torsion springs configured to detect motion in a first direction, which said first torsion springs have flexibility in relation to the detection of motion in the first direction; and

second torsion springs configured to detect motion in a second direction, which said second springs have flexibility in relation to the detection of motion in the second direction.

19. Sensor of angular velocity according to claim 16 , wherein the oscillation caused by external angular velocity is detected in a capacitive manner by electrodes located above or underneath the seismic masses.

20. Sensor of angular velocity according to claim 19 , wherein the electrodes are grown onto the inner surface of a wafer hermetically closing the sensor structure.

21. Sensor of angular velocity according to claim 2 , wherein the attachment spots are joined in an anodic manner to the wafer hermetically closing the sensor structure.

22. Sensor of angular velocity according to claim 2 , wherein the attachment spots are joined to the wafer by a fusion joint hermetically closing the sensor structure.

23. An apparatus, comprising:

attaching means for attaching two seismic masses to the body of a sensor component at support areas;

spring connecting means for connecting a spring between the seismic masses, such that a primary motion of angular velocity, which motion must be generated, is an opposite phase angular oscillation of the two seismic masses about the support areas; and

bending spring connecting means for connecting a bending spring between the seismic masses, said at least one bending spring mechanically synchronizes the primary motion of the seismic masses, and that the seismic masses are connected to the support areas by at least one of springs and stiff auxiliary structures, which give the seismic masses a degree of freedom in relation to an axis of rotation perpendicular to the plane of the disk formed by the seismic masses, and in relation to at least one axis of rotation in the direction of the plane of said disk.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 5, 2021
From: MURATA ELECTRONICS OY
To: MURATA MANUFACTURING CO., LTD.
Reel/Frame 057705/0891 →
CHANGE OF NAME Recorded Oct 22, 2012
From: VTI TECHNOLOGIES OY
To: MURATA ELECTRONICS OY
Reel/Frame 029170/0012 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 29, 2006
From: BLOMQVIST, ANSSI
To: VTI TECHNOLOGIES OY
Reel/Frame 017732/0778 →