Angular velocity sensor device having oscillators
First Claim
Patent Images
1. An angular velocity sensor device comprising:
- a sensor element including a movable portion which is oscillated by driving on a specific plane, and receives a Coriolis force generated in a specific direction parallel to the specific plane when an angular velocity is generated around an angular velocity axis perpendicular to the specific plane, the sensor element being for outputting at least one output signal in accordance with the Coriolis force; and
a circuit portion electrically connected to the sensor element to receive the output signal from the sensor element, the circuit portion being for determining the angular velocity by a first signal caused by the Coriolis force and a second signal not caused by the Coriolis force, based on the output signal, the second signal being used as a reference.
1 Assignment
0 Petitions
Accused Products
Abstract
An angular velocity sensor device includes drive oscillators oscillated by driving in drive direction a0, and detecting oscillators connected to the drive oscillators and oscillated in detecting directions a1, a2 by a Coriolis force, which is generated by an angular velocity in a direction K. The directions a1, a2 respectively make an angle θ with the direction K. Detection electrodes are provided for the detecting oscillators, and produce output signals. A signal caused by an inertia force and a signal caused by the Coriolis force are obtained from the output signals, and the angular velocity is determined by the two signals.
-
Citations
34 Claims
-
1. An angular velocity sensor device comprising:
-
a sensor element including a movable portion which is oscillated by driving on a specific plane, and receives a Coriolis force generated in a specific direction parallel to the specific plane when an angular velocity is generated around an angular velocity axis perpendicular to the specific plane, the sensor element being for outputting at least one output signal in accordance with the Coriolis force; and
a circuit portion electrically connected to the sensor element to receive the output signal from the sensor element, the circuit portion being for determining the angular velocity by a first signal caused by the Coriolis force and a second signal not caused by the Coriolis force, based on the output signal, the second signal being used as a reference. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
the output signal is compound from the first signal and the second signal; and
the circuit portion divides the output signal into the first signal and the second signal.
-
-
3. The angular velocity sensor device of claim 1, wherein a phase of the first signal is shifted at 90°
- from a phase of the second signal.
-
4. The angular velocity sensor device of claim 1, wherein:
-
the movable portion is oscillated by driving in a first direction, and is oscillated by the Coriolis force in a second direction, the second direction defining an angle other than 90°
with the first direction; and
the second signal is caused by an inertia force applied to the movable portion in the first direction.
-
-
5. The angular velocity sensor device of claim 1, wherein the circuit portion calculates an intensity ratio between the first signal and the second signal to determine the angular velocity.
-
6. The angular velocity sensor device of claim 1, wherein:
-
the sensor element outputs first and second output signals; and
the circuit portion obtains the second signal by performing subtraction or addition of the first and second output signals.
-
-
7. The angular velocity sensor device of claim 1, wherein the second signal is caused by an inertia force applied to the movable portion.
-
8. The angular velocity sensor device of claim 1, wherein the movable portion includes:
-
an oscillator for being oscillated by driving in a drive direction and for being oscillated by the Coriolis force in a detecting direction non-parallel to the specific direction in which the Coriolis force is generated; and
a detecting portion for outputting the output signal to detect the Coriolis force applied to the oscillator.
-
-
9. The angular velocity sensor device of claim 1, wherein the movable portion includes:
-
a plurality of oscillators which is oscillated by driving with an approximately equal driving magnitude and is oscillated by the Coriolis force in a detecting direction non-parallel to the specific direction in which the Coriolis force is generated; and
a plurality of detecting portions each provided for a corresponding one of the plurality of oscillators.
-
-
10. The angular velocity sensor device of claim 1, wherein the movable portion includes:
-
a first oscillator which is oscillated by driving on the specific plane;
second and third oscillators which are oscillated by the Coriolis force in first and second detecting directions when the angular velocity is generated around the angular velocity axis, the first and second detecting directions respectively defining first and second angles larger than zero with the specific direction in which the Coriolis force is generated;
first and second beams connecting the first oscillator to the second oscillator and to the third oscillator; and
a detection portion for detecting the Coriolis force applied to the second and third oscillators.
-
-
11. The angular velocity sensor device of claim 10, wherein the first and second angles are different from each other.
-
12. The angular velocity sensor device of claim 10, further comprising:
-
a fixed portion to which the first oscillator is connected to be oscillated by driving in a drive direction; and
third and fourth beams connecting the first oscillator to the fixed portion at both sides of the first oscillator to oscillate the first oscillator by an elastic force thereof, the third and fourth beams being nonsymmetrical to each other.
-
-
13. The angular velocity sensor device of claim 10, wherein the first and second angles are defined by a processing error produced when the sensor device is manufactured.
-
14. The angular velocity sensor device of claim 10, wherein the first, second and third oscillators, and the detecting portion are oscillated by driving together.
-
15. The angular velocity sensor device of claim 10, wherein:
-
the first oscillator is oscillated by driving in a drive direction with a first resonance frequency; and
the second oscillator is oscillated by the Coriolis force in the detecting direction with a second resonance frequency approximately equal to the first resonance frequency.
-
-
16. The angular velocity sensor device of claim 1, further comprising;
-
a fixed portion to which the movable portion is connected to be oscillated by driving in a drive direction;
first and second beams connecting the movable portion to the fixed portion at both sides of the movable portion to oscillate the movable portion by an elastic force thereof, the first and second beams being nonsymmetrical to each other.
-
-
17. The angular velocity sensor device of claim 1, wherein the movable portion includes:
-
first and second drive oscillators which are oscillated by driving in first and second drive directions on the specific plane perpendicular to the angular velocity axis;
first and second detecting oscillators respectively connected to the first and second drive oscillators to be oscillated by the Coriolis force respectively in first and second detecting directions when the angular velocity is generated, the first and second detecting directions defining first and second angles with the specific direction in which the Coriolis force is generated, the first and second angles being larger than zero; and
first and second detecting portions respectively provided for the first and second detecting oscillators to detect the Coriolis force applied to the first and second detecting oscillators.
-
-
18. The angular velocity sensor device of claim 17, wherein the first and second detecting oscillators are respectively disposed inside the first and second drive oscillators, and are respectively connected to the first and second drive oscillators via first and second beams.
-
19. The angular velocity sensor device of claim 17, wherein the first and second drive oscillators are connected to each other via a beam.
-
20. The angular velocity sensor device of claim 17, wherein the first and second detecting oscillators are respectively disposed outside the first and second drive oscillators, and are respectively connected to the first and second drive oscillators via first and second beams.
-
21. The angular velocity sensor device of claim 17, wherein the first and second drive oscillators are independent of each other.
-
22. The angular velocity sensor device of claim 17, wherein the first and second angles are different from each other.
-
23. The angular velocity sensor device of claim 17, further comprising means for controlling driving amplitudes of the first and second drive oscillators to be approximately equal to each other.
-
24. The angular velocity sensor device of claim 17, further comprising monitoring means for monitoring first and second physical quantities of drive oscillations of the first and second drive oscillators.
-
25. The angular velocity sensor device of claim 17, further comprising means for controlling amplitudes of first and second output signals to be approximately equal to each other, the first and second output signals being outputted from the first and second detecting portions, respectively, in accordance with the Coriolis force.
-
26. The angular velocity sensor device of claim 25, further comprising control means for controlling driving amplitudes of the first and second drive oscillators constant based on the physical quantity monitored by the monitoring means.
-
27. The angular velocity sensor of claim 17, wherein the Coriolis force is applied to the first and second detecting oscillators directly to oscillate the first and second detecting oscillators.
-
28. The angular velocity sensor of claim 17, wherein the Coriolis force is applied to the first and second drive oscillators and is transmitted to the first and second detecting oscillators to oscillate the first and second detecting oscillators.
-
29. The angular velocity sensor of claim 1, wherein the circuit portion has means for extracting the first signal from the output signal by using the second signal.
-
30. An angular velocity sensor device comprising:
-
first and second detecting oscillators for detecting an angular velocity generated around an angular velocity axis, the first and second detecting oscillators being oscillated in first and second detecting directions, respectively, by a Coriolis force to output first and second output signals in accordance with the Coriolis force when the angular velocity is generated, the first and second detecting directions being non-parallel to a specific direction in which the Coriolis force is generated;
first signal calculating means for calculating a first signal, which is caused by the Coriolis force, from the first and second output signals;
second signal calculating means for calculating a second signal, which is not caused by the Coriolis force, from the first and second output signals; and
angular velocity calculating means for calculating the angular velocity based on the first and second signals calculated by the first signal calculating means and the second signal calculating means. - View Dependent Claims (31, 32)
the first signal is obtained by performing addition of the first and second output signals; and
the second signal is obtained by performing subtraction of the first and second signals.
-
-
33. An angular velocity sensor device comprising:
-
a first sensor element disposed on a first chip to output a first output signal in accordance with an angular velocity generated around an angular velocity axis;
a second sensor element disposed on a second chip to output a second output signal in accordance with the angular velocity, the second chip being independent of the first chip; and
means for calculating a first signal caused by a Coriolis force generated by the angular velocity and a second signal not caused by the Coriolis force, based on the first and second output signals, and for calculating the angular velocity based on the first and second signals. - View Dependent Claims (34)
-
Specification