Multi-axial angular velocity sensor
First Claim
1. An angular velocity sensor for detecting an angular velocity component about a Z-axis in an XYZ three-dimensional coordinate system, said sensor comprising:
- an oscillator made of a substrate with an enough thickness to obtain a mass sufficient to provide the sensor with a required sensitivity;
a sensor casing for accommodating the oscillator therewithin;
a flexible member for connecting the oscillator to the sensor casing so that the oscillator can be moved with respect to the sensor casing;
a driving device for oscillating the oscillator in an X-axis direction in said coordinate system; and
a detection device for detecting a deviation of the oscillator in a Y-axis direction in said coordinate system;
wherein a detection value of said detection device is output as a value indicating an angular velocity component about the Z-axis.
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Accused Products
Abstract
A flexible substrate (110) having flexibility and a fixed substrate (120) disposed so as to oppose it are supported at their peripheral portions by a sensor casing (140). An oscillator (130) is fixed on the lower surface of the flexible substrate. Five lower electrode layers (F1 to F5: F1 and F2 are disposed at front and back of F5) are formed on the upper surface of the flexible substrate. Five upper electrode layers (E1 to E5) are formed on the lower surface of the fixed substrate so as to oppose the lower electrodes. In the case of detecting an angular velocity ωx about the X-axis, an a.c. voltage is applied across a predetermined pair of opposite electrode layers (E5, F5) to allow the oscillator to undergo oscillation Uz in the Z-axis direction. Thus, a Coriolis force Fy proportional to the angular velocity ωx is applied to the oscillator in the Y-axis. By this Coriolis force Fy, the oscillator is caused to undergo displacement in the Y-axis direction. As a result, the distance between opposite electrode layers (E3, F3) arranged in the positive direction of the Y-axis becomes smaller, and the distance between opposite electrode layers (E4, F4) arranged in the negative direction of the Y-axis becomes greater. Thus, capacitance value C3 increases and capacitance value C4 decreases. By change of the capacitance value, it is possible to detect the magnitude of the Coriolis force Fy, and to determine angular velocity ωx. Similarly, it is possible to detect an angular velocity ωy about the Y-axis and an angular velocity ωz about the Z-axis.
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Citations
7 Claims
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1. An angular velocity sensor for detecting an angular velocity component about a Z-axis in an XYZ three-dimensional coordinate system, said sensor comprising:
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an oscillator made of a substrate with an enough thickness to obtain a mass sufficient to provide the sensor with a required sensitivity;
a sensor casing for accommodating the oscillator therewithin;
a flexible member for connecting the oscillator to the sensor casing so that the oscillator can be moved with respect to the sensor casing;
a driving device for oscillating the oscillator in an X-axis direction in said coordinate system; and
a detection device for detecting a deviation of the oscillator in a Y-axis direction in said coordinate system;
wherein a detection value of said detection device is output as a value indicating an angular velocity component about the Z-axis. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification