Detector for detecting angular velocities about perpendicular axes
First Claim
1. A detector for detecting at least one physical quantity from among linear acceleration, angular acceleration, and angular velocity, fabricated through micro-machining, comprising:
- a substrate;
a plurality of excitation beams extending along two different directions parallel to the surface of said substrate;
a fixing portion for fixing said excitation beams to said substrate at an intersecting portion of said excitation beams;
a plurality of mass portions each having an inertial mass and supported at free ends of said excitation beams to be excited with respect to said substrate;
a plurality of excitation electrodes for exciting said mass portions by providing electrical force, each excitation electrode being disposed to face said corresponding mass portion at one end of said mass portion; and
a driving means for applying AC voltage to said excitation electrodes;
and wherein said mass portions are excited such that two adjacent mass portions vibrate parallel to said substrate and in opposite phases in a rotational direction about a vertical axis to said surface of said substrate, and said excitation beams have flexibility in both planes which are parallel and perpendicular to the surface of said substrate.
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Accused Products
Abstract
A detector has first and second excitation beams extending along X-axis and Y-axis directions. These beams are fixed to a substrate via an intersecting portion. Mass portions are disposed at free ends of the beams. Sensing electrodes are disposed at the central portions of the mass portions to face the mass portions. By electrostatic force generated between the excitation electrodes and the mass portions, two mass portions vibrate in the Y-axis direction, while the remaining two mass portions vibrate in the X-axis direction. When an angular velocity Ωx acts about the X axis, Z-axis Coriolis forces F1a and F1b act on the mass portions that are vibrating in the Y-axis direction. When an angular velocity Ωy acts about the Y axis, Z-axis Coriolis forces F2a and F2b act on the mass portions that are vibrating in the X-axis direction. These vibrations are detected by the sensing electrodes in order to detect the angular velocities Ωx and Ωy.
109 Citations
22 Claims
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1. A detector for detecting at least one physical quantity from among linear acceleration, angular acceleration, and angular velocity, fabricated through micro-machining, comprising:
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a substrate; a plurality of excitation beams extending along two different directions parallel to the surface of said substrate; a fixing portion for fixing said excitation beams to said substrate at an intersecting portion of said excitation beams; a plurality of mass portions each having an inertial mass and supported at free ends of said excitation beams to be excited with respect to said substrate; a plurality of excitation electrodes for exciting said mass portions by providing electrical force, each excitation electrode being disposed to face said corresponding mass portion at one end of said mass portion; and a driving means for applying AC voltage to said excitation electrodes; and wherein said mass portions are excited such that two adjacent mass portions vibrate parallel to said substrate and in opposite phases in a rotational direction about a vertical axis to said surface of said substrate, and said excitation beams have flexibility in both planes which are parallel and perpendicular to the surface of said substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A detector for detecting at least one physical quantity from among angular velocity and linear acceleration, fabricated through micro-machining and comprising:
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a substrate; a plurality of excitation beams extending along two different directions parallel to the surface of said substrate; a fixing portion for fixing said excitation beams to said substrate at an intersecting portion of said excitation beams; four mass portions each having an inertial mass, having an arcuate shape to together forming a ring-like shape, and being supported at free ends of said excitation beams to be excited with respect to said substrate; a plurality of excitation electrodes for exciting said mass portions in a rotational direction about a vertical axis to said substrate by providing electrical force, each excitation electrode being commonly disposed between two adjacent mass portions, two excitation electrodes being disposed at radially opposite positions with respect to said vertical axis; a plurality of excitation detection electrodes for detecting amplitude of vibration of said mass portions in said rotational direction, each excitation detection electrode being commonly disposed between two adjacent mass portions, two excitation detection electrodes being disposed at radially opposite positions with respect to said vertical axis and between said two excitation electrodes; a plurality of sensing electrodes for detecting a physical quantity in relation to a Coriolis force generated in a direction parallel to said vertical axis at each mass portion, or in relation to an acceleration force, each sensing electrode being disposed to face said mass portions; and a driving means for applying AC voltage to said excitation electrodes; and wherein said mass portions are excited such that two adjacent mass portions vibrate parallel to said substrate and in opposite phases in said rotational direction about said vertical axis, and said excitation beams have flexibility in both planes which are parallel and perpendicular to the surface of the substrate. - View Dependent Claims (18, 19, 20, 21, 22)
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Specification