Title:
ANGULAR VELOCITY SENSOR
Document Type and Number:
WIPO Patent Application WO/1998/001722
Kind Code:
A1
Abstract:
A pivot (130) is disposed along a Z axis on a semiconductor substrate (100) the upper surface of which extends along an X-Y plane, and a rotor (200) made of a dielectric material is engaged with the pivot. The rotor is supported by the pivot so that it can tilt and rotate freely. The rotor includes weights (211, 212) on its peripheries, and stators (111, 115) made of a conductive material are disposed round the weights. When an A.C. voltage having a predetermined frequency is applied to the stators, the rotor rotates while floating on the basis of the principle of an induction motor. When the substrate (100) has an angular velocity $g(v)x round the X axis, a Coriolis force Fcz in the positive direction of the Z axis acts on the weight (211) passing through the X axis with a velocity component in the positive direction of the Y axis, and thus the weight moves away from the substrate. On the other hand, a Coriolis force -Fcz in the negative direction of the Z axis acts on the weight (212) passing through the X axis with the velocity component in the negative direction of the Y axis, and thus weight approaches the substrate. Fixed electrodes (141AB, 142AB) on the substrate and moving electrodes (231, 232) on the rotor cooperate to form capacitors C1, C2, and the magnitude of the Coriolis force is detected by determining the difference in capacitance of both capacitors. The magnitude of the Coriolis force so detected is outputted as a value of an angular velocity $g(v)x round the X axis. Even in the presence of acceleration, the acceleration component can be cancelled by determining the difference.
Inventors:
OKADA KAZUHIRO (JP)
Application Number:
PCT/JP1996/001926
Publication Date:
January 15, 1998
Filing Date:
July 10, 1996
Export Citation:
Assignee:
WAKO KK (JP)
OKADA KAZUHIRO (JP)
OKADA KAZUHIRO (JP)
International Classes:
G01C19/56; G01C19/5712; G01P3/16; (IPC1-7): G01C19/56; G01P9/04
Foreign References:
| JPS58221109A | 1983-12-22 | |||
| JPH06510604A | 1994-11-24 | |||
| JPH04178517A | 1992-06-25 | |||
| US3842681A | 1974-10-22 | |||
| JPS6117910A | 1986-01-25 | |||
| JPH0791958A | 1995-04-07 | |||
| JPH05248875A | 1993-09-28 | |||
| JPS63183508U | 1988-11-25 | |||
| JPS52109963A | 1977-09-14 | |||
| JPS61193018A | 1986-08-27 | |||
| JPS6397859U | 1988-06-24 |
Other References:
See also references of EP 0851212A4
Attorney, Agent or Firm:
Shimura, Hiroshi (6-1 Minamikamata 2-chom, Ohta-ku Tokyo 144, JP)
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