The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 04, 2013
Filed:
Nov. 24, 2009
Hiroshi Iwasawa, Hitachinaka, JP;
Toshiaki Nakamura, Hitachinaka, JP;
Masahiro Matsumoto, Hitachi, JP;
Hiroshi Iwasawa, Hitachinaka, JP;
Toshiaki Nakamura, Hitachinaka, JP;
Masahiro Matsumoto, Hitachi, JP;
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, JP;
Abstract
The present invention aims to provide an angular velocity detection device which is capable of reducing the effect of coupling between a drive electrode and a first displacement detection electrode by a floating capacity, and is low in cost. In the angular velocity detection device, an oscillating bodyis displaceable in a first direction and a second direction which orthogonally intersect each other. The oscillating bodyis oscillated in the first direction by an electrostatic force corresponding to a drive signal generated by a non-interference signal generator. A carrier signal generated by the non-interference signal generatoris applied to the oscillating body. A first displacement detection circuitand a second displacement detection circuiteach detect a displacement of the oscillating bodyas a displacement modulation signal indicative of a change in electrostatic capacity synchronized with the carrier signal to thereby detect an angular velocity. Here, the frequency of the drive signal and the frequency of the carrier signal are set so as to be generated at such a frequency ratio that a higher harmonic of the drive signal multiplied by an odd number does not the displacement modulation signal.