Matsushita Electric Industrial Co., Ltd.

Satoshi Ouchi

Masakazu Hatanaka

Toshiyuki Nozoe

Hirofumi Tajika

Koji Nomura

Junichi Yukawa

Shusaku Kawasaki

Katsunori Matsubara

Tsutomu Nakanishi

Michihiko Hayashi

An angular velocity sensor includes a tuning-fork-shaped substrate (), drivers () that are provided on the arms forming a tuning fork and vibrate the arms; monitors () for detecting vibrations generated by the drivers (); and detectors () for detecting displacement of vibrations made in application of an angular velocity. The drivers (), the monitors (), and the detectors () are made of a lower electrode layer, a piezoelectric thin film, and an upper electrode layer formed on the arms. The outer peripheral edge of the piezoelectric thin film is shaped like a step having at least one flat portion. The flat portion along the outer peripheral edge has no upper electrode layer formed thereon. This structure prevents short circuits between the lower electrode layer and the upper electrode layer.

Angular-velocity sensor

A thin film micromechanical resonator (resonator) having improved drive efficiency, a resonator gyro having improved sensitivity in detecting an angular velocity, and a navigation system and an automobile using the resonator gyro. The resonator includes a tuning fork structure made of a non-piezoelectric material, and a first electrode and a second electrode disposed respectively at the inner side and the outer side of the tuning fork arm. On the first and second electrodes, a first piezo film and a second piezo film are provided respectively, and a third electrode and a fourth are respectively provided electrode thereon. When an alternating voltage is applied to the third and fourth electrodes at the opposite phases each other, the tuning fork resonates in the direction perpendicular to the center line. The resonator gyro detects, at the sensing section which is formed of another electrodes and another piezo film, the Coriolis force generated in proportion to angular velocity given to the resonator.

Thin-film micromechanical resonator, thin-film micromechanical resonator gyro, and navigation system and automobile using the resonator gyro

An angular velocity sensor with improved detection chacteristics using a tuning fork vibrator made of a single crystalline piezoelectric material such as quartz. The turning fork vibrator includes two vibrators bonded together to provide an integral structure so that the vibrators by their respective crystal axis directions generate a piezoelectric phenomena in inverse polarities in their width directions. The tuning fork vibrator has two tuning fork arms and a tuning fork base. Two detection electrodes are respectively disposed on outer faces of the two tuning fork arms. And two other detection electrodes are respectively disposed on inner faces of the two tuning fork arms. Two drive electrodes are respectively disposed on the two tunings fork arms. The two detection electrodes disposed on the outer faces of the two tuning fork arms are commonly connected, and the two detection electrodes disposed on the inner faces of the two tuning fork arms are commonly connected for canceling capacitive coupling from drive section to detecting section.

Angular velocity sensor

The present invention aims at improving detection sensitivity of an angular rate sensor that uses a tuning fork vibrator composed of mono-quartz piezoelectric material such as crystallized quartz. To achieve this purpose, the present invention includes a tuning fork vibrator ( ) having two tuning fork prongs ( ) and ( ), and a tuning fork base ( ), comprised of two vibrators ( ) and ( ) directly bonded into one piece in an orientation of their thickness in a manner that they are oriented in a direction of crystallographic axis that produces piezoelectric phenomenon of reversed polarity with respect to each other in a lateral direction. There are electrodes ( ), ( ), ( ) and ( ) for detection, disposed to interior-side surfaces and exterior-side surfaces of both of the tuning fork prongs ( ) and ( ), and electrodes ( ) and ( ) for driving, disposed to both of the tuning fork prongs ( ) and ( ) in a such relation to the electrodes ( ), ( ), ( ) and ( ) for detection as to cancel capacitive couplings from the driving side to the detection side.

Angular speed sensor

An object of the present invention is to improve the efficiency of a driving operation of an angular rate sensor employing a tuning fork oscillator made of single crystalline piezoelectric material such as quartz. In order to achieve the object of the present invention, a tuning fork oscillator assembled directly has driver electrodes and detector electrodes provided on a first main surface, a second main surface, an outer surface, and an inner surface of a arm, respectively. The oscillator also has a driver electrode, a monitor electrode, and detector electrodes provided on a first main surface, a second main surface, an inner surface, and an outer surface of the other arm thereof, respectively. A driving voltage is supplied from a driving power source so that the two driver electrodes may be equal in the polarity while the polarity of the driver electrode is opposite to that of the driver electrodes.

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Hyogo, Japan

Satoshi Ouchi