Other

Fujitsu Corporation

Fujitsu Media Devices Limited

Fujitsu Towa Electron Limited

Kazutsugu Kikuchi

Masanori Yachi

Hiroshi Ishikawa

Yoshio Satoh

Yoshitaka Takahashi

Kazuhiro Ohta

Keiji Saito

A tuning-fork vibration gyro including a ferroelectric tuning-fork vibration body generating a plurality of sensor signals and a sensor circuit to which the sensor signals generated by the tuning-fork vibration body are input. The sensor circuit includes a differential amplifier having two input terminals between which the sensor signals are input, and a capacitor being connected between the two input terminals of the differential amplifier.

Tuning fork vibration gyro

A tuning-fork type vibration gyro enables to suppress pyroelectric noise caused by temperature change and to obtain sensor output having high signal-to-noise ratio. The tuning-fork type vibration gyro includes a tuning-fork type vibration body having two arms mutually disposed in parallel and a base for commonly supporting one end of the each arm, wherein a longitudinal direction of the two arms is defined as a z-axis and a perpendicular direction thereto is defined as an x-axis; driving electrodes respectively formed on the two arms for generating vibration of the two arms in a direction parallel to the x-axis; detecting electrodes respectively formed on the two arms for detecting electromotive force generated when the tuning-fork type vibration body is rotated around the z-axis; and dummy electrodes formed on the two arms in respective areas different from the driving electrodes and the detecting electrodes.

Tuning-fork type vibration gyro and electrode trimming method therefor

A tuning fork type vibrator including two arms and a base is supported by a supporting substrate mounted on a stem, and an oscillation limiting member formed from a ring-shaped rubber-like elastic body is mounted with its one face secured to the stem so as to surround the base. When an external vibration or impact is applied, the tuning fork type vibrator oscillates in response to the vibration or impact, but the oscillation range of the tuning fork type vibrator is limited by the presence of this oscillation limiting member, and thus bumping of the tuning fork type vibrator against the surrounding members such as the stem is prevented. Moreover, a gyro characteristic is not impaired, and a loss of the gyro function due to a stop of drive vibration does not occur.

Tuning fork type vibration gyro

The shape of drive electrodes and/or the shape of detection electrodes of a tuning fork type vibration gyro are made asymmetrical between the inside and outside of the arm, and between the surface and reverse face of the arm, to reduce the abnormal vibration and leaking output. The drive electrodes to be provided on the inside parts of the surface and reverse face of the first arm are formed smaller than the drive electrodes to be provided on the outside parts of the surface and reverse face thereof. The length of the detection electrode to be provided on the outside lateral face of the second arm is formed short. The drive electrodes to be provided on the surface and reverse face of the first arm are extended to the base side from the boundary position between the first arm and the base, and the detection electrodes to be provided on the surface and reverse face of the second arm are extended to the base side from the boundary position between the second arm and the base.

In a tuning fork type vibration element provided in a tuning fork type vibration gyro, the sum of inertial moments of a base to an inertial moment of two arms is 1.0 or larger. The inertial moment of the two arms is obtained by multiplying the square of a rotation radius, which is a distance from a center axis of torsional vibration as a center position between the two arms to a center of gravity of the two arms with a mass of the two arms, and the inertial moment of the base is obtained by multiplying the square of the rotation radius from the center axis of the same torsional vibration.

Growing community of inventors

Nagano, Japan

Kazutsugu Kikuchi