Murata Manufacturing Co., Ltd.

Hideaki Sugibayashi

Keiichi Okano

A pressure sensor device includes an electrically insulative substrate, a base electrode layer, spacer portions, a guard electrode layer, and a membrane plate. A sensing electrode portion and monitoring electrode portions are located on the membrane plate and face the substrate. In a case where the monitoring electrodes are mounted on a circuit board, the monitoring electrodes detect at least one of stress or strain occurring in or on the spacer portions.

Pressure sensor device, pressure sensor module, and signal correction method for pressure sensor module

A vibrating gyroscope includes two input buffers each arranged to input voltage signals appearing at respective detection electrodes of one of two piezoelectric vibrators. An adding circuit adds up output voltages of the respective input buffers. An amplitude control circuit automatically controls a loop gain such that an output voltage of the adding circuit has a substantially constant amplitude. A phase-shift circuit controls the phase of a drive voltage supplied to the piezoelectric vibrators such that the piezoelectric vibrators oscillate by positive feedback. Two differential amplifier circuits each amplify a voltage difference corresponding to an angular velocity about an axis. Two synchronous detection circuits each perform detection using a synchronizing signal generated from an oscillation signal, and detect a voltage signal corresponding to the angular velocity.

Vibrating gyroscope

A piezoelectric vibrator of a vibration gyro vibrates in response to a drive voltage Vinput into a drive electrode, and when deformed by a Coriolis force, generates detection voltages V, between which a potential difference corresponds to the deformation, at detection electrodes. An AGC circuit outputs a drive voltage Vwhile performing automatic gain control so that the detection voltages Vhave a given amplitude. A phase inversion circuit and a BTL amplifier circuit output a BTL voltage V, whose phase is opposite to the detection voltage Vand whose amplitude has been increased, to the detection electrodes via detection resistances. The AGC circuit reduces the detection voltages Vin order to prevent the drive voltage Vfrom exceeding a design upper limit value V'.

Vibrating gyro

An angular velocity detection apparatus includes an angular velocity detection signal amplifier circuit which amplifies an angular velocity detection signal Vo output from an angular velocity sensor, and an offset control circuit which controls an offset so as to be a reference voltage which is output when a value of an angular velocity is 0. The angular velocity detection apparatus further includes an input switch circuit which selects the reference voltage and a discharge switch circuit which short-circuits a capacitor included in a high-pass filter in an offset control period.

Angular velocity sensor interface circuit and angular velocity detection apparatus

In a method of setting temperature characteristics of an angular velocity sensor, temperature characteristics of a detuning frequency are acquired. The detuning frequency is a frequency difference between an oscillation frequency of an oscillation circuit including a piezoelectric vibrator and a frequency of a voltage of the piezoelectric vibrator caused by the Coriolis force. The sensitivity to the detuning frequency is acquired. The temperature characteristics of a detection phase are acquired. The detection phase is a phase difference between a Coriolis signal phase that corresponds to a phase angle of a voltage signal and an oscillation signal phase of the oscillation circuit. The sensitivity to the detection phase is acquired. The amount of phase shift of the detection phase is determined so that the change in sensitivity caused by the change in the detuning frequency with temperature is controlled using the change in sensitivity caused by the change in the detection phase with temperature.

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Toyama, Japan

Hideaki Sugibayashi