Murata Manufacturing Co., Ltd.

Kaneo Yaji

Shinji Kobayashi

Tomoyasu Hasegawa

Yoshitaka Kato

Tomio Shibano

Nobuhiro Ito

A vibrating sensor device is disposed on the obverse or reverse surface of a substrate. A signal processing circuit is disposed on the other surface of the substrate. First and second detecting wiring patterns, through which detection signals generated based on a vibration of a vibrator of the vibrating sensor device caused by a Coriolis force pass, extend from the vibrating sensor device in opposite directions. First and second driving wiring patterns for respectively allowing first and second driving signals, which are 180 degrees out of phase with each other, to pass therethrough extend from the vibrating sensor device in opposite directions. The above-described wiring patterns are disposed so that the capacitances between the adjacent wiring patterns become substantially equal to each other.

Vibrating gyroscope

An angular velocity sensor includes: a vibrator; a support for supporting the vibrator so as to be capable of vibrating; a driver for driving the vibrator by an electrostatic force; a detector for detecting a displacement of the vibrator based on a Coriolis force applied to the vibrator as a variation of electrostatic capacitance; and a capacitance-voltage converting circuit for converting the variation of the electrostatic capacitance detected by the detector into a voltage variation, the capacitance-voltage converting circuit being made as a source-follower circuit connected to a high-resistance gate resistor between a gate and a source using a JFET, and wherein the gate of the JFET is connected to a bias power supply via a bias resistor.

Angular velocity sensor

A miniature electrostatic capacitive sensor in which electrical insulation is reliably established between a CV conversion circuit and a sensing unit. Also disclosed is a manufacturing method for the above type of capacitive sensor. The capacitive sensor is constructed of a sensing unit having a movable electrode and a stationary electrode, and a CV-conversion-circuit-forming portion having a CV conversion circuit. The movable electrode is constructed of a first support portion, a leaf spring connected to the first support portion, and a mass portion movably supported by the leaf spring. The stationary electrode is formed of a second support portion and a projecting portion connected to the second support portion. The CV-conversion-circuit forming portion and the first and second support portion are made thin. Accordingly, a shallow clearance is formed between the CV-conversion-circuit forming portion and each of the first support portion and the stationary electrode. An insulating substance can thus be positively deposited in the clearance, thereby forming an electrically insulating portion between the CV conversion circuit and the sensing unit.

Electrostatic capacitive sensor and method for manufacturing the same

Electrostatic capacitive sensor

A capacitor type acceleration sensor is disclosed. In this sensor, an acceleration sensing element 1 has two variable capacitors C1 and C2 that are constructed with a couple of fixed electrodes and a movable electrode located between the fixed electrodes. Electrostatic power generation/feedback means 15 applies to the fixed- and movable-electrode pairs such an electrostatic power as to set the movable electrode at a preset reference position in accordance with the output signal of capacitance-difference detector means 10. The electrostatic power is outputted as an output signal of the capacitor type acceleration sensor. In the capacitor type acceleration sensor, another fixed capacitor Cx of which the capacitance value Cx is larger than the maximum capacitance-difference between the variable capacitors C1 and C2 of which the capacitance values vary in accordance with an acceleration, is connected in parallel with the variable capacitor C2. The capacitance (C2+Cx) is larger than the capacitance of the variable capacitor C1, irrespective of the direction of acceleration.

Growing community of inventors

Sagamihara, Japan

Kaneo Yaji