Murata Manufacturing Co., Ltd.

Asahi Kasei Microdevices Corporation

Murata Manufacturingco., Ltd.

Asahi Kasei Emd Corporation

Akira Mori

Takeshi Nakamura

Akira Kumada

Yoshitaka Kato

Makoto Narita

Yoshiaki Heinouchi

Nobuyuki Ishitoko

Kazuhiro Ebara

Isao Toyoshima

Yoshio Kawai

Yukio Sakashita

Iku Nagai

Katsumi Fujimoto

Kenjiro Okaguchi

Yoshihiko Koizumi

Takayuki Shimamoto

Satoshi Ichihara

Jiro Miyazaki

Kazuhiro Yoshitani

Kazushige Sawada

Yoshitaka Katou

An inertia force sensor that shortens a time from power activation until inertia force can be detected includes an oscillator, an oscillation circuit unit, and a detection circuit unit. The oscillation circuit unit functions as a closed loop self oscillation circuit with the oscillator as a resonant element, and includes a CV conversion circuit converting a monitor signal based on electrostatic capacitance according to an oscillating state of oscillator into a monitor signal based on a voltage corresponding to an amount in change of the electrostatic capacitance, and an automatic gain control circuit controlling gain based on the monitor signal converted at the CV conversion circuit to generate a driving signal, and supplying the driving signal to the oscillator. The CV conversion circuit includes an amplifier that amplifies a monitor signal with an amplification factor for a predetermined period after power activation.

Oscillation type inertia force sensor

An oscillation type inertia force sensor includes an oscillator, an oscillation circuit unit, and a detection circuit unit. The oscillation circuit unit functions as a self oscillation circuit of a closed loop with the oscillator as a resonant element, and includes an AGC circuit. The AGC circuit includes a VGA circuit, a comparison circuit comparing a predetermined reference voltage with a voltage of the monitor signal to output a control signal based on the compared result, and a pulse width modulation circuit modulating the control signal to a pulse width modulation signal. Based on the pulse width modulation signal, the driving signal is modulated with the output of the VGA circuit switched between an ON state and OFF state to control the degree of the amplification factor of the VGA circuit.

An external-force detecting apparatus includes at least one drive line connecting the corresponding drive electrodes to a driving unit and at least one monitor line connecting the corresponding monitor electrodes to the driving unit. The driving unit outputs a drive signal to the at least one of the drive electrodes through the at least one of the drive lines to drive an oscillator and performs automatic gain control to the level of the drive signal based on the oscillation state of the oscillator acquired from the at least one of the monitor electrodes through the at least one of the monitor lines. The external-force detecting apparatus further includes a switching circuit arranged to switch between connection and disconnection of an electric path between the oscillator and the driving unit via at least one of the drive lines or the multiple monitor lines.

External-force detecting apparatus and method of detecting line break

The oscillation type inertial force sensor includes an oscillator arranged to detect an inertial force, an oscillation circuit unit arranged to drive the oscillator, and a signal processing circuit unit arranged to generate a signal according to the magnitude of the inertial force on the basis of a detection output of the oscillator, and further includes a holding arranged to hold a processed signal in the signal processing circuit unit at a predetermined potential during a period immediately after power-on until operation of the oscillation circuit unit becomes stable in response to power-on.

Oscillation type intertial force sensor

A capacitance-sensing vibratory gyro includes a capacitance-sensing circuit that detects changes in capacitances of a sensing element. The capacitance-sensing circuit includes two operational amplifiers. The inverting input terminal of each operational amplifier is connected to the corresponding sensing electrode in the sensing element. A bias voltage generated by dividing a power supply voltage with resistors is applied to the non-inverting input terminals of the operational amplifiers. The bias voltage is applied to each sensing electrode by imaginary short-circuiting in the operational amplifiers so that the bias voltage directly depends on the power supply voltage.

Capacitance-sensing vibratory gyro and method for detecting change in capacitance

A vibrating gyroscope includes a vibrator having a longitudinal direction and being capable of vibrating in a bending mode in a bending direction perpendicular to the longitudinal direction. The vibrator has first and second nodes which elongate in a direction perpendicular to both the bending direction and the longitudinal direction and first, second, third and fourth supporting members connected to the vibrator such that the first node is interposed between the first and second supporting members and the second node is interposed between the third and fourth supporting members. The first node is located at the vicinity of either the first supporting member or the second supporting member, and the second node is located at the vicinity of either the third supporting member or the fourth supporting member.

VIBRATING GYROSCOPE AND ELECTRONIC DEVICE USING THE SAME HAVING A DRIVING CIRCUIT, A DETECTION CIRCUIT AND FOUR SUPPORTING MEMBERS WITH DIFFERENT RIGIDITIES, DIFFERENT SHAPES, DIFFERENT CROSS SECTIONS, DIFFERENT MATERIALS AND DIFFERENT LENGTHS

A gyroscopic apparatus includes two gyro sensors having substantially the same structure. The two gyro sensors are arranged on first and second major surfaces, respectively, of a mounting base so that the gyro sensors have an approximately 180-degree rotation symmetry about a virtual rotation axis penetrating the mounting base substantially parallel thereto in the same direction as rotation detecting axes. The outputs of the two gyro sensors are added, and the sum is output. Thus, the output of the gyroscopic apparatus is much less susceptible to impact from a specific direction, and a high detection accuracy can be maintained.

Gyroscopic apparatus and electronic apparatus including same

A compact vibrator support structure has a very high &ldquo;vibration confinement effect&rdquo;, and includes a vibrator, vibrator support members, and a vibrator base, which supports the vibrator in midair via the vibrator support members and is made of a material having a specific gravity of about 3.0 or above. Since the high vibration confinement effect of the vibrator support structure reduces leakage of vibration from the vibrator base, the stability of the vibration of the vibrator is greatly improved, thereby increasing the detecting accuracy of angular velocity. This eliminates the need to enlarge the vibrator base or to adhere a weight thereto, resulting in a miniaturized vibrating gyroscope.

Vibrator support structure, vibrating gyroscope therewith, and electronic device using the same

A vibrating gyroscope includes a vibrator having a driving electrode and a sensor electrode, a driving circuit for applying a driving voltage to the driving electrode, a detection circuit which receives, from the sensor electrode, a signal corresponding to a bending displacement of the vibrator, a signal processing circuit for processing a signal input from the detection circuit to detect an angular velocity, a power supply circuit, and a diagnostic circuit for examining whether or not the detection circuit, the driving circuit, the signal processing circuit, and the power supply circuit are all functioning normally.

Vibrating gyroscope and electronic device using the same

A vibrator has a construction that allows its electrodes to be easily formed and requires a smaller number of the assembly man-hours. The vibrator includes a drive electrode and two detection electrodes that are disposed along a length direction thereof, on a planar portion provided on the surface of a vibrating member defined by piezoelectric body. These electrodes constitute interdigital electrode portions defined by mutually opposed comb electrodes which are arranged such that the direction in which the teeth thereof extend is substantially perpendicular to the length direction of the vibrating member.

Vibrator, vibration gyro using the vibrator, and electronic device using the vibration gyro

A vibrating gyroscope includes supporting members which are fixed in the vicinity of two node axes n and n of a bar-shaped vibrator. The supporting members corresponding to node axis n extend from the locations at which they are fixed to the vibrator in the widthwise direction of the vibrator, and also include bending portions and a proximity portion. The bending portions bend toward node axis n At the proximity portion, the supporting members are in close proximity with each other with a gap therebetween in the vicinity of node axis n

Vibrating gyroscope and electronic unit using the same

A self-diagnosing circuit for a vibrating gyroscope for detecting a vibration due to a Coriolis force including a differential operating circuit for determining a difference between output signals outputted from a plurality of detecting electrodes which provided on the vibrator to detect the vibration due to the Coriolis force; and an offset signal source for superposing an offset signal on at least one of the signals outputted from said plurality of detecting electrodes such that the signals are offset with different signal levels.

Self-diagnosing circuit for vibrating gyroscope

A vibrating gyroscope includes a vibrator having a plurality of piezoelectric members stacked and polarized in directions opposing each other; at least one drive electrode formed on one of the mutually opposing main surfaces of the vibrator to input a signal for exciting the vibrator; at least two detection electrodes formed on one of the mutually opposing main surfaces of the vibrator to output a signal in accordance with vibration of the vibrator; and at least one reference electrode formed on one of the mutually opposing main surfaces of the vibrator to be connected to a reference potential. The reference electrode is formed in a position opposing the drive electrodes and the detection electrodes.

Vibrating gyroscope

A protection plate,and a protection plate,which are each of a substantially rectangular shape and which extend upwards from respective substantially central portions of opposite lengthwise ends of an attachment platform,are formed in the attachment platform,by bending part of the attachment platform,Also, stoppers,and,which have notches,for protecting two surfaces on either side of the ridge line of the oscillator,are attached to the attachment platform,Further the oscillator,the attachment platform,and the stoppers,and,etc. are housed in a box-shaped case,Accordingly, the vicinities of both lengthwise ends of the oscillator,are surrounded and protected by the stoppers,and,The protection plates,and,and the inner side surface of the case,as the protection members in the predetermined space d. By means of this structure, an oscillation gyroscope is provided in which the shock resistance is further improved.

Oscillation gyroscope

A vibrating gyroscope includes a bar-shaped vibrator and a support member. The bar-shaped vibrator includes a drive element for vibrating the bar-shaped vibrator and a detection element for detecting the vibration of the bar-shaped vibrator. The bar-shaped vibrator has two grooves therein which extend along a direction perpendicular to a longitudinal direction of the bar-shaped vibrator in the vicinity of two node points of the vibration of the bar-shaped vibrator, respectively. The support member has a shape in which two arch portions held in a non-horizontal direction are connected by two connecting portions at both ends of the arch portions. The arch portions of the support member are connected to the bar-shaped vibrator at respective bottoms of the grooves thereof.

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Nagaokakyo, Japan

Akira Mori