Fujitsu Corporation

Fujitsu Media Devices Limited

Other

Tamagawa Seiki Co., Ltd.

Fujitsu Towa Electron Limited

Masanori Yachi

Hiroshi Ishikawa

Yoshio Satoh

Hiroshi Tanaka

Yoshitaka Takahashi

Masaaki Ono

Kazutsugu Kikuchi

Sumio Yamada

Noboru Wakatsuki

Kazuhiro Ohta

Takashi Miyagawa

Kazuhiro Ota

Yoshiro Fujiwara

Yuki Endo

Keiji Saito

Toshinobu Hosokawa

Fumihiko Nakazawa

Toshio Hanazawa

Hiroaki Takagi

Kazutugu Kikuchi

Kenji Fukayama

Katsuhiko Takahashi

Yoshinori Uwano

Tomoaki Momose

Katsuhiro Sawada

Tsuyoshi Ogasawara

Takayuki Fujii

Kazutaka Araya

Takashi Kato

An angular velocity sensor includes: a package housing a vibrator to sense an angular velocity; a mounting portion mounting the package, the mounting portion having a first terminal for making a connection with the package; a second terminal for making an external connection, and a resin portion covering the first and second terminals so that a part of the first terminal and a part of the second terminal are exposed; and a cover having a joint portion made of a metal and covering the package, the cover being fixed to the mounting portion by joining the joint portion to a joint terminal made of a metal and provided to the mounting portion.

Angular velocity sensor with mounting portion and cover

An angular velocity sensor includes a tuning-fork vibrator having a base and multiple arms extending from the base. Two arms out of the multiple arms driven to vibrate have first end parts opposite to second end parts connected to the base. The first end parts being wider than the second end parts.

Method for fabricating an angular velocity sensor

An angular velocity sensor includes a tuning-fork oscillator that includes a base portion, arm portions extending from the base portion, and a pair of driving electrodes that are provided to extend from the front face and the back face to a side face of at least one of the arm portions.

Angular velocity sensor

An angular rate sensor includes a tuning-fork oscillator, a support portion, an oscillation absorption portion and a mounting portion. The tuning-fork oscillator has a base and arm portions extending from the base. The support portion supports the base of the tuning-fork oscillator at a front face thereof. The oscillation absorption portion is provided on a back face of the support portion opposite to the front face. The mounting portion mounts the support portion through the oscillation absorption portion.

Angular rate sensor

A detector is made up of a semiconductor integrated circuit in a part, and the semiconductor integrated circuit includes a driving circuit, an AC amplifier, a detection circuit and an amplifier circuit. An input resistor that is connected to input terminals of an operational amplifier includes an internal input resistor made up of a semiconductor integrated circuit element and an external input resistor made up of an external discrete component connected to each other in parallel. Temperature characteristics of an angular velocity sensor is compensated by a temperature coefficient (&#x3b1;) that is a combination of a temperature coefficient (&#x3b1;) of the internal input resistor and a temperature coefficient (&#x3b1;) of the external input resistor.

Sensor signal processing system and detector

An acceleration sensor includes a weight and a vibrator that supports the weight at its center of gravity. When acceleration is applied to the weight, stress equivalent to the applied acceleration is generated in the vibrator. As the vibrator is arranged to support the weight at its center of gravity, a characteristic relationship is observed between the acceleration, such as angular acceleration or translational acceleration, and the size of electric charges and the polarity. By taking advantage of this relationship, different types of acceleration can be easily detected.

Acceleration sensor

A sensor stem supporting a sensor element comprising a metal plate having a shape defined by press, the metal plate include a dent portion formed on a first surface of the metal plate, a step portion formed on a second surface of the metal plate facing the first surface, and a projection formed on the step portion for resistance welding. It is thus possible to obtain an excellent hermetic sealing of the sensor stem and a cap, which protects an oscillator, a circuit board and the like. The sensor stem can prevent a short circuit and can be lowered in height thereof.

Sensor stem, sensor device having the same, and method of manufacturing sensor device

An angular velocity sensor includes a stem and a vibrator that is supported by the stem. The vibrator is inclined to a mounting surface of the stem. The angle of inclination of the vibrator to the mounting surface is adjustable. For this reason, the angular velocity sensor also includes a holding member that holds the vibrator. This holding member is elastically deformable. A single material may be folded to shape the holding member.

A piezoelectric vibratorthat generates an electric charge according to a stress and a weightprovided on the piezoelectric vibratorare included. The piezoelectric vibratorhas multiple pairs of sensing electrodesand, andand, and the sensing electrodesand, andandare respectively connected in parallel so that capacitances Cdand Cdmade of the sensing electrodes may be connected in parallel. It is thus possible to double the charge sensitivity with keeping the voltage sensitivity.

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

An acceleration sensor which has a vibrator, a weight portion that is connected to the vibrator, and supported at a position different from the center of gravity of the vibrator plus its own structure, and a detecting section which detects the amount of characteristic corresponding to an angular moment that is exerted in the vibrator upon application of an acceleration in one direction to the vibrator and the weight portion. When an acceleration in one direction is applied to the vibrator and the weight portion connected thereto, an angular moment is exerted in the vibrator due to the difference between the supporting point of the weight portion and the center of gravity of the vibrator plus the weight portion, and the amount of characteristic corresponding to the angular moment is detected by the detecting section so that the acceleration of a linear motion is detected.

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 small-sized, high detection sensitivity and high performance acceleration sensor having directional or non-directional sensitivity is disclosed. The acceleration sensor is provided with a vibrator having uni-directional polarization and a weight connected to the vibrator. The weight is supported at the position different from the center of gravity of the total body of the vibrator and the weight itself. The vibrator is disposed so that its direction of polarization axis is either consistent or inconsistent with an axis of the torsion of the vibrator.

A tuning-fork vibratory gyro has first and second arms and a base integrally connected to the first and second arms. The gyro includes drive electrodes used to generate tuning-fork vibrations due to a piezoelectric transversal effect, and detection electrodes provided on the first and second arms and used to output a detection voltage due to an angular velocity.

Tuning-fork vibratory gyro

A piezoelectric actuator includes a main driver electrode and a sensor electrode A feedback signal is generated from the sensor electrode in order to eliminate a primary vibration mode due to a primary resonance frequency. The main driver electrode extends to a fixture portion of the actuator, the fixture portion being fitted into a support member The extending portion of the main driver electrode eliminates the electromechanical coupling against a secondary vibration mode due to a second resonance frequency. Features of the piezoelectric actuator suppress the resonance phenomenon, thus improving the response characteristics of the actuator.

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Yokohama, Japan

Masanori Yachi