Tohoku Metal Industries

Nihon Dempa Kogyo Co., Ltd.

Research Development Corporation of Japan

Kokusai Electric Co., Ltd.

Tokin Corporation

Hiroshi Shimizu

Hiroshi Watanabe

Tsuyoshi Masumoto

Noboru Tsuya

Kenichi Arai

Tetsuo Yoshida

Yoshifusa Ueno

Hiroaki Ishii

Chikara Mashiko

Koji Asano

Tadashi Kanda

Yuji Iseki

Yuji Suzuki

In a piezoelectric gyroscope system wherein a vibrating body is vibrated in a specific direction by a piezoelectric actuator and is subjected to another vibration in a direction perpendicular to the specific direction due to the Coriolis' force upon being subjected to a rotation of a rotational speed, the perpendicular vibration being detected as an electric signal representative of the rotational speed by a piezoelectric transducer, the vibrating body is made of a circular rod of a piezoelectric material having a plurality of elongated electrodes on the outer surface of the rod, in order to resolve difficulty for mounting piezoelectric transducers onto the vibrating body. A driving signal is applied to predetermined ones of the electrodes to vibrate the rod in a particular diametric direction and an output signal is detected from specific ones of the electrodes according to the vibration due to the Coriolis' force. When an even number of electrodes are provided, those electrodes are formed at equiangularly spaced positions on the outer surface of the rod. When an odd number of electrodes are provided, those electrodes are formed at equiangularly spaced positions within an angular region of (360 angular degrees.times.2/3) on the outer surface of the rod.

Gyroscope using circular rod type piezoelectric vibrator

A surface acoustic wave resonator having an interdigital transducer on a piezoelectric substrate. Grating reflectors, which have electrode strips of the same width and the same pitch as those of electrodes of the interdigital transducer and of a number smaller than 1/5 that of said electrodes of said interdigital transducer, are disposed at the intervals equal to said pitch at both sides of said interdigital transducer on a surface wave propagation path. The electrode portion of the interdigital transducer is weighted so that the aperture of the interdigital transducer is maximum at the center of the interdigital transducer and uniformly decreases toward its both sides along respective sides of a rhombus with its vertices at the centers of the outermost electrode strips of the grating reflectors.

Surface acoustic wave resonator

A crystal resonator with plural electrodes comprises a crystal piece, first, second and third pairs of electrodes. The crystal piece causes shear vibration. The first electrode pair is provided in the center of the crystal piece and coupled to a variable impedance. The second and third electrode pairs are provided on both sides of the first electrode pair. The second and third electrode pairs are electrically connected together and are coupled to an oscillation circuit.

Crystal resonator with plural electrodes for use in a crystal

A multimode piezoelectric mechanical filter using edge-mode piezoelectric transducers, each comprising a semi-infinite or long piezoelectric plate polarized in the thickness direction, and a pair of exciting electrodes formed on the plate at an end portion thereof. Input and output edge-mode transducers are supported at their other ends together with optional resonator elements. The transducer and/or resonator elements are mechanically coupled with one another by a coupling rod at their end portions opposite the support to transmit the edge-mode vibration from one to the other. All of the transducers and resonator elements may be disposed in a common plane and may be integrally formed by punching a single piezoelectric plate to form a monolithic type mechanical filter. In such monolithic type filter, coupling rods are also integrally formed with the transducers and resonators. Alternatively, the transducer regions and/or resonator regions are separated and defined by a slit or slits formed in a large square piezoelectric plate, the bottom portion of each slit being usable as the mechanical coupling.

Multiple resonant electromechanical filters using edge-mode vibration of

A piezoelectric resonator of a width-extensional mode vibratory-energy trapping type having a rectangular piezoelectric plate of a width corresponding to a desired resonance frequency. Peripheral electrodes are deposited apart from one another in its lengthwise direction to cover over the width of opposite end portions of the piezoelectric plate in order to lower the cut-off frequency of the opposite end portions of the piezoelectric plate in comparison with the intervening central portion of the plate, so that the width-extensional mode vibratory energy may be trapped or confined within the central portion of the piezoelectric plate. The resonator can be supported and are connected to lead wires at peripheral electrodes. In the piezoelectric plate polarized in its width direction, two excitation electrodes are provided on a surface of the central portion of the piezoelectric plate in parallel with one another, one connected with one of the peripheral electrodes and the other connected to the other peripheral electrode. A set of two excitation electrodes and two spaced peripheral electrodes may be formed on the reverse surface of the piezoelectric plate in registry with those electrodes on its opposite surface. A stray strip-like electrode may be formed between the two excitation electrodes of one surface of the piezoelectric plate. In the case, the stray electrode and two excitation electrodes are disposed so that centers of respective distances between respective adjacent electrode is corresponding to zero point of stress distribution due to the third-harmonic-mode vibration to suppress the third harmonic mode. In the piezoelectric plate polarized in its thickness direction, four peripheral electrodes are formed on the opposite surfaces of the piezoelectric plate, and peripheral electrodes at each end portion are short-circuited with one another. Excitation electrodes are formed on the central exposed regions of the plate intervening between peripheral electrodes. Two excitation electrodes may be formed on each surface of the plate, and are disposed at positions corresponding to zero points of stress distribution due to the third-harmonic mode vibration to suppress the third-harmonic mode.

Piezoelectric resonators of an energy-trapping type of a width

An electric signal transmission transducer employing a ferromagnetic amorphous ribbon and especially an electric signal transmission element and system and an electroacoustic signal conversion system using a ferromagnetic amorphous ribbon. The transmission transducer also provides for applying a magnetic field to the ferromagnetic amorphous ribbon for controlling the electric signal transmission or delay time. Also shown are the electric and magnetic characteristics of ferromagnetic amorphous ribbons after various heat treatments in various magnetic fields.

Electric signal transmission device employing a ferromagnetic amorphous

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Sendai, Japan

Hiroshi Shimizu