Other

Rion Company Ltd.

The Institute of Physical and Chemical Research

Kureha Kagaku Kogyo Kabushiki Kaisha

Konica Minolta Medical and Graphic, Inc.

Rikagaku Kenkyusho

Kobayashi Institute of Physical Research

Kukamoto University

Munehiro Date

Kumamoto University

Date, Munehiro

Hidekazu Kodama

Eiichi Fukada

Kazunori Kimura

Tomonao Okubo

Kenji Suzuki

Kiyokazu Morita

Takashi Iwakura

Kenji Ohnuma

Yuichi Nishikubo

Fumitaka Funahashi

Ken'ichi Nakamura

Ippei Torigoe

Toshiaki Takamatsu

Takeo Furukawa

Shigeru Sakai

Takashi Segami

Pavel Mokry

Masayuki Kutani

In a laminated piezoelectric body, a laminated piezoelectric body manufacturing method, an ultrasound transducer, and an ultrasound diagnostic device according to the present invention, a plurality of mutually laminated piezoelectric bodies are electrically connected in parallel to each other, and each of the plurality of piezoelectric bodies arranges an orientation of residual polarization or a crystal axis that is related to an electrical displacement or a sign of an electric field due to a direct piezoelectric effect in a direction which reduces sensitivity in a first resonance mode and increases sensitivity in a second resonance mode of a higher order than the first resonance mode with respect to an axis of a first-level piezoelectric body on a fixed end-side.

Laminated piezoelectric body, laminated piezoelectric body manufacturing method, and ultrasound transducer and ultrasound diagnostic device using laminated piezoelectric body

An electromechanical transducer of the invention comprises a structural unit, an armature, and first and second elastic members. The structural unit includes at least one pair of magnets, a yoke conducting a magnetic flux generated by the magnets, and a coil supplied with an electric signal. The armature has an inner portion disposed to pass through an internal space of the structural unit and first and second outer portions protruding on both sides from the inner portion, and the armature constitutes a magnetic circuit with the structural unit via two regions through which components of the magnetic flux flow in directions opposite to each other in the inner portion. The first and second elastic members connect between the first and second outer portions of the armature and the structural unit, respectively.

Electromechanical transducer and electrocoustic transducer

An acoustic capacity measurement method for finding capacity of a container or object by removing effect of the surface area without using an approximate expression of acoustic impedance is provided. The acoustic capacity measurement method for finding capacity of a container includes a pressure change ratio calculating step, a rotation step, an oblique coordinate transformation step, and a capacity calculating step.

Acoustic capacity, volume, and surface area measurement method

A sound insulation/absorption structure, a sound insulation/absorption device, and a structure having these applied thereto and a member constituting the same, are capable of insulating or absorbing sound by stiffness control. The sound insulation/absorption structure comprises a film member, such as a polymer film or metal foil, and a frame body having at least one annular opening, the film member being fixed to the frame body, the section of the film member surrounded by the frame body being of a curved shape such as a dome, wherein the resonance frequency of the in-plane stretching of this curved shape is set at a frequency equal to or higher than the audible frequency band, so as to insulate or absorb sound by the elastic force of the film. The film member may be replaced by an acrylic, polyethylene terephthalate or other plastic plate, an aluminum or other metal plate, or a veneer or other plate member, molded into a curved shape, such as a dome, a semi-cylinder and a cone.

Sound insulation/absorption structure, and structure having these applied thereto

An elastic wave control element includes a piezoelectric material which is inserted into a propagation path for an elastic wave or installed in an oscillator to allow the elastic wave in a selected frequency to be damped, reflected, or transmitted. The piezoelectric material is provided with a pair of electrodes between which a negative capacitance circuit is connected to allow a loss factor of the negative capacitance circuit in a selected frequency or frequency band to be matched with a dielectric loss factor of the piezoelectric material.

Elastic wave control element using piezoelectric materials

A variably sound-absorbing device comprises a piezoelectric material 32 the peripheral portion of which is fixed to a frame 31 or the like, at least one pair of electrodes 34 formed on opposite surfaces of the piezoelectric material, and at least one circuit element 36 through which the electrodes are connected to each other. The piezoelectric material 32 is boardlike and curved, and an electrical characteristic of the circuit element 36 (a circuit showing a negative capacitance for example) is variable. The modulus of elasticity (the real number part of the modulus of elasticity) and the loss factor (the imaginary number part of the modulus of elasticity) of the piezoelectric material are thereby varied and the sound-absorbing characteristic is electrically varied to a considerable extent.

Variably sound-absorbing device

The elastic modulus of a piezoelectric substance is controlled over a wide range using a simple method. The effective modulus (the real part of the elastic modulus) and the energy loss modulus (the imaginary part of the elastic modulus) of the piezoelectric substance are changed by installing electrodes on the surface of the piezoelectric substance and by connecting a mechanism consisting of one or more circuit elements to each of the electrodes.

Methods for controlling the elastic modulus of piezoelectric substances

A process for preparing polyvinylidene fluoride type (PVDF) films having highly stable piezoelectricity and pyroelectricity, by stretching PVDF films, while causing corona discharge, across the electric field formed by discharging, to effect thereby to polarization of film.

Piezoelectric and pyroelectric polymer film and process for preparing

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Tokyo, Japan

Munehiro Date