Hitachi, Ltd.

Hitachi Maxell, Limited

Hitachi Denshi Kabushiki Kaisha

Demix Technology Inc.

Akio Kumada

Yoshizumi Eto

Hiroshi Takano

Masao Hibi

Masashi Tanaka

Takahiko Ihochi

Shigeo Nakamura

Koji Ishida

Hideyuki Horiuchi

Daizo Tokinaga

Yasuo Kato

Makoto Homma

Takeo Seki

Masamoto Takatsuji

Tamotsu Shimada

Chiaki Shinbo

Masaru Yokosuka

Minoru Okada

Kazuma Suzuki

Yukio Shinoda

Tsutomu Ochiai

Takahiko Iochi

Shinsuke Miura

A piezoelectric revolving resonator is disclosed in which a piezoelectric ceramic material in the form of a disk, a cylinder or a pipe is polarized so that two regions divided by its diameter are different in polarity from each other, and electrodes are provided to form equipotential surfaces on opposite principal surfaces and a resonant condition in which piezoelectric deformations are revolved is excited by a single-phase alternating current voltage. Due to the single-phase drive, the structures of the resonator and the drive circuit can be simplified.

Piezoelectric revolving resonator and single-phase ultrasonic motor

A piezoelectric motor comprising a movable element having a first flat surface, vibration elements formed by combination of at least one twisting vibration member vibrating in a twisting manner and at least one piezoelectric element acting to vibrate the twisting vibration member. The vibration elements have a second flat surface adapted to abut against the first flat surface so that the movable element can be driven by surface contact between the first flat surface and the second flat surface.

Piezo electric motor

A piezoelectric revolving resonator comprising a circular or cylindrical transducer element, in which the center of gravity of the resonator revolves eccentrically around the center of an original circle as a result of resonance thereof upon excitation of the 1st order resonance frequency. Also, the ultrasonic motor is disclosed comprising a resonator of gravity center revolution type with the center of gravity thereof revolving in reversibly clockwise or counterclockwise direction and a rotor pressure fitted on the resonator, the motor utilizing the rotational torque received by the motor through a frictional force.

Piezoelectric revolving resonator and ultrasonic motor

A torsional mode ultrasonic vibrator is formed by integrally combining a piezoelectric thickness vibrating element and a cylindrical torsional mode resonator. Furthermore, a torsional mode piezoelectric motor is provided in such a manner that a rotor and a stator are pressed to each other so that a rotational torque can be generated by the vibration at the contacting surfaces therebetween and a piezoelectric thickness vibrator and a torsional mode ultrasonic vibrator formed by an integral combination of a torsion coupler and a torsional mode ultrasonic resonator are used as the source of the ultrasonic vibration.

Torsional mode ultrasonic vibrator

An ultrasonic motor having a cantilever type longitudinal/torsional vibration coupling element with a beam and a rotor rotated by the vibration of the beam. The rotor is provided with contacting surface for only contacting the beam in the outer peripheral portion of the surface of the beam away from the torsional vibration axis of the beam.

Ultrasonic motor using bending, longitudinal and torsional vibrations

Disclosed is a display device including a transparent piezoelectric element having transparent electrodes coated on both surfaces thereof, bonded by transparent adhesive material on an inner surface of a transparent cover to be arranged in front of a display panel of the display device. The transparent cover works as a vibration generator of a sound source. The thickness of the transparent electrodes are selected to serve as an anti-reflection layer of the near ultraviolet light. Relative dimensions of and positional relation between the transparent cover and the piezoelectric element are limited in predetermined ranges to assure high quality of display characteristic and sufficient volume of sound.

Display device with transparent cover as a vibrator of a sound generator

In a laser surgical apparatus having a laser oscillator operable to oscillate to produce a laser beam, and an optical path connected to the laser oscillator for transmission of the laser beam, a hand piece at the fore end of the optical path is equipped with a vibrator element comprised of a piezoelectric transducer, and the vibrator element applies a vibration to the hand piece.

Laser surgical apparatus

In a transducer including at least a piezoelectric ceramic plate which has curved surfaces, electrodes which are formed on both the main surfaces of the piezoelectric ceramic plate, a frame which holds the piezoelectric ceramic plate, and means for applying an electric signal to the electrodes; this invention is characterized in that the holding frame is made of an organic high-polymer resin. Since the piezoelectric ceramic plate has the curved surfaces and the holding frame is made of the organic high-polymer resin, the transducer is suitable as a loudspeaker for audio use having a wide frequency band.

Piezoelectric ceramic transducer

A display device structure comprising a casing, a display panel placed in the casing, a transparent covering and vibrating plate member on the front side of the display panel and an actuator for the plate member. The covering and vibrating plate member is carried on the casing through an elastic member interposed between the peripheral portion of the plate member and the casing. By this arrangement the plate member is capable of effectively generating sound outward upon reception of vibrating force from the actuator.

Display device structure

Disclosed is a transparent piezoelectric transducer comprising, at least, a transparent vibrator and at least one plate of a piezoelectric ceramic material sandwiched between a pair of transparent electrodes, said transparent vibrator being disposed so as to be vibrated by the piezoelectric ceramic material plate, said piezoelectric ceramic material being a ceramic material which is represented by a formula:

Ceramic transparent piezoelectric transducer

A piezo-electric bimorph type transducer of a cantilever type for controlling the scan tracking of a magnetic tape by a rotating head in a helical-scan-type video tape recorder. In this transducer, piezo-electric thin plates which constitute a piezo-electric bimorph are formed in a different shape from the electrodes attached to the piezo-electric thin plates, and the width of the electrodes is smaller than the width of the piezo-electric thin plates in the direction from a fixed end of the transducer toward a movable end of the same, whereby in the bimorph element, a predetermined relationship is attained between the bending moment produced by a control voltage applied to the electrodes and the innertia generated in a dynamic condition, and the displacement of the magnetic head caused by the piezo-electric bimorph type transducer is in static and dynamic conformity, so that the tracking control is correctly carried out.

Piezo-electric bimorph type transducer

This invention intends to provide a speaker which assumes a comparatively large area in a device without spoiling various display effects. The transparent flat panel speaker of this invention is a speaker of high efficiency which can give forth a sound volume large considering the small-sized device even when driven by a low voltage. The transparent flat panel speaker of this invention comprises, at least, a transparent resonator plate and a plate of a piezoelectric material held between at least one pair of electrodes, the resonator being excited by the piezoelectric material plate, a periphery of the resonator plate having a shape which is represented by a curve or in which straight lines are connected by smooth curves with at least two centers of curvature. As the peripheral shapes, an ellipse, a curve expressed by X.sup.n /a+Y.sup.n /b=1, a plane figure obtained by molding the corners of a polygon circumscribed or inscribed to an ellipse, etc. are especially favorable for the speaker.

Transparent flat panel piezoelectric speaker

In an electro-optical light shutter device using a solid-solution ceramic material for alternate transmission and interception of light, a first voltage is applied to the solid-solution ceramic material in the operating (open) position of the shutter, and a second voltage of polarity opposite to that of the first voltage and having an absolute value smaller than that of the first voltage is applied to the solid-solution ceramic material in the non-operating (closed) position of the shutter. The solid-solution ceramic material has a composition in which a ferroelectric phase and a non-ferroelectric phase adjoin each other through a morphotropic phase boundary.

Electro-optical light shutter device

An element in which only a single domain-wall can move sidewise, having a crystal plate of an irregular ferroelectric which is Z-plated at opposite surfaces and is then cut or cleaved in the &lt;110&gt; direction at its periphery and transparent electrodes for the polarization reversal provided at the central portions of the opposite Z-planes. The element includes at least a domain configuration such that two nucleus regions of opposite polarities are disposed on opposite sides of the region where the electrodes are provided.

Irregular ferroelectric element devised for single domain-wall motion

For dielectric matrix devices, plural stripe-shaped vertical and horizontal electrodes are crossed with each other respectively and disposed on the front surface of a predetermined dielectric plate, while on the back surface of said dielectric substrate independent electrodes are disposed on both the corresponding portions to the crossed areas of horizontal and vertical electrodes and the neighboring portions to these areas. The present dielectric matrix element is characterized in that the lead wire to the horizontal and vertical electrodes disposed on the dielectric substrate is connected to only one side of this dielectric substrate.

Growing community of inventors

Kokubunji, Japan

Akio Kumada