Abstract: An ultrasonic wave transmitter/receiver is provided in which the transmission/reception range thereof in at least one direction is relatively narrow, and which has stable reverberation characteristics. When the thickness of a thick-walled portion is t1, the thickness of each of thin-walled portions is t2, the thickness of a side portion provided continuously with the thin-walled portion is A, x=t2/t1, and y=A/t2, this ultrasonic wave transmitter/receiver is formed so that x and y are within the range defined by the following equations:
Abstract: The present invention provides a piezoelectric vibrator, in which there is no significant change in the characteristics even when depole occurs due to heat shock and the like. The piezoelectric vibrator includes a first piezoelectric substrate having split electrodes formed on one main surface thereof and a second piezoelectric substrate having a common electrode formed on one main surface thereof. The remaining main surfaces of both piezoelectric substrates are bonded to each other via an intermediate electrode. The material of the first piezoelectric substrate differs from the material of the second piezoelectric substrate. As a result, the difference (longitudinal DF) between a resonant frequency and an anti-resonant frequency in a longitudinal vibration of the piezoelectric vibrator substantially coincides with the difference (transverse DF) between a resonant frequency and an anti-resonant frequency in a transverse vibration thereof.
Abstract: In a piezoelectric resonator container having a cylindrical case, one end of which is an open end, and a stem for sealing the open end of the case, an outer peripheral face of the stem and an inner peripheral face of the case have a nearly elliptical shape or an elliptical shape, respectively. A pressure allowance when pressing the stem into the open end of the case monotonically increases from a major axis portion of the case toward a minor axis portion. Therefore, since the pressure allowance is large at minor axis portions where vertical stress tends to decrease and the pressure allowance is small at major axis portions where tensile stress tends to increase, incomplete gas-tightness due to inadequate sealing or breaking of the case does not occur. This provides a piezoelectric resonator container in which incomplete gas-tightness is not caused, even if an elliptical or a nearly elliptical case is used, and a piezoelectric resonator piece does not come into contact with the inner periphery of the case.
Abstract: In a self-excited oscillator circuit, a buffer is connected to an electrode or electrodes, and a buffer and an inverter are connected to an electrode or electrodes. Each of the inverters and and the buffer has a tri-state configuration and is capable of setting an output terminal in a high-impedance state, i.e., turning off an output signal, according to a signal input to a control terminal. Therefore, it is possible to turn off a drive circuit and the ultrasonic motor by setting the inverter in the high-impedance state. It is also possible to change the direction of movement of the moving member by setting one of the buffer and the inverter in the high-impedance state.
Abstract: A piezoelectric adjusting mechanism includes a piezoelectric displacing element that is placed in contact with a cutting element and that is provided for displacing the cutting element with regard to a tool shaft. The mechanism also includes a holding mechanism for holding the first displacing element in a determined deformation state. The piezoelectric adjusting mechanism can be used, in particular, for a fine boring tool in order to adjust cutting elements, the elements being arranged on the outer periphery of the fine boring tool, in a radial direction of the fine boring tool.
Abstract: The piezoelectric transformer of the present invention has a piezoelectric element 109 mainly formed of a piezoelectric material, primary electrodes 101U and 101D which are formed on the piezoelectric element 109 and to which a voltage is applied, a secondary electrode 102 which is formed on the piezoelectric element 109 and from which a voltage higher than the voltage applied to the primary electrode is output, and a sensor electrode 103 which is formed on the piezoelectric element 109 and from which a voltage lower than the output voltage of the secondary electrode is output.
June 5, 2000
Date of Patent:
June 24, 2003
Matsushita Electric Industrial Co., Ltd.
Abstract: There is provided an apparatus that shows a much better transmission function characteristic in a signal passing band, and a low insertion loss. A plurality of pairs of electrode fingers constitute a first split electrode group of 5a1, 5b1, 5a2, 5b2, 5a3, 5b3, . . . . Further, a plurality of pairs of electrode fingers constitute a second split electrode group of 6a1, 6b1, 6a2, 6b2, 6a3, 6b3, . . . . The pairs of electrode fingers of both the groups are interleaved. The pairs of electrode fingers include electrode fingers of a width narrower than &lgr;/8 (&lgr; indicates the wavelength of a surface acoustic wave serving as the operation central frequency), and electrode fingers of a width wider than &lgr;/8, and the distance between the centers of the adjacent electrode fingers differs from &lgr;/4.
Abstract: There is disclosed a piezoelectric single crystal wafer wherein an etching pit density on the front surface of the wafer on which an electrode for transmit-receive of surface acoustic wave or leaky surface acoustic wave is formed is 7.8×104/mm2 or less, and a piezoelectric single crystal wafer wherein surface roughness Ra on the peripheral surface other than the front surface and the reverse surface of the wafer is 2.3 &mgr;m or less. There can be provided a piezoelectric single crystal wafer wherein a deviation of surface acoustic wave velocity or leaky surface acoustic wave velocity is small, namely the uniformity of the velocity is excellent, and fine contaminations adhered on the surface where electrode is formed and breakage of the wafer can be significantly reduced, and therefore a device such as a filter having excellent property can be produced in high yield.
Abstract: A highly compact piezoelectric resonator having excellent resonant characteristics and very small resonant resistance includes an upper electrode disposed on one of two main surfaces of a piezoelectric film and a lower electrode disposed on the other main surface of the piezoelectric film. The upper electrode includes a first external-signal extracting electrode, a first leading electrode, and three first vibrating electrodes. The lower electrode includes a second external-signal extracting electrode, a second leading electrode, and three second vibrating electrodes. The three first vibrating electrodes are arranged substantially perpendicularly to the three second vibrating electrodes via the piezoelectric film. Vibrating sections are located at positions where the first vibrating electrodes are arranged substantially perpendicularly to the second vibrating electrodes.
Abstract: A piezoelectric actuator has a plurality of disks made of piezoelectric material, arranged to form a stack in a stack direction, a plurality of flat inside electrodes arranged in alternation with the disks made of piezoelectric material, and at least two outside electrodes applied to the outside of the stack along the stack direction, the inside electrodes each being connected in alternation to one of the outside electrodes by a contact zone. The outside electrodes are applied to the outside of the stack in the form of a coating of an elastic, electrically conductive polymer material.
Abstract: A bending transducer has a piezoelectret carried on a substrate of electrically insulating material. An electrically conductive coating, such as a foil, a grid foil, a grid mesh, or mutually parallel strips, connects the inner electrode of the piezoelectret to the substrate and forms electrical contact with the inner electrode at a number of points. The bending transducer is particularly suited for driving a drafting, weaving or knitting machine in the textile industry.
Abstract: A piezoelectric/electrostrictive device (P/E) includes driving, movable and fixing portions. One end of a first P/E element and P/E operating portion on the end are positioned on the fixing portion and an opposite end of the P/E operating portion of the first P/E element is positioned on a first thin plate portion. One end of a second P/E element and P/E operating portion on the end are positioned on the movable portion and an opposite end of the P/E operating portion of the second P/E element is positioned on a second thin plate portion. A hole formed by inner walls of the driving, movable and fixing portions has a central axis that extends in an axial direction substantially parallel to the thin plate portions and substantially perpendicular to the length direction, and the device is free of any other holes extending in any direction other than the axial direction.
August 21, 2000
Date of Patent:
May 27, 2003
NGK Insulators, Ltd.
Yukihisa Takeuchi, Tsutomu Nanataki, Masato Komazawa, Koji Kimura
Abstract: The present invention relates to an elastic surface-wave device, and more particularly to an elastic surface-wave device of a greatly increased performance, compared with a prior art elastic surface-wave device, and which is compact. The elastic surface-wave device includes a substrate including a surface having a region which is formed by at least a part of a spherical surface and is circularly continuous, and a surface acoustic wave generator which is provided in the surface region of the substrate and generates surface acoustic waves propagating in a continuous direction of the surface region. The surface acoustic wave generator generates surface acoustic waves in such a manner these waves can propagate only in the continuous direction without being diffused in a direction crossing the continuous direction along the surface region.
Abstract: A capacitive actuator is charged from a charged energy storage capacitor via a transformer by applying pulse width-modulated control signals with a specific voltage, frequency and duty ratio to a charging switch disposed on the primary side. The duration, magnitude and waveform of the actuator voltage can in this case be chosen as required. The actuator can be discharged in the same way.
Abstract: A passive piezoelectric damping system dissipates mechanical energy propagating through a structure by tuning a shunt inductance to a non-resonant mode of the structure. The damping system includes a piezoelectric element coupled to the structure, where the piezoelectric element converts the mechanical energy into electrical energy. The electrical energy has a reactive component. The damping system further includes a shunt circuit connected to the piezoelectric element for balancing the reactive component of the electrical energy with a shunt inductance. The shunt inductance is tuned to a non-resonant mode of the structure to reduce airborne noise transmission through the structure.
Abstract: A stacked electro-mechanical energy conversion element includes a plurality of layers made of a material having an electro-mechanical energy conversion function on which a plurality of electrode areas are formed, a first layer having an electro-conductive portion formed from the electrode area to a side face which is a non-stacked surface area, a second layer having a through-hole formed therein by an electro-conductive member, a third layer having an electro-conductive film which communicates the electro-conductive portion of the first layer and the through-hole of the second layer, and an external electro-conductive film formed on the side surface of the first layer so as to communicate with the electro-conductive portion.
Abstract: High quality epitaxial layers of piezoelectric material materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.
July 24, 2000
Date of Patent:
April 29, 2003
Jeffrey M. Finder, Kurt Eisenbeiser, Jamal Ramdani, Ravindranath Droopad, William Jay Ooms
Abstract: A surface acoustic wave device includes a surface acoustic wave substrate having two IDT electrodes including wiring electrode portions made of aluminum disposed thereon. First, second and third metal films are laminated on each of the wiring electrode portions. The first metal film has superior bondability to aluminum, and the third metal film has superior bondability to bumps. In addition, the second metal film has an ability to suppress the diffusion of the metal defining the first metal film.
Abstract: An actuator for a control valve includes a piezoelectric actuating member for bringing about the movement of a closure member of the valve between an open position and a closure position; the member has a reference portion for connection to a fixed portion of the device and a free portion for connection to the closure member, the free portion being movable relative to the reference portion as a result of mechanical deformations produced in the actuating member by the piezoelectric effect. The reference portion of the actuating member is controllable selectively between a condition in which it is locked in a reference position and is fixed firmly to the fixed portion of the device, and a free condition in which it is movable relative to the fixed portion.
Abstract: A ceramic diaphragm structure includes a ceramic substrate having at least one window portion, and a thin ceramic diaphragm plate laminated so as to cover the window portion, wherein the ceramic diaphragm structure is unitarily formed so that the thin ceramic diaphragm portion is protruded in the direction opposite to the window portion, and a ceramic connecting layer connects the thin ceramic diaphragm plate to the ceramic substrate. The ceramic diaphragm structure has a high resonance frequency, an enhanced strength, an excellent quality and a high reliability.