Abstract: The present invention realates to an ultrasonic transducer providing a plurality of arranged vibrators as the piezoelectric materials. The present invention easily provide the shading to the polarization in the elevation direction of the piezoelectric materials in order to narrow the beam transmitted from the transducer. For this purpose, a structure of the present invention provides for the polarization (V.sub.1, V.sub.2, V.sub.3) of piezoelectric material of arranged vibrators to be gradually reduced in mass like a staircase from the center of the arranged vibrators to both end portions in the direction orthogonally crossing the arrangment direction of a plurality of arranged vibrators.

Abstract: On a first piezoelectric sheet of a piezoelectric vibrator, a second piezoelectric sheet is stacked with interposition, between the sheets, of first-set electrodes (24(1), 24(2)) formed on an upper surface of the first piezoelectric sheet. Second-set electrodes are formed on an upper surface of the second piezoelectric sheet with each placed halfway between two adjacent ones of the first-set electrodes. The second piezoelectric sheet is poled in directions from each second-set electrode to the two adjacent ones of the first-set electrodes. Preferably, third-set electrodes are formed on a lower surface of the first piezoelectric sheet with each arranged halfway between two adjacent ones of the first-set electrodes. In this event, the first piezoelectric sheet is poled in directions from each third-set electrode to two adjacent ones of the first-set electrodes.

Abstract: A planar polarizable body is poled by placement between removable patterned plates which have conjugate patterns of open apertures and subjecting the open apertures to an electric field of the same polarity on opposite sides of the body, the field being of sufficient magnitude to induce polarization of the body material in opposite directions through the thickness dimension of the body with regions of alternate polarity at different lateral locations across the surface of the body in a desired pattern.

Abstract: In a piezoelectric ink jet printer head having a laminated piezoelectric layer, actuating voltage is applied between only electrodes corresponding to a selected jetting device. A part of the piezoelectric ceramic layers between the electrodes is deformed in accordance with a slip effect, to jet ink from the selected jetting device. Since the polarization direction of the piezoelectric ceramic layers is almost perfectly perpendicular to the direction of an actuating electric field, the actuating voltage can be reduced. Further, piezoelectric ceramic layers can be stacked to obtain the necessary strength of a laminated piezoelectric element without decreasing the displacement amount. Thus, the reliability of the laminated piezoelectric element is enhanced. Moreover, the insulation of the electrodes is not deteriorated by a short circuit, migration of silver or the like. Such properties as durability and moisture resistance are also enhanced.

Abstract: A piezoelectric transformer includes a substrate of piezoelectric material, preferably a single crystal of LiNbO.sub.3. The substrate is uniformly polarized in a selected direction thereof and vibrated in a direction of the length thereof. An input voltage is applied across both sides of a portion of the substrate in a direction of the thickness thereof and thus excites a vibration by way of piezoelectric effect. Thereby another voltage is caused in the direction of the thickness of the substrate in a portion other than the portion to which the input voltage is applied, and taken out as an output voltage. As a result, it is possible to decrease the output impedance to obtain a large load current and thus fully heighten a step-up ratio of the piezoelectric transformer.

Abstract: A piezoelectric transducer having a solid body with electrode strips either attached to the body or embedded within it. The electrodes are electrically isolated from each other on the body of the transducer and are arranged in a pattern so that they may be selectively connected to a voltage source to produce electromechanical forces within the body, thereby causing associated vibrations of the body. Initially, the electrode strips are used to polarize the transducer. During operation of the transducer as a vibration source, the electrode strips are used to connect an applied voltage having a polarity opposite to that of the polarizing voltage on one face of the body. The transducer is especially useful for producing flexural vibrations, but a number of other vibration modes of operation are possible. The transducer is operable either as a vibration source or as a sensor.

Abstract: A piezoelectric device includes a first electrode, a second electrode disposed in opposing, spaced relation to the first electrode, a ferroelectric liquid crystal interposed between the first and second electrodes, a first alignment layer formed between the first electrode and the ferroelectric liquid crystal, and a second alignment layer formed between the second electrode and the ferroelectric liquid crystal.

Abstract: A piezoelectric device includes a first electrode, a second electrode disposed in opposing, spaced relation to the first electrode, a ferroelectric liquid crystal interposed between the first and second electrodes, a first alignment layer formed between the first electrode and the ferroelectric liquid crystal, and a second alignment layer formed between the second electrode and the ferroelectric liquid crystal.

Abstract: A ladder type piezo-electric filter comprising series piezo-electric resonators and parallel piezo-electric resonators having improved second harmonic mode, high resonance response and anti-resonance impedance near 1-7 MHz, for use in communication applications requiring filter shaving resonator dimensions less than 5 mm and operating frequencies in excess of 455 kHz.

Abstract: Piezoresistive material, useful as a sensing agent for mechanical deformation undergone by pieces or structures when they support loads during their normal operation, consists essentially of a substantially homogeneous solid mixture of three or more components, including a piezoresistive element, a conducting element and a binding element. Said piezoresistive material is also useful for manufacturing various transducers, the function of which is based on elastic deformation.

Abstract: A piezoelectric transducer useful for example as a sound source or a strain detector includes a ferroelectric liquid crystal sealed between two baseplates with electrodes and alignment layers on the inner facing surfaces of the baseplates. One of the baseplates is thicker than the other, or is of a different material, so that the two baseplates have different flexural rigidity.

Abstract: A piezoelectric power supply for a fuze assembly includes a stacked array of piezoelectric ceramic discs, a hollow can for holding the stacked piezoelectric discs, flexible electrical circuits interposed between the discs and the interconnecting respective positive and negative faces of the discs. The can is deformable upon receipt of a predetermined pressure impulse for transmitting the pressure to the discs. The flexible circuits conduct electrical current and provide positive and negative terminals for supplying electrical power upon deformation of the can and the piezoelectric discs by the pressure impulse.

Abstract: A ferroelectric ceramic transducer having low density, high compliance and improved electrical properties achieved by the absence of any solid or liquid material in the spaces between the lateral sides of the ferroelectric ceramic posts of the transducer. The ceramic volume-fill of the posts is no greater than sixty percent.

Abstract: Disclosed is a vinylidene cyanide copolymer obtained by copolymerization of vinylidene cyanide and two kind of vinyl compounds.By formation of a ternary copolymer, a monomer difficultly copolymerizabke with vinylidene cyanide can be incorporated into the polymer, and high piezoelectric performance can be obtained when polarized.

Abstract: An apparatus for poling a piezoelectric ceramic includes a first and a second electrode which are connected to a DC power supply and spaced away from one another at a certain distance, and an insulated medium provided between the first and second electrodes. The second electrode is adapted to carry the piezoelectric ceramic which is spaced away from the first electrode. In this way, a piezoelectric ceramic can be poled by a poling field created between the first and second electrodes and prevented from being scraped by the first electrode or damaged by the ripples caused by an unstable voltage because of the separation of the piezoelectric ceramic to be poled from the first electrode and the buffering effect caused by the insulated medium between the first and second electrodes. In addition, the second electrode may be specifically in the form of a power-driven metal conveyor so that the piezoelectric ceramic to be poled can continuously pass through and be poled by the poling field.

Abstract: 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.

Abstract: Piezoelectric ceramic polymer matrices, piezoelectric composites, and methods of make the matrices and composites are disclosed.

Abstract: A strain gage comprising a strained-layer superlattice crystal exhibiting piezoelectric properties is described. A substrate upon which such a strained-layer superlattice crystal has been deposited is attached to an element to be monitored for strain. A light source is focused on the superlattice crystal and the light reflected from, passed through, or emitted from the crystal is gathered and compared with previously obtained optical property data to determine the strain in the element.

Abstract: Disclosed are new piezoelectric/pyroelectric materials of polarized homopolymer and copolymers of trifluorovinyl acetate. Also disclosed is a unique predictive relationship for determining the piezoelectricity of unknown material.

Abstract: Laminates of polyvinylidene fluroride (PVDF) are employed as piezoelectric sensors and actuators which can sense and/or generate complex motions that include bending, stretching, and twisting components. The laminates can be attached directly to a mechanical structure whose motions are to be sensed and/or controlled. By skewing the principal axes of each of the lamina in the laminate with respect to one another, the laminate is responsive not only to bending motions, but to torsional motions as well. Surface electrodes are disposed on the top and bottom sides of each of the lamina to either sense voltage generated by the lamina in response to motion imparted thereto, or supply voltage to the lamina to induce motion therein. The shape of the surface electrode patterns can be varied to control the particular components of motion to which each of the lamina is responsive (e.g., bending modes). The polarization profile in each of the lamina can also be varied for this purpose.

Abstract: A movable member of a vibration wave motor is driven by a twist component of an off-plane travelling vibration wave generated by a vibration member in a resonance vibration mode.

Abstract: An ultrasonic vibrator comprises torsional electrostrictive transducers for torsional vibration, longitudinal electrostrictive transducers for longitudinal vibration, and two metallic members firmly, coaxially and integrally holding the torsional electrostrictive transducers and the longitudinal electrostrictive transducers therebetween. An altered section is formed in one of the metallic members in such a shape that makes the torsional resonant frequency and the longitudinal resonant frequency coincide with each other. A voltage or an electric current having a controlled amplitude and/or a controlled relative phase is applied to the electrostrictive transducers to generate composite vibrations of various modes.

Abstract: A polymer piezoelectric film comprising a poled film of a vinylidene fluoride copolymer having a high molecular weight as defined by an inherent viscosity within a specific range comprising 40 to 90 mol. % of vinylidene fluoride and 10 to 60 mol. % of trifluoroethylene. Such a high molecular weight vinylidene fluoride copolymer can give a preferable state of molecular arrangement during film formation, particularly preferably formation by casting, to provide a film excellent in piezoelectric characteristic and secondary processing characteristic.

Abstract: An input device such as a keyboard or a tablet for input of pattern employing a piezoelectric material/polymer 1-3 composite of the structure in which a number of rods of piezoelectric material are buried in a polymer.

Abstract: The invention relates to a multi-layered piezoelectric acoustic transducer for generating layers of the same piezoelectric material are provided such tool alternate layers have different crystallographic orientations and different piezoelectric coupling coefficients. The layers may be provided so that alternate layers have crystallographic orientations which provide maximum electro-acoustic coupling and layers which provide minimum electro-acoustic coupling.

Abstract: The invention concerns an ultrasonic sensor (24) in which a polymer foil (4) supported in its peripheral area is piezoelectrically activated at least in a partial section (42). The partial section (42) is electrically coupled to electrodes (8). According to the invention, the electrodes (8), which produce an electrical signal in cooperation with this partial section (42) in response to an ultrasonic wave and are spatially separated from the piezoelectrically active section (42). Because of this feature, the ultrasonic sensor (24) can be used also for measuring ultrasonic shock waves with a high pressure amplitude, since an electrically conductive layer for receiving the electrical signal located on the flat sides of the polymer foil (4) in the piezoelectrically active section (42), is no longer needed.

Abstract: A composite of PZT (lead zirconate titanate) and a compliant polymer having 1-3-0 connectivity is described. A polymer self-connected in all three mutually perpendicular directions with a void in the center has an array of parallel PZT rod elements embedded therein and extending through the void. The void isolates a region of the PZT rods from the polymer. The axes of the PZT rods are along the direction of the poling electric field. Such an arrangement significantly enhances the hydrostatic piezoelectric charge and voltage coefficients d.sub.h and g.sub.h.

Abstract: A low aging piezoelectric resonator is made from a plate of piezoelectric terial using standard resonator fabrication techniques with identical electrodes applied to both major faces of the plate; the electroded plate mounted in a suitable enclosure and the unit vacuum baked and sealed under high vacuum to remove as much contamination as possible, and a DC voltage impressed between the resonator electrodes and the enclosure to create a static electric filed within the enclosure.

Abstract: A piezoelectric vibrator comprises a mechanical vibrating member having, an aluminum layer formed on a surface of the vibrating member, and a piezoelectric transducer overlaying the aluminum layer.

Abstract: A piezoelectric device comprising a first conductor, a conductive polymer member which contacts the first conductor, a piezoelectric polymer member which contacts the conductive polymer member but which is separated from the first conductor and which has been rendered piezoelectric by stretching and polarizing it while it is in contact with the conductive polymer member, and a second conductor which contacts the piezoelectric polymer member but which is separated from both the conductive polymer and the first conductor.

Abstract: Means for polarizing ferroelectric materials up to a predetermined polarization level include the application of an electric field E to these materials. According to this method the ferroelectric material is subjected to an alternating electric field E, the frequency of which ranges from about 0.001 to 1 Hz, and which is made to increase gradually and in a cyclic way between 0.+-.E.sub.N, E.sub.N being slightly in excess of the coercive force E.sub.C of said material. Simultaneously, the intensity i of the current traversing the material (2) is measured as a function of the applied field (E) using a unit of visualization, until a stable curve i=f(E) is attained. The invention is particularly suitable for obtaining a stable polarization of ferroelectric polymers, copolymers, crystals, and polycrystals, with the objective of using the piezoelectric and/or pyroelectric properties of these materials.

Abstract: A ultrasonic transducer using such a piezoelectric composite that a number of piezoelectric poles made of piezoelectric ceramics are arranged in a plate-like polymer matrix perpendicular to the plate surface. The volume ratio of the piezoelectric poles is set in a range of 0.15-0.75 and a spacing between every adjacent piezoelectric poles is set smaller than the thickness of the polymer plate, thereby resulting in a transducer which has higher sensitivity than the conventional one using a homogeneous piezoelectric ceramic plate.

Abstract: An ultrasonic transducer using a piezoelectric composite in which a plurality of piezoelectric poles are arranged in matrix maintaining a gap and a polymer is charged into the gap. The piezoelectric poles are arranged maintaining a pitch which is shorter than a wavelength of a sound wave at a fundamental resonance frequency of the transducer in a medium. Further the pitch may be changed in a direction in which the piezoelectric poles are arranged, in order to restrain the grating lobe from generating.

Abstract: A piezoelectric transducer including a polarized piezoelectric material film, which also has a reinforcing material incorporated into the mass and which prevents any deformation of the film in certain given directions.The invention also relates to a pressure sensor using such a transducer.This sensor can be used both as a pressure sensor and as a pressure gradient measuring device.

Abstract: A piezoelectric coaxial cable comprises a central stretchable electrical conductor (1), preferably formed from a low melting point metal alloy, a piezoelectric intermediate layer (2), preferably formed from a vinylidene fluoride polymer which has been stretched and radially polarized to render it piezoelectric, and an outer electrical conductor (3).The intermediate layer has a ratio R of its internal radius to its external radius which is preferably not more than 0.5 and especially not more than 0.4. This construction enables coaxial cables to be formed without voiding or breaking of the internal conductor during stretching.

Abstract: A 3-terminal oscillating element has a square plate-like piezoelectric body, first and second electrodes provided on one surface of the piezoelectric body and a common electrode provided on the other surface of the piezoelectric body. The piezoelectric body is polarized in one direction between the first and common electrodes and in the opposite direction between the second and common electrode. The 3-terminal oscillating element, when provided in place of a combination of 2-terminal oscillating element and two externally provided capacitors C.sub.1 and C.sub.2 in a Colpitts circuit, substantially satisfies the following equations: ##EQU1## wherein C.sub.01 is an electrostatic capacitance between the first electrode and the counter electrode, C.sub.02 is an electrostatic capacitance between the second electrode and the counter electrode, and n is an transformation ratio of an ideal transformer; and ##EQU2## wherein S.sub.1 and S.sub.2 are areas of first and second electrodes, respectively.

Abstract: A piezoelectric coaxial cable comprises a conductive polymer core comprising a high molecular weight polymeric material having conductive particles dispersed therein, a piezoelectric polymer layer surrounding the conductive polymer core, and an outer conductor surrounding the piezoelectric polymer layer. The high molecular weight polymeric material of the conductive polymer core comprises a polymer capable of being intimately bonded to the piezoelectric polymer.

Abstract: A piezoelectric resonator utilizing the longitudinal vibration mode of piezoelectric ceramics. Exciting electrodes are formed on the lengthwise opposite end surface of the piezoelectric ceramic. Lengthwise extending surfaces of the piezoelectric ceramic are formed with insulating layers. A pair of take-out electrodes are provided which cover the insulating layers and which are connected to the exciting electrodes.

Abstract: A simplified method for fabricating composite transducers by bonding together plates of active and passive materials to form a laminated block. The active material is preferably a piezoelectric ceramic. Thereafter, a series of cuts are made in the laminated block to obtain a composite plate wherein regions of active material are separated from one another by regions of passive material. The method provides composite transducers having fine structures which can be produced without the difficulty of assembling many small rods or sawing deep, narrow grooves.

Abstract: A process for preparing a polymeric piezoelectric material which comprises a vinylidene fluoride containing polymer, comprising applying at least two cycles of alternate electric field except a rectangular wave to the material to polarize it, by which process, the polymeric piezoelectric material is prepared at a low temperature for a short time.

Abstract: Disclosed is a polarized, shaped material comprising a copolymer of 40 to 87 mol % of vinylidene fluoride, 10 to 40 mol % of trifluoroethylene and 3 to 20 mol % of vinyl fluoride.

Abstract: An ultrasound transducer for medical pulse echo applications is apodized by causing the level of response to vary as a function of position on the transducer aperture. In a preferred embodiment, the response varies as a Gaussian function of distance from the center or centerline of the transducer so that the response at the edge of the transducer is approximately 30% of the response at the center or centerline. The response may be varied by causing the polarization of a piezoelectric ceramic transducer to decrease as a function of distance from the acoustic axis. In a preferred embodiment the transducer comprises a matrix of parallel rods of piezoelectric ceramic in an inert binder. The polarization of the piezoelectric body may be controlled by locally polarizing regions of the transducer with different voltages or for different periods of time. A polarization profile may also be produced by selectively heating localized regions of a previously uniformly polarized transducer to selectively depolarize them.

Abstract: Problems of resolution and focussing arise in the near field in systems employing radiation, including ultrasonic systems. These problems can be alleviated by suppressing the plane waves in the combination of plane waves and edge waves usually employed. Several ultrasonic transducers with this property are described and in one a piezoelectric disc with surface electrodes is non-linearly polarized to transmit edge waves without plane waves.

Abstract: A piezoelectric printer including: a frame; a plurality of printer units mounted on the frame; each unit including an asymmetric piezoelectric bender including one or more piezoelectric members and having a mounting portion and an actuating portion, the actuating portion being moveable in an actuating direction; the bender being tapered in its lateral dimension and being larger at the mounting portion and smaller at the actuating portion; first and second metal reinforcing layers externally mounted on said bender, the first on the side of the actuating direction, the second on the opposite side; and a printing element driven by the actuating portion; means for applying an actuating voltage to the bender in the poling direction for actuating the bender to drive the printing element to the printing position and guide means attached to the frame for guiding the printing elements; the printer units are arranged in sets of stacked arrays, which may be overlapped and may include holes in each of the inferior printe

Abstract: A composite of PZT (Lead Zirconate Titanate) and a compliant polymer matrix aving 3-1 connectivity (i.e., in a diphasic material, one of the two phases is continuously self-connected in all three mutually perpendicular directions and the second phase is self-connected only along one of the three mutually perpendicular directions) and fabrication method thereof is described. An array of parallel PZT rod elements is embedded in a mechanically compliant polymer matrix with their axes along the direction of the poling electric field. Such a composite has a high value of g.sub.h, d.sub.h and g.sub.33 with very little sacrifice in the value of d.sub.33.

Abstract: A method of making flexible composite piezoelectric materials exhibiting hydrostatic response and having a stable response over time is given. A prepolymer material is combined with a piezoelectric material and polarized by applying an electric field while inducing an electric dipole in the piezoelectric material, typically by applying hydrostatic pressure or changing the temperature. To ensure stable response characteristics, the polymer material is chosen to have a shear modulus of less than 20 pounds per square inch. To help ensure good contact between the piezoelectric material and the polymer material, controlled shrinkage may be induced in the composite materials by heat or the removal of a volatile material. The prepolymer material desirably has an electrical resistivity greater than 10.sup.10 ohm/meters. Typical piezoelectric materials include lithium sulfate and tartaric acid. Typical polymer materials include RTV rubber, urethanes, and polybutadienes, and may be in the form of oligomers.

Abstract: The invention relates to the manufacture of electromechanical transducers with at least one element made from a polymer material shaped and polarized so as to obtain an active self-supporting structure having a nondevelopable surface and to a manufacturing process which consists in shaping a structure already coated with metalizations, so that the electric polarizing field may be applied to the structure during shaping and until return thereof to ambient temperature.

Abstract: An ink jet comprises an elastic tubular member (14) characterized by piezoelectric properties. The tubular member (14) is terminated in an orifice (26) adapted to pass droplets of ink when the chamber formed within the tubular member (14) is reduced in size. The piezoelectric properties are provided by a substantially homogeneous mixture of piezoelectric material and an elastic binder.

Abstract: A pickup for an electric string type instrument comprising an elongated piezo-electric member formed by mixing a high molecular material with piezo-electric ceramic powder and a vulcanizing or cross-linking agent and then vulcanizing or cross-linking the mixture. In order to complete the pickup a pair of electrodes are mounted on the elongated member and the member is then subjected to a polarization treatment. The piezo-electric member can be formed as a flat belt-shaped member with the electrodes mounted on both surfaces thereof or it can be formed as a cylinder in which one of the electrodes extends axially in the piezo-electric member and the other electrode is mounted on the outer periphery of the piezo-electric member. A plurality of the pickups can be joined in parallel relation within an elastic support and the latter can be mounted between the strings and the frame of the string instrument through the intermediary of a bridge member.

Abstract: A body of polymeric piezoelectric material is nonuniformly poled by establishing a temperature gradient greater than about 10.degree. C. and less than about 100.degree. C. across the thickness of the body and applying an electric field across the thickness of the body in an amount and for a time sufficient to induce nonuniform polarization in the material, whereby a portion of the body near the surface maintained at a lower temperature receives relatively stronger polarization than a portion near the surface maintained at a higher temperature.In a preferred embodiment of the invention, after poling in one direction in a temperature gradient to more strongly polarize a portion of the material near one surface, the temperature gradient and the field polarity are reversed, to polarize a portion of the body near the opposite surface in an opposite direction.