Abstract: A piezoelectric resonator having a small spurious resonance and a large difference .increment.F between the resonant frequency and the antiresonant frequency is constructed that a resonant frequency or antiresonant frequency can be easily and accurately adjusted to a low frequency. The piezoelectric resonator has a base member which includes a plurality of laminated piezoelectric layers and a plurality of inner electrodes disposed substantially perpendicularly to the longitudinal direction of the base member. The plurality of piezoelectric layers are polarized in the longitudinal direction of the base member. A first external electrode and a second external electrode are located on a surface of the base member and connected to the plurality of electrodes. The resonant frequency of the piezoelectric resonator is adjusted by cutting an intermediate portion in the longitudinal direction of the base member.

Abstract: Piezoelectric resonators utilizing a differentially offset reflector. One or more piezoelectric resonators are supported upon a substrate by one or more intervening layers of material, which intervening layers of material act as a reflector. The reflector isolates the resonators from the substrate. A portion of one or more of the intervening layers of material includes a differential layer of material, which differential layer shifts the resonant frequencies of the resonators that overlie the differential layer as compared with the resonant frequencies of those resonators that do not overlie the differential layer of material.

Abstract: A serpentine cross-section piezoelectric linear actuator includes a unitary, densified, rigid, monolithic piezoelectric or electrostrictive ceramic body, the body including a top, four sides generally normal to and interconnected with the top, a base generally normal to and interconnected with the sides, and two or more ceramic layers including a top ceramic layer providing the top, a bottom ceramic layer providing the bottom, and, optionally, one or more intermediate ceramic layers, the layers being disposed parallel to and superimposed over one another. Each ceramic layer except the top ceramic layer is joined at a first side to one of the ceramic layers adjacent thereto by a first ceramic bridge and each ceramic layer except the bottom ceramic layer is joined at a second side opposite the first side to another of the ceramic layers adjacent thereto by a second ceramic bridge.

Abstract: A shape formed multi-laminate transducer which conforms to nonlinear dependent shaped geometries and the shape forming process for producing the nonlinear dependent shaped multilaminate transducer is presented. The shape forming process includes the cutting of the tape cast material to a predetermined two-dimensional shape and then pressing the cut material to form the desired three-dimensional nonlinear dependent shape. After shape forming, the sample is sintered, metalized, poled, and made into an acoustical device such as a transducer. The production of such a device by using tape cast material allows designers to easily vary the shape of the product as well as to be able to vary the properties within simply by exploiting the lamination method associated with tape casting. As such, a designer is able to design and manufacture a transducer optimized to meet the requirements of a particular application.

Abstract: An improved ultrasound transceiver array for permitting improved imaging is taught. The array may be either a two dimensional array for volumetric imaging or a one dimensional array of elements shaped to permit a more precise beam focus for finer resolution imaging. An Nd:YAG laser is used to machine a workpiece from both ends to produce kerfs which taper inwardly from the transceiving side of the array thereby permitting a stronger ultrasound signal and clearer imaging.

Abstract: A piezoelectric vibration device is constructed to suppress interference between resonance sections and achieve a satisfactory resonance characteristic and sufficient mechanical strength. In the piezoelectric vibration device, a plurality of resonance sections are provided on a piezoelectric substrate and a slit is provided so as to extend from one side of the piezoelectric substrate toward a center thereof in order to suppress interference between the resonance sections. If the length of the slit is denoted as a, the gap width along the opposing direction of the first and second resonance electrodes in the resonance section as g, the distance from the center of the gap to the nearest side of the piezoelectric substrate and the sides of the slit as L.sub.1, and the external dimension of the piezoelectric substrate along one direction as L, then the expression L.sub.1 -g/2=b, b<a.ltoreq.(3/4)L is satisfied.

Abstract: A rotary actuator for applying torque to a crank with respect to a member. The rotary actuator has a substantially planar sheet of anisotropic conducting polymer, portions of which are activated in temporal sequence to produce rotation of the crank with respect to the axis of the crank. Actuation is achieved by contraction of successive portions of the sheet as electrical current causes differential strain in the sheet.

Abstract: A piezo-electric resonator includes terminal plates holding a piezo-electric substrate and which are stored in a case. The piezo-electric substrate can be formed from piezo-electric ceramics. The piezo-electric ceramic plate has projections at the non-vibrating sections of its cuter circumferential side surfaces. When the centers of the piezo-electric ceramic plate are held by the terminal plates, the projections do not contact the inner surfaces of the case. When the position of the piezo-electric ceramic plate is displaced due to external vibration, the projections may contact the inner surfaces of the case and the vibrating sections of the piezo-electric ceramic plate do not contact the inner surfaces of the case. Due to this fact, its electrical characteristics are not changed. in addition, since this configuration is set such that the piezo-electric ceramic plate can be slightly moved in the case, the piezo-electric ceramic plate is less likely to receive a high shock or stress through the case.

Abstract: A wideband ultrasound transducer having a plurality of transducer elements sequentially arranged in an azimuth direction. Each transducer element is spaced from adjacent transducer elements in the azimuth direction and each transducer element extends from a first end to a second end in an elevation direction. Each transducer element has a thickness in a range direction that increases from the first end to the second end wherein each transducer element is thinnest at the first end and thickest at the second end. The spacing of the transducer elements increases from the first end to the second end so that the spacing is at a minimum at the first end and a maximum at the second end.

Abstract: This invention relates to a new class of piezoelectric composites with a radial design. More particularly, the radial design of these new ceramic/polymer composites show a higher sensitivity in the radial direction than conventional tube structured devices. Devices made utilizing this novel design will therefore show significantly enhanced performance in many applications.

Abstract: A vibrator comprising a base part at least one of whose ends is fixed, a first leg extending in a direction crossing this base part, a second leg extending in a direction crossing the base part and being opposed to said first leg with respect to said base part, a first bending-vibration piece extending in a direction crossing said first leg, a second bending-vibration piece extending in a direction crossing the first leg and being opposite to said first bending-vibration piece with respect to said first leg, a third bending-vibration piece extending in a direction crossing said second leg, and a fourth bending-vibration piece extending in a direction crossing the second leg and being opposite to said third bending-vibration piece with respect to said second leg.

Abstract: A backing block for an ultrasonic array transducer comprises a flex circuit embedded in a body of acoustic backing material, with conductive traces on the flex circuit terminating at the surface of the body at which an array transducer is mounted and extending out from the rear of the body for connection to electrical circuitry. The array transducer is formed of a composite material in which the pattern of the composite material is oriented at an oblique angle to the kerfs of the transducer.

Abstract: A quartz crystal element in which unwanted response is suppressed, comprising a thickness shear quartz blank such as an AT-cut type. An area where an amplitude of unwanted response may be strong can be eliminated from the quartz blank by forming the quartz blank into a substantially hexagon. Preferably, each pair of three pairs of opposite sides are mutually parallel and one of the pairs is parallel to the longest diagonal line of the quartz blank. For an AT-cut type of quartz crystal element, the direction of the longest diagonal line of the quartz blank is within the range of 28.degree..+-.15.degree. or 118.degree..+-.15.degree. from the Z' axis direction of the quartz blank, and the quartz blank is held at the ends of the longest diagonal line.

Abstract: A vibrating gyroscope includes: a column-shaped vibrating body; driving elements formed on side-faces of the vibrating body, for exciting a bending vibration in the vibrating body; detection elements formed on side-faces of the vibrating body, for detecting changes in the bending vibration of the vibrating body; pseudo-Coriolis force generating elements formed on side-faces of the vibrating body, for applying a force to the vibrating body in the same direction as that of a Coriolis force generated when a rotational angular velocity is produced about the vibrating body; and a pseudo-Coriolis signal generating circuit for supplying the pseudo-Coriolis force generating elements with a pseudo-Coriolis signal to apply a force in the same direction as that of the Coriolis force to the vibrating body.

Abstract: A vibrator of a vibratory gyroscope comprises a main arm having a base part and at least one bending-vibration piece extending from the base part in a direction crossing the longitudinal direction of the base part and a fixing part for fixing one end of the base part, and the base part and the bending-vibration piece are formed so as to extend substantially in a specified plane. Preferably, at the opposite side to one end of the base part, a projection projecting from the bending-vibration piece is provided, or at least a pair of resonant arms resonating with vibration of the base part, said pair of resonant arms projecting from the fixing part are provided. Thanks to this, it has been possible to detect a turning angular rate in a sufficiently high accuracy without providing a projection which has a certain weight and extends from the vibrator toward the axis of turning even in case of arranging the vibrator so that the vibration arm of the vibrator extends perpendicularly to the axis of turning.

Abstract: A resonator having piezoelectric properties is tuned to respond at a specific overtone of its parallel plate resonant frequency. A channel is etched in a blank to confine the oscillations to a predefined area thereby maximizing a predetermined overtone. The position and dimension of the channel are selected to confine the oscillation to a radius that maximizes the response at a desired frequency. The desired frequency is a predetermined overtone of the fundamental frequency. The channel limits the area of oscillation of the blank. The channel may be formed using grooves or slots. The slots are arranged to form a ring. The channel may be positioned inside or outside an electrode.

Abstract: A piezoelectric component prevents development of a short circuit between separate electrodes of a piezoelectric element and provides a high level of connection reliability. The piezoelectric component includes a piezoelectric element utilizing a longitudinal oscillation mode and being mounted on a mounting substrate. The piezoelectric element has on one main surface thereof a first electrode and a second electrode formed by dividing electrode material via longitudinally extending linear grooves and, on the other main surface, a third electrode. Conductive support members are secured to node sections of the first and second electrodes so as to be spaced apart from each other with respect to the longitudinal dimension of the piezoelectric substrate. The support members are adhered to and secured to pattern electrodes of the mounting substrate by conductive adhesive.

Abstract: A vibrator of a vibratory gyroscope comprises a main arm having a base part and at least one bending-vibration piece extending from the base part in a direction crossing the longitudinal direction of the base part and a fixing part for fixing one end of the base part, and the base part and the bending-vibration piece are formed so as to extend substantially in a specified plane. Preferably, at the opposite side to one end of the base part, a projection projecting from the bending-vibration piece is provided, or at least a pair of resonant arms resonating with vibration of the base part, said pair of resonant arms projecting from the fixing part are provided. Thanks to this, it has been possible to detect a turning angular rate in a sufficiently high accuracy without providing a projection which has a certain weight and extends from the vibrator toward the axis of turning even in case of arranging the vibrator so that the vibration arm of the vibrator extends perpendicularly to the axis of turning.

Abstract: A three crystal ultrasound transducer in which each crystal has a thickness that is measured in the z-range direction that varies as a function of its position along the x-elevation direction. The impedance of the transducer is reduced compared with uniform thickness transducers thereby providing a better electrical match between the ultrasound transducer and the ultrasound system to which it is coupled.

Abstract: A vibrating gyroscope includes a ring-shaped vibrator having a node. A driver element is provided to cause the vibrator to vibrate flexurally. A detector element is formed along an axis of the vibrator and has a surface disposed such that the surface is non-perpendicular to a direction of vibration of said vibrator while the vibrator remains stationary. In one embodiment, the vibrator is metallic and the driver and detector are piezoelectric elements. In another embodiment, the vibrator is piezoelectric and the driver and detector are metal electrodes.

Abstract: A vibratory gyroscope including an elongated vibrator having a central (neutral) axis (Y-axis), a drive unit for deforming the first direction such that the vibrator vibrates in a first (X) direction, an added mass attached to the vibrator at a position offset from the central axis in a second (Z) direction, and a detector formed on the vibrator. Rotation of the vibratory gyroscope about the second (Z) direction during vibration in the second direction causes Coriolis force to acting on the added mass in a direction parallel to the central axis. Because the added mass is offset from the central axis, a resulting vibration in the second (Z) direction is produced, which is detected by the detector. With this arrangement, the central axis of the vibrator is placed in parallel with the surface of rotation of the rotating system. Thus, rotations about two or three axes in each direction can be detected in such a manner that noise generation is prevented.

Abstract: A piezoelectric resonator has a base member formed by laminating a plurality of piezoelectric layers and electrodes. The base member is polarized in different directions at both sides of each electrode. Electrodes are alternately covered by a first insulating film and a second insulating film, respectively, at both sides of a groove formed in the base member. The first insulating film covers electrodes which are not covered by the second insulating film, and vice versa. External electrodes are formed at both sides of the groove on the base member and the internal electrodes are connected to the external electrodes. A support member made from an electrically conductive material is provided at the approximate centers of the external electrodes.

Abstract: A vibrating gyroscope has a mounting substrate carrying a vibrator. The mounting substrate is supported and fixed by a plurality of connecting members at a level above a circuit board. The supporting members also provide electrical connection between a wiring on the mounting substrate and a circuitry including an oscillation circuit and a detection circuit on the circuit board. Each connecting member has one end fixed to a point on the mounting substrate substantially in the middle of the path of propagation of vibration which is between supporting pins and which detours around a slit formed in the mounting substrate.

Abstract: In a vibration gyroscope 1, a vibrator 2 is mounted to a mounting substrate 7 through support pins 6a and 6b. The mounting substrate 7 and a support substrate 10 are disposed opposite by inserting protrusions 11a and 11b of the support substrate 10 into second insertion holes 9a and 9b of the mounting substrate 7 and by supporting the mounting substrate 7 with convex molded sections 14a and 14b. The space between the substrates 7 and 10 are filled with elastic paste made up of synthetic resin such as urethan and silicone, or the like. The paste is dried to form a vibration absorbing member 13. Alternatively, the vibration absorbing member 13 is formed on the surface of a mounting substrate 22.

Abstract: An improved ultrasound transceiver array for permitting improved imaging is taught. The array may be either a two dimensional array for volumetric imaging or a one dimensional array of elements shaped to permit a more precise beam focus for finer resolution imaging. An Nd:YAG laser is used to machine a workpiece from both ends to produce kerfs which taper inwardly from the transceiving side of the array thereby permitting a stronger ultrasound signal and clearer imaging.

Abstract: Multiple piezoelectric ceramic filter elements have different center frequencies from each other and are cascade connected together. The piezoelectric ceramic filter elements satisfy the condition 0<.vertline.dF.sub.0 .vertline./BW.sub.3 <0.8; where .vertline.dF.sub.0 .vertline. is the absolute value of the frequency difference dF.sub.0 between the center frequencies, and BW.sub.3 is the band width of each piezoelectric ceramic filter element in which the amplitude loss is 3 dB or less. A low insertion loss and an improvement in the group delay characteristics are compatible at the same time.

Abstract: A vibration gyroscope 10 includes a vibrator 12. The vibrator 12 has a vibration member 14 formed in a regular triangular prism shape and piezoelectric elements 16a, 16b and 16c. Two of the piezoelectric elements 16a and 16b are polarized in the direction from the outside to the vibration member 14, and the other piezoelectric element 16c is polarized in the direction from the vibration member 14 to the outside. An oscillation circuit 28 sends signals to the piezoelectric elements 16a to 16c and a signal output from the vibration member 14 is fed back. Two of the piezoelectric elements 16a and 16b are connected to a differential circuit 30. The differential circuit 30 is connected to a synchronous detection circuit 32 and then connected to a smoothing circuit 34 and a DC amplifier 36 in series.

Abstract: An ink jet printing head that, based on the face shooter principle, contains a nozzle row arranged in the z-direction in the surface of a plate, allowing an ink jet to be ejected in the y-direction, a membrane plate arranged on a first chamber plate carrying the ink chambers, and paths for delivering and actuators for expelling ink from each chamber. The ink jet printing head also has a second chamber plate in a different level from the first chamber plate. The chambers of the second chamber plate are arranged offset in the x- and z-directions relative to the chambers of the first chamber plate. The overlap of chambers of neighboring levels becomes minimal as a result. After a pre-treatment of the plate material of which the printing head is constructed, a masking and etching of the plates ensues in a parallel plate processing for all individual parts. Separated, finished discrete parts are joined and contacted to form a module.

Abstract: A vibration gyroscope includes a cross-shaped vibration member having two axes perpendicular to each other, an excitation structure for generating a bending vibration such that vibrations along the two axes of the vibration member have opposite phases, and a detecting structure for detecting angular velocities around the two axes of the vibration member during excitation of the bending vibration on the basis of bending displacements.

Abstract: A transducer including a ceramic body having a base and an array of tube-shaped piezoelectric or electrostrictive ceramic elements integral with the base. A first electrode contacts the tube wall inner surface, while a second electrode contacts the tube wall outer surface and is electrically isolated from the first electrode and from the lower surface of the transducer. The first electrode extends onto the transducer lower surface for electrical connection to a power source for driving the transducer across the tube walls for d.sub.31 mode vibration of the tube walls. A stiff cover plate may be used to transmit the tube wall vibration to a desired medium. The ceramic base may be removed if an electrically insulating layer is provided between the elements at the lower surface of the transducer. The insulating layer and tube wall upper edges then electrically isolate the second electrode from the first electrode and the transducer lower surface.

Abstract: In a method and apparatus for producing an ink jet printer head composed of a number of stacked modules, a piezoactuator plate is formed by metallizing opposite major faces of a plate of piezoelectric material, while leaving an unmetallized stripe on one of said major faces, thereby separating the metallization on that major face into two regions. A side face of the piezoelectric plate is also metallized, the side face extending substantially parallel to the unmetallized stripe, thereby electrically connecting one of the metallized regions on one major face to the metallized layer on the opposite major face. The metallized piezoelectric plate is then structured so as to produce a number of side-by-side piezoactuators therein, each piezoactuator having first and second electrodes formed by the respective metallization on the opposite sides of the plate. Respective electrical leads for the two electrodes of each piezoactuator can be electrically contacted to the same side of the plate, i.e.

Abstract: A multi-segmented flextensional transducer includes a plurality of electroplated electroactive members which deform in concert when energized by an electrical field. Each electroactive member has a convex surface at one end and a concave surface at its opposite end. The electroactive members are arranged end-to-end such that the convex face of each intermediate electroactive member engages the concave face of an adjacent electroactive member, thus forming a cooperative array or "train" of electroactive members. The opposite ends of the train of -electroactive members is received by a frame which holds the end electroactive members in fixed relative position. The electroactive members are high deformation flextensional piezoelectric elements. When energized, each electroactive member individually deforms, and the entire array deforms in concert an amount significantly exceeding that of the individual electroactive members.

Abstract: An ultrasonic motor with a stator uniformly made of a material that can convert electrical energy to mechanical energy. The stator includes a first part having two corresponding electrodes for applying a signal to the first part, and a second part, uniformly configured to the first part, having an area adjacent to the first part where the material does not exist. The second part does not exist between the electrodes. A moving element is in contact with the second part and driven by progressive oscillation waves generated in the second part due to the signal applied to the electrodes.

Abstract: A piezoelectric resonator adapted for use in the band from several hundreds of kilohertz to 2 MHz utilizes a newly discovered width vibration mode and permits use of a simplified support structure which reduces stress on the resonator and reduces the overall size of the resonator. The resonator has a substantially rectangular cross-sectional shape having a pair of shorter sides and a pair of longer sides. To achieve the newly discovered vibration mode, the ratio of the length b of the longer sides to the length a of the shorter sides is set to be within +10% of a value given byb/a=n(-2.70.sigma.+2.86)where n is an integer and .sigma. is the Poisson's ratio of the ymaterial used to form the resonator.

Abstract: A vibratory gyroscope including an elongated vibrator having a central (neutral) axis (Y-axis), a drive unit for deforming the first direction such that the vibrator vibrates in a first (X) direction, an added mass attached to the vibrator at a position offset from the central axis in a second (Z) direction, and a detector formed on the vibrator. Rotation of the vibratory gyroscope about the second (Z) direction during vibration in the second direction causes Coriolis force to acting on the added mass in a direction parallel to the central axis. Because the added mass is offset from the central axis, a resulting vibration in the second (Z) direction is produced, which is detected by the detector. With this arrangement, the central axis of the vibrator is placed in parallel with the surface of rotation of the rotating system. Thus, rotations about two or three axes in each direction can be detected in such a manner that noise generation is prevented.

Abstract: A chemical sensor for measuring a change in the sensor mass relating to the interaction of a surface of the sensor with a solution comprises a crystal detector oscillator capable of providing a measurement signal based upon the resonant frequency of the crystal detector oscillator. The crystal detector oscillator has a first crystal side for directly contacting the solution, and a second crystal side isolated from contacting the solution. A first electrode is integral to the first crystal side, with the first electrode having an inner and outer perimeter defining an outer portion of the first crystal side which is exterior to the outer perimeter of the first electrode and an inner portion of the first crystal side which is interior to the inner perimeter of the first electrode. A second electrode is integral to the second crystal side.

Abstract: A chip-type piezoelectric resonance component is prepared by bonding spacer plates to side portions of an energy trap piezoelectric resonator. The resonator includes a piezoelectric resonance unit coupled with dynamic dampers vibrating for suppressing vibration as it is propagated, with the vibration being suppressed through a phenomenon of the dynamic dampers. Case members are pasted onto upper and lower portions of an element plate through sheet-type adhesives which define spaces for allowing vibration and prevent vibration of the vibrating portions from being hindered.

Abstract: A bone inducing material comprising a piezoelectric porous membrane having through-holes of an average pore size of about 0.1 to 5 .mu.m is disclosed. When the bone inducing material according to the present invention is used, bone is rapidly regenerated, and new formation of bone occurs. The bone inducing material is particularly useful in the dental field, for example, for treatment of periodontal diseases by GTR method.

Abstract: A piezoelectric ceramic linear actuator utilizing a piezoelectric characteristic which can be voluminously produced at a low cost. An electrode 104 is disposed on a ceramic green sheet 102 which is changeable in shape, constituting and electro-mechanical transducer element. A part of this piezoelectric ceramic green sheet 102 is fixed on a fixing base 106 (in the example given in FIG. 2, fixed on the left surface of a projection 108 of the fixing base 106), and the repetitive extension and contraction of a non-stationary part drives an article to be carried 110. In the example of FIG. 2, a wiring is installed so that there can be formed a first condition in which a C part contracts with the extension of an A part and at the same time a D part contracts with the extension of a B part, and a second condition in which the C part extends with the contraction of the A part and at the same time the D part extends with the contraction of the B part.

Abstract: Disclosed herein is a vibrating unit comprising vibration cancel means which is coupled to a vibration source through a vibration transfer part. The vibration cancel means receives vibration from the vibration source and resonates in a bending mode, to cancel vibration as propagated by a dynamic vibration absorbing phenomenon.

Abstract: An actuator for tilting the plane of an object includes a substrate and a pair of piezoelectric material members. Each of the piezoelectric members has a top surface, a bottom surface, a first side surface and a second side surface. The bottom surface is mounted to the substrate, and the first side surfaces of each of the members are affixed to each other and electrically connected in common. One of the piezoelectric material members further has a polarization selected so that a voltage applied between the first side surface and the second side surface thereof causes the piezoelectric material member to either contract or expand between the top surface and said bottom surface, depending on the polarity of the voltage. The object is mounted to the top surface of each of the piezoelectric material members so that when a voltage is applied to one of the piezoelectric material members, the object either tilts toward or away from that member, depending on the polarity of the voltage.

Abstract: A flextensional cover plate for redirecting the vibrational displacement of terminal ends of at least one pair of piezoelectric or electrostrictive ceramic bender elements vibrating toward and away from each other. The flextensional cover plate includes at least one flexible pleat configured to be bondable to terminal ends of the bender elements such that the bender element vibrational displacement is converted to vibrational displacement of said cover plate in a direction normal to said element vibrational displacement. The preferred flextensional cover plate is configured such that the amplitude of the cover plate vibrational displacement is greater than that of the bender element vibrational displacement.

Abstract: A piezoelectric device includes a ceramic substrate having at least one cavity defined by a thin-walled region of the substrate. The thin-walled region has an outer surface provided with at least one piezoelectric transducer and also with a non-operative portion situated adjacent to the piezoelectric transducer such that each piezoelectric transducer surrounds the non-operative portion, or two piezoelectric transducers are arranged on both sides of the non-operative portion.

Abstract: A piezoelectric oscillator comprises a piezoelectric oscillating reed, an insulating substrate for retaining the piezoelectric oscillating reed, and a cap fixed onto the top surface of the insulating substrate for enclosing the piezoelectric oscillating reed. Four connecting electrodes are formed on the top surface of the insulating substrate for electrical connection to the oscillating reed, which are divided into two groups. Each group includes two connecting electrodes which are connected to each other by metal interconnects. The insulating substrate is rectangular, and two connecting electrodes, each of which belong to one group, are located along the shorter sides of the insulating substrate. On the bottom surface of the insulating substrate, at least two external electrodes are formed, to which metal interconnects for each group are connected through the side surface of the insulating substrate.

Abstract: Combinations of oppositely poled piezoelectric shapes which, when electrically stimulated, effect increased linear or rotational displacement. In a typical arrangement a length of PVDF piezoelectric material poled in one direction is spatially separated from a second similarly shaped length of PVDF piezoelectric material poled in the opposite direction by an electrically inert substance. When stimulated by an appropriate voltage, one length contracts while the other length expands producing an increased deflection in the combination.

Abstract: Disposed within a float on the surface of a body of water is a vertically suspended, resilient piezoelectric element provided with a preselected strain by a hanging weight. The piezoelectric system functions as a weighted coiled spring which is driven into oscillation in response to movements of the float in response to passing surface waves. Preferably, the natural frequency of the system is selected in correspondence with the frequency of the passing waves for causing the system to oscillate in resonance with the passing waves. Additionally, a mechanism is provided for automatically adjusting the natural frequency of the system in response to changing wave conditions for maintaining the system in resonance with the waves.

Abstract: A torsional actuator consisting of multilayers of monolithic piezo-electric ceramic material, with planar electrodes between the successive layers and external contacts for supplying control voltages to the electrodes which cause the actuator to twist about its longitudinal axis by a torsion angle dependent on the control voltages. Viewed in cross-section, and with respect to a reference potential supplied to alternate ones of the electrodes, the remaining electrodes are in four respective quadrants and are supplied with control voltages of polarities dependent on the quadrants in which they are located.

Abstract: A method of manufacturing an electronic part includes a step of preparing a molten resin bathtub used for coating the outer surface of the electronic part. On a surface of the resin in the molten resin bathtub, a layer of a surface-active agent is formed. The electronic part body is dipped via the solvent layer into the molten resin bathtub. After coating the electronic part body with the molten resin, the electronic part body is removed from the molten resin bathtub. The molten resin is cured by heating and the resin layer is formed on the electronic part body.

Abstract: Disclosed herein is a piezoelectric resonator (11) utilizing a width expansion mode provided with a piezoelectric resonance part (12) having a rectangular section in which a ratio b/a of the length of each longer side to that of each shorter side is within a range of .+-.10% about the following value:b/a=n(-1.47.sigma.+1.88) (1)where a represents the length of each shorter side, b represents that of each longer side, .sigma. represents a Poisson's ratio and n represents an integer, and support members (16, 17) which are coupled to central portions of both shorter sides of the piezoelectric resonance part.

Abstract: In a chip-type piezoelectric resonance component, a piezo-resonator (3) is fixed onto a base substrate (2) and a cap member (4) is fixed to the base substrate (2) to enclose the piezo-resonator (3). The piezo-resonator (3) is provided with upper and lower surfaces having shorter and longer sides of lengths a and b at a ratio which is set in the range of .+-.10% about a value satisfying the following equation:b/a=n(-1.47.sigma.+1.88) (1)(n: integer)assuming that .sigma. represents the Poisson's ratio of a piezoelectric material.