Abstract: The present invention relates to a low-cost, disposable, flexure sensor with an active portion which includes first and second sensor elements formed from a piezoelectric polymer material. Each of the first and second sensor elements has a first surface and an opposed second surface. A first electrically conductive area is formed on the first surface of each sensor element and is connected to a second electrically conductive area on the second surface. In a preferred embodiment of the present invention, the electrical connection is formed by a plated hole which extends through the sensor element from the first surface to the second surface. Still further, each of the first and second sensor elements has a third electrically conductive area on the first surface, which electrically conductive area is electrically isolated from the first electrically conductive area.

Abstract: In a piezoelectric resonator 11 in which resonance electrodes 13 and 14 are formed on both major surfaces of a rectangular plane piezoelectric plate 12 and which utilizes stretching vibration along the short side of the piezoelectric plate 12, notches 15 and 16 are partially formed on the long sides of the piezoelectric plate 12, respectively in order to increase the resonance frequency.

Abstract: A ladder-type filter having a circuit structure obtained by connecting a plurality of series resonators and a plurality of parallel resonators with each other. At least one plate type series resonator and at least one plate type parallel resonator are stacked with each other. At least one of the series and parallel resonators is an energy trap type piezo-resonator having a plate type piezoelectric vibrating part, a support part which is coupled to the piezoelectric vibrating part, and a holding part which is coupled to the support part.

Abstract: A ladder-type filter having a circuit structure obtained by connecting a plurality of series resonators and a plurality of parallel resonators with each other. At least two plate-type resonators are laterally coupled with each other with respect to a mounting surface. At least one of the series and parallel resonators is an energy trap type piezo-resonator having a plate type piezoelectric vibrating part, a support part which is coupled to the piezoelectric vibrating part, and a holding part which is coupled to the support part.

Abstract: A ladder-type filter having a circuit structure obtained by connecting a plurality of series resonators and a plurality of parallel resonators with each other. At least two plate-type resonators are laterally coupled with each other with respect to a mounting surface. At least one of the series and parallel resonators is an energy trap type piezo-resonator having a plate type piezoelectric vibrating part, a support part which is coupled to the piezoelectric vibrating part, and a holding part which is coupled to the support part.

Abstract: A ladder-type filter having a circuit structure obtained by connecting a plurality of series resonators and a plurality of parallel resonators with each other. At least one plate type series resonator and at least one plate type parallel resonator are stacked with each other. At least one of the series and parallel resonators is an energy trap type piezo-resonator having a plate type piezoelectric vibrating part, a support part which is coupled to the piezoelectric vibrating part, and a holding part which is coupled to the support part.

Abstract: A ladder-type filter having a circuit structure obtained by connecting a plurality of series resonators and a plurality of parallel resonators with each other. At least one plate type series resonator and at least one plate type parallel resonator are stacked with each other. At least one of the series and parallel resonators is an energy trap type piezo-resonator having a plate type piezoelectric vibrating part, a support part which is coupled to the piezoelectric vibrating part, and a holding part which is coupled to the support part.

Abstract: An outer rear view mirror for a vehicle includes a casing for being connected to a side portion of the vehicle, a mirror member having an outer surface and accommodated within the casing such that the outer surface extends substantially perpendicular to a road surface, and a generator positioned at an upper portion of the outer surface of the mirror member and generating surface acoustic waves which travel along the outer surface of the mirror member towards a lower portion thereof. Water drops on the outer surface of the mirror member are expected to be urged to the lower portion of the mirror member, which results in that the resultant water drops are expelled by the gravity. Thus, the water drops can be removed from the outer surface of the mirror member.

Abstract: A ladder-type filter having a circuit structure obtained by connecting a plurality of series resonators and a plurality of parallel resonators with each other. At least two plate-type resonators are laterally coupled with each other with respect to a mounting surface. At least one of the series and parallel resonators is an energy trap type piezo-resonator having a plate type piezoelectric vibrating part, a support part which is coupled to the piezoelectric vibrating part, and a holding part which is coupled to the support part.

Abstract: An opening is formed in a region of a circuit board opposite a vibration region E of a piezoelectric element. The piezoelectric element is mounted to the circuit board, and electrical connections extend between and support the piezoelectric element from the circuit board by a solder. The soldered connection portions are surrounded by a bonding agent. An opening in the circuit board prevents any excess bonding agent from invading the vibration region E of the piezoelectric element, and the bonding agent assists in dispersing stresses exerted on the circuit board thereby minimizing the stresses transferred to the piezoelectric element.

Abstract: A piezoelectric device includes a piezoelectric plate provided with at least one electrode at almost a central portion of each face; a first plate made of an ionic material having a recessed portion to cover the at least one electrode at one face to face the piezoelectric plate; and a second plate made of an ionic material having a recessed portion to cover the at least one electrode at one face to face the piezoelectric plate. Each of the at least one electrode is packaged by direct bonding the piezoelectric plate with the first plate and the second plate so as to be sandwiched therebetween. A package includes a body member made of an ionic material provided with a recessed portion or an opening, having a flat face around the recessed portion or the opening; and a covering member made of an ionic material having a flat face to cover the body member.

Abstract: A method of rotating a non-temperature compensated Bechmann curve of a quartz strip. The method includes the steps of determining (102) whether a crystallographic orientation of an AT cut quartz strip is within a desired specification; selecting (104) a predetermined nominal electrode coverage having a nominal electrode width for an in-specification AT cut quartz strip; and tuning (106) an out of specification crystallographic orientation, by: adjusting (108) the electrode width with respect to the nominal electrode width, to bring the out-of-specification crystallographic orientation of an out-of-specification AT cut crystal quartz to within a desired specification having an in-specification Bechmann curve with an inflection point; and rotating (110) an out-of-specification Bechmann curve about the inflection point to substantially approach the desired in-specification Bechmann curve.

Abstract: An ultrasonic diagnostic transducer array is provided for providing electronic focusing in the longitudinal plane and elevational focusing. Elements of the array are subdiced in the elevational direction to provide subelements with aspect ratios varying in proportion to their distance to the central longitudinal axis of the array. Such variation affords varying electro-mechanical coupling coefficients to the subelements such that the intensity of the transmitted energy is centered about the central longitudinal axis. In a second embodiment elements exhibit extensions in the elevational direction which vary in proportion to their displacement from the longitudinal center of the array. The extended elements are acoustically separated into subelements in the elevational direction to provide elevational focusing or spatial compounding of the transmitted acoustic energy.

Abstract: An ultrasonic diagnostic transducer array is provided for providing electronic focusing in the longitudinal plane and elevational focusing. Elements of the array are subdiced in the elevational direction to provide subelements with aspect ratios varying in proportion to their distance to the central longitudinal axis of the array. Such variation affords varying electro-mechanical coupling coefficients to the subelements such that the intensity of the transmitted energy is centered about the central longitudinal axis. In a second embodiment elements exhibit extensions in the elevational direction which vary in proportion to their displacement from the longitudinal center of the array. The extended elements are acoustically separated into subelements in the elevational direction to provide elevational focusing or spatial compounding of the transmitted acoustic energy.

Abstract: First and second grooves (15, 16) are formed in upper and lower surfaces of a piezoelectric ceramic plate (12), which is polarized in a direction P parallel to its major surfaces, respectively. A resonance part is formed between the first and second grooves (15, 16), so that first and second resonance electrodes (13, 14) which are provided on the upper and lower surfaces of the piezoelectric ceramic plate (12) respectively are opposed to each other through the piezoelectric ceramic plate (12). In this energy trap type piezo-resonator utilizing a thickness shear mode, the resonance part has a pair of rectangular side surfaces, and the first and second grooves (15, 16) are so formed that a ratio b/a is in a range of .+-.10% from the following value:b/a=n(0.3.sigma.+1.48) (1)assuming that b and a represent lengths of longer and shorter sides of the rectangular side surfaces of the piezoelectric body respectively, .sigma.

Abstract: A surface-mountable crystal resonator (100) is provided in the following manner. A first predetermined electrode pattern (105) and a second predetermined electrode pattern (201) are formed on a first major surface (104) and a second major surface (200), respectively, of a piezoelectric crystal substrate (101). Additionally, a first predetermined attachment electrode pattern (106), electrically coupled to the second predetermined attachment electrode pattern, and a second predetermined attachment electrode pattern (202), electrically coupled to the first predetermined attachment electrode pattern, are formed on a first attachment area (102) and a second attachment area (103), respectively. The first and second attachment areas include extensions (107) that, when mounted, allow a conductive adhesive (301), placed on a mounting substrate (300), to flow and establish electrical connections with the first and second predetermined attachment electrode patterns.

Abstract: A sidewall actuated channel array for a high density ink jet printhead includes a top wall, bottom wall and a plurality of liquid confining channels formed between columns of polarized piezoelectric material. The array is formed from a plurality of sheets of polarized piezoelectric material which are joined together. Several embodiments are provided for distributing the joints between sheets of piezoelectric material to reduce the magnitude of the electric field needed to polarize the piezoelectric material.

Abstract: A high frequency oscillator with operating frequencies of 30 MHz or greater having an etched quartz thickness shear resonator with resonating means. The resonator has a support structure and a much thinner resonating membrane cantilevered from the support structure. In a preferred embodiment, the design of the support structure is such that a sloped edge is provided between the support structure and the membrane, thus facilitating the application of electrode resonating means extending from the support structure to the membrane. In another preferred embodiment, a plurality of resonators having a support structure and cantilevered membrane with at least one sloped edge are formed on a quartz wafer in a manner similar to semiconductor chip fabrication.

Abstract: An AT-cut crystal oscillating reed formed by etching an AT-cut crystal wafer is provided. The wafer has a rotational parallel cut obtained by rotating a parallel cut by an angular degree of .theta..degree. relative to the X-axis of the wafer. The etching cross-section of the AT-cut crystal oscillating reed has a surface at an angle about 90.degree. from the front or back surface of the AT-cut crystal oscillating reed. This AT-cut crystal oscillating reed exhibits uniform characteristics and excellent reliability. Also provided is an AT-cut crystal oscillating reed with a low CI value. Finally, a method of etching an AT-cut crystal oscillating reed from an AT-cut crystal wafer is provided. A corrosion resisting film with gaps coats the wafer and is used in the etching process. In a preferred embodiment, the thickness of the wafer is designated t, the width of the gaps in the corrosion resisting films is designated l, and l.gtoreq.t/tan .theta..

Abstract: A preferred embodiment of a resonator embodying the invention comprises entially a resonating plate, an action electrode and a detection electrode, and a supporting base. The electrodes are placed facing symmetrical narrow edges of the plate, opposite vibration loops, and are coupled to the plate by capacitive, electrostrictive or piezoelectric effect according to the material of which the plate is comprised. A very wide range of elastic solid materials can be used to embody the resonating plate. The plate is attached to the supporting base at points corresponding to vibration nodes of the plate. The plate vibrates advantageously according to a contour mode called Lame mode. High coefficients of quality in the region of 10.sup.7 are obtained. The resonators embodying the invention can be easily integrated. To do so, the plate is e.g. embodied in silicon. Such a resonator is included in a high-stability oscillating loop comprising a phase shifter and an amplifier.

Abstract: A width-extensional mode quartz crystal resonator formed by etching from a quartz crystal plate which is cut along a plane defined in the O-xyz coordinate system of the quartz crystal lattice by rotating the original Z plane around the x axis by a rotation angle in the range of 23.degree.-28.degree.. The quartz crystal resonator has a thickness-to-width ratio R.sub.zx in the range of 0.45-0.65. A pair of exciting electrodes are disposed on the resonator along opposed side faces perpendicular to the widthwise direction. The width-extensional mode quartz crystal resonator may be etched from a quartz crystal plate to provide a small sized resonator. A width-extensional mode vibrational portion is supported at its lengthwise sides by a pair of first bridge portions extending from a first frame portion. A pair of second bridge portions extend from a second frame portion and support the first frame at central portions of its lengthwise sides.

Abstract: An elongated mass is extended from the center of a U-shaped support frame and oscillators are disposed between the mass and leg portions of the support frame. The oscillators each have a flat, plate-like configuration which oscillates in a distorted-sliding oscillation mode.

Abstract: A laminated type piezoelectric actuator having a laminated body formed by alternately laminating piezoelectric ceramic layers and internal electrode layers, each of which are approximately the same shape. The four corners or edges of each layer of the ceramic layers and the internal electrode layers, which edges extend in parallel with the lamination direction of the laminated body, are machined to form a convex, arcuate shape or an angled, planar shape. This enables the end parts of each layer, which have a high distribution density of microcracks, to be removed, so that interlayer short-circuiting between the internal electrode films caused by the microcracks is prevented. Accordingly, the operation life and the reliability of the actuator of this invention is extended and improved, respectively, even when it is driven by a driving voltage which is exactly or close to that of a dc voltage in a highly humid environment. By using a Pb (Ni.sub.1/3 Nb.sub.2/3) O.sub.3 --PbTiO.sub.3 --PbZrO.sub.

Abstract: A longitudinal quartz crystal resonator has at least two vibrating arms arranged in parallel to each other to undergo a longitudinal vibration. The vibrating arms are connected together at both ends thereof by connecting sections. A pair of bridge sections extend from central parts of respective ones of the outermost vibrating arms and are connected to flexional sections. The bridge sections are supported through surrounding frame sections by a bottom mount section. The flexional sections are connected to the frame sections so as to form surrounding openings. By such construction, an equivalent inductance and a series resistance are reduced in the longitudinal quartz crystal resonator so as to eliminate vibrating energy loss.

Abstract: A vibrating crystal transducer for measuring temperature is disclosed. The crystal includes a single elongated vibrating beam that has a torsional mode resonant frequency that is a function of the temperature of the crystal. The torsional moments of the crystal are reverse symmetric with respect to a nodal line on the beam. The beam is contained in a frame that is secured to a sensor frame member. The beam is attached to the frame by a pair of opposed mounting posts that are in line with the nodal line on the beam. The beam, the beam frame (16) and the mounting posts are formed out of an integral section of crystalline material. When the beam is vibrated, the reverse symmetrically opposed torsional moments along the beam cancel each other out and, consequently, no torsional energy is transmitted through the mounting posts to the beam frame or the sensor frame.

Abstract: A resonator has a parallelepipedal bar of a piezoelectric material designed to vibrate in an extension mode, and suspension means of said bar which form a single, integral part with the latter and which are only connected to one of its lateral faces. This arrangement makes it possible to reduce the number of parasitic vibration modes which could couple to the main mode as well as coupling between these modes, and hence variations as a function of the temperature in the characteristics of the resonator, notably in its quality factor.

Abstract: A method of producing a multilayer piezoelectric element. The multilayer is formed of layers of piezoelectric synthetic resin material, such as PVDF and metal layers, such as Al. The multilayer is made form-retaining and mechanically stable by use of heat and pressure. Connections are provided on two facing sides of the multilayer which preferably include at least one sprayed metal layer, which preferably consists of the same metal as the metal layers of the multilayer.

Abstract: A length-extentional quartz resonator has a pair of linearly arranged longitudinal oscillating portions supported to undergo dominant length-extentional oscillation having an oscillating frequency in the range from 1.04 MHz to 1.06 MHz. A rectangular frame member is arranged to support and surround the oscillating portions and has the outer overall length of 4000 .mu.m.+-.200 .mu.m. The frame member has a pair of longitudinal frame portions connected to the oscillating portions through transverse support portions to undergo flexual oscillation, and having width set in the range from 110 .mu.m to 260 .mu.m effective to suppress coupling between the dominant length-extentional oscillation and the flexual oscillation.

Abstract: A method and arrangement for providing damping of undesired modes of piezoelectric vibrators is disclosed that eliminates the tedious and often inaccurate methods of known mass-loading techniques. Instead, the arrangement relies on physically altering a controlled amount of the piezoelectric material located at a predetermined point to effect the selective damping needed to minimize the undesired responses and to minimally interfere with the desired mode of operation.

Abstract: When making curved bar probes it is necessary, particularly at high frequency, to provide circuits for the connection of piezoelectric elements of the bars which are compatible with the curvature imposed to the bar after it has been fabricated flat. The invention overcomes such difficulty by adjoining on both sides of the elements a generally parallelepipedic relay metallized on at least two (12,13) of its adjacent faces to transpose one connection face (7) situated in plane which must be curved into one connection face (13) which is perpendicular and of which the orientation remains unchanged and parallel to a same plane during the curvature operation. As a result, the connection is simplified.

Abstract: A small longitudinal quartz crystal resonator has an intermediate oscillating frequency from 500 KHz to 4.2 MHz, a reduced energy loss of vibration, a small equivalent series resistance and zero temperature coefficient. The resonator has a longitudinal vibrational portion of rod-like shape connected at its central portion to a pair of supporting portions through each bridge portion. Each supporting portion is shaped to avoid suppression of oscillation of the vibrational portion. The vibrational and supporting portions are formed integrally by etching method. Driving electrodes are formed on etched faces of the vibrational portion perpendicular to X-axis. The resonator is composed of a quartz crystal plate cut out by cut angle of -2.degree. to +4.degree. around X-axis with respect to a Z-plate. The vibrational portion may have tapered end portions to increase the oscillating frequency in high frequency range up to 4.2 MHz.

Abstract: A temperature measurement device is provided with a temperature sensing element which contains a quartz resonator having a quartz oscillating crystal whose ratio of width to thickness is in the range of 9.48 to 9.69, and an antenna which receives stimulus for the quartz oscillating crystal and transmits waves of reverberatory oscillation. The temperature measurement device is capable of measuring temperatures in the range of normal room temperature to extremely low temperatures (4.degree. K.).

Abstract: A technique is described for tailoring the configuration of electrodes on a piezoelectric beam such that the tendency of the beam to vibrate in a predetermined flexure mode is enhanced. The mode has a predetermined longitudinal strain versus longitudinal position profile. At least two electrodes are mounted on the beam, and the configuration of at least one electrode varies as a function of longitudinal position, such that when a voltage difference is applied between the electrodes, the longitudinal force produced by the electrodes, as a function of longitudinal position, approximates the longitudinal strain versus longitudinal position profile. The configuration may be varied by varying the width of the electrode or the position of the electrode on the underlying beam surface.

Abstract: A piezoelectric resonator formed as a thin parallelepipedic quartz plate whose width is arranged along the electric axis X of the crystal, the length along an axis Y' and the thickness along an axis Z', wherein the axes Y' and Z' form an angle approximately equal to 24.degree. with the mechanical axis Y and the optical axis Z of the crystal, respectively, and the ratio w/l of its width to its length is approximately equal to 0.64.

Abstract: An assembly of a plurality of resonators is formed in which the resonators are held edge to edge and fixed relative to each other. The assembly is held together by two rigid strips mounted on opposing surfaces near the central regions of the resonators. The assembly is disposed in a longitudinal pipe which contains an abrasive material. The pipe is rotated about its axis causing the assembly to nonrandomly tumble in the abrasive so that the projecting ends of the resonators have material removed. Thus, resonators having rounded or contoured ends are produced.

Abstract: A face shear mode quartz crystal resonator having a vibrational portion and supporting portions incorporated therein by an etching method. A flexural portion of the supporting portion is connected with a central portion of a side of the vibrational portion. The width W and length L of the flexural portion connected with the vibrational portion are designed so as to meet "W.ltoreq.0.67L". The supporting portions are provided at the edges in the z'-axis direction of the vibrational portion which is substantially square and fixedly supported via both distal end portions of the supporting portions, and each side of the vibrational portion is from 0.72 mm to 2.02 mm.

Abstract: Ultrasonic transducer having a plurality of piezoelectric elements arranged in a matrix, and a method for fabricating them. L shaped printed wiring boards are respectively bonded to each arrays of piezoelectric elements arranged in azimuthal direction. The bonding points of the L shaped printed wiring board to respective piezoelectric element are located at edge portion of respective back electrode. The other branch of L shaped printed wiring boards are stretched vertically to the surface of the piezoelectric elements matrix. A backing plate is formed by molding on the back side of the piezoelectric elements matrix leaving the top of the L shaped printed wiring board protruded from the molded surface of the molded backing plate. Such configuration prevents the reflection from the wiring plate of the piezoelectric element. A flexible printed wiring board is provided with wiring pattern having bonding areas positioned corresponding to the matrix of piezoelectric elements.

Abstract: A piezoelectric resonator includes a base plate and a strip-type, energy trapping piezoelectric resonator chip mounted on the base plate. The piezoelectric resonator chip includes a piezoelectric chip plate and a pair of electrode patterns formed on the opposed main surfaces of the piezoelectric chip plate. One main surface of the piezoelectric chip plate faces the base plate and is parallel therewith, and a conductive layer is formed on each end of the main surface facing the base plate. The thickness of the conductive layer is greater than that of the electrode pattern so that the electrode pattern is separated from the base plate. The conductive layer is directly mounted onto a conductive portion of the base plate, so as to electrically connect the electrode pattern and the conductive portion of the base plate.

Abstract: A multi-layer transducer array for an ink jet apparatus having a plurality of variable-volume chambers includes a plurality of thin plates of piezoceramic material stacked one upon the other. Each of the plates are adapted to be coupled to a respective one of the chambers, and are formed with an active piezoelectric region which is separated from a structured region by a cut through the material leaving only one end of the active region connected to the structural region. One side of the active region is coated with a conductive material, thereby providing electrical connection to a thin foil strip arranged at the end of the plate remote from the chambers. Successive layers of such plates are stacked one on top of the other, with adjacent active regions staggered relative to each other, and with the thin foil strip between adjacent pairs of plates providing both mechanical isolation and a connection for electrical signals to pulse selected transducers.

Abstract: A piezoelectric vibrator of thickness-shear mode including a vibrating plate made of AT-cut quartz and a pair of electrodes applied on major surfaces of the vibrating plate in opposition to each other. A part of a contour of the vibrating plate is made closer to the electrode by cutting off a corner of a square vibrating plate. An impedance of the piezoelectric vibrator for a fundamental vibration is extremely increased to suppress the fundamental vibration and thus the piezoelectric vibrator can vibrate stably at a third overtone frequency.

Abstract: An apparatus for the examination of objects with ultrasound, comprising a linear or two-dimensional array (10) of piezo-electric transducer elements (10 (1), . . . , 10 (n)) with a length L and a width W, a stage for the repeated transmission of ultrasonic signals and a stage for the reception and processing of the ultrasonic echoes received. The thickness T of the elements is equal to half the wavelength corresponding to a first frequency F for which there exists, on the two-dimensional diagram of the curves F.multidot.T=f(W/T), or respectively, on the three-dimensional diagram of the curves F.multidot.T=f(W/T, L/T) of the distribution of the resonance frequencies, a first vibratory mode at the said first frequency F and a second vibratory mode at a second frequency equal to or near 2F. The transmission stage incorporates a generator (20) of excitation signals at the first frequency F, the spectrum of these excitation signals excluding at least the second frequency.

Abstract: An ultrasonic detection sensor having an integrated structure and formed of a substrate such as used for thick film circuits on which is secured at least one ultrasonic transducer formed of a film packet having n piezo ceramic films and n+1 plastic films. One outermost plastic film layer is secured to the substrate, serving as a backing for the transducer, and a thick film electrical circuit is formed on the same substrate.

Abstract: An improved method and apparatus is disclosed for perpendicularly mounting an AT-strip resonator on its longitudinal edge. The crystal blank is secured to the base at two or more mounting points via conductive cement which provides both electrical connection and mechanical support. A mounting cavity or slot permits proper positioning and self-fixturing during manufacture. The edge-mounting configuration promotes ease of manufacture, improved shock performance, minimized motional resistance degradation, and high packing density.

Abstract: The ink ejecting portion of an ink jet printer is described, wherein a single ceramic transducer is used to create the pressure for the ink droplets. Unlike prior devices, the transducer is a one-piece member as opposed to use of a piezoceramic material and diaphragm. The one-piece member is a piezoceramic material having a notch configuration at the location of each chamber.

Abstract: A piezoelectric resonator including a piezoelectric substrate of a quadrilateral or rectangular configuration, and electrode layers provided over opposite main faces of the piezoelectric substrate for vibration of the piezoelectric substrate on the whole, and characterized in that the piezoelectric substrate is formed, in its four side edges, with notched portions having dimensions and shapes different from each other.

Abstract: A resonator (1) is described for vibrating in a thickness-shear mode and has auxiliary electrodes (7f, 8d) between the zone of its main excitation electrodes (3, 4) and the zone of its connection terminals (5, 6) to generate an auxiliary vibration in opposition of phase with respect to the main vibration.The presence of the auxiliary electrodes (7f, 8d) improves notably the quality factor of the resonator.

Abstract: A piezoelectric vibrator adapted to operate in a spreading vibrating mode comprises compensation parts for compensating for the non-vibratory, or dead, region of a piezoelectric element which is formed between two confronting coupling pieces. The compensation parts comprise peripheral parts of the piezoelectric element that extend in an non-uniform manner from a center line passing through the respective centers of the confronting coupling pieces.

Abstract: In a piezoelectric vibrator capable of vibrating under an expansion mode of vibration, which has a piezoelectric vibrating element including a generally rectangular vibrateable substrate, made of a metallic material having a constant modulus of elasticity. The substrate is supported by a retaining member through a pair of connecting elements which extend outwardly from an arbitrarily chosen pair of side edges, respectively, so as to terminate in rigid connection with the retaining member. The width of each of the connecting elements as measured in a direction lengthwise of each of said edges is selected to be within the range of 1/7 to 1/3 of the length of said each side edge.

Abstract: The micro-resonator comprises, cut from the same quartz crystal, a bar and a suspension frame means. The bar is cut in a substantially Z cut mode. The excitation electrodes are disposed on the sides of the bar. The length of the bar is substantially parallel to the Y axis.This produces a resonator which vibrates in a main mode of extension-compression, at from 0.5 MHz to 4 MHz.

Abstract: An ultrasonic transducer comprising a network of parallel piezoelectric transducer elements having a width W or in the form of a parallelepipedon having a length H and a width W, characterized in that the thickness T of the said transducer elements is equal to half the wavelength corresponding to a frequency F which is equal to the average value of at least two of the successive piezoelectric resonance frequencies of the piezoelectric material concerned, the products of the thickness and the resonance frequencies framing at least two successive vibratory modes of this material in the bidimensional diagram of the curves F.multidot.T=f(W/T) of the spread of the resonance frequencies relating to the piezoelectric material concerned or in the tridimensional diagram of the curves F.multidot.T=f(W/T, H/T).