Abstract: An efficient ripple free wide-band single-phase unidirectional SAW transducer is disclosed which requires only a single tuning circuit and a single matching circuit. The unidirectional transducer includes a pair of bidirectional transducers the first of which is connected to a single-phase drive source and the second is connected to a resonant load such that the second transducer acts as a reflecting transducer to cancel out waves traveling in one direction.

Abstract: A protection plate 36a and a protection plate 36b, which are each of a substantially rectangular shape and which extend upwards from respective substantially central portions of opposite lengthwise ends of an attachment platform 34, are formed in the attachment platform 34 by bending part of the attachment platform 34. Also, stoppers 46a and 46b, which have notches 48for protecting two surfaces on either side of the ridge line of the oscillator 12, are attached to the attachment platform 34. Further the oscillator 12, the attachment platform 34, and the stoppers 46a and 46b etc. are housed in a box-shaped case 50. Accordingly, the vicinities of both lengthwise ends of the oscillator 12 are surrounded and protected by the stoppers 46a and 46b. The protection plates 36a and 36b, and the inner side surface of the case 50 as the protection members in the predetermined space d. By means of this structure, an oscillation gyroscope is provided in which the shock resistance is further improved.

Abstract: A transducer apparatus is disclosed including a spool member having a body portion and first and second elevated regions formed on the body portion. A piezoelectric film such as a PVDF film surrounds the spool member and is spaced apart from the body portion of the spool member by an elevation of the elevated region, thereby forming a predetermined gap between the piezoelectric film and the body portion of the spool member. The predetermined gap is at least 0.1 mm and enables a predetermined resonance frequency in the piezoelectric film to control the resonance frequency of the transducer. Opposite lateral ends of the piezoelectric film are secured together such that secured ends of the piezoelectric film have substantially the same resonance frequency as a remainder of the piezoelectric film.

Abstract: A piezoelectric/electrostrictive device is provided in which a connection plate whose one end in the longitudinal direction is held by two diaphragms and whose other end is held by two other diaphragms is spanned between bottoms of faced concave portions formed on a substrate, and piezoelectric elements are arranged on at least a part of at least one-side plane surface of each of the diaphragms, and the diaphragms are connected with the sides of the concave portions in at least the direction for the diaphragms to hold the connection plate, and a fixing plate is connected to the connection plate so that the longitudinal direction of the fixing plate becomes parallel with the direction for the diaphragms to hold the connection plate. A displacement of the fixing plate generated by applying a voltage to the piezoelectric element is utilized or an electromotive force of the piezoelectric element based on a displacement of the fixing plate is utilized.

Abstract: A piezoelectric vibration device utilizes a thickness-shear vibration available for communication devices or the like. The piezoelectric vibration device has a structure wherein at least one of each peripheral zone of an input electrode (21) and an output electrode (22), or a common electrode (23), where the non-harmonic overtone mode is relatively strongly excited, is partially provided with either a weight reducing portion (231, 232) or a weight adding portion. Moreover, an area of the common electrode (23) is larger than a total area of the input electrode (21) and the output electrode (22), and either the weight reducing portion (231, 232) or the weight adding portion reaches the common electrode (23) opposed to the input electrode (21) and the output electrode (22). Preferably, the common electrode formed on one principal plane of a quartz plate (1) is twice to 10 times as thick as the input electrode (21) and the output electrode (22) formed on the other principal plane.

Abstract: An energy-trap piezoelectric resonator utilizing thickness extensional vibration includes a piezoelectric substrate and first and second resonance electrodes. The piezoelectric substrate is polarized in the thickness direction thereof and has first and second main surfaces. The first resonance electrode is partially disposed on the first main surface of the piezoelectric substrate, and the second resonance electrode is partially disposed on the second main surface of the piezoelectric substrate. The second resonance electrode is arranged to oppose the first resonance electrode with the piezoelectric substrate disposed therebetween and has an external dimension that is different from that of the first resonance electrode.

Abstract: An energy-trap thickness extensional vibration mode piezoelectric resonator uses a harmonic of a thickness extensional vibration mode and effectively suppresses generation of unwanted spurious vibrations. The energy-trap thickness extensional vibration mode piezoelectric resonator includes a piezoelectric strip, first and second excitation electrodes located on opposite surfaces of the piezoelectric strip, and an internal electrode disposed inside the piezoelectric strip. The first and second excitation electrodes are located on opposite ends of the piezoelectric strip in an overlapping arrangement. The internal electrode is located opposite to the first and second excitation electrodes. The first and second excitation electrodes overlap each other over a length of l such that l/d is not greater than about 6, where d=t/n.

Abstract: An electroactive device incorporating the invention includes an electroactive ceramic annular substrate having a pair of opposed planar annular surfaces, a hollowed interior region and a thickness aspect. A first cap having a concave shape that extends into the hollowed interior region includes a rim portion, bounding the hollowed interior region, and joined to a first one of the planar surfaces. A second cap having a concave shape that extends into the hollowed interior region includes a rim portion, bounding the hollowed interior region, and joined to a second one of the planar surfaces. A potential measured across the ceramic substrate enables a field change in the ceramic substrate to be sensed, the field change caused by flexure of the ceramic substrate as a result of a pressure applied to the first and second caps.

Abstract: An apparatus comprises first and second piezoelectric elements 25a, 25b each extending and contracting in a driving direction, a fixed member 32 secured to one end of each of the first and second piezoelectric elements 25a, 25b, first and second guide shafts 28a, 28b secured to the other ends of the respective first and second piezoelectric elements 25a, 25b to reciprocate with the extension and contraction of the aforesaid piezoelectric elements, first and second lens frames 21a, 21b held frictionally by the first and second guide shafts 28a, 28b, and a drive pulse generator for causing the slow and rapid displacements of each of the first and second piezoelectric elements 25a, 25b and outputting drive pulses such that a period during which the first piezoelectric element 25a undergoes rapid displacement does not coincide with a period during which the second piezoelectric element 25a undergoes rapid displacement.

Abstract: A thickness-extensional piezoelectric resonator using a harmonic of a thickness-extensional vibration mode has a compact size, large electric capacity, and small variations in resonance characteristics, and is not affected by the stray capacitance of a circuit board. The thickness-extensional piezoelectric resonator includes a substantially rectangular-plate piezoelectric body, a first excitation electrode and a second excitation electrode disposed on individual surfaces of the piezoelectric body, and an internal electrode inside of the piezoelectric body. Portions where the first excitation electrode, the second excitation electrode and the internal electrode overlap define a resonating portion. In the length direction of the piezoelectric body, a vibration-attenuating portion is defined at each side of the resonating portion, whereas in the width direction, the vibration-attenuating portion is not provided at each side thereof.

Abstract: A multi-layered piezoelectric electrical energy transfer device has its input and output sides electrically isolated from each other. As a transformer, the device provides step-down voltage conversion while the output signal preserves the input signal frequency in a broad bandwidth. For telecommunications applications, the transformer can provide impedance matching with transmission lines, which minimizes line losses and echoes that seriously degrade high-speed data transmission. The piezoelectric transformer also provides a uniform voltage transformation ratio (Vout/Vin) over wide frequency ranges, and is adaptable for simultaneous audio and data signal telecommunications applications requiring wide bandwidth service.

Abstract: A monolithic piezoelectric transformer includes a piezoelectric substrate and input electrodes which include internal electrodes disposed in the piezoelectric substrate alternately and between piezoelectric ceramic layers and external electrodes provided on the corresponding upper and lower surfaces of the piezoelectric substrate. The length of the external electrodes is about 50% of an overall length L of the piezoelectric substrate. The length of the internal electrodes is longer than approximately 50% of the overall length L.

Abstract: An ultrasonic probe including a plurality of transducer elements for transmitting an ultrasonic wave and receiving a reflected ultrasonic wave from inside of an object to be examined, electrodes for applying a voltage to the transducer elements, and an acoustic matching layer for taking a matching of an acoustic impedance between the transducer elements and the object to be examined, wherein the acoustic matching layer includes a plurality of materials each of which has a different acoustic impedance and has an anisotropy in acoustic characteristic between an ultrasonic wave-transmitting direction from the transducer elements and a direction perpendicular to the ultrasonic wave-transmitting direction.

Abstract: Transducer elements having a 2-2 or 1-3 composite structure and driven in a k31 transverse mode for small-feature size transducer arrays, which provide improved electrical impedance matching to an ultrasonic imaging system and improved acoustic matching to the human body. The transducer element includes a plurality of thin piezoceramic wafers which are electroded on opposing major surfaces. The spaced wafers are separated by a passive polymer layer in a composite structure. Methods of producing the transducer elements are also described.

Abstract: A piezoelectric or electrostrictive actuator, comprising a plurality of stages of piezoelectric or electrostrictive active blocks distributed so as to form a tubular structure, the polarization of the active blocks alternating from one stage to the next, separation elements separating the unit active blocks of any one stage in pairs, said elements being superposed on one another in the height direction of the structure, being suitable for sliding over one another, and being of stiffness greater than that of the unit active blocks, a separation element extending over the height of two stages of active blocks, the separation elements on either side of a given unit active block extending respectively through both stages on either side of said unit active block, electrode-forming means enabling voltages of alternating sign to be applied to the various stacks of active blocks, and wherein a separation element is constituted by two bonded-together slabs each belonging to a different stage, the slabs of any one stag

Abstract: A spectrum diffusion signal including data representing a center frequency of an acoustic surface filter in a transmitter side is transmitted with its carrier-frequency being swept. When a receiver side receives a modulation signal, a spectrum diffusion signal including data representing a center frequency of an acoustic surface filter in a receiver side is transmitted on the carrier-frequency equal to the center frequency of the surface acoustic wave matched filter in the transmitter side included in the modulation signal. Thereafter, the transmitter side transmits spectrum diffusion signals having the carrier-frequency equal to the center frequency of the surface acoustic wave matched filter in the receiver side included in the modulation signal.

Abstract: A megasonic cleaning system comprised of a container, a resonator, a piezoelectric crystal and an indium layer for attaching the resonator to the piezoelectric crystal. The container includes a fluid chamber for holding a volume of cleaning solution. The resonator is selected from the group consisting of sapphire, quartz, silicon carbide, silicon nitride and ceramic. The resonator forms the bottom of the container and has an interface surface which abuts the fluid chamber.

Abstract: The drive section made by bonding the piezoelectric material on part of the elastic shim and the displacement amplifying section which amplifies the amplitude of vibration vibrated in the drive section are provided in the same plane. The device is driven at drive frequencies in a region between the resonance frequency of the drive section and the resonance frequency of the displacement amplifying section.

Abstract: An assembly for utilization in a loudspeaker system is disclosed. The assembly comprises a substantially flat piezoelectric element capable of being excited by applied electric potential, a diaphragm that is driven by the excited piezoelectric element, said diaphragm having a surface area that is at least 20 times the surface area of the piezoelectric element and at least one motion coupler which is attached to at least a portion of the outer perimeter of the piezoelectric element and on its underside to the diaphragm.

Abstract: A vibration device has a vibration member for exciting vibration by supplying power to the vibration device. A signal supply member for sandwiching the vibration member such that the vibration member can be elastically deformed supplies a driving electric signal to the vibration member.