Abstract: In a piezoelectric device, a first electrode, a first piezoelectric film, a second piezoelectric film, and a second electrode are formed in this order on a first electrode formed above a surface of the substrate, and an intermediate electrode is arranged between the first and second piezoelectric films. Each of the first and second piezoelectric films has a thickness of 10 micrometers or smaller, and has a first surface facing toward the substrate and a second surface opposite to the first surface. At least one of the first and second surfaces has an arithmetic average surface roughness (Ra) of 0.5 micrometers or smaller.

Abstract: [Object] To provide a piezoelectric device having excellent drive level characteristics in terms of downsizing, having no remaining stress at the bonding portion of the container and leaving no characteristics deteriorating factors. [Solving Means] A piezoelectric device includes: a base substrate 54, a framed resonator element 55 stacked and fixed on the base substrate, a lid 56 stacked and fixed on the framed resonator element, wherein the base substrate, the framed resonator element, and the lid are made from the same materials or the materials having highly approximate linear coefficients of expansion and the bonding surfaces thereof are bonded with each other by surface activating process so as to be vacuum-sealed.

Abstract: A method of poling a piezoelectric actuator, which can improve the uniformity of a plurality of piezoelectric actuators. In the method, a plurality of piezoelectric actuators are prepared for poling. Then, at least two preliminary poling processes are performed on the prepared piezoelectric actuators under different preliminary voltages and displacements of the piezoelectric actuators subjected to each of the at least two poling processes are measured. A relationship between a voltage and a displacement for each of the piezoelectric actuators is established. Poling voltages are calculated so that the piezoelectric actuators can have the same target displacement. Formal poling is performed on the piezoelectric actuators under the calculated poling voltages. The displacements of the piezoelectric actuators, which have completed the formal poling, are measured.

Abstract: A liquid discharging head includes: a plurality of nozzles that discharge liquid droplets; and a plurality of piezoelectric elements that generate pressure for discharging liquid droplets from the respective nozzles, wherein the piezoelectric elements are performed with repolarization process to set non-uniformity of the droplet discharging characteristics of the nozzles to be in a predetermined range by combining adjustment of a polarization sensitivity and adjustment of a polarization voltage for each of the piezoelectric elements.

Abstract: A piezoelectric laminate including a base and a first piezoelectric layer formed above the base and including potassium sodium niobate. The first piezoelectric layer is shown by a compositional formula (KaNa1-a)xNbO3, “a” and “x” in the compositional formula being respectively 0.1<a<1 and 1?x?1.2.

Abstract: Disclosed are a method for driving a piezoelectric element or an optical modulator including a piezoelectric element and a recorded medium recorded with a program for executing the same. In accordance with an embodiment of the present invention, the method for driving a piezoelectric element causing a displacement object to be displaced by being contracted or expanded according to a supplied driving voltage, including supplying a driving signal to the piezoelectric element during a first driving period in a first voltage range; supplying a control signal for controlling a polarization hysteresis of the piezoelectric element according to a driving, performed during the first driving period, to the piezoelectric element; and supplying the driving signal to the piezoelectric element during a second driving period in a second voltage range.

Abstract: A piezoelectric plate electric connection structure aims to receive an input voltage from a voltage source and goes through a polarization process to deliver an output voltage. It has an input electrode on a piezoelectric plate to receive input from the voltage source and an output electrode to deliver the output voltage that are located on two surfaces normal to the polarization direction. One surface has an independent electrode. Another surface has two separated electrodes. The input electrode and output electrode are respectively the independent electrode and one of the separated electrodes. The input and output electrodes are spaced by the piezoelectric plate which is dielectric and pressure-resistant. Thus discharge phenomenon can be prevented between the input electrode and the output electrode.

Abstract: The subject invention provides composite articles (20, 120) and associated systems (32, 132). A first composite article (20) includes a piezoelectric layer (22) having a piezoelectric property. The piezoelectric layer (22) is sandwiched between a first conductive layer (28) and a second conductive layer (30). At least one of the conductive layers (28, 30) is a conductive polymer having an electrically conductive property. A second composite article (120) includes first and second piezoelectric layers (122, 124) having a piezoelectric property. The first and second piezoelectric layers sandwich an insulating layer (126). A first system (32) and a second system (132) each include a control device (34) electrically connected to the first composite article (20) or the second composite article (120), respectively.

Abstract: Disclosed is an ultrasonic motor whose output is improved by enhancing the exciting force of a vibration caused on a vibrating body having a rectangular portion. The ultrasonic motor includes the vibrating body having a piezoelectric element, and a moving body which contacts the vibrating body. The phases of two difference vibrations caused on the vibrating body are changed to make the moving direction of the moving body or the vibrating body itself variable by selecting whether to apply a drive signal to first electrodes provided at one side of the piezoelectric element or to apply a drive signal to second electrodes provided at a portion whose polarization direction differs from that of the first electrodes.

Abstract: A piezoelectric actuator includes a vibration plate which is joined to a flow passage unit to cover a pressure chamber formed in the flow passage unit, a piezoelectric layer arranged on the vibration plate, a first electrode arranged on the piezoelectric layer to face the pressure chamber, a second electrode arranged on the piezoelectric layer while being opposed to the first electrode, and a third area arranged in the remaining area of the piezoelectric layer opposed to the pressure chamber. A first portion of the piezoelectric layer interposed by the first and second electrodes is polarized in parallel to the thickness direction. A second portion of the piezoelectric layer disposed between the first and third electrodes in the plane direction, is polarized in parallel to the plane direction. Accordingly, there are provided the piezoelectric actuator having a high driving efficiency.

Abstract: A piezoelectric element includes: a base substrate; a lower electrode formed above the base substrate; a ferroelectric layer formed above the lower electrode; and an upper electrode formed above the ferroelectric layer, wherein an angle of a corner defined by a side surface of the ferroelectric layer and a top surface of the base substrate is between 45° and 75°.

Abstract: A piezoelectric device includes a substrate; and a laminated film formed above the substrate. The laminated film includes a lower electrode layer, a piezoelectric layer, and an upper electrode layer formed in this order, and the lower electrode layer is a metal electrode layer containing as one or more main components one or more nonnoble metals and/or one or more nonnoble alloys. Preferably, the one or more main components are one or more of the metals Cr, W, Ti, Al, Fe, Mo, In, Sn, Ni, Cu, Co, and Ta, and alloys of the metals.

Abstract: A magneto-electric (ME) gyrator, which is a discrete, passive network element, comprises a laminated composite of piezoelectric and magnetostrictive layers. The ME gyrator approximately meets the following criteria: Vy=??/,, where V is voltage, /is current, and a is a conversion (or gyration) coefficient between voltage and current and non-reciprocity is manifested as a 180° phase shift between open and short circuit (/,F) conditions, and =* 1 (Ib) where c0 is the speed of light in vacuum, ?e?is the effective relative dielectric constant, and ?c?is the effect?ive relative permeability.

Abstract: A piezoelectric pump includes a piezoelectric vibrator whose periphery is fluid-tightly sealed, and a pump chamber and an air chamber that are formed on front and rear sides of the piezoelectric vibrator. The piezoelectric pump vibrates the piezoelectric vibrator to perform a pumping operation. The piezoelectric vibrator includes: a shim that is formed of a conductive thin metal plate and has one surface abutting on the pump chamber; and a laminate of a plurality of piezoelectric element layers that is formed on the other surface of the shim so as to face the air chamber or the pumping chamber. The plurality of piezoelectric element layers are polarized and connected to wiring lines such that the amplitude of the vibration of the piezoelectric vibrator is larger than that of a piezoelectric vibrator including a single-layer piezoelectric element.

Abstract: A piezoelectric transducer defined by two faces comprises a plurality of piezoelectric cylinders. The axial length and composition of the piezoelectric cylinders determines the frequency of the transducer when excited. The axial ends of the piezoelectric cylinders are aligned with the faces. The piezoelectric cylinders are separated from each other and the space therebetween is fully or partially empty such that crosstalk between piezoelectric cylinders is substantially eliminated. Electrodes are produced at the faces of the transducer for simultaneously exciting the piezoelectric cylinders.

Abstract: A method of producing an actuator includes shaping a block of ferroelectric material to provide an active element of the actuator. The element includes a stack of ferroelectric layers with adjacent layers separated by electrodes arranged parallel to end faces of the element. The method includes applying a primary electrode to the end faces, immersing the element and the primary electrode within a dielectric fluid, applying a primary poling voltage to the primary electrode so as to polarize the element in a first polarization direction, applying a secondary external electrode to side faces of the element, and applying a secondary poling voltage to the secondary electrode to polarize alternate layers along the first polarization direction and the other layers along a second, oppositely-directed polarization axis. The method may also include applying a conductive film to the end faces and/or applying heat to help evaporate the dielectric fluid.

Abstract: A vibration control apparatus capable of efficiently generating vibrations of different orders using the same electrodes. A plurality of electrodes polarized to have desired polarities are formed in a piezoelectric element, and are divided into a plurality of electrode groups each comprised of electrodes including two or more electrodes with different polarities. Phases and frequency of alternating voltages applied to the electrode groups are changed, thereby generating vibrations of different orders.

Abstract: There is disclosed a piezoelectric/electrostrictive device which exhibits an excellent piezoelectric characteristic and which has an only small dependence on a temperature so that the piezoelectric characteristic does not easily change with the temperature. A piezoelectric/electrostrictive device includes a piezoelectric/electrostrictive portion made of a piezoelectric ceramic, and electrodes electrically connected to the piezoelectric/electrostrictive portion. The piezoelectric ceramic can reversibly transit to a tetragonal phase and an orthorhombic phase at a phase transition point as a boundary, and the piezoelectric/electrostrictive portion is formed by a polarization treatment performed on conditions that a treatment temperature ranges from a temperature which exceeds the phase transition point of the piezoelectric ceramic to a temperature which is 50° C. higher than the temperature.

Abstract: A ferroelectric thin film element comprises a substrate and an epitaxial ferroelectric thin film provided on the substrate. The thin film satisfies z/z0>1.003 and 0.997?x/x0?1.003, where a crystal face of said thin film parallel to a crystal face of a surface of the substrate is taken as a Z crystal face, a face spacing of the Z crystal face is taken as z, a face spacing of the Z crystal face of a material constituting the thin film in a bulk state is taken as z0, a crystal face of the thin film perpendicular to the Z crystal face is taken as an X crystal face, a face spacing of the X crystal face is taken as x and a face spacing of the X crystal face of the material constituting the thin film in a bulk state is taken as x0.

Abstract: A piezoelectric transformer includes a piezoelectric ceramic disc having one face and the other face opposite to each other in a thickness direction. A pair of low-impedance portions acting as one of a driving portion and a generator portion are disposed in the piezoelectric ceramic disc symmetrically with respect to a central axis of the piezoelectric ceramic disc, while a pair of high-impedance portions acting as the other of the driving portion and the generator portion are disposed in the piezoelectric ceramic disc symmetrically with respect to the central axis so as to be electrically separated from the low-impedance portions such that the piezoelectric transformer is driven in a radial extensional vibration mode of the piezoelectric ceramic disc.

Abstract: A method for fabricating a piezoelectric macro-fiber composite actuator comprises making a piezoelectric fiber sheet by providing a plurality of wafers of piezoelectric material, bonding the wafers together with an adhesive material to form a stack of alternating layers of piezoelectric material and adhesive material, and cutting through the stack in a direction substantially parallel to the thickness of the stack and across the alternating layers of piezoelectric material and adhesive material to provide at least one piezoelectric fiber sheet having two sides comprising a plurality of piezoelectric fibers in juxtaposition to the adhesive material. The method further comprises bonding two electrically conductive films to the two sides of the piezoelectric fiber sheet. At least one conductive film has first and second conductive patterns formed thereon which are electrically isolated from one another and in electrical contact with the piezoelectric fiber sheet.

Abstract: The invention provides a defect inspecting apparatus and a defect detecting method for specifying a position of a defect before polarization when the defect is included in a coaxial flexible piezoelectric member. Further, when a piezoelectric tube is moved in polarization, a friction force is produced between the coaxial flexible piezoelectric member and a block-like conductor and therefore, a large force is needed in moving the piezoelectric tube. The invention provides a polarizing apparatus and a polarizing method capable of moving the piezoelectric tube even by a small force. There are provided a defect detecting apparatus of a coaxial flexible piezoelectric member having a constitution of applying a direct current to a coaxial flexible piezoelectric member while moving a piezoelectric tube arranged at a hole of inspecting electrode means and a marking apparatus for marking a defect portion.

Abstract: A method for making a piezoelectric actuator comprises coating at least one of a first surface and a second surface of a piezoelectric element with a polyimide adhesive. The piezoelectric element is then heated to dry the adhesive. Afterwards, the piezoelectric element is inserted between a first metallic layer and a second metallic layer to form an assembly. The assembly is placed in a press. While the assembly is in the press, the polyimide adhesive is cured at a curing temperature which does not depole the piezoelectric element, thereby bonding the piezoelectric element between the first metallic layer and the second metallic layer.

Abstract: In a vibrator support structure, a vibrator is supported on a substrate through support pins, substrate connection portions of the support pins and pin connection portions of the substrate are joined through conductive adhesive which is made of a resin including conductive filler and has a pencil hardness of about 4H or less, and the conductive adhesive has a thickness which can buffer vibrations and impacts propagated through the support pins.

Abstract: A method of manufacturing a piezoelectric actuator, formed of multiple concave parts which are provided on one surface. First, a first sheet is formed of pliant piezoelectric materials and a second sheet is formed of pliant predetermined materials, forming an upper electrode layer formed of conduction materials on one surface of said first sheet, and forming a lower electrode layer formed of conduction materials on the other surface of said first sheet or one surface of said second sheet, wherein piezoelectric material is used as said material of the second sheet and electrode layer for polarization formed of conduction material is formed on the other surface side of said second sheet. Next, the first and second sheets are piled and densified. The first sheet is polarized in a direction of a thickness of the first sheet.

Abstract: A multi-electrode piezoelectric diaphragm structure includes a diaphragm, piezoelectric material located on the diaphragm, which is defined as having a first area, and a second area. The first area of the piezoelectric is poled in a first direction, and the second area of the piezoelectric is poled in a second direction. The poled first direction is in a Z-axis of the piezoelectric and the poled second direction is in a Radial axis of the piezoelectric. A first electrode is positioned in the first area, on the first surface, of the piezoelectric. A second electrode is positioned in the second area, on the first surface, of the piezoelectric. A third electrode is located on a second surface of the piezoelectric.

Abstract: A laminated piezoelectric transformer is provided using the longitudinal vibration modes for step-up voltage conversion applications. The input portions are polarized to deform in a longitudinal plane and are bonded to an output portion. The deformation of the input portions is mechanically coupled to the output portion, which deforms in the same longitudinal direction relative to the input portion. The output portion is polarized in the thickness direction relative its electrodes, and piezoelectrically generates a stepped-up output voltage.

Abstract: In accordance with one embodiment of the present application, a piezoelectric diaphragm structure includes a diaphragm, with a piezoelectric material located on the diaphragm. The piezoelectric material is being poled in a radial direction to the piezoelectric material, wherein the poling direction is in-plane with the piezoelectric material. An inter-digitated electrode grid is positioned on a first surface of the piezoelectric material, the inter-digitated electrode grid including a plurality of electrodes configured to selectively receive positive and negative voltage. The application of the positive and negative voltages generate electric fields in the piezoelectric material, at least a portion of which are in-plane with the piezoelectric material, resulting in an actuation of the piezoelectric material, causing a length change of the piezoelectric material in the Radial direction.

Abstract: A lead zirconate titanate-based thin film is an epitaxial crystal thin film and has a chemical composition represented by the general formula Pb1-xLnxZryTi1-yO3 (wherein Ln represents any one selected from the group consisting of lanthanum, lanthanoid elements, niobium, calcium, barium, strontium, iron, manganese and tin; and 0?x<1, 0.43?y?0.65) and whose orientation is {111} (including orientations whose tilt angle from the direction perpendicular to the substrate surface is within 15°).

Abstract: A piezoelectric transducer comprises a piezoelectric component, an acoustic member attached to one of the surfaces of the piezoelectric component and a dampening material of low elastic modulus attached to one or both surfaces of the piezoelectric transducer. The piezoelectric component may comprise either an unimorph or a bimorph structure including a piezoceramic wafer made of lead zirconate titanate and a layer of dampening material sandwiched between the piezoelectric component and the acoustic member. The acoustic member comprises a surrounding wall portion and an end portion which form an acoustic chamber when the member is mounted on a surface of the piezoelectrie component. The end portion has an orifice to form a passageway from the chamber through the end portion to the outside of the member.

Abstract: Inner individual electrodes are formed at intervals on a piezoelectric ceramic layer so as to correspond in a one-to-one relationship with ink channels, and an inner common electrode are formed on another piezoelectric ceramic layer. The required number of piezoelectric ceramic layers with inner individual electrodes and with an inner common electrode are laminated alternately. An outer common electrode is connected to the inner common electrodes, and outer individual electrodes are connected to the respective inner individual electrodes. The capacitance between the outer common electrode and each of the outer individual electrodes is measured. A polarization electric field adjusted based on the measured value is applied between the common electrode and each of the outer individual electrodes to perform polarization.

Abstract: A BAW resonator includes a first piezoelectric layer made of a material oriented toward a first direction, and a second piezoelectric layer made of a material oriented toward a second direction which is opposed to the first direction. The first piezoelectric layer and the second piezoelectric layer are acoustically coupled with each other.

Abstract: It is an object of the present invention to provide a piezoelectric actuator which uses strontium ruthenate as the material of the bottom electrode, and which uses PMN-PT as the material of the piezoelectric layer. This piezoelectric actuator comprises a base layer (31, 20) of SiO2 or Si ((100) orientation or (110) orientation), a buffer layer (41) constituted by strontium ruthenate (SRO), and a piezoelectric layer (44) constituted by a relaxor dielectric (PMN-PT) with a rhombohedral or quasi-cubic crystal structure oriented in the (001) direction at room temperature.

Abstract: In a gallium phosphate crystal, a crystallographic Y-axis and a Z-axis that have been rotated about an X-axis counterclockwise through an angle ? is referred to as a Y?-axis and a Z?-axis, respectively, where the angle ? is in a range from 10° to 20°. A piezoelectric crystal material made of gallium phosphate is provided as a plate-shaped member which is elongate in an X-axis direction and cut from the gallium phosphate crystal parallel to an X-Z? crystal plane of the gallium phosphate, and the plate-shaped member has sides parallel to an axis that is obtained by rotating the Y?-axis counterclockwise about the X-axis in an angular range from 1° to 3°.

Abstract: A surface acoustic wave device includes multiple SAW resonators formed on a piezoelectric substrate and connected in a ladder arrangement, the piezoelectric substrate having a polarization inverted region on which either a series-arm resonator or a parallel-arm resonator is formed.

Abstract: A thin film piezoelectric element including a first structure having a sequential stack of layers, a first main electrode layer, a first opposed electrode layer and a first piezoelectric thin film having a first polarizing direction located between the first electrode layers, a second structure having as a sequential stack of layers, a second main electrode layer, a second opposed electrode layer and a second piezoelectric thin film having a second polarizing direction located between the second electrode layers, an insulating resin layer covering peripheral portions of the first and second structures, and at least one connecting electrode pad located at a side of one of the first and second structures, for connecting the main electrode layer and the opposed electrode layer of the structures to external equipment, wherein each first and second structures has a cross-sectional shape such that the piezoelectric thin film is tapered, diminishing in width, from a portion near the main electrode layer to a portion

Abstract: A high frequency filter comprises thin film piezoelectric resonators connected in series between the input/output nodes, thin film piezoelectric resonators connected in parallel between the input/output nodes and a variable voltage circuit adapted to change the voltage applied to at least either the thin film piezoelectric resonators connected in series or the thin film piezoelectric resonators connected in parallel. The resonance characteristic of at least either the thin film piezoelectric resonators connected in series or the thin film piezoelectric resonator connected in parallel is shifted by changing the voltage applied by the variable voltage circuit to change the pass characteristic of the filter.

Abstract: A laminate type piezoelectric element having an improved piezoelectric property is provided. Vibration electrodes are arranged in a piezoelectric body, and high-order vibration of the thickness vibration is excited. The piezoelectric ceramic includes two ceramic piezoelectric layers which are laminated, and are integrally formed. Each of the ceramic piezoelectric layers contains ceramic crystal grains having shape anisotropy and spontaneous polarization preferentially oriented in one plane. The in-plane direction of this plane is perpendicular to the principal surfaces of the ceramic piezoelectric layers. The ceramic piezoelectric layers are polarized in the same thickness direction.

Abstract: A three-terminal filter using the area flexural vibration mode is smaller than filters using the area expansion vibration mode or the length vibration mode, and is easily adjusted to produce a desired frequency by changing the thickness and length of the three-terminal filter. The three-terminal filter includes three electrodes having a substantially square shape, and two piezoelectric layers having a substantially square shape, which are alternately laminated. The piezoelectric layers are polarized in the same thickness direction as the thickness direction, or in opposite thickness directions. The three-terminal filter further includes one surface electrode that functions as an input electrode, another surface electrode that functions as an output electrode, and an internal electrode that functions as a ground electrode.

Abstract: In a polarization method of the multi-layered piezoelectric body in which a plurality of piezoelectric layers and a plurality of internal electrodes are alternately laminated and adjacent piezoelectric layers are polarized in the thickness direction such that the polarized directions thereof are in opposite directions, a first polarization process in which an electric field in one direction is applied in the thickness direction to the multi-layered piezoelectric body and a polarization is uniformly performed in the thickness direction, and a secondary polarization process in which an electric field in the opposite direction is applied to the piezoelectric layers on both sides of one of the internal electrodes and the direction of polarization of only one of the piezoelectric layers on one side of the internal electrode is reversed are provided.

Abstract: A piezoelectric thin film resonator which comprises a first electrode, a second electrode, and a piezoelectric film which is interposed between the first electrode and the second electrode, and formed of an epitaxial ferroelectric thin film containing barium titanate, a spontaneous polarization of the epitaxial ferroelectric thin film being uniaxially orientated in a direction normal to a film surface.

Abstract: A piezoelectric type acceleration sensor which is small in size and has a high charge sensitivity and large static capacitance includes a piezoelectric element having a laminate of more than three piezoelectric layers. Electrodes are provided between the piezoelectric layers and the top and bottom surfaces of the laminate. The piezoelectric element is supported at opposed ends. Adjacent ones of the piezoelectric layers are polarized so that charge having the same polarity is accumulated at the electrode interposed the adjacent ones.

Abstract: A piezoelectric transformer including a piezoelectric body which includes a primary portion and a secondary portion, both the primary portion and the secondary portion being able to generate and transform piezoelectric vibrations in accordance with an AC Voltage fed to one portion while a transformed voltage can be delivered from the other portion, the piezoelectric body being constituted by a substantially annular body the primary and secondary portions of which have been polarized substantially perpendicular to the peripheral direction of the annular body, the transformer being adapted to be operated at a resonance frequency of a dimension of a cross-section of the annular body substantially perpendicular to the peripheral direction of the annular body.

Abstract: A method for making a piezoelectric composite transducer is disclosed. A block of piezoelectric material having a common base and a plurality of uniform-length rods is utilized. An electric conductor is positioned to extend through a side region of the block. Spaces between the rods are filled up to a first surface region with a viscoelastic material. The common base of the block is removed forming a second surface region. Electrodes are deposited at the first surface region to be in contact with the rods and in electrical contact with the electric conductors. A ground electrode is deposited at the second surface region to be in contact with the rods. The resulting piezoelectric composite transducer can be heated and shaped to conform to complex curves.

Abstract: There is provided a wireless-type power supply method that is applied to the case where an object to which energy is to be transmitted is relatively small, such as a micromachine, and that allows high-voltage electrical energy to be transmitted without using a wire. In this method, the optical energy from an light source is converted into high-voltage electrical energy by means of an energy transducer formed of either a piezoelectric element or a photovoltaic element on the above-described object, and the high-voltage electrical energy is supplied to an actuator, whereby the construction of the receiving side of the energy transmission is simplified.

Abstract: An acceleration sensor includes a piezoelectric element and support frames for supporting the ends of the piezoelectric element in the longitudinal direction. The piezoelectric element is formed by stacking an even number of piezoelectric layers greater than or equal to six layers. Electrodes are provided in between the layers and on the front and back faces of the piezoelectric element. The interlayer electrodes including segmented electrodes and lead electrodes are alternately stacked with the piezoelectric layers therebetween. The interlayer electrode in the middle in the thickness direction is a lead electrode. The piezoelectric layers are polarized in the thickness direction so that charge having the same polarity is extracted from the electrodes when an acceleration is applied. Also, the center portion and both end portions of each piezoelectric layer are polarized in opposite directions.

Abstract: The present invention relates to a multilayer piezoelectric transformer that uses a composite resonant vibration mode for step-up voltage conversion. More specifically, a multilayer piezoelectric transformer is provided using radial and shear vibration modes for step-up voltage conversion applications. Adjacent layers of piezoelectric ceramic act as a constraint on the deformation of one face of the input layers, leading to a gradient in the radial deformation of both the input and output portions. The piezoelectric transformer is used in a circuit for providing electro-luminescent (EL) backlighting.

Abstract: A multilayer piezoelectric transformer is provided using a composite vibration modes for step-up voltage conversion applications. An input portion polarized to deform radially is bonded to an output portion via a bondline or constraint layer. The deformation of the central face of the input portion is constrained by the bonded output layer or constraint layer. The output layer is bonded to the input layer or constraint layer and also deforms radially. The differing freedom of motion between the layers creates a gradient of stress and strain in the thickness direction resulting in large shear forces along the input and output layers. The composite radial-shear mode deformation of the output portion piezoelectrically generates an efficient, stepped-up high output voltage.

Abstract: Piezoelectric transformers have a number of favorable characteristics over traditional electromagnetic tranformers. However, the construction of piezoelectric transformers tends to be complicated, which may result in increasing manufacturing cost. Furthermore, such complex constructions may raise difficulties in the miniaturization of such devices. A ring-shaped piezoelectric transformer is developed in this invention for low voltage applications. One surface of the transformer is covered by two disc or ring-shaped electrodes separated by a ring-shaped separating segment, and the regions covered by the disc or ring-shaped electrodes served as the input and output parts of the transformer. This transformer may be fabricated relatively easily due to its simple structure. Furthermore, its size and thickness may be reduced relatively easily without increasing the difficulty of the fabricating process. The transformer may be used separately or in parallel.

Abstract: A polarization apparatus is provided wherein a piezoelectric body tube 3 is wound around a first rotation drum 5 and a second rotation drum 6 and a coaxial flexible piezoelectric body 2 is polarized while the piezoelectric body tube 3 is wound. According to the polarization apparatus, polarization can be conducted except for the coaxial flexible piezoelectric body 2 of the portion containing a defect and a defect existing in the piezoelectric body tube 3 of a given length can also be detected before an outer electrode 4 is formed.