Abstract: A piezoelectric-transformer inverter includes a piezoelectric transformer for supplying a transformed voltage to a load connected to a secondary electrode thereof. A first coil and a first transistor are connected to one primary electrode of the piezoelectric transformer, and a second coil and a second transistor are connected to the other primary electrode of the piezoelectric transformer. The first and second transistors are alternately turned on and off such that the phase of the voltage applied between the primary electrodes is reversed cyclically. The operation frequency is controlled such that an AC current flowing through the load is maintained at a predetermined level. The piezoelectric transformer has a piezoelectric substrate. In a first half region of the piezoelectric substrate, a plurality of electrode films are layered in order to form the primary electrodes. The secondary electrode is formed on an end surface of the piezoelectric substrate opposite to the primary electrodes.

Abstract: A friction member is used in a friction portion in a vibration wave driving apparatus. The friction member comprises a composite resin which comprises polytetrafluoroethylene as a matrix and which further comprises at least an inorganic fiber substance and a heat-resistant resin. A ratio of a content Vf (vol %) of the inorganic fiber substance to a content Vr (vol %) of the heat-resistant resin satisfies the following relation: ⅓≦Vf/Vr≦3.

Abstract: A piezo-electric actuator operable in a fluid. The actuator has a piezo-electric element having one or more layers of piezo-electric material and electrodes adjacent to the piezo-electric material, the electrodes being coupled to electrical leads. A conductive layer surrounds the piezo-electric element, serving as a Faraday cage for shielding the fluid from effects due to electric fields within the conductive layer. A seal substantially impermeable to the fluid surrounds the piezo-electric element.

Abstract: A piezoelectric actuator assembly that is insensitive to wide variations in operating temperatures including a stack of piezoelectric devices and a surrounding housing assembly formed of an outer cylindrical housing portion formed of steel having a coefficient of thermal expansion above that of the piezoelectric material and an inner cylindrical housing portion formed of Si—Ni ceramic. By arranging the inner and outer housing portions in parallel and forming the housing portions with appropriate cross-sectional areas, the housing assembly will have an effective coefficient of thermal expansion &agr;e that is equivalent to that of the piezoelectric element &agr;p.

Abstract: An SAW device including a glass substrate, an LiNbO3 (LT) substrate, and an electrode. When a pitch of the electrode is &lgr;, a thickness of the LT substrate is H, and K equals to 2&pgr;/&lgr;, a product of K and H is at least 0.5 and at most 1.5. Accordingly, a SAW device which can advantageously reduced in size by a reduction in propagation velocity and which is provided with high K2 and an enhanced temperature characteristic as having a good temperature characteristic of the LT substrate.

Abstract: An SAW device including a glass substrate, an LiNbO3 (LN) substrate, and an electrode. When a pitch of the electrode is &lgr;, a thickness of the LN substrate is H, and K equals to 2&pgr;/&lgr;, a product of K and H is at least 1.6 and at most 1.8. Accordingly, a SAW device which can advantageously reduced in size and provided with an enhanced temperature characteristic is obtained while ensuring high K2.

Abstract: A piezoelectric switch comprising an end surface which when pressure is applied, causes a piezoelectric element to switch and generate an electrical signal. In addition, the piezoelectric element provides audible feedback to an operator activating the switch. The piezoelectric switch comprises a plastic housing having the piezoelectric element adhesively attached to an inside surface of a top portion of the housing. Two wires from the piezoelectric element connect to a printed circuit board which is placed adjacent to the piezoelectric element and wires from the printed circuit board extend through a cap for external connections. When the piezoelectric element switches, an output pulse having a predetermined pulse width is generated along with a signal which is fed back to trigger an oscillator connected to the piezoelectric element causing it to buzz, thereby providing audible feedback from the same piezoelectric element.

Abstract: A piezo actuator (1) is disclosed that has a contact lug (20, 21) for the electrical contacting of an electrode (14, 15) of an actuator member (11). Due to an expansion and contraction of the actuator member, a mechanical stress occurs in the contact lug that is minimized in that the contact lug has a device for adapting the expanse to a dimension of the expansion and contraction. The device is, for example, a deformation material in the form of a wire weave. The piezo actuator is utilized for the drive of an injection valve in an internal combustion engine.

Abstract: A method for regulating a generator is described in which the rectified output voltage furnished by the generator is converted, under certain preconditions, with the aid of a direct voltage converter. The generator can be operated either in a free operating mode or a regulated operating mode. If the generator voltage output in the particular operating state is not equivalent to the on-board electrical voltage, then the generator voltage is either raised or lowered with the aid of the voltage converter. The selection of the generator operating mode is done as a function of rpm or voltage, in such a way that the available generator power or energy conversion efficiency is as high as possible.

Abstract: Disclosed is a method and system for actively controlling the shape of a sheet of electroactive material; the system comprising: one or more electrodes attached to the frontside of the electroactive sheet; a charged particle generator, disposed so as to direct a beam of charged particles (e.g. electrons) onto the electrode; a conductive substrate attached to the backside of the sheet; and a power supply electrically connected to the conductive substrate; whereby the sheet changes its shape in response to an electric field created across the sheet by an accumulation of electric charge within the electrode(s), relative to a potential applied to the conductive substrate. Use of multiple electrodes distributed across on the frontside ensures a uniform distribution of the charge with a single point of e-beam incidence, thereby greatly simplifying the beam scanning algorithm and raster control electronics, and reducing the problems associated with “blooming”.

Abstract: An actuator device (2) includes a piezoelectric or electro-strictive solid state actuator element (6) that is elongated upon application of an electric voltage thereto, and a transmission mechanism (8) that amplifies the stroke displacement of the actuator element. The transmission mechanism (8) includes a plurality of rigid frame members (12), including unitary frame members (12.1, 12.2) and divided frame members (12.3), and elastically flexible joints (10) that respectively interconnect the frame members. Each one of the divided frame members (12.3) is made up of a plurality of separate parallel link rods (16). Each flexible joint (10) is made up of a plurality of individual parallel hinge members (18) that respectively connect an end of each one of the link rods (16) to the adjacent unitary frame member (12.1, 12.2).

Abstract: An improved piezoelectric resonator having multiple layers of material within each electrode of the resonator. One layer of material within each electrode is selected and used to increase the effective coupling coefficient between the piezoelectric layer of material in the resonator and the electric fields resulting from the voltages applied to the electrodes. The second layer of material within each electrode is selected and used to decrease the electrical losses within the electrodes.

Abstract: An ultrasonic transducer array element operating in the k31 mode is formed by two piezoelectric subelements joined to form a 2—2 composite by a conductive filler material. An energizing potential is applied to the conductive filler material, and a return potential is applied to the outer opposing faces of the subelements. Preferably the conductive filler material comprises a conductive epoxy. Arrays of such elements in one and two dimensions are formed with the conductive epoxy in alternating kerfs in a row being connected to the opposing polarities of an energizing potential.

Abstract: In a piezoelectric element having a laminated body 11 of piezoelectric layers, wherein an electric voltage is applied across internal electrodes 121 and 122 of positive and negative polarities formed between the layers from external electrodes 131 and 132 so as to form an electric field within the piezoelectric layers to thereby displace the piezoelectric layers, an inductor is provided at an intermediate position along a line connecting the external electrode of one polarity and the internal electrode 121 of the one polarity, whereby no inductor is needed in a driving circuit 7 even when there are provided numerous piezoelectric elements or a common piezoelectric element only has to be provided in the driving circuit which is common to the respective piezoelectric elements, thus making it possible to drive the piezoelectric elements with a simple driving circuit.

Abstract: Provided is a luminous element which utilizes a tribo-luminescence phenomenon. The luminous element comprises: a pressure luminous layer (14) which emits light upon the application of pressure; and a piezoelectric element which comprises a piezoelectric film (12) held between electrode films (11) and (13), and which is located so as to be capable of applying pressure on the pressure luminous layer.

Abstract: An ultrasonic motor drive apparatus includes a transformer having a primary coil and a secondary coil which drives a piezoelectric body of an ultrasonic motor. One end and the other end of the primary coil are connected to the drains of MOSFETS. The gates of the MOSFETs are connected to receive switching signals to alternately turn on and off electrical currents which flow in the primary coil. The sources of the MOSFETs are connected to the ground through ferrite beads, respectively. The ferrite bead generates a counter electromotive voltage so that the surge voltage which develops on the drain of the MOSFET at the time of turning off of the MOSFET is suppressed and high frequency oscillations are suppressed.

Abstract: A motor for use in magnetic fields generated for medical imaging. The motor comprises a stator. The stator includes a piezoelectric material and is configured to generate vibrations when subjected to a voltage gradient. A rotor is arranged and configured so that vibrations generated in the stator will propel the rotor. A drive shaft is connected to the rotor. The rotor and drive shaft are formed from a material that has a magnetic susceptibility that is about the same as the magnetic susceptibility of water.

Abstract: In a driving configuration for driving an actuator, component tolerances are compensated for by measuring a discharging current flowing in a measuring branch and the discharging voltage during a charge-transfer (reversing) operation. The measuring branch contains a series resonance circuit having a charging capacitor, a coil, an auxiliary switch and a measuring resistor. The current and voltage values measured at various instants are evaluated; and from them, initial parameters are determined for the subsequent driving operations.

Abstract: A piezoelectric thin film device which is composed mainly of a substrate, a piezoelectric thin film formed on the substrate, and thin film electrodes formed on both the upper and lower surfaces of the thin film. The thin film is resonated by applying an AC voltage across the electrodes. A substrate removed section is formed by partially or entirely removing the substrate below the thin film and opened to both the front and rear surfaces of the substrate through openings so as to relieve the pressure variation in the substrate removed section below a resonant structure.

Abstract: A surface acoustic wave device with electrodes having a metallization of a first layer of substantially pure titanium and a second layer of an alloy of aluminum and titanium. The titanium comprises about 0.1% to about 1.0% by weight of the alloy with aluminum substantially comprising the remainder of the alloy. The titanium of the first layer provides good adhesion and preferential Al(111) grain orientation for the second layer. The titanium of the second layer provides good mechanical strength for improved power handling while the aluminum maintains high electrode conductivity. Small grain structure in the metallization further improves mechanical strength.