Abstract: Deterioration of the Q value caused by the thermoelastic effect is suppressed. Since a first depth of a first groove and a second depth of a second groove are smaller than a distance between a surface including a third surface and a surface including a fourth surface, the first and second grooves do not penetrate between the surface including the third surface and the surface including the fourth surface. In addition, the sum of the first depth of the first groove and the second depth of the second groove is greater than the distance between the third and fourth surfaces, a heat transfer path between a first expandable portion (the first surface) and a second expandable portion (the second surface) cannot be formed as a straight line. As such, the heat transfer path between the first expandable portion (the first surface) and a second expandable portion (the second surface) is made to detour to the first and second grooves and and thus be lengthened.

Abstract: Devices having piezoelectric material structures integrated with substrates are described. Fabrication techniques for forming such devices are also described. The fabrication may include bonding a piezoelectric material wafer to a substrate of a differing material. A structure, such as a resonator, may then be formed from the piezoelectric material wafer.

Abstract: An integrated sensory actuator (10) which uses an electroactive polymer is provided. The sensory actuator is comprised of an actuating member (12) made of an ionic polymer-metal composite; a sensing member (14) made of a piezoelectric material; and an insulating member (16) interposed between the actuating member and the sensing member. The sensory actuator may further include a compensation circuit adapted to receive a sensed signal from the sensing member and an actuation signal from the actuating member and compensate the sensed signal for feedthrough coupling between the actuating member and the sensing member.

Abstract: A driving device includes an electro-mechanical transducer having first and second end portions opposite to each other in an expansion/contraction direction, a stationary member coupled to the first end portion of the electro-mechanical transducer, a vibration friction portion mounted to the second end portion of the electro-mechanical transducer, and a moving portion frictionally coupled to the vibration friction portion, whereby moving the moving portion in the expansion/contraction direction of the electro-mechanical transducer. The moving portion is driven by equalizing a constant expanding speed of the electro-mechanical transducer with a constant contracting speed of the electro-mechanical transducer and by setting a constant rest time interval after one of contraction of the electro-mechanical transducer and expansion of the electro-mechanical transducer.

Abstract: The invention relates to a device for changing the operational state of an apparatus, in particular from a stand-by or power down mode into an active state, which, in order to reduce power consumption during a stand-by mode and, furthermore, in order to reduce accidental powering up of the apparatus, comprises at least one means for transforming a mechanical excitation, in particular applied to the surface of the apparatus, into an electric signal and a power providing means for supplying at least a part of, in particular all, the electric power necessary to enable a change of the operational state of the apparatus wherein the electric power is obtained out of the electric signal. The invention, furthermore, relates to any apparatus comprising this device for changing operational state and a corresponding method.

Abstract: An ultrasonic probe has transmitting ultrasonic transducers and receiving ultrasonic transducers. The transmitting ultrasonic transducer is composed of a multilayer piezoelectric element, and the receiving ultrasonic transducer is composed of a single-layer piezoelectric element. The transmitting and receiving ultrasonic transducers are alternately arranged in an azimuth direction to form a piezoelectric element line. The single transmitting ultrasonic transducer and the single receiving ultrasonic transducer that adjoin to each other compose a single channel to transmit ultrasonic waves and receive echoes. The transmitting ultrasonic transducer is connected to a transmission circuit board on which a pulser is implemented, and the receiving ultrasonic transducer is connected to a reception circuit board on which an amplifier is implemented. The receiving ultrasonic transducer is directly connected to the amplifier without passing through a capacitance transmission line.

Abstract: A test substrate for measuring contact force and a method for measuring contact force are provided in the technology. The substrate may comprises: a base substrate, and a piezoelectric element provided on a surface of the base substrate. One end of the piezoelectric portion is a detecting voltage input terminal and the other end thereof is a detecting voltage output terminal. According to the technology, the substrate and method for measuring contact force can be used to measure the contact force applied to the substrate by the cleaning apparatus or conveying apparatus, and thus the contact force can be properly controlled and the adverse influence on the substrate from the conveying apparatus or cleaning apparatus can be decreased or eliminated.

Abstract: An oscillator circuit is described comprising a piezoresistive resonator and a phase changing devices. Oscillator circuits with piezoresistive resonators do have the advantage that they can perform self-sustaining oscillation without additional active devices as e.g. transistors since they can be used as amplifiers. Phase changing devices as capacitors, coils and further piezoresistive resonator are used in order to compensate the ?/2 phase shift of the piezoresistive resonator.

Abstract: A power supply device is disclosed that outputs a voltage of a wider range with a single piezoelectric transformer. The power supply device includes a piezoelectric transformer 101 for applying an output voltage to a transfer member that transfers a toner image formed on an image bearing member onto a recording material. The power supply device further includes a generation unit 110 configured to generate a driving frequency for driving the piezoelectric transformer 101. A control unit 701 controls a spurious voltage by changing driving frequency characteristics of the power supply device in accordance with a target value of an output voltage Vout.

Abstract: An angular velocity detection apparatus is disclosed. The angular velocity detection apparatus includes: a SAW angular velocity sensor; a synchronous detection unit configured to synchronously detect an output signal from the SAW angular velocity sensor by using a reference signal; and a switching signal generation unit. The switching signal generation unit cyclically switches on and off an input of a driving signal to the SAW angular velocity sensor, and switches on an input of the output signal to the synchronous detection unit when an unwanted wave is un-inputted to a sensing electrode of the SAW angular velocity sensor.

Abstract: A transducer for use with a boundary-stiffened panel has an inter-digitated electrode (IDE) and a piezoelectric wafer portion positioned therebetween. The IDE and/or the wafer portion are triangular, with one edge or side aligned with a boundary edge of the panel. The transducer generates and transmits an output force to the panel in response to an input voltage signal from a sensor, which can be another transducer as described above or an accelerometer. A controller can generate an output force signal in response to the input voltage signal to help cancel the input voltage signal. A method of using the transducer minimizes vibration in the panel by connecting multiple transducers around a perimeter thereof. Motion is measured at different portions of the panel, and a voltage signal determined from the motion is transmitted to the transducers to generate an output force at least partially cancelling or damping the motion.

Abstract: An electrical resonator device, capable of operating at variable frequency ?, including: an acoustic wave resonator, a first electrical circuit coupled in parallel to the resonator with an adjustable complex impedance whose imaginary part is equal to - j C 1 ? ? , where C1?0, a second electrical circuit coupled in parallel to the resonator and the first electrical circuit, with a complex impedance whose imaginary part is equal to - j C 2 ? ? , where C2<0, ? is the operating frequency of the device.

Abstract: Adaptive piezoelectric actuator control system, including: a power supply, a piezoelectric actuator, a driver driving the actuator, a signal generator providing a frequency signal to the driver, a user interface allowing user input of operating conditions, memory storing parameters of the actuator, and system control means controlling the power supply, driver generator and memory so operating frequency of the actuator is monitored and regulated, wherein the driver comprises test means providing a test signal to the actuator, voltage measurement means measuring voltage applied to the actuator caused by the test signal and voltage applied to the actuator caused by the frequency signal, the system control means receiving a response signal in response to the test, and receiving voltages measured by the voltage measurement means, and comprising signal analysis means creating a response signal envelope and controlling the generator to generate a frequency signal corresponding to the envelope maximum.

Abstract: Systems and methods for insuring successful initiation of a resonating micro-electro mechanical systems (MEMS). An example system includes a resonating sensor, a drive device, a charge amplifier, and a voltage gain circuit. At start up, the charge amplifier and voltage gain circuit receives signals from the resonating sensor, compensates this signal for DC offsets, and generates a clock signal for the drive, thus placing the resonating sensor in a steady state operating mode. The circuit includes a plurality of gain switches that are toggled to produce a glitch in the signal associated with the received signal. The glitch overcomes the DC offset. A comparator generates the clock signal for the drive device if a signal associated with the received signal exceeds a reference signal.

Abstract: With the aim of suppressing power consumption and reducing circuit size, a positive FET is turned on in accordance with a positive pulse signal and turned off when a return voltage rises up to a positive threshold. An active ground clamp circuit causes the output line to return to the ground voltage after the elapse of a predetermined period of time. A negative FET is turned on in accordance with a negative pulse signal and turned off when the return voltage falls down to a negative threshold. The active ground clamp circuit causes the output line to return to the ground voltage after the elapse of a predetermined period of time.

Abstract: An oscillation driver circuit includes a gain control amplifier which causes a vibrator to produce driving vibrations by controlling an oscillation amplitude in an oscillation loop, and a comparator which generates a synchronous detection reference signal based on a signal in the oscillation loop. The oscillation driver circuit sets a gain in a first oscillation loop including the vibrator and the comparator to be larger than unity using an output from the comparator, and then causes the vibrator to produce the driving vibrations by controlling an oscillation amplitude in a second oscillation loop including the vibrator and the gain control amplifier in at least one of an oscillation startup state and a sleep mode.

Abstract: Devices having piezoelectric material structures integrated with substrates are described. Fabrication techniques for forming such devices are also described. The fabrication may include bonding a piezoelectric material wafer to a substrate of a differing material. A structure, such as a resonator, may then be formed from the piezoelectric material wafer.

Abstract: A high gain pulse generator includes a piezoelectric transformer (PT) that is driven by an input power stage to drive the PT at a desired PT resonant frequency such that at least one PT characteristic substantially matches at least one non-linear load characteristic such as, without limitation, a plasma load characteristic to deliver a desired pulse to the non-linear load.

Abstract: In an embodiment, a device is provided comprising an accelerometer and an electroactive material. A control circuit is coupled between the accelerometer and the electroactive material.

Abstract: A single chip transducer apparatus that includes on-chip electronic circuitry which, when connected properly to a two-dimensional matrix of ultrasonic transducer elements, provides enough information to an external imaging system to form three-dimensional images of the subject of interest. In a preferred embodiment, the circuitry provides an amplifier for each transducer element, and then conditions the output of the amplifier in several ways. In one embodiment of the invention, the elements' analog voltages are stored in a sample and hold circuit, and time multiplexed into a high speed line driver that sends many elements data down the interconnect to the system's high speed Analog to Digital converters. In another embodiment, the gain of the amplifiers can be controlled in time to provide aperture translation and time based expansion for translating and focusing image slices in the elevation direction.

Abstract: The present invention discloses a DC/AC converter in the backlight power supply system using cold cathode fluorescent lamp (CCFL). The DC/AC converter comprises a front end DC/DC converter, a full-bridge or half bridge inverter, and a piezoelectric transformer. Even with a wide range of input voltages, the front end DC/DC converter produces a predetermined DC voltage or a DC voltage with a predetermined small range and the cascaded inverter operates with a switching frequency close to the resonant frequency of the piezoelectric transformer, which helps the backlight power supply system achieve high efficiency.

Abstract: A shock-activated switch device comprises a piezoelectric buzzer having a body for receiving a mechanical shock and a terminal for outputting an electrical output signal when the body receives a mechanical shock, and an output circuit connected to the terminal for converting the output signal into a logic signal for controlling an electronic circuit to execute a specific programmable function, such as alarm snooze.

Abstract: An efficient piezoelectric-triggered time delay module may be provided with separate firing and logic capacitors, and may also have corresponding separate piezoelectric transducers. Further, separate firing and logic capacitors may be impedance-matched to corresponding separate piezoelectric transducers. Optionally, the capacitors may be made of the same materials as the corresponding piezoelectric transducers. Further alternately or additionally, low-value, high-voltage rated capacitor(s) may be employed. Further alternately or additionally, the piezoelectric transducer(s) may be selected to offer high charge output within the intended operating temperature range. Further alternately or additionally, the piezoelectric transducer(s) may be constructed with multiple wafers.

Abstract: A phase-locked loop for controlling an electromechanical component comprises a digitally controlled oscillator (10), a phase comparator (20), and a digital loop filter (30). The digitally controlled oscillator (10) has an output (11), at which an oscillator signal (SOSC) can be picked up and which can be coupled to a first terminal (51) of the electromechanical component (50). The phase comparator (20) comprises a first input (21), which is coupled to the output (11) of the digitally controlled oscillator (10), and a second input (22), which can be coupled to the first terminal (51) or to a second terminal (52) of the electromechanical component (50) for feeding a current signal (S3). The digital loop filter (30) is connected between the phase comparator (20) and the digitally controlled oscillator (10).

Abstract: A surface-mount type crystal oscillator includes a container body with a recess, a first holding terminal and a second holding terminal provided in the recess, a crystal blank secured to the first and second holding terminals, and an IC chip including a first terminal and a second terminal on respective opposite sides of one end of the IC chip, the first and second terminals being used to electrically connect the amplification element within the IC chip to the crystal blank. In the recess, the first connection terminal is connected, by wire bonding, to one of a first circuit terminal connected to the first holding terminal and a second circuit terminal connected to the second holding terminal. The second connection terminal is connected, by wire bonding, to one of a third circuit terminal connected to the first holding terminal and a fourth circuit terminal connected to the second holding terminal.

Abstract: An efficient strain-inducing mechanism may be provided on the basis of a piezoelectric material so that performance of different transistor types may be enhanced by applying a single concept. For example, a piezoelectric material may be provided below the active region of different transistor types and may be appropriately connected to a voltage source so as to obtain a desired type of strain.

Abstract: Presented is a method of operating a capacitive microfabricated ultrasonic transducer (cMUT) array with multiple firings of varying bias voltage polarity patterns to improve its performance in imaging non-linear media, such as in contrast agent imaging or tissue harmonic imaging. Additionally, transducers incorporating the method are provided. The method of cMUT operation and the corresponding cMUT does not require pre-distortion or phase inversion of the transmit signal and can achieve an improvement in the elevation focus of the cMUT, as compared to the elevation focus that a single firing can achieve. Further, the method of operating the cMUT minimizes the deleterious effects that result from insulators being subjected to high electric fields.

Abstract: Disclosed is high efficiency power multiplying piezo transformer architecture having at least one piezo transformer assembly, the at least one piezo transformer assembly including of a plurality of piezo transformers circuits including a first outer and last outer piezo transformer circuits, each of the piezo transformer circuits having a primary side having a positive and negative electrode or terminal and a secondary side having a positive and a negative electrode or terminal. Each of the plurality of piezo transformer circuits forming the piezo transformer assembly is coupled to an adjacent piezo transformer circuit wherein the positive electrode of the primary side of each the piezo transformer circuit is coupled to a first node and each negative electrode of the primary side of each piezo transformer circuit is coupled to a second node.

Abstract: The present invention discloses a charging device for a portable electronic product with a charging circuit, including: a mechanical energy collecting device configured on a main body of the portable electronic product, adapted to collect and store part of mechanical energy of a user of the portable electronic product; a mechanical energy-electrical energy converting device coupled with the mechanical energy collecting device, adapted to convert mechanical energy stored by the mechanical energy collecting device into electrical energy; and a processing circuit connected between an output end of the mechanical energy-electrical energy converting device and an input end of the charging circuit of the portable electronic product, adapted to process energy output from the mechanical energy-electrical energy converting device and input processed energy to the charging circuit of the portable electronic product.

Abstract: A self-sensing dielectric actuator system. The system has a deformable dielectric material between two electrodes. A relatively low frequency actuating signal is applied to the electrodes and thereby causes the dielectric material to deform, moving at least one electrode. A relatively high frequency sensing signal applied across the electrodes indicates how far the electrode has moved. The system may be calibrated by using a laser or other sensor to mechanically measure the amount of movement. An object may be displaced a desired distance by coupling the object to the electrode and using the sensing signal to measure how far the object has moved.

Abstract: An integrated MEMS and IC system (MEMSIC), as well as related methods, are described herein. According to some embodiments, a mechanical resonating structure is coupled to an electrical circuit (e.g., field-effect transistor). For example, the mechanical resonating structure may be coupled to a gate of a transistor. In some cases, the mechanical resonating structure and electrical circuit may be fabricated on the same substrate (e.g., Silicon (Si) and/or Silicon-on-Insulator (SOW and may be proximate to one another.

Abstract: Embodiments of the acoustic galvanic isolator comprise a carrier signal source, a modulator connected to receive an information signal and the carrier signal, a demodulator, and an electrically-isolating acoustic coupler connected between the modulator and the demodulator. The electrically-isolating acoustic coupler comprises series-connected decoupled stacked bulk acoustic resonators (DSBARs).

Abstract: A piezoelectric element driving circuit includes: a transformer; a switch circuit; a reactance element connected in parallel with the piezoelectric element on one of the primary side and the secondary side of the transformer, the reactance element forming a resonant circuit that performs parallel resonance at the driving frequency with a capacitance component in an equivalent circuit of the piezoelectric element and an inductance component of the transformer; a pulse generating circuit for generating a driving pulse for the switch circuit; and a duty ratio controlling circuit for being supplied with the driving pulse, limiting a duty ratio of the driving pulse such that a value of the driving voltage falls within a range equal to or lower than the specification voltage value on the load side, and outputting the driving pulse whose duty ratio is limited to the switch circuit.

Abstract: A power supply apparatus including a current regulation unit configured to regulate a surge current generated on a primary side of a piezoelectric transformer. The surge current is generated when the piezoelectric transformer including a piezoelectric element and a holding unit, which are connected to each other using a conductive rubber, is driven.

Abstract: A device for the vibrational detection of a fill-level limit state and a process for the vibrational detection of a fill-level limit state The invention relates to a device for the vibrational detection of a fill-level limit state, and to a corresponding process, with a vibrational resonator (10), at least one piezoelement (11) that is loaded with a piezo-capacitance in order to induce a vibration in the vibrating resonator (10) by providing a drive frequency, and in order to detect a vibration in the vibrating resonator (10); two connecting conductors (12, 13) for the piezoelement (11), and circuit components (18-20) for evaluating a vibration in the vibrating resonator (10) detected by the piezoelement (11), where a branch with a compensating capacitor (2) is connected in parallel to a branch exhibiting the piezoelement (11) in order to compensate a recharging current in the piezoelement (11), which recharging current is dependent on the piezo-capacitance.

Abstract: A single chip transducer apparatus that includes on-chip electronic circuitry which, when connected properly to a two-dimensional matrix of ultrasonic transducer elements, provides enough information to an external imaging system to form three-dimensional images of the subject of interest. In a preferred embodiment, the circuitry provides an amplifier for each transducer element, and then conditions the output of the amplifier in several ways. In one embodiment of the invention, the elements' analog voltages are stored in a sample and hold circuit, and time multiplexed into a high speed line driver that sends many elements data down the interconnect to the system's high speed Analog to Digital converters. In another embodiment, the gain of the amplifiers can be controlled in time to provide aperture translation and time based expansion for translating and focusing image slices in the elevation direction.

Abstract: Disclosed herein is an apparatus. The apparatus includes a kinetic energy scavenger mechanism and a frequency tuning system. The kinetic energy scavenger mechanism is configured to harvest energy from a movement of a portable device. The kinetic energy scavenger mechanism includes at least one piezo member. The frequency tuning system is connected to the kinetic energy scavenger system. The frequency tuning system is configured to tune a harvesting frequency of the at least one piezo member based on, at least partially, a characterization of the movement of the portable device.

Abstract: A micro mechanical backscatter sensor includes a receiver for receiving a modulated electromagnetic signal, a capacitive element operatively connected to the receiver, the capacitive element being arranged such that a voltage is generated across the capacitor in response to the frequency of the received signal, and a resonator operatively connected to the capacitive element such that electrostatic forces that are induced by the voltage generated cause the resonator to vibrate at a resonance frequency, the resonator being arranged such that an applied external force alters the resonance frequency of vibration.

Abstract: A piezoelectric transformer driving circuit is provided which reduces switching losses in a full bridge circuit which drives a piezoelectric transformer. The piezoelectric transformer driving circuit has a full bridge circuit 1 comprising four FETs (field effect transistors) Q1 to Q4, a driving circuit 2 thereof, a filter circuit 3 which converts a square wave output from the full bridge circuit 1 into a sinusoidal wave, and one or a plurality of piezoelectric transformers 4 connected to the filter circuit 3. A cold cathode tube 5 serving as a backlight is connected to the secondary terminals of each of the piezoelectric transformers 4. In the filter circuit 3, an inductance L1 to adjust the current phase of the full bridge load is connected in parallel with the output of the full bridge 1 or the piezoelectric transformers 4.

Abstract: A single chip transducer apparatus that includes on-chip electronic circuitry which, when connected properly to a two-dimensional matrix of ultrasonic transducer elements, provides enough information to an external imaging system to form three-dimensional images of the subject of interest. In a preferred embodiment, the circuitry provides an amplifier for each transducer element, and then conditions the output of the amplifier in several ways. In one embodiment of the invention, the elements' analog voltages are stored in a sample and hold circuit, and time multiplexed into a high speed line driver that sends many elements data down the interconnect to the system's high speed Analog to Digital converters. In another embodiment, the gain of the amplifiers can be controlled in time to provide aperture translation and time based expansion for translating and focusing image slices in the elevation direction.

Abstract: A piezoelectric transistor including a substrate, such as a semiconductor substrate. The substrate may include a cavity and the cavity may be etched downward. A piezoelectric transistor may include piezoelectric material formed over the semiconductor substrate in a cantilever form, and may be elastically strained up and/or down. A piezoelectric transistor may include metal material electrically connected to the piezoelectric material by the piezoelectric effect, and metal wiring may supply voltage to piezoelectric material. Methods of fabricating the same are disclosed.

Abstract: An electronic device comprising a power source, a piezoelectric actuator A, and a drive control apparatus 100 for controlling the driving of the piezoelectric actuator, wherein the drive control apparatus 100 is provided with a drive circuit 111 for supplying a drive signal SDR to the piezoelectric element of the vibrating body 12, a phase difference detection means 120 for detecting the phase difference indicating the vibration state of the vibrating body 12, a comparison voltage setting circuit 133 for correcting the target phase difference to be the target for the vibration state, and a drive frequency setting means 140 for comparing the phase difference with the target phase difference; and the piezoelectric actuator A can be driven with high efficiency independent of the drive voltage by modifying the drive frequency of the drive signal SDR so that the phase difference approaches the target phase difference based on the results of the above comparison.

Abstract: A driving circuit converts a direct current (DC) power supply voltage into an alternating current voltage of a predetermined frequency. The alternating current voltage is applied to an electrical element and boosted by a voltage resonant circuit of the electrical element. Based on a change in input voltage of the electrical element and a frequency component of a feedback voltage corresponding to the output voltage of the electrical element, an input voltage monitoring circuit generates an optimal control signal, and, using the optimal control signal, adjusts the DC power supply voltage such that a step-down chopper circuit is switched on and off at a predetermined duty ratio.

Abstract: In an ultrasonic endoscope capable of being inserted into a body of a patient and imaging ultrasonic tomographic images, a frame rate in electronic radial scanning operation is improved. The ultrasonic endoscope includes: an ultrasonic transducer unit including plural ultrasonic transducers, each having a first electrode and a second electrode, for transmitting and receiving ultrasonic waves; a plurality of first interconnections each connected to the first electrodes of predetermined ultrasonic transducers; and a plurality of second interconnections each connected to the second electrodes of ultrasonic transducers having the first electrodes not connected to each other; wherein the ultrasonic transducer unit performs scanning operation by simultaneously transmitting the same number of ultrasonic beams in each of plural angle regions when selectively supplied with drive signals via the plurality of first interconnections and the plurality of second interconnections.

Abstract: A piezoelectric transducer device includes a receive signal path, a transistor and a piezoelectric transducer connected to a first terminal of the transistor. The device also includes a switch connected to a second terminal of the transistor, wherein the switch is adapted to selectively connect the second terminal of the transistor to a transmit signal or to a bias voltage; an output connected to a third terminal of the transistor, and adapted to receive a signal from the transducer when the switch is connected to the bias voltage, wherein the switch is not in the receive signal.

Abstract: A piezoelectric transformer driving apparatus and a piezoelectric transformer driving method, wherein even if there exists a variation between piezoelectric transformers, no unnecessary resonant points occur in the vicinity of a frequency used, that is, the output is stable for the frequency. For this purpose, the primary electrodes (1b, 2a) of a pair of piezoelectric transformers (1, 2) that exhibit potentials of mutually different signs on their respective secondary sides are connected to each other, while the piezoelectric transformers (1, 2) are connected in series with an AC power supply. An input voltage is applied between the primary electrodes (1a, 2b), and the outputs are supplied to a load, whereby even if there exists a variation between the vibrations of the piezoelectric transformers, it results in only a single resonant point existing.

Abstract: A signal line for an implantable electromedical configuration, having an electric line segment or line end and a mechanoelectric converter for converting an electric AC voltage signal into a mechanical oscillation. The oscillation can in turn be converted back into an electrical signal for delivery to a part of a human or mammal body, e.g., a heart.

Abstract: A tuning fork type piezoelectric vibrating piece, comprising: a base unit having a base electrode for an external connection; a fork shaped arm unit extending from the base unit; a groove portion at least on a surface or a rear surface of the arm unit; a groove electrode on the groove portion; a side surface electrode on the arm unit without the groove portion; a first electrode connecting the base unit and the side surface electrode or the groove electrode; a second electrode connecting the groove electrode and the side surface electrode; and a side surface electrode set at a predetermined distance from the bottom of the fork part of the base unit. The piezoelectric vibrating piece may be packaged with a base electrode connected to an external output terminal. The piezoelectric oscillator may have an amplifier circuit and a feedback circuit with a resonant element determining the resonant frequency.

Abstract: A power supply apparatus with a plurality of power supply circuits each having a piezoelectric transformer and a voltage-controlled oscillator which generates a signal at an operating frequency used to drive the piezoelectric transformer in accordance with a control signal, includes a frequency-dividing circuit which divides the operating frequency generated by a voltage-controlled oscillator in at least one power supply circuit, and outputs a signal at a driving frequency to drive a piezoelectric transformer in the one power supply circuit. When at least one power supply circuit and remaining power supply circuits output voltages, the operating frequency generated by the voltage-controlled oscillator in the one power supply circuit is controlled to be higher than the operating frequency generated by the voltage-controlled oscillator in another power supply circuit.

Abstract: A power supply unit in an image forming apparatus is provided. The power supply unit includes a piezoelectric transformer, an output voltage detecting circuit which detects the output voltage of the piezoelectric transformer, an output voltage control circuit which controls an output voltage from the piezoelectric transformer, and includes a comparator which receives an output voltage setting signal, together with an output voltage detecting signal fed back from the output voltage detecting circuit, to compare the output voltage setting signal and the output voltage detecting signal. The power supply unit also includes a driving frequency supplying circuit which generates a driving frequency signal of the piezoelectric transformer in accordance with a comparison result by the comparator, and supplies the driving frequency signal to the piezoelectric transformer. The time constant of the output voltage control circuit is longer than the time constant of the output voltage detecting circuit.