Abstract: Disclosure of a novel accelerometer sensor method for detecting and measuring acceleration using paired radio frequency (RF) quartz crystal oscillators (QCO). Quartz crystal oscillators/resonators are known to be sensitive to acceleration or force impact events. Force impact events cause fluctuations in the quartz crystal resonator's natural resonant frequency. Normally this sensitivity to acceleration in QCOs is viewed as a negative property to be mitigated. This innovation exploits it in order to make a solid-state accelerometer with no mechanical parts. The crystalline structure of quartz crystal also has a preferred direction of maximum sensitivity to acceleration. There exists a mathematical relationship which relates these fluctuations in the resonator's natural frequency to the magnitude and direction of the accelerating source. Pairing acceleration sensitive QCO resonators will increase this sensor's sensitivity to acceleration.

Abstract: The present disclosure relates to a tunable Bulk Acoustic Wave (BAW) resonator with a top electrode, a bottom electrode, a piezoelectric layer sandwiched between the top electrode and the bottom electrode, and a reflection region underneath the bottom electrode. The reflection region includes a reflection layer and an ion-conductible structure between the bottom electrode and the reflection layer. Herein, the ion-conductible structure has a first terminal layer coupled to the bottom electrode, a second terminal layer coupled to the reflection layer, and an ion conductor between the first terminal layer and the second terminal layer. The ion conductor is eligible to transport ions between the first terminal layer and the second terminal layer, so as to achieve a mass-loading shift between the first terminal layer and the second terminal layer, and consequently, to tune a resonance frequency of the tunable BAW resonator.

Abstract: A quartz crystal resonator unit that includes a substrate, a lid, and an adhesive member that joins the substrate and the lid to each other to form an enclosure; a quartz crystal resonator disposed in the enclosure; and an adjustment member on the quartz crystal resonator and that includes a material whose volatilization amount per unit time and unit volume increases as humidity increases.

Abstract: A tunable capacitor that incorporates teachings of the subject disclosure may include: a substrate; a first dielectric layer over the substrate; a plurality of bias lines encapsulated between the substrate and the tunable dielectric layer; a first metal layer over the tunable dielectric layer (wherein the first metal layer has a plurality of first gaps); an upper bias layer over the first metal layer (herein each of a plurality of portions of the upper bias layer extend through a respective one of the plurality of first gaps to come into contact with the first dielectric layer, and wherein at least a second gap is disposed in the upper bias layer); and a second metal layer (wherein a portion of the second metal layer extends through the second gap to come into contact with the first metal layer). Other embodiments are disclosed.

Abstract: A semiconductor package structure includes an organic substrate having a first surface, a first recess depressed from the first surface, a first chip over the first surface and covering the first recess, thereby defining a first cavity enclosed by a back surface of the first chip and the first recess, and a second chip over the first chip. The first cavity is an air cavity or a vacuum cavity.

Abstract: A pressure detection device includes: a cylindrical body made of a conductor; a pressure receiver made of a conductor, the pressure receiver being mounted to one end side of the body and receiving pressure from the outside; a signal generator arranged inside the body, the signal generator being electrically connected to the pressure receiver and generating a signal corresponding to the pressure received by the pressure receiver; and a cover made of an insulator with a lower thermal conductivity than thermal conductivities of the body and the pressure receiver, the cover continuously covering an outer surface of the pressure receiver and a portion of an outer surface of the body, the portion being located at a side closer to the pressure receiver.

Abstract: A calibration system is provided for an oven controlled MEMS oscillator. The calibration system includes control circuitry that to separately selects predetermined target set-point values and controls a heater inside the oven controlled MEMS oscillator based on each of the selected target set-point values to adjust a set-point of the oven controlled MEMS oscillator. The system further includes an oscillation measurement circuit that measures respective oscillation frequencies at each adjusted set-point corresponding to each of the selected predetermined target set-point values. The measured oscillation frequencies can then be used to determine a target set-point operation value for the oven controlled MEMS oscillator, which can be sued to calibrate the oven controlled MEMS oscillator.

Abstract: An oscillator includes an oscillation circuit, an operation state signal generation circuit that generates an operation state signal based on an operation state of the oscillation circuit, and a first integrated circuit, the oscillation circuit and the operation state signal generation circuit are disposed outside the first integrated circuit, and the first integrated circuit includes a first digital interface circuit, a D/A conversion circuit that converts a digital signal input via the first digital interface circuit into an analog signal to generate a frequency control signal that controls a frequency of the oscillation circuit, and a terminal to which the operation state signal is input.

Abstract: A two-degree-of-freedom rotation control device includes a rotary body having a friction spherical surface, wherein a load mounting platform is provided on a top of the rotating body or inside the rotating body; a fixing and supporting structure configured to hold the rotating body, to allow the rotating body to have only a rotational degree of freedom; and a driving motor, wherein, a driving end of the driving motor is in direct contact with the friction spherical surface of the rotating body, to form a friction transmission pair tangent to the friction spherical surface. An application system has the two-degree-of-freedom rotation control device and a working unit on the two-degree-of-freedom rotation control device.

Abstract: An apparatus and method for a temperature and calibration utilizing resonant frequency peaks in an oscillator. A circuit providing resonant peaks for utilization for temperature measurements comprising a resonator device for providing an oscillating source, a variable gain-bandwidth amplifier in parallel with the crystal/resonator for providing modulation of the gain and/or bandwidth driving the crystal/resonator, and control of resonant peaks for selection for oscillation, a first capacitor electrically coupled to the parallel combination of the input of the variable gain-bandwidth amplifier, and the resonator device for providing charge storage for oscillation, and a second capacitor electrically coupled to parallel combination of the output of the variable gain-bandwidth amplifier, and the resonator device for providing charge storage for oscillation.

Abstract: A piezoelectric vibrating piece includes a vibrating piece body including a vibrator and at least one pair of excitation electrodes formed on a front surface and a back surface of the vibrator. The vibrating piece body is a twice rotated quartz-crystal vibrating piece. The pair of excitation electrodes are arranged in a Z??-axis direction determined by an X??-axis and obliquely disposed with respect to the Y?-axis direction. The X??-axis is rotated by 260° to 300° counterclockwise about a Y?-axis using a +X?-axis direction as a reference. The pair of excitation electrodes are formed to have respective semicircle shapes including straight line portions extending in the X??-axis direction and to be disposed in a state where the straight line portions overlapping with one another. The straight line portion of the excitation electrode includes an inclined portion that gradually decreases in thickness toward an end portion of the excitation electrode.

Abstract: A piezoelectric vibrating piece includes a vibrating piece body and at least a pair of excitation electrodes. The vibrating piece body includes a vibrator. The pair of excitation electrodes are formed on respective front surface and back surface of the vibrator. The vibrating piece body is a twice rotated quartz-crystal vibrating piece cut out parallel to an X?-Z? surface. The X?-Z? surface is rotated around a Z-axis of a crystallographic axis of a crystal and further rotated around an X?-axis. The pair of excitation electrodes are collocated in a Z??-axis direction determined by an X??-axis. The X??-axis is defined by counterclockwise rotation from a +X?-axis direction around a Y?-axis by 260° to 300°. The pair of excitation electrodes are disposed inclined with respect to the Y?-axis direction.

Abstract: A method for stabilizing the clock frequency of a microcontroller associated with a field device of automation technology. The field device as a function of application is exposed to different process conditions, wherein the clock frequency of the microcontroller is ascertained at least two different temperature values, and/or at least two different voltage values. Based on the ascertained values, the dependence of the clock frequency of the microcontroller on temperature over a predetermined temperature- and/or frequency range and/or the dependence of the clock frequency of the microcontroller on voltage over a predetermined voltage- and/or frequency range is ascertained. The ascertained values are stored, and the influence of temperature and/or voltage on the clock frequency of the microcontroller is at least approximately compensated taking into considering the ascertained temperature dependence and/or the ascertained voltage dependence.

Abstract: Provided is a friction drive actuator that is resistant to contamination of, for example, extraneous matter. An ultrasonic actuator according to an aspect of the present invention drives a columnar insertion section and includes a columnar vibrating body (40), whose distal end is pressed against a side surface of the insertion section, and a piezoelectric element (44), an upper electrode (44a), and a lower electrode (44b) that are provided at one side surface of the vibrating body.

Abstract: The present disclosure relates to a method that includes calculating a first frequency drift associated with an oscillator at a current temperature; based on the calculation, generating a first signal indicative of temperature compensation data; generating a second signal indicative of packet data and a modulation scheme; using the first signal, the second signal, and a first predetermined signal to generate a first tuning signal; and using the first tuning signal to tune a first capacitor array coupled to the oscillator and a second tuning signal to tune a second capacitor array coupled to the oscillator such that (i) the oscillator generates a modulated RF signal indicative of the packet data and (ii) the modulated RF signal has a second frequency drift that is less than a threshold.

Abstract: An ultrasonic motor comprising a rotor (18) having an at least partly spherical shape and two actuators (2, 2?) each comprising an element of plate-shaped piezoelectric material comprising at least one contact edge (4, 4?) in contact with the rotor (18), said actuators (2, 2?) also comprising on one of their faces electrodes intended to bias piezoelectric materials in a bending mode and in a longitudinal mode. The contact edges (4, 4?) are concave and are formed by an arc of circle the radius of which substantially corresponds to the radius of the surface of the rotor (18), said arcs of circle angularly extending at a determined angle such that the bending mode and the longitudinal mode in which the piezoelectric material is biased are at the same frequency.

Abstract: There is provided a DC power source apparatus that can prevent failures in components included in the DC power source apparatus and a load and that can prevent damage to or deterioration in the components. A control unit of the DC power source apparatus includes a function of limiting a duty value that is the ratio of an on-time to the switching period of a switching device, and makes an upper limit value for limiting the upper limit of the duty value variable during switching operation of the switching device.

Abstract: A vibration sensor includes a piezoelectric crystal; and a base having an upper surface and a lower surface, the piezoelectric crystal attached to the upper surface of the base, the base defining a notch in at least one of the upper surface and the lower surface. Another embodiment of a vibration sensor includes a first piezoelectric crystal; a second piezoelectric crystal; a base attached to the first piezoelectric crystal on first side of the base and attached to the second piezoelectric crystal on a second side of the base opposite the first side of the base; a voltage amplifier in electrical communication to the first piezoelectric crystal; and a charge amplifier in electrical communication to the second piezoelectric crystal.

Abstract: A resonation device includes substrate, a resonation element that is attached to first main surface of substrate at first and second attachment portion, and heat-generating unit that is disposed on second main surface which is side opposite to first main surface so as to overlap with resonation element in a planar view. When an angle formed by line which connects center of resonation element and center of first attachment portion and virtual line which connects center of heat-generating unit and center of resonation element in a planar view is ?1 and an angle formed by a line which connects center of resonation element and center of second attachment portion and virtual line which connects center of heat-generating unit and center of resonation element in a planar view is ?2, conditions 0°<?1<90°, 0°<?2<90°, and 0°<|?1??2|<10° are satisfied.

Abstract: An optical device with a deformable membrane including an anchor area on a support entrapping a liquid or gas fluid, a central area reversibly deformable from a rest position, actuating means for moving the fluid biasing the membrane into an intermediate area between the anchor area and the central area, the actuating means include a piezoelectric continuous crown accommodating several actuators, this crown surrounding the central area, the actuating means being anchored to the membrane in the intermediate area, the actuating means and the membrane to which they are anchored, forming at least one piezoelectric bimorph, the actuating means radially contracting or extending upon actuation to generate a movement of said fluid from the intermediate area to the central area of the membrane or vice versa, aiming at deforming the central area with respect to its rest position.

Abstract: System for producing a system clock signal comprising a local oscillator configured to generate a first clock signal; a temperature detector configured to detect a temperature change above a critical value in an area including the local oscillator; an obtaining module configured to obtain a second clock signal; a clock generator configured to generate the system clock signal in a first manner, using the first clock signal, in a normal mode when the temperature detector does not detect a temperature change above the critical value, and in a second manner different from the first manner, using the second clock signal, in a reverse hold-over mode when the temperature detector has detected a temperature change above the critical value.

Abstract: A system for driving a piezoelectric load includes a direct current (DC) voltage source and a bi-directional DC-to-DC converter having a primary side coupled to the DC voltage source and a secondary side and comprising a control input configured to receive a first control signal configured to control conversion of a first voltage on the primary side of the bi-directional DC-to-DC converter to a second voltage on the secondary side of the bi-directional DC-to-DC converter. The driver system also includes a capacitor coupled to the secondary side of the bi-directional DC-to-DC converter and configured to remove a DC offset of the second voltage and includes a reactive load having a first terminal coupled to the capacitor and a second terminal coupled to the secondary side of the bi-directional DC-to-DC converter.

Abstract: A boost converter device includes a converter, a current sensor which detects a reactor current flowing through a reactor, and a control unit which controls the converter by using feedback control of the reactor current. The control unit executes at least one of reducing a carrier frequency which is used in the control of the converter and reducing a duty command value which is used in the control of the converter, detects an amplitude of current ripple by the current sensor during execution of the reduction of the carrier frequency or the reduction of the duty command value, and detects the current sensor as being abnormal in a case where the amplitude of the current ripple is less than a predetermined current fluctuation range at the time of abnormality of the current sensor.

Abstract: There is provided a liquid jetting apparatus including: a first channel structure; a piezoelectric actuator provided on the first channel structure; and a driving device. The piezoelectric actuator includes: a vibration plate; a plurality of piezoelectric elements each including an activator formed of a piezoelectric material; signal input portions which receive drive signals for driving the plurality of piezoelectric elements from the driving device; a reference potential portion; and actuator wires. The piezoelectric elements include a first and second piezoelectric elements, a length of a wire which connects the first piezoelectric element and the driving device is longer than a length of a wire which connects the second piezoelectric element and the driving device, a capacitor is serially connected to the first piezoelectric element, and the capacitor includes an insulator formed of a piezoelectric material same as the piezoelectric material of the activators of the piezoelectric elements.

Abstract: A temperature compensated Micro Electro Mechanical (MEMS) oscillator is provided. The oscillator includes a MEMS resonator group, a heating device, a connection body, and a controller. The MEMS resonator group includes a first MEMS resonator and a second MEMS resonator. The first MEMS resonator is configured to output a main oscillation frequency. The second MEMS resonator is configured to output an auxiliary oscillation frequency according to a temperature of the second MEMS resonator. The heating device is configured to increase a temperature of the MEMS resonator group. The connection body is connected between the MEMS resonator group and the heating device to transmit heat from the heating device to the MEMS resonator group, and configured to electrically isolate the MEMS resonator group from the heating device. The controller is configured to control the heating device according to a difference between the main oscillation frequency and the auxiliary oscillation frequency.

Abstract: An optical device with a deformable membrane (2) including an anchor area (2.3) on a support (1) entrapping a liquid or gas fluid, a central area (2.1) reversibly deformable from a rest position, actuating means for moving the fluid (4) biasing the membrane (2) into an intermediate area between the anchor area (2.3) and the central area (2.1), the actuating means include a piezoelectric continuous crown accommodating several actuators (5.1), this crown surrounding the central area (2.1), the actuating means (5) being anchored to the membrane (2) in at least the intermediate area (2.2), the actuating means (5) and the membrane (2) to which they are anchored, forming at least one piezoelectric bimorph (B), the actuating means (5) radially contracting or extending upon actuation so as to generate a movement of said fluid (4) from the intermediate area (2.2) to the central area (2.1) of the membrane (2) or vice versa, aiming at deforming the central area (2.1) with respect to its rest position.

Abstract: A crystal unit is provided with a rectangular substrate, a frame which is provided on an upper surface of the substrate, a mounting frame which has joining pads which are provided along the outer circumferential edge of the upper surface and which is provided on the lower surface of the substrate by joining terminals provided along the outer circumferential edge of the lower surface of the substrate and its joining pads, a crystal element which is mounted on electrode pads which are provided on the upper surface of the substrate in a region surrounded by the frame, a thermosensitivel element which is mounted on connection pads which are provided on the lower surface of the substrate in a region surrounded by the mounting frame, and a lid which is joined to the upper surface of the frame.

Abstract: Methods, systems, and devices for providing cooling for a mobile device using piezoelectric active cooling devices. Some embodiments utilize piezoelectric actuators that oscillate a planar element within an air channel to fan air within or at an outlet of the air channel. The air channel may be defined by at least one heat dissipation surface in thermal contact with components of the mobile device that generate excess waste heat. For example, the air channel may include a surface that is in thermal contact with a processor of the mobile computing device. In embodiments, the piezoelectric active cooling device may be used in an air gap between stacked packages in a package on package (PoP) processor package. The described embodiments provide active cooling using low power, can be controlled to provide variable cooling, use highly reliable elements, and can be implemented at low cost.

Abstract: A MEMS resonator has a component which provides a capacitance associated with the transduction gap which has a temperature-dependent dielectric characteristic, which varies in the same direction (i.e. the slope has the same sign) as the Young's modulus of the material of the resonator versus temperature. This means that the resonant frequency is less dependent on temperature.

Abstract: An electric compressor controller includes a compressor that compresses refrigerant of an air conditioning system; a motor that drives the compressor; an inverter that selectively control switching elements based on PWM pulse signals to supply drive power to the motor and heats the refrigerant by heat generated due to switching of the switching elements during a heating operation; temperature detectors each detects junction temperature of each of the switching elements; a drive controller that supplies the pulse signals to the inverter to control the inverter; and a slope varying unit that variably controls precipitous degree of rising/falling slope waveforms of the pulse signals based on the junction temperature detected by the temperature detectors. According to the electric compressor controller, efficiency for heating refrigerant is improved, so that its own heating ability is improved.

Abstract: Various embodiments are directed to an apparatus and method of driving an end effector coupled to an ultrasonic drive system of a surgical instrument. The method comprises generating at least one electrical signal. The at least one electrical signal is monitored against a first set of logic conditions.

Abstract: A periodic signal generator is configured to generate high frequency signals characterized by relatively low temperature coefficients of frequency (TCF). A microelectromechanical resonator, such as concave bulk acoustic resonator (CBAR) supporting capacitive and piezoelectric transduction, may be geometrically engineered as a signal generator that produces two periodic signals having unequal resonant frequencies with unequal temperature coefficients. Circuitry is also provided for combining the two periodic signals using a mixer to thereby yield a high frequency low-TCF periodic difference signal at an output of the periodic signal generator.

Abstract: A quartz crystal vibrator includes a quartz crystal resonator element, a thermistor adapted to detect the temperature, and a package adapted to incorporate the quartz crystal resonator element and the thermistor, a plurality of electrode pads adapted to support the quartz crystal resonator element is disposed on an inner bottom surface of the package, to which the quartz crystal resonator element and the thermistor are installed, and a wiring pattern, which is extracted from at least one electrode pad, and has a thermal conductivity higher than a thermal conductivity of a package base of the package including the inner bottom surface, overlaps the thermistor in a plan view.

Abstract: The invention relates to a device for compensating influence of temperature on a resonator circuit. The device comprises a resonator circuit and a supply unit for supplying an electric bias signal to the resonator circuit, wherein the supply unit is adapted for adjusting the electric bias signal for compensating influence of temperature on the resonator circuit.

Abstract: A periodic signal generator is configured to generate high frequency signals characterized by relatively low temperature coefficients of frequency (TCF). This generator may include an oscillator containing a pair of equivalent MEMs resonators therein, which are configured to support bulk acoustic wave and surface wave modes of operation at different resonance frequencies. Each resonator includes a stack of layers including a semiconductor resonator body (e.g., Si-body), a piezoelectric layer (e.g., AIN layer) on the resonator body and interdigitated drive and sense electrodes on the piezoelectric layer. The oscillator is configured to support the generation of first and second periodic signals having unequal first and second frequencies (f1, f2) from first and second resonators within the pair. These first and second periodic signals are characterized by respective first and second temperature coefficients of frequency (TCf1, TCf2), which may differ by at least about 10 ppm/° C.

Abstract: A temperature-compensated oscillator includes a temperature compensation circuit adapted to output a temperature compensation voltage, a voltage-controlled oscillation circuit on which temperature compensation is performed based on the temperature compensation voltage, a switch circuit adapted to perform ON/OFF control on power supply to the temperature compensation circuit, and a sample-and-hold circuit adapted to perform switching control between an ON state of outputting the temperature compensation voltage to the voltage-controlled oscillation circuit while being connected to the temperature compensation circuit and holding the temperature compensation voltage output from the temperature compensation circuit when the power is supplied to the temperature compensation circuit, and an OFF state of outputting the temperature compensation voltage held to the voltage-controlled oscillation circuit while cutting connection to the temperature compensation circuit when the power supply to the temperature compensat

Abstract: A controller controls switching of IGBT devices of an inverter according to the desired output of the permanent magnet motor. The controller includes: a magnet temperature detection device that detects the magnet temperature of the permanent magnet motor based on the output of a temperature sensor; a setting device that sets a threshold value of the magnet temperature corresponding to the desired output of the permanent magnet motor, based on a predetermined relation between the output from the permanent magnet motor and a critical temperature, up to which demagnetization in the permanent magnet motor is not caused; and a carrier frequency control device that, when the magnet temperature detected by the magnet temperature detection device exceeds the threshold value, changes the carrier frequency, at which the IGBT devices are switched, such that a ripple current superimposed on a motor current that flows through the permanent magnet motor is reduced.

Abstract: A piezoelectric actuator unit includes a piezoelectric layer, a first electrode and a second electrode which are arranged to be sandwiching the piezoelectric layer, and which form an active portion of the piezoelectric layer by sandwiching the piezoelectric layer, a capacitor which is connected in series to the active portion, and a voltage applying mechanism which applies a first voltage to the capacitor, and a second voltage between the first electrode and the second electrode to cause a piezoelectric deformation in the active portion of the piezoelectric layer.

Abstract: A single element of an ultrasonic transducer includes at least one combination of an equivalent series capacitor C1, an equivalent series inductor L1, and an equivalent series resistance R1. The ultrasonic transducer further includes an equivalent parallel capacitor C0. An inductor L2 is connected in series between the ultrasonic transducer and the drive circuit. A first resonance frequency of the equivalent series capacitor C1 and the equivalent series inductor L1 is F0. A second resonance frequency determined by at least the equivalent parallel capacitor C0 and the inductor L2 is Fp. A drive circuit drives the ultrasonic transducer while switching the driving frequency of the ultrasonic transducer to one of the resonance frequency F0 and the resonance frequency Fp.

Abstract: A piezoelectric actuator unit includes a piezoelectric layer, a first electrode and a second electrode which are arranged to be sandwiching the piezoelectric layer, and which form an active portion of the piezoelectric layer by sandwiching the piezoelectric layer, a capacitor which is connected in series to the active portion, and a voltage applying mechanism which applies a first voltage to the capacitor, and a second voltage between the first electrode and the second electrode to cause a piezoelectric deformation in the active portion of the piezoelectric layer.

Abstract: A driving apparatus includes a piezoelectric element which undergoes expansion/contraction motion by a driving signal; a driving shaft which is mounted on the piezoelectric element, and undergoes reciprocating movement according to the expansion/contraction motion of the piezoelectric element; a first movement member which is friction-engaged with the driving shaft, and moves due to the reciprocating movement of the driving shaft; and a first control portion which applies driving signals to the piezoelectric element; the first control portion applies driving control pulse signals when the first movement member is to be moved, and applies stop control pulse signals when the stopped first movement member is not to be moved to put the first movement member into a vibration-arrested state. By this means, the stopped first movement member can be smoothly moved, and the first movement member in motion can be smoothly stopped.

Abstract: The present invention provides a fuel injector, comprising a housing having a sealable injector seat; a fuel injector pin disposed within the housing proximate to the injector seat such that the injector seat may be sealed and unsealed by displacing the fuel injector pin; a resilient element biasing the fuel injector pin in an unsealed direction; a piezoelectric actuator disposed within the housing proximal to the fuel injector pin configured to actuate to force the injector pin towards the injector seat to seal the injector seat; and a thermal compensating unit disposed within the housing proximal to the actuator and configured to compensate for thermal expansion or contraction of a component of the fuel injector.

Abstract: An oven controlled crystal oscillator includes a thermostatic bath, an inner circuit board, an outer circuit board, a heating element, and a temperature sensor. The inner circuit board comprising a crystal oscillation circuit is positioned inside the thermostatic bath and electrically connected with the outer circuit board via a pin. The outer circuit board has a temperature control circuit and a power supply circuit. The heating element and the temperature sensor electrically connect with the outer circuit board. A through slot is formed through the outer circuit board, and the thermostatic bath is inserted into the through slot. By inserting the thermostatic bath into the through slot of the outer circuit board, the height and the weight of the oven controlled crystal oscillator are reduced, the electric connection performance is enhanced, and thus the stability of the output frequency of the oven controlled crystal oscillator is improved.

Abstract: A piezoelectric device is provided with a sound source IC, an amplifier for amplifying a sound source from the sound source IC, a piezoelectric speaker for generating sound based on a drive signal from amplifier, an MPU for performing a predetermined control process on the drive signal, a memory for storing temperature dependency information about the piezoelectric constant (d14) and Young's modulus E of the piezoelectric speaker, and a temperature sensor for detecting an ambient temperature. MPU has correcting unit, compares a detected result of the temperature sensor with the temperature dependency information, and performs temperature correction on the drive signal serving as an acoustic signal based on a compared result. The piezoelectric speaker outputs the acoustic signal temperature-corrected by correcting unit.

Abstract: Disclosed herein is an ultrasonic sensor including: a conductive case; a piezoelectric element fixed to a bottom surface of the case through a conductive adhesive; a temperature compensation capacitor positioned on the piezoelectric element; a first lead wire and electrically connected to one surface of the temperature compensation capacitor; a first wire electrically connecting one surface of the temperature compensation capacitor and the case to each other; a second lead wire and electrically connected to the other surface of the temperature compensation capacitor; a second wire electrically connecting the other surface of the temperature compensation capacitor and an upper surface of the piezoelectric element to each other; and a fixing part fixing the first lead wire and the first wire to one surface of the temperature compensation capacitor and fixing the second lead wire and the second wire to the other surface thereof.

Abstract: In a SAW oscillator, each of a first SAW element and a second SAW element includes interdigital electrodes and a reflector formed on a piezoelectric material. A first oscillating circuit part forms an oscillating loop including the first SAW element. A second oscillating circuit part forms an oscillating loop including the second SAW element. The first and second oscillating circuit parts have an identical admittance property. The first and second SAW elements are configured that an electrode pitch is identical and an admittance property indicating a relation between a frequency and an admittance value is different therebetween. Further, a first intersection point between the admittance property of the first SAW element and the admittance property of the first oscillating circuit part and a second intersection point between the admittance property of the second SAW element and the admittance property of the second oscillating circuit part are at different frequencies.

Abstract: Disclosed herein is an ultrasonic sensor including: a case including an inner space formed therein; a substrate seated on a bottom surface of the case in the inner space thereof and including a plurality of piezoelectric elements and temperature compensation capacitors mounted in a row therein; and a sound absorbing material mounted on an upper portion of the substrate.

Abstract: Disclosed herein are an ultrasonic sensor and a method of manufacturing the same. The ultrasonic sensor includes: a conductive case; a piezoelectric element fixed to a bottom. surface of the case through a conductive adhesive; a temperature compensation capacitor positioned over the piezoelectric element; a first lead wire lead from the outside of the case and electrically connected to one surface of the temperature compensation capacitor and the piezoelectric element; a second lead wire lead from the outside of the case and electrically connected to the other surface of the temperature compensation capacitor and the case; and a first molding part closely adhered to outer portions of the temperature compensation capacitor and the first and second lead wires.

Abstract: Disclosed herein is an ultrasonic sensor, including: a conductive case having at least one groove disposed on a bottom surface thereof; a piezoelectric element fixed to the bottom surface of the case through a non-conductive adhesive; a conductive adhesive injected into the groove to electrically connect the case to the piezoelectric element; a temperature compensation capacitor disposed on an upper portion of the piezoelectric element; a first lead wire led-in from the outside of the case and being electrically connected to one surface of the temperature compensation capacitor and the piezoelectric element; and a second lead wire led-in from the outside of the case and being electrically connected to the other surface of the temperature compensation capacitor and the case.

Abstract: A temperature compensated crystal oscillator includes an oscillation circuit including a crystal oscillator; a variable capacitor inserted in series in the oscillation circuit; a thermosensitive circuit element whose resistance value changes in accordance with a temperature of the crystal oscillator, the thermosensitive circuit element being formed on the crystal oscillator by vapor deposition; and a correction circuit configured to correct capacitance of the variable capacitor based on a current value that is used when applying current to the thermosensitive circuit element.