Abstract: A capacitive load drive circuit includes a modulation circuit adapted to pulse-modulate a drive waveform signal to thereby generate a modulation signal, two switching elements (transistors) constituting a push-pull circuit and adapted to generate a power-amplified modulation signal, a low-side driver and a high-side driver adapted to switch ON/OFF of the respective switching elements, a bootstrap circuit, a power supply adapted to supply the low-side driver and the high-side driver with a predetermined electrical potential, and a first resistor disposed in a supply channel from the power supply to the bootstrap circuit.

Abstract: A liquid jet apparatus according to the present invention includes a drive waveform generator adapted to generate a drive waveform signal, a modulator adapted to execute pulse modulation on the drive waveform signal, a digital power amplifier adapted to power-amplify the modulated signal, on which the pulse modulation is executed by the modulator, with a pair of switching elements push-pull coupled with each other, a low pass filter adapted to smooth the amplified digital signal obtained by the power-amplification of the digital power amplifier, and a modulation period modification circuit adapted to modify a modulation period of the pulse modulation of the modulator based on data of the drive waveform signal.

Abstract: A power generation unit includes: a deformation member which is deformed by switching a deformation direction; a piezoelectric element which is installed to the deformation member; a pair of electrodes which are installed to the piezoelectric element; an inductor which is installed between the pair of the electrodes and which together with a capacitive component of the piezoelectric element constitutes a resonance circuit; a switch which is connected in series to the inductor; a full bridge rectifier which is installed between the pair of the electrodes to rectify an AC current generated by the piezoelectric element; a voltage detection circuit which detects potentials of an anode and cathode of a diode included in the full bridge rectifier; and a controller which allows the switch to be in an ON state for a predetermined time interval based on an output signal of the voltage detection circuit.

Abstract: A fluid ejection device includes a modulator adapted to pulse-modulate a drive waveform signal forming a basis of a drive signal of an actuator to obtain a modulated signal; a digital power amplifier circuit adapted to power-amplify the modulated signal to obtain a power-amplified modulated signal; a low pass filter adapted to smooth the power-amplified modulated signal to obtain the drive signal; and a power amplification stopping section operating when holding a voltage of the actuator constant.

Abstract: A power generating device which includes a transformation member that is transformed by receiving a transformation force in a transformation direction, a first piezoelectric device that is disposed on the transformation member, a second piezoelectric device that is disposed on the transformation member, an inductor comprising a resonance circuit including the first piezoelectric device, a switch that is disposed in the resonance circuit, and a control unit that controls the switch to be in a conductive state for a predetermined period by detecting a voltage generated in the second piezoelectric device as the second piezoelectric device is transformed in response to the transformation force being applied to the transformation member.

Abstract: A power generating device includes: a piezoelectric member that is formed from a piezoelectric material; one pair of electrodes that are installed to the piezoelectric member; a transformation unit that repeatedly transforms the piezoelectric member; an inductor that is installed between the one pair of electrodes and configures a resonance circuit together with a capacitive component of the piezoelectric member; a switch that is connected to the inductor in series; and a switch control unit that connects the switch when a transformation direction of the piezoelectric member is switched, and cuts off the switch when a time corresponding to a half period of a resonance period of the resonance circuit elapses.

Abstract: A liquid jet apparatus according to the present invention includes a drive circuit adapted to apply a drive signal to an actuator of a liquid jet head, and a power supply voltage control circuit adapted to control a power supply voltage to the drive signal to be a waveform voltage set previously based on a reference signal obtained from one of the drive signal and a signal in a generation stage of the drive signal.

Abstract: A liquid circulating device includes a pump chamber whose volume is changed by a volume changing unit; an inlet channel that is an inflow passage of the liquid to the pump chamber; a liquid resistance element; an outlet channel; a circulation channel of a length L through which the liquid circulates from the outlet channel to the inlet channel; and a pressure regulating mechanism that contains the liquid of a volume Vb during the non-operation of the volume changing unit and supplies the contained liquid as part of the circulating liquid during the operation of the volume changing unit. When the compliance of the circulation channel is defined as Cs, and the pressure of the liquid in the circulation channel at the position of a length x from the outlet channel during the operation of the volume changing unit is defined as P(x), the volume Vb satisfies a predetermined relationship.

Abstract: A head drive apparatus of an inkjet printer includes nozzles and corresponding actuators that eject liquid drops. A drive unit applies a drive signal to the actuators. The drive unit includes a drive waveform generator that generates a drive waveform signal as a reference of a signal to control drive of the actuators. A modulator pulse modulates a drive waveform signal generated by the drive waveform generator. A digital power amplifier amplifies power of a modulated signal subjected to the pulse modulation. A low pass filter smoothes an amplified digital signal subjected to the power amplification by the digital power amplifier and supplying the signal as a drive signal to the actuators. An inverse filter provided in a subsequent stage of the drive waveform generator corrects at least the frequency characteristics of the filter to predetermined frequency characteristics, independently of the number of the actuators to drive.

Abstract: A head drive of an inkjet printer includes nozzles and corresponding actuators that eject liquid ink drops. A drive unit applies a drive signal to the actuators. The drive unit includes a drive waveform generator that generates a drive waveform signal to control the drive of the actuators. A modulator pulse modulates the drive waveform. A digital power amplifier amplifies power of the modulated signal. A low pass filter smoothes the amplified digital signal and supplies the signal as a drive signal to the actuators. An inverse filter provided in a subsequent stage of the drive waveform generator corrects at least the frequency characteristics of the filter to predetermined frequency characteristics, independent of the number of the actuators to drive.

Abstract: A fluid ejection device that ejects fluid from an ejection port includes: a drive element that ejects fluid in accordance with a difference between voltages applied to a first terminal and a second terminal; a drive voltage waveform storing unit that stores a drive voltage waveform applied to the drive element; a plurality of power supplies each having a different voltage; and a drive voltage waveform applying unit that applies the drive voltage waveform to the drive element by switching among the plurality of power supplies connected to the first and second terminals of the drive element.

Abstract: A power generation unit includes: a deforming member adapted to deform while switching a deformation direction; a piezoelectric device provided to the deforming member, and having a pair of electrodes; a displacement sensor adapted to detect a deformation amount of the deforming member, and then output deformation amount information as information related to the deformation amount; an inductor electrically connected to the piezoelectric device; a switch disposed between the piezoelectric device and the inductor; and a switch control section adapted to control the switch so as to set the pair of electrodes to a shorted state for a predetermined period of time when the deformation amount exceeds a predetermined level.

Abstract: A power generation unit includes a deforming member adapted to repeatedly deform a piezoelectric element, a pair of electrodes provided to the piezoelectric element, an inductor disposed between the pair of electrodes, and constituting a resonant circuit together with a capacitive component of the piezoelectric element, a first switch connected in series to the inductor, a member adapted to detect a timing at which a deformation direction of the deforming member is switched, a full bridge rectifier adapted to rectify a current output from the pair of electrodes, a capacitor connected to the full bridge rectifier, and adapted to store a current supplied from the full bridge rectifier, a second switch connected between either one of the pair of electrodes and the capacitor, and a control circuit adapted to operate the first switch and the second switch.

Abstract: A power amplifier includes: a modulator pulse-modulating a drive waveform signal serving as a reference of a drive signal applied to an actuator and outputting a plurality of modulated signals; a digital power amplifier having a plurality of digital power amplifier stages each including a pair of push-pull switching elements, amplifying the power of the plurality of modulated signals, and outputting multi-value amplified digital signals; and a low pass filter smoothing the amplified digital signals and outputting the drive signal, wherein the modulator includes a control section switching one of a state where the same modulated signal is connected to two or more of the digital power amplifier stages and a state where different modulated signals are connected to different digital power amplifier stages to the other.

Abstract: A pump chamber is connected to an outlet-side buffer chamber via an outlet channel, and pumps a liquid from the outlet-side buffer chamber. A pressure vibration generated within the pump chamber when the volume of the pump chamber is decreased includes various kinds of information relating to the operating states of the liquid feed pump, such as mixing of bubbles, pumping pressure, dissolved gas amount, and liquid feed amount. Thus, it is possible to detect the pressure vibration, thereby simply and easily detecting the various kinds of information relating to the operating states of the liquid feed pump.

Abstract: A fluid feed pump is configured, such that a fluid is fed from an outlet channel of the fluid feed pump through an outlet buffer chamber to a fluid channel. The outlet buffer chamber is designed to have a higher compliance than a compliance of a pump chamber. The driving period of the fluid feed pump is set to a shorter period than a time constant defined by the compliance of the pump chamber and a flow resistance between an inlet of the outlet channel and an outlet of the fluid channel. This enables the fluid to be fed with high efficiency by taking advantage of the pressure oscillation occurring between the pump chamber and the outlet buffer chamber.

Abstract: A capacitive load driving circuit that drives an electrical load having a capacitive component, includes: a first power supply generating a first voltage; a second power supply generating a second voltage different from the first voltage; a plurality of charge storage elements charged by the first power supply; a first connection unit that connects the plurality of charge storage elements to the electrical load by switching connections among the charge storage elements; and a second connection unit that connects the second power supply to the electrical load.

Abstract: A fluid ejection device includes: a modulator adapted to pulse-modulate a drive waveform signal forming a basis of a drive signal of an actuator to obtain a modulated signal; a digital power amplifier circuit adapted to power-amplify the modulated signal to obtain a power-amplified modulated signal; a low pass filter adapted to smooth the power-amplified modulated signal to obtain the drive signal; and a power amplification stopping section operating when holding a voltage of the actuator constant.

Abstract: A liquid jet apparatus according to the present invention includes a drive waveform generator adapted to generate a drive waveform signal, a modulator adapted to execute pulse modulation on the drive waveform signal, a digital power amplifier adapted to power-amplify the modulated signal, on which the pulse modulation is executed by the modulator, with a pair of switching elements push-pull coupled with each other, a low pass filter adapted to smooth the amplified digital signal obtained by the power-amplification of the digital power amplifier, and a modulation period modification circuit adapted to modify a modulation period of the pulse modulation of the modulator based on data of the drive waveform signal.

Abstract: A liquid ejecting device includes a driving waveform signal generating circuit that generates a driving waveform signal, a modulation circuit that performs pulse modulation on the driving waveform signal to generate a modulation signal, a digital power amplifier that amplifies power of the modulation signal to generate a power amplification modulation signal in the form of a pulse wave, a filter that smoothes the power amplification modulation signal in the pulse wave to generate the driving signal, a connection cable that connects the filter to the capacitive load and is provided such that at least one of the filter and the capacitive load is detachable, a connection line information acquiring unit that acquires connection line information associated with the connection cable, and a frequency changing unit that changes a frequency when the modulation circuit performs the pulse modulation on the driving waveform signal, on the basis of the connection line.