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: An excision device configured to excise living tissue by ejecting liquid includes: a supplying unit configured to supply liquid to be ejected; a chamber configured to be filled with the supplied liquid; an ejection nozzle connected to the chamber; a drive member configured to be deformed in the direction to reduce the volume of the chamber when a drive voltage is applied more than a case where the drive voltage is not applied; a liquid ejecting unit configured to eject the liquid in the chamber in a pulsed manner from the ejection nozzle by applying the drive voltage to the drive member in a state in which the chamber is filled with the supplied liquid; and an air-bubble detecting unit configured to detect air bubbles in the chamber by detecting an electric current flowing in the drive member when the drive voltage is applied to the drive member.

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 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.

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.

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, a displacement detection section adapted to detect that the deforming member is displaced beyond a predetermined level, an inductor electrically connected to the piezoelectric device, a switch disposed between the piezoelectric device and the inductor, and a control section adapted to set the piezoelectric device and the inductor to an electrically conductive state via the switch if the displacement detection section detects that the deforming member is displaced beyond the predetermined level.

Abstract: A capacitive load driving circuit includes: a drive waveform signal generator that generates a drive waveform signal; a subtractor that outputs a differential signal between the drive waveform signal and a feedback signal; a modulator that pulse-modulates the differential signal and outputs a modulated signal; a digital power amplifier that amplifies the power of the modulated signal and outputs a power-amplified modulated signal; a smoothing filter that smoothes the power-amplified modulated signal, and outputs a drive signal of the capacitive load; a compensator that causes a phase to precede the drive signal; and an attenuator that attenuates signal amplitude in a band at least including a modulation frequency of the modulated signal. A signal output from a connecting point between the inductor and the wire is made to pass through the compensator and the attenuator and is then used as a feedback signal to the subtractor.

Abstract: A fluid feeding pump which varies a volume of a pump chamber and thus feeds a fluid out of the pump chamber, includes: a piezoelectric element which accumulates electric charges inside when a voltage is applied, and which deforms according to an amount of accumulated electric charges and thus increases or decreases the volume of the pump chamber; a drive unit which applies a drive signal with a waveform increasing to a predetermined maximum voltage and then decreasing, and thus drives the piezoelectric element; and an air bubble determining unit which detects a current flowing through the piezoelectric element within a predetermined period after the drive signal is applied to the piezoelectric element, and thus determines whether there are air bubbles in the pump chamber or not.

Abstract: Operation of a digital power amplifier for power amplification of a modulated signal is stopped in a period in which a voltage value of a drive signal applied to a capacitive load is constant, to thereby suppress power loss. The power amplification is stopped either when half a period of time when the modulated signal in a first voltage state maintains the first voltage state elapses or when half a period of time when the modulated signal in a second voltage state which is lower in voltage than the first voltage state maintains the second voltage state elapses. Accordingly, when electric current does not flow in a inductor of a low pass filter, it is possible to stop the power amplification. Thus, it is possible to prevent generation of voltage fluctuation in the drive signal due to an electromotive force caused by a self-induction phenomenon of the inductor.

Abstract: A liquid ejection device, includes: a drive waveform signal output circuit which outputs a drive waveform signal to serve as a reference for the drive signal; a modulator which pulse-modulates the drive waveform signal and thus generates a first modulated signal and a second modulated signal having a different phase from the first modulated signal within a range from greater than 90 degrees to smaller than 270 degrees; a first digital power amplifier; a second digital power amplifier a first low pass filter which performs low pass filtering of the first amplified digital signal and thus generates a first demodulated signal; and a second low pass filter which performs low pass filtering of the second amplified digital signal and thus generates a second demodulated signal; wherein the first demodulated signal and the second demodulated signal are combined and applied as the drive signal to the capacitive load.

Abstract: A fluid ejection device includes: a fluid chamber; a volume varying unit configured to vary the volume of the fluid chamber; a fluid supplying unit configured to supply fluid to the fluid chamber at a predetermined pressure; and an ejection command switching unit configured to switch a fluid ejection between a pulsed flow ejection which ejects the fluid in a pulsed manner by activating the volume varying unit and varying the volume of the fluid chamber and a continuous flow ejection which ejects the fluid with a fluid supply pressure from the fluid supplying unit higher than that in the case of the pulsed flow ejection in a state in which the volume varying unit is stopped.

Abstract: A power generation unit includes a deforming member (a beam) adapted to deform while switching a deformation direction, a first piezoelectric device provided to the deforming member (the beam), a second piezoelectric device provided to the deforming member (the beam), an inductor electrically connected to the first piezoelectric device, a switch disposed between the first piezoelectric device and the inductor, and a control section adapted to detect a voltage generated in the second piezoelectric device, and if the voltage detected has a level one of equal to and higher than a predetermined level, electrically connect the first piezoelectric device and the inductor to each other using the switch.

Abstract: A power generation unit includes a beam (a deforming member) having a piezoelectric element and deforming while switching a deformation direction, an inductor electrically connected to the piezoelectric element, a switch disposed between the piezoelectric element and the inductor, a memory (a storage section) adapted to store switching period information (information of a characteristic vibration period of the beam), and a control circuit (a control section) adapted to control one of a timing at which the switch is set to a conductive state and a timing at which the switch is set to a nonconductive state in accordance with the switching period information stored in the memory.

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 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 apparatus includes: a deformation member that is provided with a first piezoelectric device and deformed while switching a deformation direction; an amount of deformation detection unit that detects an amount of deformation of the deformation member; a pair of electrodes provided on the first piezoelectric device; a switch provided between the pair of electrodes; and a switch control unit that controls the switch to cause short-circuit between the pair of electrodes for a predetermined period when the amount of deformation is equal to or more than a predetermined amount.

Abstract: A fluid ejection device includes: a fluid chamber; a volume varying unit configured to vary the volume of the fluid chamber; a fluid supplying unit configured to supply fluid to the fluid chamber at a predetermined pressure; and an ejection command switching unit configured to switch a fluid ejection between a pulsed flow ejection which ejects the fluid in a pulsed manner by activating the volume varying unit and varying the volume of the fluid chamber and a continuous flow ejection which ejects the fluid with a fluid supply pressure from the fluid supplying unit higher than that in the case of the pulsed flow ejection in a state in which the volume varying unit is stopped.

Abstract: A power generation unit includes a deforming member (a beam) adapted to deform while switching a deformation direction, a first piezoelectric device provided to the deforming member (the beam), a second piezoelectric device provided to the deforming member (the beam), an inductor electrically connected to the first piezoelectric device, a switch disposed between the first piezoelectric device and the inductor, and a control section adapted to detect a voltage generated in the second piezoelectric device, and if the voltage detected has a level one of equal to and higher than a predetermined level, electrically connect the first piezoelectric device and the inductor to each other using the switch.

Abstract: A medical instrument for ejecting liquid includes a liquid chamber that contains the liquid, a driving unit that pressurizes the liquid contained in the liquid chamber, and a vibration detector that detects vibration when the driving unit is driven.

Abstract: A power generation unit includes a first piezoelectric device having a pair of electrodes, a second piezoelectric device stacked on the first piezoelectric device, a switch electrically connected between the pair of electrodes, a current detection section adapted to detect a current generated in the second piezoelectric device, and a control section adapted to control the switch, and the control section electrically connects the switch for a predetermined period in at least either one of a case in which the current detected by the current detection section reaches a level one of equal to and higher than a first reference value or a case in which the current reaches a level one of equal to and lower than a second reference value.