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 liquid ejection device includes: a drive waveform generator generating a drive waveform signal; a modulator performing pulse modulation on a signal from the drive waveform generator to provide a modulated signal; a digital power amplifier performing power amplification on the modulated signal to provide an amplified digital signal; a Lowpass Filter smoothing the amplified digital signal to provide a drive signal of an actuator; a compensator advancing the phase of the drive signal to provide a negative feedback signal; and a subtractor providing a differential signal between the drive waveform signal and the negative feedback signal as an input signal to the modulator.

Abstract: In a ring network including an old master node 100, a new master node 110 is used as a replacement for the old master node 110. During replacement operation, when detecting that two ring ports of the new master node 110 are set in link-up state, the new master node 110 gives a transit node 200 an instruction to forward a health check frame H102 sent from a ring port 102 of the old master node 100 by a forwarding route going through the new master node 110. The new master node 110 can monitor the status of the ring network by receiving the health check frame H102. This configuration enables continuous monitoring for a failure occurring in the ring network during replacement of the master node.

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: An electric load driving circuit for driving an electric load having a capacity component includes a plurality of power sources generating different voltages, capacitors provided parallel to the plurality of power sources, a switch control unit that switches connections between the capacitors and the electric load and thereby switching a voltage applied to the electric load, discharge paths that enable discharging electric charge stored in the capacitor, and a discharge control unit that controls a quantity of electric charge discharged from the discharge paths.

Abstract: A modulated signal is generated by performing pulse modulation of a drive waveform signal that is a reference for a drive signal to be applied to a capacitive load, and the drive signal is generated by performing power amplification of the acquired modulated signal and then smoothing the power-amplified modulated signal. Then, negative feedback of the drive signal applied to the capacitive load is applied to the drive waveform signal that is the reference for the drive signal. At this time, a predetermined analog compensation process for smoothing gain characteristics in a frequency band included in the drive signal is performed for the drive signal, then the acquired signal is converted into a digital signal, and negative feedback of the digital signal is applied to the drive waveform signal.

Abstract: A power generator includes a deforming unit that deforms a piezoelectric member, a pair of electrodes provided on the piezoelectric member, an inductor provided between the pair of electrodes and forming a resonator circuit with a capacity component of the piezoelectric member, a first switch connected in series with respect to the inductor, a unit that detects times when a deformation direction of the deforming unit is switched, a full-wave rectifier circuit that rectifies a current output from the pair of electrodes, an electrical storage device connected to the full-wave rectifier circuit and charging a current supplied from the full-wave rectifier circuit, a second switch connected between one of the pair of electrodes and the electrical storage device, and a control circuit that operates the first switch and the second switch.

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 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: In a ring network including an old master node 100, a new master node 110 is used as a replacement for the old master node 110. During replacement operation, when detecting that two ring ports of the new master node 110 are set in link-up state, the new master node 110 gives a transit node 200 an instruction to forward a health check frame H102 sent from a ring port 102 of the old master node 100 by a forwarding route going through the new master node 110. The new master node 110 can monitor the status of the ring network by receiving the health check frame H102. This configuration enables continuous monitoring for a failure occurring in the ring network during replacement of the master node.

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 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.