Abstract: A drive waveform signal as a reference of a drive signal to be applied to a piezoelectric element is power-amplified, and the drive signal after passing through a coil is applied to the piezoelectric element. A resonant circuit is formed of the coil and the piezoelectric element, and a resonant peak is suppressed by performing a phase advance compensation of the drive signal and by performing a negative feedback. At this time, the degree of suppression of the peak is adjusted so that a slight reverse voltage is generated. Since this can eliminate residual distortion of the piezoelectric element by the reverse voltage, even when driving is performed at a high repetition frequency, the original amount of deformation can be ensured. Besides, the circuit does not become complicated.

Abstract: A liquid jetting device includes a plurality of nozzles. A driving signal generated by a driving signal generating section is applied to a charge-discharge actuator in correspondence with each nozzle to jet liquid from the nozzle. A charging source potential preliminary adjusted wave-form signal is pulse modulated and electrically amplified using a charging source potential transistor pair connected in a push-pull configuration, and output by a ripple filter to a collector of a charge-use transistor of the driving signal generating section to make a preliminary adjustment to the charging source potential for the driving signal generating section.

Abstract: A fluid ejection device configured to eject fluid from an ejection port includes a driving element that pressurizes the fluid and causes it to be ejected from the ejection port by being driven according to a voltage applied thereto. A driving voltage waveform selecting unit selects a driving voltage waveform to be applied to the driving element from among a plurality of types of the stored driving voltage waveforms. Power sources set the voltage to be outputted. A power source voltage determining unit determines voltages to be set to the power sources on the basis of the selected driving voltage waveform. A driving voltage waveform applying unit applies the selected driving voltage waveform to the driving element by setting the determined voltages to the power sources and connecting the power sources to the driving element while switching the same.

Abstract: A liquid ejecting apparatus includes: a Modulator that performs pulse modulation for a drive waveform signal that becomes a reference for a drive signal of an actuator so as to acquire a modulated signal; a digital power amplifier that amplifies the power of the modulated signal so as to acquire a amplified digital signal; a low pass filter that smoothes the amplified digital signal so as to acquire the drive signal; a variable power source circuit that can change a power source voltage of the digital power amplifier; and a power source voltage control unit that controls changes in the power source voltage in units of a driving pulse that configures the drive signal of the actuator and can independently drive the actuator.

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: A liquid jet apparatus according to the invention is a liquid jet apparatus adapted to emit a jet of a liquid by driving an actuator of a liquid jet head with a drive signal including a digital power amplifier and a low pass filter provided to the liquid jet head so as to correspond to the actuator, and adapted to power-amplify and smooth a modified signal from a control circuit to form the drive signal, wherein the low pass filter is coupled directly with the actuator, and the digital power amplifier is provided with a pair of switching elements and a gate drive circuit, and ON-OFF controls the gate drive circuit based on print data, thereby performing one of output and halt of the drive 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 load driving circuit includes first storage elements charged by a power supply and a series storage element group constituting unit that switches the connection state between the first storage elements to constitute a series storage element group in which the first storage elements are connected in series. A second storage element charging unit charges a second storage element using the series storage element group. Switching is performed between first and second connection states to apply voltage to the load. In the first connection state, the charged second storage element and the series storage element group are connected to the load while the second storage element and the series storage element group are connected in series. In the second connection state, the series storage element group is connected to the load while the series connection between the second storage element and the series storage element group is broken.

Abstract: A capacitive load driving circuit that drives a capacitive load, includes: a power supply unit that generates different voltages; a plurality of charge storage elements that are charged with the different voltages generated by the power supply unit; and a load driving section that connects a charge storage element arbitrarily selected from the plurality of charge storage elements to the capacitive load to drive the capacitive load, and connects, when at least two of the charge storage elements are selected, the at least two charge storage elements to the capacitive load in a state where the at least two charge storage elements are connected in series.

Abstract: A reference voltage waveform reciprocating between a first voltage and a second voltage is supplied to a piezoelectric element via a switch. If a switch is set to a connected state (ON), the reference voltage waveform is applied to the piezoelectric element, and if the switch is set to a disconnected state (OFF), the voltage when the switch is set to OFF continues to be applied. Therefore, it becomes possible to apply a variety of drive signals only by switching the switch in accordance with increase and decrease of the reference voltage waveform, and there is no need to store a plurality of types of drive signals. Further, it is possible to start to apply the drive signal immediately when the voltage of the reference voltage waveform reaches the target voltage.

Abstract: A head drive apparatus of an ink jet printer having: a plurality of nozzles for jetting liquid drops that are provided for an ink jet head; a plurality of actuators provided in correspondence to the nozzles; and a drive unit that applies a drive signal to the actuators, wherein the drive unit comprising: a drive waveform generator that generates a drive waveform signal being standard of a signal to control drive of the actuators; a modulator that modulates a pulse of a drive waveform signal generated by the drive waveform generator; a digital power amplifier for amplifying power of a modulated signal subjected to the pulse modulation by the modulator; and a low pass filter for smoothing 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.

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 capacitive load driving device includes a drive waveform generator adapted to generate a drive waveform signal, a subtraction section adapted to output a differential signal between the drive waveform signal and two feedback signals, a modulator adapted to perform pulse modulation on the differential signal to obtain a modulated signal; a digital power amplifier adapted to power-amplify the modulated signal to obtain an amplified digital signal, a low pass filter including an inductor and a capacitor, and adapted to smooth the amplified digital signal to obtain a drive signal of a capacitive load, a first feedback circuit adapted to feedback the drive signal to the subtraction section as a first feedback signal, and a second feedback circuit adapted to set forward a phase of the drive signal and to feed back the drive signal to the subtraction section as a second feedback signal.

Abstract: A fluid ejection device includes, a modulator, a digital power amplifier, a low pass filter, and an inverse filter circuit, including, a delay device, a subtracter that subtracts an output signal of the delay device from a drive waveform signal, an amplifier adapted to amplify an output signal of the subtracter, an adder that adds an output signal of the amplifier and another input signal, a first switch adapted to perform switching so as to set either one of the drive waveform signal and an output signal of the adder to be an input signal of the delay device, a second switch adapted to perform switching so as to set either one of the drive waveform signal and the output signal of the delay device to be the another input signal of the adder, and a switch connection control section that controls the first switch and the second switch.

Abstract: A liquid jet apparatus includes a plurality of nozzles provided to a liquid jet head, an actuator provided corresponding to each of the nozzles, and drive unit that applies a drive signal to the actuator, wherein the drive unit includes drive waveform signal generation unit that generates a drive waveform signal providing a basis of a signal for controlling the operation of the actuator, modulator unit that pulse-modulates the drive waveform signal generated by the drive waveform signal generation unit, a digital power amplifier for power-amplifying the modulated signal, which is pulse-modulated by the modulator unit, a low-pass filter for smoothing the power-amplified and modulated signal power-amplified by the digital power amplifier and supplying the actuator with the power-amplified and modulated signal as the drive signal, and carrier frequency adjusting unit that adjusts a carrier frequency of the pulse modulation by the modulator unit in accordance with the number of the actuators to be driven.

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: A liquid jet apparatus includes a plurality of nozzles, an actuator provided for each nozzle and connected to the respective nozzle, and a drive unit that applies a drive signal to the actuator, wherein the drive unit includes: a drive waveform signal generation unit that generates a drive waveform signal for controlling the operation of the actuator, a modulator unit that pulse-modulates the drive waveform signal to produce a modulated signal, a digital power amplifier for power-amplifying the modulated signal to produce an amplified signal, a low-pass filter for smoothing the amplified signal and supplying the actuator with the drive signal, and a carrier frequency adjusting unit that adjusts a carrier frequency of the pulse modulation by the modulator unit in accordance with the number of actuators to be driven.

Abstract: A head drive device of an inkjet printer having a nozzles and corresponding actuators that jet liquid drops. A drive section that generates a drive signal to the actuators. The head drive device includes a drive waveform signal which is used as a reference of a signal to control drive of the actuators. A modulating section modulates a pulse of a drive waveform signal generated by the drive waveform generating system. A low pass filter smoothes a power-amplified modulated signal subjected to the power amplification by the digital power amplifier and supplies the signal as a drive signal to the actuators. A frequency characteristics adjusting section adjusts frequency characteristics of the low pass filter as a function of the number of the actuators.

Abstract: A liquid jet apparatus includes a plurality of nozzles provided to the liquid jet head, an actuator provided corresponding to each of the nozzles, drive unit that applies a drive signal to the actuator, drive waveform signal generation unit that generates a drive waveform signal providing a reference of a signal for controlling the actuator, modulator unit that pulse-modulates the drive waveform signal generated by the drive waveform signal generation unit, a digital power amplifier for power-amplifying the modulated signal, which is pulse-modulated by the modulator unit, and a low-pass filter provided individually corresponding to the actuator and for supplying the actuator with the power amplified modulated signal power-amplified by the digital power amplifier as a drive signal after smoothing.

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.