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 pulse width modulation circuit includes: a reference signal generator which generates a plurality of mutually differing reference signals; a comparator which compares the reference signals and an input signal with respect to magnitude, and outputs results of the comparison as a plurality of comparison signals with mutually differing phases; and a synthesizer which, using a logical operation, outputs the plurality of comparison signals output from the comparator as a pulse width modulated signal configured of one or more binary signals.

Abstract: A capacitive load driving circuit includes: a voltage waveform output unit that outputs a voltage waveform used for driving a plurality of capacitive loads; and a voltage waveform applying unit that connects each of the plurality of capacitive loads to output of the voltage waveform output unit to thereby apply the voltage waveform to each of the plurality of capacitive loads, wherein the voltage waveform applying unit releases the connection between the capacitive load and the output of the voltage waveform output unit when voltage of the voltage waveform falls outside a voltage range determined for each of the plurality of capacitive loads, and connects the capacitive load to the output of the voltage waveform output unit when the voltage of the voltage waveform falls within the voltage range, to thereby apply a different voltage waveform to each of the plurality of capacitive loads.

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 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 apparatus which, by applying a drive voltage waveform to a piezoelectric element which drives an ejection nozzle, ejects a liquid from the ejection nozzle. The apparatus includes a reference voltage generating unit which generates a plurality of reference voltages, a drive voltage waveform data storage unit classifies the drive voltage waveform as either a voltage increasing section, decreasing section, or holding section, and stores drive voltage waveform data including a required time of a waveform section configuring the drive voltage waveform, and a voltage, selected from the plurality of reference voltages for the waveform section. The apparatus also includes a drive voltage waveform application unit which, in accordance with information relating to an adjustment of the ejection amount of the liquid ejected from the ejection nozzle, changes the required time included in the drive voltage waveform data, and applies the drive voltage waveform to the piezoelectric element.

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 power amplifier includes: a modulator pulse-modulating a drive waveform signal serving as a reference of a drive signal applied to actuators and outputting a modulated signal; a digital power amplifier amplifying the power of the modulated signal and outputting an amplified digital signal; a low pass filter smoothing the amplified digital signal and outputting the drive signal; and an inverse filter circuit being disposed at a front stage of the modulator and capable of obtaining a desired waveform precision of the drive signal even when a frequency characteristic of a filter including the low pass filter and an electrostatic capacitor of the actuators varies depending on the number of driven actuators, wherein the inverse filter circuits include a plurality of inverse filters connected in series.

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 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 fluid ejection device including, a drive element capable of storing a charge depending on a voltage applied to the drive element, a first capacitor, a second capacitor, and a power recovery module that recovers power from the drive element by connecting the first capacitor and the second capacitor to the drive element in series, wherein the power recovery module switches the first capacitor out of the in-series connection to further recover power from the drive element.

Abstract: A driving device of a capacitive load includes a modulator that executes pulse modulation on a drive waveform signal. An inductor performs low-pass filtering on the modulated drive waveform signal and outputs the low-pass filtered signal as a drive signal towards a load capacitor as the capacitive load. A load selection control circuit selects a load capacitor and a dummy load capacitor to be connected to the inductor so that a sum of the capacitances of the selected load capacitor and dummy load capacitor is kept within a predetermined range. A feedback circuit executes a filtering process on the drive signal so that a frequency characteristic of a passing band of the drive signal becomes substantially flat. The resulting signal is provided to the modulator as a feedback signal. The modulator executes the pulse modulation on a difference value between the drive waveform signal and the feedback signal.

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 power amplifier includes: a modulator pulse-modulating a drive waveform signal serving as a reference of a drive signal applied to actuators and outputting a modulated signal; a digital power amplifier amplifying the power of the modulated signal and outputting an amplified digital signal; a low pass filter smoothing the amplified digital signal and outputting the drive signal; and an inverse filter circuit being disposed at a front stage of the modulator and capable of obtaining a desired waveform precision of the drive signal even when a frequency characteristic of a filter including the low pass filter and an electrostatic capacitor of the actuators varies depending on the number of driven actuators, wherein the inverse filter circuits include a plurality of inverse filters connected in series.

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: 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 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 pulse width modulation circuit includes: a reference signal generator which generates a plurality of mutually differing reference signals; a comparator which compares the reference signals and an input signal with respect to magnitude, and outputs results of the comparison as a plurality of comparison signals with mutually differing phases; and a synthesizer which, using a logical operation, outputs the plurality of comparison signals output from the comparator as a pulse width modulated signal configured of one or more binary signals.

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.