A printing apparatus includes first and second actuators for exerting force to liquid, the number of the second actuators being smaller than the number of the first actuators; a switching circuit; first, second and third power circuits for applying voltages to the first and second actuators; and a controller for controlling driving of the first and second actuators. The controller is configured to control the switching circuit to electrically connect the first power circuit and some of the first actuators, electrically connect the second power circuit to the other of the first actuators and electrically connect the third power circuit to the second actuators, based on the number of the first actuators and the number of the second actuators.

Systems and methods of mitigating the effects of crosstalk in an inkjet head. An inkjet head has ink channels that jet droplets of a liquid material using piezoelectric actuators. Drive waveforms provided to the piezoelectric actuators include jetting pulses that cause activation of the piezoelectric actuators to jet the droplets from the ink channels. When crosstalk exists between the ink channels of the inkjet head due to the piezoelectric actuators, the amplitude of the jetting pulses are modified to mitigate the crosstalk between the ink channels.

A drive circuit that drives a piezoelectric device including a drive signal selection control circuit which controls supply of the drive signal to the piezoelectric element, the drive circuit including a drive signal output circuit that outputs the drive signal, a power supply voltage signal output circuit that outputs a power supply voltage signal, and a power supply voltage control circuit that controls supply of the power supply voltage signal to the drive signal selection control circuit, in which the drive signal output circuit includes a modulation circuit, an amplification circuit, a demodulation circuit, a feedback circuit, and a discharge circuit, a first wiring electrically couples the drive signal selection control circuit and the power supply voltage control circuit to each other, and the discharge circuit is electrically coupled to a second wiring through which the drive signal output from the demodulation circuit propagates, through the feedback circuit.

A capacitive load driving circuit for repeating between charging and discharging for a capacitive load includes a charge supply source, a first signal path through which a first voltage is applied by the charge supply source, a second signal path through which a second voltage higher than the first voltage is applied by the charge supply source, and a connection path selector configured to electrically connect the capacitive load and the charge supply source via at least one of the first signal path and the second signal path, in accordance with a control signal. The charge supply source is arranged and configured to supply voltage to the connection path selection section.

A liquid discharge apparatus includes a liquid discharge head and a head drive controller. The liquid discharge head includes an actuator including an electromechanical transducer element. The head drive controller controls the liquid discharge head. The head drive controller includes a drive waveform generator and a voltage updater. The drive waveform generator generates a drive waveform to be applied to the electromechanical transducer element. The voltage updater updates a voltage value of the drive waveform to a larger value with an elapse of time. The voltage updater sets a time interval of update of the voltage value to be longer as a number of times of the update is greater.

A printhead circuit or driving at least two actuating elements has a trim generating circuit for generating a trim signal using a comparator coupled to receive and compare feedback indicative of a present level of a drive voltage, with a configurable reference voltage value. The trim being based on a drive voltage feedback can give a more direct indication of actuating element output than given by timing references. Hence the trim can be more accurate, can be simpler, without accurate digital timing references, and thus costs can be reduced. It can be combined with a cold switch arrangement.

A head driving device drives a liquid ejection head. The liquid ejection head includes a plurality of nozzles and a plurality of pressure generating devices provided respectively corresponding to the nozzles. The head driving device includes a driving-waveform correcting unit configured to correct driving waveform data that defines ejection characteristics of liquid to be ejected from the nozzle based on interference patterns expressing variations in the ejection characteristics caused by an interference occurring in the nozzle.

A liquid discharge apparatus uses a drive signal including a micro-vibration waveform which causes the piezoelectric element to micro-vibrate such that an ink is not discharged from the nozzle in a case of being applied to the piezoelectric element as the drive signal and a drive waveform which deforms piezoelectric element such that the ink is discharged from the nozzle in a case of being applied to the piezoelectric element as the drive signal. The presentation unit selectably presents the indirect information from which the ink discharge status can be estimated such as the types of ink and the usage status of the ink or the like. The control unit changes the strength of the micro-vibration caused by the micro-vibration waveform based on the indirect information selected on the presentation unit.

A digital printing system (10) includes a print head (622) and a processor (20). The print head is configured to jet droplets of ink. The processor is further configured to translate a required shade of a color, to be printed at a given location on a substrate by tire print head, into a sequence of pulses (625, 630), the sequence including: (a) up to a predefined maximum number of driving pulses (625) that cause the print head to jet respective droplets, and (b) a tickling pulse (630), which has a smaller amplitude than the driving pulses and which causes the print head to jet a droplet smaller than the droplets jetted in response to the driving pulses. The processor is additionally configured to apply the sequence of pulses to the print head.

In one example in accordance with the present disclosure, a fluid ejection system is described. The fluid ejection system includes a frame to retain a number of fluid ejection devices. Each fluid ejection device includes a reservoir disposed on a first side of the frame and a fluid ejection die disposed on an opposite side of the frame. Each fluid ejection die includes 1) a fluid feed slot formed in a substrate to receive fluid from the reservoir, 2) an array of nozzles formed in the substrate to eject fluid, and 3) an ejection adjustment system to selectively adjust an amount of fluid ejected from the fluid ejection devices.