A driving signal generation circuit generates a main driving signal including, in each of driving periods, at least a first sub driving signal including a first driving pulse and a second driving pulse, and a second sub driving signal including a third driving pulse and provided before the first sub driving signal. A driving signal supply circuit includes a first dot generator supplying the first sub driving signal but not supplying the second sub driving signal to an actuator coupled with a vibration plate defining a portion of a pressure chamber, and a second dot generator supplying the first sub driving signal and the second sub driving signal to the actuator.

A method of forming a feature by dispensing a metallic nanoparticle composition from an ink-jet print head is disclosed. A jetting waveform is applied to piezoelectric actuator to dispense droplets of the metallic nanoparticle composition through nozzle opening. The droplets range in volume between 0.5 picoliter and 2.0 picoliter. The jetting waveform includes an intermediate contraction waveform portion, a final contraction waveform portion after the intermediate contraction waveform portion, and an expansion waveform portion after the final contraction waveform portion. During the intermediate contraction waveform portion, an applied voltage increases from an initial low voltage to an intermediate voltage and then is held at the intermediate voltage. During the final contraction waveform portion, the applied voltage increases from the intermediate voltage to maximum voltage and then is held at the maximum voltage. During the expansion waveform portion, the applied voltage decreases from the maximum voltage to a final low voltage.

A liquid injection device includes a liquid injection head and a controller including a driving signal generator generating a driving signal including, in one liquid drop injection period, a first driving pulse and a second driving pulse, and a driving signal supplier. The first driving pulse maintains the pressure chamber in an expanded state for a time period of about ()Tc; and the second driving pulse starts at a timing that is about nTc after the start of the first driving pulse, n being an integer satisfying n2, to maintain the pressure chamber in the expanded state for the time period of about ()Tc, and to inject the second liquid drop at a speed higher than, or equal to, a speed at which the first liquid drop is injected.

There are provided a liquid jet head and a liquid jet recording device each capable of appropriately cutting off the liquid column formed immediately after being jetted from the jet hole to prevent the satellite droplet from generating, and further achieving easier maintenance of the jet hole part. The liquid jet head includes a drive actuator, a jet hole plate, and a flow channel operating actuator. The drive actuator applies a pressure variation to a liquid filled therein. The jet hole plate is disposed on a downstream side of the drive actuator and adapted to jet the liquid having flown out from the drive actuator from the jet hole to the outside of the drive actuator. The flow channel operating actuator is disposed between the drive actuator and the jet hole plate, provided with a communication section adapted to communicate the drive actuator and the jet hole with each other, and has a configuration capable of performing a displacing operation on at least a part of the peripheral edge part of the communication section.

A head voltage correcting method for inkjet printing apparatus which perform printing with a head having a plurality of head modules includes the following steps: a testing chart printing step for printing testing charts which includes a lowest density head module check pattern, satellite check patterns, band-by-band density variable patterns, and in-band density variable patterns; a lowest density head module determining step for determining a lowest density head module; a satellite-free drive voltage determining step; and a new reference voltage determining step for determining a drive voltage of the band-by-band density variable patterns of the adjacent head module to be a new reference voltage for the adjacent head module.

Methods of ejecting droplets containing a non-Newtonian fluid by an acoustic droplet ejector can include applying a tone burst of focused acoustic energy to a fluid reservoir containing a non-Newtonian fluid at sufficient amplitude to effect droplet ejection according to a tone burst pattern. The tone burst pattern may include three discrete tone burst segments, the first tone burst segment having greater duration than the second and third segments, and third segment having greater duration than the second segment. The exact durations and amplitudes of the tone burst segments can be tuned to influence the ejection properties.

A printing apparatus comprising a carriage on which a printhead is mounted, wherein the printhead is configured to discharge droplets onto a printing medium from a nozzle of the printhead while moving the carriage relative to the printing medium is provided. The printing apparatus performs: detecting droplets discharged from the nozzle; controlling discharge of droplets from the nozzle; and determining a discharging state of the nozzle based on a result of detection, wherein droplets are discharged from the nozzle while the carriage is moving, and wherein the control unit determines the discharging state of the nozzle based on comparison of a threshold stored in a storage unit and information related to a discharging state corresponding to that of some of the droplets discharged from the nozzle while the carriage is moving, the information being derived from a result of detection of the droplets.

A system includes a print head including multiple nozzles formed in a bottom surface of the print head. The nozzles are configured to eject a liquid onto a substrate. The system includes a gas flow module configured to provide a flow of gas through a gap between the bottom surface of the print head and the substrate. The gas flow module can include one or more gas nozzles configured to inject gas into the gap. The gas flow module can be configured to apply a suction to the gap.

Disclosed is a liquid discharge method of discharging liquid with a liquid discharge head having a heating surface that contacts and heats the liquid and a discharge port that faces the heating surface and discharges the liquid. The method includes heating the liquid through the heating surface to generate a bubble such that the bubble communicates with an atmosphere, thereby discharging the liquid. The liquid that is being discharged from the discharge port includes a trailing portion. The trailing portion moves toward the heating surface in response to a reduction in volume of the bubble and contacts the heating surface. The method further includes heating the trailing portion through the heating surface while the trailing portion is in contact with the heating surface, thereby generating a bubble.

A head voltage correcting method for inkjet printing apparatus which perform printing by dispensing ink droplets from a head to a printing medium. The method includes the following steps: a step of printing testing charts; a step of acquiring images of the testing charts; a step of determining presence or absence of satellite droplets for each drive voltage; a step of obtaining distances between the main droplets and the satellite droplets for each drive voltage; a step of obtaining a distance reference drive voltage from a relationship of the distances for each drive voltage and a distance threshold; a step of obtaining ink droplet sizes for each drive voltage; a step of obtaining a size reference drive voltage; and a step of comparing the distance reference drive voltage and the size reference drive voltage, and making correction by adopting a larger one as the reference voltage.