A head unit includes a plurality of ejection portions that include a first ejection portion and a second ejection portion, a determination portion that determines a liquid ejection state of the first ejection portion and determines a liquid ejection state of the second ejection portion, and a storage portion that includes a first storage region storing first determination information indicating a determination result for the first ejection portion from the determination portion, and a second storage region storing second determination information indicating a determination result for the second ejection portion from the determination portion.

A head unit control device that controls a head unit including a plurality of ejection portions that includes a first ejection portion and a second ejection portion and a determination portion that determines a liquid ejection state of the first and second ejection portion, and includes a reception portion that receives, as one data set, determination result information including first determination information indicating a determination result of the liquid ejection state of the first ejection portion from the determination portion and second determination information indicating a determination result of the liquid ejection state of the second ejection portion from the determination portion, and ejection portion information including information indicating the number of the plurality of ejection portions included in the head unit, from the head unit, and an ejection control portion that controls the plurality of ejection portions based on the one data set received by the reception portion.

A print head includes: an integrated circuit apparatus that switches whether or not to supply drive signals to a plurality of piezoelectric elements, and includes a first circuit block that switches whether or not to supply the drive signal, a second circuit block that switches whether or not to supply the drive signal, a third circuit block that switches whether or not to supply the drive signal, a fourth circuit block, and a first buffer area, a second buffer area, and a third buffer area in which no circuit element is located, in which the first buffer area is located between the first circuit block and the fourth circuit block, the second buffer area is located between the second circuit block and the fourth circuit block, and the third buffer area is located between the third circuit block and the fourth circuit block.

Provided is a liquid discharging apparatus including a drive signal output circuit outputting a drive signal that displaces between a first potential and a second potential, and a discharging portion including a piezoelectric element that is driven based on the drive signal and discharging liquid, in which the drive signal output circuit includes a modulation circuit that outputs a modulation signal obtained by modulating a base drive signal that is a base of the drive signal, an amplification circuit that outputs an amplified modulation signal obtained by amplifying the modulation signal, and a demodulation circuit that includes a capacitor and outputs the drive signal obtained by demodulating the amplified modulation signal, the first potential is 25 V or higher, and the capacitor is a surface mounting component including a laminated portion in which a resin thin film layer and a metal thin film layer are laminated.

A grayscale inkjet printing method including the steps of: a) supplying a pigmented inkjet ink to a grayscale print head having nozzles with an outer nozzle surface area smaller than 500 μm.sup.2 and having an acoustic resonance period ARP of not more than 5.5 μs; and b) applying a voltage wave form for ejecting pigmented inkjet ink from a nozzle of the grayscale print head within one jetting cycle; wherein the pigmented inkjet ink has a viscosity of at least 3.8 mPa.Math.s at jetting temperature and a shear rate of 1,000 s.sup.−1; wherein the voltage wave form for ejecting the largest ink droplet includes, in chronological order, a first ejecting pulse having an amplitude A1 and a second ejecting pulse having an amplitude A3 with the amplitude A1 complying with the relationship: 0.50×A3<A1<1.40×A3; and wherein a time period between the end time of the first ejecting pulse and the end time of the second ejecting pulse defines an idle time period including no other ejecting pulse, the time period having a duration between 1.5 to 2.5 times the acoustic resonance period ARP; and wherein any non-ejecting pulse having an amplitude A2 present during the idle time period complies with the relationship: A2≤0.15×A3. An inkjet printing system is also disclosed.

A liquid jetting device is arranged to eject a droplet of a liquid. The device includes a nozzle, a liquid duct connected to the nozzle, an electro-mechanical transducer arranged to create an acoustic pressure wave in the liquid in the duct, and an electronic control system arranged to apply to the transducer a voltage signal having a waveform configured for ejecting a droplet from the nozzle. The waveform is further configured to quench a residual acoustic pressure wave in the liquid duct and includes a jet pulse, a subsequent first quench pulse having a polarity opposite to that of the jet pulse, and a subsequent second quench pulse having the same polarity as the jet pulse.

A digital printing system includes a print head and a processor. The print head is configured to jet droplets of ink. The a processor is further configured to translate a required shade of a color, to be printed at a given location on a substrate by the print head, into a sequence of pulses, the sequence including: (a) up to a predefined maximum number of driving pulses that cause the print head to jet respective droplets, and (b) a tickling pulse, 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.

A liquid ejection head includes a nozzle for ejecting a droplet of a liquid, a pressure chamber connected to the nozzle, an actuator for changing a volume of the chamber according to a voltage signal, and a drive circuit generating the signal for ejecting n droplets, where n is an integer of 3 or more. The signal includes (n−1) ejection pulses, comprising a first pulse lowering the voltage signal to a first value to expand the chamber and then to a second value to contract the chamber, and a second pulse lowering the voltage signal to the first value and then to a third value higher than the second value. The pulses are input at intervals of 0.8λ to 1.2λ, where λ is a primary natural vibration period of the chamber filled with the liquid.

A liquid discharge head includes: a channel substrate having a nozzle and a channel communicating with the nozzle; a driving element arranged on the channel substrate; and a driving signal generating circuit which generates a driving signal to drive the driving element. The driving signal includes a non-discharge driving signal by which the driving element is driven so that liquid in the channel is not discharged from the nozzle. The non-discharge driving signal includes at least one first slight-vibration waveform and at least one second slight-vibration waveform. The first slight-vibration waveform is a waveform by which the driving element is displaced by a first displacement amount. The second slight-vibration waveform is a waveform by which the driving element is displaced by a second displacement amount that is larger than the first displacement amount. The at least one second slight-vibration waveform follows after the at least one first slight-vibration waveform.

A print head assembled to a liquid ejecting apparatus ejecting a liquid with respect to a medium includes an ejecting portion ejecting the liquid in response to a drive signal and an electrically erasable non-volatile memory, and the non-volatile memory stores history information changing in accordance with an operation state of the print head.