A jetting device includes an ejection unit arranged to eject a droplet of a liquid. The ejection unit includes a nozzle, a liquid duct connected to the nozzle, and an electro-mechanical transducer arranged to create an acoustic pressure wave in the liquid in the duct. The jetting device further includes a filter arranged to filter the liquid being supplied into the duct and a filter status detection system arranged to detect an obstruction status of the filter by measuring a property of the liquid in the duct. The filter status detection system includes a circuit configured for measuring the electric response of the transducer, for recording changes in the electric response that represent pressure fluctuations induced by the acoustic wave in the form of a time-dependent function, and for judging the obstruction status of the filter on the basis of that function.

There is provided a head module in which a first direction is a main scanning direction, including: a first nozzle row including a first nozzle; a second nozzle row including a second nozzle; and a third nozzle row including a third nozzle, in which a distance P1 between the first nozzle row and the second nozzle row in the first direction and a distance P2 between the first nozzle row and the third nozzle row in the first direction are expressed as P1:P2=E1:O1 where a value E1 is a positive even number and a value O1 is a positive odd number satisfying O1>E1.

A maintenance method for a liquid discharging apparatus including a liquid discharging head. The liquid discharging apparatus executes a printing process including a discharging process in which the liquid discharged from the liquid discharging head lands on the medium, and a maintenance process in which the liquid is discarded from the liquid discharging head. The maintenance method includes: counting a unit period number, which is the number of ended unit periods among a plurality of unit periods obtained by dividing a period required for the printing process in accordance with a first condition; executing the maintenance process when the unit period number reaches a defined number; acquiring viscosity information related to viscosity of the liquid inside the liquid discharging head; and decreasing the unit period number when the viscosity information satisfies a second condition.

A viscosity measurement device includes a measurement tool having a pump for feeding a printing liquid by pressure. The viscosity measurement device includes a passage part having a first passage part in which a flow path cross-sectional area for the printing liquid is set at a first area, and a second passage part in which a flow path cross-sectional area for the printing liquid is set at a second area smaller than the first area and which is arranged on an upstream side in a supply direction of the printing liquid with respect to the first passage part, the passage part being interposed in the supply path and arranged upward toward a downstream side in the supply direction of the printing liquid; and a sensor attached to the second passage part and measuring the fall time of the measurement tool in a prescribed vertical region in the second passage part.

A liquid discharge apparatus includes: a liquid discharge head configured to discharge a liquid from a nozzle, the liquid discharge head including: a liquid chamber communicating with the nozzle; a pressure generator configured to deform the liquid chamber to apply pressure to the liquid in the liquid chamber; and circuitry configured to apply a drive signal to the pressure generator to drive the pressure generator, the drive signal including at least one drive pulse. The drive pulse includes: an expansion element to expand the liquid chamber to a first volume; a holding element to hold the first volume of the liquid chamber expanded by the expansion element for a predetermined time; and a contraction element to contract the liquid chamber from the first volume held by the holding element to a second volume.

A printing apparatus includes a printing head that includes a plurality of nozzles, each of which ejects an ink pushed out from a pressure chamber by driving of an actuator, a display unit, a detector that generates a residual vibration in the pressure chamber by imparting, to the actuator, a predetermined drive signal that prevents the nozzle from ejecting the ink, and, based on the residual vibration, performs, for each of the plurality of nozzles, defective nozzle detection processing of detecting a defective nozzle having ejection failure, and a display control unit that causes the display unit to display defective nozzle information including a position, in the printing head, of the defective nozzle detected by the detector.

An inkjet printing apparatus includes a printing unit having ejection parts, each configured to eject ink by using a piezoelectric element to be displaced in response to a change in electric potential. The inkjet printing apparatus also includes a circulation unit, a determination unit, and a control unit. The circulation unit executes ink circulation in a circulation path inclusive of the printing unit. The determination unit ejects the ink from each ejection part, detects residual vibration generated at an ejection part due to ink ejection, and determines an ejection state of ink ejection at the ejection part based on the detected residual vibration. The inkjet printing apparatus determines a printing state of ink ejection in the printing unit based on the ejection state. The control unit causes the determination unit not to make the ejection state determination in parallel with causing the circulation unit to execute the ink circulation.

A liquid ejecting system includes a head unit that includes a pressure chamber, a drive element driven by an applied drive waveform, a vibration plate that vibrates by drive of the drive element, and a nozzle through which a liquid is ejected by a pressure applied in the pressure chamber by vibration of the vibration plate, and an input portion to which an input parameter for detecting an ejection failure of the liquid based on residual vibration of the vibration plate is input from a server through a network connection portion.

A liquid ejecting system includes a head unit that includes a nozzle for ejecting a liquid, a pressure chamber communicating with the nozzle, and a drive element for applying pressure fluctuation to a liquid in the pressure chamber by supplying a drive pulse, an acquisition portion that acquires output information regarding a usage condition of the head unit, a first connection portion that is communicably connected to a server through a network, a first output portion that outputs the output information through the first connection portion, a first input portion to which input information regarding a waveform of the drive pulse supplied to the drive element is input through the first connection portion. A decision portion that decides the waveform of the drive pulse supplied to the drive element based on the input information.

A liquid droplet discharging apparatus includes: a discharging head having: a liquid channel including a nozzle; and an energy applying part which applies, to liquid inside the liquid channel, discharge energy for discharging a liquid droplet from the nozzle; a signal outputting circuit which outputs signals depending on whether the nozzle satisfies a predetermined discharging performance; and a controller. The controller determines whether the nozzle satisfies the predetermined discharging performance, and estimates viscosity of the liquid inside the discharging head based on: viscosity estimation data in which discharge energy information and viscosity information are associated with each other, and a result of the determination performed in a case that the controller controls the energy applying part based on the discharge energy information and that the discharge energy is thereby applied to the liquid inside the liquid channel.