An ink-jet recording apparatus, including: a recording head including a first nozzle communicating with a first chamber storing a first ink and a second nozzle communicating with a second chamber storing a second ink whose viscosity change rate differs from the first ink; and a controller configured to determine a drive voltage to be a first voltage and determine voltage application timings for the respective first and second nozzles to be a first timing when estimated viscosity of the first ink is lower than a first viscosity and to determine the drive voltage to be a second voltage higher than the first voltage, determine the voltage application timing for the first nozzle to be the first timing, and determine the voltage application timing for the second nozzle to be a second timing different from the first timing when the estimated viscosity is equal to or higher than the first viscosity.

A liquid ejecting apparatus is configured to record a pattern group including a first pattern and a second pattern by driving a moving mechanism to perform a relative movement between a head and a recording medium and by driving the head to eject liquid towards the recording medium. The first pattern and the second pattern are recorded at different timings. Further, recording of the second pattern is performed when a temperature of the liquid in the head is temperature T2 which is different, by a target temperature difference or more, from temperature T1 which is a temperature of the liquid when the first pattern is recorded.

A method of operating a droplet ejection device including an ejection unit arranged to eject droplets of a liquid and including a nozzle formed in a nozzle face, 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, includes detecting low-viscosity liquid on the nozzle face by analyzing a signal obtained from the transducer.

A droplet discharging apparatus includes: a droplet discharger including a pressure chamber, an actuator and a nozzle provided corresponding to the pressure chamber, and a discharge flow path coupled to the pressure chamber, the droplet discharger performing a recording process by discharging liquid in the pressure chamber from the nozzle in the form of droplets; and a return flow path coupled to the discharge flow path and forming a circulation path. The droplet discharging apparatus performs as a maintenance operation for the droplet discharger, a first discharge operation of causing the liquid in the pressure chamber to be discharged toward the return flow path via the discharge flow path when no droplets are discharged from the nozzle during the recording process.

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 performs determination as to 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.

An inkjet image forming apparatus, includes: a transfer part that transfers ink ejected from an inkjet head and carried on an intermediate transfer body to a recording medium; and a hardware processor that: detects a transfer rate when the ink is transferred by the transfer part; and controls a control parameter that influences how the ink spreads when being transferred to the recording medium, according to the transfer rate detected by the hardware processor.

A jetting device configured to jet one or more droplets of a viscous medium through a nozzle may include an acoustic transducer configured to emit an acoustic signal that transfers acoustic waves into at least a portion of the viscous medium located in a viscous medium conduit a viscous medium conduit configured to direct a flow of the viscous medium to an outlet of the nozzle. The acoustic signal may be an ultrasonic signal. The acoustic signal may adjust one or more rheological properties of the viscous medium, based on acoustic actuation. The acoustic transducer may be implemented by an actuator of the device that is configured to move through an eject chamber to cause viscous medium to be jetted through the outlet of the nozzle as one or more droplets.

A head unit control circuit controls a head unit. The head unit includes: an ejector, a determination circuit, and an ejection limit circuit. The injector includes a displaceable piezoelectric element. The piezoelectric element is displaced by changing a drive signal potential. The determination circuit determines whether the piezoelectric element has a predetermined electrical storage capability. The ejection limit circuit stops the drive signal to limit the ejection of the liquid based on the determination. The head unit control circuit supplies an instruction signal, a first designation signal, and a second designation signal to the head unit. The instruction signal instructs the head unit to execute the determination. The determination circuit executes the determination during a period in which the first designation signal is set to a high level, the second designation signal is set to a low level, and the instruction signal is supplied.

A method for detecting an operating state of an ejection unit during the printing of an object of a print job the method comprising determining whether the ejection unit is in an operative state or in a malfunctioning state by analyzing a residual pressure wave generated in the liquid in a duct of the ejection unit by an actuation pulse. Further, the method comprises scanning the location of a recording medium onto which liquid has been ejected in order to perform an additional determination of whether the ejection unit is in an operative state or in a malfunctioning state. The method uses both determinations to build feedback information in the form of labeled data that is used in subsequent executions to improve the result of the determinations performed by analyzing a residual pressure wave generated in the liquid. Other aspects of the present invention relate to a droplet ejection device comprising a plurality of ejection units, as well as a printing system comprising the droplet ejection device, and a software product comprising program code on a machine-readable non transitory medium for executing the method in the printing system.

A printing apparatus which includes a circulation route configured to supply ink stored in a storage unit to a print head via a supply passage and send back the ink collected from the print head to the storage unit via a collection passage and which performs printing on a print medium by ejecting the ink from the print head includes: a first detection unit which detects an ink concentration in the collection passage; an injection unit which injects a correcting liquid capable of correcting the ink concentration into a circulated ink flow downstream of a position where the first detection unit detects the concentration in the collection passage; and a control unit which obtains an injection amount of the correcting liquid based on the concentration detected by the first detection unit and controls the injection unit such that the correcting liquid is injected in the injection amount.