A discharge head includes an orifice surface in which orifices each configured to discharge a droplet are arrayed in a predetermined direction. A detecting unit includes a light emitting element and a light receiving element, and optically detects a droplet discharged from the orifice. A suppression unit is arranged between the light emitting element and the orifice surface, and suppresses the light emitted from the light emitting element from reaching the orifice surface by shielding at least some rays of the light which are emitted from the light emitting element and would otherwise propagate to the orifice surface.

A method and system for detecting one or more failing nozzles in an inkjet printhead of an inkjet printer for printing an image on a substrate and compensating failing nozzles, as well as for correcting colour uniformity of a printed image in inkjet printing an image on a substrate includes printing a first test pattern on a dedicated substrate, which is optically scanned and includes a system for the same. From the scan failing nozzles are identified, which are to be compensated by other nozzles. To these compensating nozzles compensated nozzle control data are allocated, which are used in printing a second test pattern that is also scanned and analysed for local deviations of colorimetric greyscale value. Corrected nozzle control data are allocated to the nozzles associated with the local deviation.

Provided are a fringe information measuring apparatus that measures information on a fringe region using a temperature sensor array and a substrate treating system including the same. The fringe information measuring apparatus comprises: a laser sensor configured to output a first laser light and a second laser light to intersect each other; a thermal sensor array configured to pass through a fringe region formed by the intersection of the first laser light and the second laser light; and a control module configured to measure a position of the fringe region based on information obtained when the thermal sensor array passes through the fringe region.

A liquid ejecting device includes: a liquid ejecting head configured to eject a liquid from a plurality of nozzles to perform printing; an imaging unit configured to image a nozzle surface at which the plurality of nozzles are provided; an ejection-failure detecting unit configured to detect whether the plurality of nozzles have an ejection failure; a maintenance unit configured to perform maintenance of the liquid ejecting head; a notification unit configured to perform notification; and a control unit, in which, when the ejection-failure detecting unit detects the ejection failure, the control unit causes the imaging unit to image a nozzle for which the ejection failure is detected, infers a cause of the ejection failure based on a result of the imaging, and performs at least one of the maintenance and the notification based on the inferred cause.

Systems and methods are provided for. One embodiment is a system that includes an interface configured to receive an image of media printed on with print data, and memory configured to store defect reference data of nozzles belonging to printheads of a printer. The system also includes a print defect controller configured to detect a nozzle defect in the image based on a comparison of the image with the print data, and to determine a type of the nozzle defect based on a comparison of the nozzle defect with the defect reference data.

A controller of a liquid ejection device is configured to receive a preparation signal instructing preparation to eject the liquid, the preparation signal being externally issued upon issuance of an ejection instruction to eject the liquid toward a target medium. The controller is configured to start receiving ejection data after the preparation signal is received, the ejection data being externally transmitted on condition that the ejection instruction is issued and after the preparation signal is issued. The controller is configured to control the liquid ejection head to eject the liquid toward the target medium through the multiple nozzles based on the ejection data. After receiving the preparation signal and before receipt of the ejection data is completed, the controller is configured to control the liquid ejection head to eject liquid through the multiple nozzles and examine at least a part of the nozzles for ejection-defectiveness based on the determination signal.

In a method and system for increasing print quality, activation pulses are activated with which a nozzle of an inkjet printing device to print dots on a recording medium. The activation pulses may be adapted based on sensor data with respect to already printed dots. The method and system can further include an automatic adaptation of the activation pulses to increase print quality even given the presence of soiling at the nozzle.

A machine learning method includes: obtaining a discharge parameter on discharging performed by a liquid discharge head discharging liquid; obtaining an image quality determination result produced by determining a printed image quality; and learning the relationship between the discharge parameter and the image quality determination result. Also, the discharge parameter desirably includes a discharge state value indicating a discharge state of the liquid discharge head and a discharge result value indicating a discharge result of the liquid discharged on a print medium from the liquid discharge head. The machine learning method includes learning the relationship between the discharge state value and the discharge result value, and the image quality determination result.

An inkjet printer includes solvent vapor generators that direct two flows of solvent vapor on each side of each printhead in the process direction toward media passing the printheads in the printer. The solvent vapor attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

A liquid discharge apparatus includes a plurality of liquid dischargers and circuitry. The plurality of liquid dischargers is configured to discharge liquids of a plurality of colors from discharge holes to form an inspection image on a recording medium. The circuitry is configured to detect a failure of the discharge holes, based on the inspection image formed on the recording medium with the liquids of the plurality of colors. The inspection image includes linear images of the plurality of colors extending in a first direction and arrayed in a second direction intersecting the first direction. Linear images of at least two colors, of the linear images of the plurality of colors, are positioned to overlap each other in the first direction.