A liquid ejection apparatus includes a controller configured to perform: causing a voltage application circuit to apply a voltage between a liquid ejection head having a plurality of nozzles and an electrode; driving the liquid ejection head for causing a certain nozzle to eject liquid toward a cap in a state where the plurality of nozzles face the cap; receiving a signal from a signal output circuit; determining, based on the received signal, whether the certain nozzle has ejected liquid normally; determining, based on the received signal, whether a leakage current has occurred between the certain nozzle and the electrode; and specifying the certain nozzle as a leakage nozzle if the leakage current has occurred between the certain nozzle and the electrode.

Examples relate to a method to print a print job. The method comprise comparing an operational parameter of the print job with a reference operational parameter and determining to perform a maintenance task during the print job based on at least a result of comparing the operational parameter with the reference operational parameter. If the maintenance task is to be performed, the method further comprises determining a safety area on a printable medium and performing a maintenance task on a printable medium.

A processing device including a hardware processor that: determines a dot position at which a dot is to be generated by multiple recording elements arranged in a first direction on a medium which moves relative to the recording elements in a second direction crossing the first direction, based on tone data for each pixel of an image to be formed; determines a corrected dot number that is a number of a dot position by a malfunctioning recording element to which an offset number is added, wherein the malfunctioning recording element is set as a recording element by which a dot is not generated normally among the recording elements; and determines the corrected dot number of a dot position within a dot generation possible range by a recording element other than the malfunctioning recording element.

A printing system includes a controller. The controller is configured to: receive first condition information related to an ejection failure in a printer; determine a maintenance manner applicable to the first condition information; cause the printer to perform a maintenance in the determined maintenance manner; receive second condition information related to the ejection failure in the printer after the maintenance is performed; determine whether an ejection performance in the printer has been improved based on the second condition information in response to performing the maintenance; update an evaluation index in accordance with determination of whether the ejection performance in the printer has been improved, the evaluation index corresponding to the determined maintenance manner.

A method for compensating for failed printing nozzles in an inkjet printing machine uses a computer to provide an increased ink drop volume of adjacent nozzles. All existing printing nozzles are measured regarding print failure and deviation of a printed dot beyond a specific threshold, so that the printing nozzles are marked either as functioning, failed, or printing a dot deviating in a direction transverse to the printing direction, and the results are saved on the computer. The computer hides all functioning printing nozzles and marks all remaining isolated printing nozzles as failed nozzles. The computer groups adjacent remaining printing nozzles by marking nozzles printing a dot deviating in a direction transverse to the printing direction as functioning printing nozzles contributing to the compensation or as failed printing nozzles in accordance with a rule, and the computer compensates for all printing nozzles having been marked as failed.

A device for printing to a recording medium with an inkjet printing unit that has at least one nozzle arrangement and is designed to generate a print image on the recording medium. The print image includes at least one test pattern that exhibits at least two different spatial frequencies. The device also has an image acquisition unit that is designed to acquire an image of an acquisition region on the recording medium, which acquisition region includes at least a portion of the test pattern; and a processor that is designed to generate image data corresponding to the image and determine a functional state of the nozzle arrangement, by means of the image data, using a neural network.

Provided are a nozzle inspection unit configured to generate a large amount of defect data to improve detection accuracy of a defective nozzle, and a substrate treatment apparatus including the same. The nozzle inspection unit includes: a data collection module configured to collect a plurality of image data related to nozzles; a data classification module configured to classify the plurality of image data according to predefined classes; a data merging module configured to merge good image data related to a normal nozzle and defect image data related to a defective nozzle from among the plurality of image data; a data training module configured to train a plurality of merged image data obtained through the data merging module; and a defect data generation module configured to generate a plurality of final image data from the plurality of merged image data based on the training result.

There is provided a liquid discharge apparatus including: a head having nozzles; a conveyer; and a controller. The controller is configured to carry out a conveyance process of conveying a recording medium in a conveyance direction, and a discharge process of discharging a liquid from the nozzles to the recording medium. The discharge process includes a plurality of discharge steps carried out to a unit area of the recording medium based on data obtained by decomposing an image data into complementary patterns. In at least one of the discharge steps corresponding to the unit area, a function of a discharge duty of the nozzles has an ascending portion or a descending portion. The controller is configured to carry out before the discharge process: a detection process of detecting a defect nozzle in the nozzles; and in a case that the defect nozzle is detected, a change process of changing the function.

A recording method for performing recording on a medium by forming dots by ejecting a liquid from nozzles during scanning. The recording method includes detecting an abnormal nozzle; disposing a normal nozzle in a row where dot missing occurs due to the abnormal nozzle by moving a medium by a first moving amount; performing first complementary recording in which at least a part of a dot missing region is complemented by a first dot which is recorded by the normal nozzle during the scanning; moving the medium by a second moving amount; and performing second complementary recording in which a second dot of which a size is greater than a size of a dot determined based on printing data is recorded on a row adjacent to a row of the abnormal nozzle by the normal nozzle that is positioned adjacent to the abnormal nozzle during the scanning.

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.