An image forming apparatus includes a recording head that ejects inks of different colors on a recording medium to form an image based on image data, a storage device that stores a plurality of different dot patterns for flushing, and a control device that functions as: a controller that allows the recording head to make flushing; an image area detector that detects an image area in the image data; an overlapping dot counter that counts a number of overlapping dots for each of the plurality of dot patterns according to which flushing is to be made on the image area, the number of overlapping dots being a number of dots in the dot pattern of the ink ejected on the image area; and a dot pattern assignor that assigns, according to the number of overlapping dots, the respective dot patterns for use in flushing with the inks of different colors.

A technique includes printing a first image including a plurality of edge pixels and a second image with a lower ratio of edges pixels than the first image and an average density equal to that of the first image and determining a value of a processing parameter so that the average densities of the first image and the second image match. The technique is configured to realize appropriate pre-print processing while preventing the average densities from being low due to the excessive pre-print processing or being high due to the insufficient pre-print processing.

An ink-jet recording apparatus includes a recording unit, a scanning unit, an acquisition unit, and a determination unit. In the recording unit, a plurality of nozzles to apply ink is arrayed. The scanning unit is configured to perform relative scanning with the recording unit on a recording medium. The acquisition unit is configured to acquire input image data that includes a bar code including a plurality of black bars and a plurality of white bars and having a length in a first direction that is greater than a length in a second direction crossing the first direction. The determination unit is configured to determine, based on lengths of the plurality of white bars in the second direction, an amount of ink to be applied to a black bar adjacent to a corresponding white bar in the second direction.

A liquid dispensing element is provided. The element comprising; a dispensing plate comprising a plurality of orifices; the dispensing plate at least partially defining a fluid flow path; a plurality of piezoelectric transducers each comprising a piston configured to move perpendicular to the dispensing plate between a first position wherein the piston is close to the dispensing plate and a second position wherein the piston is further from the dispensing plate. The movement between the first and second positions results in the ejection of a droplet of fluid via a surface cavitation droplet ejection process such that the diameter of the droplet is less than a diameter of the orifice.

There is provided a printing apparatus including: a head having nozzles aligned in a first direction, a manifold, and a driving element; a first temperature sensor configured to detect, in the manifold, a temperature difference between a temperature of the ink at an upstream in the first direction and a temperature of the ink at a downstream in the first direction; and a controller. The nozzles have a first nozzle and a second nozzle. The controller is configured to execute: causing of the head to perform printing, and performing of position correction of correcting a discharge timing of the ink from the nozzles based on the temperature difference so that a distance between a landing position of the ink discharged from the first nozzle and a landing position of the ink discharged from the second nozzle becomes short in a second direction crossing the first direction.

A method of operating a printer extends the print zone of the printer by separating at least two printhead modules in the print zone by a distance that is greater than a width of a printhead module. The printhead modules are operated to print multiple color separations of an ink image and operates an optical sensors generates image data of the printed multiple color separations. The image data of the printed color separations are used to adjust distances between printhead modules in the print zone.

In an example implementation, a method of dual and single drop weight printing includes operating a printing system in a hybrid drop weight print mode to enable ejecting black ink from high drop weight nozzles and low drop weight nozzles, and ejecting color ink from high drop weight nozzles but not from low drop weight nozzles.

A liquid discharge apparatus includes a head and circuitry. The head discharges liquid to apply the liquid to an application surface. The circuitry controls discharge of the liquid from the head based on a vertical height of an application position at which the liquid is applied on the application surface.

The present disclosure relates to a printhead control system for a printer, wherein the printer includes at least one printhead comprising a plurality of nozzles for ejecting printing fluid, wherein the nozzles include high drop weight nozzles and low drop weight nozzles ejecting drops of different drop weight, and are each arranged to eject printing fluid on a print medium such as to print images in frame areas of the print medium and such as to clean nozzles in spit bar areas of the print medium; the printer further includes a transport unit for moving the print medium relative to the printhead, wherein the print medium includes frame areas for printing images and spit bar areas for cleaning the nozzles; the printhead control device including: a module to determine a first group of said nozzles located over a frame area of the print medium and a second group of said nozzles located over a spit bar area of the print medium; a module to operate the high drop weight nozzles of the first group such as to eject printing fluid and print an image in the frame area; a module to operate disable the low drop weight nozzles of the first group such as to not eject printing fluid in the frame area; and a module to operate the high drop weight nozzles and the low drop weight nozzles of the second group such as to alternately eject printing fluid in the spit bar area.

A measurement method of nozzle overlapping width, in a main scanning direction intersecting a conveying direction of a recording medium, in an inkjet recording apparatus including a plurality of heads each having a plurality of nozzles that eject ink, includes a first step (S120), a second step (S130), and a third step (S140). The first step (S120) includes forming an image for measurement on the recording medium, using image data including combination patterns of droplet sizes, different with respect to each of blocks extending along the main scanning direction. The second step (S130) includes selecting the block having uniform density along the main scanning direction, in the image for measurement. The third step (S140) includes determining the nozzle overlapping width using a droplet size ratio adopted to form the image for measurement, on a basis of a position of the selected block.