A method of printing an image with a printhead having spatially offset groups of drop ejectors, each group having a plurality of drop ejectors that are aligned substantially along a scan direction, includes enabling simultaneous firing of drop ejectors that are corresponding members of a first set of groups. Drop ejectors within each group of the first set are sequentially fired until each member of each group has had opportunity to fire. Corresponding drop ejectors of a second set of groups are simultaneously fired, and drop ejectors within each group of the second set are sequentially fired. Any additional groups of drop ejectors are likewise fired until all drop ejectors have had opportunity to fire during a first stroke. Drop ejectors are fired in subsequent strokes similar to the first stroke as the recording medium is moved relative to the printhead along the scan direction until printing is completed.

An inkjet printing method, performed by an industrial inkjet system to form a decoration layer, includes the steps of, printing copies of a decorative image with a printing unit on a substrate by transmitting consecutive bitmap rows of the decorative image to a printing unit, measuring dimensional changes in the substrate while printing copies of the decorative image, and compensating the dimensional changes while printing copies of the decorative image by one of: skipping at least one bitmap row of the decorative image upon dimensional expansion, or reprinting at least one bitmap row of the decorative image on the substrate upon dimensional shrink.

An image processing apparatus operable to generate data for printing an image onto a printing medium using a plurality of color materials. The apparatus generates a plurality of color image data corresponding to the plurality of color materials based on image data; generates multinary color data corresponding to a combination of the plurality of color materials based on the plurality of color image data; and generates quantized data corresponding to each of the plurality of color materials based on the multinary color data and a threshold matrix. The apparatus generates the quantized data such that a color difference between a generated color in a case where a shift in a relative printing position does not occur and a generated color in a case where a shift in a relative printing position occurs is small.

A device includes a head to perform an operation on a conveyed object; a head moving device to move the head in a width direction orthogonal to a conveyance direction of the conveyed object; a position detector to detect a position of the conveyed object in the width direction; a speed detector to detect a moving speed of the conveyed object in the width direction; a position predictor to obtain a predicted width position of the conveyed object after a predetermined period, based on a detected position of the conveyed object and a detected moving speed of the conveyed object; a speed calculator to calculate a travel speed of the head; and a head travel controller to control the head moving device to move the head at the calculated travel speed. With the calculated travel speed, the head arrives at the predicted width position after the predetermined period.

A head unit (51) includes a recording head (52), a frame (53), and an angle adjusting portion (8). The frame (53), to which the recording head (52) is rotatably connected, has a side wall (531) to be adjacent to the recording head (52). The angle adjusting portion (8) includes frame and head adjusting screws (81, 82) and rotates the recording head (52). The frame adjusting screw (81) is on the side wall (531), on its face opposite the recording head (52), and can reciprocate toward and away from the recording head (52). The head adjusting screw (82) is on the recording head (52), on its face opposite the side wall (531), and can reciprocate toward and away from the side wall (531). The frame and head adjusting screws (81, 82) make contact with each other at their tip end parts in the direction in which they face each other.

A three dimensional printer is configured to move at least one printhead from an area where the printhead is forming an object to a position opposite a shaft. The at least one printhead is operated to eject material onto the shaft and the shaft is rotated to enable a light sensor to generate signals indicative of a height of material at a plurality of positions on the shaft. The signals are compared to an expected height of material at each position to identify inoperative inkjets in the at least one printhead.

A method for detecting printing nozzle errors in an inkjet printing machine provides a high degree of robustness in the detection of errors by printing a nozzle test pattern in the inkjet printing machine. The test pattern is then digitalized by using a camera and transmitted to a computer for evaluation. There, the recorded test pattern is investigated by using methods of digital image processing, such as a Fourier analysis, and evaluated in the frequency range with regard to specific anticipated printing nozzle errors. Specific printing nozzle errors can be detected especially on the basis of amplitude, phase and variance errors in the signal in the frequency range. Moreover, by using the phase error, it is possible to evaluate whether the two print heads are disposed in an incorrect adjustment position relative to one another by calculating displacements of the phase error in transition regions of two print heads.

Mechanisms for adjusting the position of one or more print heads at an extremely fine resolution (e.g., less than 10 μm) are described herein. The adjustment mechanisms include a differential screw and an indexing wheel through which the differential screw extends. One threaded segment of the differential screw is connected to a threaded feature of a flexible body that is coupled to the print head(s), while another threaded segment of the differential screw is connected to a threaded feature of a rigid body that is coupled to a printer assembly. As the indexing wheel and differential screw rotate, the space between the flexible body and the rigid body changes based on the difference between the pitches of the threaded segments. The adjustment mechanisms described herein utilize the accurate, consistent motion of the flexible body upon experiencing pressure to effect predictable changes in the position of the print head(s).

Disclosed is an industrial single-pass inkjet printer/press incorporating an line-scan camera. The line-scan camera enables system software to inspect every sheet for quality assurance purposes. These inspection results are tied back to a digital printer to take one or more of several possible actions. Actions include ensuring a particular number of acceptable prints are generated and sorted. Actions further include performing nozzle checks without pausing or interrupting production orders.

A liquid discharger includes a head including nozzles to discharge liquid from the nozzles, a detachable first container attached to the liquid discharger to accommodate the liquid, a second container connected to the head to accommodate the liquid to be supplied to the head, a supply channel to connect the first container and the second container, an irreversible pump connected to the second container, and a controller to control the irreversible pump to pressurize and decompress the second container to reciprocally move the liquid between the first detachable container and the second container via the supply channel.