Memjet Technology Limited

Rodney Hardy

Brian Robert Brown

Julie Catherine Hogan

Ronan Palliser

James Lawrence

Juliette Le Hir

Keshu Nazneen

John Robert Sheahan

Angus John North

Philip Palma

Caitriona Forbes

Peter Allworth

Nigel Hoschke

Kieran Roughan

Steven Parker

David Keeshan

William Jacob

Colin Pickup

Julie Hogan

A method of printing an image from a print chip having plurality of horizontal nozzle rows. The method includes the steps of allocating first dot data for an image line of the image to nozzles in a first row portion of a first nozzle row; allocating second dot data for the image line to nozzles in a second row portion; sending the first and second dot data to the print chip and firing respective droplets. Some bits of the first dot data correspond to pixels of the image line aligned with the second row portion, and some bits of the second dot data correspond to pixels of the image line aligned with the first row portion.

Method of monochrome printing at high speeds

A method of printing an image using a printing system having first and second printheads supplied with a same ink. The method includes the steps of: allocating first lines of the image to the first printhead; allocating second lines of the image to the second printhead; dithering the first lines of the image using a selected first dither mask; dithering the second lines of the image using a selected second dither mask; printing the dithered first lines of the image using the first printhead; and printing the dithered second lines of the image using the second printhead. The first and second dither masks are selected based on a relative alignment of the first and second printheads.

Dither mask selection for printing using aligned printheads

A method of printing an image from a printhead module having a plurality of horizontal nozzle rows, the method including the steps of: allocating first dot data for an image line of the image to nozzles of a main row portion of a first nozzle row; allocating second dot data for the image line to nozzles of a dropped row portion of a second nozzle row; and sending the first and second dot data to the printhead module and firing respective droplets. Each nozzle row of the printhead module has a same number of nozzles N; and the first nozzle row and the second nozzle row are non-corresponding nozzle rows, such that a number of nozzles contained in the main portion of the first nozzle row and a number of nozzles contained in the dropped row portion of the second nozzle row is greater or fewer than N nozzles.

Mismatched nozzle rows for single-pass monochrome printing at high speeds

A method of printing an image from a printhead module having a plurality of horizontal nozzle rows. The method includes the steps of: allocating first dot data for an image line of the image to nozzles in a main row portion of a first nozzle row; allocating second dot data for the image line to nozzles in a dropped row portion of the first nozzle row; sending the first and second dot data to the printhead module and firing respective droplets. Some bits of the first dot data correspond to pixels of the image line aligned with the dropped row portion, and some bits of the second dot data correspond to pixels of the image line aligned with the main row portion.

Ramping dot data for single-pass monochrome printing at high speeds

A print medium having a calibration pattern printed thereon for generating alignment data for a printhead. The calibration pattern contains rows of spaced apart fiducials, each fiducial having a plurality of concentric shapes representing a Barker code.

Print medium for generating printhead alignment data

A method of single-pass printing uses a printing system having first and second aligned printheads supplied with a same ink. The method includes the steps of: receiving first and second halftone images at the first and second printheads, respectively; printing the first halftone image from the first printhead; and printing the second halftone image from the second printhead. The first halftone image is based on a first dither pattern and the second halftone image is based on a second dither pattern, the first dither pattern being different than the second dither pattern.

Method of dithering for high-speed single-pass printing

A method of processing a contone image for single-pass printing uses a printing system having first and second aligned printheads supplied with a same ink. The method includes the steps of: providing the contone image at a first resolution in a printing direction; dithering the contone image using a combined dither pattern to provide a full halftone image at the first resolution; dividing the full halftone image into first and second halftone images at a second resolution in the printing direction, the second resolution being less than the first resolution; and sending the first and second halftone images to respective first and second printheads for printing. The combined dither pattern is a combination of a first dither pattern for the first printhead and a second dither pattern for the second printhead, the first dither pattern being different than the second dither pattern.

High-speed single-pass printing using combined dither pattern

A method of generating alignment data for a printhead. The method includes the steps of: printing a calibration pattern using the printhead, the calibration pattern including rows of spaced apart fiducials, each fiducial having a plurality of concentric shapes representing a code sequence; imaging the fiducials at a first resolution to generate imaged fiducials; cross-correlating a template fiducial with the imaged fiducials at a plurality of different displacement s relative to each imaged fiducial, the template fiducial having a configuration matching the imaged fiducials; determining a two-dimensional set of cross-correlation values for each imaged fiducial, each set of cross-correlation values indicating a center of a respective fiducial; and generating alignment data for the printhead using the sets of cross-correlation values.

Method of generating alignment data for printheads

A method of generating print data for an inkjet printhead having a plurality of ink planes. The method includes the steps of: receiving image data for a print job in a printer controller; retrieving keep-wet pattern data for each ink plane of the printhead, the retrieved keep-wet pattern data being determined using one or more input parameters; generating first print data for each ink plane in the printer controller based on the received image data; merging the first print data with the keep-wet pattern data to provide second print data for each ink plane; and sending the second print data from the printer controller to the printhead, thereby causing the printhead to print an image together with a keep-wet pattern. The keep-wet pattern is defined by a plurality of dots printed at a frequency sufficient to maintain hydration of each nozzle in the printhead.

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North Ryde, Australia

Rodney Hardy