Abstract: An apparatus and method for use in generating calibration parameters for an inkjet nozzle are disclosed. The method comprises obtaining data defining how calibration parameters associated with a nozzle change as the number of ink drops ejected from a nozzle increases, determining a number of ink drops ejected from the nozzle, and adjusting calibration parameters for the nozzle based on the determined number of ink drops ejected from the nozzle and the obtained data defining how calibration parameters associated with a nozzle change as the number of ink drops ejected from a nozzle increases.

Abstract: The invention relates to a method of controlling a printer, the printer having an array of nozzles which extends across a print zone of the printer, the method comprising the steps of: evaluating a nozzle status of the array of nozzles; printing a first swath across the print media in the print zone, wherein the array of nozzles is located in a first position during printing of the first swath; determining a second position of the array of nozzles for printing a second swath so that, under consideration of the determined nozzle status, the combined output of the first and second swaths meets a predetermined criterion; moving the array of nozzles to the determined second position and printing the second swath across the print media in the print zone.

Abstract: Image processing for printing comprises identifying regions of an input image having characteristics of distinct printing requirements; classifying each pixel within each identified region based on the characteristic of the identified region; applying a colour mapping to each pixel according to the classification of the pixel to optimize each color mapping in accordance with at least one of plurality of attributes.

Abstract: A method for printing with a printhead, comprising: generating a first imaging matrix comprising cells each containing information related to the ink to be deposited on a corresponding area of the print medium; on the basis of said first matrix, generating a second imaging matrix, comprising cells each containing information related to the ink drops to be deposited on a corresponding area of the print medium; wherein some cells of the second matrix are prioritized and for some of them the information related to the ink drops depends on a cell of the first matrix that corresponds to a different area of the print medium than the area of said prioritized cell of the second matrix; such that upon printing, nozzles of the printhead associated with some prioritized cells fire ink that in the first matrix is associated with areas of the print medium corresponding to non-prioritized cells.

Abstract: A method for printing, comprising: obtaining an imaging matrix, in which each row or each column of cells is associated with at least a nozzle of a printhead, and in which each cell contains an initial value of a parameter which is related to an amount of ink to be deposited on the print medium; dividing the imaging matrix into at least two subsets of cells, such that each cell of the matrix belongs to one of said subsets; associating with each subset of cells a conversion function; obtaining a converted imaging matrix by applying to the initial value in each cell the function that corresponds to the subset to which the cell belongs; and printing using said converted imaging matrix.

Abstract: The invention relates to a fluid ejection system comprising a print head unit including a fluid ejection nozzle array, wherein the fluid ejection nozzle array comprises at least a first set of nozzles having nozzles of a first fluid ejection capacity and a second set of nozzles having nozzles of a second fluid ejection capacity and nozzles of a third fluid ejection capacity, wherein the first fluid ejection capacity, the second fluid ejection capacity and the third fluid ejection capacity are different from one another, and further including a printer controller which, in a first printing mode, selects nozzles of the first and second sets for firing in proportions so that the overall color densities generated by the nozzles of second set when compared to nozzles of the first set are the same in a defined print area.

Abstract: A method and system of controlling at least one printbar in a printing system are described. The printing system has one or more of printbars (160, 190) distributed along a media transport. A first image including a reference pattern (240A, 240B) is generated on a print medium (150) with a first printbar (160). A detector (180) then detects a pattern on the print medium. The reference pattern and the detected pattern are used to determine a position of the first image relative to a second printbar (190). This position is used to configure nozzle data for a second image to be generated on the print medium by the second printbar.

Abstract: The invention relates to a method of controlling a printer, the printer having an array of nozzles which extends across a print zone of the printer, the method comprising the steps of: evaluating a nozzle status of the array of nozzles; printing a first swath across the print media in the print zone, wherein the array of nozzles is located in a first position during printing of the first swath; determining a second position of the array of nozzles for printing a second swath so that, under consideration of the determined nozzle status, the combined output of the first and second swaths meets a predetermined criterion; moving the array of nozzles to the determined second position and printing the second swath across the print media in the print zone.

Abstract: A densitometer includes a plurality of light-emitting diodes (LEDs) and at least one sensor. The LEDs are activated one at a time in a sequential, repeatable order. Photonic energy from each LED is reflected off an entity and is incident upon the sensor(s). Circuitry samples or acquires signaling from the sensor(s) in accordance with the respective LED activations. Signaling from the densitometer can be used in controlling ink-jetting printers or other apparatus.

Abstract: A densitometer includes a plurality of light-emitting diodes (LEDs) and at least one sensor. The LEDs are activated one at a time in a sequential, repeatable order. Photonic energy from each LED is reflected off an entity and is incident upon the sensor(s). Circuitry samples or acquires signaling from the sensor(s) in accordance with the respective LED activations. Signaling from the densitometer can be used in controlling ink-jetting printers or other apparatus.

Abstract: The invention relates to a fluid ejection system comprising a print head unit including a fluid ejection nozzle array, wherein the fluid ejection nozzle array comprises at least a first set of nozzles having nozzles of a first fluid ejection capacity and a second set of nozzles having nozzles of a second fluid ejection capacity and nozzles of a third fluid ejection capacity, wherein the first fluid ejection capacity, the second fluid ejection capacity and the third fluid ejection capacity are different from one another, and further including a printer controller which, in a first printing mode, selects nozzles of the first and second sets for firing in proportions so that the overall color densities generated by the nozzles of second set when compared to nozzles of the first set are the same in a defined print area.

Abstract: A printing device configured to print a diagnostic plot, the diagnostic plot including a cockle pattern, a main media advance pattern, and a secondary media advance pattern, wherein the cockle pattern, main media advance pattern, and secondary media advance pattern are for providing feedback and for adjusting printing characteristics associated with the printing device. A method of adjusting vacuum levels in a vacuum system of a printing device including generating a diagnostic plot on media; the diagnostic plot including a cockle pattern, a main media advance pattern, and a secondary media advance pattern, and accepting adjustments to printing parameters on the printing device based on printing defects displayed on the diagnostic plot.

Abstract: A printing device configured to print a diagnostic plot, the diagnostic plot comprising a cockle pattern, a main media advance pattern, and a secondary media advance pattern, wherein the cockle pattern, main media advance pattern, and secondary media advance pattern are for providing feedback and for adjusting printing characteristics associated with the printing device. A method of adjusting vacuum levels in a vacuum system of a printing device comprising generating a diagnostic plot on media; the diagnostic plot including a cockle pattern, a main media advance pattern, and a secondary media advance pattern, and accepting adjustments to printing parameters on the printing device based on printing defects displayed on the diagnostic plot.

Abstract: A method of printing an image on a substrate using a page-wide-array printer and a page wide array printer is provided. The method includes printing a first portion of the image as relative movement occurs between the substrate and the print heads, and printing a second portion of the image as relative movement occurs between the substrate and the print heads, such that there exists an area of overlap between the first portion of the image and the second portion of the image. The substrate may be moved in a first direction relative to the print heads whilst the first portion of the image is printed, moved in a second direction opposite to the first direction; and moved in the first direction again whilst the second portion of the image is printed. The substrate may be printed whilst the substrate is moved in the second direction.

Abstract: A method of printing on a substrate and a printer are provided. The method uses a printer comprising a print head and a mask having a hole therethrough, the mask being disposed between the print head and the substrate, and comprises aligning the hole with the print head; printing on the substrate through the hole; and misaligning the hole with the print head so that the print head is covered by the mask. The method may allow the servicing of a print head in the array while the printer is printing on the substrate using at least one of the remainder of the print heads in the array.

Abstract: Printing is performed at a full resolution using a first set of nozzles and a second set of nozzles arranged on a printhead. Printing is performed at less than the full resolution using the first set of nozzles less any nozzles in the first set of nozzles that have been determined to be defective. The second set of nozzles is not used for printing at less than the full resolution except for a subset of nozzles in the second set of nozzles that are used to replace nozzles from the first set of nozzles that have been determined to be defective.

Abstract: A method of printing on a substrate in a page-wide array printer comprises printing on the substrate as the substrate is moved through a printing zone of the printer in a first direction, and printing on the substrate as the substrate is moved through the printing zone in a second direction different to the first direction.

Abstract: A serial bus system for data communication between devices according to a master-slave protocol has a data bus connecting master and slave devices and a shared clock system arranged to provide a shared-clock signal to the master and slave devices. The master and slave devices are arranged to derive device-individual clock signals which are synchronized with data received on the data bus, from the shared-clock signal and a data-timing indication on the data bus.

Abstract: A method for automatic pen alignment in a printing apparatus, wherein the printing apparatus has a scan direction or x-axis and a media advance direction or y-axis, orthogonal to said scan direction or x-axis, the method comprising the steps of performing a pen alignment process, determining an alignment correction algorithm to be applied during subsequent printing, to compensate for the misalignment determined in said pen alignment process, measuring an output angle of the media, defined as the angle between the y-axis and the actual direction of advance of the media, with at least one optical sensor arranged stationary on the printing apparatus, and employing the measured output angle to modify the alignment correction algorithm to be applied during subsequent printing.

Abstract: A method of printing an image on a substrate using a page-wide-array printer and a page wide array printer is provided. The method comprises printing a first portion of the image as relative movement occurs between the substrate and the print heads, and printing a second portion of the image as relative movement occurs between the substrate and the print heads, such that there exists an area of overlap between the first portion of the image and the second portion of the image. The substrate may be moved in a first direction relative to the print heads whilst the first portion of the image is printed, moved in a second direction opposite to the first direction; and moved in the first direction again whilst the second portion of the image is printed. The substrate may be printed whilst the substrate is moved in the second direction.