Hewlett-packard Development Company, L.p.

Marti Rius

Jan Morovic

Peter Morovic

Jordi Sender

Ramon Vega

Angel Martinez

Sergio Puigardeu

Alex Andrea

David Gaston

Silvia Miramanda

Marcos Casaldaliga

Joan Jorba

Carles Flotats

Lluis Hierro

Jose M Rio Doval

Jesus Garcia

M Isabel Borrell

David Soriano

Pep-Lluis Molinet

Isabel Borrell

Joan Joroa

Joaquim Brugu

Juan Garcia-Reyero

Examples describe a method in which first and second test patterns are printed onto a print medium. The first and second test patterns each vary in print density in opposing directions. A location is determined along the first and second test patterns having at least substantially equal visual density.

Print inconsistency quantification

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.

Method and printer for multi-pass page-wide array printing

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.

Defective nozzle replacement in a printer

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.

Printers and printhead cleaning primarily in page-wide array printers

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.

Serial bus system

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.

Method for automatic pen alignment in a printing apparatus

A hard copy device having a carriage arranged to support a printhead and to reciprocate across a scan axis, the device being arranged to determine the position of at least a part of the printhead along the scan axis, compensating for carriage rotation about the an axis orthogonal to the scan axis, by interpolating or extrapolating from carriage position information derived from first and second codestrips traversing the scan axis and spaced apart in a direction orthogonal to the scan axis.

Position measurement system and method

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Barcelona, Spain

Marti Rius