Hewlett-Packard Development Company, L.p.

M Isabel Borrell

Sergio Puigardeu

Angel Martinez

Luis Garcia

Utpal Kumar Sarkar

Marc Serra

Leticia Rubio

Marcos Casaldaliga

Jordi Sender

Marti Rius

Ángel Martinez

Xavier Farina

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 printer for printing on a print medium as said print medium advances through a print zone, the printer including a number of print heads extending over the print zone, each print head including at least one nozzle array wherein at least two adjacent nozzle arrays overlap forming at least one stitching zone in the overlap region; and a printer controller for generating a sequence of nozzle firing commands for each nozzle array to selectively deposit droplets of print fluid on said print medium from said nozzle arrays in accordance with an image to be printed, wherein the printer controller further applies masks having decorrelated patterns to said sequence of firing commands for at least those overlapping nozzles of the nozzle arrays coinciding with the at least one stitching zone to obtain a predetermined optical parameter of the printed image in the stitching zone, irrespective of an offset between two adjacent nozzle arrays.

Printer and computer-implemented process for controlling a printer

Print image-quality defects are diagnosed by printing an image and one or more diagnostic patterns concurrently.

Concurrent image and diagnostic pattern printing

In a method for printing a plurality of pixels, each pixel of a plurality of pixels is printed by controlling an inkjet print head to provide for each pixel at least two ink drops at different positions in a print head movement direction, the print head having a plurality of trenches supplying ink to a plurality of sets of nozzles. The at least two ink drops forming first pixels of said plurality of pixels are fired from the same trench.

Inkjet printing apparatus and method for printing a plurality of pixels

In one embodiment, first printing is caused in response to a print job, applying ink upon a media utilizing a first row of printheads and a second row of printheads. The first row of printheads includes a plurality of printhead types. The second row of printheads is adjacent to the first row and includes at least one printhead of each of types. Failure of a first printhead within the first row is detected. The status of printheads included within the second row is analyzed. Second printing is caused applying ink upon the media utilizing the second row of printheads, and not the first row of printheads, in response to determining that printheads within the second row are operable to complete the print job.

Recovery print mode

A multipass printing method includes determining at the end of a printing pass if at least some dot depositing elements of at least one printhead require a servicing operation. In case the determination is positive, the method includes printing at least one incomplete printing pass in which at least the dot depositing elements of the at least one printhead that require a servicing operation are not operated to print. At the end of the incomplete printing pass, the method includes servicing at least the dot depositing elements of the at least one printhead and printing at least one compensating printing pass, which adds to the information to be printed in the compensating printing pass at least part of the information that failed to be printed by the dot depositing elements of the at least one printhead in the at least one incomplete printing pass.

Multipass printing method

Images selected for printing are assigned respective print-speed modes so that at least first and second of said images are assigned to a relatively fast print mode and at least a third image is assigned to a relatively slow print mode. The images are arranged as a function of print-speed mode so that said first and second images are in a first row and so that said third is in a second row. The images are then printed on real print media, with the first row being printed using a relatively fast print speed and the second row being printed at a relatively slow print speed.

Automatic arrangement of nested images as a function of assigned print modes

A roll-based printer and method of loading the same. An example method includes sliding a roll of print media onto a print media spindle so that the roll of print media is positioned closer to a first end of the print media spindle than a second end of the print media spindle and loading the spindle onto a supporting assembly so that the spindle is rotatably supported by the supporting assembly and the first end of the print media spindle is at the end of the printer which is opposite to an end of the printer having a media detecting unit for detecting the presence of print media being fed to the printer. The example method includes feeding the print media to the printer from the loaded spindle, detecting the position of an edge of the print media fed to the printer and adjusting a starting position of the print head based on the detected position of an edge of the print media.

Growing community of inventors

Barcelona, Spain

M Isabel Borrell