Hewlett-Packard Development Company, L.p.

David Vendrell Tornero

Carles Carmona Calpe

Utpal Kumar Sarkar

Xavier Quintero Ruiz

Javier Castro Soriano

Nestor Luid Pinol

David Peinado Gutierrez

Ferran Olivera Corpas

Maria Vila Abad

A pagewide array (PWA) print bar of a printing device prints a calibration pattern on a print medium. The print bar is nominally perpendicular to a media advancement direction in which the print medium advances relative to the PWA print bar during printing. An image of the printed calibration pattern is optically scanned, and a skew angle by which the PWA print bar deviates from true perpendicular to the media advancement direction is calculated based on the optically scanned image. The printing device is calibrated to compensate for the calculated skew angle during subsequent printing.

Calibration to compensate for print bar skew angle

In an example a method comprises operating, by a processor, on a first quantity that is proportional to a side of a parallelogram printed, at least in part, on a substrate by a fluidic die, the side of the parallelogram being substantially perpendicular to the direction of advancement of the substrate. The method further comprises operating, by a processor, on a second quantity and a third quantity, the second and third quantities respectively being proportional to the length of the lines bisecting the parallelogram. The method comprises calculating, by a processor, an angle that the fluidic die makes with the direction of advancement of the substrate based on the first, second, and third quantities.

Fluidic dies

A method is described in which a difference in height is determined between a current position and a calibration position of a printhead of a printer. An alignment value for the printhead is then determined based on the difference.

Determining alignment of a printhead

Examples relate to computer-implemented methods for a printing system comprising a printhead, and to printing systems. A method for a printing system comprises retrieving a stored first offset applied to the printhead to align the printhead, the first offset determined based on a first user input signal; and further aligning the printhead according to a further offset determined based on a further user input signal, the further offset indicating a difference from the first offset.

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Sant Cugat del Valles, Spain

David Vendrell Tornero