Hewlett-packard Development Company, L.p.

Jacint Humet Pous

Eduardo Amela Conesa

Marc Serra Vall

Jaime Fernandez Del Rio

Jaime Fernández Del Rio

Johan Maurice Lammens

Juan Uroz Soria

Andreas Muller

Maria Elizabeth Zapata

Utpal Kumar Sarkar

Michel Georges Encrenaz

Miguel Angel Lopez Alvarez

Juan Uroz

Pere Gasparin Talarn

Andreas Müller

Jesús García Maza

Andreas Mueller

Marc Rossinyol Casals

Marc Serra Vail

A test chart having printed regions is output at respective ink densities. An indication of a selected ink density is received. One or more resources of a printing device are determined according to the selected ink density to control one or more ink limits and a color separation of the printing device.

Method and apparatus for print control

Certain examples of printers and methods of printing may involve determining colorant amounts of image regions within a print image.

Printer

Embodiments of the present invention provide a method for use in a printing device, comprising outputting a test chart comprising a plurality of printed regions at respective ink densities, receiving an indication of a selected ink density, and determining one or more resources of the printing device according to the selected ink density to control one or more ink limits and a color separation of the printing device.

Techniques related to printer calibration are disclosed herein. In an example, an actual measurement of a colorimetric parameter is performed by measuring the colorimetric parameter on a printed calibration pattern. The colorimetric parameter is associated with an ink drop number. The calibration pattern is printed with selected printing conditions. An ink drop number variation is determined from a reference measurement and the actual measurement of the colorimetric parameter. The reference measurement is a measurement of a colorimetric parameter. The reference measurement corresponds to a measurement of the colorimetric parameter on a calibration pattern printed with the selected printing conditions. An actual linearization is generated by validating a set of pre-defined linearizations with the determined ink drop number variation. Other examples of printer calibration are disclosed.

Printer calibration

Methods performed by a printing system are described herein. A portion of a print area is located by operating an optical sensor to respond to a color shift. The color shift is from a printed reference color. The color shift is caused by a fixer fluid applied to the portion. Printing systems and tangible machine readable storage mediums are also described herein.

Printing systems and methods for operating printing systems

An apparatus and method for controlling a printing device are described. In examples, a printing device has a first printhead interface, a first printhead for use in applying a treatment fluid to a print medium and a second printhead interface, a second printhead for use in applying ink to the print medium. The first and second printhead interfaces are consecutively aligned along a common axis and each printhead has a plurality of nozzles that extend in a direction of relative movement of the print medium in relation to said printheads. An example apparatus then has a controller arranged to, when the printheads are installed, configure activation of nozzles of at least one of the first and second printheads in the direction of relative movement to spatially offset useable nozzles of the first printhead with respect to useable nozzles of the second printhead in said direction.

Apparatus and method for controlling a printing device

The present disclosure is related to deposition of print treatments. In an example, treatment is to be deposited on substrate dot locations to receive ink according to selected treatment-to-ink regimes. The selected treatment-to-ink regimes include a variable treatment-to-ink regime and a constant treatment-to-ink regime. The variable treatment-to-ink regime is for depositing a variable amount of treatment dependent on the amount of ink to be deposited in a substrate dot location when the ink amount in the substrate dot location is below a threshold. The constant treatment-to-ink regime is for depositing a selected constant amount of treatment in a substrate dot location and an area surrounding the substrate dot location when the ink amount in the substrate dot location is above the threshold. Other examples are illustrated herein.

Deposition of print treatment

Application of treatments for treating a colorant for printing an image is described herein. In an example, an amount of a treatment to be applied on a substrate portion is determined considering color calibration of a printing system for specific conditions of printing the image. The treatment is for treating the amount of colorant on the substrate portion.

Techniques related to printing

An apparatus and method for use in printing a swath in a multipass printing device are disclosed. The method comprises selectively depositing a drop of ink associated with a pixel to be printed on a print media based on a substantially uniform print mask function during a first pass of a print head, and selectively depositing a further drop of ink associated with the pixel on the print media based on a ramp print mask function during a further pass of the print head.

Printing method and apparatus

A method performed by a printing system is described herein. A request is provided to a user to enter data related to print quality of a mark or marks printed on a portion of a background region. The background region includes an area or areas treated with a fixer fluid applied by a printhead. A user input is received associated to the request. A misalignment of the printhead is estimated in accordance with the user input. A printing system and a tangible machine readable storage medium are also described herein.

Printing systems and methods performed by printing systems

According to one example, a printer includes an inkjet printhead, and the printhead comprises nozzles through which printing fluid is ejectable during a pass of the printhead across a print zone. Processing printhead control data includes obtaining printhead control data describing pixel locations in an image to be printed on a media, and allocating, for a swath of the image, each of the pixel locations to a printhead nozzle and to a print pass of a set of print passes in accordance with a print mask. The print mask defines sections associated different groups of the nozzles.

Processing printhead control data and printing system

The optical density of a first primary color is determined using two test patches. The first patch is printed with only the first primary color and a second primary color. The second patch is printed using the first primary color and a second primary color. The optical density of both patches is measured. The optical density of the first primary color is determined using the measured optical density of the second primary color and the measured optical density of the first patch.

Printer calibration using measured and determined optical densities of different primary colors from test patches

According to one example, there is provided a method of calibrating a printing system. The printing system is configured to supply print media and calibration media to a print zone. The method comprises controlling the printing system to position calibration media in the print zone, printing a predetermined set of color patches on the calibration media, measuring color characteristics of the printed set of color patches, and comparing the measured color characteristics with a set of reference color characteristics. The method further comprises calibrating the printing system based on the compared characteristics.

In one embodiment, a print system includes an anticipated ambient lighting selector to allow selection of an anticipated ambient lighting. A rendering module is configured to map a print job into raster data configured to reduce color cast in gray output when displayed under the anticipated ambient lighting.

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Barcelona, Spain

Jacint Humet Pous