Hewlett-packard Development Company, L.p.

Juan Uroz Soria

Antonio Gracia Verdugo

Jordi Arnabat Benedicto

Oriol Borrell Avila

Emilio Angulo Navarro

Jacint Humet Pous

Francisco Javier Pérez Gellida

Pere Gasparin Talarn

Jan Morovic

Francisco Javier Perez Gellida

Santiago Sanz Ananos

Gonzalo Gaston Llado

Jacint Humet

Miguel Angel Lopez Alvarez

Marina Ferran Farres

Ana Maria Cardells Tormo

Examples are provided to methods to dynamically control the timing of a printing fluid drop ejection to deposit printing fluid on a print zone of a substrate. The examples may also provide measuring a height profile of a pre-print zone.

Controlling printing fluid drop ejection

Example implementations relate to color compensation. Some examples may print a calibration target background on a non-opaque media. The calibration target background may have a color that increases a dynamic range of a set of color measurements of a calibration target foreground. Some examples may print the calibration target foreground over the calibration target background. Additionally, some examples may measure an optical density of the calibration target foreground with a reflective sensor and may calibrate a printer based on the measured optical density.

Color calibration

A method is described in which a first color is detected at a user-selected arbitrary position of a first print; a second color is detected at a user-selected arbitrary position of a second print printed by a printer; a color difference between the first color and the second color is determined; and settings of the printer are changed to reduce the color difference in further prints printed by the printer.

Color correction in printing systems

A detector device is disclosed for detecting an edge of a medium in a media processing system, the detector device comprising a spectrophotometer and a processing unit, the spectrophotometer scanning a medium in a media processing area and generating an output tuple, the processing unit comparing the output tuple to at least one reference tuple for detecting an edge of a medium. A printing system and method of detecting an edge of a medium in a media processing system are also disclosed.

Edge detector

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

A measured distance is received from a distance sensor, where the measured distance is indicative of a distance between a color sensor and a substrate. Using the measured distance, a location of a given projection of projections of a substrate support is determined. A color of a color patch on the substrate at the determined location of the given projection is determined.

Determining a color of a color patch

Techniques related to printing are described herein. According to an example, color patches are to be printed on a substrate. The substrate can be positioned on a substrate support for operation of a color sensor in a color measurement zone. Dimension and location in the substrate of the color patches are selected such that, for each color patch, at least a portion of the color patch can be positioned on a support projection in the color measurement zone. In some examples, color analysis techniques are described.

Color analysis

Techniques related to color analysis are disclosed herein. In an example, substrate locations on a printed pattern are selected based on a set of measurements related to substrate-height. Further, color of the printed pattern is determined at the selected locations.

A printing system with adaptive printhead temperature control, comprises a least one printhead for inkjet printing; heating means to heat said printhead or ink in said printhead to a predetermined temperature range; and control means to analyze content information of a print job to be printed, wherein said control means sets said predetermined temperature range and sets a heating power of said heating means at a given position of said printhead in accordance with content information relating to an entire print page of said print job, or a plurality of print pages of said print job.

System and method for adaptive printhead temperature control

A method of calibrating a printer is disclosed. The printer prints a plurality of patches using know color values. At least two patches of each color are printed. The patches are measured to determine a measured color value for each patch. The measured color values are checked for validity. The printer is calibrated using only the valid measured color values.

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

An ink patch is printed on a swath of media, by an inkjet-printing mechanism of an inkjet-printing device. Printing the ink patch takes a first length of time. The ink patch printed on the swath is heated at a first temperature less than a second temperature specified for the first length of time the inkjet-printing mechanism takes to print the ink patch. A second length of time is waited. A total length of time the swath is heated is at least substantially equal to the first length of time plus the second length of time.

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Terrassa, Spain

Juan Uroz Soria