Hewlett-packard Development Company, L.p.

Li Qian

Secundino Vicente Vicente

Eduardo Amela Conesa

Xavier Domingo Reguant

Francisco Guerrero Carvajal

Francesc Ros Cerro

Marian Dinares Argemi

Xavier Domingo

Maxime Rosello

David Ramirez Muela

Francisco Guerrero

Macia Sole Pons

Marc Bautista Palacios

Chandrasekhar Nadimpalli

Diego Lopez Ubieto

Andrei Alexandru Dafinoiu

Carles Carmona Calpe

Pere Gasparin Talarn

Maurizio Bordone

Carles Ruiz Floriach

Javier Castro Soriano

Marc Bautista

David Munoz Navarro

Oscar Martinez Bailac

Andreas Müller

Annarosa Multari

Guillem Roig

Alfonso Sanchez

Ruben Recasens Oros

Macià Solé Pons

David Ramírez Muela

Mihail Zverev

Jamie Juan Munoz

Jaime Juan Munoz

Andreas MÜLLER

Examples include a method for mitigating decap in a printing system that comprises nozzles, in which printing data associated to a graphical representation and that comprise pixel data points are received. Some data points are associated with a corresponding nozzle and a corresponding direction of movement and at least one specific data point is associated with a specific direction of movement and a specific nozzle which has a decap time below a first predetermined threshold. The received printing data is modified by displacing the printing data of the specific data point in a direction opposite to the specific direction of movement in order to compensate for the decap time.

Decap time and printing data

An optical sensor device () includes an application module () for applying an irregular pattern of marks to a surface of a medium and an optical detector module (). The optical detector module () acquires images of the applied marks and may determine an advancement speed of the medium based on the acquired images.

Applying marks to a surface of a medium

In an example, there is provided a method and apparatus for controlling spit on page operation, the method comprising receiving at least one image to be printed, for each row of a plurality of rows of the image: identifying two or more pixels of the row of the image to be printed by a nozzle of a printhead, determining if a spacing between two consecutive pixels of the two or more pixels is greater than a threshold distance, and in response to a determination that the spacing between the two consecutive pixels is greater than the threshold distance, providing an indication that spit on page dots should be provided when printing the image.

Method and apparatus for printhead maintenance

A print apparatus is disclosed. In some examples, the print apparatus comprises a print head to deposit print agent onto a substrate; a detector to detect a fiducial; a first light source to back-illuminate the substrate, such that light from the first light source is to be detected by the detector through the substrate; and processing apparatus. The processing apparatus is to operate the print head to deposit print agent to form a first fiducial on a first side of the substrate, the first fiducial comprising a shape of a first colour and having a first dimension, and a background of print agent of a second, different colour, wherein the first dimension of the shape does not exceed a corresponding dimension of the background; operate the print head to deposit print agent to form a second fiducial on a second, opposite side of the substrate, the second fiducial comprising an inverted version of the shape of the first colour; operate the first light source to back-illuminate the substrate; operate the detector to detect the first and second fiducials; and determine whether the first fiducial is aligned with the second fiducial. A method and a machine-readable medium are also disclosed.

Determining alignment using fiducials

A print apparatus is disclosed. The print apparatus comprises a plurality of printing elements; and a temperature control unit, controllable by processing circuitry, to increase an operating temperature of a first printing element in the plurality of printing elements by a defined amount relative to an operating temperature of a second printing element in the plurality of printing elements. A method and a machine-readable medium are also disclosed.

Increasing temperatures of printing elements

Printing liquid is spat from ai least one printhead nozzle onto a printing medium in a spitting zone when the printhead traverses the spitting zone during printing. The spitting zone is an area of the printing medium located at least partially in a second half of the printing medium in the direction of printhead travel, and wherein a centre point of the spitting zone is located in the second half of the printing medium in the direction of printhead travel.

Printhead and printhead maintenance

A method is described in which image data of an image to be printed is obtained wherein the image data includes data of each colorant to be printed. The image data of each colorant to be printed is analysed to detect areas of the image in which dye-enriched colorant will occur during printing. The image data is modified to compensate for over-saturation due to the dye-enriched colorant in the detected areas and the image is printed based on the modified image data.

Compensating over-saturation due to dye-enriched colorant

A printing apparatus is disclosed. The printing apparatus comprises a printhead and a controller. The printhead is to spit a printing fluid comprising a first mode and a second mode. The first mode corresponds to using a first energy level to spit the printing fluid and the second mode corresponds to using a second energy level to spit the printing fluid. The second energy level comprises a higher energy level than the first energy level. The controller is to determine a decap risk zone associated with the printing fluid, determine in view of the decap risk zone a decap location, and instruct the printhead to spit using the second mode at the decap location.

Spit energy levels

In an example there is provided a printing method comprising receiving first and second image data for first and second images to be printed on a substrate, determining first print data for the first image on the basis of the first image data and a white layer to be printed between the first image and second image, to achieve a nominal color profile for the first image; determining second print data for the second image on the basis of the first image data, second image data, the white layer and one or more properties of the substrate to achieve a nominal color profile for the second image; communicating the print data for the first and second images to a printing device to print the first and second images and white layer on the substrate.

Printing images for variable lighting conditions

A method comprises printing an image using a printhead cartridge including a number of dies, each die comprising a nozzle array, the printing comprising: determining a drop parameter of fluid drops ejected from nozzles of the nozzle array of at least one die; comparing the drop parameter to a threshold value; and determining an image characteristic of an image to be printed; and if the image characteristic meets a defined criterion and if the drop parameter exceeds the threshold value, applying a second print mask for printing the image; and if the image characteristic does not meet the defined criterion or if the drop parameter does not exceed the threshold value, applying a first print mask for printing the image, wherein the second print mask uses less nozzles of the nozzle arrays than the first print mask.

Method of printing and printing apparatus

An example of a color management module is disclosed. The color management module is to generate a mapping from an incoming color space to a printer color space by a color pipeline. In the generation of the mapping, the color pipeline is adjusted so that the mapping of a target color associated with a first composition further includes adding a quantity of a second composition to the mapping of the target color. The second composition comprises a lower visibility than the first composition.

Color pipeline

In an example, there is provided a method and apparatus for generating a print output file, the method comprising receiving at least one image to be printed, determining a printing area corresponding to a region containing the at least one image to be printed and a non-printing area corresponding to a remaining region, providing a spit-on-page dot pattern limited to the non-printing area, and generating the print output file comprising the dot pattern and the at least one image.

A method comprising: soaking a portion of a web in a printing device with printing liquid from a first print head () of the printing device; and wiping at least one nozzle of a second print head () in the printing device with the soaked portion of the web. The method provides a servicing method for print heads in the printing device.

Print head servicing

An example of a printing apparatus comprising a scanning printhead and a controller is disclosed. The scanning printhead comprises a plurality of nozzles to print using a mask comprising a ramp area and non-ramp area. A first subset of nozzles of the plurality of nozzles is assigned to the ramp area and the second subset of nozzles of the plurality of nozzles is assigned to the non-ramp area. The controller is to calculate a number of spits of a nozzle from the second subset of nozzles for a pass. The controller is also to calculate a number of spits of a nozzle from the first subset of nozzles for the pass based on the number of spits of the nozzle from the second subset of nozzles. The controller is further to instruct the nozzle from the first subset of nozzles to eject online an amount of a composition on a service zone based on the number of spits of the first subset of nozzles.

Online spitting

Examples herein provide a method, which includes printing an image and fiducial marks on a first side of a print medium. The fiducial marks include first marks ahead of the image, wherein two of the first marks are end marks at a first distance from respective opposite edges of the print medium, and each first mark has a first length and is located at a second distance from a beginning edge of the image. The fiducial marks also include second marks along a length of the print medium, wherein each second mark is at the first distance from the respective opposite edges, has a second length smaller than the first length, and is at a third distance from another second mark. The method includes scanning the fiducial marks and printing a registered mirrored copy of the image on the second side of the print medium using the scanned fiducial marks.

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Sant Cugat del Valles, Spain

Li Qian