Hewlett-packard Development Company, L.p.

Secundino Vicente Vicente

Li Qian

Xavier Domingo Reguant

Xavier Domingo

Marc Bautista Palacios

Francisco Guerrero Carvajal

Yngvar Rossow Sethne

Tuomo Eljas Kaikkonen

Annarosa Multari

Alfonso Sanchez

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

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.

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.

Printing using fiducial marks

Examples herein provide a method. The method includes printing first color patches at a first location on a first side of a print medium. The method includes generating an international color consortium ('ICC') profile of the first side by characterizing the first color patches using a spectrophotometer. The method includes printing, using the ICC profile of the first side, second color patches at a second location on the first side of the print medium. The method includes printing third color patches on a second side of the print medium, the third patches being a registered mirrored copy of the second patches. The method includes generating an ICC profile of the second side by characterizing the registered second and third patches using the spectrophotometer.

Printing using a spectrophotometer

According to one example, there is provided a method of generating a day/night image on a media. The method comprises obtaining an image to be printed as a front-to-back image, printing the obtained image on a first side of the media, processing the obtained image by flipping the image, applying a degree of edge removal, and applying a degree blur. The method further comprises printing the processed image on a reverse side of the media, such that the first printed image and printed modified image are substantially aligned with one another.

Generating a day/night image

A control system for controlling actuators comprises a central processor, a plurality of actuators, and a plurality of servo systems for controlling the respective actuators. Each servo system is operable, independently of the central processor, to control a controlled parameter (Y) in accordance with a reference value (R). The servo systems and the central processor communicate via a non-deterministic communications system. The central processor and the servo systems provide, to the central processor via the non-deterministic communications system, offset signals representing offsets (R&#x2212;Y) measured by the servo systems between reference R and actual Y values of the controlled parameter. The central processor compares the offsets (R&#x2212;Y) measured by the respective servo systems one with another.

Controlling actuators

In some examples, a method of controlling printing to a print medium includes, while printing an image to a print surface of the print medium, determining deformations of slices of the image caused by deformation of the print medium. The determining includes reading first fiducial marks printed on the print medium, determining a first deformation of a first slice of the slices based on the first fiducial marks, reading second fiducial marks printed on the print medium, and determining a second deformation of a second slice of the slices based on the second fiducial marks.

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Sant Cugat del Valles, Spain

Secundino Vicente Vicente