Hewlett-packard Development Company, L.p.

Andrei Alexandru Dafinoiu

Antonio Gracia Verdugo

Andreu Vinets Alonso

Josep Maria Bel Calavia

Li Qian

David Toussaint

Joan Albert Jorba Closa

Chandrasekhar Nadimpalli

Oscar Martinez Bailac

Marc Gené Alujas

Examples relate to a computer implemented method comprising, based on a vulnerable nozzle map indicating one or more operational nozzles of a printhead identified as meeting a failure likelihood criterion, during a print job, and between successive print passes of the printhead, checking operation of the one or more operational nozzles indicated on the vulnerable nozzle map.

Printhead monitoring

In example implementations, a method, a device, and a program are provided. The method includes detecting a power increase movement of a printer carriage. A location of the printer carriage is detected at a time of the detected power increase. Based on the detected location of the printer carriage, determine whether the print medium is damaged. The device includes a power monitor to detect a power increase during movement of a printer carriage. A locator detects a location of the printer carriage at the time of the detected power increase. A damage determiner determines, based on the detected location of the printer carriage, whether the print medium is damaged. The program detects a power increase during movement of a printer carriage. Location of printer carriage is detected at time of detected power increase. Based on detected location of the printer carriage, it is determined whether the print medium is damaged.

Printing error detection

Example implementations relate to a method to manage printhead operational life; the method comprising firing at least one nozzle of a printhead according to an associated firing parameter to produce a respective drop of print liquid, measuring a parameter associated with the drop of print liquid, and adjusting the firing parameter in response to the measuring to reduce the measured parameter associated with the drop of print liquid on a subsequent firing while maintaining the firing parameter at or above a predetermined parameter limit to maintain print image quality.

Printers and controllers

In an example, a printing apparatus includes a controller, wherein the controller may be to compare a historic usage of a first printhead nozzle with a historic usage of a second printhead nozzle which is located on a same printhead as the first nozzle. The controller may be to determine that the historic usage of the first nozzle is higher than the historic usage of the second nozzle, and in response identify a currently operational third printhead nozzle, for which the second nozzle is able to compensate; and turn off the third nozzle, and operate the second nozzle at a higher firing frequency to compensate for the third nozzle.

Printhead nozzle usage

In some examples, a system detects an error in an printing device, and selects a combination of a medium advance error correction process to address a medium advance error and a faulty nozzle correction process to address a faulty nozzle, where the selecting of the combination is from a plurality of different combinations of the medium advance error correction process and the faulty nozzle correction process, and the selecting is based on a criterion relating to an interaction between the medium advance error and faulty nozzle correction processes.

Selections of correction processes for printing devices

There is disclosed a device, method and program, wherein the method comprises detecting a power increase, during which power usage increases by at least a threshold amount over an expected power usage during movement of a printer carriage over a print medium along a scan axis. The increase method further comprises detecting a location of the printer carriage at a time of the detected power usage increase and determining, based on the detected location of the printer carriage, whether the print medium is damaged.

A controller for a printing device includes print mode controller to determine whether a first or second print mode is to be used for a print job, and temperature controller to control a printhead temperature at least one of prior to and during printing the print job, the temperature controller to activate a printhead heater to cause the printhead temperature to be raised to a first temperature if the print mode controller determines that the first print mode is to be used, and the temperature controller to activate the printhead heater to cause the printhead temperature to be raised to a second temperature if the print mode controller determines that the second print mode is to be used, the second temperature different from the first temperature.

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Sant Cugat del Valles, Spain

Andrei Alexandru Dafinoiu