Hewlett-packard Development Company, L.p.

Dorkaitz Alain Vazquez Fernandez

Josep Ortiz Mompel

Mauricio Seras Franzoso

David Butinya Teixido

Ana Oropesa Fisica

Alvin Zheng-Hui Yu

Antonio Gracia Verdugo

Miquel Boleda Busquets

Lluis Abello Rosello

Albert Crespi Serrano

Alberto Borrego Lebrato

Gianni Cessel

Marcos Casaldaliga Albisu

Carles Carmona Calpe

Joan-Albert Miravet Jimenez

Maria Dinares Argemi

Maurizio Bordone

Jordina Torrents Barrena

Ricard Silvestre

Ryan Suelzle

Ma Pilar Velazquez Gomez

Pablo Carmelo Mena Rodriguez

Jaume Verges Llahi

Example implementations provide a controller to determine a printing fluid abnormality associated with an ink supply channel of a printer; the controller comprising: an input to receive a signal output by a pressure sensor; the signal being indicative of ink pressure associated with the ink supply channel, and a monitor to determine from a characteristic of the signal the presence of an abnormality in the printing fluid.

Monitoring printing fluids

According to an example, a printhead storage device comprises a printhead pocket to receive a printhead, a receptacle with an interior chamber wherein printing fluid is provided, and a fluid interconnect device comprising a fluid path with the interior chamber. Upon insertion of a printhead to the pocket, the fluid interconnect device is connected to the printhead, thereby providing a fluid connection between the printhead and the interior chamber and wherein the printhead is not operable when inserted in the printhead pocket.

Air ingestion prevention

A printing fluid delivery system comprising a fluid pump having an inlet and an outlet, a valve connected to the outlet of the fluid pump, and a controller to close the valve while the fluid pump is driven to increase the pressure at the outlet of the fluid pump based on a service condition and to open the valve based on a predefined relief condition to relieve the pressure at the outlet of the fluid pump.

Fluid delivery system with pump servicing features

A print apparatus is disclosed. The print apparatus comprises a print fluid application unit having a plurality of nozzles through which print fluid is to be deposited onto a printable medium during a printing operation. The print apparatus also comprises a nozzle cleaning surface to engage nozzles during a nozzle cleaning operation. The print apparatus also comprises a scanning unit and a controller. The controller is to control the print fluid application unit to deposit print fluid from nozzles of the plurality of nozzles according to an intended pattern onto the nozzle cleaning surface; control the scanning unit to scan the pattern formed on the nozzle cleaning surface; and responsive to determining, based on the scan, that print fluid from a nozzle of the plurality of nozzles has not been deposited according to the intended pattern, generate an instruction signal regarding maintenance of the print fluid application unit. A method and a machine-readable medium are also disclosed.

Print apparatus maintenance

Examples relate to a method to recirculate print agent in a printing system. The method comprises detecting a recirculation device comprising a check valve and detecting a printhead connected in parallel to the detected recirculation device. The method further comprises selecting a printhead circulation mode to circulate print agent through the detected printhead and selecting a recirculation device circulation mode to circulate print agent through the detected recirculation device.

Recirculation devices with check valve

Examples in accordance with the present disclosure are directed to a method including generating a negative fluid pressure between a fluid supply and a first port of a fluidic ejection device, and generating a positive fluid pressure between the fluid supply and a second port of the fluidic ejection device. The method further includes selectively activating a first priming pump connected to the first port in response to an indication that the first port is transitioning from an open state to a closed state, wherein the selective activation of the first priming pump causes the first port to remain in the open state and causes fluid within the fluidic ejection device to exit through the first port and to recirculate along a fluid flow path.

Recirculation of fluid within a fluidic ejection device

Aspects of the disclosure provide an electronic device comprising a controller. The controller to determine a volume of print fluid in a first tank of the electronic device, monitor current printing conditions of the electronic device disposing print fluid on a substrate, determine, based on the volume of print fluid and the current printing conditions, whether an adverse printing condition exists, responsive to the volume of print fluid being less than a threshold and the adverse printing condition not existing, control a pump to refill the first tank from a second tank at a flow rate determined at least partially according to the determined volume, and responsive to the volume of print fluid being less than the threshold and the adverse printing condition existing, control the pump to refill the first tank from the second tank at a default flow rate determined independent of the determined volume.

Print fluids refills

Growing community of inventors

Sant Cugat del Valles, Spain

Dorkaitz Alain Vazquez Fernandez