Hewlett-packard Development Company, L.p.

David Butinya Teixido

Albert Crespi Serrano

Miquel Boleda Busquets

Jorge Castano Aspas

Tuomo Eljas Kaikkonen

Marta Coma Vives

Dorkaitz Alain Vazquez Fernandez

Mauricio Seras Franzoso

Josep Ortiz Mompel

Jorge Millan Lafuente

According to an example, a method to determine a printing fluid pressure in a printing fluid delivery system comprises: determining that a pressure difference measured by a fluid pressure sensor of the printing fluid delivery system is outside a dynamic range of the pressure sensor, controlling a fluid supply system of the printing fluid delivery system to increase a fluid pressure to an augmented fluid pressure in which the pressure difference is within the dynamic range of the pressure sensor, determining a fluid pressure value on the fluid pressure sensor, and calculating the printing fluid pressure as a function of the pressure difference and the augmented fluid pressure.

Printing fluid pressure determination

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

Certain examples relate to controlling recirculation processes in a printing apparatus. An example printing material cartridge includes a reservoir storing printing material to supply a printing apparatus; memory; and instructions for controlling a recirculation process in the printing apparatus, the instructions stored in the memory, the recirculation process to cause the printing material to move between the reservoir and a second printing material cartridge, the second printing material cartridge separately replaceable from the printing material cartridge in the printing apparatus.

Printer recirculation control

An example printing fluid circulation system includes a first circuit to circulate a printing fluid through a printhead in a first direction and a second circuit to circulate the printing fluid through the printhead in a second direction opposite to the first direction. The first circuit is activated during a first mode to circulate the printing fluid from a first reservoir to a second reservoir. The second circuit is activated during a second mode different from the first mode to circulate the printing fluid from the first reservoir to the second reservoir.

Printing fluid circulation

Certain examples relate to mixing and/or supply cartridges for printing apparatus. One example implementation includes a reservoir to receive printing material from a printing apparatus and to return the received printing material to the printing apparatus. A storage medium stores a reservoir printing material level parameter indicative of the amount of printing material in the reservoir; a recirculation cycle counter indicative of the number of recirculation events experienced by the cartridge; a maximum recirculation cycle parameter indicative of the maximum number of recirculation events that may be experienced by the cartridge.

Supply and mixing cartridges

A printing device and method is described comprising: selectively generating a negative fluid pressure between one of one or more printing fluid supplies and a first one of first and second ports of a printhead; selectively generating a positive fluid pressure between one of said printing fluid supplies and a second one of the first and second ports of the printhead; and providing a first pulsed signal to a first priming pump associated with a first one of the first and second ports, wherein the first one of said first and second ports of the printhead is opened under the control of said first priming pump, such that printing fluid within the printhead exits the printhead through the first one of the first and second ports.

Printing fluid recirculation

An example printing material cartridge includes a reservoir storing printing material to supply a printing apparatus and a storage medium storing process instructions for controlling the recirculation process in the printing apparatus.

An example printing fluid circulation circuit for a printing system comprises a first circuit port to supply printing fluid to, or receive printing fluid from, a first fluid port of a printhead and a second circuit port to supply printing fluid to, or receive printing fluid from, a second fluid port of a printhead. The printing fluid circulation circuit is to operate in a first mode to concurrently supply printing fluid from the first reservoir to the first circuit port and from the second circuit port to a second reservoir, and in a second mode to concurrently supply printing fluid from the first reservoir to the second circuit port and from the first circuit port to the second reservoir.

Growing community of inventors

Sant Cugat del Valles, Spain

David Butinya Teixido