Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present disclosure refers to a method of monitoring a fluid supply system, the system including a collapsible fluid reservoir to contain a supply of fluid and an outer container to enclose the collapsible fluid reservoir and to receive pressurized gas that pressurizes the supply of fluid, the method comprising a controller to: control a gas pressure pump to feed the fluid to or from the fluid reservoir, the gas pressure pump operating in pressurization cycles; monitor a parameter of the pressurization cycles; and determine a fill state of the fluid reservoir as a function of the monitored parameter.

Abstract: According to an example, a recirculation device having a fluid interconnect assembly comprises an open state and a closed state. The fluid interconnect assembly may comprise an elastic element, a first hollow element, a second hollow element, and a seal movable along the fluid interconnect assembly. The first hollow element and the second hollow element comprise an opening, wherein the hollows element are fluidly connected. In the open state of the device, the first hollow element opening and the second hollow element opening protrude from the seal so that the openings are unsealed. In the closed state of the device, the seal seals the first hollow element opening and the second hollow element opening, being the seal biased towards the closed state by the elastic element.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A device includes a fluid channel connecting a pair of ports and an attachment feature to attach the device at a dummy cartridge; wherein the pair of ports is dimensioned to mate with fluid feed ports of a printer when the device is attached to the dummy cartridge and the dummy cartridge is inserted in the printer.

Abstract: 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.

Abstract: 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.

Abstract: A primer apparatus for a print head structure of an inkjet printer, in which the primer apparatus comprises a pump to supply a flow of air to the print head structure, an outlet valve and a control valve in fluid communication with and disposed between the pump and the outlet valve, the outlet valve comprising a venting structure to reduce the pressure of a flow of air supplied to the print head structure when the control valve is open.

Abstract: 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.

Abstract: 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.

Abstract: A dummy cartridge includes a body having an external shape dimensioned to be received in a cartridge pocket, and a handle integrated into the body, with cavities provided in the body on two opposite sides of the handle; wherein the cavities are dimensioned to allow insertion of a human thumb and/or finger on the two opposite sides of the handle for gripping the handle.

Abstract: 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.

Abstract: 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.

Abstract: Certain examples relate to controlling recirculation processes in a printing apparatus. One example implementation includes a printing material cartridge comprising 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.

Abstract: A differential pressure sensor is used for measuring or identifying a pressure difference, for example to determine a movement or speed of fluid in a fluid conduit or printer re-circulation conduit. The differential pressure sensor determines the difference between an air pressure and a fluid pressure, wherein the fluid is moving in a flow channel. The flow channel includes a surface conveying a fluid between a first port and second port. An opening in the surface of the flow channel provides a fluid communication between the differential pressure sensor and fluid. Moreover, the sensor is arranged in air communication with the pressure box, such as to allow the differential pressure sensor to identify the pressure difference between the air pressure in the pressure box and the fluid pressure in the flow channel.

Abstract: 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.