Abstract: In an example, a printer controller is coupled to a fluid pump, a primer pump, and a pressure sensor of a printer, wherein a flow channel provides a fluid communication between the fluid pump and the printhead for enabling fluid recirculation in the printer. The printer controller: activates the fluid pump; activates the primer pump for a first predefined time interval; and identifies or determines a movement of fluid in the flow channel based on the fluid pressure measured by the pressure sensor.

Abstract: Fluid supply apparatus 104 is disclosed. The fluid supply apparatus 104 comprises a first conduit 106 to supply fluid to a fluid dispense head and a second conduit 108 to receive fluid from the fluid dispense head. The first conduit 106 and second conduit 108 may both supply print fluid to a print head in a printing or servicing configuration. The first conduit 106 and the second conduit 108 are coupled together via a closable third conduit 116. The closable third conduit 116 permits fluid flow between the first conduit 106 and the second conduit 108. The third conduit 116 comprises deformable walls movable towards each other to close the third conduit 116 to the passage of fluid between the first 106 and second conduit 108.

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: A printing device comprises a printing fluid supply; a plurality of printheads connected in parallel to the supply by a first flow path and a second flow path; a first fluid pressure source to create a negative fluid pressure between the supply and the first openings; a second fluid pressure source to create a positive fluid pressure between the supply and the second openings; and a controller. Each printhead comprises a closable first opening connected to the first flow path and a closable second opening connected to the second flow path, and has an associated mechanism to increase a fluid pressure in the printhead. Each first opening is to open in response to operation of the associated mechanism. The controller is to identify a first printhead for which printing fluid in the first printhead is to be recirculated; and operate the mechanism associated with the identified printhead.

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: Example methods for the maintenance of printheads are provided, the printheads comprising a reservoir containing a printing fluid with particles in suspension, and a nozzle plate. Example methods may comprise capping the nozzle plate of the printhead, and rotating the capped printhead. Example maintenance devices for printheads are also provided, comprising a support with a socket to attach a printhead to the support, a drive unit to rotate the support about a rotation axis, and a control unit connected to the drive unit to perform a predetermined rotation cycle.

Abstract: Example methods for the maintenance of printheads are provided, the printheads comprising a reservoir containing a printing fluid with particles in suspension, and a nozzle plate. Example methods may comprise capping the nozzle plate of the printhead, and rotating the capped printhead. Example maintenance devices for printheads are also provided, comprising a support with a socket to attach a printhead to the support, a drive unit to rotate the support about a rotation axis, and a control unit connected to the drive unit to perform a predetermined rotation cycle.

Abstract: In an example, a printer controller is coupled to a fluid pump, a primer pump, and a pressure sensor of a printer, wherein a flow channel provides a fluid communication between the fluid pump and the printhead for enabling fluid recirculation in the printer. The printer controller: activates the fluid pump; activates the primer pump for a first predefined time interval; and identifies or determines a movement of fluid in the flow channel based on the fluid pressure measured by the pressure sensor.

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: Example methods for the maintenance of printheads are provided, the printheads comprising a reservoir containing a printing fluid with particles in suspension, and a nozzle plate. Example methods may comprise capping the nozzle plate of the printhead, and rotating the capped printhead. Example maintenance devices for printheads are also provided, comprising a support with a socket to attach a printhead to the support, a drive unit to rotate the support about a rotation axis, and a control unit connected to the drive unit to perform a predetermined rotation cycle.

Abstract: Fluid supply apparatus 104 is disclosed. The fluid supply apparatus 104 comprises a first conduit 106 lo supply fluid to a fluid dispense head and a second conduit 108 to receive fluid from the fluid dispense head. The first conduit 106 and second conduit 108 may both supply print fluid to a print head in a printing or servicing configuration. The first conduit 106 and the second conduit 108 are coupled together via a closable third conduit 116. The closable third conduit 116 permits fluid flow between the first conduit 106 and the second conduit 108. The third conduit 116 comprises deformable walls movable towards each other to close the third conduit 116 to the passage of fluid between the first 106 and second conduit 108.

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: A printing device comprises a printing fluid supply; a plurality of printheads connected in parallel to the supply by a first flow path and a second flow path; a first fluid pressure source to create a negative fluid pressure between the supply and the first openings; a second fluid pressure source to create a positive fluid pressure between the supply and the second openings; and a controller. Each printhead comprises a closable first opening connected to the first flow path and a closable second opening connected to the second flow path, and has an associated mechanism to increase a fluid pressure in the printhead. Each first opening is to open in response to operation of the associated mechanism. The controller is to identify a first printhead for which printing fluid in the first printhead is to be recirculated; and operate the mechanism associated with the identified printhead.

Abstract: Example methods for the maintenance of printheads are provided, the printheads comprising a reservoir containing a printing fluid with particles in suspension, and a nozzle plate. Example methods may comprise capping the nozzle plate of the printhead, and rotating the capped printhead. Example maintenance devices for printheads are also provided,comprising a support with a socket to attach a printhead to the support, a drive unit to rotate the support about a rotation axis, and a control unit connected to the drive unit to perform a predetermined rotation cycle.