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.

A wafer structure is disclosed and includes a chip substrate and a plurality of inkjet chips. The chip substrate is a silicon substrate which is fabricated by a semiconductor process. The plurality of inkjet chips include at least one first inkjet chip and at least one second inkjet chip. The plurality of inkjet chips are directly formed on the chip substrate by the semiconductor process, respectively, and diced into the at least one first inkjet chip and the at least one second inkjet chip, to be implemented for inkjet printing. Each of the first inkjet chip and the second inkjet chip includes a plurality of ink-drop generators produced by the semiconductor process and formed on the chip substrate. Each ink-drop generator includes a barrier layer, an ink-supply chamber and a nozzle. The ink-supply chamber and the nozzle are integrally formed in the barrier layer.

Methods, systems, and devices related to a printer system that includes a first primary ink tank holding a dark-colored ink, a second primary ink tank holding a light-colored ink, a first selector valve configured to change a state, a first secondary ink tank connected to the first primary ink tank via the first selector valve, a second secondary ink tank connected to the first and second primary ink tanks via the first selector valve, a second selector valve connected to the first primary ink tank configured to return the dark-colored ink from the print heads to the first primary ink tank, and a third selector valve connected to the second selector valve and the second primary ink tank configured to either return the light-colored ink from the print heads to the second primary ink tank or to direct the dark-colored ink to the second selector valve.

An inkjet recording device and a method for controlling an inkjet recording device are provided. A heating device that heats the ink to be supplied to a nozzle immediately ahead of the nozzle, a thermometer that detects a temperature of the ink inside the heating device or after heating, a viscometer that detects a viscosity of the ink in a main ink container are provided. The heating device is driven using a detection value of the thermometer to control the temperature of the ink such that the viscosity reaches an ink viscosity which enables normal printing, and when the viscosity of the ink is out of a range which enables printing, the solvent or the replenishment ink is supplied to the main ink container using a detection value of the viscometer such that the viscosity reaches the range which enables normal printing.

Systems and methods for industrial printing, e.g., using drop-on-demand (DOD) inkjet print heads, include, in at least one aspect, a printing device including: a print head including a print engine, including multiple nozzles, and circuitry to selectively eject ink through the multiple nozzles to form an image on a moving substrate, and to purge the ink through the multiple nozzles; and a printhead enclosure having an opening in front of the multiple nozzles to allow the selectively ejected ink to pass through the opening when the selectively ejected ink is ejected toward the moving substrate; wherein the printhead enclosure includes a hole placed away from the multiple nozzles; and wherein the printhead enclosure is configured to direct the ink that is purged through the multiple nozzles along an inside surface of the printhead enclosure to the hole through which the ink flows and exits the printhead enclosure.

Methods, systems, and devices related to a printer system that includes a first primary ink tank holding a dark-colored ink, a second primary ink tank holding a light-colored ink, a first selector valve configured to change a state, a first secondary ink tank connected to the first primary ink tank via the first selector valve, a second secondary ink tank connected to the first and second primary ink tanks via the first selector valve, a second selector valve connected to the first primary ink tank configured to return the dark-colored ink from the print heads to the first primary ink tank, and a third selector valve connected to the second selector valve and the second primary ink tank configured to either return the light-colored ink from the print heads to the second primary ink tank or to direct the dark-colored ink to the second selector valve.

A print apparatus is disclosed. The print apparatus comprises a container-receiving unit for receiving a reusable print agent container; a print agent reservoir for storing print agent to be consumed by the print apparatus during a printing operation; a pump for transferring print agent between a reusable print agent container positioned in the container-receiving unit and the print agent reservoir; and processing circuitry. The processing circuitry is to operate the pump to transfer print agent of a first concentration from the reusable print agent container to the print agent reservoir; and, responsive to determining that a volume of print agent of the first concentration in the reusable print agent container has fallen below a threshold volume, operate the pump to transfer a volume of print agent of a second, lower concentration from the print agent reservoir to the reusable print agent container. A method and a machine-readable medium are also disclosed.

An inkjet printer has a print assembly and a print material feed system comprising a first circulation circuit and a second circulation circuit, the first circulation circuit fluidly coupled between the second circulation circuit and the print assembly.

A print material container comprising a body, a transfer mechanism, an inner connector, and an outer connecter. The transfer mechanism is to move print material in or out of the body. The inner connecter is on a connecting side of the body, and is to couple to a first location of an image forming apparatus to provide print material to the image forming apparatus. The outer connecter is on the connecting side of the body, and is to couple to a second location of the image forming apparatus to collect or receive unutilized print material transferred or received from the image forming apparatus.

Methods, systems, and devices related to a printer system that includes a first primary ink tank holding a dark-colored ink, a second primary ink tank holding a light-colored ink, a first selector valve configured to change a state, a first secondary ink tank connected to the first primary ink tank via the first selector valve, a second secondary ink tank connected to the first and second primary ink tanks via the first selector valve, a second selector valve connected to the first primary ink tank configured to return the dark-colored ink from the print heads to the first primary ink tank, and a third selector valve connected to the second selector valve and the second primary ink tank configured to either return the light-colored ink from the print heads to the second primary ink tank or to direct the dark-colored ink to the second selector valve.