Abstract: A printer comprising: an inkjet printhead having an ink inlet, an ink outlet and a plurality of nozzles; a priming system for priming the printhead, the priming system comprising: an ink chamber having an outlet port connected to the ink inlet via an upstream ink line; an air pump having a pump outlet communicating with a headspace above the ink in the chamber; a sensor positioned for sensing ink in a downstream ink line connected to the ink outlet, the sensor cooperating with the pump such that the pump is shut off when the sensor senses any ink; and means for minimizing phantom sensing of ink caused by ink bubbles in the downstream ink line, wherein, in a priming configuration, the pump is configured to positively pressurize the headspace until the sensor senses ink.

Abstract: A priming system for priming an inkjet printhead having an ink inlet, an ink outlet and a plurality of nozzles, the priming system comprising: an ink chamber having an outlet port connected to the ink inlet via an upstream ink line; an air pump having a pump outlet communicating with a headspace above the ink in the ink chamber; a sensor positioned for sensing ink in a downstream ink line connected to the ink outlet, the sensor cooperating with the pump such that the pump is shut off when the sensor senses any ink; and means for minimizing phantom sensing of ink caused by ink bubbles in the downstream ink line, wherein, in a priming configuration, the pump is configured to positively pressurize the headspace until the sensor senses ink.

Abstract: A printer comprising: an inkjet printhead having an ink inlet, an ink outlet and an array of nozzles; an ink chamber having an outlet port connected to the ink inlet via an upstream ink conduit; an air pump having a pump outlet communicating with a headspace in the ink chamber, the pump being configured to positively pressurize the headspace during a printhead priming operation; and a downstream ink conduit connected to the ink outlet, the downstream ink conduit communicating with a pump inlet of the pump, wherein the downstream ink conduit includes an expansion chamber for accommodating a volume of ink, thereby inhibiting the ink from reaching the pump inlet.

Abstract: An ink supply system for supplying ink to an inkjet printhead at a predetermined hydrostatic pressure, the ink supply system comprising: a pressure-regulating chamber having an outlet port connected to an ink inlet of the printhead, the chamber comprising a float valve configured for maintaining a predetermined level of ink in the chamber, the level of ink controlling the hydrostatic pressure; and an ink reservoir connected to an inlet port of the pressure-regulating chamber, the ink reservoir being positioned above the predetermined level of ink.

Abstract: A printer comprising: an inkjet printhead having an ink inlet, an ink outlet and a plurality of nozzles; an ink chamber having an outlet port; an upstream ink line providing fluid communication between the outlet port and the ink inlet; a reversible air pump having a pump outlet communicating with a headspace in the ink chamber, the pump being configured to positively pressurize the headspace during a printhead priming operation or negatively pressurize the headspace during a printhead depriming operation; and a downstream ink line connected to the ink outlet, the downstream ink line being in fluid communication with a pump inlet so as to effect cooperative pulling and pushing of ink through the printhead during the priming and depriming operations.

Abstract: A printer comprising: a printhead having an ink inlet and an ink outlet; a pressure-regulating chamber having an outlet port connected to the ink inlet via an upstream ink conduit, the chamber containing ink at a first level below the printhead, wherein a headspace above the first level of ink is open to atmosphere; and a downstream ink conduit connected to the ink outlet and terminating above the first level of ink, the downstream ink conduit being open to atmosphere, wherein the downstream ink conduit comprises a loop section passing below the first level of ink, such that, in a printing configuration, a second level of ink in the loop is equal to the first level of ink in the chamber.