Patent ID: 7494209

Claim:
A printhead module, comprising: a printhead body including one or more pumping chambers, where each pumping chamber includes a receiving end configured to receive a printing liquid from a printing liquid supply and an ejecting end for ejecting the printing liquid from the pumping chamber; a nozzle plate including one or more nozzles formed through the nozzle plate, where a nozzle is in fluid communication with each pumping chamber and receives printing liquid from the ejecting end of the pumping chamber for ejection from the nozzle and where the nozzle plate includes one or more regions of reduced thickness and where an inner surface of each such region forms an inner surface of each of the one or more pumping chambers; and one or more piezoelectric actuators connected to the nozzle plate, where a piezoelectric actuator is positioned over each pumping chamber and includes a piezoelectric material configured to deflect and pressurize the pumping chamber, so as to eject printing liquid from a corresponding nozzle that is in fluid communication with the ejecting end of the pumping chamber and where the piezoelectric material is positioned between a first and a second electrode and the first electrode is positioned between the piezoelectric material and an outer surface of one of the regions of reduced thickness of the nozzle plate.