Patent ID: 7524031

Claim:
A printhead for an inkjet printer, the printhead having a plurality of nozzle arrangements arranged in staggered rows, each nozzle arrangement comprising: a substrate assembly defining an ink inlet channel; a static nozzle chamber wall extending from the substrate assembly and surrounding the ink inlet channel; a roof structure defining a movable nozzle chamber wall surrounding the static nozzle chamber wall and which, together with the static nozzle chamber wall, defines a nozzle chamber in fluid communication with the ink inlet channel, the roof structure further defining an ink ejection port in fluid communication with the nozzle chamber; and a thermal actuator comprising an anchor located outside the static nozzle chamber wall and a plurality of actuator arms extending from the anchor to the roof structure, the thermal actuator being configured so that, upon actuation, the roof structure moves responsive to differential expansion of the arms and ink within the nozzle chamber is ejected from the ink ejection port.