Patent ID: 7708382
Filing Date: 2010-05-04
Classification: B41J

Abstract:
1. A nozzle arrangement for an inkjet printhead, the nozzle arrangement comprising a wafer substrate that defines an inlet channel and incorporates CMOS layers to generate electrical drive signals; a nozzle chamber wall and a roof wall positioned on the wafer substrate to define a nozzle chamber in fluid communication with the inlet channel, the roof wall defining an ink ejection port in fluid communication with the nozzle chamber; a paddle positioned in the nozzle chamber and reciprocally displaceable to eject ink from the ejection port; and an actuating arm extending through the nozzle chamber wall and connected to the paddle, the actuating arm comprising an actuating portion having a pair of actuating members, one of the actuating members defining a heating circuit such that, on receipt of an electrical signal to the exclusion of the other actuating member, the actuating arm is displaced in one direction as a result of differential thermal expansion, the actuating arm being of a resiliently flexible material such that, when the electrical signal is cut off, the actuating arm is displaced in an opposite direction, wherein a passivation layer is positioned on the substrate to protect the CMOS layers from the ink.