Inkjet nozzle arrangement with rectangular plan nozzle chamber and ink ejection paddle

1. A nozzle arrangement for an inkjet printhead, the nozzle arrangement comprising:

a substrate assembly incorporating an electrical drive circuitry layer and defining an ink inlet channel;

a nozzle chamber structure extending from the substrate assembly and defining a nozzle chamber in fluid communication with the ink inlet channel and an ink ejection port in fluid communication with the nozzle chamber, the nozzle chamber being rectangular in plan;

an anchor extending from the substrate assembly;

a thermal bend actuator extending from the anchor and electrically coupled to the drive circuitry layer; and

a lever arm coupled to the thermal bend actuator, pivotally supported by the substrate assembly and terminating in a paddle within the nozzle chamber, wherein

upon receipt of a driving signal from the drive circuitry layer, the thermal bend actuator bends to induce movement of the paddle and effect ejection of ink in the nozzle chamber through the ink ejection port, and

the paddle has a rectangular profile substantially corresponding to the nozzle chamber.

2. A nozzle arrangement as claimed in claim 1 , wherein the lever arm defines a sealing portion which forms part of an ink sealing wall of the nozzle chamber structure.

3. A nozzle arrangement as claimed in claim 1 , wherein the paddle is interposed between the ink inlet channel ink and the ejection port.

4. A nozzle arrangement as claimed in claim 1 , wherein the nozzle chamber structure further defines a recess positioned about the rim to inhibit ink spread.

5. A nozzle arrangement as claimed in claim 1 , wherein the substrate assembly includes an ink passivation layer positioned on the drive circuitry layer.