Ink ejection nozzle arrangement
A printhead is provided for an inkjet printer. The printhead includes a wafer assembly defining a plurality of spaced apart groups of ink supply channels and a plurality of groups of ink ejection nozzle arrangements in fluid communication with respective ink supply channel groups. Each ink ejection nozzle arrangement includes a nozzle chamber structure mounted to the wafer assembly. Each ink ejection nozzle arrangement also defines a nozzle chamber for receiving ink from an ink supply channel and a nozzle rim through which ink in the nozzle chamber can be ejected. An anchor extends from the wafer assembly in a location external to the nozzle chamber. An elongate thermal actuator mechanism extends from the anchor and into the nozzle chamber.
1. An ink ejection nozzle arrangement for an inkjet printhead, the ink ejection nozzle arrangement comprising:
a nozzle chamber structure defining a nozzle chamber, the nozzle chamber having a nozzle defined in a roof of the nozzle chamber;
an anchor extending from the wafer assembly in a location;
an elongate arm attached to a post positioned external to the nozzle chamber, the elongate arm extending from the post and into the nozzle chamber, the elongate arm terminating in a free end within the nozzle chamber; and
a pair of layers of conductive material located on either side of the elongate arm, one of the layers being connected to a current supply so that, upon receipt of the current supply, differential thermal expansion between the pair of layers cause the free end of the elongate arm to deflect, thereby ejecting ink in the nozzle chamber through the nozzle.
2. An ink ejection nozzle arrangement as claimed in claim 1 , wherein the layers of conductive material are located proximal to the post.
3. An ink ejection nozzle arrangement as claimed in claim 2 , wherein the layers of conductive material abut the post.
4. An ink ejection nozzle arrangement as claimed in claim 2 , wherein the layer connected to the current supply has a thinned portion near the post.
5. An ink ejection nozzle arrangement as claimed in claim 1 , wherein the layers of conductive material are formed from Titanium Nitrate.
6. An ink ejection nozzle arrangement as claimed in claim 1 , further comprising a recess formed substantially around the roof for capturing ink flowing over the roof.