Ink jet printer having a thermal actuator comprising an external coil spring

An ink jet printer having a series of ink ejection nozzle chambers, each of said nozzle chambers containing:

• an ink ejection port defined in one wall of the chamber for the ejection of ink therefrom;
• a paddle within said chamber, actuated by an actuator for the ejection of ink from said nozzle chamber via said ink ejection port;
• a slot defined in a second wall thereof for the communication with said paddle of an actuator device;
• a thermal actuator activated by means of conductive heating of an electrically conductive material, said actuator comprising:
• a first non-conductive strip of material attached to a substrate at a first end of said strip and adapted to apply a force to a load at a second end of said strip;
• a second conductive material formed along one side of said first strip said second conductive strip including a first wire strip running from substantially said first end to said second end and a second wire strip running from substantially said second end to said first end, said wire strips being joined together at said second end so as to form a circuit, said wire strips being further connected to a controlled power supply at said first end such that activation of said controlled power supply causes heating of said conductive material so as to actuate said thermal actuator thereby applying a force to said load.