Patent ID: 7918540

Claim:
An integrated ink jet printhead chip comprising: a plurality of ink ejection nozzles each including a thermo-mechanical ink ejection actuator formed in a substrate common with the nozzles, each actuator having first and second arms cantilevered at the substrate, each first arm being heated upon application of heating pulses so as to thermally expand relative to the respective second arm causing cantilevered bending of the respective actuator and thereby ejection of ink from the respective nozzle; at least one integrated temperature sensor formed in a substrate common with the nozzles for monitoring the nozzle temperature and outputting a temperature signal representing the monitored nozzle temperature; and, a heating arrangement for applying the heating pulses to the first arms of the actuators, the heating arrangement being arranged to apply heating pulses insufficient to cause ink ejection but sufficient to cause ink warming when the temperature signal represents that the monitored nozzle temperature is below a predetermined threshold until the temperature signal represents that the monitored nozzle temperature is at or above an operational temperature of the printhead at which ink ejection for printing on print media is performed.