Patent ID: 7025436

Claim:
A method of detecting a blockage within an inkjet nozzle, said inkjet nozzle comprising: an ink chamber; an opening defined in a roof of said ink chamber; an actuating arm movable between a rest position and an operating position, said movement causing ejection of an ink droplet through said opening; and a movement sensor associated with the actuating arm, said movement sensor being activated by movement of the actuating arm to a predetermined position beyond said operating position, the method comprising the steps of: (a) passing at least one blockage-detecting current pulse having a predetermined duration t p through the actuating arm; (b) detecting for movement of the actuating arm to said predetermined position; and (c) comparing the detected movement with the movement in an unblocked condition, wherein movement of the actuating arm in a blocked condition is less than movement of the actuating arm in an unblocked condition.