Patent ID: 7591522

Claim:
A method of controlling the quality of an image printed by a printhead having nozzles which discharge ink by application of a firing pulse to respective actuators, the actuators being connected in groups to a power source which applies said firing pulses, said method comprising the steps of: sensing the temperature of the printhead to determine the temperature of the ink, comparing the sensed temperature to values in a pulse duration table to determine a firing pulse duration which will ensure the quality of the printed image; and, applying firing pulses having said determined firing pulse duration to each group of the actuators in turn to discharge ink from the nozzles in each group so as to print an image of said ensured quality, the firing pulses being applied to the subsequent groups so that the fired nozzles are physically separated in the printhead as far as possible from the nozzles fired in the immediately prior group and the immediately subsequent group.