Patent ID: 7393072

Claim:
A method of driving an ink-jet printhead, the ink-jet printhead having a pressure chamber to be filled with ink, a piezoelectric actuator for varying a volume of the pressure chamber, and a nozzle, through which an ink droplet is ejected, connected to the pressure chamber, the method comprising: applying a driving pulse to the piezoelectric actuator to change the volume of the pressure chamber, thereby ejecting the ink droplet through the nozzle due to a change in pressure in the pressure chamber caused by the change in volume of the pressure chamber; changing a volume of the ink droplet ejected through the nozzle by maintaining a rising time of the driving pulse constant and adjusting a duration time of a maximum voltage of the driving pulse; and terminating the duration time of the maximum voltage of the driving pulse before a maximum displacement of the piezoelectric actuator is reached.