Patent ID: 6705696
Filing Date: 2004-03-16
Classification: B41J

Abstract:
A method of driving an inkjet recording head having a pressure chamber filled with a liquid ink, said pressure chamber including an ink supply port for supplying the liquid ink and an ink nozzle for ejecting said ink in the form of at least one ink droplet, and an electro-mechanical transducer disposed such that a pressure wave is generated in said pressure chamber by applying a driving voltage in order to eject the ink droplet via said ink nozzle, said transducer having an inherent vibration period Ta in a longitudinal vibration mode, said method comprising:generating a first driving voltage waveform, said first driving voltage waveform including consecutively a first waveform portion having a first time length t1 for contracting a volume of said pressure chamber and a second waveform portion having a second time length t2 for expanding the volume of said pressure chamber; setting said first and second time lengths t1 and t2 to a length that is equal to or shorter than the inherent vibration period Ta of said electro-mechanical transducer, wherein the inherent vibration period Ta is 5 &mgr;s or less; and changing a voltage of said first waveform portion by an amount that is smaller than a voltage change amount of said second waveform portion.