Patent ID: 6460960
Filing Date: 2002-10-08
Classification: B41J

Abstract:
A method for driving an ink jet head in which at least a portion of a wall surface of an ink chamber communicating at one end with a nozzle and at the other end with an ink reservoir is deformed by a piezoelectric actuator to eject ink, comprising:a first driving stage in which a voltage applied to said piezoelectric actuator is lowered from an initial voltage value (VH), thereby driving the actuator to deform in a direction that increases the internal volume of the ink chamber and thus causing a meniscus in the nozzle to deflect toward the inside of the ink chamber; a second driving stage in which the piezoelectric actuator is driven to deform in a direction that reduces the internal volume of the ink chamber, thereby causing the meniscus in the nozzle to deflect toward the outside of the ink chamber and thus ejecting an ink droplet, and wherein: the second driving stage terminates when a main droplet is formed with the meniscus protruding outwardly from the ink chamber through the nozzle, wherein the driving voltage at that time is lower than the initial voltage value (VH); and a third driving stage in which after the second driving stage terminates, the piezoelectric actuator is driven to deform in the direction that increases the internal volume of the ink chamber, thereby causing the meniscus in the nozzle to deflect toward the inside of the ink chamber.