Patent ID: 6508411
Filing Date: 2003-01-21
Classification: B41J,F04B

Abstract:
A method of driving a liquid-drop spraying device, comprising the steps of:providing a liquid-drop spraying device comprising a plurality of adjacent liquid-drop discharge units each having a nozzle for discharging liquid, a pressure chamber for pressurizing liquid to be discharged from a respective nozzle, an inlet hole for supplying liquid to said pressure chamber and a piezoelectricelectrostriction element to pressurize and operate said pressure chamber, wherein said inlet holes of each of said liquid-drop discharge units are connected to a common liquid supply path, and wherein a ratio of an aperture of said inlet hole to an aperture of said nozzle is in a range of 0.6 to 1.6 and a ratio of said nozzle aperture to a nozzle thickness is in a range of 0.2 to 4; applying a predetermined voltage signal, beginning from a starting charge voltage, to each said piezoelectricelectrostriction element to charge said piezoelectricelectrostriction element and deform a wall portion of a respective pressure chamber such that liquid supplied to said respective pressure chamber is discharged from said nozzle due to the pressure produced in said respective pressure chamber; holding a final charging voltage applied to said piezoelectricelectrostriction element for a predetermined time; sequentially performing first and second discharging steps with at least two discharge time constants, wherein an initial discharge time constant is larger than a second discharge time constant; and starting said second discharging step at a voltage that is 35 to 70% of a voltage difference between said starting charge voltage and said final charge voltage.