Patent ID: 7896456

Claim:
A method for driving a liquid ejector that comprises (A) a substrate formed by arranging a plurality of liquid droplet ejecting portions each having a pressurizing chamber to be filled with a liquid and a nozzle communicating with the pressurizing chamber for ejecting the liquid from the pressurizing chamber as a liquid droplet in a plane direction; and (B) a plate-shaped piezoelectric actuator laminated on the substrate including at least one piezoelectric ceramic layer having a size covering a plurality of a pressurizing chambers of the substrate, while the piezoelectric actuator is divided into a plurality of piezoelectric deformation regions arranged correspondingly to the respective pressurizing chambers and individually deflected in a thickness direction by individual voltage application and a restricted region surrounding the piezoelectric deformation regions, characterized that: a driving voltage waveform including a first voltage and a second voltage equivalent to the first voltage and opposite in polarity thereto is applied to an arbitrary piezoelectric deformation region of the piezoelectric actuator of the liquid ejector, for deflecting the piezoelectric deformation region in one thickness direction and the opposite direction each and varying a volume of the pressurizing chamber of the corresponding liquid droplet ejecting portion to eject a liquid droplet through the nozzle communicating with the pressurizing chamber.