Patent ID: 7661794

Claim:
A method for driving a droplet discharge head provided with a nozzle, a diaphragm constituting a bottom of a discharge chamber which is communicated with the nozzle and which stores droplets to be discharged, an electrode facing the diaphragm with a gap therebetween, while a voltage is applied between the diaphragm and the electrode, and an insulating film which is disposed on a surface of the diaphragm, the surface facing the electrode, or on a surface of the electrode, the surface facing the diaphragm, and which has been converted to an electret, the diaphragm and the electrode being detachably in contact with each other with the insulating film therebetween by an attraction force generated by an electric field based on the electret, the method characterized by comprising the step of applying a pulsed voltage between the diaphragm and the electrode in such a way as to cancel the electric field based on the electret, the pulse width of the pulsed voltage being adjusted in such a way as to allow the timing of falling of the pulsed voltage to agree with the time when the diaphragm detached from the electrode reaches a point closest to the electrode by the vibration of the diaphragm itself.