INK JET HEAD

An ink jet head includes a piezoelectric member (5) to drive a pressure chamber (51), an electrode pair (53, 55) to apply a voltage to the piezoelectric member, and a common waveform generation circuit (61) to generate a common waveform. The common waveform alternately includes an element of a first output waveform and an element of a second output waveform at a predetermined period. A switch (7) is connected between a first electrode of the electrode pair and the common waveform generation circuit. A timing controller (62) supplies a control signal to turn the switch on and off at the predetermined period such that the first or second output waveform can be selectively applied to the piezoelectric member to drive the pressure chamber to eject a liquid.