Multi-nozzle ink jet head

A multi-nozzle ink jet head which is manufactured by a thin film formation technique and has a plurality of nozzles, the multi-nozzle ink jet head comprising:

• a head substrate in which the plurality of nozzles and a plurality of pressure chambers are formed;
• a diaphragm that comprises a common electrode layer and a rigid layer and covers each of the plurality of pressure chambers;
• a plurality of piezoelectric elements provided on the diaphragm in correspondence with the pressure chambers;
• and
• a plurality of individual electrodes provided on the piezoelectric elements in correspondence with the piezoelectric elements,
• wherein the common electrode layer has a minimum thickness of thicknesses of the common electrode layer selected from a range such that a lag in a rise time of a driving waveform when driving all of the piezoelectric elements relative to a rise time of a driving waveform when driving a single one of the piezoelectric elements results in a positional shift of not more than half a dot of a recorded dot formed by a minimum ink amount flying.