Patent ID: 7611232

Claim:
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 thickness so as to have a resistance value 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, is not greater than 50 ns.