The present invention provides a method for driving a piezoelectric ink
jet head that surely suppresses the ensuing vibration of the drive
section while suppressing the flying speed of the ink droplet from
decreasing, by setting the time constant .tau..sub.UP of rise of voltage
when the drive voltage is applied and/or the time constant .tau..sub.DN
of fall of voltage when stopping the application of the drive voltage are
set in ranges that satisfy the relations of the expressions (i) and (ii):
Ta/(-ln 0.01).ltoreq..tau..sub.UP.ltoreq.Ta/(-ln 0.25) (i) Ta/(-ln
0.01).ltoreq..tau..sub.DN.ltoreq.Ta/(-ln 0.25) (ii) with respect to the
period Ta of the ensuing vibration of the drive section, or pulse width
T.sub.3 of the drive voltage is set at an integral multiple of the period
Ta of the ensuing vibration of the drive section.