Patent attributes
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 τUP of rise of voltage when the drive voltage is applied and/or the time constant τDN 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)≦τUP≦Ta/(−ln 0.25) (i)Ta/(−ln 0.01)≦τDN≦Ta/(−ln 0.25) (ii)with respect to the period Ta of the ensuing vibration of the drive section, or pulse width T3 of the drive voltage is set at an integral multiple of the period Ta of the ensuing vibration of the drive section.
