Abstract: The invention relates to a droplet deposition apparatus comprising an actuator (100) having a plurality of spaced piezoelectric walls defining channels, said walls having opposed sides; said opposed sides being provided with electrodes being adapted to receive electric signals to deform said walls to cause liquid in said channels to be ejected therefrom; said signals having wave forms; and a control unit (130) for defining the wave forms of said electric signals; wherein the control unit comprises means (500, 514) for providing an individually adapted signal slope of the wave form to selected electrodes (E) so as to compensate for individual channel deviations.

Abstract: The invention relates to a droplet deposition apparatus including an ink actuator (100) for ejecting ink droplets; a control unit (130) for controlling droplet formation; and power supply means for supplying a drive voltage to the control unit (130); the drive voltage having a voltage amplitude (V100); the control unit (130) having a plurality of drive signal sources (320) for defining the wave forms of said electric signals; means (470) for detecting at least one performance affecting value; and means (490) for generating an amplitude control signal in response to the performance affecting value; and wherein the power supply means (330) comprises means (350) for adjusting the amplitude of the drive voltage in response to the amplitude control signal; said power supply means being separated from said control unit.