摘要 |
<p>A method is disclosed for controlling a multi-nozzle CIJ printhead having a pressure modulator for causing streams of ink emitted from the nozzles to be broken up into individual droplets, and charge electrodes 6 and charge electrode controllers for controllably applying a charge to individual ones of the droplets in each stream. The method involves generating a modulation waveform to operate the pressure modulator to cause droplets to be generated in each stream and operating the charge controllers to supply a charge signal waveform to each charge electrode. The charges applied to the streams of droplets are compared to a reference or threshold value. The number of droplet streams in which the droplet charges exceed the reference or threshold value is determined plural times and an average value for the number is calculated. This step is repeated a number of times and if the average is less than the average previously calculated then the threshold or reference value is reduced.</p> |