Drop placement error reduction in electrostatic printer

Abstract

A group timing delay device is provided to shift the timing of drop formation waveforms supplied to drop formation devices of nozzles of one of first and second groups so that print drops formed from nozzles of the first and second groups are not aligned relative to each other along a nozzle array direction. A charging device includes a common charge electrode associated with liquid jets formed from the nozzles of the first and second group and a source of varying electrical potential between the charge electrode and liquid jets. The source of varying electrical potential provides a charging waveform that is independent of print and non-print drop patterns. The charging device is synchronized with the drop formation device and the group timing delay device to produce a print drop charge state on print drops and a non-print drop charge state on non-print drops.