Controlling waveforms to reduce cross-talk between inkjet nozzles

A method of printing, comprising:

• providing a liquid chamber having a plurality of nozzles disposed along a nozzle array direction, the plurality of nozzles including a first group of nozzles and a second group of nozzles, the nozzles of the first group being interleaved with the nozzles of the second group;
• providing liquid under pressure in the liquid chamber, the pressure being sufficient to eject liquid jets through the plurality of nozzles;
• providing a drop-formation device associated with each of the plurality of nozzles;
• providing a first set of drop-formation waveforms and a second set of drop-formation waveforms, wherein the first set of drop-formation waveforms and the second set of drop-formation waveforms each include:
• one or more printing-drop drop-formation waveforms having a waveform period, which, when supplied to a drop-formation device associated with a particular nozzle, modulate the liquid jet ejected from the particular nozzle to selectively cause portions of the liquid jet to break off into a pair of drops traveling along a path, the pair of drops including a small printing drop and a small non-printing drop;
• and
• one or more non-printing-drop drop-formation waveforms, which, when supplied to a drop-formation device associated with a particular nozzle, modulate the liquid jet ejected from the particular nozzle to selectively cause a portion of the liquid jet to break off into a large non-printing drop traveling along the path, the large non-printing drop being larger than the small printing drop and the small non-printing drop, the non-printing-drop drop-formation waveforms having the same waveform period as the printing-drop drop-formation waveforms;
• wherein each of the drop-formation waveforms provides an associated waveform energy when supplied to the corresponding drop-formation device, and wherein the waveform energies associated with the drop-formation waveforms in the second set of drop-formation waveforms is larger than the waveform energies associated with the corresponding drop-formation waveforms in the first set of drop-formation waveforms;
• providing input image data;
• controlling the drop-formation devices associated with each of the plurality of nozzles in response to the provided input image data, wherein the first group of nozzles are controlled with a sequence of drop-formation waveforms selected from the first set of drop-formation waveforms and the second group of nozzles are controlled with a sequence of drop-formation waveforms selected from the second set of drop-formation waveforms;
• providing a phase control means for controlling a phase of the drop-formation waveforms used to control the drop-formation devices associated with the second group of nozzles such that the phase is shifted by a second-group phase shift relative to the drop-formation waveforms used to control the drop-formation devices associated with the first group of nozzles, wherein the second-group phase shift is a fraction of the waveform period;
• providing a charging device including:
• a common charging electrode positioned in proximity to the liquid jets ejected through both the first and second groups of nozzles;
• and
• a charging-electrode waveform source providing a varying electrical potential between the charging electrode and the liquid jets according to a predefined periodic charging-electrode waveform, the charging-electrode waveform including a first portion providing a first electrical potential and a second portion providing a second electrical potential, wherein the charging-electrode waveform has the same waveform period as the drop-formation waveforms;
• synchronizing the drop-formation devices, the phase control means, and the charging device, wherein the waveform energies associated with the drop-formation waveforms in the first and second sets of drop-formation waveforms and the second-group phase shift are selected such that the small printing drops break off from the liquid jets during the first portion of the charging-electrode waveform to provide a first printing-drop charge state, and the small non-printing drops and the large non-printing drops break off from the liquid jets during the second portion of the charging-electrode waveform to provide a second non-printing-drop charge state;
• providing a deflection device which causes the printing drops having the first printing-drop charge state to travel along a different path from the non-printing drops having the second non-printing-drop charge state;
• and
• intercepting the non-printing drops using an ink catcher while allowing the printing drops to travel along a path toward a receiver.