Patent ID: 8585189

Claim:
A method of ejecting liquid drops comprising: providing liquid under pressure sufficient to eject a liquid jet through a nozzle of a liquid chamber; providing input image data; providing a drop formation device; modulating the liquid jet to selectively cause portions of the liquid jet to break off into one or more pairs of drops traveling along a path using the drop formation device associated with the liquid jet, each pair of drops separated on average by a drop pair period, each pair of drops including a first drop and a second drop in response to the input image data; modulating the liquid jet to selectively cause portions of the liquid jet to break off into one or more third drops traveling along the path separated on average by the same drop pair period using the drop formation device, the third drop being larger than the first drop and the second drop in response to the input image data; providing a charging device including: a charge electrode associated with the liquid jet; and a source of varying electrical potential between the charge electrode and the liquid jet, the source of varying electrical potential providing a waveform, the waveform having a period that is equal to the drop pair period, the waveform including a first distinct voltage state and a second distinct voltage state, the charging waveform being independent of the input image data; synchronizing the charging device with the drop formation device to produce a first charge state on the first drop of the drop pairs, to produce a second charge state on the second drop of the drop pairs, and to produce a third charge state on the third drops; providing a drop merging mechanism; causing the first drop and the second drop of the drop pairs to combine with each other to form a fourth drop having a fourth charge state using the drop merging mechanism; and providing a deflection device; causing the third drop to begin traveling along a first trajectory and causing the fourth drop to begin traveling along a second trajectory using the deflection mechanism, the first and second trajectories being different when compared to each other.