Distortion reduction in ink jet system printer

Claim 1

In an ink jet system printer of the charge amplitude controlling type for recording characters in a dot matrix pattern by a sequence of charged ink drops, means compensating for the effects of charges on previous ink drops in a sequence on the current charged drops, comprising: a read only memory (ROM) storing digital character generation output formats; means controlling said ROM to output a selected character format; a character generator responsive to said digital character format output from said ROM to produce a step waveform character signal; dot matrix determining means controlling said character generator to correlate said step waveform character signal to said dot matrix pattern; storage means receiving said step waveform character pattern and retaining a predetermined significant number of preceding steps from said waveform for each given current step therein; proportioning means transmitting selectively attenuated magnitudes of said significant steps from said storage means; an adder receiving and summing said attenuated magnitudes to provide a correction signal for a current step in said waveform as a function of said significant number of preceding steps; and means synchronously adding said correction signal to its corresponding step in said stepped character signal to provide a stepped character output signal compensated for the effects of a predetermined significant number of preceding ink drops for each charged ink drop generated.