VOLTAGE MODULATED DROP-ON-DEMAND INK JET

摘要

A drop-on-demand ink jet printer in which the print head includes a cavity having a nozzle portion at one end and a transducer mounted to contract a wall portion of the cavity when energized by a suitable voltage drive pulse. The drive pulses are produced at a predetermined rate but at a selectively controlled amplitude in response to the print data. In cases where no drop is required to print the data, the drive pulse is at a lower amplitude than the threshold voltage level, and for the first drop to be formed following a time at which no drop was formed, the amplitude of the drive pulse is greater than the threshold voltage level, At steady state operation of producing drops in sequence, the amplitude of the drive pulses equals the threshold voltage level.