APPARATUS AND METHOD FOR SWITCHING DROP SIZE IN INK-JET PRINTING

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and a method for modulating a size of droplets as necessary by using one transducer driving waveform for driving an ink jet. SOLUTION: The driving waveform 100 includes at least a first part 110 and a second part 120 each of which excites a different modal resonance of ink in an ink-jet orifice to generate ink droplets having different sizes. A control signal is applied to the driving waveform to actuate a selected part of the waveform to jet ink droplets of a desired size. The apparatus and method improve a resolution in gray scale printing by identifying an inputted request and placing a combination of small droplets and large droplets in a normal blue noise halftone screen represented as a threshold array so that throughput and image quality targets are met while a jetting robustness risk is reduced.