METHOD OF MULTI-TONE PRINTING

摘要

Method of Multi-Tone Printing. A method of multi-tone printing employs a drop-on-demand printing apparatus for depositing ink droplets on printing element areas of a substrate which is movable relatively to said apparatus. The droplets are deposited from an array of channels on a substrate which is movable relatively to the channels. The channels length and nozzle location and dimensions afford each channel with a high longitudinal resonant frequency and electrically actuable means supply energy pulses to selected channels at or near the resonant frequency of the channels to deposit from each selected channel in the corresponding printing element area of the substrate a number of drops equal to the number of pulses applied thereto, the number of pulses applied being dependent on the tone of printing required. Single channel and colour versions of the invention are also disclosed.