Method and apparatus for drop-on-demand ink jet printing

摘要

A drop-on demand ink jet printer and a method of ink jet printing are disclosed which produce drops whose diameter have a ratio to the internal diameter of their print nozzles of 1:2 instead of the standard ratio of 2:1. This change in the basic ratio of drop diameter to print nozzle diameter is a result of the motion imparted to the print liquid by the actuation of the print nozzle. The print nozzle is cocked, released, and abruptly stopped to impart forward momentum to the print liquid near the orifice of the print nozzle. This momentum urges the liquid to be expelled from the print nozzle. Cutting the orifice of the print nozzle at an oblique angle to the run of the print nozzle creates a leading edge on the print nozzle which increases control of drop placement. The leading edge encourages formation of a single umbilicus of expelled print liquid from which a drop will be severed.