Ink jet printing head utilizing pressure and potential gradients.

摘要

An ink jet printing head comprises a laminar airflow chamber having a front channel through a combined stream of air and ink droplets is discharged toward a writing surface, and a rear channel axially aligned with the front channel connected to a source of liquid. The chamber is further provided with an air intake connected to a pressurized air supply source for directing an airstream to a point between the front and rear channels so that the airstream makes a sharp turn at the entry into the front channel with the result that a sharp pressure gradient is produced in the liquid discharge path. An electrode is provided for establishing a field between the front channel and the liquid's meniscus at the exit end of the rear channel to cause the latter to extend toward the front channel by combined effects of the potential and pressure gradients and to be torn apart into a droplet which is carried by the airstream discharged through the front channel.