Abstract: Electrostatic deflection of portions of a liquid stream is used to generate lengths of liquid (called "slugs" of liquid) for use in jet printing apparatus. The liquid stream is projected along a path alongside a linear or arcuate array of electrodes. When a voltage signal is applied sequentially to each electrode of the array at a rate which corresponds to the velocity of liquid of the stream past the electrodes, a portion of the liquid is deflected out of the path of the stream and towards the array. Either the deflected portion or the undeflected stream is intercepted before it reaches a surface which is to be printed. The slugs of liquid may break up naturally into droplets before the interception of the deflected portion or the undeflected stream, or after the interception has occurred. High resolution printing with high volumes of liquid is possible using this invention.

Abstract: A printing head for generating slugs of liquid comprising: (a) a liquid stream generating section adapted to receive liquid under pressure and having an orifice for producing a coherent, continuous stream of the liquid; (b) an electrode supporting section on which is mounted an electrode, the electrode being positioned adjacent to the trajectory of the liquid stream and extending in the direction of flow of the liquid stream; and (c) a collector section, comprising an impingement region which is inclined towards the axis of the liquid stream when the liquid stream impinges thereon and a run-off region which is inclined away from the axis of the liquid stream at the point where the liquid stream impinges upon the impingement region.