Non-resonant and decoupled droplet generator

Abstract

A droplet generator and ink jet printhead assembly employing the droplet generator are disclosed. The droplet generator can operate with a wide range of fluids over a wide range of conditions, is easily serviced, and can be easily integrated into a machine such as a Three Dimensional Printing machine. The assembly includes a nozzle having an orifice, a liquid reservoir or supply for containing a liquid to be emitted from the nozzle and a non-resonant elastically deformable fluid conduit for conveying the liquid from the liquid reservoir to the nozzle. A transducer is disposed in abutting relation with the fluid conduit a predetermined distance from the nozzle. The transducer is energized by a suitable electrical signal, such as a sinusoidal signal. The transducer causes compression of the conduit and provides a wave which propagates along the fluid conduit and fluid contained therein toward the nozzle and orifice. This wave acts to perturb the stream formed at the orifice and to initiate the break-up of the stream into droplets. The utilization of an elastically deformable non-resonant conduit between the transducer and the nozzle mechanically decouples the nozzle from the remainder of the printhead assembly and provides filtering of undesired frequencies which might otherwise be imparted to the fluid and the nozzle.