Patent ID: 6883899
Filing Date: 2005-04-26
Classification: B41J

Abstract:
1. A droplet generator for a continuous stream ink jet print head, comprising: a) an elongate cavity for containing ink; b) nozzle orifices in a wall of said cavity for passing the ink from the cavity to form jets, said nozzle orifices extending along a length of said cavity; and c) actuator means disposed so as to address a face of said cavity opposite said wall to vibrate the ink in the cavity such that each said jet breaks up into ink droplets at substantially a same predetermined distance from said wall, said actuator means comprising a plurality of constituent sub-actuators each capable of independent vibration, each said sub-actuator having an ink addressing face by which it addresses the ink in said cavity, said ink addressing faces being separated by gaps containing ink interfaces, a combined coverage of said face of the cavity by said ink addressing faces of said sub-actuators being such that the break up of the jets is achieved without resonance of said cavity in its dimension from said wall to said cavity face, said sub-actuators being driven in synchronism so that they behave collectively as a single piston-like actuator having an effective ink addressing face comprised as a combination of said ink addressing faces of said sub-actuators.