Patent ID: 7997709
Filing Date: 2011-08-16
Classification: B41J

Abstract:
1. A drop on demand ink jet print head comprising: a nozzle plate defining a wall of a chamber; a nozzle opening through said nozzle plate from which liquid droplets can selectively be ejected from the chamber; a plurality of liquid passages into said chamber adapted to continuously move the liquid into the chamber to a stagnation point adjacent to the nozzle opening where the liquid located at the stagnation point comes substantially to rest, the stagnation point being on a stagnation streamline in the chamber which divides liquid flow in half and is directed towards the nozzle opening; a plurality of liquid passages out of said chamber adapted to continuously move the liquid from the stagnation point such that vector sum of liquid flow derived forces within the liquid channels is neutral; and at least one actuator associated with said chamber for selectively increasing pressure of the liquid at the stagnation point to thereby eject a liquid drop from said nozzle opening.