Patent ID: 8628169

Claim:
A method of cleaning a print head assembly comprising a print head and a cover, wherein the print head comprises: an array of nozzles for ejecting streams of ink; a nozzle face containing nozzle orifices through which the streams of ink are ejected; a charge electrode adjacent the nozzle face for charging selected droplets of ink; a ground plate opposite the charge electrode and adjacent the nozzle face; and a gutter for collecting droplets ejected from the nozzle array; wherein the method comprises: removing the cover from the print head assembly; providing a cleaning unit, the cleaning unit comprising a fluid chamber; a fluid intake port; and a fluid exit port; attaching the cleaning unit to the print head such that the fluid chamber surrounds a portion of the print head; introducing a solvent into the fluid chamber to contact the print head; allowing the solvent to clean the print head; and removing the solvent from the chamber.