Self-cleaning ink jet printer system with reverse fluid flow and rotating roller and method of assembling the printer system

摘要

Self-cleaning printer system with reverse fluid flow and rotating roller and method of assembling the printer system. The printer system comprises a print head defining a plurality of ink channels therein, each ink channel terminating in an ink ejection orifice. The print head also has a surface thereon surrounding all the orifices. Contaminant may reside on the surface and also may completely or partially obstruct the orifice. Therefore, a cleaning assembly is disposed relative to the surface and/or orifice for directing a flow of fluid along the surface and/or across the orifice to clean the contaminant from the surface and/or orifice. The cleaning assembly includes a rotatable roller disposed opposite the surface or orifice and defining a gap therebetween. Presence of the rotating roller accelerates the flow of fluid through the gap to induce a hydrodynamic shearing force in the fluid. This shearing force acts against the contaminant to clean the contaminant from the surface and/or orifice. A pump in fluid communication with the gap is also provided for pumping the fluid through the gap. As the surface and/or orifice is cleaned, the contaminant is entrained in the fluid. A filter is provided to separate the contaminant from the fluid. In addition, a valve system in fluid communication with the gap is operable to direct flow of the fluid through the gap in a first direction and then in a second direction opposite the first direction to enhance cleaning effectiveness. Moreover, the print head itself has integral passageways formed therein for conducting the flow of fluid to the surface of the print head.