Patent ID: 6550892
Filing Date: 2003-04-22
Classification: B41J

Abstract:
An ink jet printing system for delivering droplets of selectable-color ink to a receiver; the system comprising:a print head having at least one ink ejecting chamber; a nozzle opening associated with each of the at least one ejecting chamber through which nozzle opening ink droplets are delivered from the associated ejecting chamber to the receiver; a conduit in fluid communication with each of the at least one ejecting chamber; a plurality of sources of color liquid ink, each source (1) containing liquid ink of a different color and (2) communicating with the conduit; a source of colorless liquid ink communicating with the conduit to provide a flow of colorless liquid ink into the conduit for delivery into the at least one ejecting chamber; a flow controller adapted to selectably meter ink from said sources of color liquid ink into the conduit between the source of colorless liquid ink and the at least one ejecting chamber, whereby ink slugs of selectable color are prepared in the conduit by controlled delivery of selected amounts of different color inks, said slugs being separated one from another along the conduit by colorless liquid ink; and an ejector associated with each of said ejecting chambers, the ejector being adapted to cause an ink droplet to be expelled from the ejecting chamber through the nozzle opening, wherein the ejector is a thermally-driven flipper paddle.