Patent ID: 7789504

Claim:
A printing apparatus utilizing non-marking liquid ink and marking pigmented ink, said printing apparatus comprising: a printing member including a series of substantially equal sized cells located over the surface of said printing member and having a depth relative to said surface of said printing member; an inking unit for filling cells of said printing member with pigmented ink having electrostatically charged particles to form a substantial blanket of pigmented ink on said printing member; an ink jet device for selectively ejecting droplets of non-marking liquid ink into certain of said cells of said printing member in a desired negative latent image pattern; a transport for a receiver for transporting said receiver into operative association with said printing member; and a transfer mechanism for fractionating said pigmented ink only in those cells not including non-marking liquid ink in the negative image pattern, including an electrical bias device for facilitating fractionating of said pigmented ink, and transferring such fractionated pigmented ink to said receiver.