Patent ID: 8690312

Claim:
Apparatus for producing a print on paper, comprising: a transport for moving the paper along a paper path; a dryer, a liquid-deposition unit, a charging member, a development station, and a fixer arranged in that order along the paper path; the dryer adapted to dry a selected region of the paper on the transport to a moisture content not to exceed that of the paper equilibrated to 20% RH; a controller that provides image data as a command to the liquid deposition unit to eject hydrophilic liquid drops in a pattern corresponding to the image data; the liquid-deposition unit adapted to deposit hydrophilic liquid in a selected fluid pattern on the selected region of the paper within 15 seconds of the completion of drying, so that the resistivity of the paper in the selected fluid pattern becomes no greater than 5×10 11 Ω-cm.; the charging member including two electrodes arranged on opposite sides of the paper path and adapted to selectively charge the selected region of the paper between them, so that a charge pattern of charged and discharged areas is formed on the paper and the charged areas have a potential of at least 100 V; the development station including: a biasable toning member and a biasable area electrode arranged on opposite sides of the selected region of the paper; a voltage source for applying a bias to the toning member less than the potential of the charged areas of the paper and greater than the potential of the discharged areas of the paper; and a supply of charged dry ink, wherein the charge of the dry ink has the same sign as the charge in the charged areas on the paper; so that when the selected region of the paper is brought into operative arrangement with the development station, charged dry ink is deposited on the paper in a dry ink pattern corresponding to the selected fluid pattern in the selected region by electrical forces arising from the charge on the dry ink and the electric field between the toning member, the area electrode and the charge pattern on the paper; and the fixer adapted to permanently fix the dry ink to the paper; so that the print has a maximum reflection density of at least 1.5.