Patent ID: 8780147

Claim:
Apparatus for producing a print on a semiporous recording medium, comprising: a transport that moves the semiporous recording medium along a transport path; a dryer, a liquid-deposition unit, a charging member, a development station, and a fixer arranged in that order along the transport path; the dryer dries a selected region of the semiporous recording medium to a moisture content not to exceed that of the recording medium equilibrated to 20% RH; the liquid-deposition unit deposits hydrophilic liquid in an image-wise selected fluid pattern on the selected region of the recording medium within 15 seconds after the completion of drying, whereby a wetted area of the recording medium is produced so that the resistivity of the wetted area of the semiporous recording medium becomes no greater than 5×10 11 Ω-cm; the charging member charges the selected region of the recording medium so that a charge pattern of charged and discharged areas is formed on the recording medium and the charged areas have a potential of at least 100 V; and the development station deposits charged dry ink in a dry ink pattern corresponding to the image-wise selected fluid pattern, the dry ink having charge of the same sign as the charged areas, wherein the charged dry ink is deposited on the paper in the dry ink pattern corresponding to the image-wise selected fluid pattern in the selected region by electrical forces arising from the charge on the dry ink and the electric field between the development station and the charge pattern on the paper.