Patent ID: 6996361
Filing Date: 2006-02-07
Classification: G03G

Abstract:
1. A full-color electrophotographic apparatus to form a full color image on a printing medium using a nonvolatile, high-viscosity, high-concentration liquid toner, comprising: an intermediate transfer member on which color toner images in a plurality of colors are sequentially superimposed so as to form the full-color image, and the full-color image being heat-melt-transferred to the printing medium; a photoconductor member to form the color toner images, the intermediate transfer member being maintained at a temperature equal to or higher than a softening start temperature of resin contained in the liquid toner and equal to or lower than a withstand temperature of the photoconductor member; a carrier-removing mechanism provided on the intermediate transfer member so as to remove a carrier when each of the color toner images is transferred to the intermediate transfer member, said carrier-removing mechanism comprising a carrier-removing roller to which a bias having a same polarity as that of particles of the toner on the intermediate transfer member and in rotary contact with the toner images on the intermediate transfer member so as to remove the carrier while packing the toner softened by a force of an electric field induced by the bias; a transfer section, comprising a backup roller, to press against the printing medium the toner images which have been formed on the intermediate transfer member and from which the carrier has been removed, to thereby transfer the toner images to the printing medium; a fixation section for fixing the transferred toner image; means for heating, before the transfer to the printing medium, the toner images formed on the intermediate transfer member to a temperature higher than a glass transition temperature of toner solids and lower than a melting point of the toner solids, wherein a bias voltage is applied in such a direction as to transfer the toner images to the printing medium at the time of toner image transfer to the printing medium, in a zone for transferring the toner images on the intermediate transfer member to the printing medium, the backup roller applying a low pressure capable of transferring the toner images on the intermediate transfer member to the printing medium, and the fixation section is configured in such a manner as not to be drivingly linked to an image formation section including the intermediate transfer member, the photoconductor member, and a development section, to apply a sufficient pressure for enhancing cohesion of the toner to the printing medium which is insufficient at the time of transfer, while being heated to a temperature higher than the melting point of the toner solids; means for setting temperature such that a temperature (T a preheating unit for preheating the printing medium to a temperature required for transfer before the printing medium is fed to the transfer section; and means for controlling a temperature (T