Single pass electrostatic color printer/plotter having straight paper path

摘要

A color printer/plotter includes a frame having a paper inlet, a number of print stations, and a paper outlet. The paper is pulled past the print stations by a single driver at the paper outlet. Each print station includes a electrostatic charging head having a flat charging surface against which a first roller, typically having a foam outer surface, presses with the paper therebetween. Immediately downstream of the charging head a toner roller supplies toner to the paper, the toner adhering to the charged areas on the paper. A second pressure roller presses the paper against the toner roller. The second pressure roller is offset slightly upstream of the center of the toner roller to aid toner roller-paper contact. The sizing and positioning of the toner and second pressure rollers is such so as not to significantly deflect the paper from the substantially straight paper path between the paper inlet and paper outlet. Registrations marks are printed along the lateral edges of the paper to allow the printer/plotter to compensate for any lateral shifting or longitudinal stretching of the paper.