Abstract: An electrostatographic single-pass multiple station (e.g. multi-colour) duplex printer is described for forming an image onto a web. The printer has at least three toner image-producing electrostatographic stations. Each station has a rotatable endless surface in the form of a photoconductive drum onto which a toner image can be formed. The printer also includes drive rollers for conveying the web in succession past the stations. Corona discharge devices transfer the toner image on each rotatable surface onto the web. The image-producing stations are arranged in two sub-groups, the drum of one sub-group forming a backing roller for the other sub-group, and vice-versa, thereby to enable simultaneous duplex printing.

Abstract: An electrostatographic single-pass multiple station multi-color printer for forming an image onto a web, eg of paper, is described. A plurality of toner image-producing electrostatographic printing stations each have a rotatable endless surface such as the photoconductive surface of a cylindrical drum onto which a toner image can be formed. The paper web is conveyed in succession past the printing stations. The speed and tension of the web is controlled while it is running past the printing stations. Guiding rollers which determine for the web wrapping angles of about 15.degree. about the drum surface. A corona device transfers the toner image on each drum onto the web. The corona device, the wrapping angles .omega. and the web tension are such that adherent contact of the web with the drum surface is such that the moving paper web controls the peripheral speed of the drum in synchronism with the movement of the web.