Abstract: An apparatus in which an advancing sheet is guided along a paper path. The apparatus includes a non-rotating, arcuate member, positioned closely adjacent to a drive roller, defining a nip through which the advancing sheet moves. The arcuate member resiliently urges the sheet into contact with the drive roller to move the sheet between adjacent guide plates along the sheet path.

Abstract: A printing machine in which magnetically permeable marking particles develop a latent image recorded on a photoconductive member. A read head is positioned adjacent the photoconductive member to detect magnetic field intensity effects produced by the marking particles. In addition, an optical device may be used to transmit a light beam onto the marking particles developed on the latent image and to sense the intensity of the light rays reflected therefrom. The read head alone or in combination with the optical device, generates a control signal. The control signal may be used to regulate one of the processing stations of the printing machine.