Patent ID: 7221893

Claim:
An image forming apparatus, comprising: a print section including a plurality of print units arranged along a transport path for a continuous paper for sequentially transferring respective color toner images in registration onto the continuous paper, wherein each of the plurality of print units includes a rotatable image carrier device, a charger device that charges a surface of the image carrier device at a predetermined surface potential, an exposure device that exposes the image carrier device to decrease the surface potential thereby to form a latent image on the image carrier device, a development device that develops the latent image on the image carrier device into a toner image, and a transfer device, disposed to face the image carrier device across the transport path for the continuous paper, that transfers the toner image on the image carrier device onto the continuous paper; a continuous paper transport section, provided on an upstream side of a transport direction of the continuous paper, that transports the continuous paper toward the print section; a fixing section provided on a downstream side of the transport direction of the continuous paper for fixing unfixed toner images onto the continuous paper, the unfixed toner images being formed at the print section and transferred onto the continuous paper; a tensioning mechanism that imparts a predetermined tension to the continuous paper having the toner images fixed thereon; and a control unit for preventing a color-to-color misregistration state which tends to occur when respective color toner images are sequentially transferred to be overlaid onto the continuous paper, wherein the control unit controls, for each one of the plurality of print units, one or more of an exposure timing of the exposure device, a rotation speed of the image carrier device, and a transfer bias voltage applied to the transfer device, based on a coverage of a toner image formed on the image carrier device.