Patent ID: 7218883

Claim:
An image forming apparatus comprising: an image transfer carrying means having flexibility and having an endless sleeve-like shape; and a plurality of image forming means which are arranged along an arcuate oblique line of the image transfer carrying means such that respective image carriers thereof are in contact with the image transfer carrying means, each image forming means comprising a latent image forming means for forming a latent image on the image carrier and a developing means for developing the latent image formed on the image carrier; wherein a wrapping angle of the image transfer carrying means relative to the image carrier of each image forming means is defined by the curvature of the arcuate line, and a nip width and a contact pressure are defined by the wrapping angle and by the tension of the image transfer carrying means so that the developed toner images of the respective image forming means are transferred and superposed on the image transfer carrying means one by one; wherein the image carriers of said image forming means and said image transfer carrying means are set to have velocity difference therebetween; and wherein the image transfer carrying means is laid around at least two rollers, and the position of the driving roller is selected to the upstream side or the downstream side according to the velocity difference relative to the image carriers.