Image forming apparatus having a toner collecting mechanism for removing foreign particles from the copier environment

摘要

An electrophotographic image forming apparatus capable of collecting a toner remaining on a photoconductive element after image transfer. A developing device develops a latent image electrostatically formed on the surface of a photoconductive element. A paper and paper dust, paper fibers and other impurities produced from the paper before, after and during image transfer are caused to electrostatically adhere to a transfer belt included in a contact type transferring device. After the developed image has been transferred to the paper, a cleaning device associated with the photoconductive element removes a toner remaining thereon. The tone so collected by the cleaning device is conveyed to the developing device by a transporting device. Impurities deposited on the transfer belt are not conveyed to the developing device. An arrangement of a bias roller having a transfer bias from a high-tension power source and a contact plate located downstream of the bias roller ensure not only that the impurities remain on the transfer belt but also reduce reverse charging during image transfer with the result that most of the residual toner reaches the drum cleaning device while preserving the original polarity thereof.