| 摘要 |
PURPOSE:To provide a transfer device not scattering toner and having no generation of a transfer mottle image, etc., by composing the surface of a transfer roller of a dielectric layer and holding a toner image by means of the movement of the charge of a roller surface layer to a transfer material. CONSTITUTION:An electrifying roller 30 is provided with the low resistance rubber layer 32 of a carbon dispersion EPDM, etc., on a core metal 31 and a urethane layer and an epichlorohydrine rubber layer which have the dispersion of carbon on the surface of the layer 32, as a resistance control layer 33. A voltage obtained by superimposing a DC voltage on an alternating voltage is impressed on the core metal 31 by an external power source 40. Then, a charge supplied by the electrifying roller 30 exists on the surface of the dielectric layer of the transfer roller 50. When the charge is held between the transfer roller 50 and a photosensitive drum 1, the charge acts as a transfer material rear surface charge, to form a transfer electric field between the surfaces of the photosensitive drum 1 and the transfer material. Moreover, the charge supplied by a primary electrifier and one processed by the toner image exist on the photosensitive drum 1. |
