Patent ID: 8583011
Filing Date: 2013-11-12
Classification: G03G

Abstract:
1. An image forming apparatus, comprising: a positively-charged single layer type electrophotographic photoreceptor; a charging device that has a contact charging member for charging a surface of the photoreceptor; an exposure device for exposing the charged surface of the photoreceptor to light to form an electrostatic latent image on the surface of the photoreceptor; a developing device for developing the electrostatic latent image into a toner image; and a transfer device for transferring the toner image from the photoreceptor to a transferred body, wherein the contact charging member is a charging roller, which is made of electrically conductive rubber having an Asker-C rubber hardness of 62 to 81°, and a roller surface roughness of the charging roller of the contact charging member is such that an average distance (Sm) between asperity peaks on a cross-sectional curve is 55 to 130 μm and that a ten-point average roughness (Rz) is 9 to 19 μm, the positively-charged single layer type electrophotographic photoreceptor has a conductive substrate and a photosensitive layer, the photosensitive layer contains a charge generating agent, charge transfer agent and binder resin together, a yield point strain of the binder resin is 9 to 29%, and the binder resin is a polycarbonate resin having a viscosity-average molecular weight of 45,000 to 75,000 and a recurring unit expressed by one of the formulae (15) to (17): wherein the number “50” in the formula (17) indicates that the binder resin of the formula (17) is copolymerized at a copolymerization ratio of 50%.