Patent ID: 7043175
Filing Date: 2006-05-09
Classification: G03G,Y10S

Abstract:
1. An image forming apparatus, comprising: an image-bearing member, a charging means for charging the image-bearing member, an electrostatic latent-image forming means forming an electrostatic latent image on the charged image-bearing member, a developing means including a magnetic toner and a toner-carrying member for transferring the magnetic toner carried on the toner-carrying member onto the electrostatic latent image to form a toner image thereon, and a transfer means for electrostatically transferring the toner image on the image-bearing member onto a transfer material via or without via an intermediate transfer member, wherein the charging means comprises a charging member supplied with a voltage and abutted against the image-bearing member to form a contact nip with the image-bearing member, the charging member is a roller member having a volume resistivity of 10 the image-bearing member comprises an electroconductive support and a photoconductor layer comprising a silicon-based non-single crystal material and disposed on the electroconductive support, and is charged to a potential of 250 to 600 volts in terms of an absolute value via the charging member abutted against it, the magnetic toner includes magnetic toner particles comprising at least a binder resin, a wax and a magnetic iron oxide, and inorganic fine powder and electroconductive fine powder present at the surface of the magnetic toner particles, the magnetic toner has a weight-average particle size of 4-8 μm, the magnetic toner has an average circularity of 0.950 to 0.995, and the magnetic toner contains 0.10 to 1.50% of isolated iron-containing particles, the electroconductive fine powder has a volume-average particle size of 0.8 to 3.6 μm, the wax is present in the magnetic toner in a proportion of 0.1 to 20 wt. % based on the total weight of the magnetic toner, a surfacemost layer of the image bearing member comprises a non-single crystal carbon hydride film, and the roller member has a surface provided with minute cells providing an average spherical cell diameter of 5-300 μm and a void areal percentage at the surface of 15-90 %.