| abstract |
(57) [Problem] To provide a developing device capable of obtaining a good image without uneven density. SOLUTION: A toner carrier 21 which holds a toner t on a surface thereof and conveys it to a developing area opposed to an image carrier 10 at a predetermined interval, and is conveyed to the developing area while being pressed against the surface of the toner carrier. The developing device includes a regulating member 23 for regulating the amount of toner, and a developing bias power supply 24 for performing development by applying an alternating electric field between the toner carrier and the image carrier in the developing region. An elastic layer 21b, an intermediate layer 21c, and a surface layer 21d are provided on the surface of the substrate, and the volume resistance value ρ1, the volume resistance value ρ2, and the volume resistance value ρ3 of the elastic layer are ρ2 ≦ ρ1 ≦ ρ3. A toner carrier satisfying the conditions and having a surface arithmetic average roughness Ra in the range of 0.8 to 2.5 μm and a toner having a volume average particle size in the range of 3 to 8 μm were used. |