Abstract: A two-component developing agent containing a carrier which can maintain a charge-imparting property to a toner at a high level for a long period of time, does not generate flying of the carrier and can correspond to an image forming apparatus of present day having a long operation life and can form a high-quality image having high image density and sharpness, is provided. In the two-component developing agent containing a carrier in which a resin coating layer is formed on a surface of a core material, and a toner, in which an X-ray intensity of an alumina particle by a fluorescent X-ray analysis, the amount of the alumina particle to be used to the resin coating layer is adjusted such that it comes to be smaller than the X-ray intensity by the fluorescent X-ray analysis of a metal contained in a largest amount in the core material.

Abstract: A carrier excellent in durability and environmental stability and a two-component developing agent is provided. In the carrier, a core material is coated with a resin, and the coating resin is formed on the core material such that the coating resin comes to be in an amount of 5% by weight to 20% by weight on the basis of a weight of the core material, thereby enhancing durability. Further, the coating resin contains fine particles of titanium oxide, thereby enhancing environmental stability.

Abstract: A non-magnetic single component developing device that is included in combination with a photoreceptor in an image forming apparatus 1 of the electro-photographic system. The non-magnetic single component developing device includes a developing roller, a supplying roller, a doctor, a toner bath and a stirring blade. The supplying roller contains a rubber foam at least in its surface layer portion, the rubber foam including closed cells and open cells and having a foam ratio (porosity) of 0.75 to 0.85 and an average foam cell diameter of 350 to 500 ?m.

Abstract: A two-component developing agent containing a carrier which can maintain a charge-imparting property to a toner at a high level for a long period of time, does not generate flying of the carrier and can correspond to an image forming apparatus of present day having a long operation life and can form a high-quality image having high image density and sharpness, is provided. In the two-component developing agent containing a carrier in which a resin coating layer is formed on a surface of a core material, and a toner, in which an X-ray intensity of an alumina particle by a fluorescent X-ray analysis, the amount of the alumina particle to be used to the resin coating layer is adjusted such that it comes to be smaller than the X-ray intensity by the fluorescent X-ray analysis of a metal contained in a largest amount in the core material.

Abstract: A carrier excellent in durability and environmental stability and a two-component developing agent is provided. In the carrier, a core material is coated with a resin, and the coating resin is formed on the core material such that the coating resin comes to be in an amount of 5% by weight to 20% by weight on the basis of a weight of the core material, thereby enhancing durability. Further, the coating resin contains fine particles of titanium oxide, thereby enhancing environmental stability.

Abstract: A non-magnetic single component developing device that is included in combination with a photoreceptor in an image forming apparatus 1 of the electro-photographic system. The non-magnetic single component developing device includes a developing roller, a supplying roller, a doctor, a toner bath and a stirring blade. The supplying roller contains a rubber foam at least in its surface layer portion, the rubber foam including closed cells and open cells and having a foam ratio (porosity) of 0.75 to 0.85 and an average foam cell diameter of 350 to 500 ?m.