Patent ID: 7937008

Claim:
An image forming method in which using a two-component developer holding body that has a magnetic member arranged thereinside and magnetically holds a developer made of a carrier and a toner, and a toner holding body that transports the toner from said two-component developer holding body and holds a toner thin layer on a surface thereof, which are provided inside of a housing, a developing bias is applied to said toner holding body and/or said two-component developer holding body to perform development of an electrostatic latent image formed on the surface of an electrostatic latent image holding body, wherein a toner collecting roller that collects scattered toner suspended in the vicinity of said toner holding body and said two-component developer holding body is arranged on the downstream side in a rotational direction of said two-component developer holding body from a closest position of said two-component developer holding body and said toner holding body, and between said two-component developer holding body and said housing wall; and a bias voltage applied to said toner collecting roller by bias means for collecting the scattered toner is controlled using a sensing result obtained by image density sensing means for sensing a density of a toner image developed on the surface of said electrostatic latent image holding body or a toner image on a transfer body onto which the toner image developed on the surface of said electrostatic latent image holding body is transferred; wherein, based on the toner density sensed by said image density sensing means, a bias difference ΔV between said two-component developer holding body and said toner holding body is set, and said bias voltage applied to said toner collecting roller is controlled in accordance with said set bias difference ΔV; and further wherein if said toner density is higher than a predetermined density, said bias difference ΔV is changed, and then an image patch is again formed and the density of said image patch is sensed by said image density sensing means to repeatedly change said bias difference ΔV until the density reaches said predetermined density.