| 摘要 |
PROBLEM TO BE SOLVED: To obtain an excellent image over a long period, by preventing an overflow of the developer from an end part of a developing roller and clouding of the developer, in the developing device making a latent image on the image carrier visualized, with use of the one-component developer. SOLUTION: This device is provided with a toner electrification member 4 held in contact with the developing roller 2 across a thin film of the one- component developer on the developing roller 2, for electrifying the one- component developer by applying voltage between the toner electrification member 4 and the developing roller 2. In such a case, the toner electrification member 4 is composed, that the volume resitivity of a material forming the part held in contact with the visinity of a end part of the developing roller 2 is set < the volume resistivity of the part held in contact with the developing roller 2 within the image forming width. As a result, an electric discharging quantity from the toner electrification member 4 becomes larger, in the part held in contact with the visinity of the end part of the developing roller 2, therefore the electrification quantity of the toner on the developing roller 2 is raised corresponding thereto. Thus, adhesion of the toner can be made to be strong in the end part visinity of the developing roller 2. |
