| 摘要 |
PURPOSE:To mechanically and electrostatically prevent a developer from detouring to the outside of development width, by providing a developer control member of a band-like film having a strong cathodic polarity on the outside of the development width of a cylindrical developing member. CONSTITUTION:On the peripheral surface of a cylindrical and freely rotatable sleeve 11, a band-like film 14 is allowed to abut on a position of the outside of a prescribed development width W, and an electrifying blade 15 is provided in holding a prescribed interval to the sleeve 11 through the band-like film 14. The band-like film 14 consists of a material whose cathodic polarity is stronger than that of the sleeve 11 and an electrifying blade 15 on a frictional electrification string and the film 14 also electrifies strongly a developer, and by thickness of its own band-like film 14, the expansion of the developer is controlled mechanically, and also, and the developer electrified to the anodic polarity is adsorbed to the sleeve 11, the electrifying blade 15, and also, the band-like film 14, and its leakage to the outside of the electrifying blade 15 is prevented electrostatically, as well. |
