| 摘要 |
FIELD: physics. ^ SUBSTANCE: developing device has a developer for developing an electrophotographic latent image on a light-sensitive drum, an element which carries the developer for holding and transferring the developer and a unit for regulating thickness of the developer layer, lying near the element which carries the developer for regulating the amount of developer which is held and transferred by the element which carries the developer, which is a unit which regulates the thickness of the developer layer. The developer used is a negatively charged single-component magnetic toner, having magnetic toner particles, containing resin binder and magnetic iron oxide particles, and has a specific saturation magnetisation, specific weight-average particle diameter and specific composition. The element which carries the developer has a surface layer containing resin binder, a quaternary ammonium salt, graphitised particles and developing spherical resin particles, and has a specific surface form. ^ EFFECT: preventing fluctuation of image density during periodic print mode having a dormant period. ^ 7 cl, 9 dwg, 13 tbl |
