| 摘要 |
<p>PROBLEM TO BE SOLVED: To make it possible to assure a sufficient triboelectrostatic charge quantity and transportation quantity in the magnetic toners of a one-component developer on a developing sleeve of a developing device even if a metallic layer is formed on the surface of the developing sleeve and to obtain images maintaining densities and image quality for a long period of time even in image formation of a reversal development system using a positive magnetic toner by using an amorphous silicon drum as an image carrying member. SOLUTION: The surface of the developing sleeve is subjected to plating of a nonmagnetic metal. The work function of this plating layer and the work function of the magnetic toners satisfy the relation 0.1eV<=|(the work function of the plating layer - the work function of the toners)|<=1.0 eV. More preferably, the thickness of the plating layer is specified to 3 to 20μm and the hardness Hv thereof to 450 to 1000. The developing sleeve is subjected to a surface roughening treatment before the plating and the roughness Ra after the plating of the surface is specified to 0.6 to 1.4μm. The photosensitive drum is composed of the amorphous silicon drum and the developing sleeve is made of aluminum.</p> |
