| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus with a developing device which can easily redress the balance between a bias formed between a developing roller and a photoreceptor and a bias formed between the developing roller and a magnetic roller, while making the adhesiveness of toner on the developing roller excellent and excellently performs the formation of a toner thin layer onto the developing roller and the recovery of the toner of the developing roller, thereby improving developability with respect to the photoreceptor and suppressing image defects such as image irregularities. <P>SOLUTION: The developing roller 2 made of aluminum is anodized in an acid aqueous solution, seal treated by a nickel acetate solution and then, acid cleaned, to be surface-treated by fluorinated particles. The thickness T of the toner thin layer 6 formed on the developing roller 2 is 7 μm≤T≤13 μm and a first AC bias in a first bias forms a rectangular wave and the duty ratio D1 of the first AC bias satisfies the relation of 35%≤D1≤70%. <P>COPYRIGHT: (C)2009,JPO&INPIT |
