| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can suppress the generation of density irregularity, toner dropping and further a developing roller set mark image by making toner coat condition on the developing roller homogeneous in a contact developing method. <P>SOLUTION: A direct current voltage applied to a developing blade 5 is equal to the direct current voltage applied to the developing roller 2, or the direct current voltage applied to the developing blade 5 is on the charge polar side of a developer rather than the direct current voltage applied to the developing roller 2 and the following relations are satisfied: 4.2×v≤f≤2,500, 2.2×10<SP>6</SP>≤E≤5.2×10<SP>6</SP>, wherein frequency of alternate current electric field formed between the developing blade 5 and the developing roller 2 by an alternate voltage applied to the developing blade 5 is f(Hz), strength of electric field of the peak of alternate current electric field is E(V/m) and circumference speed of a photoreceptor drum 1 is v(m/s). <P>COPYRIGHT: (C)2007,JPO&INPIT |
