| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the occurrence of fogging and ghosts resulting from defective electrification due to the sticking of reversed toner, over a long period of time. <P>SOLUTION: At the initial using stage of the image forming apparatus, even if an electrification auxiliary bias to be applied on an electrification auxiliary brush 7 by an electrification auxiliary bias apply power source S4 is set slightly higher, a decrease in film thickness of the surface of the photoreceptor drum 1 is small, then, a charge whose polarity is opposite to that of the toner is not excessively transmitted to the toner accumulated on the brush surface, then, the occurrence of the reversed toner causing the toner smearing of an electrifying roller 2 and the occurrence of the ghost are prevented. At the latter using stage, the reduction in the film thickness of the surface of the photoreceptor drum 1 becomes large, then, the electrification auxiliary bias to be applied on the electrification auxiliary brush 7 is set at a lower level so as not to cause the reversed toner and the ghost, then, fogging due to the toner smearing of the electrifying roller 2 is prevented. <P>COPYRIGHT: (C)2004,JPO |
