| 摘要 |
PURPOSE:To eliminate deteriorated toner on a developing sleeve by changing a magnetized pattern of a developing roll and changing bias voltages of the developing sleeve and a carrying sleeve to prescribed voltages in the developing roll cleaning process. CONSTITUTION:A developing roll 9 and a carrying roll 30 which have freely rotatable sleeves 10 and 31 on outside peripheries of magnetic rolls 20 and 32 having prescribed magnetized patterns are so provided that axial lines of the rolls are parallel with each other. The magnetic roll 20 of the developing roll 9 is rotated around the axis at a prescribed angle before toner sticking to a photosensitive body 2 is started or after toner sticking to the photosensitive body 2 is terminated. Bias voltages applied to the developing sleeve 10 or/and the carrying sleeve 31 are so switched that the remaining toner is attracted to the carrying sleeve 31 when the remaining toner on the developing sleeve 10 will face the carrying sleeve 31 by rotation. |
