| 摘要 |
PURPOSE:To prevent the inside of a copying machine from being contaminated due to a toner cloud, by using a gap between the inner and outer walls of the developing device, as an air suction passage for sucking air, and forming an insulating part in a part being adjacent to the inner wall of the developing device. CONSTITUTION:The housing of a developing roller 2 is formed by a developing deice inner wall 7 and a developing device outer wall 8 provided on its outside, and between the inner wall 7 and the outer wall 8, an air suction passage 9 for sucking air in the direction as indicated with an arrow is formed. The gap l1 between the tip of the inner wall 7 and a photosensitive body 1 is set to 1mm, and a gap l2 between the inner wall 7 and the outer wall 8 is set to 4.5mm. Also, the tip part of the inner wall 7 is formed by an insulating plate made of polyacetal, the length l3 of an insulating part 7a consisting of its insulating plate is set to about 20mm, and the inner wall of other part is made of aluminum. According to this constitution, even if the suction of air is executed by setting the wind speed of a position of a point A, for instance, to 0.5m/sec, the image on the photosensitive body 1 is satisfactory all the time, and contamination in the machine is scarcely generated. |
