| 摘要 |
PROBLEM TO BE SOLVED: To prevent contamination of the inside of an image forming device of the electrophotographic type by efficiently sucking and removing a toner cloud that comes from a developing machine. SOLUTION: A suction device provided in the portion of a developing machine 4 downstream of a photoreceptor is provided with means for changing the wind speed distribution of suction air along the direction of the axis of the photoreceptor, such as vanes 24a, 24b, and the wind speed distribution of the suction air is varied and adjusted according to the density distribution of an image to be formed, the paper size, and the position where an image for density detection is formed. Formation of the image for density detection is effected at the timing matching the end of a job within a predetermined range while giving preference to the number of copies to be made in the job, and at the same time the wind speed distribution is adjusted; further, adjustments of the wind speed distribution are made based on the wind speed distribution that matches the characteristics of the suction device. |
