| 摘要 |
PROBLEM TO BE SOLVED: To use a reuse toner as much as possible while preventing the generation of an image tip shade. SOLUTION: A transfer residual toner recovered by a cleaning device is housed in a developing hopper 9B as a reuse toner by a carrying pipe 8, and an unused new toner is housed in a separate developing hopper 9A. Rotating speed variable magnet rollers 21A, 21B are arranged under the developing hoppers 9A, 9B to supply the new toner and the reuse toner in a developing counter 2 by the rotation. A test patch is formed on the photosensitive drum surface so that an inclination of the concentration of the tip side edge part is detected by a concentration sensor 11. A control means 23 controls a rotating speed of the magnet rollers 21A, 21B according to the detecting result, thereby adjusts the ratio of the reuse toner to the new toner in the developing counter 2. An image tip shade by too excessiveness of the ratio of the reuse toner can be prevented while reusing the reuse toner as much as possible. |
