| 摘要 |
PURPOSE:To prevent the deterioration of image quality by setting a toner supply quantity of a toner replenishment means based on the variation of the toner concentration calculated by a variation calculation means and the toner concentration. CONSTITUTION:The toner concentration is read by a magnetic sensor 3c ( toner concentration measuring sensor which utilizes an effect that magnetic permeability falls when toner is much and the magnetic permeability rises when toner is a little), and the necessary quantity of toner in a toner box 4 is dropped in a developing unit by turning a toner replenishing motor 4b so that a toner replenishment roller is rotated. Then, the toner supply quantity is obtained based on the output from the sensor 3c by fuzzy inference. Thus, the toner supply quantity is decided based on the toner concentration and its variation. Then, the temporary dispersion of the toner concentration is not found and the deterioration of the image quality is avoided. |
