| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device capable of properly controlling the density of a toner and capable of realizing those by simple constitution even when a variation in the relation between a developer quantity and Cin (image occupancy ratio of toner) is generated due to the fluctuation of the toner concentration of a developer or the potential of a latent image or the relation between the developer quantity and the Cin is changed due to the secular deterioration of a developing material. SOLUTION: The image forming device is provided with a developing means 1 obtaining a toner image by developing an original image and an electrostatic latent image of a pattern for detecting the density formed on an image carrier by a prescribed developing bias voltage, a detection means 2 detecting the density of the toner image of the pattern for detecting the density and a density control means 3 controlling the density of the toner image of the original image based on the density of the toner image of the pattern for detecting the density. Further, it is provided with a developing bias control means 4 controlling the developing bias voltage so that developing property is more lowered than the case that the electrostatic latent image of the original image is developed when the electrostatic latent image of the pattern for detecting the density is developed by the developing means 1. Then, the density of the toner image of the original image is controlled based on the density of the toner image of the pattern for detecting the density whose an image occupancy ratio is high by the density control means 3. |
