| 摘要 |
PURPOSE:To restrain the deterioration of image quality without consuming a large amount of toner in the case of initially feeding developer into a developing device or exchanging the developer in the developing device. CONSTITUTION:When the developer whose toner concentration is lower than ordinary one is fed into the developing device in the case of initially feeding it or exchanging it, the developer is electrostatically charged in a state where the supply of toner is stopped until a specified time elapses so as to increase the electrostatically charged amount of the developer (steps 152 and 154). Next, the supply of toner is started (step 156) and an electrostatic latent image being a patch image is formed and developed in every specified time. The toner is supplied until the density D of a toner image becomes equal to or above a reference value D2, and the developer is electrostatically charged (steps 158 to 162). When the density D is equal to or above the reference value D2 and the electrostatically charged amount of the developer and the toner concentration and the electrostatic charging distribution of the toner become nearly equal to the ordinary state, the supply of toner and the electrostatic charging of the developer are stopped and forming the electrostatic latent image is stopped. |
