| 摘要 |
PURPOSE:To always keep a toner adhering quantity on a developer carrier in an appropriate quantity and to obtain an excellent image by variably controlling the rotating speeds of a latent image carrier, the developer carrier and a toner supply regulation means and relative potential differences among them. CONSTITUTION:A developing roller 41 functioning as the developer carrier which supplies toner to an electrostatic latent image formed on a photosensitive drum 1 is driven to be rotated and a developing bias voltage VR is impressed on the developing roller 41 from a power source 42. Attending with the proceeding of developing actions, the appropriate quantity of toner which should be stuck onto the surface of the developer carrier is calculated and at least either the rotating speed ratio of the toner supply regulating means to the developer carrier or a bias voltage value for supplying toner impressed on the toner supply regulating means is variably controlled according to the calculated results. Thus, the toner sticking quantity on the developer carrier is always kept in the appropriate quantity and the excellent image can be obtained. |
