| 摘要 |
PURPOSE:To obtain a sharp recording image having no fog stably by varying other image formation conditions according to variation in the toner concentration of the developer in a developer reseroir. CONSTITUTION:The latent image of a reference concentration test-piece is developed by a developing device 9 and passed through a transfer electrode 10 and a separation electrode 11 without being transferred to recording paper P, and its reference development concentration is detected by a development concentration detector 12, whose detection signal is inputted to a main controller 14. On the other hand, the toner concentraton detection signal of the toner concentration detector 15 in the developer reservoir 91 is inputted to the main controller 14. The controller 14 controls the bias voltage of a developing device 9 according to variation in toner concentration. Thus, a sharp recording image having no fog is obtained stably. |
