| 摘要 |
PURPOSE:To always obtain a copy having stable image quality, by providing plural reference targets having densities different from one another, and arranging them on a moving body so as to accord the position of any of them with that in which density can be detected. CONSTITUTION:A detection signal produced from a detector 10 is amplified in an amplifying circuit 15, sent to a comparator circuit 16 to compare it with the reference density signal of a reference circuit 10, and this result is delivered to a central control circuit 18, where a control mode is selected in accordance with the density decided result fed from the circuit 16, and a control signal is sent to each control circuit 20 through an output circuit 19. The image density detected from the toner image of a reference target 3 is compared with the preset reference density, thus permitting a developing bias voltage, a light intensity of an exposure lamp 4, an amount of toner to be fed to a developing device 7, a charging current to a charger 25, etc. to be controlled in accordance with this decided result. |
