| 摘要 |
PURPOSE:To obtain an always stabilized record by forming a monitor image on an electrophotographic sensitive body and controlling potential of a latent image formed on said body in accordance with the measured value of the monitor image density and a reference value. CONSTITUTION:A photoelectric detector 25 measures a mixing ratio of a toner in a developer and a photoelectric sensor composed of a light source and a photosensor is applied to this detector 25 to measure optical reflectance of the developer. A control circuit 26 receives a signal from this detector 25, compares it with a reference signal, and controls motion of a toner replenishing roller 12. As a result, the toner mixing ratio in the developer is controlled always to a prescribed level, and increase of fog on a background and scattering of the toner are prevented, and an always stabilized record image can be obtained. |
