| 摘要 |
PURPOSE:To stabilize development conditions in toner development for the patch latent image formed on a photosensitive body even if the dark attenuation quantity of the latent image potential of the patch of this photosensitive body increases with lapse of time. CONSTITUTION:The patch latent image is formed on the photosensitive body 1 by a patch exposing means 3 and the potential of this patch latent image is detected by a latent image potential detecting means 4. The potential in the developing machine position of the patch latent image is predicted in accordance with the potential of the previously detected patch latent image from a relation between the previously detected dark potential at the time of non-exposing of the photosensitive body 1 and the grid impression voltage by an electrostatic charge potential control means 8 and the developing bias voltage is so controlled as to maintain the predicted potential of the patch latent image and the developing bias voltage at a specified relation by a developing bias control means 9. The patch latent image on the photosensitive body 1 is developed with toners by the developing machine 5 in accordance with the controlled developing bias voltage. The density of the patch after the development is detected by a development density detecting means 6 and the supply rate of the toners to the developing machine 5 is controlled in accordance with the detected density. |
