| 摘要 |
PURPOSE:To always obtain a sharp stable copied image by obtaining information with respect to the sensitivity of a photosensitive body based on a toner image formed on the photosensitive body and setting the quantity of light with which the photosensitive body is irradiated with the sensitivity information. CONSTITUTION:An optical sensor 12 detects the reflectance of the toner image on the photosensitive body as the density of the toner image. For turning this toner concn. into the sensitivity information of the photosensitive body, first, it is electrified with a prescribed voltage to impart a constant surface potential to the photosensitive body, the illuminating unit of an optical system 6 is moved under a standard white sheet 15 and a copy lamp 6a is successively turned on with various kinds of voltages, so that the electrostatic latent image patterns of different surface potentials are formed on the photosensitive body and actuarized to measure the reflectance by the optical sensor 12. Then, the quantity of light with which the photosensitive body is irradiated such as the light quantities of a destaticization lamp and a blank lamp. Thus, the drop of the surface potential can be prevented under low temperature environment and consecutive processing as well, especially in the initial stage of the use of the photosensitive body. |
