| 摘要 |
PURPOSE:To prevent variation in picture density in continuous picture formation by rotating a photoreceptor while operating an electrostatic charger, and detecting the potential difference in every rotation decreasing below a specific value and then entering into a potential control process. CONSTITUTION:A lamp 11 is turned on once a copy switch 18 is turned on, and the electrostatic charger 12 is also operated. A detector 13 measures and stores the surface potential Vn of the photoreceptor 1 for the first time. Then, the detector 13 measures the surface potential Vn+1 of the photoreceptor 1 for the second time and stored it. Further, whether nu is nu>=Vn+1-Vn or not, is judged. In this case, nu is set to such a value that the phenomenon of a rise in photoreceptor surface potential ends substantially when is greater than Vn+1-Vn and no variation in picture density appears even when the picture formation process is repeated after Vn+1-Vn<=nu. Consequently, the variation in picture dnesity is prevented in the continuous picture formation. |
