| 摘要 |
PURPOSE:To conduct good developing with an adhering quantity of a carrier in a developer to a photosensitive body reduced by making the bias electric potential of a developing roll higher than the background electric potential of the photosensitive body only at the time of a developing action, and lower at other than the time. CONSTITUTION:An electrostatic latent image is suitably developed by making the bias electric potential of a developing roll 25 a given high value directly before the electrostatic latent image on a photosensitive body reaches the developing roll 25, and the bias electric potential of the developing roll 25 is made zero volt directly after the final electrostatic latent image passed the developing roll 25. This shortens time in which the difference, between the bias electric potential of the developing roll 25 and the background electric potential of the photosensitive body, is large, enabling the adhering quantity of a carrier to the photosensitive body to be reduced. |
