| 摘要 |
PURPOSE:To improve the peeling performance by detecting the toner concn. of a developer conveyed by a developing device and changing peeling conditions for a peeling part according to the result of detection. CONSTITUTION:The developer 32 is attracted to the surface of a roller 33 and moves together with a developing roller 33 toward an arrow (b) direction when a photosensitive drum 11 on which an electrostatic latent image is formed rotates in an arrow (a) direction and the roller 33 rotates in the arrow (b) direction. The developer 32 contacts slidingly with the drum 11 to end development. The developer 32 attracted to the roller 33 is recovered into a housing 31. The developer 32 is measured by a measuring part 37 in the lower part of the roller 33 in this stage and the rate rho of a decrease in the toner concn. is operated. The electrostatic charge voltage of an electrifier 24 for peeling is set at 5.5kV in the case of 0-0.1 rate rho of the decrease, is set at 4.9kV in the case of 0.1- 0.25 and is set at 4.5kV in the case of >=0.25. The peeling conditions are thus varied exactly according to the image and the peeling performance is improved. |
