| 摘要 |
PURPOSE:To obtain a specified image density by changing the quantity of the toner on a developing roller so as to prevent a change in the quantity of toner sticking to the surface of a photosensitive drum, caused by the change in developing electric field intensity obtaining a constant image density, when the clearance of the surfaces of the photosensitive drum and the developing roller is changed by the eccentricity of the photosensitive drum and the developing roller, and the developing electric field strength is changed. CONSTITUTION:A developing device 2 is disposed at a constant position inside a copying machine, so that the other ridge part of a plate-like layer-thinning blade 5 made of an insulating elastic material, provided so that one ridge part of the top end part of the blade 5, comes into contact with the surface of the developing roller 5, comes into contact with the surface of the photosensitive drum 1. The thickness of the layer-thinning blade 5 is set so that the size of the clearance of the surface of the photosensitive drum 1 and the developing roller is suitable for developing. When the clearance is reduced, the pressurized- contact of the layer-thinning blade 5 is increased, and the height of toner layer is reduced, on the contrary, when the clearance is increased the height is increased. |
