| 摘要 |
PURPOSE:To secure an effective prevention of adhesion of a toner to a nonpicture region, by securing an electrifying condition under which the surface potential of the nonpicture region after formation of a latent image becomes to a level at which an attachment of toner is more difficult than that of the potential at the bright part of the picture region. CONSTITUTION:The discharge wire 2 is distributed so as to extend in the axial direction and in opposition to the circumference part of the photoreceptor drum 1. The center part of the surface of the drum 1 is the picture region 3 and the both ends of the surface are the nonpicture regions 4 each. And the area opposing to the region 4 of the wire 2 is covered with the dielectric substance 5. As a result, the corona current given from the wire 2 is reduced at the region 4 with a lower surface potential than the region 3. Accordingly a considerable difference of potential is caused between the region covered with the dielectric substance and the region that is not covered with the dielectric substance. This difference of potential differs according to the resistance and the thickness of the dielectric substance to be selected in accordance with the desired electrifying conditions. In such way, a surface potential is set at the region 4 and after formation of an electrostatic latent image with such a level at which an attachment of toner is reduced. |
