| 摘要 |
PURPOSE:To enable good images to be obtained from different latent images by applying uniform electrostatic charging to the whole surface of a photosensitive drum after developing the first latent image, maintaining the potential difference between the exposed parts of the second latent image and the first developed part and lowering the DC current component of the second developing bias than the surface potential of the first developed part. CONSTITUTION:In the step ( I ), a photosensitive body A prepared by forming an Se photoconductive layer a1 on an electrically conductive layer a2 is electrostatically charged with a corona discharger C1; in the step (II), the first exposure L1 to optical image information in the form of format or the like is executed to form the first electrostatic latent image, and, at that time, the surface potential is decayed; in the step (III), bias voltage is impressed to the magnetic sleeve of the first developing device having a binary developer composed of, e.g., a positive red toner T(R) and an iron powder to reversely developing the exposed part; in the step (IV), the surface of the photosensitive body A is corona discharged opposite in polarity to the primary charging with a charger C2; in the step (V), the second scanning exposure L2 is executed to form the second latent image; and in the step (VI), e.g., a black magnetic positive insulating TB is spread on the developing sleeve to carry out jumping development and reversely develop the second latent image. |
