| 摘要 |
PURPOSE:To permit multiple sheet copying through the utilization of the reproduced latent images by again charging the developed images having been formed on photoreceptor and forming the same latent images thereon. CONSTITUTION:Negative primary charging is done on the surface of the photoreceptor P comprising providing a photoconductive layer 2 on a conductive substrate 1. Next, the light images of the original 4 having black image parts 4b on white ground part 4a are radiated on the surface thereof the form primary latent images. In this case, in the photoreceptor region Pa opposing to the ground part 4a, the negative charges are discharged through the substrate 1 and the surface potentials thereof considerably decrease. Next, the black toner 5 having been charged positive is supplied on the surface of the photoreceptor P to perform primary development. Next, secondary charging of the polarity opposite from the primary charging is done. Next, the photoreceptor P surface is evenly exposed to form the secondary latent images similar to the primary latent images on the toner 5 images. Next, the black toner 7 having been charged negative is supplied to form the secondary toner images. Next, transfer paper 8 is superposed to transfer the secondary toner images. To perform multiple sheet copying in succession, the processes after the process of secondary charging or forming the secondary latent imges are repeated at high speed. |
