| 摘要 |
PURPOSE:To execute multisheet copying by once exposure, by repeating development and transfer using one latent image obtained by imagewise exposure, when image density deteriorates, uniformly charging a toner image, then, removing the toner image, developing a photosensitive surface, and obtaining a positive or negative toner image. CONSTITUTION:A photoreceptor P having a photoconductive layer 12 on a conductive substrate 11 is, for example, positively charged (1), imagewise exposed (2), developed (3) with a toner 16, and the image is transferred (4) on a copying paper 17. The steps (3), (4) are repeated, but when copy image density lowers, the toner image is not transferred but uniformly exposed and at the same time positively charged (5), further positively charged (6), and the toner 16 is removed (7) by cleaning or transferring. Then, after reversal development (8) with a positive toner 23, transfer (9) is made, and these steps are repeated till deterioration of image density. Alternatively, the latent image obtained in the step (7) is developed (8') and transferred (9'), thus permitting multisheet copying to be executed by one exposure. |
