| 摘要 |
PURPOSE:To prevent occurrence of contamination in a machine due to a remaining toner, by executing the exposure by effective image size corresponding to width and length of smaller one of an original or recording paper. CONSTITUTION:A toner stored in a developing device is charged to positive polarity to the same polarity as charge polarity of a photoconductive drum 12 in advance, therefore, development is executed as reverse development, by which a toner image being a positive picture is obtained. This toner image is overlapped on transfer paper 5 which is fed to the photoconductive drum 12 as shown with an arrow D, and after that, is transferred on the transfer paper. On the other hand, in the reverse development, the toner adheres onto the part to which light on the photoconductive drum 12 has been irradiated, but this part is always contained in the exposure range, and also its exposure range is limited to size of smaller one of an original 1 or transfer paper 5, therefore, a toner does not adhere onto the drum 12 outside of the effective image-size, and after transfer has ended, no toner is left on the drum 12. |
