| 摘要 |
PURPOSE:To obtain a clear copy without reverse copying by providing as semi-transparent reverse side reflecting plate so as to position it at the exposure part of an original and then providing a reflected luminous energy changing means which detects the transmissivity of the original transported to the exposure part and varies the reflected luminous energy in accordance with the transmissivity. CONSTITUTION:Prior to transporting the original 21 to the exposure part 20, a detector 29 detects the transmissivity of the original 21, controls the luminous energy of a back light lamp 28 according to the transmissivity, and varies the reflected luminous energy from the reverse side reflecting plate 26 by means of a lighting lamp 22, when the original 21 is exposed. When a thin double-side original having pictures on its both sides is copied, the reverse side of the original is darkened according to the transmissivity by controlling the irradiated luminous energy of the lamp 28 so that the picture on the reverse side will not be reflected. Accordingly the surface potential of the entire base on a photosensitive body is raised, for instance, a developer bias potential is also raised, thereby obtaining the copy without reverse copying. Moreover even if low density pictures lie on both sides of the original 21, they can be reproduced on a copying paper without omission. |
