| 摘要 |
PURPOSE:To make possible reproduction of the faithful gradation characteristic of the original by applying the specific charging exposure to a photoreceptor having a surface insulation layer. CONSTITUTION:A photoreceptor 1 which is provided with a conductive substrate, an N type photoconductive layer and an insulation layer is charged to the surface potential of approximately +1500V by a primary charging corona discharger 21 and is exposed with the light image of the original on an original platen 3. At the same time, it is destaticized to the surface potential of approximately -100V by a corona discharger 22 of opposite polarity and the control grid 23 provided at the front thereof. After 0.5 second, the surface potential is made to approximately +50V by a gradation-adjusting corona discharger 24 and the control grind 25 provided to the front thereof. Thereafter, full surface exposure of more than 10 lux. sec. is applied by a full surface exposure source 26, whereby electrostatic latent images are formed on the photoreceptor 1. The electrostatic latent images are developed by a developing means 5 and the developed images transferred to transfer material P by a transfer and separating means 7 are fixed by a fixing means 8. |
