| 摘要 |
PURPOSE:To impart sufficient surface change to a photoreceptor having 3 photoconductive layers different from each other in spectral sensitivity and to obtain a sharp 2-color image, by providing an absorption filter for cutting a specified wavelength light between an exposure lamp and discharge wires in the casing of a primary charger. CONSTITUTION:Exposure lamp 29, filter 34 for transmitting >=600nm wavelength red light, filter 35 for absorbing >=700nm wavelength red light, light quantity controlling ND filter 36, transparent conductive filter 37 made of nesa glass for enhancing discharge efficiency, and discharge wires 38 are arranged in change case 28 of primary changer 15. Primary charging is conducted under illumination of a red light, first photoconductive layer 12 is made conductive by >=700nm wavelength red light transmitted by second photoconductive layer 13, and deficient charging is prevented on the surface of photoreceptor 10, thus permitting the surface of receptor 10 to be sharply developed with black toner TB and red toner TR by the following secondary charging in the dark and imagewise exposure. |
