| 摘要 |
PURPOSE:To eliminate the decrease in the density of a black image part and to improve a gradation characteristic by performing image exposing of an original via an A-color filter, developing the image by a beta-color toner then performing image exposing of the original via a B-color filter and developing the image by an alpha-color toner. CONSTITUTION:A photosensitive body 1 is uniformly electrified by a corona charger 2 and an original is illuminated by an exposing lamp. The reflected light is exposed via a red filter 3 onto the body 1 to obtain the 1st electrostatic latent image. The image is then electrified to the polarity reverse from the polarity of the electrification by a corona charger 4 and only the part B corresponding to the black is developed by a developing device 5 using the black toner BT having a positive polarity. The original is in succession illuminated again by the exposing lamp and the reflected light is exposed via a cyan filter 6 on the body 1, thereby forming the 2nd electrostatic latent image. The electrostatic latent image is developed by a developing devce 7 using the red toner RT having the negative polarity reverse from the polarity of the potential in the part R corresponding to the red. Transferring and fixing are then executed, by which the decrease in the density of the black image part is eliminated and the two- color image having the improved gradation characteristic is formed. |
