| 摘要 |
PURPOSE:To form a high-quality bicolor picture in a short time with an easy adjustment, by changing only the first optical image exposure to adjust the density. CONSTITUTION:An original 3 is scanned and irradiated by light sources 6a and 6b in different positions, and reflected lights 27a and 27b become exposure lights of a black part and a red part of the original through cyan and red filters 13 and 14 respectively, and a photosensitive drum 1 is exposed to these lights. By this constitution, only the exposure of the drum 1 corresponding to the black part of the original 3 is adjusted when only the quantity of light of the light source 6a is changed, and the exposure corresponding to the red part of the original 3 is not changed, and the density of a black latent image formed on the drum 1 is adjusted without the influence upon a red latent image in accordance with the variance of unevenness of the density of the black part due to pencil-written or printed data on the original 3. The red latent image on the drum 1 is developed in a red developing device 15, and the black latent image formed by an overall exposure lamp 16 following the device 15 is developed with a black toner having the polarity opposite to that of the device 15 by a black developing device 16, and thus, a high-quality bicolor picture is formed in a short time during one rotation of the photosensitive drum with a simple constitution. |
