摘要 |
PURPOSE:To obtain a copy having no mixture of a specific color into a black color part, by setting the potential of a latent image higher at the part of the specific color A than at the black color part. CONSTITUTION:A photoreceptor is used when a double-color copy is produced from a double-color original of colors A and B. This photoreceptor includes a photosensitive layer 2 having no sensitivity to a specific color A plus a photosensitive layer 3 having the sensitivity to the color A and transmitting the beam. In case the colors A and B are defined to red and black respectively, the photoreceptor is first charged with electricity. Then an image is exposed to light through a red or blue color filter, and the black color part is developed with the bias potential higher than the red color part. After this, the entire surface of an original is exposed to the red color beam to set the potential of a latent image higher at the red color part than the black color part. In such way, the red color is prevented from mixing into the black color part. |