| 摘要 |
PURPOSE:To prevent one of photosensitive bodies which is not used during monochromatic copying operation from being irradiated with unnecessary light by fixing a luminous flux splitting means and providing luminous flux shield members so that they can be put on and off optical paths of split pieces of luminous flux. CONSTITUTION:The two photosensitiv bodies 6 and 7 are provided; both of them is used to take a dichroic copy and one photosensitive body is used to take a monochromatic copy. Luminous flux passed through an image forming lens 1 is split into reflected luminous flux and transmitted luminous flux by a half-mirror 2 fixed at a constant position, and luminous flux shield members 101 and 102 are provided on optical paths of those pieces of split luminous flux. When a black- and-red two-color copy is taken, both shield plates are set at stand-by positions shown by solid lines, and both pieces of luminous flux illuminate both drums 6 and 7, which are exposed. When a black-and-red original is so copied that only a red image is formed in red or that only a black imae is formed in black, equipment relating to either photosensitive drum is turned off and the luminous shield plate on the optical path extending to the drum is put on the optical path as shown by a broken line. |
