| 摘要 |
PURPOSE:To optimize copying density by entering a photodetector removably provided on an optical path near a lit to said path at the time of photometry and retreating the photodetector outside the optical path at the time of exposure. CONSTITUTION:The image forming device slit-exposing an optical image on an image carrier 12 and forming an image is provided with a light quantity detecting means 16 which retreats the photodetector from the optical path near the image carrier 12 at the time of slit-exposure, whereas on any occasions other that slit-exposure, positions the photodetector on the optical path, and which adjusts image density based on detected light quantity. Namely, in the midst of photometry, the photodetector removably provided on the optical path near the slit is entered the optical path, while it is retreated outside the optical path in the midst of exposing. Thus, exposure quantity and a developing bias can be controlled based on the detected value which is obtained in the midst of photometry, so that image density can be optimized. Consequently, the image density can be controlled precisely, and a low-priced, miniaturized image forming device can be obtained. |
