| 摘要 |
An apparatus for performing a copying operation contains a photosensitive drum, a focusing optical system for directing reflected light from an original image onto the photosensitive drum, a lamp for lighting the original image, a light quantity sensor for detecting the quantity of reflected light from the original image and for controlling the quantity of light of the lamp on the basis of the detected value of the quantity of reflected light, a first filter provided in an optical path of the focusing optical system so as to cut-off light having a wavelength not longer than a predetermined value, and a second filter provided on a light-detection surface of the light quantity sensor. The second filter has a cut-off wavelength point shorter than the first filter. |
