| 摘要 |
PURPOSE:To always obtain a copied image having a good quality, by providing a light quantity detector on an optical path of a reflected ray, detecting the light quantity of a ground part of an original, and also controlling the light quantity of an exposure lamp and a charging current of an electrifier in accordance with an obtained value. CONSTITUTION:When an original 2 to be copied is placed on a platen 3 and copying is started, an exposure lamp 4 is lighted, and a ground part of the end part of the original 2 is irradiated. A reflected ray from the ground part is led on an optical path 11 consisting of the first and the second moving mirrors 5, 6, an in-mirror 7, a fixed mirror 8, etc., reaches on a photoreceptor 10 through a slit 9, and a part of said ray is detected by a light quantity detector 12 provided in the vicinity of the slit 9.A light quantity signal detected by the light quantity detector 12 is inputted to an exposure illuminance discriminating circuit 13 so that the reflected light quantity of the ground part is discriminated. |
