| 摘要 |
PURPOSE:To keep relations between an original density and the output of a light receiving device constant to detect an accurate density and to rationalize stably a picture density, by correcting the output of an exposure lamp so that the output of the light receiving device of a reflected light due to a standard plate is always a certain reference value. CONSTITUTION:Before the copy generating process, a standard plate 14 provided on the outside of a picture area and an origianl 13 are irradiated by a light source 8, and reflected lights from them are measured by a light receiving device 15. The standard plate 14 has a reflection density approximately equal to that of an ordinary white original. The brightness of the light source 8 is controlled by a control circuit 16 on a basis of measured results, namely, in accordance with the density of the original, thus obtaining copies without photographic fog. |
