| 摘要 |
PURPOSE:To improve throughput by detecting the density of an original, which is carried onto an exposure plane, in a carrying path, correcting the amount of light for an exposure lamp, untile the original is positioned on the exposure plane, and correcting the level of an original density sensor when the original is not in the carrying path. CONSTITUTION:The density of the original, which is carried onto a platen glass 12 by means of an original carrying means, is detected in the carrying path I(a), and then an appropriate amount of exposure is calculated based on the detected density. Untile the original is positioned on the platen glass 12, the amount of light for the exposure lamp is corrected based on the appropriate amount of exposure which has been previously calculated. When the original is not in the carrying path I(a), the level of the original density sensor is corrected. Thus, the density of the original is accurately detected even in case the sensor drifts due to a temperature or dirt such as paper chip is produced; and the throughput is improved. |
