| 摘要 |
PURPOSE:To raise the quantity of light at the time of a return-motion and to erase a residual inter-image image, by providing a slit exposure original scanning start and end position detecting means and an exposure lamp light quantity variable means. CONSTITUTION:As for an inter-image image generated at the time of a return- motion after scanning when executing the slit exposure, the ground of an original and the line picture part are integrated continuously within the slit width, and the density becomes higher than the integrated original ground. It is proportional to a picture area in the original and the density, and usually the reflection factor becomes 10-20% lower than that of the ground part. Accordingly, when the quantity of light of an exposure lamp is increased about 20% or more at the time of a return-motion, the inter-image image becomes density of the ground part or below and is not generated as fog. From the point of time when an exposure scanning start position detecting switch S1 of the original is stepped, the going-motion scanning is started, is ended by a switch S2 of the end and is shifted to the return-motion scanning, from which the quantity of light of the lamp is increased about 20%. |
