| 摘要 |
PURPOSE:To expose the pages of a spread book, etc., as well properly by dividing an image on an original platen into two in a scanning direction and exposing the divided areas according to image density data corresponding to the divided area. CONSTITUTION:An original 30, e.g. spread book is placed on the original platen 1 and scanned by a scanner to form an original image on a photosensitive drum. At this time, the scanner is scanned from a point A to a point C as a prescan and standard white 13 is compared with the image density of each page of the book to read proper density. Then the scanner is returned to the point A after the prescan to start an A scan. Then, the scanner is moved with the quantity of exposure corresponding to the proper image density of the surface A of the book to perform exposure. Similarly, the surface B of the book is exposed properly. Paper, on the other hand, is fed normally during the exposure of the surface A and fed during the exposure of the surface B so that the end of the form is aligned with the middle point D of the book. Thus, each divided original is exposed on the best condition, so the copying density is optimized all the time. |
