| 摘要 |
PURPOSE:To save the energy of the whole copying machine by securing color reproducibility only when a color document is copied and fully using the performance of a light source and an image formation medium when a monochromatic document, which is an absolute majority of ordinary documents, is copied. CONSTITUTION:A color CCD 7 or photodetecting element 11 detects the color document at the time of prescanning and a color document decision means 8 which is connected thereto discriminates between the color document and monochromatic document, and when the color document is decided, an infrared- light cutting filter 12 is put in an optical path, but when the monochromatic document is decided, a light source 2 for exposure is decreased in the quantity of exposure and the infrared-light cutting filter 12 is put off the optical path. |
