| 摘要 |
PURPOSE:To discriminate on a copy easily by detecting an image processing condition with a pattern formed by using a reflection type liquid-crystal panel, and controlling image processing. CONSTITUTION:When copying operation starts after image display operation, an image displayed on liquid crystal is cleared temporarily, the potential on a photosensitive body 8 corresponding to a light part is measured by an electrometer 25, and the quantity of light of an exposure lamp 9 is increased until the light part potential reaches a specific potential. Then, the liquid-crystal is displayed entirely in black and the potential of a primary electrifier 7 is varied until the contrast between the light part and shade part potentials converges on a prescribed value. A reflecting plate 26 is attached to the reverse surface of a transmission type liquid-crystal display element 3. When said control is completed, the stored image is reproduced on the display screen 2 and copied to obtain a copy having clear contrast without any ground fogging. |
