| 摘要 |
PURPOSE:To adjust image density with high precision by finding the brightest reflection part of an original and updating a reference point from the point of time, and calibrating the reference value for every original. CONSTITUTION:When a copying machine is put in operation after an original 5 is placed on platen glass 3 and a platen cover 4 is closed, an exposure lamp 6 turns on to irradiate a reference reflecting plate 33. Its reflected light reaches a photodiode 28 through mirrors 9-11 and a lens 13. The quantity of reflected light is set in an arithmetic control circuit 29 as a reference light quantity value. Then, the lamp 6 and mirror 9 are moved to right and a drum type photosensitive body 14 is rotated in its opening direction. Simultaneously, the surface of the photosensitive body 14 is exposed to an image of the original 5, its latent image is developed by a developing device 17 to form a toner image, which is transferred to a form 25 by a transfer device 19 and fixed 27. The diode 28 is irradiated with part of the reflected light from the original 5 and its output is sent to a circuit 29 and compared with the reference light quantity value. |
