| 摘要 |
PURPOSE:To prevent picture defective even if a photoreceptor has large light hysteresis, by varying blank exposure in proportion to picture exposure. CONSTITUTION:Through the operation of plunger 10, reflector 11 moves to the solid-line position, and then part of light from light source 1 is reflected by reflector 11 to perform the blank exposure of photoreceptor 6 via the same path with picture exposure as shown by the dotted lines. An adjustment of initial proper exposure to the variance in sensitivity of photoreceptor 6 and an adjustment corresponding to fluctuations of sensitivity are made through exposure aperture 7 of in-mirror lens 8 as usual. In this case, since the blank exposure is performed via the same path with the picture exposure, varying the quantity of the picture exposure via aperture 7 varies the blank exposure in proportion to it. Therefore, there is not need to set the blank exposure much greater than the exposure of a picture light part like the conventional method. |
