| 摘要 |
PURPOSE:To control exposure to form a good image at the restart of copying after suspension, by storing charging characteristics at the preceding operation. CONSTITUTION:The charged potentials of a photosensitive drum 1 surface on the light part illuminated with an original exposure lamp 4 or an unillustrated blank exposure lamp and on the part not illuminated are measured with a potential sensor 8. The voltage sources 18, 19 of chargers 5, 6 are controlled in accordance with the weighted average of the 2 values. The potential of the light part is remeasured to control the voltage source 21 of the lamp 4. A developing bias voltage source 20 is likewise controlled. On the other hand, the time length of suspending charging and that of continuing charging are measured, and rise of the lamp 4 and decay are controlled in accordance with the result, but a coefficient to be used for control is corrected on the basis of the stored dark part charging characteristics at the preceding operation. |
