| 摘要 |
PURPOSE:To compensate sensitivity deterioration of a photosensitive body by detecting a grid current of an electrification device, and automatically adjusting an exposure quantity and/or development bias voltage according to the current. CONSTITUTION:A light quantity of an exposure lamp 35 is adjusted according to a grid current of an electrification charger 20. That is, a photosensitive body keeps its initial conditional when the outputs of comparators 11 and 12 are low and high respectively, consequently the drive voltage of the lamp 35 is set to V1 (a light tone circuit 33 is controlled via a resistance r11). The sensitivity of the photosensitive body is deteriorated in a certain extent when the outputs of the comparators 11 and 12 are low and the output of a comparator 13 is high, consequently voltage is set to V2 to increase the light quantity (the circuit 33 is controlled via a resistance r12). The sensitivity is considerably deteriorated when the outputs of the comparators 11 - 13 are low and the output of a comparator 14 is high, consequently voltage is set to V3 to more increase the light quantity (the circuit 33 is controlled via a resistance r13). By the way, development bias voltage can be also adjusted. |
