| 摘要 |
PURPOSE:To stabilize picture quality and to prolong the service life of a photosensitive drum by charging the photosensitive drum electrostatically with a proper quantity of light after original exposure. CONSTITUTION:A signal voltage for exposure is applied between terminals 32 and 34 and a photocoupler 28 turns on. A voltage which is adjusted by a variable resistor 26 is applied to a halogen lamp 4 by a triac 21, and the halogen lamp 4 irradiates an original for exposure and also irradiates the photosensitive drum through a reflecting plate to perform electrostatic discharging. The signal voltage applied between the terminals 32 and 34 is ceased after the end of the original exposure and a voltage is applied between terminals 33 and 34. Consequently, a photocoupler 29 turns on and a voltage set by a variable resistor 27 is applied to the halogen lamp 4 by the triac 21. Consequently, the photosensitive drum after transfer is charged electrostatically by the halogen lamp 4 which is adjusted to a smaller quantity of light than that in the exposure. |
