| 摘要 |
PURPOSE:To prevent generation of a black stripe in an image dune to decrease of light quantity of an exposure lamp without requiring a large battery capacity even when lowering of a power source voltage is caused by a power failure and the like. CONSTITUTION:In a copying machine provided with a lamp regulator 17 for feeding a lamp voltage to an exposure lamp based on an AC power source, an uninterruptive power supply 51 for back-up is Juxtaposed with an output side of the lamp regulator 17. The power supply 51 is provided with a battery 52 whose charging voltage is set lower than an ordinary output voltage of the lamp regulator 17 and which is charged based on an AC power source. With this constitution, when a power source voltage is lowered to a specified voltage or lower due to a power failure and the like to decrease an output voltage of the lamp regulator 17, power is supplied by the battery 52 of the uninterruptive power supply 51 in place of the lamp regulator 17 so that light quantity of the lamp is not lowered and lighting is maintained. |
