| 摘要 |
PURPOSE:To eliminate wasteful electric power and to prevent the life of a fluorescent lamp from shortening by adding the maximum voltage until the light quantity of the fluorescent lamp reaches a specified value after turning on a power source, and switching the voltage to a low level when the light quantity detected by a detector reaches a specified value. CONSTITUTION:The power source is turned on and the voltage of the maximum level is applied on the fluorescent lamp 3, and the light quantity increases nearly in proportion to time. When the light quantity reaches the specified value,a sensor 34 detects it and a copying OK signal is outputted, then a pilot lamp is lighted. At the same time, a voltage level signal is switched to a preheat voltage level for maintaining the light quantity. The temp. of the tube wall of the fluorescent lamp 3 is kept nearly constant with the preheat voltage. When a printing key is turned on, a lighting signal is outputted and also the voltage level signal according to the exposure setting volume is outputted. Then, distinct copying can be executed without waiting, and wasteful application of voltage and short of the life of the fluorescent lamp can be prevented. |
