| 摘要 |
PURPOSE:To obtain a distinct image from the leading edge of copying, to prolong the life of a fluorescent lamp and to judge a fault before occurring by executing a previous lighting with a voltage according to the temperature of the tube wall of the fluorescent lamp, completing it when light quantity reaches a specified value and displaying the shortage of the light quantity when a previous lighting time exceeds a specified time. CONSTITUTION:When a power source is applied, the temperature of the tube wall of the fluorescent lamp 3 is detected by a temperature detector 35 and the previous lighting by a voltage according to the temperature is executed through an output variable type lighting device 27. When the light quantity detected by a light quantity detector 34 reaches the specified value, the previous lighting is completed and a copying-enable signal is outputted. Meanwhile, when the previous lighting time exceeds the specified time, the shortage of the light quantity is displayed. Thus, copying is executed with sufficient light quantity so as to obtain a clear image. Since the previous lighting is not executed for a specified time with voltage of the maximum level, the life of the fluorescent lamp can be prolonged. In case of the abnormality, etc., of the fluorescent lamp 3 the fault can be directly judged. |
