| 摘要 |
PURPOSE:To improve the characteristic in a low temperature, to miniaturize an image forming device, and to reduce cost by detecting the ambient temperature of a fluorescent lamp, and controlling both the discharging light of the lamp and energizing heat of each electrode filament. CONSTITUTION:In switching on the fluorescent lamp 2, the electrode filaments 2(a) and 2(b) of the fluorescent lamp 2 is lit on simultaneously when its ambient temperature is lower than a set value, thereby raising the ambient temperature quickly: the device is constituted in such a way that the illuminance of the fluorescent lamp 2 is immediately raised to the target value. Therefore, the fluorescent lamp 2 does not need any flat external heating element; the life of the lamp 2 is not shortened since the electrodes filaments 2(a) and 2(b) are not lit when the lamp 2 is not lit; and it is not necessary to provide the device with a means emitting a sufficient amount of light even at a low temperature. Consequently, the device is miniaturized and the cost is reduced. |
