| 摘要 |
PURPOSE:To suppress the fluorescent lamp of an image forming device from being blackened due to preheating. CONSTITUTION:A transformer 35 dedicated to preheating for feeding a high-frequency current to preheat filaments 11, 12 is provided separately from an inverter transformer 3 generating a tube current when a fluorescent lamp 1 is lighted. Transistors 32, 33 selectively controlling the high-frequency pulse for inputting the preheat signal pulse from the microcomputer of a control device to a transistor 31, controlling the preheating power of an oscillator 36 into the half preheat state and the full preheat state, and turning the connection to a driving power source on or off are operated on the primary side of the transformer 35. The high-frequency pulse is inputted to the primary side of the transformer 35 via an electrolytic capacitor 34 connected in series to drive it. |
