| 摘要 |
PURPOSE:To obtain a light compact-type fluorescent lamp of a relatively low cost by providing the emission tube with an area located near one of the electrodes and spatially connected to an outer tube globe, igniting the emission tube by an asymmetrical alternating current having a d.c. component and causing said electrode to work as an anode in terms of its d.c. component. CONSTITUTION:An emission tube 1' consisting of a so-called double-U-shaped tube has an area 13 which is located near an electrode 4 and spatially connected to an outer tube globe 3. The emission tube 1' is ignited by a chopper-system high-frequency ignition circuit in which chopper operation is repeated by the combined function of a power transistor 17, a choke coil 21, a capacitor 22 and a diode 23. During the ignition of the emission tube 1', the electrode coil 4 located near the connection area 13 works as an anode in terms of its d.c. component. Owing to the above constitution, any cataphoresis is completely prevented, thereby producing over the entire emission tube 1' a homogeneous luminous state almost the same as that produced when the emission tube 1' is ignited by a conventional alternating current having no d.c. components. |
