COMPACT-TYPE FLUORESCENT LAMP

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 and igniting the emission tube by an alternating current so that said electrode works 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 current 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 to cause an asymmetric discharge current to flow. 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 a homogeneous luminous state over the entire emission tube 1'.