| 摘要 |
PURPOSE:To prevent brightness appearing around the electric poles from making irregular variation by pinching a filament coil with two lead wires, and setting the electric poles with their filament coil terminal portions outside the lead wires bent to the discharging sides. CONSTITUTION:Filament 1 with its double coiled portion (a) to which an oxide is applied on almost all the surface is pinched with lead wires 2, 2', filament terminal portions b, b', outside the lead wires 2, 2', are bent almost perpendicularly to the discharging sides. Here, the tips of the filament terminals b, b' are projected enough to the discharging sides beyond the top portions C, C' of the lead wires 2, 2' and the secondary coil portion (a) of the filament 2. With this constitution, a lamp is prevented from flickering for a long period of lighting. This is due to the fact that fluctuation in electron current distribution does not take place, even though the exposed surface of the metal portion of the filament is increased through gradual consumption of the oxide of the electrode, based on the charactristics that thwn the pole is positive, electrons steadily flow onto the projecting end of a filament. |
