| 摘要 |
PURPOSE:To reduce wastage of getter metal by mounting the mercury getter serving to absorb mercury in turning off the captioned lamp and discharge it in starting the lamp in the vicinity of an electrode of a luminous tube, while providing an auxiliary electrode located on the side of a discharge space from the mercury getter. CONSTITUTION:The captioned low pressure mercury vapor electrical discharge lamp is formed by housing a double U-shaped fluorescent lamp 5 having electrodes disposed on both ends thereof, a glow switch 6, and a ballast stabi lizer 7. Thereupon, a mercury getter 20 yielded by depositing indium on both surfaces of a stainless metal gauge is mounted in the vicinity of the electrode 17 after welding it to a lead wire 16, whereby the mercury getter is adapted to adsorb mercury upon turning off the lamp while it adapted to discharge mercury upon starting the lamp. While, an auxiliary electrode 23 having the lead wire 16 formed thereon by extending the wire is provided located on the side of a discharge space from the mercury getter 20. Hereby, the ions in con cern is adsorbed onto the auxiliary electrode 23 upon starting the lamp to moderate collision of the ions to the mercury getter 20, whereby wastage of the getter metal is reduced to improve the life of the lamp. |
