| 摘要 |
PROBLEM TO BE SOLVED: To provide a metal halide lamp lighting system of vertical lighting form capable of improving lamp efficiency even in the case of small added quantity of sodium. SOLUTION: The metal halide lamp lighting system is provided with a metal halide lamp 5 which houses in an outer bulb 8 a ceramic arc tube 7 which has a pair of electrodes and into which a metal halide containing sodium is filled, a lighting device 20 which gives rectangular lamp current to the metal halide lamp and lights it, and a support equipment to support the metal halide lamp in vertical direction. This lighting device 20 lights the metal halide lamp 5 by superposing a direct current component on the rectangular lamp current so that DC bias may be impressed on the lower side electrode of the arc tube 7 of the metal halide lamp supported in vertical direction. COPYRIGHT: (C)2008,JPO&INPIT |
