| 摘要 |
PROBLEM TO BE SOLVED: To provide a mercury-free metal halide discharge lamp stably lit so as to correct discharge arc almost linearly against gravitational guidance convection with the use of acoustic resonance phenomenon, and a metal halide discharge lamp system lighting the same. SOLUTION: The metal halide discharge lamp MHL is provided with an airtight vessel 1 of corrosion resistance and translucency of a maximum inner diameter of 2.0 to 12.0 mm, a pair of electrodes 2A, 2B, and a discharge medium sealed in the airtight vessel containing halide and rare gas and not substantially containing mercury. It is so structured that the discharge arc is stably straightened even if a current is made to flow in the airtight vessel to light it with a ripple current superposed of either a given frequency within the range of a first frequency f1 relatively low satisfying formula [1] (unit: kHz) or a given frequency within the range a second frequency f2 relatively high satisfying formula [2] (unit:kHz). Here, the formula [1] is expressed by: 70≤f1≤130, and the formula [2] by:120≤f2≤260. COPYRIGHT: (C)2007,JPO&INPIT |
