| 摘要 |
PROBLEM TO BE SOLVED: To provide a metal halide lamp with start-up voltage lowered and not sealing mercury as well as a lighting fixture using the same. SOLUTION: The metal halide lamp is provided with an airtight vessel equipped with an envelope part 1a with a maximum inner diameter of D mm, a pair of electrodes 1b sealed in opposition inside the same with an interval of L mm, and a discharge medium consisting of rare gas containing a chemical and Xe by 5 to 30 mg/cc to an inner volume of the envelope part 1a with a charged pressure of 8 atm. at 25°C not intrinsically containing mercury. When a formula 1 (0.11<d/L<0.24) and a formula 2 (D≥2d+0.7) are satisfied, provided, a shortest distance from a tip of the electrode to an inner face of the envelope part 1a at at least one of the electrodes 1b is d mm, and at the same time, and when a high-voltage pulse with a rising time of a voltage waveform of 60 to 500 ns at a part where an instantaneous value is 10 to 90% of a wave height value is impressed between the pair of electrodes, the lamp gets started. COPYRIGHT: (C)2005,JPO&NCIPI |
