METAL HALIDE LAMP AND LIGHTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a metal halide lamp improved in a luminous flux maintenance rate by restraining an airtight vessel from being blackened by dispersal of an electrode substance by regulating sizes of the airtight vessel and an electrode without any additional structure; and to provide a lighting system using it. SOLUTION: This metal halide lamp consists of: the fire-resistant and translucent airtight vessel 1 having an inside volume≤0.05 cc and having a surrounding part 1a with a length L of 6.5±0.2 mm; a pair of electrodes 1b, 1b enclosed in the airtight vessel 1 by facing to each other at an inter-electrode distance of 4.2±0.3 mm and each having a shaft diameter of 0.3-0.4 mm; and a discharge medium containing a metal halide containing a luminescent metal and Xe of 5 atmospheres at 25°C and enclosed in the airtight vessel 1 without substantially containing mercury. The tube wall load thereof is≥50 W/cm2in a stable time. COPYRIGHT: (C)2005,JPO&NCIPI