| abstract |
Provided is a ceramic metal halide lamp that can achieve a correlated color temperature on the order of 2500 K without sacrificing lamp life. An additive contains Thallium iodide (TlI), Sodium iodide (NaI), Calcium iodide (CaI 2 ), Lithium iodide (LiI), and a rare earth metal iodide, and is further configured in a manner so that the correlated color temperature is 2250-2750 K, the bulb wall loading is 20-30 W/cm 2 , and the rated output is 35-400 W. When the mole ratio of Sodium iodide to the total number of moles of the additive is M(NaI) (in mol%) and the sum of the mole ratio of the rare earth metal iodide (ReI 3 ) and the mole ratio of Thallium iodide (TlI) is M(ReI 3 +TlI) (in mol%), 4 < M(NaI)/M(ReI 3 +TlI) < 16 and 2 mol% < M(ReI 3 +TlI) < 9 mol%. |