| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a high-watt type ceramic metal halide lamp capable of increasing the lamp life while maintaining high light emission efficiency.SOLUTION: The high-watt type ceramic metal halide lamp comprises a luminous tube in which at least mercury and a metal halide are filled, and the luminous tube includes a thick tube part and a pair of thin tube parts which are formed in both ends of the thick tube part. With respect to an inner diameter L6 of the thin tube part, an outer diameter L14 of a metallic coil bar is settled within a range of 0.96≤L14/L6≤0.98, and a space between the thin tube part and a current introduction body is divided into a sealed region and a non-sealed region. A cavity GA in the non-sealed region is in a range of 5.0 mm≤GA≤17.5 mm. An outside diameter of a conductive cermet bar is in a range from 1.7 mm to 0.87 times of the L6.</p> |
