Patent ID: 8736168

Claim:
In a ceramic metal halide lamp including a luminous tube in the interior of an outer bulb, said ceramic metal halide lamp is characterized in that: said luminous tube is made from translucent ceramics and is formed of a light-emitting portion into which metal halides, mercury and a starting gas are sealed and capillaries with a pair of electrode assemblies extended thereto disposed at both ends of said light-emitting portion; said light-emitting portion has sealed therein at least halides of rare earth metal, halide of thallium (Tl), halide of sodium (Na) and halide of calcium (Ca); and said light-emitting portion has further sealed therein halide of silver (Ag); wherein a quantity of silver sealed into said light-emitting portion falls within a range of 2≦(Ag/Ca)[molar ratio]≦5 and within a range of 0<(Ag/Tl)[molar ratio]≦10.