METAL HALIDE LAMP, AND LIGHTING APPARATUS USING THE SAME

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PROBLEM TO BE SOLVED : To provide a metal halide lamp of which a container is made of ceramic of polycrystal alumina, in which short lifetime is prevented without applying a special treatment, even if the ceramic contains lanthanum. SOLUTION : The metal halide lamp has a container 12 made of ceramic consisting of polycrystal alumina, and has an electrode body 21 arranged inside, and is provided with an arc tube 4 containing at least one kind of rare earth metal out of dysprosium (Dy), thuliumn (Tm), and holmium (Ho) as a light-emitting substance. The composition ratio of the total rare earth metal to the total light-emitting substance (provided that mercury is excluded) is 5 [mol%] or more and 35 [mol%] or less, and the content of lanthanum (La) contained in the ceramic constituting the container 12 is 100 [ppm] or more and 300 [ppm] or less. COPYRIGHT : (C)2009, JPO&INPIT