| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a metal halide lamp with satisfactory performance as a substitute light source of a mercury lamp through effective prevention of overheating of a lighting circuit. <P>SOLUTION: The metal halide lamp includes: a double-tube structure 42 consisting of an arc tube 44 with halogenated metal sealed as light-emitting substance and an inner tube 46 airtightly sealing the arc tube 44; an outer tube 16 containing the double-tube structure 42; a cylindrical case part 102, jointed to an open end part of the outer tube 16, for supporting the outer tube 16; and a lighting circuit unit 18, contained in the case part 102, for lighting the arc tube 44. An outer tube retention part 104 as a part of the case part 12 at least supporting the outer tube 16 is to be formed of a material with thermal conductivity of 1.0[W/(mK)] or lower over a whole periphery direction. <P>COPYRIGHT: (C)2011,JPO&INPIT |
