摘要 |
PROBLEM TO BE SOLVED: To light a ceramic metal-halide lamp while stabilizing arc from initial stage of lighting even if cerium iodide is added to an arc tube as a metal halide. SOLUTION: An arc tube (1) where a light-emitting part (2) and capillaries (3A, 3B) to which a pair of electrode assemblies (6A, 6B) arranged at the opposite ends thereof is inserted are formed of translucent ceramic is contained in a translucent outer tube (10), and cerium iodide is added as a metal halide. In such a ceramic metal-halide lamp (L), a closed-loop arc tube supporting frame (F) equipped with two parallel posts (12R, 12L) extending in the longitudinal direction from the proximal end (10A) side where a base (11) is formed to the distal end (10B) side is fixed by welding to a stem lead (18b) receiving power supply through the base (11), in the outer tube (10). At least a part of one parallel post corresponding to the position of the light-emitting part (2) of the arc tube (1) is constituted of a non-conductive member (23). COPYRIGHT: (C)2012,JPO&INPIT |