| 摘要 |
<p>This mercury-free metal halide lamp for vehicles is equipped with a sealed vessel (1) including a light-emitting part (11) that has a discharge space (111) inside, a metal halide (2) and a rare gas that have been confined in the discharge space (111), and a pair of electrodes (32) which have been disposed so that the ends of the respective electrodes (32) face each other in the discharge space (111), the electrodes (32) and the discharge space (111) containing no thorium. When the electric power supplied to the lamp that is in the state of stably shining is expressed by P (W), the integrated quantity of the electric power supplied to the lamp during the period from the time when one second has passed since switching on the lamp to the time when 40 seconds have passed since the switching on is expressed by WL (W), and the diameter of the electrodes (32) is expressed by D (mm), then P (W) and WL/D (W/mm) satisfy 20=P=30 and 4300=WL/D=7400, respectively. Thus, a mercury-free metal halide lamp for vehicles which can be inhibited from flickering or from suffering electrode deformation, needs less electric power than conventional lamps, and does not contain radioactive substances including thorium is provided.</p> |
