| 摘要 |
PURPOSE:To reduce the time required for chromaticity points to enter the white range so as to enhance safety by forming a phosphor film over the inner surface of an outer tube having a light emitting tube which has a pair of electrodes, a metal halide, and a rare gas sealed therein. CONSTITUTION:An automobile headlight metal halide lamp has a light emitting tube 1 having a pair of electrodes 1a, 1b provided therein and mercury, a metal halide and a rare gas sealed therein. One end portion of the light emitting tube 1 is supported to a base 2 made from a synthetic resin such as PSC, and an outer tube 3 is secured to the base 2 and a phosphor film 4 made from trivalent europium-activated yttrium-vanadium phosphor is formed along the overall length of the inner surface of the outer tube 3. Therefore, at startup the film 4 can be made to emit light of the visible range when receiving light of the ultraviolet range emitted by the mercury, so that light from the mercury can be supplemented until stability is achieved. Therefore, changes in chromaticity point and color rendering property are minimized and the time required for reaching the white range is shortened, so that safety can be enhanced. |
