| 摘要 |
PURPOSE:To prolong a span of service life in a headlight as well as to make the light possible to glow up immediately after lighting, by setting up a small discharge lamp and an incandescent lamp inside a single lighting device together with each of their reflector surfaces, while constituting the device so as to light the incandescent lamp till the discharge lamp glows stably. CONSTITUTION:With a glow starter switch 31 turned on, a control circuit 32 comes on whereby symmetrical metal halide lamps 7 and symmetrical tungsten halogen lamps 15 are all lighted via paired starting circuits 14. With this method, a shortage of light quantity in these metal halide lamps 7 is compensated with the light quantity of the tungsten halogen lamps 15. Therefore, the light quantity capable of starting a lamp can be secured even after lighting. After the elapse of time for lighting stability in these metal halide lamps 7, a timer 35 is set in motion, cutting off a continuous rating current for these tungsten halogen lamps 15 and turning off the tungsten halogen lamps 15. With this constitution, a span of service life in the tungsten halogen lamp can be prolonged, thus greater longevity as a headlight is well promoted. |
