| 摘要 |
PURPOSE:To prevent the illumination of a lighting device from being entirely suppressed by installing a discharge gap, which maintains discharge until a high- pressure discharge tube starts working agin, and the high-pressure discharge tube having a light color similar to that of a white bulb, which connected parallel to the discharge gap, in an outer tube. CONSTITUTION:When the light of a high-pressure discharge tube 4 is suppressed by a temporary drop of source voltage or the like, the tube 4 cannot be lit after normal source voltage is restored. However, the application of source voltage enables a discharge gap 8 to perate, and the discharge gap 8 and a tungsten filament 7 discharge light during the time when the light of the high-pressure discharge tube 4 is suppressed. Thus a discharge lamp continues to discharge light according to the emission sacrifice of both the discharge gap 8 and the tungsten filament 7, and the light of the discharge lamp is not entirely suppressed. When the temperature of the high-pressure discharge tube 4 is reduced and the vapor pressure within the tube 4 is decreased with the discharge gap 8 burning, discharge within the tube 4 is initiated again. |
