| 摘要 |
PROBLEM TO BE SOLVED: To provide a light source device provided with a filament having high efficiency in converting electric power into visible light.SOLUTION: There is provided the light source device having a translucent airtight container, a filament disposed in the translucent airtight container, and a lead wire for supplying a current to the filament. The filament has a base constituted of a metal material, a white scatterer layer covering the base, and an infrared light reflection auxiliary layer for enhancing infrared light reflection on the surface of the filament. A visible light absorbing material which absorbs light in a visible light region is added to the white scatterer layer. Thus, since the reflectance of visible light is made lower and the reflectance of infrared light is made higher, radiation of infrared light is suppressed to allow an increase in luminous flux efficiency of visible light. |
