| 摘要 |
PROBLEM TO BE SOLVED: To provide an incandescent lamp including a filament which converts power into visible light with high efficiency.SOLUTION: The incandescent lamp has a translucent airtight container, a filament arranged in the translucent airtight container, and a lead wire for supplying a current to the filament. The filament includes a substrate composed of a first metal material, and a metal film composed of a second metal material and covering at least a part of the substrate. The second metal material composing a metal film has a melting point lower than that of the first metal material composing the substrate. Since light of large energy (visible light) can be radiated by bremsstrahlung of a metal film having a melting point lower than that of the substrate, an incandescent lamp having a high visible light luminous flux efficiency can be obtained. |
