| 摘要 |
A lamp (1) according to an embodiment includes: a bulb (2), a filament (3), gas (4), and a multilayer film (5). The filament (3) is arranged on an inside (2a) of the bulb (2) along a tube axis. The gas (4) is filled in the inside (2a) of the bulb (2). The multilayer film (5) is formed on an outer surface (2b) of the bulb (2). Average visible ray transmittance at a wavelength of 380 nm to 780 nm of the multilayer film (5) is equal to or lower than 24%. In the filament (3), a plurality of projecting sections (31a) projecting toward an inner wall (2c) of the bulb (2) when viewed from the tube axis direction are formed in the circumferential direction and along the tube axis direction. |
