| 摘要 |
When electromagnetic waves containing infrared rays are released from a filament (41), the infrared rays are transmitted through an inner tube (42), the infrared rays reach a reflecting layer (46) provided at a distance from the inner tube (42) so as to cover only a part of the surroundings of the filament (41), and the infrared rays are reflected. At this time, the reflecting layer (46) is provided at a distance from the inner tube (42), and the reflecting layer (46) can be cooled by a coolant flowing through a coolant channel (49). It is thereby possible to suppress overheating of the reflecting layer (46) by a greater extent than when, e.g., the reflecting layer (46) is formed on the inner tube (42). A first outer tube (44) capable of transmitting infrared rays is provided between the inner tube (42) and the reflecting layer (46). The inner tube (42) and the first outer tube (44) are thereby present between the filament (41) and the reflecting layer (46), and overheating of the reflecting layer (46) can therefore be further suppressed. |
