An incandescent lamp and a lighting apparatus using the lamp

摘要

An incandescent lamp has an envelope (1) having a bulbous portion (4) including a wall defining a space, a thin tube (5) extending outwardly along a central axis (O1-O1) of the bulbous portion (4) so as to communicate with the space, and a sealed portion (2) located on an opposite side to the thin tube (5). The wall has a slope (7) being inclined to the thin tube (5) near the thin tube. A filament (13) is provided along said central axis of the bulbous portion (4) for generating heat during lamp operation. An optical interference layer (6) is arranged on a surface of the wall for reflecting infrared rays toward the filament (13). A first lead wire (9) has a first end portion (9a) fixed in the sealed portion (2) of the envelope, a second end portion (9b) coupled to one end of the filament (13) and an intermediate U-shaped portion (8) inserted into the thin tube (5) for regulating the position of the lead wire. A second lead wire (12) has a first end portion (12a) fixed in the sealed portion (2) of the envelope and a second end portion (12b) coupled to other end of the filament. <IMAGE>