US Patent 7402952 Incandescent lamp with a carbon cycle and a halogen cycle

The incandescent lamp, which uses a carbon cycle process, is equipped with a luminous body which, together with a fill, is introduced in a vacuum-tight manner into a bulb, the luminous body including a metal carbide, the melting point of which is above that of tungsten. The distance between the luminous body and the wall of the bulb is less than 18 mm, with a first cycle process, which is attributed to the carbon, being effected by the use of carbon and hydrogen as fill additive, and a second cycle process, which is attributed to the metal, being effected by the use of halogen.