摘要 |
<p>An incandescent lamp having a coating thereon which returns infrared energy to the filament to decrease the amount of power consumed by the lamp in order to maintain the filament at a predetermined operating temperature has a predetermined fractional spacing between turns which results in an emissivity greater than 0.5 at 2,000.degree. K. The filament also has a predetermined length to diameter ratio to make it compact and thereby improve its emissivity and the capture of the reflected infrared radiation and to reduce aberration losses. The filament can be a coiled coil or triple coiled coil and can be stabilized by secondary recrystallization.</p> |