How it works, Inventors, Variations of design. This is an incandescent lamp which uses halogens like bromine and iodine to prevent the tungsten filament from degrading. It has a great color rendering and good efficiency compared with regular incandescents. Invented by Elmer Fridrich, Frederick Mosby at GE. Improved with bromine by Philips in the 1960s. Part of the Electric Light series by Edison Tech Center