Incandescent lamp with infrared reflecting-visible energy transmitting coating and misaligned filament

摘要

An incandescent electric lamp having an envelope and means for reflecting infrared energy back to the filament to increase its operating temperature while transmitting visible energy. The envelope is shaped to reflect the infrared energy back to the filament and the filament is purposely misaligned with respect to the optical center of the envelope so that the infrared energy impinges on the filament after two reflections from the envelope wall.