Incandescent lamp with high pressure rare gas filled tungsten-halogen element and transparent thick walled safety envelope

摘要

An incandescent lamp unit in which a light emitting element of the tungsten-halogen type is placed within an outer, safety protecting transparent envelope. The element, being protected by the outer envelope, is filled with a gas at a high pressure, thereby increasing its efficiency, and the space between the element and the outer envelope is also preferably filled with a gas having good heat conductivity properties. The outer envelope also can have a coating of a material which transmits visible range energy and reflects infrared energy.