PURPOSE: To enable radiation of far infrared rays in great quantity with a shorter rise time while radiating no visible light in a infrared lamp used for printing toner in an electronic copying machine.
CONSTITUTION: A bulb 1 is made up of an infrared ray permeable heatproof material. An inert gas is sealed in the bulb and filament 2 is extended along the axis of thereof. Both ends of the filament are connected to internal lead-in wires 4 sealed in a crushed sealed section 3 at both ends of the bulb 1 and the lead-in wires are connected to external lead wires 6 through a conductive metal foil 5 sealed into the sealed section 3. In addition, a plurality of ring anchors 7 are mounted on the intermediate section of the filament 2 at a given spacing. The inner surface of the bulb is coated with a light absorbing film 8 formed by evaporating tungsten identical to the high quality filament 2 in material. With such an arrangement, the film 8 absorbs light projected from the filament to achieve the purpose.
KAMIO NOBUYUKI
WATANABE TSUTOMU
