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(11) | EP 0 470 496 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Incandescent lamp and reflector type projection lamp |
(57) reflector type projection lamp comprising an incandescent lamp (1) provided on the
inner or outer surface of its bulb (2) with an interference layer for reflecting infrared
light and transmitting visible light and a reflector (10) provided on its reflecting
surface with an interference layer (15) for reflecting visible light and transmitting
infrared light is characterized in that the bulb (2) of said incandescent lamp is
either spherical or spheroidal. Of the light emitted from the filament (6) of the
incandescent lamp, the infrared component is effectively reflected by an interference
layer (9) on the bulb and returned to the filament to enhance the overall lighting
efficiency of the lamp and reduce the rate of heat irradiated from the lamp into the
atmosphere. |