Energy-efficient incandescent reflector lamp
AssigneeDuro-Test Corporation
InventorPeter J. Walsh
Life of this patent
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Abstract
An incandescent lamp of the reflector type has an exit window on which a filter coating is located. The filter coating reflects infrared radiation and transmits visible radiation. The clamp also has a reflector which is opposed to the filter coating and which reflects both infrared and visible radiation. The filter coating and the reflector have surfaces which are parabolic, confocal, and orthogonal. The filament passes through the focus and is elongated along the focal axis of the lamp. Infrared radiation emitted by the filament from the focus is reflectd back to it after two reflections, of which one reflection will be off the filter coating and of which the other will be off the reflector. A large part of the light produced by the lamp is collimated.
Claims21
An energy-efficient incandescent lamp, comprising:
- a hollow envelope having an exit window with an infrared reflecting and visible transmitting filter coating thereon, the exit window on which said filter coating is located having a parabolic first surface which faces the interior of the envelope with a first focal length, a focus, and a focal axis,
- reflector means reflective to both infrared and visible energy having a parabolic second surface, a second focal length, a focus and a focal axis, said focus of said second surface being located inside the envelope, the focal axis of each of said first and second surfaces being coaxial and the focus of each said parabolic surface being confocal;
- and
- a filament located inside the envelope for producing energy both in the infrared and visible ranges, the filament being at least in part on said confocal foci of said surface, the infrared energy produced by said filament being reflected at least in part by said first and second surfaces back to said filament to raise its operating temperature and the visible range energy being reflected from said second surface for exiting through said exit window in a substantially collimated beam.
Dependencies are inferred from the claim text.