Efficient illumination system
AssigneeInternational Business Machines Corporation
InventorRandall Adrian Maddox
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Abstract
An illumination system of particular use in document copiers wherein an incandescent lamp which may be of the tungsten-halogen type is located at the focal point of a reflector shaped as a conic section such as elliptical cylinder, directing light rays toward an interference filter for separating the IR radiation and redirecting the IR rays back to the incandescent lamp for heating the lamp. Both cold mirror and hot mirror embodiments of the system are disclosed.
Claims18
An illumination system including an incandescent light source with a filament and bulb wall and including means for separating the visible light spectrum from the infrared spectrum and redirecting a substantial portion of said infrared spectrum to the light source, comprising:
- a reflector means for reflecting both the infrared and visible spectrum, said reflecting means shaped into a conic section with a focal point, said light source located at the focal point of said reflector means;
- a filter means for separating said visible light from said infrared light, said filter means receiving rays from said reflector means;
- and
- infrared reflecting means receiving rays from said filter means for reflecting at least a substantial portion of said infrared spectrum back upon said light source,
- whereby said filament and bulb wall are heated by the infrared radiation.
Dependencies are inferred from the claim text.