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US 5,477,322 AGranted
Spectrophotometer with light source in the form of a light emitting diode array
AssigneeNIRSystems Incorporated
InventorDonald R. Webster
Life of this patent
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AssigneeNIRSystems Incorporated
InventorDonald R. Webster
Estimating the term…
In a spectrophotometer, a light source is provided in the form of a multiplicity of light emitting diodes which transmit light through an entrance slit to irradiate an oscillating grating. The light is dispersed by the grating toward an exit slit which transmits a narrow bandwidth of light to irradiate a sample. As the grating oscillates, the wavelength transmitted through the exit slit is scanned through a selected spectrum. The diodes in the array each emit light in a different wavelength band so that the diodes as a group emit light throughout the selected spectrum. As the grating oscillates, the diodes are energized and extinguished in sequence so that no more than two diodes will be energized at any given instant of time and the energized diode will be emitting light at the wavelength dispersed by the grating to the exit slit.
A spectrophotometer comprising an optical grating, means defining an entrance slit for said grating, a multiplicity of light emitting diodes arranged to irradiate said grating through said entrance slit so that light from each of said light emitting diodes irradiates said grating from the same angular position defined by said entrance slit, an exit slit parallel to said entrance slit positioned to transmit a narrow wavelength band of light dispersed by said grating, means to rotate said grating to scan the wavelength of the light transmitted through said exit slit through a selected spectrum, said light emitting diodes each generating a different wavelength band selected so that the multiplicity of light emitting diodes as a group emit light with wavelengths extending over said spectrum.
Dependencies are inferred from the claim text.