Patent ID: 8279441
Filing Date: 2012-10-02
Classification: G01J

Abstract:
1. In a spectrophotometer having a light source to be directed upon a reflective sample for measuring the spectral reflectance of a sample surface, an improved light source comprising: (a) a plurality of LEDs arranged in an array and mounted in a bracket having apertures each corresponding to a different one of said LEDs; (b) a corresponding plurality of electrofluorescent illuminants each corresponding to a different one of said LEDs and each positioned on a different one of said apertures to intercept emitted light energy from a corresponding different one of said LEDs and re-emit light energy at a different wavelength; (c) the light energy re-emitted by each electrofluorescent illuminant having a predetermined spectral bandwidth and a different center wave length and wherein the predetermined spectral bandwidths of each of electro-fluorescent illuminant, when combined with the spectral bandwidths of other electro-fluorescent illuminates produces white light; and (d) each of said LED being individually adjustably energized by a pulse width modulated signal.