Patent ID: 7408145
Filing Date: 2008-08-05
Classification: G01J,G01N

Abstract:
1. A light sensor for measuring the reflectance of an object, comprising: (a) a polychromatic light source simultaneously emitting visible light and infrared light with a modulator of the light source, and apparatus to set and monitor optical power of the light source; (b) a reflected light receiver comprised of an array of photodetectors comprised of at least one photodetector sensitive to visible light positioned to receive reflected light originating from the light source and including ambient light compensation means for reducing the effects of ambient light on the photodetector and a first output, and at least one photodetector sensitive to nonvisible light positioned to receive reflected light originating from said light source and including an ambient light compensator for reducing the effects of ambient light on said second photodetector and a second output; (c) a detector for distinguishing the light originating from the light source and light reflected by the object from ambient light; and (d) a computational device for performing calculations based on reading the first output, reading the second output and the light source power.