Patent ID: 6111650
Filing Date: 2000-08-29
Classification: G01J

Abstract:
An apparatus for color matching of slightly colored translucent objects, using diffuse spectroscopy, said apparatus comprising:a source of polychromatic light;a first set of optical fibers having a first end connected to said source of polychromatic light and a second end connected to a handpiece so as to pass light to said objects;a second set of optical fibers having a first end connected to a spectrometer and a second end connected to said handpiece, wherein said second set of optical fibers collects diffuse light scattered from said objects;a third set of optical fibers connecting said source of polychromatic light to said spectrometer;said spectrometer comprising a first measuring part having a measuring spectroscopic unit and measuring photo detectors at an outlet and a reference part having a reference spectroscopic unit and reference photo detectors at an outlet;wherein said measuring and reference photo detectors are connected to a microprocessor system programed to determine, on the basis of output from said photo detectors, a pigmentation value of the objects as a function of a difference in reflectance measured between red and blue spectral components of said objects and brightness of said objects as defined by reflectance measured at a green spectral component of said objects, as measured relative to a standard reference source;said microprocessor system further programed to determine, on the basis of said brightness and pigmentation values, a standard shade material corresponding to said translucent objects.