Patent ID: 8947660
Filing Date: 2015-02-03
Classification: G01J,G01N

Abstract:
1. A method for carrying out an optical comparison of first and second two dimensional samples, each of which is patterned such that the first and second samples are not evenly colored, comprising: illuminating a portion of the first sample with scattered light, and guiding light reflected from the portion of the first sample through an optical wavelength separating device onto an imaging camera; utilizing an output of the imaging camera to generate a first spectrum for the first sample that includes light amplitude values at a plurality of different wavelengths; generating an image of the portion of the first sample with a position detection camera; storing the image of the portion of the first sample with information regarding the first spectrum; illuminating a corresponding portion of the second sample with scattered light, and guiding light reflected from the corresponding portion of the second sample through the optical wavelength separating device onto the imaging camera, wherein the portion of the first sample and the corresponding portion of the second sample have substantially identical patterns; utilizing an output of the imaging camera to generate a second spectrum for the second sample that includes light amplitude values at a plurality of different wavelengths; and comparing the first and second spectrums, or values derived from the first and second spectrums, to determine a degree of similarity between the first and second samples.