METHOD FOR EVALUATING FRESNEL DIFFRACTION BORDER PROFILES

摘要

A method for determining the position of at least one edge of an object, in particular a strand, comprises illuminating the object using light from at least one coherent light source, wherein diffraction borders are generated on both geometric boundaries of the shadow caused by the object. The method also includes recording the spatial intensity profile of at least one diffraction border using at least one single or multi line optical sensor, differentiating the at least one recorded intensity profile with respect to location and plotting it using a squared location axis, and comparing the at least one recorded intensity profile, differentiated with respect to location and plotted using a squared location axis, to at least one periodic reference intensity profile. The position of at least one edge of the object is determined on the basis of the completed comparison.

主权项

1. A method, comprising:
illuminating an object using light from at least one coherent light source, wherein diffraction borders (22) are generated on geometric boundaries of a shadow caused by the object; recording a spatial intensity profile of at least one of the diffraction borders using at least one single or multi line optical sensor; differentiating the at spatial intensity profile with respect to location and plotting it over a squared location axis; comparing the spatial intensity profile, differentiated with respect to location and plotted over the squared location axis, to at least one periodic reference intensity profile; and determining a position of at least one edge of the object on the basis of the comparing.