Patent ID: 6532065
Filing Date: 2003-03-11
Classification: G01N

Abstract:
A device for testing an object with an uneven or arbitrarily structured surface for impurities in the form of raised areas on the surface, comprising:at least one light source for producing at least one light beam comprising approximately parallel light which is directed at the surface of the object and sweeps over a region of the surface of the object; and a non-polarizing light sensor disposed in a plane that extends approximately perpendicular to the surface of the object, wherein incident impurities in the region of the surface of the object swept by said approximately parallel light cause a scattering of said at least one light beam, whereas those parts of the region free of incident impurities cause no change, or only a slight change, of said at least one light beam, and wherein at least a part of said at least one light beam scattered out of the region of the surface swept by said approximately parallel light is detectable by said light sensor.