Optical scanning apparatus for detecting faults in transparent material wherein the plane of incident light is arranged at the breuster angle to the normal to the surface

摘要

An optical scanning apparatus for transparent, substantially flat material comprises a light source (21) and a mirror wheel (22) illuminated by the light beam. The mirror wheel generates a scanning beam which executes a periodic scanning movement in a scanning plane extending obliquely to the surface of the material. The scanning beam generates a scanning light bead on the surface of the material with the scanning light bead moving along a scanning line. A photoelectric light receiving device is arranged at the angle of reflection. The plane of incidence (11) is arranged at the Brewster angle relative to the normal (12) to the surface of the material (13) The light of the scanning beam (14) which executes the periodic scanning movement in the scanning plane (11) is linearly polarized parallel to the surface of the material or perpendicular to the scanning plane (11).