Patent ID: 7538866

Claim:
An optical sensor for detecting punctiform, linear or laminar defects on smooth surfaces, comprising: a telecentric laser scanner having: a laser for the approximately perpendicular illumination of a smooth surface, a scanning mirror, and a telecentric optical system for guiding illumination and detection beams; and a detection unit having: an optical detector system, a central diaphragm positioned concentrically in the vicinity of the optical detector system toward the telecentric laser scanner, a highly sensitive photomultiplier for detecting scattered light, which emanates from defects on smooth surfaces, and a slit diaphragm arranged upstream of the photomultiplier, wherein in the case of an incomplete rotationally-symmetrical configuration of the optical detection system, a second sensor is provided with an aperture range overlapping the first sensor, the scanning line of which forms an angle to the scanning line of the first sensor.