摘要 |
Transparent objects having at least a localized region with symmetry of revolution are optically inspected by moving them to an examining station, locally illuminating each of them at the examining station with a plurality of circularly scanned fixed light beams, and detecting light from each by a plurality of successively interrogated fixed detection areas. In a preferred embodiment, the illumination is carried out by circular scanning in successive steps about the object with a plurality of differently-oriented, fixed light beams. At least one detection area is interrogated for each illumination step. |