| 摘要 |
<p>A method and apparatus for inspecting a transparent container (8) for refractive defects includes positioning a light source (1), a detector (22) and a processor (38) operatively associated with the detector (22). A grid filter (44), placed in front of the light source (1), has a plurality of alternating dark and light bamds so as to provide a multiple intensity gradient in the form of a generally triangular wave to the container (8) when it is positioned between the grid (4) and the detector (22). Refractive defects will cause a distortion of the intensity gradient which will be recieved by the detector (22). The processor (38) receives the electrical signals emitted by the detector (22) and determines whether refractive defects exist in the container (8) while ignoring desired irregularities.</p> |
