| 摘要 |
Method and apparatus for optical inspection of transparent layers such as the wall of glass and plastic containers, using bifurcated fiber optic probes. One or more of such fiber optic probes are directed at the wall of a transparent container, and light emitted thereby is selectively reflected from both the inner and outer surfaces of the container wall. Each probe includes a pair of bifurcated fiber optic bundles which are disposed at different distances behind a 1:1 lens system, resulting in two focal points at different distances from the fiber optic probe. Relative motion of the inner and outer wall surfaces between these focal points results in measurable variations of the probe output signals, which variations may be interpreted to track wall thickness and concentricity. An alternative detection scheme uses a probe with a single bifurcated bundle, and reciprocates such probe relative to the container wall while measuring the separation of null points of the output signal.
|
