| 摘要 |
Apparatus for detecting the presence of extraneous matter and/or cracks in translucent containers and in particular translucent containers when the colour density and/or wall thickness of the translucent containers vary significantly from container to container which includes a vertical spot beam of light which is projected through the container to generate an electrical inspection signal corresponding to the amount of light passing through the container. This electrical inspection signal is compared with a predetermined electrical acceptance signal, which is a function of the vertical position of the spot beam of light relative to the container. There is an ambient light correction and for colored containers either the inspection signal or the acceptance signal is altered during the inspection process to take account of the colored density and/or wall thickness. |
