Machine vision equipment can provide surface inspections over a wide area. The Stain tool and Fine Colour can be used to detect bead positions from the degree of colour change. This feature enables the sensor to handle variations without having to adjust the sensitivity for each lot.
Fibre sensors or colour sensors were previously used to detect bead positions. This method caused detection errors when spots or variations in surface conditions between lots were incorrectly identified as beads. Using machine vision equipment prevents the operation errors responsible for defects being missed and line shutdowns.