DEVICE FOR DETECTING IRREGULARITIES IN A MOVING MATERIAL

摘要: A device for detecting irregularities in a moving sheet material by detection of light means photodetectors after reflection from or passage through the sheet. The output signals each photodetector are filtered, amplified, clipped and discriminated discriminating detector to separate smaller greater irregularities. An AND-gate which unclipped series photo-detectors fed, permits retrieval extending over width Or-gates unfiltered permit serious defects material.