Apparatus for detecting defects in sheet material

摘要

An apparatus for detecting a defect in a sheet like material, comprising: a photodetector provided opposite to a textile sheet in the vicinity of the weaving line of a weaving machine, and a prime mover for slidably driving said photodetector in the lateral direction throughout the width of the weaved textile sheet, characterized in that normally the said prime mover is adapted to convert the moving direction whenever the photodetector reaches either side edge of the weaved textile sheet but is further adapted to reverse the moving direction whenever the photodetector detects a defect in the weaved textile sheet, whereby said photodetector is caused to detect repeatedly the same defect and the weaving machine is controlled to stop the weaving operation whenever the photodetector detects the same defect more times than a predetermined number of times.