Abstract: 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.

Abstract: A system for detecting the breaking of the woof in a shuttleless weaving machine wherein the woof is drawn into the machine from a supply.

Abstract: An automatic control apparatus for a weaving machine is disclosed, which includes a photoelectric detecting scheme provided at a reed of the machine such that a light beam thereof penetrates the shed of the warp sheet and detects improperly shedded warp. A timing switch is coupled to a crank shaft for generating a timing signal at a predetermined angle of the crank shaft, and delay circuits are provided for delaying the timing signal so as to generate a gate control signal. The leading and/or trailing edges of the gate control signal are defined by the delay circuits and a gate circuit is included which is responsive to the gate control signal for allowing the warp detected signal to be gated. A wave shaping circuit receives the warp detected signal as gated and provides wave shaped signals thereof. A charge storing capacitor is connected to receive wave shaped signal, said the charge voltage thereof is threshold detected to provide a control signal.