Apparatus for detecting anomalies in corduroy preparation

Abstract From the Canadian patent

The apparatus detects corduroy cutter needles coming out from the weft yarn loop channels which the needles should cut open, by a laser beam scanning about 10 to 20 times a second, transversely the region where the parallel needles are working. The scanning laser beam creates a diffused light pattern having the general form of a transversal prism, e.g. a cylinder; a plurality of detector devices determines any variation in the light distribution, as to time and lateral distance, in this scattered of diffused light pattern. A logic carrying out and displaying the seanning and detecting as well as stopping the corduroy cutting machine is described too. (Fig. 2)