Cloth Weft Counter System by Laser Light for Industrial Use
Light scattering has been applied to a cloth weft counting system, which has been verified for an industrial use, A sheet-like laser light with the length, l, and width, w, is irradiated on the Moire pattern of cloth with the pitch, p. The best results have been obtained with d=(1/3)p~(1/2)p and l=5w~20w depending on the Moire pattern. The present system consists of semiconductor laser as a light source, PIN photodiode as a light detector, an amplifier, a digitizer (ΔV detector) to transform a pseudosine wave to a square wave, an electronic counter and a display. The accuracy of the system has been found to be above 99% under the best condition. The counting frequency of the cloth weft is above 10kHz to be enough for a practical use.
レーザー研究 25(6), 434-437, 1997-06-15