PURPOSE: To accurately and quantitatively sense defects by illuminating a running structure of continuous length, carrying out shading correction of the resultant sensed signal, then changing a signal expansion parameter based on reference color coordinate values of the aforementioned structure and subsequently binarizing the signal.
CONSTITUTION: A fiber structure 1 of continuous length such as a woven or knit fabric or nonwoven fabric or filmy material is run with a roller system and simultaneously illuminated with a standard light source 3 from the upper part in the central part between two feed rollers 2 to illuminate the structure and the reflected light thereof is sensed with a CCD image pickup sensor 4. The resultant output signal is subsequently inputted to a shading correction circuit 5 and corrected. Color coordinate values of the reference part of the aforementioned structure 1 of continuous length are then read through a colorimeter 9 and a signal expansion parameter is changed based on the above- mentioned values. A threshold level is then set and binarized to perform sensing of defects close to human sense.
KOMAI SHIGERU
ISOMI HIDEAKI
SETO MICHIZO
MAEDA SATOSHI
YAMADA YOZO
