PURPOSE: To detect a seam of a fabric accurately regardless of difference in the thickness, by providing light receiving elements with the width roughly equal to the image width of the seam by two stages in the direction of transferring the fabric to perform a differential detection processing of outputs of the light receiving elements.
CONSTITUTION: A mean 2 having a fabric 1 passes between a projector 3 and a light receiver 4. With the passage of the seam 2, first, a light reception signal is outputted from a first light receiving element 51 of the light receiver 4 and than, the seam light reception signal is outputted from a second light receiving element 52. The two signals undergoes a differential detection processing with a differential amplifier 6 and a rectification integrating processing to be a reference value of a seam discrimination/detection comparator. An output of a filter circuit 7 is compared with an output of an auto-level controller 8 by a comparator 9 with the values within a range of set value, it is determined to be seam detection signal to be inputted into a one-shot multivibrator 10. A signal of the one-shot multivibrator 10 activates a relay 11 to allow the detection of the seam of the fabric 1 that has passed.
NAMIKATA MASAYA
JPS52108848A | 1977-09-12 | |||
JPS5673374A | 1981-06-18 |