| 摘要 |
PURPOSE:To improve the precision in detection of the end of a work piece to be inspected and to lessen regions of the opposite ends of the workpiece being insensitive for inspection, by comprising a detecting circuit using fixed binary-coding jointly with differential binary-coding in detection of the end of the workpiece. CONSTITUTION:A video output signal (a) of a one-dimensional CCD camera 5 is inputted to a differentiating circuit 10 and a fixed binary-coding circuit 11 and it is converted into a video signal differentiation signal (bb) and a video signal fixed binary- coding signal (cc) in these circuits and outputted therefrom. In regard to the differentiated waveform (bb) of the signal (a), a defect detecting circuit 12 reckons it to be a defect signal (b) as to its point being a set threshold value Ld or below or Ld<+> or above. In a window circuit 13, the first point Pe being a set threshold value Lp or below on the above-mentioned differentiated waveform (bb) in a section '1' of the signal (cc) binary-coded at a fixed threshold value Le of the signal (a) is taken as the end E of a workpiece, and thereafter a detection region signal (c) from a section corresponding to the width W of the workpiece and taken as a detection region is generated and outputted. In a defect determining circuit 14, the result (d) of determination is produced by the logical product of the signal (c) and the signal (b) and outputted therefrom. |
