| 摘要 |
PURPOSE:To judge a flaw, by detecting the width of a waveform corresponding to a flaw part of a video signal to use the size of the flaw as criterion in addition to the light density of the flaw part. CONSTITUTION:Reflected light from an object to be inspected is converted with a photoelectric converter to obtain a video signal A. The video signal A is compared with a light density reference signal 15 by a comparator 11: only when the video signal A exceeds the level of the light density reference signal B, a flaw signal D is outputted. The flat signal D is integrated with an integration circuit 12 to allow the output of signal E having a peak proportional to the pulse width thereof. The signal E and a reference signal F from a reference signal setting circuit 16 are inputted into a comparator 13: when the flaw signal D corresponds to the size of a flaw exceeding a fixed value, a signal H is outputted. Then, the signal H is counted with a counter 14 to output the number of flaws exceeding a fixed value in the size.
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