| 摘要 |
PURPOSE:To eliminate the harmful signal at the fringe part of an image and thus prevent the misinspection, by setting the region of inspection at the inner side of the substance to be tested based on the fringe of the image of the substance. CONSTITUTION:The video signal Sa obtained through the TV camera is processed by the picture process circuit 11, and thus the feature extracting signal Sx is obtained. This signal Sx is compared with the reference signal er, and the detection signal Sy showing the existence of the defective area is obtained from the comparator 13. On the other hand, the signal Sa is applied to the test region deciding comparator 16, and the horizontal synchronous signal Sc is applied to the time limit signal generating circuits 17 and 18 each. Here the image fringe detecting circuit is formed with the comparator 16, the circuits 17 and 18, the inverter 19 plus the AND circuits 20 and 21 each. Thus the image fringe signal Sg is obtained. The signal Sg is then applied to the time limit signal generating circuits 22 and 23 each, and the test region designation signal Sj is obtained. The signal Sj is supplied to the AND circuit 14 along with the signal Sy, and the circuit 14 delivers the signal showing the result of insepection only for the period during which the signal Sj is generated. |
