| 摘要 |
PURPOSE:To inspect with a high accuracy and quickly an appearance by detecting as a defective point a point where a level variation quantity of a picture signal of an object to be inspected exceeds a threshold level set in advance, and counting the number of defective points. CONSTITUTION:An output of a two-dimensional image sensor 15 placed opposingly to a surface to be inspected of an object 11 to be inspected is supplied to the first and the second defect detecting circuits 17, 18. These defect detecting circuits 17, 18 detect a defective point by detecting continuously a level variation quantity per a prescribed time of continuous picture signals in the scanning direction, and a level variation quantity in a synchronizing position of a two picture signals in the scanning direction outputted from the image sensor 15, and comparing an absolute value of each level variation quantity detected in this way, with a threshold level set in advance, respectively. The number of this defective point is counted by quantity deciding circuits 28, 38, and when its count value exceeds a standard value, a fault of the object 11 to be inspected is detected. |
