| 摘要 |
PURPOSE:To improve detection accuracy for 'fogging' by calculating the gradient of the brightness distribution curve of a pattern to be inspected and deciding whether or not the object pattern is normal by using the number of peaks of a differential curve obtained from the calculated gradient and respective peak values. CONSTITUTION:A differentiating circuit 5 calculates the gradient of the brightness distribution curve of the pattern to be inspected along a specific inspection line obtained through an image pickup means 1, an A/D converting means 2, a storage means 3, and a smoothing means 4. Then a deciding means 6 compares the number of peaks of the differential curve obtained from the gradient of the brightness distribution curve calculated by the differentiating means 5 and the respective peak values with the specific value of the number of peaks which is set according to a master pattern and the threshold value of the peak values to decide whether or not the inspected pattern is normal, namely, whether or not 'fogging' is caused (whether or not the resin of a display pattern part is covered with the resin of a background pattern part). |
