Patent attributes
The present invention relates to a mark partitioning inspection method. A reference image and an inspection image are respectively acquired, and a correlation in a character unit for the reference image and the inspection image is obtained, and then the correlation value is compared with a first threshold value that has been previously set. Then, when the correlation value is greater than the first threshold value, the relevant character is partitioned into a predetermined number of regions, and a correlation between the reference image and the inspection image is obtained for each of the partitioned regions, and then a difference between the maximum and minimum values of the correlation is compared with a second threshold value that has been previously set. Here, even if a low defectiveness is revealed, the mark partitioning inspection method is capable of precisely determining whether or not it is defective, by determining the inspection image to be defective if the difference between the maximum and minimum values of the correlation is greater than the second threshold value, and by determining the inspection image to be normal when the difference between the maximum and minimum values of the correlation is smaller than the second threshold value.
