| 摘要 |
PURPOSE:To unnecessitate a nondefective pattern as a comparison, and to unnecessitate a huge hardware for an accurate positioning with a comparing pattern by executing an arithmetic operation of a pattern picture and a mask picture, extracting feature points and detecting a chipping. CONSTITUTION:A center mask subtraction circuit 1 subtracts the picture of a center mask from the inputted picture and outputs a subtraction picture signal (i). A feature point extracting circuit 2 inputs the subtraction picture signal (i), and after executing a line thinning process to the inputted subtraction picture, detects end points and outputs a feature point signal (j). And a peripheral mask confirming circuit 3 outputs a binary picture signal (h) and the feature point signal (j), and confirms the true and false of end points T1 and T2 detected in the feature point detecting circuit 2 as candidate points indicating the chipping of the pattern of a pad, then outputs a chipping detection signal (k). Thus, the nondefective pattern for the comparison is unnecessitated, and the huge software for the accurate positioning with the comparing pattern is unnecessitated. |
