| 摘要 |
PURPOSE:To remove the instability in the manufacturing process and to make it possible to perform the stabilized pattern inspection by performing the first characteristic extraction, performing the comparison with previous reference data, and detecting only the defect. CONSTITUTION:At first, the image of a printed board 101 to be inspected is picked up with an image inputting means 103, and the vairable-density image is obtained. Then, the variable- density image is converted into the binary image with a binarizing means 105 at a threshold level, which is obtained based on a density hystogram and the like beforehand. The binary image is reduced by the specified pixels (n) from the background side with a thinning means 106 with linking property being maintained. Thus, the linked skeleton image is obtained. A first characteristic extracting means 107 extracts the characteristics such as the terminating ends and T branches out of the skeleton image. A second characteristic extracting means 109 extracts the terminating ends of and the T branches out of the skeleton images at the nth stage and the (n) stage + or -(m)th stage out of the thinning means 106 with regard to a standard good board beforehand. A characteristic information memory means 110 stores the result as the reference data. In a judging means 108, the extracted information from the extracting means 107 for the board under inspection is compared with the reference data from the memory means 110, and only the defect is detected. |
