| 摘要 |
PURPOSE:To detect various kinds of defects by detecting a reflecting light image and a passing light image of a printed circuit board by one pickup device, and detecting an edge after converting each image to two digits. CONSTITUTION:A wiring pattern on a printed circuit board 101 is illuminated from above by a diffusive illuminating device 104, and input as a dark-bright image through an image input means 102. Likewise, the light modulated by a modulating light generating means 105 is illuminated from below the circuit board 101 and, the image is input to the means 102. A binarization means 106 compares the dark-bright image from the pickup device 103 with a predetermined threshold valve and turned the image into a binarized image. An edge detecting means 107 converts the binarized image into an edge image. Moreover, a deflection means 109 compresses the binarized image from a first expansion means 108 to a predetermined size, and deletes the edge image outside the area of a through hole. A second expansion means 110 expands the binarized image from the means 109 to restore the image into the size of the through hole. A defect detecting means 111 detects a defect with use of the binarized image from the 106 and the through hole image from the mans 110. |
