| 摘要 |
PURPOSE:To detect accurately the defect of wiring pattern by providing a pattern detector, which detects a reflected light and a transmitted light to detect the defect of a wiring pattern, and a filter through which both light beams have wavelength regions different from each other. CONSTITUTION:Light 31 emitted from a light source 11 has the optical path changed at 90 deg. by a half imrror 23 and is irradiated to a wiring surface 2 of a printed board 1 and is returned upward as a reflected light from a wiring pattern 3. Light 32 emitted from a light source 11' is irradiated to a wiring surface 2' of the printed board 1 from an oblique direction through a plane mirror 27 and reaches positions above the print board 1 as a transmitted light. Light 45 resulting from joint between the reflected light and the transmitted light is divided into two by a half mirror 23', and one reaches a detector 13 to obtain a positive pattern of the wiring pattern of the printed board 1. The other reaches a detector 13' to obtain a negative pattern of the wiring of the printed board 1. Outputs from detectors 13 and 13' pass comparators 51 and 51' and an OR circuit 52 to become digital signals 65 and 65', and a break 5, where only the upper part is broken, of the wiring pattern on a line A-A and a remaining copper 6 between wiring patterns on a line B-B are detected. |
