| 摘要 |
PURPOSE:To detect a parts with good contrast even when the reflectivity of a surface to be detected is not uniform by allowing two line sensors to detect reflected light beams obtained from a printed circuit board part and the top surface of the parts by irradiating a light beam. CONSTITUTION:A printed circuit board P is irradiated with the slit beam l2 slantingly above by a semiconductor laser 12, a collimator lens 13, and a cylindrical lens 14. Then, the reflected light l3 from the circuit board part R of the printed plate P and the reflected light l2 from the top surface of the parts having specific height are detected by 1st and the 2nd line sensors 17 and 18 in a direction different from the irradiation direction of the beam l1. Then, comparators 21-23 and an OR circuit 24 compare the intensity levels of the output signals of the 1st and the 2nd line sensors 17 and 18 with each other and judges the package state of the parts having the specific height based on the comparison result. Consequently, the parts can be detected with good contrast even if the reflectivity of the surface to be detected is not uniform.
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