| 摘要 |
PURPOSE:To enable accurate inspection over the entire surface of a printed circuit board, by a method wherein a contact type image sensor is used to automatically discriminate the number of holes of the printed circuit board and an output thereof is compared with a reference value at an arithmetic processing section. CONSTITUTION:A printed circuit board 15 as object to be inspected passes under a contact type image sensor 13 on a conveyor 16. At this point, light from a light source 14 passes through holes of the circuit board 15 to form a bright-dark pattern on a light receiving surface in the sensor 13 corresponding to the size and array of the holes and the pattern is converted into an electrical signal accordingly. The electrical signal is sent to an arithmetic processing section in a controller 12, where a computation is performed according to measuring conditions previously inputted with external input unit 11, for example, the number, size and geometry of the holes within the circuit board 15. When the circuit board 15 just passes under them sensor 13, the arithmetic processing section converts the results of computation into a signal corresponding to the external input/output unit 11 to be sent out. |
