| 摘要 |
<p>Observation means, for example a TV camera 13, for inspecting an object, e.g. a printed wiring board 11, is focused on an inspection point on the board 11 by using a calculated distance from the camera 13 to the inspection point, without actual distance measurement. The distance is calculated using a plane equation representing one of a group of plane surfaces, e.g. triangles T1 to T8. The plane equation is derived from distances, measured in advance, from the camera 13 to reference points (P1 to P9) on the board. Distance calculation and focussing of the camera 13 at the calculated distance take place at the same time as the camera and board are more relative to one another to bring the inspection point into the line of sight of the camera.</p> |
