Abstract: A printed circuit board inspection system acquires images for purposes of inspection from viewing fields defined along the surface of the printed circuit board to be inspected which can be varied in size to accommodate the density and tolerance of components associated with the printed circuit board under inspection. To this end, the cameras of the inspection head associated with the printed circuit board inspection system are provided with zoom lenses, which are capable of controlled operation responsive to the existing microprocessor systems of the printed circuit board inspection system. This allows the magnification of images acquired by the cameras to be varied, as desired, in turn varying the size of the viewing fields defined for inspection purposes. The inspection head is then operated at a rate commensurate with the size of the viewing fields which have been selected.

Abstract: A method and apparatus for inspecting articles such as printed circuit boards doubles the transport rate for the article under inspection, and modifies the manner in which acquired video images are processed to account for this change in rate. Primarily, this involves two modifications to existing video processing systems including a change in synchronization for obtaining the frames which are to be processed, and a selective exposure (i.e., shuttering) of the video cameras to the images which are to be acquired in order to avoid the acquisition of plural images in a single frame. Once acquired, the video images are stored and processed making use of techniques which substantially correspond to those previously employed by existing inspection devices of this general type.