High resolution areal tomosynthesis

Abstract

The present invention is related to laminographic apparatus and method for imaging individual layers of a multilayer structure, for example the individual layers of a composite, with capabilities for imaging in multiple dimensions or along arbitrary surfaces within the space of the structure. A source of radiation and an areal detector are moved relative to a test specimen positioned therebetween such that a magnified two dimensional image of the test specimen is obtained at the detector. A single translational pass of the test specimen through the source/detector combination provides sensitivity to patterns in the test specimen which have small scale features lying in a direction parallel to the direction of the pass. An image with sensitivity to features in two perpendicular directions is obtained by taking passes in both directions, no mechanical registration between the perpendicular passes being required. To reconstruct a point along the pass, only local mechanical registration (over for example an inch or so) between the source, test specimen and detector is required for each pass; each point being reconstructed from a predetermined number of images taken over the short distance for which local mechanical registration was required. One or more surfaces of the test specimen may be reconstructed using digitized data of the images.