Patent ID: 6269142
Filing Date: 2001-07-31
Classification: G01N,G01V

Abstract:
An imaging system for inspecting a target object, comprising:an x-ray source for producing a fan beam of x-rays directed toward the target object along a scan line of a plurality of scan lines;a fan beam stop comprising at least one radial arm having an arm width extending from a rotating axis to intersect the fan beam, the radial arm interrupting a portion of the fan beam as the at least one radial arm rotates through the fan beam;a transmission x-ray detector positioned in the scan line of the fan beam for producing a transmission signal representative of a portion of the target object intersecting the scan line;an inspection surface positioned between the x-ray source and the transmission x-ray detector for moving the target object through the fan beam;at least one back-scatter detector positioned within a detection range of the inspection surface for receiving x-rays scattered from the objects and for producing a back-scatter signal representative of the intensity of the x-rays scattered from the objects, wherein the spatial resolution along the scan line is obtained by the radial arm interruption of the fan beam, and wherein each interrupted portion of the fan beam defines a pixel of the back-scatter signal; anda processing means for producing a back-scatter image from the back-scatter signal and a transmission image from the transmission signal to produce an image of the objects.