3 D IMAGING OF A SUBSTRATE USING PERPENDICULAR SCANNING DIRECTIONS

A system (10) for obtaining a three-dimensional image of a substrate (12) comprises a linescan camera (20) trained on the substrate normal to the plane of its surface to capture the image of a strip of area (S.sub.y) running along a first axis. A reflective member (38), driven by a motor (39), spans a line of light (36) generated by a laser (30) at an angle across the surface of the substrate so each of a plurality of strips of area (S.sub.a,S.sub.b,S.sub.c. . . ), including the strip (S.sub.y) imaged by the camera, is successively illuminated. A processing device (26) is coupled both to the camera (20) and to the motor (39) to synchronize them so that the camera captures the image of the strip within its field of view each time a successive one of the strips (S.sub.a,S.sub.b,S.sub.c. . . S.sub.y) is illuminated. The processing device (26) further serves to process the successively captured images of the strip (S.sub.y) within the field of view of the camera to obtain a three-dimensional image of the strip. A relative motion is imparted between the linescan camera (20) and the substrate (12) by a slide to enable a three-dimensional image of the substrate to be obtained.