Procedure and device to acquire an image, in three dimensions, of a small object with a light pencil and a calibration method for such an acquirement.

摘要

The invention relates to a method of acquisition of a three-dimensional image of a small object by light-beam tracing, in which: - the object is scanned with a coherent pencil along a first axis (X); - the object is moved along a second axis (Y), perpendicularly to the first; - the pencil reflected by the object is analysed using a camera of the linear CCD type, by comparing the video signal output from the camera with a predetermined threshold, by storing the address of the first pixel in question, when the threshold is exceeded, as well as the value of the p following pixels corresponding to an image spot (33); - the coordinates of the object along the third axis (Z) are obtained by laser triangulation with point-by-point sweeping, by considering any point in the field of view of the camera with its three-dimensional coordinates to be a linear combination of n reference points. The invention also relates to a device for acquisition of a three-dimensional image, as well as a sampling means. Application in particular to automatic machining of ceramic dental prostheses (false teeth).