Patent US 4,664,512

A range finder which measures positions in three-dimensional space of object points within a field of view. Pixel data outputted from pixels in different depths of focus are detected, while said depth of focus is moved. Pairs of pixel data, one outputted from each of two cameras, and which have the same value and each of which is different from pixel data outputted from pixels adjacent the pairs of pixel data are detected. Since the same object point forms its image in pairs of pixels, outputting the pairs of pixel data, permits the object range to be calculated from three factors as the interval between the two cameras, angle of two axes, and the positions of pixels in the two cameras.