Topography measuring apparatus

Abstract

A contour measuring apparatus and method of using the same is disclosed to measure the three-dimensional contour of a surface. Structure is provided to direct first light beams onto the surface being measured. Reflections of the first light beams from the surface are received for generating electrical output signals corresponding to electro-optically measurable optical images. Each of the images corresponds to the location of the first light beams. Structure determines the approximate location of the center of the surface being measured with respect to an optical axis extending through the contour measuring apparatus. The location determining structure comprises a component for directing a single light beam along the optical axis of the contour measuring apparatus onto the surface being measured so as to reflect to the means for generating electrical output signals. Also, structure generates a pattern in the component for generating electrical output signals corresponding to the location of the optical axis to the contour measuring apparatus. Moreover, the apparatus includes an element to compare the location of the center of the surface being measured with the location of the optical axis.