The measurement of a curvature of a surface

摘要

A method of, and apparatus for, measuring the curvature of a specularly reflecting surface in which a beam of light is directed at the surface parallel to the optic axis of an optical element of which the surface forms part, the angle of reflection of the radiation reflected from the surface is determined by measuring the change in orientation of a rotatable mirror from a reference position required to cause the radiation reflected from the surface to be incident upon a detector and there is derived from the separation between the beam of radiation and the optic axis of an optical element of which the surface forms part and the measured angle of reflection of the beam of radiation a measure of the curvature of the surface.