METHOD AND APPARATUS FOR MEASURING SURFACE CONFIGURATION

摘要

An method and corresponding apparatus for measuring the configuration of a surface of a medium are disclosed. The apparatus comprises: a pattern; a detector arranged to sense the pattern via the surface of the medium and to produce an output signal; a driver arranged to move the medium and pattern relative to each other; and a processor arranged to measure the variation in the output signal of the detector while the medium and the pattern are in motion relative to each other to measure the distortion of the pattern when sensed via the surface of the medium.