Method and apparatus for measuring the height of an object

摘要

A method and an apparatus for measuring the height of an apex of an object with high accuracy without influence of the surface state of the object are disclosed. Correlation coefficients of respective positions of a waveform formed from digital data indicative of the height of the object detected by a head portion of a detector and a previously prepared standard waveform are calculated while moving the waveforms in the vertical and horizontal directions and the height of an apex position of the standard waveform at a position having a largest correlation coefficient from the calculated result is decided as the height of the apex of the object. Accordingly, the height of the apex can be decided from the whole detected waveforms without influence of local abnormality of the reflected light quantity waveform due to minute ruggedness or discoloration of the surface of the object.