ソフトウェアデータムによる段差形状の測定

Abstract

It is important for precision profile measurements on on-machine conditions to construct some accurate datum for scanning. Any preceding method using software datum is not possible to measure step-wise profiles accurately. In the inclination method, it is necessary to hold some distance between two displacement sensors and in most cases the distance is too wide to represent a sharp edged stepwise profile. The generalized 3-probe method and other methods using software datum can represent more higher frequency components than the inclination method. However the shape of step can not yet be expressed because of Gibbs's phenomenon in the Fourier transform which is used for deconvolution. In the present paper it is proposed to combine the inclination method and 2- or 3-probe method. The new method determines the relative height between the discrete data groups of the inclination method by using generalized 2- or 3-probe method. And the new combining method can maintain the advantage of the inclination method that the discrete data present rigorously the original relative height of sampled points without any errors of data processing.