METHOD FOR SEARCHING FOR MEASUREMENT ORIGIN OF SHAPE- MEASURING APPARATUS

PROBLEM TO BE SOLVED: To automatically estimate coordinates of an end face of an object to be measured from coordinates of a contact point by scanning a probe in contact with a face to be measured, measuring coordinate data of a scanning locus, and estimating the coordinates of the end face of the object from measured data. SOLUTION: Each coordinate point of coordinate point sequence data measured when an end face part is scanned with the use of a contact type probe having a tip end radius on the order of mm indicates a center position of a leading end sphere of the probe. Symbols of P1-P14 are applied to coordinate points, and a contact point of the probe tip end is estimated from two adjacent coordinate points. Coordinates of the P1 and P2 are set respectively to (X1, Z1) and (X2, Z2), and coordinates of a contact point Q1 estimated from the coordinate points P1 and P2 are set to (XQ1, ZQ1), whereby coordinates of Q2-Q13 are derived. The Q8-Q13 are overlapped nearly at one point and, this point, i.e., a position of a highest density of the estimated contact points is the end part to be obtained. Coordinates of the end part can be easily read by displaying a graph to a display device or displaying a cursor position.