CALIBRATION METHOD FOR CONTACT MARKER IN COORDINATE MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a calibration method for a contact marker, in which the calibration value of the contact marker is found with high accuracy, and in which coordinates can be measured with high accuracy by using the calibration value thus obtained. ;SOLUTION: A contact marker 21-1 which is placed on a probe head 12 is brought into contact with a contact marker 21-2 on a measuring table, it is moved in the X-axis direction (or the Y-axis direction), and the shape of the contact marker 21-2 is measured on the basis of the displacement amount in the Z-axis direction of the contact marker 21-1. In the same manner, by using the contact marker 21-1, the shape of a contact marker 21-3 is measured, and the shape of the contact marker 21-3 is measured by using the contact marker 21-2. Respective measured results R1, R2, R3 are the sum (Ra, Rb, Rc) of radiuses of curvature (calibration values) of the contact markers 21-1, 21-2, 21-3. On the basis of the values R1, R2, R3, radiuses of curvature Ra, Rb, Rc of the respective contact markers 21-1, 21-2, 21-3 are computed. As a result, the respective contact markers are calibrated.;COPYRIGHT: (C)1998,JPO