| 摘要 |
PROBLEM TO BE SOLVED: To perform automatic scanning measurement even for a subject, whose profile shape is bent at an acute angle, by setting the new detecting region by moving the subject to the specified position when the edge is not detected in the inspecting region. SOLUTION: A control unit moves an edge detecting region (index) 15 along the profile shape of a subject and detects the edge position. When the edge is not detected in the moved index 15, a new index 15, which is moved so as to overlap partially on the index 15, whose edge is not detected, on the approximate arc with the edge position detected immediately before as the center, is set. That is to say, the position of a pitch L on a measuring target 30 estimated by an interpolation from a measuring point 18b immediately before and a measuring point 18c before 18b is made to be a measuring target point 18a, and the index 15 is moved. When the edge is not detected in the index 15, the target point is changed to measuring target points 18a1, 18a2, 18a3..., and the index is moved to the positions of target points. Then, the operation is repeated until the edge is detected in the index 15 at the position after the movement. |
