PERIPHERAL LENGTH CORRECTING DEVICE, PERIPHERAL LENGTH MEASURING DEVICE AND SURFACE DEFECT INSPECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a peripheral length correcting device having stable and well reproducible performance by autonomously correcting a displacement D of a metal ring 2a, and to provide a peripheral length measuring device and a surface defect inspecting device.;SOLUTION: The peripheral length correcting device, the peripheral length measuring device or the surface defect inspecting device comprises two pulleys 12, 13 between which the metal ring 2a is bridged. The pulleys 12, 13 have swollen portions 12a formed all over the outer peripheral faces. The swollen portions 12a are swollen outward along the rotating faces of the pulleys 12, 13. Thus, centrifugal force with the rotation of the pulleys 12, 13 is utilized to generate centering force which permits the movement of the metal ring 2a near the thickness centers of the pulleys 12, 13. As a result, even when there is slight "dislocation" of the metal ring 2a bridged between the pulleys 12, 13, the dislocation is autonomously corrected by the centering force.;COPYRIGHT: (C)2006,JPO&NCIPI