| 摘要 |
PROBLEM TO BE SOLVED: To provide a roundness measurement method and a device thereof which have high accuracy and are highly versatile.SOLUTION: In the roundness measurement method, the operation of moving a confocal probe 2 which has the projected light focal length set to a radius of an inspection target hole and is arranged based on a substantial center of the inspection target hole, by a very small amount in the radial direction in an area from a position shorter than the projected light focal length and a position longer than the projected light focal length and of defining a position where brightness of reflected light from the inner surface of the inspection target hole is maximum, as a measured radius, is repeated in directions in which the entire circumference of the inspection target hole is equiangularly divided, and the roundness of the inspection target hole is measured on the basis of a reference radius based on the least square method. The device includes: a distance measurement mechanism 4 which detects an amount of movement of the confocal probe 2 moving by the very small amount in the radial direction in the area based on the projected light focal length; a photodetector 12 which detects brightness of reflected light from the inner surface of the inspection target hole; and an arithmetic processing unit which repeats the operation of defining the position where the brightness is maximum, as a measured radius, in the directions in which the entire circumference of the inspection target hole is equiangularly divided, and measures the roundness of the inspection target hole on the basis of the reference radius based on the least square method. |
