| 摘要 |
PROBLEM TO BE SOLVED: To provide a length measurement device and a length measurement method capable of estimating distance from an imaging surface of an image device to a surface of a sample without moving the imaging device and an optical element for performing focusing.SOLUTION: A range of a part of a rugged surface focused by adjusting a drive part 104 is detected, a position of a scale 105 at the time is read, the read position of the scale 105 is output to a storage part by using actually measured distance zn from an imaging surface of an imaging device 102 to the focused rugged surface of a sample 110 and an image in corresponding to the actually measured distance zn as reference data. An image Im photographed by changing distance to the one so that at least a part is focused in the same area by adjusting the drive part 104 is output to the storage part as object data. Coincidence Cnm with all the images in (N=1-N) of a reference data set is calculated to the image Im by an image processing part. The minimum coincidence Cnm_min is calculated, and estimated distance Z'n is estimated at an estimation part.SELECTED DRAWING: Figure 1 |
