| 摘要 |
PROBLEM TO BE SOLVED: To increase accuracy of shape measurements by implementing highly accurate position detection even for a front surface reflection spot in which a rear surface reflection spot is shorter than a prescribed distance.SOLUTION: Of front surface reflection spots present in a spot image to be obtained by an image pick-up element, the front surface reflection spot is selected that has a rear surface reflection spot overlapped, and an inspected lens is moved to separate the selected front surface reflection spot from the rear surface reflection spot, and an amount of movement is stored (S4 and S5). From a spot image to be obtained by the image pick-up element after moved, a position of the front surface reflection spot away from the rear surface reflection spot is acquired (S6). The acquired position of the front surface reflection spot is corrected in accordance with the amount of movement, and the corrected position thereof is calculated as a pre-moved position (S7). Then, the corrected and calculated position of the front surface reflection spot is used to calculate a front surface shape of the inspected lens (S9).SELECTED DRAWING: Figure 3 |
