| 摘要 |
PROBLEM TO BE SOLVED: To measure the radius of curvature of the curve of a contact lens at a plurality of angles. SOLUTION: A reticle 13 has a plurality of line segments crossing each other at preset angles, and a light emitted from a light source 11 is reflected from a contact lens 18 placed on a stage 17 through the reticle 13, a reticle focusing lens 14, a half mirror 15 and an object lens 16, trapped as an image signal through a focusing lens 20 by a CCD 21, A/D converted by an A/D converter 22, and stored in an image memory 23. The image signal includes the image of the reticle 13. A filter part 24 uses two-stage filters for filtering the image signal read out of the image memory 23. Thus, components corresponding to the line segments in specified directions are only extracted from the image of the reticle 13. The radius of curvature is found in accordance with the extracted components. COPYRIGHT: (C)2005,JPO&NCIPI
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