| 摘要 |
PROBLEM TO BE SOLVED: To inspect a distortion of a plate material to be inspected and the surface thereof with a miniaturized apparatus by a method wherein a specified inspection pattern formed by an inspection pattern forming means is made to pass through a plate material to be inspected, and the pattern is photographed by a camera arranged therebehind and the results are analyzed by an image analysis means. SOLUTION: When projected by a projector 4 onto a screen 1, an inspection pattern is made to pass through a sample plate 2 to be taken by a CCD camera 3. When an internal distortion exists at any point as the pattern pass, the pattern is photographed being deformed oval or into other shapes according to the degree of the distortion. The resulting image is sent to an image analysis part 5 to be turned black and white by a binary coding so that a measuring range is limited to obtain image data of round shapes by inversion and the diameter of each round shape is measured. A standard deviation of the diameter of all the round shapes is calculated separately in the vertical and horizontal directions of each oval form corresponding to the distortion. A ratio between a standard deviation actually calculated for the sample plate 2 as object to be inspected and the standard deviation of the plate material as reference sample stored in the image analysis part 5 is converted to obtain a standard deviation ratio thereby objectively learning the internal distortion. |
