| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a measuring method in which the distortion of a transparent resin sheet or the like can be discriminated visually and easily by means of a flow mark by a method wherein a geometrical pattern is imaged, through the transparent resin sheet or the like, by a camera which is arranged in such a way that an angle formed by the optical axis of a lens and by the face of the transparent resin sheet or the like becomes a specific angle. SOLUTION: A transparent resin sheet or the like 1 is piled up on a geometrical pattern 2 which is drawn on a plane. In addition, a camera 3 is arranged in such a way that an angleαformed by the optical axis of the camera 3 and by the sheet or the like 1 is at 10 to 80 deg.. When the angleαis less than 10 deg., the disorder of the outline of the pattern is extreme, but the contrast of the pattern is lowered as a whole. When the angle exceeds 80 deg., the contrast is sufficient, but the disorder of the outline cannot be amplified. The pattern 2 is photographed by the camera 3 through the sheet or the like 1. Thereby, the distortion of the sheet or the like 1 due to a flow mark on the sheet or the like 1 is reflected on the distortion of the outline of the pattern 2, and the dislocation can be discriminated visually and easily.</p> |
