| 摘要 |
PURPOSE: To measure the inclination of a geometric pattern having one or more angular pattern sections in two axial directions over a wide range with high accuracy by irradiating the pattern with light and making an image forming side to intersect a linear array at two points. CONSTITUTION: An illuminating luminous flux 10 from a light source 2 forms an image on a linear array 8 through a carrier 3, optical systems 4 and 5, and a liquid prism 1. In this case, a geometric pattern composed of individual angular pattern sections 13 is arranged on the carrier 3. The horizontal liquid section 9 of the prism 1 becomes horizontal 20 due to the action of the gravity and forms an optical wedge which refracts the parallel luminous flux 10 together with sealing glass 11 and the image of the geometric pattern is formed on the array 8 through the optical system 5. In this image, the two sides 15 and 16 of a pattern section 13 respectively intersect the array 8 at points A1 and A2 . As a result, the X-Y inclination of the section 13 is found from equations, Ys =(A1 +A2 )/2 and Xs =(A2 -A1 )/2.ctgα, by using the positional deviation (Ys , Xs ) of the tip of the section 13.
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