JPS57110908A - Measuring method for shape of object - Google Patents

Abstract

PURPOSE:To measure a shape of an object, by utilizing the fact that, when incident light to a certain point on a surface of an object having a curved shape and to another point and the reflection lights of said incident lights satisfy a geometrical condition, said two points are judged as being located in a contour position. CONSTITUTION:A point P1 and a point P2 in a projection light device on an axis line L in common to a projection light device 10 and a collector 12 are produced, a projection light, which is caused to pass a point P positioned at a distance l1 from the axis line L, is reflected by a point A1 and a point A2, and a reflection light, passing through a point Q located at a distance l1 from the axis line L, is collected at a point Q1 and a point Q2 on a photoelectric conversion surface on the axis line L. In the case of P1P2=Q1Q2, the points A1 and A2 on the object pass PQ, and are positioned at an equal distance from a plane perpendicular to a paper surface. Through the rotation of a projector, P1 and P2 are projected in order at a pitch DELTAx to analyze an image-formation on a photoelectric conversion surface 13, and this obtains a contour line.