| 摘要 |
PURPOSE:To achieve an accurate measurement eliminating the need for considering the material condition of an object to be measured by providing a diffusion plate for diffusing light from a lamp, an optical system for forming an image of the diffusion plate at the position where thick surface to be measured of the object and the like. CONSTITUTION:Light emitted by a lamp 1 is uniformized with a diffusion plate 2 to form a bright surface with an area. A condenser lens 3 is used to form an image of the diffusion plate 2 at P, the end face of an object 4 to be measured, namely, near the mesuring surface. At this point, the image formed on the surface P to be measured is made large sufficiently as compared with the section of the object to be measured so that not only a parallel light but also components of lights in the directions L1 and L2 radiate the object being measured. Thus, an image of the diffusion plate 2 ismade on the measuring surface P both upward and downward centered on the object 4 to be measured. This is formed with a light receiving lens 5 to measure the dimension of the thickness thereby enabling accurate measurement eliminating the need for considering material of the object to be measured. |
