| 摘要 |
PURPOSE:To make it possible to measure quantity of eccentricity with high accuracy within a short time, by measuring the quantity of eccentricity of a lens by converting the same to a numerical value by using a computer. CONSTITUTION:The light from a light source is projected to the lens 43 to be inspected held to a lens frame 44 through a lens system 42 and the transmitted light is condensed to a focus position to form a spot image. This spot image is magnified by a lens system to be formed onto a light position detection element 46 and converted to X.Y voltage wherein the position of the centroid is linear in two directions X, Y. The output of the X.Y voltage is amplified by an amplifier 10 and converted to digital output by an A/D converter 13 to be inputted to a computer 14. Next, when a lens 5 to be inspected is rotated on the basis of a frame 6, the X.Y output of a light position detection element 9 changes when the lens 5 to be inspected is eccentric because the spot image draws a circle and the area of said circle is calculated by the computer 14 and the radius of said circle is subsequently calculated to calculate the quantity of eccentricity of the lens to be inspected. |
