| 摘要 |
PURPOSE:To continuously vary the space frequency for measuring MTF by varying the linear direction of a grid chart with respect to the arranged direction of light receiving elements, in a device which projects the grid chart image on solid scanning elements through an optical element to be inspected, and the transmission function (MTF) of the optical element is measured by the outputs of the above scanning elements. CONSTITUTION:A light ray emitted from a light source 22 is focused on a focusing lens 23, and forms an image of a chart 24 on solid scanning elements 281 through 289 arranged on a plate 29 through a lens 26 to be inspected. The solid scanning element 28 has a self scanning function as CCD or the like, and converts the waveform signal of the spatial chart 24 into a time waveform signal. The image of the chart projected on the plate 29 is rotated by a rotary device 25, and can assume various angles with respect to the arrangement of unit light receiving elements. Accordingly, MTF values corresponding to spatial frequencies continuously varying with respect to nine image heights including the optical axis corresponding point can be simultaneously obtained. |
