CALCULATION OF THE OBJECT BOUNDARY POSITION AFTER ITS PROJECTION IN A SPATIALLY NONINVARIANT COHERENT OPTICAL SYSTEM
Yu. V. Chugui1,2,3
1Technological Design Institute of Scientific Instrument Engineering, Siberian Branch, Russian Academy of Sciences, ul. Russkaya, 41, Novosibirsk 630058
2Novosibirsk State University, ul. Pirogova, 2, Novosibirsk 630090
3Novosibirsk State Technical University, prosp. K. Marksa, 20, Novosibirsk 630073
Keywords: дифракция света, телецентрические проекционные системы, фурье-оптика, размерный контроль, light diffraction, telecentric projection systems, Fourier optics, dimensional inspection
Abstract
Specific features of half-plane image formation in a coherent optical spatially noninvariant (aberration-free) system of the 2F-2F telecentric type with a limited aperture of the projection lens (in the absence of the spatial frequency filter) are studied. The dependence of the light intensity behavior at a point corresponding to the half-plane boundary in the image on the object position is found in an analytical form on the basis of approximating the Fresnel functions by analytical functions. As the half-plane approaches the boundary of the field of vision of the system determined by the lens aperture diameter, the light intensity is demonstrated to deviate significantly from that in the case of the axial position of the half-plane, which may lead to noticeable measurement errors in inspecting the geometric parameters of objects by the projection method in transmitted light.
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