Three-component lens zoom-afocal transfocal systems

Abstract

Parametric synthesis of zoom-afocal optical systems for zooms. Development of an algorithm for overall calculation of three-component zoom-afocal systems taking into account their overall limitations, ensuring the required range of change in angular magnification and field of view of the zoom lens, admissible vignetting of extreme beams of rays when changing the field of view in the entire specified range. Synthesis of an afocal system for a fixed lens, the entrance pupil of which is behind the afocal system. Creation of a universal analytical and suitable for computer automation algorithm for calculating the optical and dimensional parameters of the components of zoom-afocal three-component zoom systems. The zoom-afocal system is represented by thin components. A system of equations is created in which the distances between the components are unknown. The values of these distances are determined from the equations, which provide the required values of the angular magnification and zero optical power of the afocal system. At the same time, the values of the optical powers of the components and their ratio should ensure positive values of the distances between them. Using the formulas for the angles and heights of zero rays on the components of the system and taking into account the permissible vignetting of the beam from the edge of the field of view, the required light diameters of the components are determined. The obtained analytical dependencies make it possible to determine the focal distances of its components and their relative location over the entire range of the desired change in angular magnification based on the initial data on the admissible longitudinal and transverse dimensions of the afocal system. It was established that the afocal system has a maximum axial length at an angular magnification of one. The first component needs the largest light diameter. The diameter of this component reaches its largest value when the angular increase approaches unity. The obtained results make it possible to analytically carry out a parametric synthesis of three-component zoom-afocal systems, taking into account the requirements for their dimensions, the range of changes in the angular magnification and the permissible vignetting of the beam beams from the edge of the field of view.