Method and device for measuring transverse magnification of optical system by means of uniform-speed moving point targets

Abstract

A method and a device for measuring transverse magnification of an optical system by means of uniform-speed moving point targets belong to the field of metering equipment characterized by an optical method. The method includes: imaging point targets moving at a uniform speed to obtain a linear image; finding the value range of pixel spacing in a frequency domain; and calculating the transverse magnification of the optical system by means of genetic algorithm according to the fact that a practical modulation transfer function curve and a theoretic modulation transfer function curve related to the pixel spacing have the highest overlap ratio under the least square condition. In the device, sliders for bearing the point targets are mounted on a first guide rail and a second guide rail, a controller controls the sliders to move on the first guide rail at a uniform speed while controlling the sliders to move on the second guide rail, and movements in two directions are matched with each other, so that the point targets are constantly focused and imaged on the surface of an image sensor during movement. By the aid of the method and the device for measuring the transverse magnification of the optical system, errors of single measuring results can be decreased, and further repeatability of measuring results is improved.

Description

technical field [0001] The method and device for measuring the lateral magnification of an optical system using a uniform moving point target belongs to the field of metrology equipment characterized by the use of optical methods, and in particular relates to a point light source that moves in a straight line at a uniform speed as a target, and uses a constant moving image MTF in the frequency domain to measure A method and device for measuring the lateral magnification of an optical system. Background technique [0002] The lateral magnification of the optical system is a very important parameter in the field of medicine and precision measurement. It not only indicates the technical index of the optical system, but also can use this technical index to carry out precise measurement of other parameters. However, how to obtain the lateral magnification of an optical system is the primary problem in carrying out this work. [0003] 1. The measurement method of the lateral magn...

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Problems solved by technology

[0028] The present invention aims at the large distortion optical system of the above-mentioned existing measurement method, which is not suitable for measurement in a large field of view, but in a small field of view, there is the problem of low repeatability of lateral magnification measurement, and the existing measurement device has the problem of separation In view of the problem of focusing, a method and device for measuring the lateral magnification of an optical system is proposed. This method can improve the repeatability of measurement results in a small field of view and is more suitable for measuring the lateral magnification of a large distortion optical system; the device can eliminate defocus Influence on the measurement results, further improving the repeatability of the measurement results

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