Method and device for measuring lateral magnification of optical system by combining point target images

Abstract

The invention provides a lateral magnification measuring method for a point target image-spliced optical system and a lateral magnification measuring device, belonging to the field of metering equipment which takes an optical method as the characteristic. According to the method, a point target is under different view fields and is imaged twice, a linear image is formed according to two point target images, the dereferencing range of a pixel distance is searched in a frequency domain, and according to the condition that a practical modulation transfer function curve and a theoretical modulation transfer function curve, which are related with the pixel distance, the contact ratio is best in the case of least squares, the lateral magnification of the optical system is computed by a search algorithm; a slide block carried with a point target in the device is arranged on a first guide rail and a second guide rail, and the motion of the slide block on the first guide rail and the motion of the slide block on the second guide rail are matched with each other, so that the point target is exactly focused and imaged to the surface of an image sensor at any view filed position; and the lateral magnification of the optical system is measured by the invention, so that the error among single-measurement results can be preferably reduced, and the repeatability of the measurement results can be further improved.

Description

technical field [0001] The method and device for measuring the lateral magnification of an optical system by combining point target images belongs to the field of metrology equipment characterized by the use of optical methods, and in particular relates to a static point light source as a target, which is measured by using two frames of static point target images in the frequency domain A method and device for 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 magnification of the optical system [000...

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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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