Focusing method based on edge spreading function measurement and device

Abstract

The invention provides a focusing device based on edge spreading function measurement. The device comprises a black-white edge target, an optical system, a planar array detector, an image acquisition circuit, an auxiliary focusing device, and a focal length adjustment circuit, wherein the black-white edge target is entirely rectangular and is provided with an edge for dividing the black-white edge target into a black area and a white area; the black-white edge target is arranged in the view field of the optical system; the planar array detector is arranged on the imaging surface focus of the optical system, and the projection of the edge of the black-white edge target on the planar array detector and the pixel orientation direction of the planar array detector form a certain angle; the image acquisition circuit converts original image signals acquired by the planar array detector into digital signals; the auxiliary focusing device is used for acquiring the digital signals in real time and carrying out real-time imaging on the digital signals and carrying out processing the image; and the focal length adjustment circuit is respectively connected with the auxiliary focusing device and the optical system and is used for adjusting the focal length of the optical system according to the image processing result. Therefore, the focusing precision can be improved, and quick, convenient and intuitive focusing result can be obtained.

Description

technical field [0001] The invention relates to the technical field of optical measurement and testing, in particular, the invention relates to a focusing method and device based on edge spread function measurement. Background technique [0002] The optical system has an optimal image plane position for imaging a target at a certain distance, and this position usually satisfies the object-image conjugate relationship, which is called focusing. Deviation from this position will cause the system to go out of focus, resulting in poor image quality and blurred images. The process of adjusting the optical system from defocus to focus is called focusing. The focal length adjustment of the optical system generally takes the definition of imaging as the evaluation standard. For a long time, the focus of the optical system has been adjusted based on the experience of the operator and the clarity of the image judged by the naked eye. This will inevitably add personal subjective pref...

AI Technical Summary

Problems solved by technology

[0004] The focusing accuracy of the existing auxiliary focusing method is not high enough, and it is necessary to explore a new focusing method and device

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