Laser-type automatic focusing device and focusing method thereof

Abstract

The invention provides a laser-type automatic focusing device comprising a laser transmitter, a raster lens, a focusing mirror, a reflector, an objective lens, an image acquisition device and an image processing device. Laser which is emitted by the laser transmitter is filtered with the raster lens, rest laser passes through the focusing mirror to form parallel light, and the parallel light is reflected through the reflector, focused on a measured object through the objective lens capable of automatically adjusting the position, reflected back in a path symmetric with the reflecting and focusing path and finally transmitted to the image acquisition device by the raster lens to process acquired information. The automatic focusing device provided by the invention shortens the focusing time and improves the focusing accuracy. The focusing method provided by the invention can rapidly judge a defocusing state, controls a motor unidirectionally and lessens the work of processing a great deal of image information so as to greatly shorten focusing time without weakening focusing accuracy and greatly improve focusing performance.

Description

technical field [0001] The invention belongs to the technical field of optical detection, and in particular relates to a laser type automatic focusing device and a focusing method thereof. Background technique [0002] With the rapid development of automatic control technology and image processing technology, auto-focus technology using image processing methods has been applied in many fields, such as industrial optical inspection, medical imaging system, multimedia technology, etc. In industrial production, quality testing of precision instruments is often required, which requires quick and accurate acquisition of clear image information, and autofocus technology plays a vital role. Generally, the microscope autofocus method using the image processing method is to use the natural light to reflect the convex lens to present the entire inverted image, continuously shoot images through the camera, and continuously compare and analyze them, and repeatedly control the moving len...

AI Technical Summary

Problems solved by technology

Generally, the microscope autofocus method using the image processing method is to use the natural light to reflect the convex lens to present the entire inverted image, continuously shoot images through the camera, and continuously compare and analyze them, and repeatedly control the moving lens until the clearest image is found. Focus point criterion, however, this autofocus method needs to store and process a large amount of image information, which affects the speed of autofocus, and the accuracy of focus is not high

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