Automatic focusing device

Abstract

The invention discloses an automatic focusing device which comprises the components of a transmitting module which comprises a light source; a reflecting module which comprises a reflector, wherein the edge of the reflector is tangential with the optical axis of the light source and is used for generating a semicircular eccentric light beam; a collimating mirror module which comprises a collimating lens that is mounted in an optical path between the reflector and an object lens, wherein the central axis of the collimating lens is superposed with the optical axis of the object lens, and the light source is superposed with the reflecting focus of the collimating lens; and a receiving module which comprises a photoelectric sensor, a signal processing circuit and a signal output end. Accordingto the automatic focusing device, through making the edge of the reflector be tangential with the optical axis of the light source, a fact that the light source and the photoelectric sensor are at the focus of the collimating lens is ingeniously realized, thereby simplifying optical path design, reducing hardware cost and improving accuracy. Furthermore, according to the automatic focusing device, through performing processing operation on the reflected light of measuring light, a defocus amount is calculated and furthermore the position of the object lens is quickly adjusted, thereby reducing time required for focusing and improving speed and precision in automatic focusing.

Description

technical field [0001] The invention relates to microscopic imaging technology, in particular to an automatic focusing device for a gene sequencer or a microscope. Background technique [0002] With the development of biotechnology, the requirements for microscopic imaging are getting higher and higher, and the target needs to be scanned and imaged. However, the depth of field of the objective lens with high magnification and large numerical aperture is very small, usually only a few microns, and the fluctuation of the sample surface has a great influence on the imaging, so a fast and high-precision real-time autofocus device is required. [0003] At present, the autofocus methods used in microscopes and gene sequencers are roughly divided into two types. One is to use image analysis methods to find the best focal plane. This method requires post-image processing. The disadvantage is that it is slow, and the cost of hardware and algorithms is high. , unable to focus in real...

AI Technical Summary

Problems solved by technology

However, the depth of field of the objective lens with high magnification and large numerical aperture is very small, usually only a few microns, and the fluctuation of the sample surface has a great impact on imaging, so a fast and high-precision real-time autofocus device is required

[0003] At present, the autofocus methods used in microscopes and gene sequencers are roughly divided into two types. One is to use image analysis methods to find the best focal plane. This method requires post-image processing. The disadvantage is that it is slow, and the cost of hardware and algorithms is high. , unable to focus in real time

Especially for gene sequencers, the chip has quenching properties, and it is not possible to take multiple pictures; the other is to use laser triangulation ranging method, the disadvantage of which is low accuracy

[0004] In the prior art, there is a focusing method that uses different algorithms to post-process the images after collecting multiple images, and then determines the position of the focal plane. Defocus amount detection device and method", invention patent with application number 201510330496.3 "Autofocus microscope and focusing method based on eccentric beam method" and invention patent with application number 201410183535.7 "Autofocus method and device for microscope", The disadvantages of the above three methods are high cost, slow speed, and inability to focus in real time

[0005] Another focusing method in the prior art is to measure and calculate the vertical distance between the objective lens and the sample by a distance measuring sensor to realize automatic focus adjustment. The distance sensor is located on the side of the objective lens. For high-magnification objective lenses, the working distance of the objective lens is very short, and the measuring beam cannot approach the objective lens.

This method is actually delayed focusing, and the accuracy is not high

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