Instrument for testing stray light of finite-conjugate-distance microscope objective and testing precision adjustment method

Abstract

The invention discloses an instrument for testing the stray light of a finite-conjugate-distance microscope objective, which comprises a light source, an imaging device, a trinocular observation device, a light filtering device, a first diaphragm, a test integrating sphere and a photomultiplier, wherein the light source is used for providing uniform light for lighting; the imaging device comprises a finite-conjugate-distance microscope objective, a tubular lens and a black body target board, the finite-conjugate-distance microscope objective and the tubular lens are used for imaging, and the black body target board is located on the front focal plane of the finite-conjugate-distance microscope objective and used for providing black spots for the finite-conjugate-distance microscope objective; the trinocular observation device comprises a half-pentagonal prism which can move upwards and downwards and is used for observing and ensuring that the positions of the black spots are correct in the process of measuring; after light emitted from the imaging device is filtered by the light filtering device, visible light wavebands are outputted; the first diaphragm is used for receiving the visible light wavebands, and selecting light for measuring in specific black spot image areas of black spots in the visible light wavebands; the test integrating sphere carries out light homogenization and attenuation on the received measuring light selected by the first diaphragm; and the photomultiplier is used for measuring the energy of the light subjected to light homogenization and attenuation by the test integrating sphere. The instrument disclosed by the invention has the advantages that stray light sources are reduced, and the accuracy of measurement is high.

Description

technical field [0001] The invention relates to the field of optical testing, more specifically, the invention relates to a stray light tester for an infinite conjugate distance microscopic objective lens and a method for adjusting test precision. Background technique [0002] At present, there are mainly two methods for measuring the stray light of the optical system, one is the black spot method (also called the surface source method), and the other is the point source method. Since the point source method uses a point-scanning method, the light must be collimated before entering the optical system, so for the central field of view, it is difficult to measure the reflection and scattering caused by the edge of the lens, the mirror frame and the lens barrel. Stray light. At the same time, for microscopic objective lenses with small aperture and large field of view, the parallel light illumination is very different from the real illumination, and the measurement results are ...

AI Technical Summary

Problems solved by technology

For low magnification and small numerical aperture microscopic objectives, the stray light tester of this microscopic objective can be well used for stray light measurement; for high magnification and large numerical aperture microscopic objectives, the stray light tester of this microscopic objective is There are certain defects, mainly for microscopic objectives with a numerical aperture greater than 1. If the blackbody target plate itself does not have scattering characteristics, it cannot guarantee that the numerical aperture of the illumination matches the numerical aperture of the objective lens; and the black-and-white contrast and Lambertian scattering characteristics must be guaranteed at the same time in the process The black body target plate is difficult to reach, which means that the device basically cannot be used for stray light measurement of microscope objectives with numerical aperture greater than 1

At the same time, the visual system composed of the spectroscopic element, reticle and eyepiece in the stray light tester of the microscopic objective lens is equivalent to a stray light source, which will affect the stray light measurement results of the microscopic objective lens

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