CaF2-free low power flat field apochromatic metallographic microobjective

Abstract

The invention provides a CaF2-free low power flat field apochromatic metallographic microobjective, comprising lenses. The microobjective is characterized by comprising three lenses, namely a first plus lens, a second minus lens and a third plus lens, and the three lenses are coaxial. The first plus lens, the second minus lens, the third plus lens and an object plane are arranged in sequence from left to right, and the imaging is formed at infinity in opposite direction. The CaF2-free low power metallographic microobjective has the advantages of achieving the effect of flat field apochromatism, and having long operating distance, high cost performance and simple structure.

Description

technical field [0001] The invention relates to a microscope objective lens, in particular to a CaF-free 2 Low magnification plan apochromatic metallographic microscope objective. Background technique [0002] Microscopic objective lens is an important component of metallographic microscope, and its imaging quality directly affects the performance of metallographic microscope. The plan apochromatic microscope objective is the microscope objective with the best image quality and the highest grade. In order to correct axial chromatic aberration and secondary spectrum at the same time in the objective lens, the conventional method is to introduce optical crystals, such as calcium fluoride CaF 2 etc. as manufacturing materials. In recent years, some people use special glass (such as TF 3 ) to replace or partially replace CaF 2 The design and manufacture of plan apochromatic objective lenses shows superiority in reducing costs and improving manufacturability, but there are f...

AI Technical Summary

Problems solved by technology

In recent years, some people use special glass (such as TF 3 ) to replace or partially replace CaF 2 The design and manufacture of plan apochromatic objective lenses shows superiority in reducing costs and improving manufacturability, but there are few special optical materials, they are brittle, their physical and chemical properties are unstable, and large-sized materials are more difficult to obtain

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