CN201965295U

CN201965295U - Non-CaF2 medium flat filed apochromatism metallographical microscope objective

Info

Publication number: CN201965295U
Application number: CN2010206489292U
Authority: CN
Inventors: 萧泽新; 高兴宇; 曹杰; 李鹏; 肖冉
Original assignee: Guilin University of Electronic Technology
Current assignee: Guilin University of Electronic Technology
Priority date: 2010-12-07
Filing date: 2010-12-07
Publication date: 2011-09-07
Anticipated expiration: 2020-12-07

Abstract

The utility model discloses a non-CaF2 medium flat filed apochromatism metallographical microscope objective, which comprises six convex lens and concave lens made of special non-CaF2 optical glass, all the lenses are coaxial with the center of an object plane, the sequence from right to left is as follows: the object plane, a first convex lens, a second concave lens, a third convex lens, a fourth convex lens, a fifth concave lens and a six convex lens. Imaging is at infinity. For the microscope objective, the long working distance W.D is more than 10mm, the amplification factor beta is equal to 8 multiplied to 10 multiplied, the focal length f' is equal to 20-32mm, the numerical aperture NA is more than 0.2, and the aperture angle omega is larger than 2 degrees. The utility model has the following advantages: firstly, the non-CaF2 medium flat filed apochromatism metallographical microscope objective achieves a flat filed apochromatism effect; secondly, working distance is long; thirdly, the cost performance is high; and fourthly, the structure is simple.

Description

No CaF 2In times flat field apochromatism metallography microscope object lens

Technical field

The utility model relates to microcobjective, particularly a kind of no CaF ₂In times flat field apochromatism metallography microscope object lens.

Background technology

Microcobjective is the most important parts of metaloscope, and the height of its image quality directly influences the performance of metaloscope.The flat field apochromatic micro objective is the microcobjective that picture element is best, class is the highest.For proofreading and correct elementary axial chromatic aberration and second order spectrum simultaneously, conventional way is to introduce the optical crystal of low-refraction, low chromatic dispersion in the part positive lens, as calcium fluoride (CaF in object lens ₂) wait as manufactured materials, but will make that like this manufacturing cost increases greatly.Consider manufacturing cost and manufacturability, in recent years, use special glass (as TF3) to substitute or partly substitute CaF2 to manufacture and design the flat field apochromatic objective, shown superiority aspect the manufacturability reducing cost and improve.But this special optical material yield is few, more crisp, physicochemical property is unstable, and large-sized material more is difficult to obtain.The German Lycra object lens of external like product are made up of 7 lens, and object lens are made up of 6 lens, have wherein all adopted CaF ₂Material, so price is higher, and also this two object lens operating distance is also little.

The utility model content

The purpose of this utility model is to provide a kind of high performance-price ratio, no CaF simple in structure ₂In times flat field apochromatism metallography microscope object lens, can proofread and correct the axial elementary aberration of C light (656.3nm), F light (486.1nm) and the second order spectrum of d light (587.6nm) simultaneously.

The utility model is realized by following know-why: according to combined light focal power formula φ=φ ₁+ φ ₂-d φ ₁φ ₂(φ ₁, φ ₂Be respectively

light group

1,2 focal powers, d is the distance between first interarea of second interarea of light group 1 and light group 2) as can be known, in doubly flat field apochromatic micro objective can be by two low powers the combination of flat field apochromatic micro objective carry out complicated the structure, by the suitable focal length convergent-divergent and the optimization of aberration, finally obtain picture element good in times flat field apochromatic micro objective.

The utility model does not have CaF ₂In times flat field apochromatism metallography microscope object lens, do not contain CaF by 6 ₂The convex lens of optical glass and concavees lens form, put in order from right to left and be object plane → first convex lens → second concavees lens → 3rd convex lens → the 4th convex lens → 5th concave lens → the 6th convex lens, and each lens is coaxial with the object plane center, and object plane is imaged on unlimited distance after system.Distance from the summit of first convex lens to object plane is operating distance W.D.

With two low power flat field apochromatism metallography microscope object lens is initial configuration, use OSLO optical design CAD software, by the focal length convergent-divergent, optimize " r; d; and n (r: lens radius, d: lens thickness, n: the index of refraction in lens) " textural element to be to reach the requirement of flat field apochromatism, designed times infinity image distance flat field apochromatism metallography microscope object lens among the no CaF2.

Operating distance W.D of the present utility model＞10mm;

Enlargement ratio β=8 *～10 *;

Numerical aperture NA＞0.2;

Aperture angle＞2 °;

Focal distance f '=20mm～32mm.

The utility model has the advantages that:

1, do not contain CaF ₂In times metallography microscope object lens, reach flat field apochromatism effect;

2, long reach;

3, cost performance height;

4, simple in structure.

Description of drawings:

Fig. 1 is a times flat field apochromatic micro objective structural drawing in the Lycra;

Fig. 2 is a times flat field apochromatic micro objective structural drawing in the Olympus;

Fig. 3 is the utility model microcobjective structural drawing;

Fig. 4 is a geometrical aberration curve map of the present utility model;

Fig. 5 is a geometrical aberration tables of data of the present utility model.

Embodiment

As shown in Figure 3, the utility model does not have CaF ₂In times flat field apochromatism metallography microscope object lens, do not contain CaF by 6 ₂Convex lens that the optical glass of material is made and concavees lens arranged in co-axial alignment are formed, put in order and be: object plane 1, first convex lens 2, second concave lens 3, the 3rd convex lens 4, the 4th convex lens 5, the 5th concavees lens 6, the 6th convex lens 7, and each lens is coaxial with the object plane center, and imaging is at infinity after said system for object plane.

The objective lens design Aberration Analysis that the utility model provides is seen accompanying drawing 4, and accompanying drawing 5 is PTZ3 tables of data of these object lens.Fig. 4 reflects that intuitively C, d, F light intersect on 0.707 aperture band, the spherochromatism of three kinds of wavelength is very little, has reached apochromatic requirement fully; Show three a rank thatch ten thousand curvature of field (PTZ3)=-0.001778 among Fig. 5, the flat field effect is also quite satisfied.All things considered the utility model flat field apochromatism effect is fine, and picture element is better than having reached the level of international advanced person's like product with homemade flat field half apochromatic micro objective of multiplying power.

Claims

1. no CaF ₂In times flat field apochromatism metallography microscope object lens, comprise lens, it is characterized in that: form by 6 convex lens, concavees lens that do not contain the optical glass of CaF2 material, and each lens is coaxial with the object plane center, and ordering from right to left is: object plane, first convex lens, second concave lens, the 3rd convex lens, the 4th convex lens, the 5th concavees lens, the 6th convex lens.

2. no CaF according to claim 1 ₂In times flat field apochromatism metallography microscope object lens, it is characterized in that: the long reach W.D＞10mm of these object lens, enlargement ratio β=8 *～10 *, focal distance f '=20～32mm, numerical aperture NA＞0.2, aperture angle ω＞2 °.