CN104536124B

CN104536124B - Plan apochromatic measuring microobjective with 2* overlength working distance and without CaF2

Info

Publication number: CN104536124B
Application number: CN201410852525.8A
Authority: CN
Inventors: 萧泽新
Original assignee: Guilin University of Electronic Technology
Current assignee: Guilin University of Electronic Technology
Priority date: 2014-12-31
Filing date: 2014-12-31
Publication date: 2017-05-24
Anticipated expiration: 2034-12-31
Also published as: CN104536124A

Abstract

The invention discloses a plan apochromatic measuring microobjective with a 2* overlength working distance and without CaF2. The plan apochromatic measuring microobjective is composed of five lenses including the convex lenses and the concave lenses, the convex lenses and the concave lenses are made of optical glass materials without the CaF2 and are divided into three optical groups, and all the lenses are coaxial with the center of an object plane and sequentially comprise the first convex lens, the second concave lens, the third convex lens, the fourth concave lens, the fifth concave lens and the object plane from left to right. The object plane is imaged at an infinite distance through an optical system. The plan apochromatic measuring microobjective has the advantages that low power measuring microobjective without the CaF2 achieves the plan apochromatic effect; the oversized field of view and the overlength working distance are achieved; the overlength parfocal effect is achieved; the microobjective is made of all-photonic glass, and thus the cost performance is high.

Description

One kind is without CaF22 × SLWD flat field apochromatism measures microcobjective

Technical field

The present invention relates to microcobjective, specifically one kind is without CaF₂The metering of 2 × SLWD flat field apochromatism is aobvious Speck mirror.

Background technology

Microcobjective is the most important part of measuring microscope, and the height of its image quality directly affects measuring microscope Performance.Flat field apochromatic micro objective is as best in quality, class highest microcobjective.It is correction simultaneously in object lens Primary axial chromatic aberration and second order spectrum, traditional method are that optical crystal is introduced in the positive lens of part, such as calcirm-fluoride CaF₂Deng Used as manufacture material, but this special optical material yield is few, and more crisp, physicochemical property is unstable, and large-sized material is more difficult to Obtain.In recent years, someone uses special glass (such as TF₃) come substitute or part substitute CaF₂Manufacture and design flat field apochromatic objective Mirror, superiority is shown in reduces cost and in terms of improving manufacturability, has triggered inventor further in depth to study this work, Finally one kind is designed without CaF₂2 × SLWD flat field apochromatism measures microcobjective.It is worthy of note that, companion As modern science and technology progress, measuring technology and instrument are increasingly extensive in industrial circle application, it is desirable to measure microcobjective Operating distance is more and more long, and the microcobjective structure of metering becomes increasingly complex, and three rich companies of international famous brand Japan go with the tide of historical development, Take the lead in releasing object lens of the overlength parfocalization away from=95mm；95mm parfocalizations away from microcobjective turned into so far in the world overlength parfocalization away from New standard.This is defined makes metering microcobjective realize SLWD (such as three rich 100 ×/0.7, W.D=6mm).This Object lens be exactly inventor be based on 95mm parfocalizations away from research and development SLWD flat field apochromatism it is complete metering microcobjective it Low power objective.

The content of the invention

It is an object of the invention to provide a kind of both ultra-large vision field, overlength parfocalization away from, and cost performance it is high without CaF₂ 2× SLWD flat field apochromatism measures microcobjective.

The present invention is according to combination focal power equation φ=φ₁+φ₂- d φ₁φ₂(φ₁φ₂The light of respectively light group 1,2 is burnt Degree, d is the second interarea of light group 1 and the distance between first interarea of light group 2) can determine that positive and negative group far separates " counter take the photograph remote " type Long reach microcobjective, thus structural shape select the camera lens of close structural as initial configuration, then by contracting Put, iteration optimization, finally give as of fine quality good without CaF₂2 × SLWD flat field apochromatism measures microcobjective.

The present invention is without CaF₂2 × SLWD flat field apochromatism measures microcobjective, and CaF is free of by 5₂Light The convex lens and concavees lens that glass material is made are divided into forward and backward 2 light groups and constitute, and each lens and object plane central coaxial, from From left to right put in order for：First piece convex lens, second concave lens, the 3rd concave lens, the 4th convex lens, the 5th it is recessed Lens, object plane；Object plane is by optical system imaging in unlimited distance.

In 2 light groups, near the 1st light group of image planes be by first piece convex lens and second concave lens constitute it is double Gluing unit, adds the 3rd concavees lens of contiguity, and the 2nd light group near object plane is by the 4th convex lens and the 5th concavees lens Double gluing units of composition.

1st light group of the close image planes in 2 light groups is far separated near between the 2nd light group of object plane.

It is operating distance W.D from the 5th summit of concavees lens to the distance of object plane.

Operating distance W.D=30.93mm of the invention；

Enlargement ratio β=2 × (coordinating with f '=200mm tube lenses)；

Numerical aperture >=0.055；3.45 ° of angular aperture ＞ (image space φ 24mm)；

Focal length f '=100mm；

This object lens main performance is evaluated as follows：1. show through geometrical aberration evaluation and PTZ3 tables of data contrast tests, intuitively Ground reflects that F, c light take in 0.707 ω and intersects at a point, value of chromatism PAC=0.00033, secondary light spectrum SAC= 0.003521, the 7% of SAC ≈ 0.05mm is not corrected about, correct relatively good；The spherochromatism of three kinds of wavelength is also smaller. 2. flat field effect is also quite satisfied with：The curvature of field of thatch ten thousand (PTZ3)=- 0.002504.3. visual limiting resolution N_max=153lp/ Mm, from terms of Fig. 4, the MTF curve and MTF data values of the microcobjective, full filed MTF >=0.11, substantially proximate to perfect optics System MTF lines.4. energy shared by full filed bright spot of view-field center is up to 97%.Its advantage is：

Without CaF₂Low power measures microcobjective, reaches flat field apochromatism effect；

Ultra-large vision field, SLWD；

Cost performance is high；

Overlength parfocalization away from.

Brief description of the drawings

Fig. 1 is microcobjective structural representation of the present invention；

Fig. 2 is the geometrical aberration evaluation figure of microcobjective of the present invention；

Fig. 3 is PTZ3 tables of data of the invention；

Fig. 4 is optical transfer function MTF curve figure of the invention, table；

Fig. 5 is encircled energy distribution map of the invention

Fig. 6 three rich parfocalizations of Japan are away from=complete metering microcobjective the parameter lists of 95mm.

Specific embodiment

The invention will be further elaborated below in conjunction with the accompanying drawings.

As shown in figure 1, the present invention is without CaF₂2 × SLWD flat field apochromatism measures microcobjective, by 5 Without CaF₂The convex lens that are made of optical glass material and concavees lens be divided into 3 groups of compositions, and each lens and object plane central coaxial, Scheduling is from left to right：1, second concave lens 2 of first piece convex lens, the 3rd concave lens 3, the 4th convex lens 4, the th Five concavees lens 5, object planes 6；Object plane 6 is by optical system imaging in unlimited distance.

In 2 light groups：1st light group is the double gluing units being made up of first piece convex lens and second concave lens, plus 3rd concavees lens of upper contiguity；2nd light group is the double gluing units being made up of the 4th convex lens and the 5th concavees lens, the 1st Light group and the 2nd light groupRemote to separate, its spacing is 31.8mm.

Fig. 2 is the geometrical aberration evaluation figure of this microcobjective；Fig. 3 is the PTZ3 tables of data of this object lens；From in terms of Fig. 2 and Fig. 3, Represent that F, c take intersecting, value of chromatism PAC=0.000333 in 0.707 ω；Second order spectrum SAC=0.003521, is smaller (the 7% of about non-corrected value), 3 chromatic curve spacing are small to also reflects this point.Flat field effect is also quite satisfied with：Thatch ten thousand The curvature of field (PTZ3)=- 0.002504.From in terms of Fig. 4,3 MTF curves of visual field 5 press close to the MTF of perfect optical system, and visually Limiting resolution N_maxFull filed MTF >=0.11 during=153lp/mm.From in terms of Fig. 5, energy shared by full filed bright spot of view-field center is up to 97% (when >=83%, then wave aberration≤λ/16), it is seen that the object lens of the design are satisfactory as matter.

Compared with Japanese three rich 2 × object lens in Fig. 5, the object lens of the design except operating distance got bumper crops than three product it is slightly shorter in addition to, Remaining performance maintains an equal level with three high yield product.

Claims

1. one kind is without CaF₂2 × SLWD flat field apochromatism measures microcobjective, including lens：Be free of by 5 CaF₂The convex lens that are made of optical glass material and concavees lens be divided into forward and backward 2 light groups and constitute, and each lens and object plane center Coaxially, put in order from left to right for：First piece convex lens, second concave lens, the 3rd convex lens, the 4th concave lens, 5th concave lens, object plane；Object plane is by optical system imaging in unlimited distance；

It is characterized in that：In 2 light groups, the 1st light group near image planes is by first piece convex lens and second concavees lens group Into double gluing units, add the 3rd concavees lens of contiguity, be by the 4th convex lens and the 5th near the 2nd light group of object plane Double gluing units of concavees lens composition；

The long reach W.D=30.93mm of the object lens, enlargement ratio β=2 ×, focal length f '=100mm, numerical aperture NA= 0.055, angular aperture ω=3.45 °；Parfocalization is away from=95mm.

2. microcobjective according to claim 1, it is characterized in that：1st light group of the close image planes in 2 light groups with lean on Far separated between the 2nd light group of nearly object plane.