CN206594355U - A kind of solid-liquid mixed type apochromatism continuous magnification lens for Machine Vision Detection - Google Patents

Abstract

The utility model discloses a solid-liquid mixed type apochromatic continuous zoom lens for machine vision detection. The lens is composed of a positive lens, a negative lens and a stop surface, and each lens and stop surface are coaxial with the center of the object plane. The sequence from the object plane to the image plane is: the first positive lens, the second positive lens, the first negative lens, the third positive lens, the second negative lens, the third negative lens, the fourth positive lens, the diaphragm surface, The fourth negative lens, the fifth positive lens, the sixth positive lens, the fifth negative lens and the seventh positive lens, the distance from the apex of the first positive lens to the object plane is the working distance of the lens, and the lens consists of a solid lens and a liquid The lens structure, the lens can realize continuous zooming in the range of 75mm~85mm, realize apochromatic aberration in the whole zooming range, and have uniform and excellent imaging quality in the whole zooming process.

Description

A solid-liquid mixed apochromatic continuous zoom lens for machine vision inspection

technical field

The utility model belongs to the technical field of zoom lenses in the optical imaging technology, in particular to a solid-liquid mixed type apochromatic continuous zoom lens for machine vision detection.

Background technique

Traditional optical lenses mostly use solid materials such as optical glass or optical plastic, but these materials generally have problems such as large volume, heavy weight, and difficult processing. The liquid lens can change the radius of curvature of the liquid lens by various physical methods to achieve zooming, and has the advantages of small size, light weight, fast zooming speed, and high zooming precision. At the same time, compared with optical glass, optical liquid has a wider refractive index coverage and spectral range, and the dispersion value of some liquids is lower than that of ultra-low dispersion glass. Therefore, the combination of optical liquid and optical glass materials can reduce the size of the system. the secondary spectrum.

The traditional optical zoom is realized by adjusting the distance between the lenses, but this requires the cooperation of the corresponding mechanical zoom mechanism, and the actions of multiple components must be synchronized, which makes the lens structure complicated; at the same time, there are gaps and work wear in the mechanical transmission structure , which will lead to zoom misalignment and reduced reliability; and because the change of the distance between the lenses and the change of the focal length of the lens does not satisfy the linear relationship, it cannot achieve continuous, accurate and apochromatic zooming in the entire zoom range . The combination of optical liquid and optical glass can realize the continuous change of the focal length of the lens by controlling the continuous change of the curvature of the liquid surface, and has uniform and excellent imaging quality throughout the zooming process.

Utility model content

The purpose of the utility model is to overcome the shortcomings of the traditional zoom lens that cannot realize continuous and accurate zooming and apochromatic imaging in the entire zoom range, and provide a solid-liquid mixed type apochromatic continuous zoom lens for machine vision detection. The solid-liquid mixed type apochromatic continuous zoom lens can realize apochromatic aberration in the whole zoom range, and has uniform and excellent imaging quality in the whole zooming process.

The technical scheme that realizes the utility model purpose is:

A solid-liquid mixed type apochromatic continuous zoom lens for machine vision inspection, which is composed of a positive lens, a negative lens and a stop surface, each lens and stop surface are coaxial with the center of the object plane, and sequentially from the object plane to the image plane The order of arrangement is: first positive lens, second positive lens, first negative lens, third positive lens, second negative lens, third negative lens, fourth positive lens, diaphragm surface, fourth negative lens, fifth The positive lens, the sixth positive lens, the fifth negative lens and the seventh positive lens, the distance from the apex of the first positive lens to the object plane is the working distance of the lens.

The first positive lens, the second positive lens, the first negative lens, the second negative lens, the third negative lens, the fourth positive lens, the fourth negative lens, the sixth positive lens, the fifth negative lens and the seventh Positive lenses are solid lenses.

The third positive lens and the fifth positive lens are liquid lenses.

The second positive lens and the first negative lens form a first doublet; the third positive lens and the second negative lens form a first solid-liquid hybrid lens; the third negative lens and the fourth positive lens form a second doublet lens; the fifth positive lens and the sixth positive lens form the second solid-liquid hybrid lens; the fifth negative lens and the seventh positive lens form the third doublet lens.

The working distance of the lens is 240mm, the zoom range is 75mm-85mm, and the range of relative aperture variation according to the focal length is D/f'=0.347-0.306.

The object-side field of view of the lens changes according to the focal length, the field of view ranges from φ63mm to φ57mm, and the field of view on the image side is φ8mm.

The lens realizes the apochromatic wave band in the range of 0.4 μm to 0.7 μm.

The distance between the top of the spherical surface of the seventh positive lens and the image plane is 4 mm.

The lens realizes apochromatic aberration at three wavelengths of 0.486 μm, 0.587 μm and 0.656 μm, the residual position chromatic aberration value is less than 3 μm, and the residual secondary spectral value is less than 3 μm within the full zoom range.

The utility model has the following characteristics:

(1) The utility model is realized by combining a solid lens and a liquid lens. By controlling the continuous change of the surface curvature of a piece of liquid lens, the continuous change of the focal length of the lens is realized; by controlling the continuous change of the surface curvature of another piece of liquid lens, the image under the change of focal length is kept The surface position remains unchanged.

(2) The utility model can realize continuous zooming within the range of 75mm to 85mm;

(3) The utility model realizes apochromatic aberration in the full zoom range of 0.4 μm to 0.7 μm band, and has high imaging quality;

(4) The utility model has a larger field of view on the object side, which varies according to the focal length. The range of the field of view is φ63mm～φ57mm, and the working distance is 240mm;

(5) The utility model has uniform and excellent imaging quality in the full zoom range, and the focal color displacement range in the full zoom range is -2 μm to 3 μm.

The beneficial effects of the utility model:

The utility model is composed of a solid lens and a liquid lens. The lens can realize continuous zooming in the range of 75mm to 85mm, realize apochromatism in the whole zooming range, and have uniform and excellent imaging quality in the whole zooming process.

Description of drawings

Fig. 1 is the optical path figure of camera lens in the utility model embodiment;

Figures 2 to 12 are modulation transfer function diagrams of lenses at different focal lengths in embodiments of the present invention;

Fig. 13 is the residual chromatic aberration and secondary spectrogram of the lens under different focal lengths in the embodiment of the present invention;

Fig. 14 is a focus color shift diagram of the lens at different focal lengths in the embodiment of the present invention.

detailed description

The utility model will be further elaborated below in conjunction with the accompanying drawings and embodiments, but the utility model is not limited thereto.

Example:

As shown in Figure 1, a solid-liquid mixed type apochromatic continuous zoom lens for machine vision inspection is composed of a positive lens, a negative lens, and a stop surface. Each lens and stop surface are coaxial with the center of the object plane. The sequence from object plane to image plane is: first positive lens L1, second positive lens L2, first negative lens L3, third positive lens L4, second negative lens L5, third negative lens L6, fourth positive lens L7, diaphragm surface, fourth negative lens L8, fifth positive lens L9, sixth positive lens L10, fifth negative lens L11 and seventh positive lens L12, the distance from the apex of the first positive lens L1 to the object plane is working distance.

The first positive lens L1, the second positive lens L2, the first negative lens L3, the second negative lens L5, the third negative lens L6, the fourth positive lens L7, the fourth negative lens L8, and the sixth positive lens L10 , the fifth negative lens L11 and the seventh positive lens L12 are solid lenses.

The third positive lens L4 and the fifth positive lens L9 are liquid lenses.

The second positive lens L2 and the first negative lens L3 form the first doublet lens; the third positive lens L4 and the second negative lens L5 form the first solid-liquid hybrid lens; the third negative lens L6 and the fourth positive lens L7 forms the second doublet lens; the fifth positive lens L9 and the sixth positive lens L10 form the second solid-liquid hybrid lens; the fifth negative lens L11 and the seventh positive lens L12 form the third doublet lens.

The working distance of the lens is 240 mm, the zoom range is 75 mm to 85 mm, and the relative aperture varies from D/f'=0.347 to 0.306 according to the focal length.

The object field of view of the lens varies according to the focal length, and the object field of view ranges from φ63mm to φ57mm; the image field of view is φ8mm.

The lens realizes the apochromatic wave band in the range of 0.4 μm to 0.7 μm.

The lens realizes apochromatic aberration at three wavelengths of 0.486 μm, 0.587 μm and 0.656 μm, the residual position chromatic aberration value is less than 3 μm, and the residual secondary spectral value is less than 3 μm within the full zoom range.

The specific structural data of the lens adopting the structure of the above embodiment is shown in Table 1:

Sorting from the object plane to the image plane: the first positive lens L1 includes surfaces 1 and 2, the second positive lens L2 includes surfaces 3 and 4, the first negative lens L3 includes surfaces 4 and 5, and the third positive lens L4 is a liquid lens Contains surfaces 6, 7, second negative lens L5 contains surfaces 7, 8, third negative lens L6 contains surfaces 9, 10, fourth positive lens L7 contains surfaces 10, 11, diaphragm contains surface 12, fourth negative lens L8 Including surfaces 13, 14, the fifth positive lens L9 is a liquid lens including surfaces 15, 16, the sixth positive lens L10 includes surfaces 16, 17, the fifth negative lens L11 includes surfaces 18, 19, and the seventh positive lens L12 includes surfaces 19 , 20.

The thickness of the first positive lens L1 is 19.814 mm, the thickness of the second positive lens L2 is 10.119 mm, the thickness of the first negative lens L3 is 11.157 mm, the thickness of the third positive lens L4 is 7.857 mm, and the thickness of the second negative lens L5 is The thickness is 9.029 mm, the thickness of the third negative lens L6 is 10.428 mm, the thickness of the fourth positive lens L7 is 9.473 mm, the thickness of the fourth negative lens L8 is 1.107 mm, the thickness of the fifth positive lens L9 is 3.278 mm, and the thickness of the fourth positive lens L7 is 9.473 mm. The sixth positive lens L10 has a thickness of 1.044 mm, the fifth negative lens L11 has a thickness of 3.615 mm, and the seventh positive lens L12 has a thickness of 5.781 mm.

The distance between the first positive lens L1 and the second positive lens L2 is 9.574mm; the lens L2 and the lens L3 form the first doublet lens; the distance between the first negative lens L3 and the third positive lens L4 is 1.118mm; the third Positive lens L4 and lens L5 form the first solid-liquid hybrid lens; the distance between the second negative lens L5 and the third negative lens L6 is 1.279mm; the third negative lens L6 and the fourth positive lens L7 form the second doublet lens The distance between the fourth positive lens L7 and the stop surface is 12.31mm; the distance between the stop surface and the fourth negative lens L8 is 0.5mm; the distance between the fourth negative lens L8 and the fifth positive lens L9 is 0.512mm ; The fifth positive lens L9 and the sixth positive lens L10 form the second solid-liquid hybrid lens; the distance between the sixth positive lens L10 and the fifth negative lens L11 is 9.684mm; the fifth negative lens L11 and the seventh positive lens L12 The third doublet lens is formed; the distance between the seventh positive lens L12 and the image plane is 4 mm.

Table 1

In the embodiment using the above-mentioned structure, the values of the field of view D(1), the surface curvature R(6) of the first liquid lens, and the surface curvature R(15) of the second liquid lens according to the focal length are shown in Table 2.

Table 2

focal length 75 76 77 78 79 80 81 82 83 84 85 D(1) 63 62.4 61.8 61.2 60.6 60 59.4 58.8 58.2 57.6 57 R(6) 20.002 19.70 19.341 19.066 18.803 18.55 18.309 18.081 17.857 17.64 17.428 R(15) 12.081 12.216 12.154 12.281 12.415 12.563 12.735 12.932 13.103 13.268 13.42

As shown in Figure 2 to Figure 12, the MTF value of the full field of view in the full zoom range is above 0.1 at 100 cycles/mm; it can be seen from Figure 13 that the residual position chromatic aberration value in the full zoom range is <3 μm, and the residual secondary spectrum If the value is less than 3 μm, the residual position chromatic aberration and residual secondary spectrum are both smaller than the tolerance range of residual position chromatic aberration calculated by formula (1) of 6.64 μm; it can be seen from Figure 14 that the focus color shift range in the full zoom range is -2 μm to 3 μm .

Formula (1) is the formula for calculating the residual position chromatic aberration of the optical system, where λ is the wavelength, and the unit is μm. In the calculation, the lower limit of the apochromatic wavelength range of the lens is 0.4 μm; F=f'/D is the F number of the lens, In the calculation, the reciprocal of the maximum relative aperture value of the lens is taken.

ΔS′ _λ <2λF ² ＝2×0.4×(1/0.347) ² ＝6.64μm (1)

Described in this description is only the preferred specific embodiment of the utility model, the above embodiment is only used to illustrate the technical scheme of the utility model rather than the limitation of the utility model; Technical solutions that can be obtained through logical analysis, reasoning or limited experiments should all fall within the scope of the present utility model.

Claims (9)

1. a kind of solid-liquid mixed type apochromatism continuous magnification lens for Machine Vision Detection, it is characterised in that by just saturating Mirror, negative lens and diaphragm face composition, each lens, diaphragm face and object plane central coaxial are from object plane to image planes followed order： First positive lens, the second positive lens, the first negative lens, the 3rd positive lens, the second negative lens, the 3rd negative lens, the 4th positive lens, Diaphragm face, the 4th negative lens, the 5th positive lens, the 6th positive lens, the 5th negative lens and the 7th positive lens, the top of the first positive lens The distance of point to object plane is the operating distance of the camera lens.

2. camera lens according to claim 1, it is characterised in that described the first positive lens, the second positive lens, first negative Mirror, the second negative lens, the 3rd negative lens, the 4th positive lens, the 4th negative lens, the 6th positive lens, the 5th negative lens and the 7th are just Lens are solid lens.

3. camera lens according to claim 1, it is characterised in that the 3rd described positive lens and the 5th positive lens are that liquid is saturating Mirror.

4. camera lens according to claim 1, it is characterised in that second positive lens and the first negative lens group are into first pair Balsaming lens；3rd positive lens and the second negative lens group are into the first solid-liquid mixed type lens；3rd negative lens and the 4th positive lens Constitute the second cemented doublet；5th positive lens and the 6th positive lens groups are into the second solid-liquid mixed type lens；5th negative lens with 7th positive lens groups are into the 3rd cemented doublet.

5. camera lens according to claim 1, it is characterised in that the operating distance of the camera lens is 240mm, zooming range is 75mm ~ 85mm, relative aperture is D/f '=0.347 ~ 0.306 according to focal-distance tuning range.

6. camera lens according to claim 1, it is characterised in that the true field of the camera lens is according to focal length variations, visual field model Enclose for the mm of 63 mm ~ 57, image space is 8mm.

7. camera lens according to claim 1, it is characterised in that the camera lens realizes that apochromatic wavelength band is 0.4 μ m~0.7μm。

8. camera lens according to claim 1, it is characterised in that the 7th described positive lens sphere top and the spacing of image planes For 4mm.

9. camera lens according to claim 1, it is characterised in that the camera lens realize apochromatic wavelength for 0.486 μm, 0.587 μm and 0.656 μm of three kinds of wavelength, the remaining position value of chromatism in full zooming range<3 μm, the remaining μ of secondary light spectrum ＜ 3 m。