CN113866957A

CN113866957A - Economical two-component multi-point zoom imaging system

Info

Publication number: CN113866957A
Application number: CN202111295889.7A
Authority: CN
Inventors: 张荣曜; 范智宇; 杨樟洪; 林青
Original assignee: Xiamen Leading Optics Co Ltd
Current assignee: Xiamen Leading Optics Co Ltd
Priority date: 2021-11-03
Filing date: 2021-11-03
Publication date: 2021-12-31
Anticipated expiration: 2041-11-03
Also published as: CN113866957B

Abstract

The invention discloses an economical two-component multi-point zoom imaging system. The first lens to the seventh lens respectively comprise an object side and an image side; the first lens has a negative refractive index. Optical power; the second lens has a negative refractive power; the third lens has a positive refractive power; the first lens to the third lens are a compensation lens group, and the refractive power of the compensation lens group is negative; the fourth lens has a positive refractive power The fifth lens has a positive refractive power, the sixth lens has a negative refractive power, and the seventh lens has a positive refractive power; the fourth lens to the seventh lens is a variable power lens group, and the refractive power of the variable power lens group is positive; the optical imaging lens has only the above seven lenses with refractive power. The invention adopts seven lenses, and by arranging and designing the refractive index and surface shape of each lens, the lens has high resolution and can meet 4K high-definition imaging; at the same time, the color reproduction of the image is good, and the relative clear aperture reaches 1/1.6, can image clearly even in low light.

Description

Economical two-component multi-point zoom imaging system

Technical Field

The invention relates to the technical field of lenses, in particular to an economical two-component multi-point zoom imaging system.

Background

With the continuous progress of science and technology and the continuous development of society, in recent years, the optical imaging lens is also rapidly developed, and the optical imaging lens is widely applied to various fields such as smart phones, tablet computers, video conferences, vehicle-mounted monitoring, security monitoring, machine vision systems and the like. However, the zoom lens in the current market has many disadvantages, such as: the imaging resolution is low; the light transmission is small, and clear imaging cannot be realized at low illumination; at present, the lenses with the same specification are too much, so that the overall cost of the lens is too high; the optical TTL is too large and the volume is too large, so that the installation and the use are limited.

Disclosure of Invention

The objective of the present invention is to provide an economical two-component multi-point zoom imaging system, so as to solve at least one of the disadvantages of the existing zoom lens.

In order to achieve the purpose, the invention adopts the following technical scheme:

an economical two-element multi-point zoom imaging system sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens from an object side to an image side along an optical axis, wherein the first lens to the seventh lens respectively comprise an object side surface facing the object side and allowing imaging light rays to pass through and an image side surface facing the image side and allowing the imaging light rays to pass through;

the first lens element with negative refractive index has a convex object-side surface and a concave image-side surface; the second lens element has negative refractive index, and has a concave object-side surface and a concave image-side surface; the third lens element with positive refractive index has a convex object-side surface and a concave image-side surface; the first lens, the second lens, the third lens and the fourth lens are arranged in a same plane;

the fourth lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the fifth lens element with positive refractive index has a convex object-side surface and a convex image-side surface, the sixth lens element with negative refractive index has a concave object-side surface and a concave image-side surface, the seventh lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the fourth lens, the seventh lens and the fourth lens are zoom lens groups, and the refractive index of the zoom lens group is positive;

the optical imaging lens only has the seven lenses with the refractive index.

Preferably, the first lens and the fourth lens are glass spherical lenses, and the second lens, the third lens, the fifth lens, the sixth lens and the seventh lens are plastic aspherical lenses.

Preferably, the lens complies with the following conditional expression:

1.55＜nd1＜1.75, 1.5＜nd2＜1.6, 1.6＜nd3＜1.7,

1.4＜nd4＜1.5, 1.5＜nd5＜1.6, 1.6＜nd6＜1.7,

1.6＜nd7＜1.7,

the refractive indexes of the first lens, the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are nd1, nd2, nd3, nd4, nd5, nd6 and nd7 respectively.

Preferably, the lens complies with the following conditional expression:

50＜vd1＜70， 50＜vd2＜60， 15＜vd3＜25，

80＜vd4＜100, 50＜vd5＜60， 20＜vd6＜30，

20＜vd7＜30，

wherein vd1, vd2, vd3, vd4, vd5, vd6 and vd7 are the dispersion coefficients of the first lens, the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens respectively.

Preferably, the lens complies with the following conditional expression:

-15＜f1＜-10， -18＜f2＜-14， 20＜f3＜30，

10＜f4＜15， 9＜f5＜12， -7.5＜f6＜-6，

15＜f7＜17，

wherein f1, f2, f3, f4, f6 and f7 are focal length values of the first lens, the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens respectively.

Preferably, the lens complies with the following conditional expression: 0.8 < | fA/fB | < 1.2, wherein fA is the focal length value of the compensation lens group, and fB is the focal length value of the zoom lens group.

Preferably, the lens complies with the following conditional expression: TTL is less than 51mm, wherein TTL is the distance between the object side surface of the first lens and the imaging surface on the optical axis.

Preferably, the lens barrel further includes a diaphragm disposed between the third lens and the fourth lens.

After adopting the technical scheme, compared with the background technology, the invention has the following advantages:

1. the seven lenses are adopted along the direction from the object side to the image side, and the refractive index and the surface type of each lens are arranged, so that the MTF value is still larger than 0.2 when the spatial frequency of the lens reaches 300lp/mm, the control on a transfer function is good, the resolution is high, the lens has high resolution, and the 4K high-definition imaging can be met.

2. The invention adopts 470nm-650nm visible wide spectrum design, the later color is controlled within 3um, the color reducibility of the image is good, the blue-violet side color difference of the picture can not occur, meanwhile, the relative clear aperture reaches 1/1.6, and the image can be clearly imaged under low illumination.

3. The invention adopts a glass-plastic mixed seven-piece design and a glass-plastic mixed seven-piece design, compared with the prior nine-piece design scheme adopted by the same specification of the lens on the market, the negative focal power lens in the zoom group adopts a lens with smaller Abbe number, and the positive focal power lens adopts a lens with larger Abbe number (the maximum value exceeds 95), so that the chromatic aberration of the lens can be corrected just under the condition that a group of double cemented lenses is less than that of the traditional lens, the same index requirement of the nine-piece structure is achieved by using the seven-piece structure, and the structure of the lens is simpler while the cost of the lens is greatly reduced.

4. The TTL of the lens is less than 51mm, and compared with other zoom lenses, the TTL of the lens under the same imaging surface is shorter, so that the whole lens is small in size, compact in structure and convenient to install and use.

Drawings

FIG. 1 is a diagram of an optical path at a shortest focal length according to an embodiment;

FIG. 2 is a graph of MTF under visible light when the lens is at the shortest focal length according to the first embodiment;

FIG. 3 is a defocus graph under visible light with the lens at the shortest focal length in the first embodiment;

FIG. 4 is a graph of lateral chromatic aberration in visible light for a lens with the shortest focal length according to the first embodiment;

FIG. 5 is a diagram of the optical path at the longest focal length according to one embodiment;

FIG. 6 is a graph of MTF under visible light for the lens with the longest focal length according to one embodiment;

FIG. 7 is a defocus graph under visible light with the lens at the longest focal length in the first embodiment;

FIG. 8 is a graph of lateral chromatic aberration in visible light for the lens at the longest focal length according to one embodiment;

FIG. 9 is a diagram of an optical path of the second embodiment at the shortest focal length;

FIG. 10 is a graph of MTF under visible light for the lens with the shortest focal length according to the second embodiment;

FIG. 11 is a defocus graph under visible light with the lens at the shortest focal length in the second embodiment;

FIG. 12 is a graph of lateral chromatic aberration in visible light for the lens with the shortest focal length in the second embodiment;

FIG. 13 is a diagram of an optical path of the second embodiment at the longest focal length;

FIG. 14 is a graph of MTF under visible light for the lens of the second embodiment at the longest focal length;

FIG. 15 is a defocus graph under visible light with the lens at the longest focal length in the second embodiment;

FIG. 16 is a graph of lateral chromatic aberration in visible light for the lens with the longest focal length in the second embodiment;

FIG. 17 is a diagram showing the optical path of the third embodiment at the shortest focal length;

FIG. 18 is a graph of MTF under visible light for the lens of the third embodiment at the shortest focal length;

FIG. 19 is a defocus graph under visible light with the lens at the shortest focal length in the third embodiment;

FIG. 20 is a graph showing the lateral chromatic aberration in visible light when the lens is at the shortest focal length in the third embodiment;

FIG. 21 is a diagram showing an optical path of the third embodiment at the longest focal length;

FIG. 22 is a graph of MTF under visible light for the lens of the third embodiment at the longest focal length;

FIG. 23 is a defocus graph under visible light when the lens is at the longest focal length in the third embodiment;

fig. 24 is a graph of lateral chromatic aberration in visible light for the lens at the longest focal length in the third embodiment.

Description of reference numerals:

the lens comprises a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, a diaphragm 8 and a protective glass 9.

Detailed Description

To further illustrate the various embodiments, the invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. Those skilled in the art will appreciate still other possible embodiments and advantages of the present invention with reference to these figures. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The invention will now be further described with reference to the accompanying drawings and detailed description.

In the present specification, the term "a lens element having a positive refractive index (or a negative refractive index)" means that the paraxial refractive index of the lens element calculated by the gauss theory is positive (or negative). The term "object-side (or image-side) of a lens" is defined as the specific range of imaging light rays passing through the lens surface. The determination of the surface shape of the lens can be performed by the judgment method of a person skilled in the art, i.e., by the sign of the curvature radius (abbreviated as R value). The R value may be commonly used in optical design software, such as Zemax or CodeV. The R value is also commonly found in lens data sheets (lens sheets) of optical design software. When the R value is positive, the object side is judged to be a convex surface; and when the R value is negative, judging that the object side surface is a concave surface. On the contrary, regarding the image side surface, when the R value is positive, the image side surface is judged to be a concave surface; when the R value is negative, the image side surface is judged to be convex.

The invention discloses an economical two-component multi-point zoom imaging system, which sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens from an object side to an image side along an optical axis, wherein the first lens to the seventh lens respectively comprise an object side surface facing the object side and allowing imaging light rays to pass and an image side surface facing the image side and allowing the imaging light rays to pass;

the first lens element with negative refractive index has a convex object-side surface and a concave image-side surface; the second lens element has negative refractive index, and has a concave object-side surface and a concave image-side surface; the third lens element with positive refractive index has a convex object-side surface and a concave image-side surface; the first lens, the second lens, the third lens and the fourth lens are compensation lens groups, the refractive index of the compensation lens group is negative, and the front group continuously uses two lenses with negative refractive indexes, so that the light path can be better controlled;

the fourth lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the fifth lens element with positive refractive index has a convex object-side surface and a convex image-side surface, the sixth lens element with negative refractive index has a concave object-side surface and a concave image-side surface, the seventh lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the fourth lens, the seventh lens and the fourth lens are zoom lens groups, the refractive index of the zoom lens group is positive, the rear group uses four lenses, and three plastic aspheric lenses can better correct system aberration so that the imaging quality of the lens is good;

the optical imaging lens only has the seven lenses with the refractive index.

In the process of zooming the lens, when the lens changes from short focus to long focus, the zoom lens group moves towards the direction far away from the image surface, and the compensation lens group moves towards the direction close to the image surface, namely the zoom lens group is close to the compensation lens group; the distance between the zoom lens group and the target surface (namely the rear working distance of the lens) is the maximum at the moment.

Preferably, the first lens and the fourth lens are glass spherical lenses, the second lens, the third lens, the fifth lens, the sixth lens and the seventh lens are plastic aspheric lenses, and five plastic aspheric lenses are used in the lens, so that compared with the existing lens, the cost of the lens can be greatly reduced.

The equation for the object-side and image-side curves of an aspheric lens is given as follows:

wherein:

z: depth of the aspheric surface (the vertical distance between a point on the aspheric surface that is y from the optical axis and a tangent plane tangent to the vertex on the optical axis of the aspheric surface);

c: the curvature of the aspheric vertex (the vertex curvature);

k: cone coefficient (Conic Constant);

radial distance (radial distance);

r_n: normalized radius (normalysis radius (NRADIUS));

u：r/r_n；

a_m: mth order Q^conCoefficient (is the m)^th Q^con coefficient)；

Q_m ^con: mth order Q^conPolynomial (the m)^th Q^con polynomial)。

Preferably, the lens complies with the following conditional expression:

1.55＜nd1＜1.75, 1.5＜nd2＜1.6, 1.6＜nd3＜1.7,

1.4＜nd4＜1.5, 1.5＜nd5＜1.6, 1.6＜nd6＜1.7,

1.6＜nd7＜1.7,

Preferably, the lens complies with the following conditional expression:

50＜vd1＜70， 50＜vd2＜60， 15＜vd3＜25，

80＜vd4＜100, 50＜vd5＜60， 20＜vd6＜30，

20＜vd7＜30，

Preferably, the lens complies with the following conditional expression:

-15＜f1＜-10， -18＜f2＜-14， 20＜f3＜30，

10＜f4＜15， 9＜f5＜12， -7.5＜f6＜-6，

15＜f7＜17，

The imaging system of the present invention will be described in detail below with specific embodiments.

Example one

Referring to fig. 1, the present embodiment discloses an economical two-component multi-focal-length zoom imaging system, which includes, in order along an optical axis, a first lens element 1, a second lens element 2, a third lens element 3, a fourth lens element 4, a fifth lens element 5, a sixth lens element 6, and a seventh lens element 7 from an object side a1 to an image side a2, wherein each of the first lens element 1 to the seventh lens element 7 includes an object side surface facing the object side a1 and passing imaging light and an image side surface facing the image side a2 and passing imaging light.

The first lens element 1 has a negative refractive index, and the object-side surface and the image-side surface of the first lens element 1 are convex and concave; the second lens element 2 has a negative refractive index, and the object-side surface and the image-side surface of the second lens element 2 are concave; the third lens element 3 has a positive refractive index, and the object-side surface and the image-side surface of the third lens element 3 are convex and concave; the first lens element 1 to the third lens element 3 are compensation lens groups, and the refractive index of the compensation lens groups is negative.

The fourth lens element 4 has a positive refractive index, and the object-side surface and the image-side surface of the fourth lens element 4 are convex and convex; the fifth lens element 5 has a positive refractive index, the fifth lens element 5 has a convex object-side surface and a convex image-side surface, the sixth lens element 6 has a negative refractive index, the sixth lens element 6 has a concave object-side surface and a concave image-side surface, the seventh lens element 7 has a positive refractive index, and the seventh lens element 7 has a convex object-side surface and a convex image-side surface; the fourth lens element 4 to the seventh lens element 7 are variable power lens groups, and the refractive index of the variable power lens groups is positive.

The optical imaging lens only comprises the seven lenses with the refractive index, the first lens 1 and the fourth lens 4 are glass spherical lenses, and the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens 7 are plastic aspheric lenses. The diaphragm 8 is arranged between the third lens 3 and the fourth lens 4, the distance from the compensating lens group to the diaphragm 8 is D1, the distance from the diaphragm 8 to the variable power lens group is D2, the distance from the variable power lens group to an imaging surface is D3, and the numerical values of D1, D2 and D3 are changed along with the zooming of the system.

Detailed optical data of this embodiment are shown in table 1.

Table 1 detailed optical data of example one

For the detailed data of the aspheric parameters of the second lens element 2, the third lens element 3, the fifth lens element 5, the sixth lens element 6 and the seventh lens element 7, reference is made to the following table:

number of noodles

K

A4

A6

A8

A10

A12

A14

A16

3

1.27

2.633E-04

-2.556E-05

1.010E-06

-2.917E-08

3.947E-10

1.028E-12

-4.801E-14

4

1.38

1.687E-04

-2.042E-05

7.532E-07

-2.566E-08

4.872E-10

-2.467E-12

-1.101E-14

5

-5.75

-2.768E-05

1.009E-05

-7.111E-07

2.526E-08

-2.915E-10

-7.055E-12

1.086E-13

6

47.08

-2.494E-04

8.560E-06

-7.451E-07

4.101E-08

-1.055E-09

4.733E-12

9.779E-14

10

-19.15

8.638E-04

-1.157E-04

4.697E-06

-2.359E-07

9.253E-09

-3.451E-10

8.939E-12

11

-5.89

1.177E-03

-2.304E-04

6.566E-06

3.398E-07

-7.272E-09

-1.078E-09

4.435E-11

12

-5.29

3.106E-03

1.686E-04

-4.334E-06

1.293E-06

-9.418E-08

4.357E-09

-8.160E-11

13

15.87

-5.409E-04

4.832E-04

-6.329E-05

5.195E-06

-2.074E-07

-1.057E-08

1.075E-09

14

-12.30

-1.068E-03

2.741E-05

-6.900E-07

-6.696E-07

1.304E-07

-1.843E-08

9.142E-10

15

-15.56

-2.300E-03

8.549E-05

-6.745E-06

4.360E-08

1.331E-08

-3.118E-09

1.977E-10

In the specific embodiment, the combined focal length of the lens is 3.3-10 mm, the zoom ratio is 3, the FOV is 134-138 degrees, the TTL is less than 51mm, the relative aperture is 1/1.6-1/3.2, the imaging range is more than or equal to phi 6.6mm, and the CCD or CMOS chip is applicable to 1/2.7'.

Referring to fig. 2 and 6, it can be seen from the graphs that the MTF of the present embodiment has good control over the function, high resolution, and the MTF value of the spatial frequency 300lp/mm is still greater than 0.2 when the lens is used, so as to meet the requirement of 4K high-definition imaging. Referring to fig. 3 and fig. 7, it can be seen from the graphs that when the lens has a spatial frequency of 60lp/mm, the Through Focus MTFs are both greater than 0.8 and are very concentrated, the focal depth of the lens is larger, and the stability is better. Referring to fig. 4 and 8, it can be seen from the graphs that, in the visible 470nm-650nm wide spectrum band, the filter color is controlled within 3um, the color reproducibility of the image is good, and it is ensured that the blue-violet side color difference does not occur in the picture.

Example two

As shown in fig. 9 to 16, the surface convexo-concave shape and the refractive index of each lens of the present embodiment are substantially the same as those of the first embodiment, and the optical parameters such as the curvature radius of the surface of each lens and the thickness of the lens are different.

The detailed optical data of this embodiment are shown in table 2.

Table 2 detailed optical data of example two

number of noodles

K

A4

A6

A8

A10

A12

A14

A16

3

4.85

1.655E-04

-2.277E-05

1.001E-06

-2.929E-08

4.153E-10

1.533E-12

-6.033E-14

4

0.64

1.498E-04

-2.455E-05

7.160E-07

-2.408E-08

5.211E-10

-2.335E-12

1.344E-16

5

-2.01

6.253E-05

8.090E-06

-7.227E-07

2.459E-08

-2.924E-10

-6.236E-12

1.432E-13

6

201.22

-1.348E-04

1.107E-05

-7.278E-07

3.966E-08

-1.083E-09

5.011E-12

1.198E-13

10

-19.31

8.366E-04

-1.126E-04

4.916E-06

-2.445E-07

8.983E-09

-2.814E-10

6.874E-12

11

-5.67

1.176E-03

-2.275E-04

6.621E-06

3.227E-07

-6.572E-09

-7.150E-10

4.713E-11

12

-5.36

3.078E-03

-3.723E-04

-4.854E-06

1.294E-06

-9.322E-08

4.326E-09

-4.170E-11

13

16.00

-3.940E-04

4.658E-04

-6.422E-05

5.195E-06

-2.116E-07

-1.113E-08

1.102E-09

14

-10.83

-1.221E-03

2.232E-05

3.651E-07

-6.934E-07

1.300E-07

-1.837E-08

8.351E-10

15

-24.36

-2.389E-03

7.930E-05

-6.628E-06

8.547E-08

9.914E-09

-3.777E-09

2.162E-10

Referring to fig. 10 and 14, it can be seen from the graphs that the MTF of the present embodiment has good control over the function, high resolution, and the MTF value of the spatial frequency 300lp/mm is still greater than 0.2 when the lens is used, so as to meet the requirement of 4K high-definition imaging. Referring to fig. 11 and fig. 15, it can be seen from the graphs of defocus, that when the spatial frequency of the lens is 60lp/mm, the Through Focus MTFs are both greater than 0.8 and are very concentrated, the focal depth of the lens is larger, and the stability is better. Referring to fig. 12 and 16, it can be seen that, in the visible 470nm-650nm wide spectrum band, the filter color is controlled within 3um, the color reproducibility of the image is good, and it is ensured that the blue-violet side color difference does not occur in the picture.

EXAMPLE III

As shown in fig. 17 to 24, the surface convexo-concave shape and the refractive index of each lens of the present embodiment are substantially the same as those of the first embodiment, and the optical parameters such as the curvature radius of the surface of each lens and the thickness of the lens are different.

The detailed optical data of this embodiment are shown in table 3.

Table 3 detailed optical data of example three

number of noodles

K

A4

A6

A8

A10

A12

A14

A16

3

5.05

7.034E-05

-2.127E-05

1.016E-06

-2.901E-08

4.149E-10

1.396E-12

-6.074E-14

4

2.00

2.443E-04

-2.645E-05

6.957E-07

-2.426E-08

5.210E-10

-2.297E-12

-3.745E-15

5

0.46

2.011E-04

9.074E-06

-7.321E-07

2.443E-08

-2.936E-10

-6.274E-12

1.411E-13

6

499.88

-3.953E-05

1.561E-05

-6.751E-07

3.926E-08

-1.112E-09

4.419E-12

1.245E-13

10

-19.74

7.908E-04

-1.156E-04

4.846E-06

-2.447E-07

9.335E-09

-2.473E-10

4.012E-12

11

-6.58

1.251E-03

-2.274E-04

6.421E-06

3.134E-07

-5.734E-09

-5.376E-10

6.216E-11

12

-5.56

3.096E-03

-1.742E-04

-5.118E-06

1.268E-06

-9.463E-08

4.412E-09

-2.505E-12

13

16.47

-3.029E-04

4.639E-04

-6.506E-05

5.154E-06

-2.129E-07

-1.129E-08

1.113E-09

14

-9.90

-1.261E-03

2.013E-05

-1.663E-07

-7.077E-07

1.283E-07

-1.848E-08

7.792E-10

15

-29.63

-2.435E-03

7.762E-05

-6.601E-06

8.220E-08

4.623E-09

-4.407E-09

2.412E-10

Referring to fig. 18 and 22, it can be seen from the graphs that the MTF of the present embodiment has good control over the function, high resolution, and the MTF value of the spatial frequency 300lp/mm is still greater than 0.2 when the lens is used, so as to meet the requirement of 4K high-definition imaging. Referring to fig. 19 and 23, it can be seen from the graphs that when the lens has a spatial frequency of 60lp/mm, the Through Focus MTFs are both greater than 0.8 and are very concentrated, the focal depth of the lens is larger, and the stability is better. Referring to fig. 20 and 24, it can be seen that, in the visible 470nm-650nm wide spectrum band, the filter color is controlled within 3um, the color reproducibility of the image is good, and it is ensured that the blue-violet side color difference does not occur in the picture.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An economical two-component multi-point zoom imaging system, characterized in that it comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens along an optical axis from the object side to the image side in order a lens, a sixth lens, and a seventh lens, the first to seventh lenses each include an object side facing the object side and allowing the imaging light to pass, and an image side facing the image side and allowing the imaging light to pass;

The first lens has a negative refractive power, the object side of the first lens is convex, and the image side is concave; the second lens has a negative refractive power, and the object side of the second lens is concave and the image side is concave. The side surface is concave; the third lens has a positive refractive index, the object side of the third lens is convex, and the image side is concave; the first to third lenses are compensation lens groups, and the compensation lens group The refractive index is negative;

The fourth lens has a positive refractive power, the object side of the fourth lens is convex, and the image side is convex; the fifth lens has a positive refractive power, and the object side of the fifth lens is convex and the image side is convex. The side surface is convex, the sixth lens has a negative refractive index, the object side of the sixth lens is concave, and the image side is concave, the seventh lens has a positive refractive index, and the object side of the seventh lens is concave. The fourth lens to the seventh lens is a variable magnification lens group, and the refractive index of the variable magnification lens group is positive;

The optical imaging lens has only the above seven lenses with refractive power.

2 . The economical two-component multi-point zoom imaging system according to claim 1 , wherein the first lens and the fourth lens are glass spherical lenses, the second lens and the third lens are glass spherical lenses. 3 . , The fifth lens, the sixth lens and the seventh lens are plastic aspherical lenses.

3. A kind of economical two-component multi-point zoom imaging system as claimed in claim 1, is characterized in that, meets following conditional formula:

1.55＜nd1＜1.75, 1.5＜nd2＜1.6, 1.6＜nd3＜1.7,

1.4＜nd4＜1.5, 1.5＜nd5＜1.6, 1.6＜nd6＜1.7,

1.6＜nd7＜1.7,

Wherein, nd1, nd2, nd3, nd4, nd5, nd6, and nd7 are the refractive indices of the first lens, the second lens, the third lens, the fourth lens, the sixth lens, and the seventh lens, respectively.

4. A kind of economical two-component multi-point zoom imaging system as claimed in claim 1, is characterized in that, meets following conditional formula:

50<vd1<70, 50<vd2<60, 15<vd3<25,

80<vd4<100, 50<vd5<60, 20<vd6<30,

20<vd7<30,

Wherein, vd1, vd2, vd3, vd4, vd5, vd6, and vd7 are the dispersion coefficients of the first lens, the second lens, the third lens, the fourth lens, the sixth lens, and the seventh lens, respectively.

5. A kind of economical two-component multi-point zoom imaging system as claimed in claim 1, is characterized in that, meets following conditional formula:

-15<f1<-10, -18<f2<-14, 20<f3<30,

10<f4<15, 9<f5<12, -7.5<f6<-6,

15 < f7 < 17,

Wherein, f1, f2, f3, f4, f6, and f7 are the focal length values of the first lens, the second lens, the third lens, the fourth lens, the sixth lens, and the seventh lens, respectively.

6. An economical two-component multi-point zoom imaging system as claimed in claim 5, characterized in that it complies with the following conditional formula: 0.8<|fA/fB|<1.2, wherein fA is the value of the compensation lens group Focal length value, fB is the focal length value of the zoom lens group.

7. An economical two-component multi-point zoom imaging system as claimed in claim 1, characterized in that it complies with the following conditional formula: TTL<51mm, wherein TTL is the distance from the object side of the first lens to the imaging The distance of the face on the optical axis.

8 . The economical two-component multi-point zoom imaging system according to claim 1 , further comprising a diaphragm, wherein the diaphragm is arranged between the third lens and the fourth lens. 9 .