CN114942514A

CN114942514A - Small zoom lens

Info

Publication number: CN114942514A
Application number: CN202210721327.2A
Authority: CN
Inventors: 王迪; 王晓飞; 金兑映; 李爽
Original assignee: Liaoning Zhonglan Photoelectric Technology Co Ltd
Current assignee: Liaoning Zhonglan Photoelectric Technology Co Ltd
Priority date: 2022-06-17
Filing date: 2022-06-17
Publication date: 2022-08-26
Anticipated expiration: 2042-06-17
Also published as: CN114942514B

Abstract

The invention relates to the technical field of optical lenses, in particular to a small zoom lens. The optical lens assembly comprises a front lens group with negative focal power and a rear lens group with positive focal power in sequence from an object side to an image side along an optical axis; the front lens group comprises a first lens and a second lens from an object side to an image side in sequence; the rear lens group comprises a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens from the object side to the image side in sequence; the front lens group and the rear lens group move back and forth along the optical axis direction in the zooming process, at least one lens in the front lens group and the rear lens group is a glass lens, and the lenses in the front lens group and the rear lens group are both aspheric lenses; the lens satisfies the conditional expression: 1.2< Tefl/Wefl < 1.5; wherein Tefl is the focal length of the lens at the telephoto end, and Wefl is the focal length of the lens at the wide-angle end. The invention can make the lens have the characteristics of miniaturization, larger zoom magnification and high-quality imaging.

Description

Small zoom lens

Technical Field

The invention relates to the technical field of optical lenses, in particular to a small zoom lens.

Background

With the development of smart phones, users have higher and higher requirements on the photographing level and the photographing quality of the mobile phones. The prior art is usually through setting up a plurality of cameras, utilizes the switching between the camera to reach the effect that optics zoomed, nevertheless zooms through this kind of mode, and the effect that zooms is poor and happy, and occupation equipment space, the cost is also higher. How to consider the miniaturization and excellent zooming requirements of the lens becomes a difficult problem to be solved urgently at present.

Disclosure of Invention

In view of the above disadvantages and shortcomings of the prior art, the present invention provides a compact zoom lens, which solves the problems of poor zooming effect and large size in the prior art.

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

the embodiment of the invention provides a small zoom lens, which sequentially comprises a front lens group with negative focal power and a rear lens group with positive focal power from an object side to an image side along an optical axis; the front lens group comprises a first lens and a second lens from an object side to an image side in sequence, the first lens has negative focal power, the object side surface is a convex surface, and the image side surface is a concave surface; the second lens has positive focal power, the object side surface is a convex surface, and the image side surface is a concave surface; the rear lens group comprises a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens from the object side to the image side in sequence, wherein the third lens has positive focal power, the object side surface is a convex surface, and the image side surface is a convex surface; the fourth lens has negative focal power, the object side surface is a concave surface, and the image side surface is a concave surface; the fifth lens has positive focal power, the object side surface is a convex surface, and the image side surface is a convex surface; the sixth lens has negative focal power, the object side surface is a concave surface, and the image side surface is a convex surface; the seventh lens has negative focal power, the object side surface is a convex surface, and the image side surface is a concave surface; the front lens group and the rear lens group move back and forth along the optical axis direction in the zooming process, at least one lens in the front lens group and the rear lens group is a glass lens, and the lenses in the front lens group and the rear lens group are both aspheric lenses; the lens satisfies the conditional expression: 1.2< Tefl/Wefl < 1.5; wherein Tefl is the focal length of the lens at the telephoto end, and Wefl is the focal length of the lens at the wide-angle end.

After the condition expression is satisfied, the ratio of the focal length of the lens at the telephoto end to the focal length at the wide-angle end is controlled, so that the field angle difference of the optical system is increased, and the distortion of the optical system is reduced.

Further, the lens satisfies the following conditional expression: 0.8< Tlt/Tlw <1.0, wherein Tlt is the optical total length of the lens at the telephoto end, and Tlw is the optical total length of the lens at the wide-angle end.

After the condition expression is satisfied, the miniaturization of the optical system is favorably realized by controlling the ratio of the total optical length of the telephoto end of the lens to the total optical length of the wide-angle end.

Further, the lens satisfies the following conditional expression: 0.1< Ft-Fw <0.4, where Ft is an f-number of the fifth lens at a telephoto end, and Fw is an f-number of the fifth lens at a wide-angle end.

After the condition formula is satisfied, the definition of the optical system is improved, and the imaging quality is improved.

Further, the image side surface of the seventh lens has at least one point of inflection.

Therefore, the miniaturization of the optical system is facilitated, and the performance of the optical system is improved.

Further, the lens satisfies the following conditional expression: 2.5< | f12/f37 | 3.2, wherein f12 is the focal length of the front lens group and f37 is the focal length of the rear lens group.

After the condition formula is met, light can enter the rear lens group from the front lens group gently, and the optical system is guaranteed to have a good imaging effect.

Further, the third lens satisfies the following condition: nd3>1.5, vd3< 60.5; where nd3 is the refractive index of the third lens, and vd3 is the Abbe number of the third lens.

After the conditions are met, the chromatic aberration of the optical system is reduced, and good imaging is realized.

Further, the lens satisfies the following conditional expression: 1.3< - Δ Lt- Δ Lw | 1.5, wherein Δ Lt is the distance between the front lens group and the rear lens group on the optical axis when the lens is located at the telephoto end, and Δ Lw is the distance between the front lens group and the rear lens group on the optical axis when the lens is located at the wide-angle end.

Satisfying the above conditional expression is advantageous for increasing the difference in the angle of view of the optical system.

The invention has the beneficial effects that: the small zoom lens provided by the invention mainly comprises two groups of lenses including 7 lenses, adopts a mixed design of a glass aspheric lens and a plastic aspheric lens, and reasonably distributes parameters by matching reasonable focal power and surface type, so that the lens has the advantages of miniaturization, larger zoom magnification and high-quality imaging.

Drawings

Fig. 1 is a schematic configuration diagram at a wide angle of a compact zoom lens system according to embodiment 1 of the present invention;

fig. 2 is a schematic view showing a structure of a compact zoom lens according to embodiment 1 of the present invention in a telephoto state;

FIG. 3 is a graph showing a distortion curve at a wide angle of the compact zoom lens system according to embodiment 1 of the present invention;

fig. 4 is a graph showing distortion curves when the compact zoom lens of embodiment 1 of the present invention is in focus;

FIG. 5 is a view showing axial aberration at a wide angle of the compact zoom lens of embodiment 1 of the present invention;

fig. 6 is an axial aberration diagram in telephoto of the compact zoom lens according to embodiment 1 of the present invention;

FIG. 7 is a schematic view showing a configuration at a wide angle of a compact zoom lens system according to embodiment 2 of the present invention;

fig. 8 is a schematic view showing a structure of a compact zoom lens according to embodiment 2 of the present invention in a telephoto state;

FIG. 9 is a graph showing a distortion curve at a wide angle of the compact zoom lens system according to embodiment 2 of the present invention;

fig. 10 is a graph showing distortion in telephoto of the compact zoom lens according to embodiment 2 of the present invention;

FIG. 11 is a view showing axial aberration at a wide angle of the compact zoom lens of embodiment 2 of the present invention;

fig. 12 is an axial aberration diagram at the time of telephoto of the small zoom lens according to embodiment 2 of the present invention;

FIG. 13 is a schematic view showing a wide angle configuration of a compact zoom lens system according to embodiment 3 of the present invention;

fig. 14 is a schematic view showing a structure of a compact zoom lens according to embodiment 3 of the present invention in a telephoto state;

FIG. 15 is a graph showing a distortion curve at a wide angle in the compact zoom lens system according to embodiment 3 of the present invention;

fig. 16 is a graph showing distortion curves when the compact zoom lens of embodiment 3 of the present invention is in focus;

FIG. 17 is a view showing axial aberration at a wide angle in a compact zoom lens according to embodiment 3 of the present invention;

fig. 18 shows an axial aberration diagram in the case of a zoom lens of embodiment 3 of the present invention in a telephoto state.

In the figure: the lens system includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a first lens object side surface S1, a first lens image side surface S2, a second lens object side surface S3, a second lens image side surface S4, a third lens object side surface S5, a third lens image side surface S6, a stop S7, a fourth lens object side surface S8, a fourth lens image side surface S9, a fifth lens object side surface S10, a fifth lens image side surface S11, a sixth lens object side surface S12, a sixth lens image side surface S13, a seventh lens object side surface S14, a seventh lens filter image side surface S15, and an I8.

Detailed Description

For a better understanding of the present invention, reference will now be made in detail to the present embodiments of the invention, which are illustrated in the accompanying drawings.

Example 1

As shown in fig. 1 and 2, the present embodiment provides a compact zoom lens. The zoom lens includes, in order from an object side to an image side along an optical axis, a front lens group having negative power and a rear lens group having positive power.

The front lens group includes, in order from the object side to the image side, a first lens L1 and a second lens L2. The first lens element L1 has negative power, a convex object-side surface S1 and a concave image-side surface S2. The power of the second lens element L2 is positive, the object-side surface S3 is convex, and the image-side surface S4 is concave.

The rear lens group includes, in order from the object side to the image side, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7. The third lens element L3 has positive power, a convex object-side surface S5 and a convex image-side surface S6. The power of the fourth lens element L4 is negative, and its object-side surface S8 is concave, and its image-side surface S9 is also concave. The fifth lens element L5 has positive power, a convex object-side surface S10 and a convex image-side surface S11. The sixth lens element L6 has negative power, a concave object-side surface S12 and a convex image-side surface S13. The seventh lens element L7 has negative power, and has a convex object-side surface S14 and a concave image-side surface S15. The image-side surface of the seventh lens L7 has at least one inflection point.

The lens further includes a stop S7 and a filter I8, the stop S7 is disposed between the third lens L3 and the fourth lens L4, and the filter I8 is disposed between the seventh lens L7 and the image plane.

Specifically, the front lens group and the rear lens group move back and forth in the optical axis direction during zooming. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the sixth lens L6 and the seventh lens L7 are all plastic aspheric lenses, and the fifth lens L5 is a glass aspheric lens.

Table one (a) shows the surface type, radius of curvature, thickness, and material of each lens of the small zoom lens of embodiment 1. Wherein the unit of the radius of curvature and the thickness are both millimeters (mm).

Watch I (a)

Surface numbering	Surface name	Surface type	Radius of curvature	Thickness of	Material Property (Nd: Vd)
						0	Article surface	Spherical surface	Unlimited in size	Infinite number of elements
1	First lens	Aspherical surface	-9.547	0.298	1.545:55.987
						2		Aspherical surface	7.743	1.185
3	Second lens	Aspherical surface	3.069	0.378	1.671:19.264
						4		Aspherical surface	3.083	0.040
5	Third lens	Aspherical surface	1.962	0.646	1.545:55.987
						6		Aspherical surface	-7.146	-0.009
7	Diaphragm	Spherical surface	Infinite number of elements	0.275
						8	Fourth lens	Aspherical surface	-6.964	0.220	1.661:20.354
9		Aspherical surface	3.080	0.152
						10	Fifth lens element	Aspherical surface	3.951	0.467	1.851:40.056
11		Aspherical surface	-7.940	0.844
						12	Sixth lens element	Aspherical surface	-2.020	0.292	1.535:56.114
13		Aspherical surface	-2.176	0.651
						14	Seventh lens element	Aspherical surface	1.641	0.601	1.640:23.529
15		Aspherical surface	1.272	0.513
						16	IR	Spherical surface	Unlimited in size	0.210	BK7_SCHOTT
17		Spherical surface	Infinite number of elements	0.442
						18	Image plane	Spherical surface	Infinite number of elements	0.029

Table one (b) shows the cone coefficients K, and the higher-order coefficient coefficients a4, a6, A8, a10, a12, a14, and a16 that can be used for each aspherical mirror in example 1.

Watch 1 (b)

Surface numbering

K

A4

A6

A8

A10

A12

A14

A16

1

-4.44E+01

5.01E-02

-1.55E-02

4.06E-03

-7.52E-04

8.26E-05

-4.84E-06

1.17E-07

2

-6.90E+00

6.33E-02

-6.93E-03

-3.59E-05

1.01E-03

-1.10E-04

-3.94E-05

5.56E-06

3

-2.05E+01

7.44E-02

-5.94E-02

4.95E-02

-2.53E-02

7.31E-03

-1.18E-03

8.40E-05

4

1.43E-01

-1.20E-02

-6.61E-03

2.25E-02

-1.95E-02

7.27E-03

-1.33E-03

9.96E-05

5

1.47E+00

-1.93E-02

-2.70E-02

2.98E-02

-5.36E-02

3.76E-02

-1.07E-02

-3.27E-03

6

-9.90E+01

4.97E-03

-3.98E-02

2.77E-01

-8.23E-01

1.24E+00

-9.51E-01

2.88E-01

8

-5.88E+01

-1.02E-01

3.61E-01

-8.50E-01

1.39E+00

-1.48E+00

8.92E-01

-2.33E-01

9

-2.08E+00

-2.02E-01

4.94E-01

-8.84E-01

1.14E+00

-9.25E-01

4.33E-01

-9.05E-02

10

-5.34E+01

5.54E-03

-5.28E-02

8.32E-02

-1.06E-01

8.21E-02

-1.82E-02

-2.15E-03

11

3.63E+01

-5.63E-03

3.38E-03

-1.39E-02

9.34E-03

2.41E-03

-2.72E-03

1.96E-03

12

1.04E+00

-1.72E-01

3.47E-01

-5.31E-01

5.66E-01

-3.27E-01

9.76E-02

-1.23E-02

13

9.16E-01

-2.56E-01

3.86E-01

-3.94E-01

2.75E-01

-9.28E-02

1.01E-02

6.32E-04

14

-6.98E+00

-1.50E-01

7.52E-02

-3.28E-02

1.04E-02

-2.32E-03

3.14E-04

-2.29E-05

15

-5.11E+00

-8.39E-02

3.62E-02

-1.22E-02

2.68E-03

-3.74E-04

2.90E-05

-9.37E-07

In this embodiment 1, the specific parameters of the lens are shown in the following table:

watch 1 (c)

According to the attributes and structural features of the optical system shown in table one (a) and table one (b) and fig. 1 and 2, the lens shown in embodiment 1 has a small volume, and can realize a step zoom.

According to the distortion curves of table (c) and fig. 3 and 4 in which the lens is in the wide-angle and telephoto states, respectively, the lens shown in example 1 has a good ability to improve distortion.

The lens shown in embodiment 1 can image with high quality according to the axial aberration curves of table one (c) and fig. 5 and 6 in which the lens is in the wide angle and telephoto states, respectively.

Example 2

As shown in fig. 7 and 8, the present embodiment provides a compact zoom lens. The zoom lens includes a front lens group having negative power and a rear lens group having positive power in order from an object side to an image side along an optical axis.

The rear lens group includes, in order from the object side to the image side, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7. The third lens element L3 has positive power, a convex object-side surface S5 and a convex image-side surface S6. The power of the fourth lens element L4 is negative, and its object-side surface S8 is concave, and its image-side surface S9 is also concave. The fifth lens element L5 has positive power, a convex object-side surface S10 and a convex image-side surface S11. The sixth lens element L6 has negative power, a concave object-side surface S12 and a convex image-side surface S13. The seventh lens element L7 has negative power, a convex object-side surface S14 and a concave image-side surface S15. The image-side surface of the seventh lens L7 has at least one inflection point.

Specifically, the front lens group and the rear lens group move back and forth in the optical axis direction during zooming. The first lens L1, the second lens L2, the fourth lens L4, the sixth lens L6 and the seventh lens L7 are all plastic aspheric lenses, and the third lens L3 and the fifth lens L5 are glass aspheric lenses.

Table two (a) shows the surface type, radius of curvature, thickness, and material of each lens of the small zoom lens of embodiment 2. Wherein the unit of the radius of curvature and the thickness are both millimeters (mm).

Watch two (a)

Surface numbering	Surface name	Surface type	Radius of curvature	Thickness of	Material Property (Nd: Vd)
						0	Article surface	Spherical surface	Infinite number of elements	Infinite number of elements
1	First lens	Aspherical surface	-41.018	0.283	1.545:55.987
						2		Aspherical surface	5.022	1.357
3	Second lens	Aspherical surface	3.227	0.349	1.671:19.264
						4		Aspherical surface	3.068	0.040
5	Third lens	Aspherical surface	1.907	0.626	1.620:60.368
						6		Aspherical surface	33.568	0.038
7	Diaphragm	Spherical surface	Infinite number of elements	0.360
						8	Fourth lens	Aspherical surface	162.979	0.220	1.661:20.354
9		Aspherical surface	2.471	0.061
						10	Fifth lens element	Aspherical surface	4.090	0.525	1.851:40.056
11		Aspherical surface	-8.011	0.125
						12	Sixth lens element	Aspherical surface	-8.730	0.376	1.543:56.500
13		Aspherical surface	-4.466	0.927
						14	Seventh lens element	Aspherical surface	5.937	1.041	1.640:23.529
15		Aspherical surface	2.369	0.512
						16	IR	Spherical surface	Infinite number of elements	0.210	BK7_SCHOTT
17		Spherical surface	Infinite number of elements	0.302
						18	Image plane	Spherical surface	Infinite number of elements	0.027

Table two (b) shows the cone coefficients K, and the higher-order coefficient coefficients a4, a6, A8, a10, a12, a14, and a16 that can be used for each aspherical mirror in example 2.

Watch two (b)

Surface numbering

K

A4

A6

A8

A10

A12

A14

A16

1

9.90E+01

8.16E-02

-2.96E-02

9.56E-03

-2.20E-03

2.96E-04

-2.09E-05

6.06E-07

2

2.11E+00

9.30E-02

-1.43E-02

-7.15E-04

3.64E-03

-1.08E-03

4.81E-05

6.59E-06

3

-2.05E+01

7.49E-02

-4.81E-02

3.87E-02

-2.14E-02

7.02E-03

-1.34E-03

1.11E-04

4

1.73E-01

-4.26E-03

-4.17E-03

1.27E-02

-1.33E-02

5.51E-03

-1.14E-03

9.81E-05

5

1.48E+00

-2.40E-02

1.83E-02

-1.32E-01

2.98E-01

-3.81E-01

2.48E-01

-6.72E-02

6

-9.90E+01

6.07E-03

-4.55E-02

2.23E-01

-4.79E-01

5.50E-01

-3.17E-01

7.11E-02

8

-5.88E+01

-2.65E-01

4.77E-01

-1.16E+00

2.35E+00

-2.89E+00

1.83E+00

-4.66E-01

9

-9.62E+00

-2.90E-01

8.11E-01

-1.87E+00

2.81E+00

-2.43E+00

1.11E+00

-2.11E-01

10

-4.22E+01

-4.42E-02

3.10E-01

-7.88E-01

9.52E-01

-5.96E-01

1.95E-01

-2.71E-02

11

3.63E+01

-1.51E-01

3.26E-01

-2.90E-01

1.31E-01

-4.17E-02

1.80E-02

-3.92E-03

12

4.06E+01

-3.80E-01

5.83E-01

-2.86E-01

1.37E-01

-1.65E-01

1.11E-01

-2.62E-02

13

2.28E+00

-1.92E-01

2.45E-01

-1.28E-01

8.16E-02

-2.67E-02

-5.10E-03

2.98E-03

14

-6.98E+00

-1.60E-01

6.41E-02

-4.69E-02

3.28E-02

-1.61E-02

4.73E-03

-8.39E-04

15

-8.00E+00

-6.60E-02

2.23E-02

-6.83E-03

1.47E-03

-2.09E-04

1.65E-05

-5.37E-07

In this embodiment 2, the specific parameters of the lens are shown in the following table:

watch two (c)

According to the attributes and structural features of the optical system shown in table two (a) and table two (b) and fig. 7 and fig. 8, the lens shown in embodiment 2 has a small volume, and can realize a step zoom.

The lens shown in example 2 has a good ability to improve distortion according to distortion curves in table two (c) and fig. 9 and 10 in which the lens is in wide-angle and telephoto states, respectively.

The lens shown in embodiment 2 can image with high quality according to the axial aberration curves of table two (c) and the lens in the wide angle and telephoto states in fig. 11 and 12, respectively.

Example 3

As shown in fig. 13 and 14, the present embodiment provides a compact zoom lens. The optical lens includes, in order from an object side to an image side along an optical axis, a front lens group having negative power and a rear lens group having positive power.

Table iii (a) shows the surface type, radius of curvature, thickness, and material of each lens of the compact zoom lens of embodiment 3. Wherein the unit of the radius of curvature and the thickness are both millimeters (mm).

Watch III (a)

Table three (b) shows the cone coefficient K, and the higher-order term coefficients a4, a6, A8, a10, a12, a14, and a16, which can be used for each aspherical mirror in example 3.

Watch III (b)

Surface numbering

K

A4

A6

A8

A10

A12

A14

A16

1

9.58E+01

4.78E-02

-1.51E-02

4.27E-03

-8.76E-04

1.06E-04

-6.74E-06

1.75E-07

2

5.04E-01

6.00E-02

-1.09E-02

6.26E-03

-2.71E-03

1.30E-03

-3.27E-04

2.72E-05

3

-2.05E+01

6.90E-02

-5.12E-02

4.33E-02

-2.43E-02

8.11E-03

-1.57E-03

1.31E-04

4

6.53E-02

-9.47E-03

-3.25E-03

1.08E-02

-1.03E-02

3.92E-03

-7.64E-04

6.41E-05

5

1.71E+00

-2.43E-02

1.92E-02

-1.32E-01

2.75E-01

-3.31E-01

2.05E-01

-5.35E-02

6

-9.90E+01

2.15E-02

-4.19E-02

2.05E-01

-5.14E-01

6.68E-01

-4.44E-01

1.18E-01

8

-5.88E+01

-4.45E-02

2.24E-01

-6.13E-01

9.94E-01

-9.58E-01

4.91E-01

-1.05E-01

9

-2.57E+00

-1.70E-01

3.94E-01

-7.02E-01

8.55E-01

-6.21E-01

2.42E-01

-3.93E-02

10

-3.72E+01

9.19E-03

-2.17E-02

3.70E-02

-5.71E-02

6.46E-02

-3.10E-02

5.02E-03

11

3.63E+01

-2.15E-03

1.71E-02

-1.94E-02

2.34E-02

-1.61E-02

9.55E-03

-2.21E-03

12

1.70E+00

-1.38E-01

1.88E-01

-2.39E-01

2.71E-01

-1.56E-01

4.32E-02

-4.70E-03

13

1.62E+00

-2.29E-01

2.91E-01

-2.88E-01

2.19E-01

-8.56E-02

1.47E-02

-6.87E-04

14

-6.98E+00

-1.15E-01

-2.71E-02

7.86E-02

-6.03E-02

2.54E-02

-6.26E-03

8.35E-04

15

-3.30E+00

-1.43E-01

7.20E-02

-2.54E-02

5.82E-03

-8.35E-04

6.68E-05

-2.24E-06

In this embodiment 3, the specific parameters of the lens are shown in the following table:

watch III (c)

According to the attributes and structural features of the optical system shown in table three (a), table three (b) and fig. 13 and 14, the lens shown in embodiment 3 has a small volume, and can realize a step zoom.

The lens shown in example 3 has a good ability to improve distortion according to distortion curves in table three (c) and in fig. 15 and 16, in which the lens is in wide-angle and telephoto states, respectively.

The lens shown in embodiment 3 can image with high quality according to the axial aberration curves in table three (c) and fig. 17, 18 in which the lens is in the wide angle and telephoto states, respectively.

Claims

1. A compact zoom lens comprising, in order from an object side to an image side along an optical axis, a front lens group having negative power and a rear lens group having positive power,

the front lens group comprises a first lens and a second lens from an object side to an image side in sequence, the first lens has negative focal power, the object side surface is a convex surface, and the image side surface is a concave surface; the second lens has positive focal power, the object side surface is a convex surface, and the image side surface is a concave surface;

the rear lens group comprises a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens from the object side to the image side in sequence, wherein the third lens has positive focal power, the object side surface is a convex surface, and the image side surface is a convex surface; the fourth lens has negative focal power, the object side surface is a concave surface, and the image side surface is a concave surface; the fifth lens has positive focal power, the object side surface is a convex surface, and the image side surface is a convex surface; the sixth lens has negative focal power, the object side surface is a concave surface, and the image side surface is a convex surface; the seventh lens has negative focal power, the object side surface is a convex surface, and the image side surface is a concave surface;

the front lens group and the rear lens group move back and forth along the optical axis direction in the zooming process, at least one lens in the front lens group and the rear lens group is a glass lens, and the lenses in the front lens group and the rear lens group are both aspheric lenses;

the lens satisfies the conditional expression: 1.2< Tefl/Wefl < 1.5; wherein, Tefl is the focal length of the lens at the telephoto end, and Wefl is the focal length of the lens at the wide-angle end.

2. A miniature zoom lens according to claim 1, wherein said lens satisfies the following conditional expression: 0.8< Tlt/Tlw <1.0, wherein Tlt is the optical total length of the lens at the telephoto end, and Tlw is the optical total length of the lens at the wide-angle end.

3. A miniature zoom lens according to claim 1, wherein said lens satisfies the following conditional expression: 0.1< Ft-Fw <0.4, where Ft is an f-number of the fifth lens at a telephoto end, and Fw is an f-number of the fifth lens at a wide-angle end.

4. A compact zoom lens according to claim 1, characterized in that: the image side surface of the seventh lens is provided with at least one point of inflection.

5. A miniature zoom lens according to claim 1, wherein said lens satisfies the following conditional expression: 2.5< -f 12/f37 | 3.2, wherein f12 is the focal length of the front lens group, and f37 is the focal length of the rear lens group.

6. A miniature zoom lens according to claim 1, wherein said third lens satisfies the following condition: nd3>1.5, vd3< 60.5; where nd3 is the refractive index of the third lens, and vd3 is the Abbe number of the third lens.

7. A miniature zoom lens according to claim 1, wherein said lens satisfies the following conditional expression: 1.3< - Δ Lt- Δ Lw | 1.5, wherein Δ Lt is the distance between the front lens group and the rear lens group on the optical axis when the lens is located at the telephoto end, and Δ Lw is the distance between the front lens group and the rear lens group on the optical axis when the lens is located at the wide-angle end.