阅读说明：本技术 一种七片式广角镜头 (Seven-piece type wide-angle lens ) 是由 宋亮 葛杰 金兑映 于 2021-10-19 设计创作，主要内容包括：本发明涉及光学镜头技术领域,具体是一种七片式广角镜头,包括第一透镜、第二透镜、第三透镜、第四透镜、第五透镜、第六透镜、第七透镜；第一透镜为负光焦度,物侧表面和像侧表面的近轴区域均为凹面；第二透镜为正光焦度,物侧表面的近轴区域为凸面；第三透镜为正光焦度,物侧表面的近轴区域为凸面；第四透镜为正光焦度,像侧表面的近轴区域为凸面；第五透镜为负光焦度；第六透镜为正光焦度,像侧表面的近轴区域为凸面；第七透镜为负光焦度,像侧表面至少包含一个反曲点。本发明采用七片透镜,通过合理分配各透镜的光焦度、面型、各透镜的中心厚度以及各透镜之间的轴上间距等,使广角镜头具有超薄、小型化、广角、低敏感度、高成像等优点效果。(The invention relates to the technical field of optical lenses, in particular to a seven-piece wide-angle lens, which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens; the first lens has negative focal power, and paraxial regions of the object side surface and the image side surface are both concave; the second lens has positive focal power, and the paraxial region of the object side surface is a convex surface; the third lens has positive focal power, and the paraxial region of the object side surface is a convex surface; the fourth lens has positive focal power, and the paraxial region of the surface of the image side is a convex surface; the fifth lens has negative focal power; the sixth lens has positive focal power, and a paraxial region on the surface of the image side is a convex surface; the seventh lens has negative focal power, and the surface of the image side at least comprises an inflection point. The wide-angle lens adopts seven lenses, and has the advantages of ultrathin thickness, miniaturization, wide angle, low sensitivity, high imaging and the like by reasonably distributing the focal power, the surface type, the central thickness of each lens, the on-axis distance between each lens and the like of each lens.)

1. A seven-piece wide-angle lens is characterized in that: includes, arranged in order from an object side to an image side along an optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens;

the first lens has negative focal power, and paraxial regions of the object side surface and the image side surface are both concave;

the second lens has positive focal power, and the paraxial region of the object side surface is a convex surface;

the third lens has positive focal power, and the paraxial region of the object side surface is a convex surface;

the fourth lens has positive focal power, and the paraxial region of the surface of the image side is a convex surface;

the fifth lens has negative focal power;

the sixth lens has positive focal power, and a paraxial region on the surface of the image side is a convex surface;

the seventh lens has negative focal power, and the surface of the image side at least comprises an inflection point.

2. The seven-piece wide-angle lens according to claim 1, wherein the wide-angle lens satisfies the following conditional expressions:

(R5+R6)/(R5-R6)≥-1.25

wherein R5 and R6 are radii of curvature of the object-side surface and the image-side surface of the third lens element, respectively.

3. The seven-piece wide-angle lens according to claim 1, wherein the wide-angle lens satisfies the following conditional expressions:

SD1/IMGH<0.8

wherein SD1 is the effective aperture of the object side of the first lens, and IMGH is the image height of the wide-angle lens.

4. The seven-piece wide-angle lens according to claim 1, wherein the wide-angle lens satisfies the following conditional expressions:

∣tan(FOV)∣>1.1

wherein, the FOV is the field angle of the wide-angle lens.

5. The seven-piece wide-angle lens according to claim 1, wherein the wide-angle lens satisfies the following conditional expressions:

-1<(R9+R10)/(R9-R10)<0

wherein R9 and R10 are radii of curvature of the object-side surface and the image-side surface of the fifth lens element, respectively.

6. The seven-piece wide-angle lens according to claim 1, wherein the wide-angle lens satisfies the following conditional expressions:

-1.5<F1/F<-0.8

where F1 is the focal length of the second lens, and F is the focal length of the wide-angle lens.

Technical Field

The invention relates to the technical field of optical lenses, in particular to a seven-piece wide-angle lens.

Background

With the continuous development of portable electronic products such as smart phones, the requirements for lens shooting are higher and higher, especially the requirement for wide visual field. This requires the use of a wide-angle lens, which has a shorter focal length than a standard lens, but a wide viewing angle. With the development of technology, a lens is required to satisfy a miniaturization requirement while having a wide-angle characteristic.

Disclosure of Invention

In view of the above disadvantages and shortcomings of the prior art, the present invention provides a seven-lens wide-angle lens that satisfies the requirement of miniaturization while having wide-angle characteristics.

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

the invention provides a seven-piece wide-angle lens, which comprises the following components arranged along an optical axis from an object side to an image side in sequence: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens; the first lens has negative focal power, and paraxial regions of the object side surface and the image side surface are both concave; the second lens has positive focal power, and the paraxial region of the object side surface is a convex surface; the third lens has positive focal power, and the paraxial region of the object side surface is a convex surface; the fourth lens has positive focal power, and the paraxial region of the surface of the image side is a convex surface; the fifth lens has negative focal power; the sixth lens has positive focal power, and a paraxial region on the surface of the image side is a convex surface; the seventh lens has negative focal power, and the surface of the image side at least comprises an inflection point.

Further, the wide-angle lens satisfies the following conditional expression:

(R5+R6)/(R5-R6)≥-1.25

wherein R5 and R6 are radii of curvature of the object-side surface and the image-side surface of the third lens element, respectively. By changing the curvature radius of the object image of the third lens, the spherical aberration is reduced, and the lens sensitivity is reduced.

Further, the wide-angle lens satisfies the following conditional expression:

SD1/IMGH<0.8

wherein SD1 is the effective aperture of the object side of the first lens, and IMGH is the image height of the wide-angle lens. The lens satisfying this conditional expression has a small volume.

Further, the wide-angle lens satisfies the following conditional expression:

∣tan(FOV)∣>1.1

wherein, the FOV is the field angle of the wide-angle lens. A lens satisfying this conditional expression has a large angle of view.

Further, the wide-angle lens satisfies the following conditional expression:

-1<(R9+R10)/(R9-R10)<0

wherein R9 and R10 are radii of curvature of the object-side surface and the image-side surface of the fifth lens element, respectively. By changing the object curvature radius of the fifth lens, coma is reduced.

Further, the wide-angle lens satisfies the following conditional expression:

-1.5<F1/F<-0.8

where F1 is the focal length of the second lens, and F is the focal length of the wide-angle lens. The focal power of the first lens is controlled within a reasonable range, so that the subsequent optical lens can reasonably correct the spherical aberration contributed by the first positive lens, and the image quality of a field of view on a system axis can be better ensured.

The invention has the beneficial effects that: the wide-angle lens adopts seven lenses, and has at least one beneficial effect of ultrathin, miniaturization, wide angle, low sensitivity, high imaging quality and the like by reasonably distributing the focal power, the surface type, the central thickness of each lens, the on-axis distance between each lens and the like.

Drawings

Fig. 1 is a schematic structural view showing a wide-angle lens according to embodiment 1 of the present invention;

fig. 2 shows an astigmatic field curve of the wide-angle lens according to embodiment 1 of the present invention;

fig. 3 shows a distortion graph of the wide-angle lens of embodiment 1 of the present invention;

fig. 4 is a graph showing a contrast curve of the wide-angle lens according to embodiment 1 of the present invention;

fig. 5 is a schematic structural view showing a wide-angle lens according to embodiment 2 of the present invention;

fig. 6 shows an astigmatic field curvature diagram of a wide-angle lens according to embodiment 2 of the present invention;

fig. 7 is a distortion graph showing a wide-angle lens according to embodiment 2 of the present invention;

fig. 8 is a graph showing a relative illuminance curve of a wide-angle lens in embodiment 2 of the present invention.

In the figure: 1. a first lens; 2. a second lens; 3. a third lens; 4. a fourth lens; 5. a fifth lens; 6. a sixth lens; 7. a seventh lens; 8. a diaphragm; 9. and (3) a filter.

Detailed Description

For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail by way of specific embodiments with reference to the accompanying drawings.

Example 1

Fig. 1 shows an optical arrangement diagram of a seven-piece wide-angle lens according to embodiment 1 of the present invention. As shown in fig. 1, the present invention provides a seven-piece wide-angle lens. The wide-angle lens sequentially comprises from an object side to an image side along an optical axis: a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, and a seventh lens 7. The first lens 1 has negative focal power, and paraxial regions of the object side surface and the image side surface are both concave; the second lens 2 has positive focal power, and the paraxial region of the object side surface is a convex surface; the third lens 3 has positive focal power, and the paraxial region of the object-side surface is a convex surface; the fourth lens 4 has positive focal power, and the paraxial region of the surface of the image side is a convex surface; the fifth lens 5 has negative focal power; the sixth lens 6 has positive focal power, and the paraxial region of the image side surface is a convex surface; the seventh lens element 7 has negative power, and the image-side surface thereof includes at least one inflection point. And a diaphragm 8 is arranged between the second lens 2 and the third lens 3 to improve the imaging quality of the lens. The wide-angle lens described above may further include a filter 9 for correcting color deviation and/or a protective glass for protecting a photosensitive element located on the image plane.

The specific design parameters of the wide-angle lens in this embodiment 1 refer to the following table.

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

Watch 1 (a)

Table one (b) shows surface aspherical coefficients of the respective lenses of the optical lens of example 1.

Watch 1 (b)

Flour mark

K

A4

A6

A8

A10

A12

A14

A16

1

-9.90E+01

6.69E-02

-2.66E-02

8.73E-03

-1.98E-03

2.90E-04

-2.44E-05

0.00E+00

2

-7.56E-01

4.99E-03

5.57E-02

-4.38E-02

2.34E-02

-5.63E-03

0.00E+00

0.00E+00

3

-2.98E-01

-1.58E-01

-4.12E-02

4.46E-02

-1.12E-02

-7.47E-04

0.00E+00

0.00E+00

4

-6.11E+00

3.74E-02

-9.51E-02

1.53E-01

-9.37E-02

3.40E-02

0.00E+00

0.00E+00

5

9.98E-01

4.55E-03

5.04E-02

-1.34E-01

2.71E-01

-1.81E-01

0.00E+00

0.00E+00

6

-9.90E+01

-2.94E-01

3.05E-01

-3.06E-01

3.89E-01

-1.72E-01

0.00E+00

0.00E+00

7

2.10E+01

-3.98E-01

1.46E-01

-6.16E-01

1.55E+00

-2.61E+00

2.33E+00

-1.03E+00

8

1.11E+00

-5.88E-02

-6.93E-01

1.48E+00

-1.91E+00

1.73E+00

-1.09E+00

3.25E-01

9

3.38E+00

-7.49E-03

-4.61E-01

8.05E-01

-3.80E-01

-6.07E-01

8.04E-01

-2.76E-01

10

-4.29E-01

-1.51E-01

1.42E-01

1.16E-01

-3.63E-01

3.20E-01

-1.27E-01

1.94E-02

11

-8.57E+00

-1.80E-01

1.00E-01

8.22E-03

-4.68E-02

3.55E-02

-1.18E-02

1.32E-03

12

-3.56E+01

-2.61E-01

3.45E-01

-3.91E-01

2.84E-01

-1.23E-01

2.88E-02

-2.78E-03

13

-2.39E+00

-2.79E-01

8.14E-02

6.86E-02

-1.41E-01

1.19E-01

-5.75E-02

1.62E-02

14

-2.53E+00

-2.29E-01

1.62E-01

-8.52E-02

3.28E-02

-8.90E-03

1.63E-03

-1.89E-04

In this embodiment, specific parameters of the wide-angle lens are shown in the following table:

watch 1 (c)

According to the table one (a) and the table one (b), the lens shape and the lens attributes of the current embodiment are clearly shown.

Referring to fig. 1, which is an optical arrangement diagram of the wide-angle lens of embodiment 1, it can be seen that the close arrangement of the lenses of the lens can realize the smaller structural feature of the lens.

From the astigmatic field curves in fig. 2, it is shown more clearly that: the maximum difference value of the astigmatism S line and the T line of the lens is less than 0.1mm, and the maximum value of the field curvature is less than 0.1mm, which shows that the lens has better capability of improving the astigmatism and the field curvature.

From the distortion curve in fig. 3, it is shown more clearly that: the maximum distortion value of the lens is below 20%, which shows that the lens has good capability of improving distortion.

According to the relative illuminance curve in fig. 4, it is clearly shown that: the relative illumination of the marginal field of view of the lens is more than 20%, which indicates that the lens has better brightness ratio.

Example 2

Fig. 5 shows an optical arrangement diagram of a seven-piece wide-angle lens according to embodiment 2 of the present invention. As shown in fig. 5, the present invention provides a seven-piece wide-angle lens. The wide-angle lens sequentially comprises from an object side to an image side along an optical axis: a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, and a seventh lens 7. The first lens 1 has negative focal power, and paraxial regions of the object side surface and the image side surface are both concave; the second lens 2 has positive focal power, and the paraxial region of the object side surface is a convex surface; the third lens 3 has positive focal power, and the paraxial region of the object-side surface is a convex surface; the fourth lens 4 has positive focal power, and the paraxial region of the surface of the image side is a convex surface; the fifth lens 5 has negative focal power; the sixth lens 6 has positive focal power, and the paraxial region of the image side surface is a convex surface; the seventh lens element 7 has negative power, and the image-side surface thereof includes at least one inflection point. And a diaphragm 8 is arranged between the second lens 2 and the third lens 3 to improve the imaging quality of the lens. The wide-angle lens described above may further include a filter 9 for correcting color deviation and/or a protective glass for protecting a photosensitive element located on the image plane.

The design parameters of the wide-angle lens of embodiment 2 refer to the following table.

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

Watch two (a)

Table two (b) shows surface aspherical coefficients of the respective lenses of the optical lens of example 2.

Watch two (b)

Flour mark

K

A4

A6

A8

A10

A12

A14

A16

1

-9.90E+01

6.53E-02

-2.54E-02

8.03E-03

-1.74E-03

2.41E-04

-1.93E-05

6.72E-07

2

-7.25E-01

-1.63E-02

7.48E-02

-5.92E-02

3.01E-02

-6.50E-03

0.00E+00

0.00E+00

3

-3.13E-01

-1.57E-01

-1.11E-02

8.20E-03

8.44E-03

-4.08E-03

0.00E+00

0.00E+00

4

-9.26E+00

4.40E-02

-9.12E-02

1.18E-01

-6.17E-02

2.13E-02

0.00E+00

0.00E+00

5

7.69E-01

-2.51E-03

3.71E-02

-6.93E-02

1.42E-01

-8.31E-02

0.00E+00

0.00E+00

6

-9.90E+01

-2.61E-01

1.95E-01

-1.75E-01

4.10E-01

-2.76E-01

0.00E+00

0.00E+00

7

2.79E+01

-3.60E-01

-1.72E-02

-2.94E-01

9.09E-01

-1.20E+00

7.27E-01

-3.48E-01

8

-2.08E-01

-3.07E-02

-7.56E-01

1.47E+00

-1.56E+00

1.16E+00

-7.89E-01

3.12E-01

9

1.24E+00

6.50E-02

-7.01E-01

1.19E+00

-3.60E-01

-1.26E+00

1.42E+00

-4.56E-01

10

-4.28E-01

-6.18E-02

-1.98E-01

6.81E-01

-8.91E-01

6.14E-01

-2.20E-01

3.25E-02

11

-8.57E+00

-1.18E-01

-3.50E-02

1.55E-01

-1.53E-01

9.15E-02

-3.09E-02

4.20E-03

12

-3.56E+01

-2.89E-01

4.69E-01

-5.72E-01

4.30E-01

-1.93E-01

4.71E-02

-4.77E-03

13

-3.94E+00

-2.86E-01

1.82E-01

-9.42E-02

-3.16E-04

3.29E-02

-1.83E-02

3.70E-03

14

-3.16E+00

-1.86E-01

1.25E-01

-6.94E-02

2.88E-02

-8.42E-03

1.63E-03

-1.99E-04

In this embodiment, specific parameters of the wide-angle lens are shown in the following table:

watch two (c)

According to the second table (a) and the second table (b), the lens shape and the attributes of the lens of the current embodiment are clearly shown.

Referring to fig. 5, which is an optical arrangement diagram of the wide-angle lens of embodiment 2, it can be seen that the close arrangement of the lenses of the lens can realize the smaller structural features of the lens.

According to the astigmatic field curvature curve in fig. 6, it is clearly shown that the maximum difference between the astigmatic S line and the T line of the lens is below 0.1mm, and the maximum value of the field curvature is below about 0.1mm, which indicates that the lens has better capability of improving astigmatism and field curvature.

According to the distortion curve in fig. 7, it is clearly shown that the maximum distortion value of the lens is about 15%, which indicates that the lens has a good capability of improving distortion.

According to the relative illumination curve in fig. 8, it is clearly shown that the relative illumination of the peripheral field of view of the lens is greater than 20%, indicating that the lens has a better brightness ratio.

Although embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are illustrative and not restrictive, and that those skilled in the art may make changes, modifications, substitutions and alterations to the above embodiments without departing from the scope of the present invention.