CN212379648U - Ultra-wide angle lens - Google Patents

Abstract

The embodiment of the utility model discloses a super wide angle lens, include the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens that set gradually from the object side to the image side along the optical axis; the first lens is a meniscus plastic non-spherical lens or a glass spherical lens with negative focal power; the second lens is a meniscus plastic aspheric lens with negative focal power; the third lens is a biconcave plastic aspheric lens with negative focal power; the fourth lens is a biconvex glass spherical lens with positive focal power; the fifth lens is a biconvex plastic aspheric lens with positive focal power; the sixth lens is a biconcave plastic aspheric lens with negative focal power; the seventh lens is a biconvex plastic aspheric lens with positive focal power. The utility model can reduce the production cost, realize low distortion, low distortion and miniaturization, and can also realize the field angle of 120-175 degrees, and the F-Theta distortion is less than-12 percent.

Description

Ultra-wide angle lens

Technical Field

The embodiment of the utility model provides a relate to the optical lens technique, especially relate to a super wide angle camera lens.

Background

With the development of electronic technology and the increasing demand of lens applications, the current lens needs to have low distortion and high brightness in addition to the development of large field angle. For example, in a monitoring system, in order to capture more shot pictures and to see a wider range, ultra-wide-angle performance is required. However, the ultra-wide angle lens in the market is mostly made of glass aspheric lenses, so that the manufacturing difficulty is high and the production cost is high; in addition, the existing ultra-wide-angle lens still has imaging problems, including the defects of dead angle, poor definition and the like, especially when the field angle exceeds 120 degrees, the distortion is too large, the image after imaging is seriously deformed, and the monitoring effect is influenced.

SUMMERY OF THE UTILITY MODEL

The utility model provides a super wide angle camera lens to when realizing super wide angle, guarantee the low distortion and can well revise various aberrations, reduce the quantity of glass aspheric lens, reduce manufacturing and manufacturing cost.

In a first aspect, an embodiment of the present invention provides a super-wide angle lens, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, which are sequentially disposed from an object side to an image side along an optical axis;

the first lens is a meniscus-shaped plastic aspheric lens or a glass spherical lens with negative focal power; the second lens is a meniscus plastic aspheric lens with negative focal power; the third lens is a double-concave plastic aspheric lens with negative focal power; the fourth lens is a biconvex glass spherical lens with positive focal power; the fifth lens is a biconvex plastic aspheric lens with positive focal power; the sixth lens is a biconcave plastic aspheric lens with negative focal power; the seventh lens is a biconvex plastic aspheric lens with positive focal power.

Optionally, the aperture F # of the ultra-wide angle lens satisfies the relation: f # is more than or equal to 1.6 and less than or equal to 2.4.

Optionally, the focal length of the ultra-wide angle lens is f, and the focal lengths of the first lens to the seventh lens are f1, f2, f3, f4, f5, f6 and f7 in sequence; the focal lengths of the first lens to the seventh lens and the ultra-wide angle lens satisfy the following relational expressions:

1.05≤|f1/f|≤2.5；

3.5≤|f2/f|；

3.0≤|f3/f|；

1.3≤|f4/f|≤2.5；

|f5/f|≤1.98；

0.8≤|f6/f|≤1.7；

1.45≤|f7/f|。

optionally, the refractive index n1 of the first lens is larger than or equal to 1.5.

Optionally, a focal length f3 of the third lens and a distance TTL from a vertex of the front surface of the first lens to the image plane satisfy the relation: and | TTL/f3| is less than or equal to 2.48.

Optionally, the refractive index n4 of the fourth lens is larger than or equal to 1.8, and the Abbe number V4 of the fourth lens is larger than or equal to 25.

Optionally, the image-side radius of curvature R1 of the first lens and the image-side radius of curvature R4 of the fourth lens satisfy the relationship: R1/R4 is less than or equal to 0.45.

Optionally, a curvature radius R5 of the object-side surface of the fifth lens and a curvature radius R6 of the object-side surface of the sixth lens satisfy the relation: the absolute value of R5/R6 is more than or equal to 0.05.

Optionally, a curvature radius R7 of an image-side surface of the seventh lens satisfies the relation: the | R7| is less than or equal to 6.6.

Optionally, a central thickness CT6 of the sixth lens element on the optical axis and a central thickness CT7 of the seventh lens element on the optical axis satisfy the relationship: 0.17 is less than or equal to CT6/CT7 is less than or equal to 0.56.

The embodiment of the present invention provides a super-wide-angle lens, which includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed from an object side to an image side along an optical axis; the first lens is a meniscus-shaped plastic aspheric lens or a glass spherical lens with negative focal power; the second lens is a meniscus plastic aspheric lens with negative focal power; the third lens is a biconcave plastic aspheric lens with negative focal power; the fourth lens is a biconvex glass spherical lens with positive focal power; the fifth lens is a biconvex plastic aspheric lens with positive focal power; the sixth lens is a biconcave plastic aspheric lens with negative focal power; the seventh lens is a biconvex plastic aspheric lens with positive focal power, and realizes an ultra-wide angle lens structure of 2G5P or 1G 6P. The embodiment of the utility model provides a can realize adopting two pieces of glass lenses and 5 pieces of plastic lenses or a piece of glass lens and 6 pieces of plastic lenses to mix the super wide-angle lens that constitutes, not only can reduce the quantity of glass aspheric lens, reduce the manufacturing degree of difficulty of lens, effectively improve manufacturing cost, can also realize low distortion, miniaturized characteristic of super wide-angle lens for angle of vision 2w is in 120-175 within range, and F-Theta distortion is less than-12%, and optics total length TTL is less than 17.5mm, and can also satisfy infrared confocal, guarantee to work under-40 ℃ - +80 ℃.

Drawings

Fig. 1 is a schematic structural diagram of an ultra-wide angle lens provided in an embodiment of the present invention;

FIG. 2 is a field curvature graph of the ultra-wide angle lens of FIG. 1;

FIG. 3 is a distortion plot of the ultra-wide angle lens of FIG. 1;

FIG. 4 is a light fan diagram of the ultra-wide angle lens of FIG. 1;

FIG. 5 is an axial aberration of the ultra-wide angle lens of FIG. 1;

FIG. 6 is a vertical axis chromatic aberration of the ultra-wide angle lens of FIG. 1;

FIG. 7 is a stippled diagram of the ultra-wide angle lens of FIG. 1;

fig. 8 is a schematic structural diagram of another ultra-wide angle lens provided in an embodiment of the present invention;

FIG. 9 is a field curvature graph of the ultra-wide angle lens of FIG. 8;

FIG. 10 is a distortion plot of the ultra-wide angle lens of FIG. 8;

FIG. 11 is a light fan diagram of the ultra-wide angle lens of FIG. 8;

FIG. 12 is an axial aberration of the ultra-wide angle lens shown in FIG. 8;

FIG. 13 is a vertical axis chromatic aberration of the ultra-wide angle lens of FIG. 8;

fig. 14 is a dot diagram of the ultra-wide angle lens shown in fig. 8.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a schematic structural diagram of a super-wide-angle lens according to an embodiment of the present invention, and referring to fig. 1, the super-wide-angle lens includes a first lens element 11, a second lens element 12, a third lens element 13, a fourth lens element 14, a fifth lens element 15, a sixth lens element 16, and a seventh lens element 17, which are sequentially disposed from an object side to an image side along an optical axis;

the first lens 11 is a meniscus-shaped plastic aspheric lens or a glass spherical lens with negative focal power; the second lens 12 is a meniscus plastic aspheric lens with negative focal power; the third lens 13 is a biconcave plastic aspheric lens with negative focal power; the fourth lens 14 is a biconvex glass spherical lens with positive focal power; the fifth lens 15 is a biconvex plastic aspherical lens having positive focal power; the sixth lens 16 is a biconcave plastic aspheric lens with negative focal power; the seventh lens 17 is a biconvex plastic aspherical lens having positive optical power.

Therein, it is understood that the optical power is equal to the difference between the image-side and object-side convergence, which characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal power is, the stronger the bending ability to the light ray is, and the smaller the absolute value of the focal power is, the weaker the bending ability to the light ray is. When the focal power is positive, the refraction of the light is convergent; when the focal power is negative, the refraction of the light is divergent. In the super-wide-angle lens shown in fig. 1, the first lens 11, the second lens 12, the third lens 13, and the sixth lens 6 are negative focal power lenses, and the fourth lens 14, the fifth lens 15, and the seventh lens 17 are positive focal power lenses, so that the field angle can be increased by the first lens 11, and the on-axis aberration, the off-axis aberration, and the like can be corrected while converging and diverging the light by the other lenses, thereby improving the imaging quality and realizing a large-target-area and large-field-angle lens. Specifically, the focal powers of the first lens 11, the second lens 12 and the third lens 13 are set to be negative, which can cooperate to control the incident angle of the optical system, thereby realizing a large field angle; on the basis, the aberration of the ultra-wide-angle lens can be corrected by matching the focal powers of other lenses, so that the ultra-wide-angle lens is ensured to have higher resolving power.

On the basis, the second lens 12, the third lens 13, the fifth lens 15, the sixth lens 16 and the seventh lens 17 are arranged to be plastic aspheric lenses, the first lens 11 is arranged to be a plastic aspheric lens or a glass spherical lens, the fourth lens 14 is arranged to be a glass spherical lens, and two glass lenses and five plastic lenses or one glass lens and six plastic lenses can be used for mixing and compensating the glass lenses and the plastic lenses, so that the aspheric lenses can be manufactured through the plastic lenses, the axial chromatic aberration can be better corrected, and the day and night confocal function can be realized; the aspheric surface can be prepared by plastic, so that the manufacturing difficulty can be reduced, and the generation cost can be reduced; in addition, the first lens 11 and the fourth lens 14 which have higher imaging quality requirements adopt glass spherical lenses, so that the sensitivity of the whole ultra-wide-angle lens to temperature can be reduced, the lens can be ensured to meet stable imaging at higher or lower temperature, and the lens can be used in an environment of-40 to +80 ℃ to ensure that the resolution meets the imaging requirements. It should be noted that, the embodiment of the utility model provides an among the super wide-angle lens, the concrete shape of each lens for example first lens 11, second lens 12 adopt meniscus type, third lens 13 adopt biconcave type, and its purpose is used for under the prerequisite that focal power is confirmed, mutually supports the correction that realizes epaxial aberration and off-axis chromatic aberration better, reduces the distortion, optimizes the formation of image quality under the prerequisite that satisfies super wide-angle, guarantees the definition of formation of image.

The embodiment of the present invention provides a super-wide-angle lens, which includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed from an object side to an image side along an optical axis; the first lens is a meniscus-shaped plastic aspheric lens or a glass spherical lens with negative focal power; the second lens is a meniscus plastic aspheric lens with negative focal power; the third lens is a biconcave plastic aspheric lens with negative focal power; the fourth lens is a biconvex glass spherical lens with positive focal power; the fifth lens is a biconvex plastic aspheric lens with positive focal power; the sixth lens is a biconcave plastic aspheric lens with negative focal power; the seventh lens is a biconvex plastic aspheric lens with positive focal power, and realizes an ultra-wide angle lens structure of 2G5P or 1G 6P. The embodiment of the utility model provides a can realize adopting two pieces of glass lenses and 5 pieces of plastic lenses or a piece of glass lens and 6 pieces of plastic lenses to mix the super wide-angle lens that constitutes, not only can reduce the quantity of glass aspheric lens, reduce the manufacturing degree of difficulty of lens, effectively improve manufacturing cost, can also realize low distortion, miniaturized characteristic of super wide-angle lens for angle of vision 2w is in 120-175 within range, and F-Theta distortion is less than-12%, and optics total length TTL is less than 17.5mm, and can also satisfy infrared confocal, guarantee to work under-40 ℃ - +80 ℃.

To other lenses in this fisheye lens, the embodiment of the utility model provides a concrete implementation is still provided. With continued reference to fig. 1, in particular, the aperture F # of the ultra-wide angle lens satisfies the relation: the aperture F # is more than or equal to 1.6 and less than or equal to 2.4.

Further, the focal lengths of the first to seventh lenses and the ultra-wide angle lens may be set to satisfy the following relations:

1.05≤|f1/f|≤2.5；

3.5≤|f2/f|；

3.0≤|f3/f|；

1.3≤|f4/f|≤2.5；

|f5/f|≤1.98；

0.8≤|f6/f|≤1.7；

1.45≤|f7/f|；

the focal lengths of the first lens to the seventh lens are f1, f2, f3, f4, f5, f6 and f7 in sequence.

The first lens 11 can adjust and control the field angle of the whole hyper-optic angle lens through the focal length setting, and further, the refractive index n1 of the first lens can be set to be more than or equal to 1.5. At this time, the first lens 11 has a higher refractive index, and is made of a material with a low dispersion coefficient, so that the lens can accommodate light rays with a large angle, and an ultra-large viewing angle is realized.

The second lens 12 is used for smoothing the light emitted by the first lens 11 and relieving the magnitude value of the incident angle; and the third lens 13 is used for controlling the optical total length of the whole ultra-wide angle lens through the focal length setting, which is helpful for realizing the miniaturization of the lens. For the third lens 13, the focal length f3 of the third lens and the distance TTL from the vertex of the front surface of the first lens to the image plane can be optionally set to satisfy the relation: and | TTL/f3| is less than or equal to 2.48. At this time, the relationship between the focal length of the third lens 13 and the total optical length TTL is utilized to limit the overall proportion and the overall size of the ultra-wide-angle lens, so as to ensure that the ultra-wide-angle lens meets the size requirement during actual assembly, thereby contributing to miniaturization.

The fourth lens element 14, the fifth lens element 15, the sixth lens element 16, and the seventh lens element 17 are mainly responsible for correcting curvature of field and astigmatism. Alternatively, the refractive index n4 and the abbe number V4 of the fourth lens 14 may be set to satisfy: n4 is more than or equal to 1.8, and V4 is more than or equal to 25. In this case, the fourth lens element 14 has high dispersion and high refractive index characteristics, and can compensate for chromatic aberration and reduce the radius of curvature of the lens element, thereby contributing to correction of sensitivity of lens tolerance.

Further, the image-side surface curvature radius R1 of the first lens and the image-side surface curvature radius R4 of the fourth lens may satisfy the relation: R1/R4 is less than or equal to 0.45; the curvature radius R5 of the object side surface of the fifth lens and the curvature radius of the object side surface of the sixth lens satisfy the relation R6: R5/R6 is more than or equal to 0.05; the curvature radius R7 of the image-side surface of the seventh lens satisfies the relation: the | R7| is less than or equal to 6.6.

The curvature radiuses and the proportional relation of the first lens 11, the fourth lens 14, the fifth lens 15, the sixth lens 16 and the seventh lens 17 are reasonably limited, and the matching of the focal power among the lenses can be ensured, so that better image quality is obtained, the integral focal length of the lens is smaller, and the aperture is larger; it is also advantageous to reduce the angle of incidence of the light rays to less than or equal to 16.

When the ultra-wide-angle lens is designed, relevant parameters of each lens can be adjusted according to the requirement of the size of an actual lens, so that the size requirement during actual assembly is met. In addition to the super-wide-angle lens provided in the above embodiments, the central thickness CT6 of the sixth lens element 16 on the optical axis and the central thickness CT7 of the seventh lens element 17 on the optical axis may satisfy the following relation: 0.17 is less than or equal to CT6/CT7 is less than or equal to 0.56. At this time, by limiting the thickness ratio of the sixth lens 16 and the seventh lens 17, the lens size can be appropriately limited while the sixth lens 16 and the seventh lens 17 are ensured to perform mutual compensation and correction of aberration, which contributes to the miniaturization of the lens.

The ultra-wide-angle lens described above will be described below with reference to two specific embodiments. As shown in fig. 1, the super-wide angle lens includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a sixth lens 16, and a seventh lens 17, which are arranged in order from an object side to an image side along an optical axis;

the first lens 11 is a meniscus type glass spherical lens with negative focal power; the second lens 12 is a meniscus plastic aspheric lens with negative focal power; the third lens 13 is a biconcave plastic aspheric lens with negative focal power; the fourth lens 14 is a biconvex glass spherical lens with positive focal power; the fifth lens 15 is a biconvex plastic aspherical lens having positive focal power; the sixth lens 16 is a biconcave plastic aspheric lens with negative focal power; the seventh lens 17 is a biconvex plastic aspherical lens having positive optical power.

In this embodiment, among others, the respective design values of the first lens 11 to the seventh lens 17 are shown in table 1 below.

Table 1 shows a design value (F2.6 mm; F #2.0) of the ultra-wide-angle lens:

number of noodles	Surface type	Radius of curvature	Thickness of	Refractive index	Coefficient of fit cone K
						S1	Standard noodle	23.8	0.6	1.816
S2	Standard noodle	3.26	1.46
						S3	Aspherical surface	6.58	0.6	1.53	3.90
S4	Aspherical surface	3.00	1.19		-0.50
						S5	Aspherical surface	-19.47	0.6	1.66	60.00
S6	Aspherical surface	9.55	0.02		0
						S7	Standard noodle	9.26	2.03	2.05
S8	Standard noodle	-7.92	-0.01
						Diaphragm	PL	Infinity	2.03
S10	Aspherical surface	7.02	1.55	1.53	2.62
						S11	Aspherical surface	-4.17	0.08		-9.99
S12	Aspherical surface	48.1	0.59	1.66	-154.9
						S13	Aspherical surface	2.50	0.16		-4.32
S14	Aspherical surface	4.04	2.13	1.53	-1.36
						S15	Aspherical surface	-4.36	0.87		0.55

The surface numbers in table 1 are numbered according to the surface order of the respective lenses, where "S1" represents the front surface of the first lens, "S2" represents the rear surface of the first lens, and so on; the curvature radius represents the bending degree of the surface of the lens, a positive value represents that the surface is bent to the image surface side, and a negative value represents that the surface is bent to the object surface side; the thickness represents the central axial distance from the current surface to the next surface, the refractive index represents the deflection capability of the material between the current surface and the next surface to light, the blank space represents that the current position is air, and the refractive index is 1.

The aspheric conic coefficients can be defined by the following aspheric equation, but are not limited to the following representation:

wherein Z is the axial rise of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitting sphere, and the numerical value is the reciprocal of the curvature radius; k is a fitting cone coefficient; A-G are coefficients of 4 th, 6 th, 8 th, 10 th, 12 th, 14 th and 16 th order terms of the aspheric polynomial.

The aspheric surface type parameters in this example are shown in table 2:

table 2 shows a design value of aspheric coefficients in the ultra-wide-angle lens

Number of noodles

A

B

C

D

E

F

3

1.22E-03

-1.82E-03

1.84E-04

1.23E-05

-5.46E-06

3.31E-07

4

1.00E-02

-1.53E-03

-1.05E-04

1.27E-04

2.79E-06

-4.53E-06

5

5.50E-03

-1.04E-03

2.39E-04

-5.28E-05

2.68E-05

-4.80E-06

6

2.16E-03

-2.64E-05

-7.40E-04

3.81E-04

-8.06E-05

5.96E-06

10

1.16E-03

1.39E-03

-3.75E-04

1.37E-04

-2.83E-05

2.47E-06

11

-6.73E-03

4.42E-03

-9.39E-04

1.38E-04

-2.74E-05

2.55E-06

12

-2.52E-02

6.50E-03

-6.04E-04

-2.91E-04

7.06E-05

-5.93E-06

13

-5.49E-03

7.00E-04

9.59E-05

-6.50E-05

1.26E-05

-1.10E-06

14

-7.40E-04

-3.06E-03

6.81E-04

-3.39E-05

-2.04E-06

-2.79E-09

15

1.09E-03

-4.70E-05

-3.38E-05

1.87E-05

-3.76E-06

3.98E-07

FIG. 2 is a field curvature graph of the ultra-wide angle lens of FIG. 1; FIG. 3 is a distortion plot of the ultra-wide angle lens of FIG. 1; FIG. 4 is a light fan diagram of the ultra-wide angle lens of FIG. 1; FIG. 5 is an axial aberration of the ultra-wide angle lens of FIG. 1; FIG. 6 is a vertical axis chromatic aberration of the ultra-wide angle lens of FIG. 1; fig. 7 is a dot diagram of the ultra-wide angle lens shown in fig. 1. As can be seen from fig. 2, the field curvature in the meridional direction and the sagittal direction generated by the ultra-wide-angle lens on light is ± 0.1 mm; as can be seen from fig. 3, the maximum distortion of the ultra-wide angle lens is within-12%. As can be seen from FIG. 4, the imaging ranges of different wavelengths at different angles of view are all within + -20 μm; as can be seen from FIGS. 5 and 6, the axial chromatic aberration generated by the light with different wavelengths is within + -0.02 mm, the vertical chromatic aberration is within the Airy spots, and as can be seen from FIG. 7, the radii of the Airy spots at different viewing field positions are all less than 3 μm. By the way, the embodiment of the utility model provides a super wide-angle lens not only can rectify axial aberration and vertical axis colour difference, can also reduce the distortion, realizes the optimization to the formation of image.

Fig. 8 is a schematic structural diagram of another super-wide-angle lens according to an embodiment of the present invention, and referring to fig. 8, the super-wide-angle lens includes a first lens element 11, a second lens element 12, a third lens element 13, a fourth lens element 14, a fifth lens element 15, a sixth lens element 16, and a seventh lens element 17, which are disposed in order from an object side to an image side along an optical axis;

the first lens 11 is a meniscus-shaped plastic aspherical lens with negative focal power; the second lens 12 is a meniscus plastic aspheric lens with negative focal power; the third lens 13 is a biconcave plastic aspheric lens with negative focal power; the fourth lens 14 is a biconvex glass spherical lens with positive focal power; the fifth lens 15 is a biconvex plastic aspherical lens having positive focal power; the sixth lens 16 is a biconcave plastic aspheric lens with negative focal power; the seventh lens 17 is a biconvex plastic aspherical lens having positive optical power.

In this embodiment, among others, the respective design values of the first lens 21 to the seventh lens 27 are shown in table 3 below.

Table 3 shows a design value (F2.62 mm; F #2.0) of the ultra-wide-angle lens:

the aspheric surface type parameters in this example are shown in table 4:

table 4 shows a design value of aspheric coefficients in the ultra-wide-angle lens

FIG. 9 is a field curvature graph of the ultra-wide angle lens of FIG. 8; FIG. 10 is a distortion plot of the ultra-wide angle lens of FIG. 8; FIG. 11 is a light fan diagram of the ultra-wide angle lens of FIG. 8; FIG. 12 is an axial aberration of the ultra-wide angle lens shown in FIG. 8; FIG. 13 is a vertical axis chromatic aberration of the ultra-wide angle lens of FIG. 8; FIG. 14 is a stippled diagram of the ultra-wide angle lens of FIG. 8; as can be seen from fig. 9, the field curvature in the meridional direction and the sagittal direction generated by the super-wide angle lens for the light is within ± 0.15 mm; as can be seen from fig. 10, the maximum distortion of the ultra-wide angle lens is within-12%. As can be seen from fig. 11, the imaging ranges of different wavelengths at different angles of view are within ± 20 μm; as can be seen from FIGS. 12 and 13, the axial chromatic aberration generated by the light rays with different wavelengths is within + -0.02 mm, the vertical chromatic aberration is within + -4 μm, and as can be seen from FIG. 14, the Airy spots at different viewing field positions have radii smaller than 5 μm. By the way, the embodiment of the utility model provides a super wide-angle lens not only can rectify axial aberration and vertical axis colour difference, can also reduce the distortion, realizes the optimization to the formation of image.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (10)

1. A super wide-angle lens is characterized by comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are arranged in sequence from an object side to an image side along an optical axis;

the first lens is a meniscus-shaped plastic aspheric lens or a glass spherical lens with negative focal power; the second lens is a meniscus plastic aspheric lens with negative focal power; the third lens is a double-concave plastic aspheric lens with negative focal power; the fourth lens is a biconvex glass spherical lens with positive focal power; the fifth lens is a biconvex plastic aspheric lens with positive focal power; the sixth lens is a biconcave plastic aspheric lens with negative focal power; the seventh lens is a biconvex plastic aspheric lens with positive focal power.

2. The ultra-wide angle lens of claim 1, wherein the aperture F # of the ultra-wide angle lens satisfies the relationship: f # is more than or equal to 1.6 and less than or equal to 2.4.

3. The ultra-wide angle lens of claim 2, wherein the focal lengths of the first lens to the seventh lens are f1, f2, f3, f4, f5, f6, f7 in this order; the focal lengths of the first lens to the seventh lens and the ultra-wide angle lens satisfy the following relational expressions:

1.05≤|f1/f|≤2.5；

3.5≤|f2/f|；

3.0≤|f3/f|；

1.3≤|f4/f|≤2.5；

|f5/f|≤1.98；

0.8≤|f6/f|≤1.7；

1.45≤|f7/f|。

4. the ultra-wide angle lens of claim 3, wherein the refractive index n1 of the first lens is greater than or equal to 1.5.

5. The ultra-wide angle lens of claim 3, wherein the focal length f3 of the third lens and the distance TTL from the vertex of the front surface of the first lens to the image plane satisfy the following relation: and | TTL/f3| is less than or equal to 2.48.

6. The ultra-wide angle lens of claim 3, wherein the refractive index n4 of the fourth lens is greater than or equal to 1.8, and the Abbe number V4 of the fourth lens is greater than or equal to 25.

7. The ultra-wide angle lens of claim 3, wherein the radius of curvature of the image side of the first lens, R1, and the radius of curvature of the image side of the fourth lens, R4, satisfy the relationship: R1/R4 is less than or equal to 0.45.

8. The ultra-wide angle lens of claim 3, wherein the radius of curvature R5 of the object-side surface of the fifth lens element and the radius of curvature R6 of the object-side surface of the sixth lens element satisfy the relationship: the absolute value of R5/R6 is more than or equal to 0.05.

9. The ultra-wide angle lens of claim 3, wherein the radius of curvature R7 of the image side surface of the seventh lens element satisfies the relationship: the | R7| is less than or equal to 6.6.

10. The ultra-wide angle lens of claim 3, wherein the axial center thickness CT6 of the sixth lens element and the axial center thickness CT7 of the seventh lens element satisfy the relationship: 0.17 is less than or equal to CT6/CT7 is less than or equal to 0.56.

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