CN115128773A

CN115128773A - Fisheye lens

Info

Publication number: CN115128773A
Application number: CN202210403020.8A
Authority: CN
Inventors: 游赐天; 范智宇; 张荣曜
Original assignee: Xiamen Leading Optics Co Ltd
Current assignee: Xiamen Leading Optics Co Ltd
Priority date: 2021-12-24
Filing date: 2022-04-18
Publication date: 2022-09-30
Anticipated expiration: 2042-04-18
Also published as: CN115128773B; CN114114647A

Abstract

The invention discloses a fish-eye lens, which comprises a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens, wherein the first lens to the sixth lens respectively comprise an object side surface and an image side surface; the first lens element has a negative refractive index, the second lens element has a negative refractive index, the third lens element has a positive refractive index, the fourth lens element has a positive refractive index, the fifth lens element has a negative refractive index, and the sixth lens element has a positive refractive index, wherein the lens elements having refractive indices of the fisheye lens only have the six lens elements, and TTL is less than 5mm, wherein TTL is the distance on the optical axis from the object side surface of the first lens element to the image plane. The lens is few in number, the optical TTL is less than 5mm, the cost of the lens is lower, the integral volume is smaller, the weight is lighter, and the lens is convenient to install and use; the visible and infrared confocal performance of the lens is good, and the imaging quality can be better under the night vision condition; the distortion control is perfect, the edge deformation of the shot picture is small, and the post-stage image processing is facilitated.

Description

Fisheye lens

Technical Field

The invention relates to the technical field of lenses, in particular to a fisheye lens.

Background

The fish-eye lens is a lens with a focal length of 16mm or shorter and a visual angle close to or equal to 180 degrees, the front lens of the lens is large in diameter and is in a parabolic shape and protrudes towards the front part of the lens, and the fish-eye lens is quite similar to the fish eyes, so the fish-eye lens is commonly called as the fish-eye lens, and the fish-eye lens is widely applied to the fields of VR cameras, security monitoring, video conferences, unmanned aerial vehicles, vehicles and the like at present, so the requirements on the fish-eye lens are higher and higher.

However, the existing fisheye lens has many defects, such as too large optical TTL and too many lenses, which causes the overall cost and weight of the lens to be too high, and the installation and use of the lens have limitations; the visible and infrared confocal performance of the lens is poor, and the imaging quality under the night vision condition is poor; due to the fact that the field angle is too large, the distortion control of the edge of a common lens is poor, the shot picture has obvious deformation, and the later-stage image processing is influenced.

Disclosure of Invention

The present invention is directed to overcome the above-mentioned deficiencies of the prior art and to provide a fisheye lens.

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

a fisheye lens comprises a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens from an object side to an image side along an optical axis in sequence, wherein the first lens to the sixth 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 with negative refractive index has a concave object-side surface and a convex image-side surface;

the third lens element with positive refractive index has a concave object-side surface and a convex image-side surface;

the fourth lens element with positive refractive index has a convex object-side surface and a convex image-side surface;

the fifth lens element has a negative refractive index, and an object-side surface and an image-side surface of the fifth lens element are concave;

the sixth lens element with positive refractive index has a convex object-side surface and a convex image-side surface;

the fisheye lens has only the six lenses with the refractive index, and the TTL is less than 5mm, wherein the TTL is the distance between the object side surface of the first lens and the imaging surface on the optical axis.

Preferably, the first lens, the second lens, the third lens, the fourth lens, the sixth lens, the glass aspheric lens, and the plastic aspheric lens satisfy 2 < f456/f < 3, where f456 is a focal length of the rear lens group, and f is an overall focal length of the lens.

Preferably, the lens satisfies the following conditional expressions:

2＜|f1/f|＜3， 15.5＜|f2/f|＜17， 3＜|f3/f|＜5，

1＜|f4/f|＜3， 1＜|f5/f|＜2， 1.5＜|f6/f|＜3，

wherein f is the overall focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f6 is the focal length of the sixth lens.

Preferably, the lens satisfies the following conditional expression:

-1.9＜f1＜-1.7， -13.5＜f2＜-11， 2＜f3＜4，

0.5＜f4＜1.5， -1.5＜f5＜-0.5， 1＜f6＜2。

preferably, the lens satisfies the following conditional expressions:

1.7＜nd1＜1.9， 1.6＜nd2＜1.8， 1.5＜nd3＜1.6，

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

where nd1 is the refractive index of the first lens, nd2 is the refractive index of the second lens, nd3 is the refractive index of the third lens, nd4 is the refractive index of the fourth lens, nd5 is the refractive index of the fifth lens, and nd6 is the refractive index of the sixth lens.

Preferably, the lens satisfies the following conditional expression:

45＜vd1＜60， 18＜vd2＜25， 50＜vd3＜60，

50＜vd4＜70， 18＜vd5＜25， 50＜vd6＜60，

wherein vd1 is the abbe number of the first lens, vd2 is the abbe number of the second lens, vd3 is the abbe number of the third lens, vd4 is the abbe number of the fourth lens, vd5 is the abbe number of the fifth lens, and vd6 is the abbe number of the sixth lens.

Preferably, the lens satisfies the following conditional expressions:

5.5＜R11＜8，1.05＜R12， -2＜R21＜-1，-3＜R22＜-1.5，

-7＜R31＜-6，-2＜R32＜-1， 1＜R41＜2，-1.5＜R42＜-0.5，

-1.2＜R51＜-0.5，1.5＜R52＜3， 3＜R61＜4，-1＜R62＜-0.5，

wherein, R11 and R12 are R values of the object-side surface and the image-side surface of the first lens, R21 and R22 are R values of the object-side surface and the image-side surface of the second lens, R31 and R32 are R values of the object-side surface and the image-side surface of the third lens, R41 and R42 are R values of the object-side surface and the image-side surface of the fourth lens, R51 and R52 are R values of the object-side surface and the image-side surface of the fifth lens, and R61 and R62 are R values of the object-side surface and the image-side surface of the sixth lens, respectively.

Preferably, the ratio of the thickness of the edge of the lens to the thickness of the center of the lens of the first lens, the second lens and the fifth lens is in the range of 1.0-1.8; the ratio of the thickness of the edge of the lens to the thickness of the center of the lens of the third lens, the fourth lens and the sixth lens is in the range of 0.5-0.9.

Preferably, the lens satisfies the following conditional expressions: and ImgH/AAG is more than 3.5, wherein ImgH is the image height on the imaging surface of the system, and AAG is the sum of the air gaps between the first lens and the sixth lens.

Preferably, the lens satisfies the following conditional expressions: ALT/AAG > 3.5, where ALT is the sum of the central thicknesses of the first through sixth lenses and AAG is the sum of the air gaps between the first through sixth lenses.

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

1. the invention adopts six lenses for design, the number of the lenses is small, and the optical TTL is less than 5mm, so that the lens has the advantages of lower cost, smaller integral volume, lighter weight and convenient installation and use.

2. The central focal shift of the lens at 850nm is less than 6um, the visible and infrared confocal performance of the lens is good, and the imaging quality can be better under the night vision condition.

3. The F-Theta distortion of the invention is controlled within 2 percent, the distortion control is perfect, the edge deformation of the shot picture is small, and the invention is beneficial to the post-image processing.

Drawings

FIG. 1 is a light path diagram according to the first embodiment;

FIG. 2 is a graph of MTF of the lens in the first embodiment under the visible light of 435nm-656 nm;

FIG. 3 is a defocus graph of the lens in the first embodiment under 435-656 nm of visible light;

FIG. 4 is a graph of lateral chromatic aberration of the lens in the first embodiment under the condition of 435nm-656nm of visible light;

FIG. 5 is a graph of longitudinal chromatic aberration of the lens in the first embodiment under 435nm-656nm of visible light;

FIG. 6 is a graph of field curvature and distortion under 435-656 nm in visible light for a lens according to an embodiment;

FIG. 7 is a diagram illustrating a defocus graph of a central field of view of a lens in a near infrared light of 850nm in a first embodiment;

FIG. 8 is a light path diagram of the second embodiment;

FIG. 9 is a graph showing MTF curves of the lens in the second embodiment in the visible light range from 435nm to 656 nm;

FIG. 10 is a defocus graph of the lens in the second embodiment in the visible light range from 435nm to 656 nm;

FIG. 11 is a lateral chromatic aberration curve of the lens of the second embodiment under the visible light of 435nm-656 nm;

FIG. 12 is a graph of longitudinal chromatic aberration of the lens of the second embodiment in the visible light range from 435nm to 656 nm;

FIG. 13 is a graph of curvature of field and distortion under 435-656 nm in visible light for a lens of the second embodiment;

FIG. 14 is a defocus graph of the central field of view at 850nm near infrared for the lens of the second embodiment;

FIG. 15 is a light path diagram of the third embodiment;

FIG. 16 is a graph showing MTF curves of the lens in the third embodiment in the visible light range from 435nm to 656 nm;

FIG. 17 is a defocus graph of the lens in the third embodiment in the visible light range from 435nm to 656 nm;

FIG. 18 is a graph of lateral chromatic aberration of the lens of the third embodiment in the visible light range from 435nm to 656 nm;

FIG. 19 is a graph of longitudinal chromatic aberration of the lens of the third embodiment in the visible light range from 435nm to 656 nm;

FIG. 20 is a graph showing the field curvature and distortion of a lens in the third embodiment in the visible light range from 435nm to 656 nm;

FIG. 21 is a central field defocus graph of a lens in a third embodiment under near infrared light of 850 nm;

FIG. 22 is a light path diagram of the fourth embodiment;

FIG. 23 is a graph showing the MTF curves of the lens of the fourth embodiment in the visible light range from 435nm to 656 nm;

FIG. 24 is a graph showing the defocus curves of the lens of the fourth embodiment in the visible light range from 435nm to 656 nm;

FIG. 25 is a graph of lateral chromatic aberration of the lens of the fourth embodiment in the visible light range from 435nm to 656 nm;

FIG. 26 is a graph showing the longitudinal chromatic aberration of the lens of the fourth embodiment in the visible light range from 435nm to 656 nm;

FIG. 27 is a graph showing the field curvature and distortion of a lens in 435-656 nm in visible light according to the fourth embodiment;

FIG. 28 is a central field defocus plot at 850nm for near infrared light for the lens of the fourth embodiment;

FIG. 29 is a light path diagram of the fifth embodiment;

FIG. 30 is a graph showing MTF curves of the lens of example V at 435-656 nm in visible light;

FIG. 31 is a graph showing the defocus curves of the lens of the fifth embodiment in the visible light range from 435nm to 656 nm;

FIG. 32 is a graph of lateral chromatic aberration of the lens of the fifth embodiment in visible light 435-656 nm;

FIG. 33 is a graph showing longitudinal chromatic aberration of the lens of the fifth embodiment in visible light of 435-656 nm;

FIG. 34 is a graph showing the curvature of field and distortion of a lens in the fifth embodiment in the visible light range from 435nm to 656 nm;

FIG. 35 is a central field-of-view defocus graph of the lens of example V at 850nm near-infrared light.

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, an aperture 7 and a protective glass 8.

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 Ze max or Code V. The R value is also commonly found in lens data sheets (lens data 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 a fish-eye lens, which sequentially comprises a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens from an object side to an image side along an optical axis, wherein the first lens to the sixth 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 fifth lens element has a negative refractive index, and the object-side surface and the image-side surface of the fifth lens element are concave;

this fisheye lens has lens of refractive index and only above-mentioned six, and satisfy TTL < 5mm, wherein, TTL is the object side face to the distance of imaging surface on the optical axis of first lens, and the camera lens focus is f 0.77mm, and FOV 170, whole visual field is big, compact structure, and the practicality is strong.

Preferably, the lens satisfies the following conditional expressions:

2＜|f1/f|＜3， 15.5＜|f2/f|＜17， 3＜|f3/f|＜5，

1＜|f4/f|＜3， 1＜|f5/f|＜2， 1.5＜|f6/f|＜3，

wherein f is the overall focal length of the lens, f1 is the focal length of the first lens element, f2 is the focal length of the second lens element, f3 is the focal length of the third lens element, f4 is the focal length of the fourth lens element, f5 is the focal length of the fifth lens element, and f6 is the focal length of the sixth lens element.

Preferably, the lens satisfies the following conditional expressions:

-1.9＜f1＜-1.7， -13.5＜f2＜-11， 2＜f3＜4，

0.5＜f4＜1.5， -1.5＜f5＜-0.5， 1＜f6＜2。

preferably, the lens satisfies the following conditional expression:

1.7＜nd1＜1.9， 1.6＜nd2＜1.8， 1.5＜nd3＜1.6，

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

In the invention, all the lenses are designed to be aspheric surfaces, which is more favorable for correcting secondary spectrum and high-grade aberration, and meanwhile, the second lens and the fifth lens are made of materials with higher refractive index, which can better optimize optical structure and is favorable for lens structure design, thereby reducing lens cost.

The equation for the object-side and image-side curves of an aspheric lens is expressed 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 ^con Coefficient (the mthQ) ^con coefficient)；

Q _m ^con : mth order Q ^con Polynomial (the mthQ) ^con polynomial)。

Preferably, the lens satisfies the following conditional expressions:

45＜vd1＜60， 18＜vd2＜25， 50＜vd3＜60，

50＜vd4＜70， 18＜vd5＜25， 50＜vd6＜60，

Preferably, the lens satisfies the following conditional expressions:

5.5＜R11＜8，1.05＜R12， -2＜R21＜-1，-3＜R22＜-1.5，

-7＜R31＜-6，-2＜R32＜-1， 1＜R41＜2，-1.5＜R42＜-0.5，

-1.2＜R51＜-0.5，1.5＜R52＜3， 3＜R61＜4，-1＜R62＜-0.5，

Preferably, the ratio of the thickness of the edge of the lens to the thickness of the center of the lens of the first lens, the second lens and the fifth lens is in the range of 1.0-1.8; the ratio of the thickness of the edge of the lens to the thickness of the center of the lens of the third lens, the fourth lens and the sixth lens is in the range of 0.5-0.9. The set condition ensures that the total thickness ratio of the lens is moderate, the stability is good, and good optical performance can be still maintained under the vibration environment.

Preferably, the lens satisfies the following conditional expression: ALT/AAG > 3.5, where ALT is the sum of the central thicknesses of the first through sixth lenses and AAG is the sum of the air gaps between the first through sixth lenses.

The fisheye lens of the invention will be described in detail below with specific embodiments.

Example one

Referring to fig. 1, the present embodiment discloses a fisheye lens, which includes, in order along an optical axis from an object side a1 to an image side a2, a first lens element 1, a second lens element 2, a third lens element 3, a stop 7, a fourth lens element 4, a fifth lens element 5, and a sixth lens element 6, wherein the first lens element 1 to the sixth lens element 6 each include an object-side surface facing the object side a1 and allowing an imaging light to pass therethrough and an image-side surface facing the image side a2 and allowing the imaging light to pass therethrough;

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 and convex respectively;

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 concave and convex respectively;

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 negative refractive index, and the object-side surface and the image-side surface of the fifth lens element 5 are concave;

the sixth lens element 6 has a positive refractive index, and the sixth lens element 6 has a convex object-side surface and a convex image-side surface;

the fisheye lens has only the six lenses with the refractive index, and the TTL is less than 5mm, wherein the TTL is the distance between the object side surface of the first lens 1 and the imaging surface on the optical axis. The first lens 1 to the third lens 3 are front groups of lenses, the fourth lens 4 to the sixth lens 5 are rear groups of lenses, the first lens 1 is a glass aspheric lens, and the second lens 2 to the sixth lens 6 are all plastic aspheric lenses.

Detailed optical data of this specific example are shown in table 1.

Table 1 detailed optical data of example one

Surface of	Type (B)	Caliber size (diameter)	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									0			Infinity	Infinity
1		4.949	6.400	0.350
									2	First lens	3.044	6.550	0.450	D-LAF050	1.7713	49.29	-1.7969
3		1.533	1.110	0.656
									4	Second lens	1.292	-1.567	0.851	EP8000	1.6671	20.38	-12.4152
5		1.125	-2.352	0.055
									6	Third lens	1.045	-6.690	0.403	K26R	1.5373	55.71	2.8617
7		0.896	-1.277	0.069
									8		0.746	Infinity	-0.019
9	Fourth lens	0.814	1.143	0.576	APL5015AL	1.5463	56.00	1.0438
									10		0.948	-0.935	0.067
11	Fifth lens element	0.903	-0.812	0.330	EP5000	1.6402	23.97	-0.8659
									12		1.098	2.027	0.074
13	Sixth lens element	1.255	3.411	0.620	K26R	1.5373	55.71	1.4585
									14		1.524	-0.953	0.501
15	Cover glass	2.015	Infinity	0.210	H-K9L	1.5183	64.21	Infinity
									16		2.117	Infinity	0.160
17		2.242	Infinity	0.000

For detailed data of the aspheric surfaces of the first lens 1 to the sixth lens 6, please refer to the following table:

number of noodles

K

A4

A6

A8

A10

A12

A14

A16

2

0.00

7.485E-03

1.308E-03

-7.845E-05

-3.300E-05

0.000E+00

3

0.00

1.320E-01

-3.274E-02

2.593E-01

4.775E-02

0.000E+00

4

3.10

1.192E-01

-4.898E-01

-5.243E-02

8.058E-01

1.090E+00

7.704E+00

-1.188E+01

5

9.69

-3.277E-01

3.242E-01

2.978E+00

-5.645E-01

1.862E+01

-1.351E+02

1.868E+02

6

47.60

-4.973E-01

1.485E+00

5.797E+00

-5.838E+00

-5.215E+01

1.609E+02

-3.197E+02

7

-5.87

-7.019E-03

1.598E+00

3.242E+00

-9.753E+01

3.272E+02

1.661E+02

-2.112E+03

9

0.04

-2.117E-02

7.373E+00

-8.887E+01

6.279E+02

-3.124E+03

8.834E+03

-1.331E+04

10

-1.03

5.682E-01

2.624E-01

-2.326E+01

-4.141E+01

-5.309E+02

5.389E+03

-9.897E+03

11

-4.34

4.479E-01

-3.226E+00

2.661E+00

-8.356E+01

-1.502E+03

1.052E+04

-1.513E+04

12

10.41

7.444E-01

-2.311E+00

-1.070E+00

-2.104E+00

2.283E+01

5.838E+01

-2.251E+02

13

-97.94

6.343E-01

1.584E-01

-1.934E+00

-1.600E+00

-1.472E-01

4.127E+01

-6.948E+01

14

0.37

4.666E-01

1.004E+00

-4.217E+00

1.653E+01

-1.655E+01

-1.674E+01

2.601E+01

Fig. 1 is a schematic diagram of an optical path of an optical imaging lens in this embodiment. Please refer to fig. 2, which shows that when the spatial frequency of the lens reaches 100lp/mm, the full-field transfer function image is still larger than 0.5, the center-to-edge uniformity is high, the imaging quality is excellent, and the resolution of the lens is high. Referring to fig. 3, the defocus graph of the lens under 435nm-656nm visible light shows that the defocus amount of the lens under visible light is small. Please refer to fig. 4, which shows that the later color is smaller than ± 4um in the 435nm-656nm wide visible spectrum band, which ensures that the blue edge or red edge of the projection image does not occur, and has high image color reducibility. Please refer to fig. 5, which shows that the axial chromatic aberration is less than ± 0.02mm, the color reduction is good, the chromatic aberration is small, and the blue-violet edge phenomenon is not obvious. Please refer to fig. 6 for the field curvature and distortion diagram of the lens under the visible light of 435nm-656nm, and it can be seen from the diagram that the optical distortion is controlled within 2%, the wide-angle distortion is strictly controlled, the image quality is improved, the distortion is not required to be corrected by the later image algorithm, and the application is convenient. Please refer to fig. 7, which shows that the central focus shift amount is less than 6um, and the defocus amount of the lens under near infrared light is small.

Example two

As shown in fig. 8 to 14, the surface convexoconcave 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

Surface of	Type (B)	Caliber size (diameter)	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									0			Infinity	Infinity
1		4.939	6.400	0.3500
									2	First lens	3.032	6.547	0.4498	D-LAF050	1.77	49.2902	-1.8000
3		1.529	1.111	0.6465
									4	Second lens	1.329	-1.567	0.8501	EP8000	1.67	20.3815	-12.3875
5		1.180	-2.353	0.0543
									6	Third lens	1.104	-6.654	0.4023	APL5014CL_14	1.55	55.9870	2.8380
7		1.007	-1.284	0.0706
									8		0.744	Infinity	-0.015
9	Fourth lens	0.817	1.140	0.576	APL5015AL	1.55	56.00	1.042
									10		0.950	-0.934	0.067
11	Fifth lens element	0.903	-0.812	0.329	EP5000	1.64	23.97	-0.866
									12		1.097	2.027	0.073
13	Sixth lens element	1.256	3.403	0.620	K26R	1.54	55.71	1.458
									14		1.532	-0.953	0.5013
15	Cover glass	2.030	Infinity	0.2100	H-K9L	1.52	64.2124	Infinity
									16		2.135	Infinity	0.1493
17		2.253	Infinity	0.0000

For detailed data of parameters of the aspheric surfaces of the first lens 1 to the sixth lens 6, refer to the following table:

number of noodles

K

A4

A6

A8

A10

A12

A14

A16

2

0.00

7.478E-03

1.306E-03

-7.936E-05

-3.417E-05

0.000E+00

3

0.00

1.348E-01

-3.143E-02

2.602E-01

4.878E-02

0.000E+00

4

3.10

1.190E-01

-4.899E-01

-5.222E-02

8.068E-01

1.092E+00

7.710E+00

-1.185E+01

5

9.69

-3.273E-01

3.245E-01

2.978E+00

-5.631E-01

1.863E+01

-1.351E+02

1.870E+02

6

48.32

-4.978E-01

1.484E+00

5.794E+00

-5.845E+00

-5.217E+01

1.608E+02

-3.200E+02

7

-5.90

-6.085E-03

1.602E+00

3.260E+00

-9.747E+01

3.275E+02

1.670E+02

-2.108E+03

9

0.08

-1.457E-02

7.381E+00

-8.889E+01

6.274E+02

-3.124E+03

8.832E+03

-1.332E+04

10

-1.02

5.669E-01

2.593E-01

-2.326E+01

-4.139E+01

-5.308E+02

5.389E+03

-9.894E+03

11

-4.36

4.494E-01

-3.222E+00

2.668E+00

-8.359E+01

-1.503E+03

1.052E+04

-1.515E+04

12

10.41

7.443E-01

-2.311E+00

-1.068E+00

-2.087E+00

2.296E+01

5.876E+01

-2.237E+02

13

-97.67

6.343E-01

1.583E-01

-1.934E+00

-1.605E+00

-1.692E-01

4.119E+01

-6.973E+01

14

0.37

4.664E-01

1.004E+00

-4.217E+00

1.654E+01

-1.654E+01

-1.673E+01

2.603E+01

Fig. 8 is a schematic diagram of an optical path of an optical imaging lens in this embodiment. Please refer to fig. 9, which shows that when the spatial frequency of the lens reaches 100lp/mm, the full-field transfer function image is still larger than 0.4, the center-to-edge uniformity is high, the imaging quality is excellent, and the resolution of the lens is high. Referring to fig. 10, the defocus graph of the lens under 435nm-656nm visible light shows that the defocus amount of the lens under visible light is small. Referring to fig. 11, it can be seen that, in the 435nm-656nm wide visible spectrum band, the filter color is smaller than ± 4um, so as to ensure that no blue edge or red edge of the projected image occurs, and have high image color reducibility. Referring to fig. 12, it can be seen that the longitudinal chromatic aberration curve of the lens under the visible light 435nm-656nm is less than ± 0.02mm, the color restoration is good, the chromatic aberration is small, and the blue-violet edge phenomenon is not obvious. Please refer to fig. 13 for the field curvature and distortion diagram of the lens under the visible light 435nm-656nm, and it can be seen from the diagram that the optical distortion is controlled within 2%, the wide-angle distortion is strictly controlled, the image quality is improved, the distortion is not required to be corrected by the later image algorithm, and the application is convenient. Referring to fig. 14, it can be seen that the central focal shift amount of the lens under near infrared light 850nm is less than 6um, and the defocus amount of the lens under near infrared light is small.

EXAMPLE III

As shown in fig. 15 to 21, the surface convexoconcave 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 III

Surface of	Type (B)	Caliber size (diameter)	Radius of curvature	Thickness of	Material quality	Refractive index	Coefficient of dispersion	Focal length
									0			Infinity	Infinity
1		4.935	6.4000	0.3500
									2	First lens	3.031	6.5611	0.4490	D-LAF050	1.7713	49.2902	-1.793
3		1.529	1.1083	0.6538
									4	Second lens	1.287	-1.5667	0.8506	EP9000	1.6776	19.2758	-12.362
5		1.126	-2.3498	0.0540
									6	Third lens	1.046	-6.722	0.403	K26R	1.54	55.71	2.858
7		0.898	-1.276	0.069
									8		0.747	Infinity	-0.019
9	Fourth lens	0.813	1.143	0.577	APL5015AL	1.55	56.00	1.044
									10		0.947	-0.936	0.067
11	Fifth lens element	0.903	-0.8106	0.3290	EP5000	1.6402	23.9718	-0.865
									12		1.096	2.0269	0.0732
13	Sixth lens element	1.244	3.4162	0.6201	K26R	1.5373	55.7107	1.459
									14		1.504	-0.9526	0.5013
15	Cover glass	2.015	Infinity	0.2100	H-K9L	1.5183	64.2124	Infinity
									16		2.119	Infinity	0.1596
17		2.251	Infinity	0.0000

number of noodles

K

A4

A6

A8

A10

A12

A14

A16

2

0.00

7.455E-03

1.298E-03

-8.104E-05

-3.346E-05

0.000E+00

3

0.00

1.322E-01

-3.130E-02

2.623E-01

4.994E-02

0.000E+00

4

3.11

1.190E-01

-4.892E-01

-5.207E-02

8.017E-01

1.097E+00

7.721E+00

-1.183E+01

5

9.60

-3.246E-01

3.282E-01

2.970E+00

-5.847E-01

1.858E+01

-1.352E+02

1.862E+02

6

46.86

-4.981E-01

1.494E+00

5.819E+00

-5.838E+00

-5.228E+01

1.606E+02

-3.209E+02

7

-5.74

-6.458E-03

1.587E+00

3.312E+00

-9.737E+01

3.257E+02

1.575E+02

-2.072E+03

9

0.01

-2.737E-02

7.365E+00

-8.885E+01

6.280E+02

-3.123E+03

8.839E+03

-1.331E+04

10

-1.03

5.686E-01

2.820E-01

-2.320E+01

-4.138E+01

-5.309E+02

5.390E+03

-9.901E+03

11

-4.35

4.489E-01

-3.217E+00

2.840E+00

-8.262E+01

-1.501E+03

1.051E+04

-1.515E+04

12

10.39

7.445E-01

-2.309E+00

-1.060E+00

-2.122E+00

2.277E+01

5.883E+01

-2.243E+02

13

-97.64

6.344E-01

1.581E-01

-1.936E+00

-1.607E+00

-1.576E-01

4.133E+01

-6.929E+01

14

0.37

4.669E-01

1.005E+00

-4.215E+00

1.653E+01

-1.654E+01

-1.673E+01

2.600E+01

Fig. 15 is a schematic diagram of an optical path of an optical imaging lens in this embodiment. Please refer to fig. 16, which shows that when the spatial frequency of the lens reaches 100lp/mm, the full-field transfer function image is still larger than 0.5, the center-to-edge uniformity is high, the imaging quality is excellent, and the resolution of the lens is high. Referring to fig. 17, the defocus graph of the lens under the visible light of 435nm-656nm shows that the defocus amount of the lens under the visible light is small. Referring to fig. 18, it can be seen that, in the 435nm-656nm wide visible spectrum band, the later color is smaller than ± 4um, so as to ensure that no blue edge or red edge of the projected image occurs, and have high image color reducibility. Please refer to fig. 19 for a longitudinal chromatic aberration curve of the lens under 435nm-656nm of visible light, and it can be seen from the graph that the axial chromatic aberration is less than ± 0.02mm, the color restoration is good, the chromatic aberration is small, and the blue-violet phenomenon is not obvious. Please refer to fig. 20 for the field curvature and distortion diagram of the lens under the visible light of 435nm-656nm, it can be seen from the diagram that the optical distortion is controlled within 2%, the wide-angle distortion is strictly controlled, the image quality is improved, the distortion is not required to be corrected by the later image algorithm, and the application is convenient. Referring to fig. 21, it can be seen that the central field defocus amount of the lens under near infrared light 850nm is less than 6um, and the defocus amount of the lens under near infrared light is small.

Example four

As shown in fig. 22 to 28, 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 4.

Table 4 detailed optical data for example four

Surface of	Type (B)	Caliber size (diameter)	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									0			Infinity	Infinity
1		4.8933	6.4000	0.350
									2	First lens	2.9763	6.3972	0.448	D-LAF050	1.7713	49.29	-1.700
3		1.4817	1.0549	0.639
									4	Second lens	1.276	-1.567	0.851	EP8000	1.67	20.38	-12.676
5		1.114	-2.341	0.050
									6	Third lens	1.039	-7.000	0.402	K26R	1.54	55.71	2.832
7		0.903	-1.275	0.068
									8		0.749	Infinity	-0.018
9	Fourth lens	0.8153	1.1262	0.582	APL5015AL	1.5463	56.00	1.042
									10		0.9505	-0.9403	0.070
11	Fifth lens element	0.9072	-0.8097	0.324	EP5000	1.6402	23.97	-0.865
									12		1.0795	2.0247	0.068
13	Sixth lens element	1.2251	3.5221	0.622	K26R	1.5373	55.71	1.469
									14		1.4339	-0.9546	0.501
15	Cover glass	1.9961	Infinity	0.210	H-K9L	1.5183	64.21	Infinity
									16		2.1116	Infinity	0.154
17		2.2602	Infinity	0.000

number of noodles

K

A4

A6

A8

A10

A12

A14

A16

2

0.00

7.051E-03

1.195E-03

-8.809E-05

-1.770E-05

0.000E+00

3

0.00

1.309E-01

-7.609E-03

3.058E-01

1.411E-01

0.000E+00

4

3.12

1.168E-01

-4.901E-01

-5.745E-02

7.757E-01

1.015E+00

7.766E+00

-1.108E+01

5

9.34

-3.193E-01

3.524E-01

2.961E+00

-5.933E-01

1.857E+01

-1.353E+02

1.811E+02

6

50.21

-4.906E-01

1.446E+00

5.766E+00

-5.638E+00

-5.264E+01

1.567E+02

-3.506E+02

7

-4.84

-3.235E-02

1.563E+00

3.303E+00

-9.760E+01

3.187E+02

1.261E+02

-1.833E+03

9

-0.17

-3.846E-02

7.096E+00

-8.877E+01

6.310E+02

-3.104E+03

8.864E+03

-1.386E+04

10

-1.03

5.675E-01

3.325E-01

-2.291E+01

-4.034E+01

-5.269E+02

5.414E+03

-1.005E+04

11

-4.34

4.469E-01

-3.215E+00

3.439E+00

-7.904E+01

-1.495E+03

1.054E+04

-1.527E+04

12

10.28

7.415E-01

-2.303E+00

-1.064E+00

-2.199E+00

2.287E+01

6.503E+01

-2.088E+02

13

-90.89

6.348E-01

1.520E-01

-1.944E+00

-1.549E+00

2.557E-01

4.285E+01

-6.607E+01

14

0.36

4.695E-01

1.013E+00

-4.189E+00

1.659E+01

-1.645E+01

-1.664E+01

2.606E+01

Fig. 22 is a schematic diagram of an optical path of an optical imaging lens in this embodiment. Please refer to fig. 23, which shows that when the spatial frequency of the lens reaches 100lp/mm, the full-field transfer function image is still larger than 0.45, the center-to-edge uniformity is high, the imaging quality is excellent, and the resolution of the lens is high. Please refer to fig. 24, which shows the defocus curve of the lens in 435nm-656nm of visible light, and it can be seen that the defocus amount of the lens in visible light is small. Referring to fig. 25, it can be seen that, in the 435nm-656nm wide visible spectrum band, the later color is smaller than ± 4um, so as to ensure that no blue edge or red edge of the projected image occurs, and have high image color reducibility. Please refer to fig. 26, which shows that the axial chromatic aberration is less than ± 0.02mm, the color reduction is good, the chromatic aberration is small, and the blue-violet phenomenon is not obvious. Please refer to fig. 27 for the field curvature and distortion diagram of the lens under the visible light of 435nm-656nm, and it can be seen from the diagram that the optical distortion is controlled within 2%, the wide-angle distortion is strictly controlled, the image quality is improved, the distortion is not required to be corrected by the later image algorithm, and the application is convenient. Please refer to fig. 28, which shows that the central focus shift amount is less than 6um, and the defocus amount of the lens under near infrared light is small.

EXAMPLE five

As shown in fig. 29 to 35, the surface convexoconcave 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 is shown in table 5.

Table 5 detailed optical data for example five

Surface of	Type (B)	Caliber size (diameter)	Radius of curvature	Thickness of	Material quality	Refractive index	Coefficient of dispersion	Focal length
									0			Infinity	Infinity
1		4.869	6.400	0.350
									2	First lens	2.953	6.248	0.448	D-LAF050	1.77	49.29	-1.700
3		1.472	1.050	0.626
									4	Second lens	1.296	-1.577	0.860	EP8000	1.67	20.38	-13.068
5		1.091	-2.345	0.053
									6	Third lens	1.042	-7.000	0.466	K26R	1.54	55.71	2.758
7		0.968	-1.251	0.073
									8		0.766	Infinity	-0.022
9	Fourth lens	0.811	1.104	0.607	K26R	1.54	55.71	1.069
									10		0.941	-0.966	0.090
11	Fifth lens element	0.893	-0.772	0.320	EP6000	1.64	23.53	-0.831
									12		1.105	2.036	0.050
13	Sixth lens element	1.240	3.643	0.577	APL5015AL	1.55	56.00	1.447
									14		1.393	-0.953	0.501
15	Cover glass	2.003	Infinity	0.210	H-K9L	1.52	64.21	Infinity
									16		2.134	Infinity	0.144
17		2.280	Infinity	0.000

number of noodles

K

A4

A6

A8

A10

A12

A14

A16

2

0.00

6.536E-03

8.588E-04

-1.504E-04

2.677E-05

0.000E+00

3

0.00

1.323E-01

3.980E-02

2.997E-01

9.761E-02

0.000E+00

4

3.06

1.148E-01

-4.113E-01

2.848E-02

6.339E-01

6.388E-01

7.896E+00

-1.144E+01

5

6.61

-2.549E-01

6.453E-01

2.722E+00

-1.692E+00

1.817E+01

-1.326E+02

1.770E+02

6

72.99

-5.201E-01

1.421E+00

5.687E+00

-7.408E+00

-6.222E+01

1.357E+02

-2.866E+02

7

-1.07

-2.226E-01

1.017E+00

6.172E+00

-9.094E+01

2.607E+02

-1.888E+02

-1.662E+02

9

-1.76

-1.993E-01

7.560E+00

-8.737E+01

6.121E+02

-3.091E+03

9.675E+03

-1.635E+04

10

-1.73

6.300E-01

3.529E-01

-2.155E+01

-3.586E+01

-5.645E+02

5.316E+03

-9.800E+03

11

-4.46

4.748E-01

-3.236E+00

5.451E+00

-5.463E+01

-1.502E+03

1.002E+04

-1.579E+04

12

9.69

7.242E-01

-2.154E+00

-5.600E-01

-3.431E+00

1.762E+01

7.496E+01

-2.236E+02

13

-32.38

6.788E-01

1.996E-01

-1.943E+00

-1.490E+00

4.660E-01

4.283E+01

-7.020E+01

14

0.31

5.283E-01

1.077E+00

-4.057E+00

1.680E+01

-1.618E+01

-1.654E+01

2.277E+01

Fig. 29 is a schematic diagram of an optical path of an optical imaging lens in this embodiment. Please refer to fig. 30 for the MTF curve under 435nm-656nm of the lens, it can be seen that when the spatial frequency of the lens reaches 100lp/mm, the full-field transfer function image is still larger than 0.45, the center-to-edge uniformity is high, the imaging quality is excellent, and the resolution of the lens is high. Please refer to fig. 31, which shows the defocus curve of the lens under 435nm-656nm, and it can be seen that the defocus amount of the lens under visible light is small. Please refer to fig. 32, which shows that the filter color is smaller than ± 4um in the 435-656 nm wide visible spectrum band, so as to ensure that the blue edge or red edge of the projection image does not occur, and have high image color reducibility. Please refer to fig. 33 for a longitudinal chromatic aberration curve diagram of the lens under the visible light of 435nm-656nm, and it can be seen from the graph that the axial chromatic aberration is less than ± 0.02mm, the color restoration is good, the chromatic aberration of the color is small, and the blue-violet edge phenomenon is not obvious. Please refer to fig. 34 for the field curvature and distortion diagram of the lens under the visible light 435nm-656nm, it can be seen from the diagram that the optical distortion is controlled within 2%, the wide-angle distortion is strictly controlled, the image quality is improved, the distortion is not required to be corrected by the later image algorithm, and the application is convenient. Please refer to fig. 35, which shows that the central focus shift amount is less than 6um, and the defocus amount of the lens under near infrared light is small.

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. The fisheye lens is characterized by sequentially comprising a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens from an object side to an image side along an optical axis, wherein the first lens to the sixth 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;

2. The fish-eye lens as claimed in claim 1, wherein the first to third lenses are front lenses, the fourth to sixth lenses are rear lenses, the first lens is a glass aspheric lens, and the second to sixth lenses are all plastic aspheric lenses, and satisfy 2 < f456/f < 3, where f456 is a focal length of the rear lenses and f is an overall focal length of the lenses.

3. A fisheye lens as claimed in claim 1, characterized in that the following condition is satisfied:

2＜|f1/f|＜3，15.5＜|f2/f|＜17，3＜|f3/f|＜5，

1＜|f4/f|＜3，1＜|f5/f|＜2，1.5＜|f6/f|＜3，

4. A fisheye lens as claimed in claim 3, characterized in that the following condition is satisfied:

-1.9＜f1＜-1.7，-13.5＜f2＜-11，2＜f3＜4，

0.5＜f4＜1.5，-1.5＜f5＜-0.5，1＜f6＜2。

5. a fish-eye lens as claimed in claim 1, wherein the following conditional expression is satisfied:

1.7＜nd1＜1.9，1.6＜nd2＜1.8，1.5＜nd3＜1.6，

1.5＜nd4＜1.7，1.6＜nd5＜1.7，1.5＜nd6＜1.7，

6. A fish-eye lens as claimed in claim 1, wherein the following conditional expression is satisfied:

45＜vd1＜60，18＜vd2＜25，50＜vd3＜60，

50＜vd4＜70，18＜vd5＜25，50＜vd6＜60，

7. A fish-eye lens as claimed in claim 1, wherein the following conditional expression is satisfied:

5.5＜R11＜8，1.05＜R12，-2＜R21＜-1，-3＜R22＜-1.5，

-7＜R31＜-6，-2＜R32＜-1，1＜R41＜2，-1.5＜R42＜-0.5，

-1.2＜R51＜-0.5，1.5＜R52＜3，3＜R61＜4，-1＜R62＜-0.5，

8. The fish-eye lens of claim 1, wherein the ratio of the thickness of the edge of the lens to the thickness of the center of the lens of the first lens, the second lens and the fifth lens is in the range of 1.0-1.8; the ratio of the thickness of the edge of the lens to the thickness of the center of the lens of the third lens, the fourth lens and the sixth lens is in the range of 0.5-0.9.

9. A fish-eye lens as claimed in claim 1, wherein the following conditional expression is satisfied: and ImgH/AAG is more than 3.5, wherein ImgH is the image height on the imaging surface of the system, and AAG is the sum of the air gaps between the first lens and the sixth lens.

10. A fish-eye lens as claimed in claim 1, wherein the following conditional expression is satisfied: ALT/AAG > 3.5, where ALT is the sum of the central thicknesses of the first through sixth lenses and AAG is the sum of the air gaps between the first through sixth lenses.