CN209496195U

CN209496195U - A kind of fish eye lens

Info

Publication number: CN209496195U
Application number: CN201920427480.8U
Authority: CN
Inventors: 曹来书; 李雪慧
Original assignee: Xiamen Li Ding Au Optronics Co
Current assignee: Xiamen Li Ding Au Optronics Co; Xiamen Leading Optics Co Ltd
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2019-10-15
Anticipated expiration: 2029-03-29

Abstract

The utility model relates to lens technology field, a kind of particularly fish eye lens.The utility model discloses a kind of fish eye lenses, along an optical axis successively include the first lens, the second lens, the third lens, diaphragm, the 4th lens, the 5th lens and the 6th lens from object side to image side；First lens are the meniscus for having negative refractive index；Second lens are the meniscus for having negative refractive index；The third lens have positive refractive index, and object side is convex surface；4th lens are the concave-convex lens for having positive refractive index, and are non-spherical lens；5th lens are the convex-convex lens for having positive refractive index；6th lens are the concave-convex lens for having negative refractive index.The utility model has system length, the big image planes for shortening camera lens, and the advantages of the enough optical properties of maintenance and image quality.

Description

A kind of fish eye lens

Technical field

The utility model belongs to lens technology field, more particularly to a kind of fish eye lens.

Background technique

Fish eye lens is that a kind of focal length is 16mm or shorter and ultra-wide angle camera lens.The front lens diameter of this camera lens is very big And protruded in parabolical to camera lens front, it is rather similar to the eyes of fish, so being commonly called as " fish eye lens ".Fish eye lens has been at present It is widely used in the fields such as safety monitoring, vehicle-mounted, it is therefore, also higher and higher for fish-eye requirement, not only require Preferable quality of optical imaging also requires to reduce camera lens volume, but existing common fish eye lens uses more eyeglass, not only It is at high cost, and system length is longer, generally higher than 15mm is unable to satisfy small form factor requirements；In addition, existing common fish eye lens Image planes are small, are less than 5mm, sensor utilization is low, is unable to satisfy the growing requirement of consumer.

Summary of the invention

The purpose of this utility model is to provide a kind of number of lenses, and system length, image planes less, that shorten camera lens are big, and Maintain the fish eye lens of enough optical properties and image quality above-mentioned to solve the problems, such as.

To achieve the above object, the technical solution adopted in the utility model are as follows: a kind of fish eye lens, from object side to image side edge One optical axis successively includes the first lens, the second lens, the third lens, diaphragm, the 4th lens, the 5th lens and the 6th lens；It should First lens to the 6th lens respectively include one towards object side and the object side for passing through imaging ray and one towards image side and Make the image side surface that imaging ray passes through；

First lens have negative refractive index, and the object side of first lens is convex surface, and the image side surface of first lens is recessed Face；

Second lens have negative refractive index, and the object side of second lens is convex surface, and the image side surface of second lens is recessed Face；

The third lens have positive refractive index, and the object side of the third lens is convex surface；

4th lens have positive refractive index, and the object side of the 4th lens is concave surface, and the image side surface of the 4th lens is convex Face, the object side of the 4th lens and image side surface are aspherical；

5th lens have positive refractive index, and the object side of the 5th lens is convex surface, and the image side surface of the 5th lens is convex Face；

6th lens have negative refractive index, and the object side of the 6th lens is concave surface, and the image side surface of the 6th lens is convex Face；

There are the fish eye lens lens of refractive index there was only above-mentioned six.

Further, the image side surface of the third lens is plane.

Further, the diaphragm is set up directly on the image side surface of the third lens.

Further, which also meets: D12/R12≤1.845, wherein D12 is the light admission port of first lens Diameter, R12 are the radius of curvature of the first lens image side surface.

Further, which also meets: D22/R22≤1.83, wherein D22 is the light admission port of second lens Diameter, R22 are the radius of curvature of the second lens image side surface.

Further, the object side of the image side surface and the 6th lens of the 5th lens is mutually glued.

Further, which also meets: 2 < | R56 | < 3, wherein R56 is the 5th lens and the 6th lens Cemented surface radius of curvature.

Further, the 4th lens are made of glass material.

Further, which also meets: 1.45 < nd1 < 1.6,68 < vd1 < 72,1.45 < nd2 < 1.6,68 < vd2 < 72,1.7 < nd3 < 1.9,45 < vd3 < 52,1.55 < nd4 < 1.75,50 < vd4 < 58,1.68 < nd5 < 1.78,50 < vd5 < 55,1.9 < Nd6 < 2.0,15 < vd6 < 20, wherein nd1-nd6 respectively indicates the refractive index of first lens to the 6th lens in d line, vd1- Vd6 respectively indicate first lens to the 6th lens d line abbe number.

Further, which also meets: 2.4 < ALT/ALG < 2.8, wherein ALG be first lens to this The air gap summation of six lens on the optical axis, ALT are first lens to the 6th lens six on the optical axis thoroughly The summation of mirror thickness.

The advantageous effects of the utility model:

The utility model uses six-element lens, and by the refractive index and concave-convex curved surface arrangement design to each lens, Less with number of lenses, at low cost, the system length of camera lens is short (being less than 12.5mm), and image planes are big (being greater than 5.6mm), and maintain The advantages of enough optical properties and image quality；In addition, the utility model also has the outer diameter of the first lens smaller, infrared defocus Lesser advantage.

Detailed description of the invention

It, below will be to required in embodiment description in order to illustrate more clearly of the technical scheme in the embodiment of the utility model Attached drawing to be used is briefly introduced, it should be apparent that, the accompanying drawings in the following description is only some implementations of the utility model Example, for those of ordinary skill in the art, without creative efforts, can also be according to these attached drawings Obtain other attached drawings.

Fig. 1 is the structural schematic diagram of the utility model embodiment one；

The MTF figure that Fig. 2 is the visible light 0.435-0.656um of the utility model embodiment one；

The MTF figure that Fig. 3 is the infrared 850nm of the utility model embodiment one；

Fig. 4 is the defocusing curve figure of the visible light 0.435-0.656um of the utility model embodiment one；

Fig. 5 is the defocusing curve figure of the infrared ray 850nm of the utility model embodiment one；

Fig. 6 is the curvature of field and distortion schematic diagram of the utility model embodiment one；

The MTF figure that Fig. 7 is the visible light 0.435-0.656um of the utility model embodiment two；

The MTF figure that Fig. 8 is the infrared 850nm of the utility model embodiment two；

Fig. 9 is the defocusing curve figure of the visible light 0.435-0.656um of the utility model embodiment two；

Figure 10 is the defocusing curve figure of the infrared ray 850nm of the utility model embodiment two；

Figure 11 is the curvature of field and distortion schematic diagram of the utility model embodiment two；

The MTF figure that Figure 12 is the visible light 0.435-0.656um of the utility model embodiment three；

The MTF figure that Figure 13 is the infrared 850nm of the utility model embodiment three；

Figure 14 is the defocusing curve figure of the visible light 0.435-0.656um of the utility model embodiment three；

Figure 15 is the defocusing curve figure of the infrared ray 850nm of the utility model embodiment three；

Figure 16 is the curvature of field and distortion schematic diagram of the utility model embodiment three；

The MTF figure that Figure 17 is the visible light 0.435-0.656um of the utility model embodiment four；

The MTF figure that Figure 18 is the infrared 850nm of the utility model embodiment four；

Figure 19 is the defocusing curve figure of the visible light 0.435-0.656um of the utility model embodiment four；

Figure 20 is the defocusing curve figure of the infrared ray 850nm of the utility model embodiment four；

Figure 21 is the curvature of field and distortion schematic diagram of the utility model embodiment four；

The MTF figure that Figure 22 is the visible light 0.435-0.656um of the utility model embodiment five；

The MTF figure that Figure 23 is the infrared 850nm of the utility model embodiment five；

Figure 24 is the defocusing curve figure of the visible light 0.435-0.656um of the utility model embodiment five；

Figure 25 is the defocusing curve figure of the infrared ray 850nm of the utility model embodiment five；

Figure 26 is the curvature of field and distortion schematic diagram of the utility model embodiment five；

Figure 27 is the numerical tabular of each important parameter of five embodiments of the utility model.

Specific embodiment

To further illustrate each embodiment, the utility model is provided with attached drawing.These attached drawings are in the utility model discloses A part of appearance mainly to illustrate embodiment, and can cooperate the associated description of specification former come the running for explaining embodiment Reason.Cooperation refers to these contents, and those of ordinary skill in the art will be understood that other possible embodiments and sheet are practical new The advantages of type.Component in figure is not necessarily to scale, and similar component symbol is conventionally used to indicate similar component.

Now in conjunction with the drawings and specific embodiments, the present invention will be further described.

Described " lens have positive refractive index (or negative refractive index) ", refers to the lens with first-order theory theoretical calculation Paraxial refractive index out is positive (or being negative).Described " the object sides (or image side surface) of lens " are defined as imaging ray and pass through The particular range of lens surface.The face shape bumps judgement of lens can pass through according to the judgment mode of skill usual in the field The sign of radius of curvature (being abbreviated as R value) judges the bumps of lens face shape deflection.R value common can be used in optical design software In, such as Zemax or CodeV.R value is also common in the lens data sheet (lens data sheet) of optical design software.With For object side, when R value be timing, be determined as object side be convex surface；When R value is negative, determine that object side is concave surface.Conversely, For image side surface, when R value is timing, judgement image side surface is concave surface；When R value is negative, determine that image side surface is convex surface.

The utility model provides a kind of fish eye lens, along an optical axis successively includes the first lens, from object side to image side Two lens, the third lens, diaphragm, the 4th lens, the 5th lens and the 6th lens；First lens to the 6th lens respectively include One towards object side and the object side for passing through imaging ray and one towards image side and the image side surface that passes through imaging ray；

4th lens have positive refractive index, and the object side of the 4th lens is concave surface, and the image side surface of the 4th lens is convex Face, the object side of the 4th lens and image side surface be it is aspherical, be conducive to correct spherical aberration, the aberrations such as coma, improve MTF parsing Degree.

There are the fish eye lens lens of refractive index there was only above-mentioned six, using six-element lens, and by each lens Refractive index and concave-convex curved surface arrangement design, have number of lenses it is less, at low cost, the system length of camera lens is short, and image planes are big, And the advantages of maintaining enough optical properties and image quality.

Preferably, the image side surface of the third lens is plane, and three pieces lens are in lesser inclination before can facilitating guarantee diaphragm Tolerance assembling promotes assembling yield, and certainly, in some embodiments, the image side surface of the third lens is also possible to convex surface or recessed Face.

It is furthermore preferred that the diaphragm is set up directly on the image side surface of the third lens, in conjunction with the aspherical of the 4th lens Rise control+- 5um can manage lesser tolerance of interval convenient for diaphragm interval, and three pieces lens are smaller before can facilitating guarantee diaphragm Tilt tolerance assembling, improve product yield.

Preferably, which also meets: D12/R12≤1.845, wherein D12 is the light admission port of first lens Diameter, R12 are the radius of curvature of the first lens image side surface, are realized under the premise of low f-theta distorts function, convenient for technique plus Work.

Preferably, which also meets: D22/R22≤1.83, wherein and D22 is the clear aperture of second lens, R22 is the radius of curvature of the second lens image side surface, realizes under the premise of low f-theta distorts function, processes convenient for technique.

Preferably, the object side of the image side surface and the 6th lens of the 5th lens is mutually glued, further eliminates color difference.

It is furthermore preferred that the fish eye lens also meets: 2 < | R56 | < 3, wherein R56 is the 5th lens and the 6th lens The radius of curvature of cemented surface, the R56 value is bigger, and the inclined face sensitivity of the axis of the lens is lower, but also can accordingly reduce MTF simultaneously, because This, under the premise of meeting certain MTF, R56 value need to take OK range.

Preferably, the 4th lens are made of glass material, improve temperature drift rejection ability.

Preferably, which also meets: 1.45 < nd1 < 1.6,68 < vd1 < 72,1.45 < nd2 < 1.6,68 < vd2 < 72,1.7 < nd3 < 1.9,45 < vd3 < 52,1.55 < nd4 < 1.75,50 < vd4 < 58,1.68 < nd5 < 1.78,50 < vd5 < 55,1.9 < Nd6 < 2.0,15 < vd6 < 20, wherein nd1-nd6 respectively indicates the refractive index of first lens to the 6th lens in d line, vd1- Vd6 respectively indicate first lens to the 6th lens d line abbe number.Series material combination may be implemented preferable It can be seen that with infrared confocal property, the infrared offset IR shift < 10um of 850nm, and the first lens are identical as the second lens material, It is all using the material compared with low-refraction, price is very low.

Preferably, which also meets: 2.4 < ALT/ALG < 2.8, wherein ALG is first lens to the 6th The air gap summation of the lens on the optical axis, ALT are six lens of first lens to the 6th lens on the optical axis The summation of thickness, further to shorten fish-eye system length, and easy to manufacture, optimization of system config.

Preferably, the first lens, the second lens, the third lens, the 5th lens and the 6th lens are made of glass material, But not limited to this, in some embodiments, it is also possible to be made of the other materials such as plastic cement.

It will be described in detail below with optical imaging lens of the specific embodiment to the utility model.

Implement one

It along an optical axis I successively include the first lens 1, from object side A1 to image side A2 as shown in Figure 1, a kind of fish eye lens Two lens 2, the third lens 3, diaphragm (not shown), the 4th lens 4, the 5th lens 5, the 6th lens 6,7 and of plate glass Imaging surface 8；First lens, 1 to the 6th lens 6 respectively include one towards object side A1 and the object side that passes through imaging ray with And one towards image side A2 and the image side surface that passes through imaging ray；

First lens 1 have negative refractive index, and the object side 11 of first lens 1 is convex surface, the image side surface of first lens 1 12 be concave surface；

Second lens 2 have negative refractive index, and the object side 21 of second lens 2 is convex surface, the image side surface of second lens 2 22 be concave surface；

The third lens 3 have positive refractive index, and the object side 31 of the third lens 3 is convex surface, the image side surface of the third lens 3 32 be plane, and the diaphragm is set up directly in the plane 32；

4th lens 4 have positive refractive index, and the object side 41 of the 4th lens 4 is concave surface, the image side surface of the 4th lens 4 42 be convex surface, and the object side 41 of the 4th lens 4 and image side surface 42 are aspherical；

5th lens 5 have positive refractive index, and the object side 51 of the 5th lens 5 is convex surface, the image side surface of the 5th lens 5 52 be convex surface；

6th lens 6 have negative refractive index, and the object side 61 of the 6th lens 6 is concave surface, the image side surface of the 6th lens 6 62 be convex surface.

In this specific embodiment, the 5th lens 5 and the 6th lens 6 are balsaming lens.

The detailed optical data of this specific embodiment are as shown in table 1-1.

The detailed optical data of table 1-1 embodiment one

Surface		Radius of curvature	Thickness	Material	Refractive index	Abbe number	Focal length
								-	Object plane shot	Plane	Infinity
11	First lens	13.48	0.50	Glass	1.49	70.42	-6.22
								12		2.45	1.11
21	Second lens	4.85	0.5	Glass	1.49	70.42	-4.54
								22		1.47	0.78
31	The third lens	6.35	1.20	Glass	1.74	49.24	8.50
								32		Plane	0.00
-	Diaphragm	Plane	0.63
								41	4th lens	-24.54(ASG)	1.63	Glass	1.69	53.20	3.43
42		-2.23(ASG)	0.08
								51	5th lens	11.20	1.79	Glass	1.73	54.67	3.22
52		-2.79	0
								61	6th lens	-2.79	0.90	Glass	1.95	17.94	-4.32
62		-9.88	1.13
								7	Plate glass	Plane	0.7	Glass	1.52	64.21	-
-		Plane	1.24
								8	Imaging surface	Plane

In this specific embodiment, the object side 41 of the 4th lens 4 and image side surface 42 are defined according to following aspheric curve formula:

Wherein:

Z: (point for being y apart from optical axis on aspherical and is tangential on cutting for vertex on aspherical optical axis for aspherical depth Face, vertical range between the two)；

C: the curvature (the vertex curvature) of aspheric vertex of surface；

K: conical surface coefficient (Conic Constant)；

Radial distance (radial distance)

r_n: normalization radius (normalization radius (NRADIUS))；

U:r/r_n；

a_m: m rank Q^conCoefficient (is the m^th Q^concoefficient)；

Q_m ^con: m rank Qcon multinomial (the m^th Q^conpolynomial)；

Each aspherical parameter detailed data please refers to following table:

Surface	41	42
			K=	-1.10E+01	4.42E-01
a₄=	-1.67E-02	1.05E-02
			a₆=	1.15E-02	-3.82E-03
a₈=	-1.77E-02	4.63E-03
			a₁₀=	1.18E-02	-1.76E-03
a₁₂=	-3.46E-03	3.24E-04

The numerical value of each conditional expression of this specific embodiment please refers to Figure 27, wherein T1 is first lens 1 at this Thickness on optical axis I, T2 are thickness of second lens 2 on optical axis I, and T3 is thickness of the third lens 3 on optical axis I Degree, T4 are thickness of the 4th lens 4 on optical axis I, and T5 is thickness of the 5th lens 5 on optical axis I, T6 be this Thickness of six lens 6 on optical axis I, G12 are first lens 1 to the air gap of the second lens 2 on optical axis I, G23 For second lens 2 to the air gap of the third lens 3 on optical axis I；G45 is that the 4th lens 4 to the 5th lens 5 exist The air gap on optical axis I, Gstop are the air gap summation before and after the diaphragm, and TTL is that first lens 1 exist to the imaging surface 8 Distance on optical axis I.

The resolving power of this specific embodiment please refers to Fig. 2 and 3, can be seen from the chart that resolving power is good, high resolution, it is seen that Figure 4 and 5 are please referred to the confocal property of infrared 850nm, it can be seen that visible light and infrared confocal property are good, the infrared offset IR of 850nm Shift < 10um, the curvature of field and distortion figure are detailed in (A) of Fig. 6 and (B) of Fig. 6.

In this specific embodiment, fish-eye focal length f=1.95mm；F-number FNO=2.3；Image planes size Ф= 5.61mm；TTL=12.1963mm, FOV=180 ° of field angle.

Implement two

The present embodiment is identical as the face type bumps and refractive index of each lens of embodiment one, only the curvature of each lens surface The optical parameters such as radius, lens thickness are different.

The detailed optical data of this specific embodiment are as shown in table 2-1.

The detailed optical data of table 2-1 embodiment two

Surface		Radius of curvature	Thickness	Material	Refractive index	Abbe number	Focal length
								-	Object plane shot	Plane	Infinity
11	First lens	13.17	0.49	Glass	1.49	70.42	-6.22
								12		2.44	1.07
21	Second lens	4.88	0.50	Glass	1.49	70.42	-4.53
								22		1.47	0.79
31	The third lens	6.33	1.24	Glass	1.74	49.24	8.48
								32		Plane	0
-	Diaphragm	Plane	0.62
								41	4th lens	-25.02(ASG)	1.62	Glass	1.69	53.20	3.42
42		-2.24(ASG)	0.08
								51	5th lens	11.30	1.80	Glass	1.73	54.67	3.23
52		-2.79	0
								61	6th lens	-2.79	0.92	Glass	1.95	17.94	-4.32
62		-9.99	1.13
								7	Plate glass	Plane	0.7	Glass	1.52	64.21	-
-		Plane	1.24
								8	Imaging surface	Plane

Each aspherical parameter detailed data of this specific embodiment please refers to following table:

Surface	41	42
			K=	-6.24E+00	4.42E-01
a₄=	-1.66E-02	1.05E-02
			a₆=	1.13E-02	-3.83E-03
a₈=	-1.77E-02	4.63E-03
			a₁₀=	1.19E-02	-1.76E-03
a₁₂=	-3.43E-03	3.24E-04

The numerical value of each conditional expression of this specific embodiment please refers to Figure 27.

The resolving power of this specific embodiment please refers to Fig. 7 and 8, can be seen from the chart that resolving power is good, high resolution, it is seen that Fig. 9 and 10 are please referred to the confocal property of infrared 850nm, it can be seen that visible light and infrared confocal property are good, the infrared offset IR of 850nm Shift < 10um, the curvature of field and distortion figure are detailed in (A) of Figure 11 and (B) of Figure 11.

In this specific embodiment, fish-eye focal length f=1.97mm；F-number FNO=2.3；Image planes size Ф= 5.68mm；TTL=12.1979mm, FOV=180 ° of field angle.

Implement three

The detailed optical data of this specific embodiment are as shown in table 3-1.

The detailed optical data of table 3-1 embodiment three

Surface		Radius of curvature	Thickness	Material	Refractive index	Abbe number	Focal length
								-	Object plane shot	Plane	Infinity
11	First lens	12.90	0.48	Glass	1.49	70.42	-6.23
								12		2.43	1.05
21	Second lens	4.89	0.53	Glass	1.49	70.42	-4.55
								22		1.47	0.79
31	The third lens	6.33	1.26	Glass	1.74	49.24	8.48
								32		Plane	0
-	Diaphragm	Plane	0.61
								41	4th lens	-24.93(ASG)	1.62	Glass	1.69	53.20	3.43
42		-2.24(ASG)	0.08
								51	5th lens	11.32	1.80	Glass	1.73	54.67	3.24
52		-2.80	0
								61	6th lens	-2.80	0.93	Glass	1.95	17.94	-4.32
62		-10.05	1.13
								7	Plate glass	Plane	0.7	Glass	1.52	64.21	-
-		Plane	1.24
								8	Imaging surface	Plane

Surface	41	42
			K=	-9.36E+00	4.42E-01
a₄=	-1.65-02	1.05E-02
			a₆=	1.13-02	-3.82E-03
a₈=	-1.77E-02	4.63E-03
			a₁₀=	1.19-02	-1.76E-03
a₁₂=	-3.46E-03	3.23-04

The resolving power of this specific embodiment please refers to Figure 12 and 13, can be seen from the chart that resolving power is good, high resolution can See and please refer to Figure 14 and 15 with the confocal property of infrared 850nm, it can be seen that visible light and infrared confocal property are good, the infrared offset of 850nm IR shift < 10um is measured, the curvature of field and distortion figure are detailed in (A) of Figure 16 and (B) of Figure 16.

In this specific embodiment, fish-eye focal length f=1.98mm；F-number FNO=2.3；Image planes size Ф= 5.73mm；TTL=12.1996mm, FOV=180 ° of field angle.

Implement four

The detailed optical data of this specific embodiment are as shown in table 4-1.

The detailed optical data of table 4-1 example IV

Surface		Radius of curvature	Thickness	Material	Refractive index	Abbe number	Focal length
								-	Object plane shot	Plane	Infinity
11	First lens	12.70	0.47	Glass	1.49	70.42	-6.23
								12		2.43	1.02
21	Second lens	4.86	0.52	Glass	1.49	70.42	-4.56
								22		1.47	0.79
31	The third lens	6.34	1.28	Glass	1.74	49.24	8.49
								32		Plane	0.00
-	Diaphragm	Plane	0.59
								41	4th lens	-24.93(ASG)	1.62	Glass	1.69	53.20	3.43
42		-2.24ASG)	0.08
								51	5th lens	11.36	1.80	Glass	1.73	54.67	3.25
52		-2.81	0
								61	6th lens	-2.81	0.94	Glass	1.95	17.94	-4.33
62		-10.10	1.13
								7	Plate glass	Plane	0.7	Glass	1.52	64.21	-
-		Plane	1.24
								8	Imaging surface	Plane

The resolving power of this specific embodiment please refers to Figure 17 and 18, can be seen from the chart that resolving power is good, high resolution can See and please refer to Figure 19 and 20 with the confocal property of infrared 850nm, it can be seen that visible light and infrared confocal property are good, the infrared offset of 850nm IR shift < 10um is measured, the curvature of field and distortion figure are detailed in (A) of Figure 21 and (B) of Figure 21.

In this specific embodiment, fish-eye focal length f=1.99mm；F-number FNO=2.3；Image planes size Ф= 5.78mm；TTL=12.1874mm, FOV=180 ° of field angle.

Implement five

The detailed optical data of this specific embodiment are as shown in Table 5-1.

The detailed optical data of table 5-1 embodiment five

Surface	41	42
			K=	-2.99E+01	4.38E-01
a₄=	-1.64E-02	1.06E-02
			a₆=	1.15E-02	-3.78E-03
a₈=	-1.75E-02	4.64E-03
			a₁₀=	1.20E-02	-1.76E-03
a₁₂=	-3.58E-03	3.25E-04

The resolving power of this specific embodiment please refers to Figure 22 and 23, can be seen from the chart that resolving power is good, high resolution can See and please refer to Figure 24 and 25 with the confocal property of infrared 850nm, it can be seen that visible light and infrared confocal property are good, the infrared offset of 850nm IR shift < 10um is measured, the curvature of field and distortion figure are detailed in (A) of Figure 26 and (B) of Figure 26.

In this specific embodiment, fish-eye focal length f=2.00mm；F-number FNO=2.3；Image planes size Ф= 5.83mm；TTL=12.1971mm, FOV=180 ° of field angle.

The utility model has number of lenses less, at low cost, and the system length of camera lens is short (being less than 12.5mm), and image planes are big (being greater than 5.6mm), and the advantages of the enough optical properties of maintenance and image quality；In addition, the utility model also has the first lens Outer diameter it is smaller, the infrared lesser advantage of defocus.

Although specifically showing and describing the utility model in conjunction with preferred embodiment, those skilled in the art is answered This is understood, in the spirit and scope for not departing from the utility model defined by the appended claims, in form and details On the utility model can be made a variety of changes, be the protection scope of the utility model.

Claims

1. a kind of fish eye lens, it is characterised in that: from object side to image side along an optical axis successively include the first lens, the second lens, The third lens, diaphragm, the 4th lens, the 5th lens and the 6th lens；First lens to the 6th lens respectively include a direction Object side and the object side for passing through imaging ray and one are towards image side and the image side surface that passes through imaging ray；

First lens have negative refractive index, and the object side of first lens is convex surface, and the image side surface of first lens is concave surface；

Second lens have negative refractive index, and the object side of second lens is convex surface, and the image side surface of second lens is concave surface；

4th lens have positive refractive index, and the object side of the 4th lens is concave surface, and the image side surface of the 4th lens is convex surface, should The object side of 4th lens and image side surface are aspherical；

5th lens have positive refractive index, and the object side of the 5th lens is convex surface, and the image side surface of the 5th lens is convex surface；

6th lens have negative refractive index, and the object side of the 6th lens is concave surface, and the image side surface of the 6th lens is convex surface；

2. fish eye lens according to claim 1, it is characterised in that: the image side surface of the third lens is plane.

3. fish eye lens according to claim 2, it is characterised in that: the diaphragm is set up directly on the picture of the third lens On side.

4. fish eye lens according to claim 1, which is characterized in that the fish eye lens also meets: D12/R12≤1.845, Wherein, D12 is the clear aperture of first lens, and R12 is the radius of curvature of the first lens image side surface.

5. fish eye lens according to claim 1, which is characterized in that the fish eye lens also meets: D22/R22≤1.83, Wherein, D22 is the clear aperture of second lens, and R22 is the radius of curvature of the second lens image side surface.

6. fish eye lens according to claim 1, it is characterised in that: the image side surface of the 5th lens and the object of the 6th lens Side is mutually glued.

7. fish eye lens according to claim 6, which is characterized in that the fish eye lens also meets: 2 < | R56 | < 3, wherein R56 is the radius of curvature of the cemented surface of the 5th lens and the 6th lens.

8. fish eye lens according to claim 1, it is characterised in that: the 4th lens are made of glass material.

9. fish eye lens according to claim 1, which is characterized in that the fish eye lens also meets: 1.45 < nd1 < 1.6,68 < vd1 < 72,1.45 < nd2 < 1.6,68 < vd2 < 72,1.7 < nd3 < 1.9,45 < vd3 < 52,1.55 < nd4 < 1.75,50 < vd4 < 58, 1.68 < nd5 < 1.78,50 < vd5 < 55,1.9 < nd6 < 2.0,15 < vd6 < 20, wherein nd1-nd6 respectively indicates first lens To the 6th lens d line refractive index, vd1-vd6 respectively indicate first lens to the 6th lens d line abbe number.

10. fish eye lens according to claim 1, it is characterised in that: the fish eye lens also meets: 2.4 < ALT/ALG < 2.8, wherein ALG is the air gap summation of first lens to the 6th lens on the optical axis, and ALT is first lens To the summation of six lens thickness of the 6th lens on the optical axis.