CN104297904A - Large-aperture ultra wide angle lens - Google Patents

Abstract

The invention provides a large-aperture ultra wide angle lens. The large-aperture ultra wide angle lens comprises a front set, a lens screen and a rear set. Particularly, a first negative lens, a second negative lens, a third positive lens, a fourth positive lens, a fifth negative lens and the sixth positive lens are included in the light incident direction; the front set is composed of the first negative lens, the second negative lens and the third positive lens; the rear set is composed of the fourth positive lens, the fifth negative lens and the sixth positive lens. The number F of the large-aperture ultra wide angle lens reaches 1.6, the large-aperture ultra wide angle lens has the large aperture, more light can be controlled to enter the lens, and the use requirement under the dark environment can be met. Meanwhile, the lens has the ultra wide angle, and meets the imaging requirement with the maximum field angle of 150 degrees. In addition, the six lenses are simple in assembling structure according to the reasonable arrangement among elements, and the large-aperture ultra wide angle lens is simple in structure, excellent in performance, good in tolerance, easy to manufacture and cheap.

Description

A kind of large aperture bugeye lens

Technical field

The present invention relates to optical lens design field, particularly relate to a kind of large aperture bugeye lens.

Background technology

As everyone knows, the diameter of the focal length/lens aperture of lens aperture F value=camera lens, therefore for the camera lens of the same focal length, the F value of aperture is less, characterize camera lens relative diaphragm diameter larger, the aperture of at present conventional visible ray large aperture imaging system is F2.0, and what have can accomplish F1.8, but time in the environment that some is darker, need to control more light and enter camera lens.

In addition, the size of field angle determines the field range of optical instrument, and field angle is larger, and the visual field is larger, and optical power is less, just can be taken in in visual field by object of finding a view more expediently.Along with the progress of technology, the application of consumption electronic product to wide-angle lens of imaging class gets more and more, and meets the special applications of large aperture and ultra-wide angle especially simultaneously.

Therefore, need a kind of large aperture bugeye lens, to avoid above-mentioned defect.

Summary of the invention

The object of the present invention is to provide a kind of large aperture bugeye lens, the special applications of large aperture and ultra-wide angle can be met simultaneously.

For solving the problem, the invention provides a kind of large aperture bugeye lens, comprise front group, diaphragm and rear group, concrete is comprised successively by light direction: the first negative lens, the second negative lens, the 3rd positive lens, the 4th positive lens, the first negative lens and the 6th positive lens, group before described first negative lens, the second negative lens and the 3rd positive lens are formed, group after described 4th positive lens, the 5th negative lens and the 6th positive lens are formed.

Further, described first negative lens has the convex first surface to object space and the recessed second surface to image space, is positioned at the top of camera lens;

Described second negative lens has recessed the 3rd surface to object space;

Described 3rd positive lens has convex surperficial and convex in image space the 6th surface to the 5th of object space;

Described 4th positive lens has convex the 7th surface to object space and convex the 8th surface to image space;

Described 5th negative lens has recessed the 9th surface to object space and recessed the tenth surface to image space;

Described 6th positive lens has recessed the 11 surface to object space and recessed the 12 surface to image space.

Further, described diaphragm is between the 6th surface and the 7th surface of described 4th positive lens of described 3rd positive lens.

Further, be provided with aperture diaphragm between the 6th surface of described 3rd positive lens and the 7th surface of the 4th lens, this aperture diaphragm is fixed aperture.

Further, except the 5th negative lens, all eyeglasses of camera lens all adopt the eyeglass of plastic material, compare glass material, plastic material has that quality is light, cost is low, be easy to the advantages such as machine-shaping, and the production cost of wide-angle lens is significantly reduced, and is suitable for producing in enormous quantities.

Further, the focal length rounding arrangement of mirrors sheet is f, and second eyeglass focal length is f2, and the 3rd eyeglass focal length is f3, and above parameter meets following relation:

1<f2/f<3.5；

1.5<f3/f<3.5 and

0.3<f2/f3<1.5。

Further, the radius-of-curvature of getting described first positive lens thing side is R1, and image side radius-of-curvature is R2, and the thing side radius-of-curvature of the second negative lens is R3 and image side radius-of-curvature is R4, and above parameter meets following relation:

1.5<R2<2.5,0<R2/ (R1+R2) <0.1 and

-1.5<(R3+R4)/(R3-R4)<0。

Further, the thickness getting the first positive lens is T1, and the second negative lens thickness T2, meets following formula between T1 and T2:

0.1<T1/(T1+T2)<1。

Further, the surface of each lens of described large aperture bugeye lens is aspheric surface, its surperficial radian of aspherical lens is different from common spheric glass, the curved surface of eyeglass is just needed to change in order to pursue eyeglass thinness, and adopted spherical design in the past, aberration and distortion are increased, the bad phenomenon such as result occurs that obvious image is unclear, and visual field is distorted, the visual field is narrow and small; Aspheric design, have modified image, solves the problems such as visual field distortion, meanwhile, make eyeglass gentlier, thinner, more flat; And, still keep excellent shock resistance, wearer is used safely.

Further, described each lens non-spherical surface is even aspheric surface, and asphere coefficient meets following equation:

$z=\frac{{\mathrm{CY}}^2}{1+\sqrt{1-(1+k)C^2{Y}^2}}+\underset{i=2}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i{Y}^{2i}$

Wherein, i=2,3,4 ... N, z are the coordinates along optical axis direction, and Y is the radial coordinate in units of length of lens unit, and C is curvature (1/R), k is circular cone coefficient (Coin Constant), α _ibe the coefficient of each high-order term, 2i is aspheric high power (the order of Aspherical Coefficient).

Further, described each lens non-spherical surface can also be odd aspheric surface, and asphere coefficient meets following equation:

$z=\frac{{\mathrm{CY}}^2}{1+\sqrt{1-(1+k)C^2{Y}^2}}+\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_i{Y}^i$

Wherein, i=1,2,3,4 ... N, equally also can reach purpose of design, z is the coordinate along optical axis direction, and Y is the radial coordinate in units of length of lens unit, and C is curvature (1/R), k is circular cone coefficient (Coin Constant), β _ibe the coefficient of each high-order term, i is aspheric high power (the order of Aspherical Coefficient).

Further, the refractive index n of described first negative lens and dispersion v scope are respectively: 1.5 < n ₁< 1.6,50 < v ₁< 60;

Refractive index n and the dispersion v scope of described second negative lens are respectively: 1.5 < n ₂< 1.6,50 < v ₂< 60;

Refractive index n and the dispersion v scope of described 3rd positive lens are respectively: 1.5 < n ₂< 1.6,50 < v ₂< 60;

Refractive index n and the dispersion v scope of described 4th positive lens are respectively: 1.5 < n ₂< 1.6,50 < v ₂< 60;

Refractive index n and the dispersion v scope of described 5th negative lens are respectively: 1.6 < n ₄< 1.7,23 < v ₄< 25;

Refractive index n and the dispersion v scope of described 6th positive lens are respectively: 1.5 < n ₂< 1.6,50 < v ₂< 60.

Further, the image side on the 12 surface of described 6th lens also has optical filter, enters camera lens for filtering Infrared.

Preferably, described filter material is the glass material of BK7 model, and its thickness is 0.3mm, and refractive index and dispersion are respectively n=1.5168, v=64.17, utilizes IR cut film plating process to eliminate Infrared and enters.

Compared with prior art, the invention provides a kind of large aperture bugeye lens, the first surface of the first negative lens is comparatively smooth, 4th surface of the second negative lens is comparatively smooth, first negative lens and the second negative lens are used for carrying out high angle scattered light collection, effective bending axis outer visual field chief ray, makes it diminish relative to the angle of optical axis, and then reduces the size of rear set of pieces; 3rd positive lens is drum type lens, and it acts on is make the divergent rays of front group generation through pooling thus passing through aperture diaphragm below.What organize lens set employing after system aperture diaphragm is general optical collection system, wherein group the 4th positive lens and negative lens have larger focal power afterwards, effect is positive and negative lens combination color difference eliminating, the incident angle that 6th positive lens makes the outer chief ray of axle specify according to CMOS chip carries out deviation, preferably while guarantee illuminance uniformity is matched to image-position sensor.Camera lens provided by the invention adopts six eyeglasses, and its F number is 1.6, has larger aperture, can control more light and enter in camera lens, meets compared with the user demand under dark situation, has ultra-wide angle simultaneously, meet the imaging requirements of maximum 150 degree of field angle.In addition, except the 5th negative lens is except glass mirror, all the other eyeglasses are glass lens, and the quality of glass lens is light, cost is low, be easy to machine-shaping, and the production cost of wide-angle lens is significantly reduced, and are suitable for producing in enormous quantities.Each eyeglass is according to the Rational Arrangement between each element, and package assembly is simple, function admirable, and tolerance is good, manufactures simple, cheap.

Accompanying drawing explanation

Fig. 1 is the structural representation of the embodiment of the present invention one;

Fig. 2 is the MTF curve map of the embodiment of the present invention one under limiting resolution;

Fig. 3 is the MTF curve map of the embodiment of the present invention one under 1/2 limiting resolution;

Fig. 4 is the optical field diagram of the embodiment of the present invention one;

Fig. 5 is the optical distortion figure of the embodiment of the present invention one;

Fig. 6 is the point range figure of the embodiment of the present invention one;

Fig. 7 is the chromatic curve figure of the embodiment of the present invention one;

Fig. 8 is the relative luminance curve figure of the embodiment of the present invention one.

Reference numeral: L1, the first negative lens, L2, the second negative lens, L3, the 3rd positive lens; L4 the 4th positive lens; L5, the 5th negative lens, L6, the 6th positive lens, S1, first surface; S2, second surface; S3, the 3rd surface, S4, the 4th surface, S5, the 5th surface; S6, the 6th surface; S7, the 7th surface, S8, the 8th surface, S9, the 9th surface; S10, the tenth surface; S11, the 11 surface, S12, the 12 surface, A, diaphragm; F, cutoff filter, P, cover glass.

Embodiment

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Embodiment one

As shown in Figure 1, the present embodiment provides a kind of large aperture bugeye lens, comprise front group, diaphragm A and rear group, concrete is comprised successively by light direction: the first negative lens L1, the second negative lens L2, the 3rd positive lens L3, the 4th positive lens L4, the 5th negative lens L5 and the 6th positive lens L6, group before described first negative lens L1, the second negative lens L2 and the 3rd positive lens L3 are formed, group after described 4th positive lens L4, the 5th negative lens L5 and the 6th positive lens L6 are formed.

Described first negative lens L1 has the convex first surface S1 to object space and the recessed second surface S2 to image space, is positioned at the top of camera lens;

Described second negative lens L2 has recessed the 3rd surperficial S3 to object space;

Described 3rd positive lens L3 has convex the 5th surperficial S5 to object space and convex in the surperficial S6 of image space the 6th;

Described 4th positive lens L4 has convex the 7th surperficial S7 to object space and convex the 8th surperficial S8 to image space;

Described 5th negative lens L5 has recessed the 9th surperficial S9 to object space and recessed the tenth surperficial S10 to image space;

Described 6th positive lens L6 has recessed the 11 surperficial S11 to object space and recessed the 12 surperficial S12 to image space.

Be provided with aperture diaphragm A between the 6th surperficial S6 of described 3rd positive lens L3 and the 7th surperficial S7 of the 4th lens, this aperture diaphragm A is fixed aperture A.

The first surface S1 of described first negative lens L1 and the 4th surperficial S4 of described second negative lens L2 is almost plane, described first negative lens L1 and the second negative lens L2, be used for carrying out high angle scattered light collection, effective bending axis outer visual field chief ray, make it diminish relative to the angle of optical axis, and then reduce the size of rear set of pieces.Thereafter the 3rd positive lens L3 is drum type lens, and it acts on and is the divergent rays that before converging, group produces thus the aperture diaphragm A passed through below; What organize lens set employing after system aperture diaphragm A is general optical collection system, wherein organize the structure that the 4th positive lens L4 and the 5th negative lens L5 forms similar gummed afterwards, there is larger focal power, effect is positive and negative lens combination color difference eliminating, the incident angle that 6th positive lens L6 makes the outer chief ray of axle specify according to CMOS chip carries out deviation, preferably while guarantee illuminance uniformity is matched to image-position sensor.

5th negative lens L5 adopts glass mirror, all the other lens all adopt the eyeglass of plastic material, compare glass material, and plastic material has that quality is light, cost is low, be easy to the advantages such as machine-shaping, the production cost of wide-angle lens is significantly reduced, is suitable for producing in enormous quantities.

The focal length rounding arrangement of mirrors sheet is f, and the second negative lens L2 focal length is f2, and the 3rd positive lens L3 focal length is f3, meets following relation between above parameter:

1<f2/f<3.5；

1.5<f3/f<3.5 and

0.3<f2/f3<1.5。

The radius-of-curvature of getting described first negative lens L1 thing side is R1 and image side radius-of-curvature is R2, and the thing side radius-of-curvature of the second negative lens L2 is R3 and image side radius-of-curvature is meet following relation between R4, R1 and R2, between R3 and R4:

1.5<R2<2.5,0<R2/ (R1+R2) <0.1 and

-1.5<(R3+R4)/(R3-R4)<0。

The thickness getting the first negative lens L1 is T1, and the second negative lens L2 thickness is meet following formula between T2, T1 and T2:

0.1<T1/(T1+T2)<1。

The surface of each lens of described large aperture bugeye lens is aspheric surface, its surperficial radian of aspherical lens is different from common spheric glass, the curved surface of eyeglass is just needed to change in order to pursue eyeglass thinness, and adopted spherical design in the past, the aberration made and distortion increase, the bad phenomenon such as result occurs that obvious image is unclear, and visual field is distorted, the visual field is narrow and small; Aspheric design, have modified image, solves the problems such as visual field distortion, meanwhile, make eyeglass gentlier, thinner, more flat; And, still keep excellent shock resistance, wearer is used safely.

Table 1 is the system structure parameter of a kind of wide-angle lens in one embodiment of the invention.As shown in table 1, show respectively:

The optical surface (Surface) of sequentially numbering along light direction, comprise successively: the first surface S1 of the first negative lens L1, the second surface S2 of the first negative lens L1, the 3rd surperficial S3 of the second negative lens L2, the 4th surperficial S4 of the second negative lens L2, the 5th surperficial S5 of the 3rd positive lens L3, the 6th surperficial S6 of the 3rd positive lens L3, the 7th surperficial S7 of the 4th positive lens L4, the 8th surperficial S8 of the 4th positive lens L4, the 9th surperficial S9 of the 5th negative lens L5, the tenth surperficial S10 of the 5th negative lens L5, the 11 surperficial S11 of the 6th positive lens L6, the 12 surperficial S12 of the 6th positive lens L6, cutoff filter F, cover glass P, wherein: surface type (Type), the curvature (C) of each optical surface on optical axis, along the thickness (T) on the optical axis in light direction between each optical surface and adjacent next optical surface, along the material (Glass) on the optical axis in light direction between each optical surface and adjacent next optical surface, half bore (Semi-Diameter), circular cone coefficient (Conic), focal power (Focal power), wherein, the unit of thickness (T) and half bore (Semi-Diameter) is mm, the unit of curvature (C) and focal power (Focal power) is mm ^-1.

Table 2 is aspherical surface datas of large aperture wide-angle lens in an embodiment, on the basis of table 1, and the even asphericity coefficient α of each optical surface ₂, α ₃, α ₄, α ₅, α ₆, α ₇, α ₈as shown in table 2, wherein asphericity coefficient can meet following equation:

$z=\frac{{\mathrm{CY}}^2}{1+\sqrt{1-(1+k)C^2{Y}^2}}+\underset{i=2}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i{Y}^{2i}$

In the present embodiment, i=7 and quadratic term are up to 14 powers, and z is the coordinate along optical axis direction, and Y is the radial coordinate in units of length of lens unit, and C is curvature (1/R), k is circular cone coefficient (Coin Constant), α _ibe the coefficient of each high-order term, 2i is aspheric high power (the order of Aspherical Coefficient), adopts aspheric design, have modified image, solves the problems such as visual field distortion, meanwhile, make eyeglass gentlier, thinner, more flat.And, still keep excellent shock resistance, wearer is used safely.

Table 1

surface

Type

Curvature

Thickness

Glass

Semi-Diameter

Conic

S1

EVENASPH

0.0359

1.0046

E48R

6.2193

-4.5637

S2	EVENASPH	0.4367	4.0470	?	3.3156	-0.6187
							S3	EVENASPH	-0.2231	1.0322	E48R	3.2478	0.3589
S4	EVENASPH	0.0124	1.6153	?	3.3482	0.0000
							S5	EVENASPH	0.2372	3.9944	E48R	3.4710	-1.0782
S6	EVENASPH	-0.1583	2.4907	?	3.1116	0.6276
							A	STANDARD	0.0000	-0.2282	?	1.5908	0.0000
S7	EVENASPH	0.2661	1.2280	E48R	1.6789	-0.1460
							S8	EVENASPH	-0.1929	0.2129	?	1.7161	-0.6211
S9	EVENASPH	-0.1942	0.5000	SP3810	1.6847	-0.1732
							S10	EVENASPH	0.2664	0.0800	?	1.7491	0.2613
S11	EVENASPH	0.2473	1.5168	E48R	1.8209	-1.9851
							S12	EVENASPH	-0.1154	0.4000	?	1.7764	-19.5312
14	STANDARD	0.0000	0.3000	BK7	1.8614	0.0000
							15	STANDARD	0.0000	1.7930	?	1.9148	0.0000
16	STANDARD	0.0000	0.4000	BK7	2.4114	0.0000
							17	STANDARD	0.0000	0.0500	?	2.4832	0.0000
18	STANDARD	0.0000	0.0000	?	2.4794	0.0000

Table 2

surface

α 2

α 3

α 4

α 5

α 6

α 7

S1

-4.54E-04

-2.07E-06

2.00E-07

-9.66E-11

-4.80E-11

3.90E-13

S2

-1.00E-03

8.78E-06

-3.12E-05

2.38E-06

-3.21E-07

7.59E-09

S3

4.33E-04

1.21E-04

-5.62E-06

-3.74E-07

1.59E-07

-4.94E-09

S4

-5.98E-04

6.15E-05

8.46E-07

-2.58E-07

-5.89E-08

3.97E-09

S5

-7.97E-04

6.61E-05

-1.74E-06

-1.19E-07

-5.04E-09

-4.86E-10

S6

3.51E-03

-1.86E-05

-9.95E-07

-1.72E-07

-8.09E-09

1.05E-09

A

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

S7

3.50E-04

1.02E-04

-2.88E-04

4.78E-05

3.27E-05

-1.67E-05

S8

2.02E-03

2.35E-04

-5.45E-05

-9.57E-05

-3.51E-05

5.85E-06

S9

2.97E-04

6.64E-04

-3.92E-04

-7.77E-05

1.65E-05

4.24E-06

S10

-2.29E-03

-1.48E-03

1.40E-05

-8.66E-06

-2.39E-05

5.06E-06

S11

9.05E-03

2.32E-03

-2.85E-04

-6.74E-05

1.10E-05

-1.52E-06

S12

1.36E-02

1.78E-03

6.50E-04

1.30E-04

1.56E-05

-1.30E-05

14

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

15

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

16

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

17

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

18

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

0.00E+00

As shown in Table 1: described first negative lens L1 adopts the eyeglass of E4R model plastic material, and its refractive index n and dispersion v is respectively n ₁=1.53, v ₁=56;

Second negative lens L2 adopts the eyeglass of E4R model plastic material, and its refractive index n and dispersion v is respectively n ₂=1.53, v ₂=56;

3rd positive lens L3 adopts the eyeglass of E4R model plastic material, and its refractive index n and dispersion v is respectively n ₃=1.53, v ₃=56;

4th positive lens L4 adopts the eyeglass of E4R model plastic material, and its refractive index n and dispersion v is respectively n ₄=1.53, v ₄=56;

5th negative lens L5 adopts the eyeglass of SP3810 model plastic material, and its refractive index n and dispersion v is respectively n ₅=1.64, v ₆=23.3;

6th positive lens L6 adopts the eyeglass of E4R model plastic material, and its refractive index n and dispersion v is respectively n ₆=1.53, v ₆=56.

The image side of described 6th positive lens L6 is provided with cutoff filter F and cover glass P along light direction; the material of described cutoff filter F and cover glass P is BK7 glass; the thickness 0.3mm of cutoff filter F; refractive index and dispersion are respectively n=1.5168, v=64.17.IR cut film plating process is utilized to eliminate Infrared.

Corresponding, adopt odd aspherical equation to design, the general formula of odd aspherical equation is as follows:

$z=\frac{{\mathrm{CY}}^2}{1+\sqrt{1-(1+k)C^2{Y}^2}}+\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_i{Y}^i$

Wherein, i=1,2,3,4 ... N, z is the coordinate along optical axis direction, and Y is the radial coordinate in units of length of lens unit, and C is curvature (1/R), k is circular cone coefficient (Coin Constant), α _ibe the coefficient of each high-order term, i is aspheric high power (the order of Aspherical Coefficient), equally also can reach purpose of design.

Be provided with diaphragm A between described 3rd positive lens L3 and the 4th positive lens L4, described diaphragm A is aperture diaphragm.

The present embodiment large aperture bugeye lens coordinates OV9712 chip can realize 150 degree of field angle, and distortion is controlled within 65%, camera lens overall length is less than 20.5m, the transport function of camera lens is at Nyquist frequency 166lp/mm (line is to every millimeter), more than 0.4 is reached within 0.8 visual field, realize visible light wave range (430nm-650nm) blur-free imaging, lens focus 1.87mm, F number is 1.6, coordinate CMOS pixel dimension 3um, Diagonal Dimension 4.528mm, cutoff frequency 166lp/mm (line is to every millimeter).

Shown in Fig. 2 and Fig. 3 is the MTF curve map of the embodiment of the present invention one under limiting resolution and the MTF curve map of the embodiment of the present invention one under 1/2 limiting resolution respectively, MTF transfer curve figure (optical transfer function) can the image quality of concentrated expression system, its curve shape is more level and smooth, and X-axis height is higher relatively, the image quality of proof system is better.Fig. 2 reflection be MTF curve under sensor limiting resolution, in Fig. 2 and Fig. 3, different curve represents each field rays respectively, from figure, under limiting resolution and below 1/2 limiting resolution, curve in transfer curve figure is comparatively smoothly compact, the mtf value that Curves characterizes is very high, and the aberration of illustrative system obtains good correction.

Please refer to the optical field diagram of the embodiment of the present invention one shown in Fig. 4, in curvature of field curve, right side graph is meridian direction, leftmost curve is Sagittal field curvature, the two does the astigmatism that difference is exactly system, astigmatism and the curvature of field are the important aberrations affecting the outer field rays of axle, astigmatism crosses the image quality of the serious system that the has influence on off-axis ray of conference, the curvature of field can cause center and peripheral optimal imaging not in one plane, from figure, the curvature of field of system and astigmatism are all corrected within 50um, show that the curvature of field of the present embodiment and astigmatism are corrected in a goodr scope.

Figure 5 shows that the distortion figure of the embodiment of the present invention one, the sharpness of the not influential system of distorting, but the anamorphose of system can be caused, for wide-angle lens, correcting distorted is very difficult, and the distortion of native system is less than 65%, and this illustrates that distortion has been remedied to an extraordinary degree.

Figure 6 shows that the point range figure of the embodiment of the present invention one, the disperse degree that each field rays of point range figure display system converges at image planes place and formed, so it characterizes system obtain various difference characteristic, the image quality of the less proof system of RMS radius of point range figure is better.The disc of confusion RMS diameter of native system is all less than 15um, illustrates that aberration correction is very good.

Figure 7 shows that the chromatic curve figure of the embodiment of the present invention one, aberration is also known as chromatic aberation, and be a major defect of lens imaging, aberration is exactly the difference of color in simple terms, occurs in polychromatic light when being light source.Known according to figure, the wide-angle lens aberration that the present embodiment provides, within 6um, shows that its Difference Control is good.

Figure 8 shows that the relative luminance curve figure of the embodiment of the present invention one, relative brightness refers to the brightness ratio along optical axis field angle and full filed angle on imaging plane, the i.e. diagonal corners brightness of image sensor and the ratio of central brightness, according to picture, the present embodiment one bugeye lens is when field angle 150 degree, its relative brightness still reaches more than 50%, and show that system can have good performance under low-light (level), image quality meets the demands.

This enforcement provides a kind of large aperture bugeye lens, the first surface S1 of the first negative lens L1 is comparatively smooth, the 4th surperficial S4 of the second negative lens L2 is comparatively smooth, first negative lens L1 and the second negative lens L2 is used for carrying out high angle scattered light collection, effective bending axis outer visual field chief ray, make it diminish relative to the angle of optical axis, and then reduce the size of rear set of pieces; 3rd positive lens L3 is drum type lens, and it acts on is make the divergent rays of front group generation through pooling thus passing through aperture diaphragm A below.What organize lens set employing after system aperture diaphragm A is general optical collection system, wherein group the 4th positive lens L4 and negative lens have larger focal power afterwards, effect is positive and negative lens combination color difference eliminating, the incident angle that 6th positive lens L6 makes the outer chief ray of axle specify according to CMOS chip carries out deviation, preferably while guarantee illuminance uniformity is matched to image-position sensor.Camera lens provided by the invention adopts six eyeglasses, and its F number is 1.6, has larger aperture, can control more light and enter in camera lens, meets compared with the user demand under dark situation, has ultra-wide angle simultaneously, meet the imaging requirements of maximum 150 degree of field angle.In addition, only need a slice glass mirror, in batch production, significantly reduce production cost, six eyeglasses are according to the Rational Arrangement between each element, and package assembly is simple, function admirable, and tolerance is good, manufacture simple, cheap.

Obviously, those skilled in the art can carry out various change and modification to invention and not depart from the spirit and scope of the present invention.Like this, if these amendments of the present invention and modification belong within the scope of the claims in the present invention and equivalent technologies thereof, then the present invention is also intended to comprise these change and modification.

Claims (10)

1. a large aperture bugeye lens, comprises the first negative lens, the second negative lens, the 3rd positive lens, the 4th positive lens, the 5th negative lens and the 6th positive lens successively by light direction, it is characterized in that:

Described first negative lens has the convex first surface to object space and the recessed second surface to image space;

Described second negative lens has recessed the 3rd surface to object space;

Described 3rd positive lens has convex surperficial and convex in image space the 6th surface to the 5th of object space;

Described 4th positive lens has convex the 7th surface to object space and convex the 8th surface to image space;

Described 5th negative lens has recessed the 9th surface to object space and recessed the tenth surface to image space;

Described 6th positive lens has recessed the 11 surface to object space and recessed the 12 surface to image space.

The focal length rounding arrangement of mirrors sheet is f, and the focal length of the second negative lens is f2, and the focal length of the 3rd positive lens is f3, and above parameter meets following relation:

1<f2/f<3.5；

1.5<f3/f<3.5 and

0.3<f2/f3<1.5。

2. large aperture bugeye lens according to claim 1, it is characterized in that: the radius-of-curvature of getting described first negative lens thing side is R1, image side radius-of-curvature is R2, and the thing side radius-of-curvature of the second negative lens is R3 and image side radius-of-curvature is R4, and above parameter meets following relation:

1.5<R2<2.5,0<R2/ (R1+R2) <0.1 and

-1.5<(R3+R4)/(R3-R4)<0。

3. large aperture bugeye lens according to claim 1, is characterized in that: the thickness getting the first negative lens is T1, and the thickness T2 of the second negative lens, meets following formula between T1 and T2:

0.1<T1/(T1+T2)<1。

4. large aperture bugeye lens according to claim 1, is characterized in that: each surface of described first negative lens, the second negative lens, the 3rd positive lens, the 4th positive lens, the 5th negative lens and the 6th positive lens is aspheric surface.

5. large aperture bugeye lens according to claim 1, is characterized in that: described 5th negative lens adopts glass material eyeglass, and the first negative lens, the second negative lens, the 3rd positive lens, the 4th positive lens and the 6th positive lens adopt plastic material eyeglass.

6. large aperture bugeye lens according to claim 5, is characterized in that:

Refractive index n and the dispersion v scope of described first negative lens are respectively: 1.5 < n ₁< 1.6,50 < v ₁< 60;

Refractive index n and the dispersion v scope of described second negative lens are respectively: 1.5 < n ₂< 1.6,50 < v ₂< 60;

Refractive index n and the dispersion v scope of described 3rd positive lens are respectively: 1.5 < n ₂< 1.6,50 < v ₂< 60;

Refractive index n and the dispersion v scope of described 4th positive lens are respectively: 1.5 < n ₂< 1.6,50 < v ₂< 60;

Refractive index n and the dispersion v scope of described 5th negative lens are respectively: 1.6 < n ₄< 1.7,23 < v ₄< 25;

Refractive index n and the dispersion v scope of described 6th positive lens are respectively: 1.5 < n ₂< 1.6,50 < v ₂< 60.

7. the large aperture bugeye lens according to any one of claim 4, is characterized in that: described each lens non-spherical surface is even aspheric surface, and asphere coefficient meets following equation:

$z=\frac{{\mathrm{CY}}^2}{1+\sqrt{1-(1+k)C^2{Y}^2}}+\underset{i=2}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i{Y}^{2i}$

Wherein, i=2,3,4 ... N, z are the coordinates along optical axis direction, and Y is the radial coordinate in units of length of lens unit, and C is curvature (1/R), k is circular cone coefficient, α _ibe the coefficient of each high-order term, 2i is aspheric high power.

8. the large aperture bugeye lens according to any one of claim 4, is characterized in that: described each lens non-spherical surface can also be odd aspheric surface, and asphere coefficient meets following equation:

$z=\frac{{\mathrm{CY}}^2}{1+\sqrt{1-(1+k)C^2{Y}^2}}+\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_i{Y}^i$

Wherein, i=1,2,3,4 ... N, z are the coordinates along optical axis direction, and Y is the radial coordinate in units of length of lens unit, and C is curvature (1/R), k is circular cone coefficient, β _ibe the coefficient of each high-order term, i is aspheric high power.

9. the large aperture bugeye lens according to any one of claim 1-3, is characterized in that: be provided with aperture diaphragm between the 6th surface of described 3rd positive lens and the 7th surface of the 4th positive lens.

10. the large aperture bugeye lens according to any one of claim 1-3, is characterized in that: the image side on the 12 surface of described 6th positive lens is also provided with optical filter.