CN103676092B - A kind of high-pixel optical lens - Google Patents

Abstract

The present invention discloses a kind of high-pixel optical lens, is followed successively by front lens group, the diaphragm with positive focal power and has the rear lens group of positive focal power from object space to image space; Described front lens group is that first lens with negative power form with second lens with negative power, and has the 3rd lens composition of positive light coke; Described rear lens group is made up of one group of cemented doublet and the 6th lens with positive light coke.The optical lens that the present invention relates to, can realize distort little, size is little, high pass optical property and meet high definition require optical lens, and can ensure still to keep more perfect imaging definition in the temperature range of-40 DEG C ~+85 DEG C, be specially adapted to outdoor monitoring and in-vehicle camera system.

Description

A kind of high-pixel optical lens

Technical field

The present invention relates to a kind of high-pixel optical lens, be especially applicable in different temperatures, keep the monitoring of high-resolution or vehicle-mounted front view lens.

Background technology

Along with the development of auto industry active safety, require to improve constantly to vehicle-mounted front view lens, little, the miniaturization of distorting, high pixel, high-aperture lenses have been the necessary requirement of this type of camera lens.And require that camera lens keeps more perfect imaging definition in the temperature range of-40 DEG C ~+85 DEG C.

For arriving these requirements, front view lens introduces being designed in order to inevitable trend of aspherical lens.Simultaneously in order to reach the requirement of low cost, the aspherical lens in camera lens need use plastic aspherical element as far as possible.But glass lens is because temperature influence is very large, if improper use is difficult to ensure that different temperatures section remains the image request of high definition.

Summary of the invention

The technical matters that the present invention solves is, by the introducing of new optical texture, and focal power, lens materials refractive index vary with temperature the reasonable distribution of characteristic, use part aspherical lens simultaneously, a kind of camera lens remaining the ultra-wide working temperature of high-definition image is provided.

Technical matters of the present invention is solved by following technical proposals:

A kind of high-pixel optical lens, be followed successively by from object space to image space: the rear lens group of the front lens group of positive light coke, aperture member, positive light coke, described front lens group comprises first lens with negative power and second lens with negative power, and there are biconvex the 3rd lens of positive light coke, described first lens are bent moon or concave-concave eyeglass, and described second lens are bent moon eyeglasses of concave surface facing object space;

Described rear lens group comprises the 4th lens, the 5th lens and the 6th lens, and the 4th lens and the 5th lens form a cemented doublet, there are the 4th lens of the biconvex of positive focal power front, have the 5th lens of negative focal power rear, described 6th lens are the positive bent moon eyeglass of the concave surface facing object space with positive light coke or have the biconvex eyeglass of positive light coke.

Further, total field angle FOV of described optical lens will meet following formula:

80°≥FOV≥30°。

Further, described second lens are low negative power, adopt the eyeglass of this shape that the light after by first eyeglass is obtained stably excessively, have effectively corrected distortion and the curvature of field of system, and met the following conditions formula:

F2/F＜-3，Vd（2）＞40

The focal length of what wherein F2 represented is the second lens, F represents whole group of focal length value of the optical system of described optical lens, and Vd (2) is the Abbe number of the second lens, thus has further corrected aberration.

Further, described first lens meet the following conditions formula:

Nd（1）＜1.65，Vd（1）＞55

Wherein Nd(1) be the refractive index of the material of the first lens, Vd(1) be the Abbe constant of the material of the first lens.

Further, described 3rd lens meet the following conditions formula:

Nd（3）＞1.78，Vd（3）＞40

Wherein Nd(3) be the refractive index of the material of the 3rd lens, Vd(3) be the Abbe constant of the material of the 3rd lens.

Described 3rd lens meet Nd(3) > 1.78, and use high index of refraction eyeglass, realize the light that object space comes further and can excessively arrive rear group stably, and ensure the large aperture performance of camera lens, Vd(3) the axial chromatic aberation of the effective correction system of > 40.

Further, described 4th lens and the 5th lens meet:

Vd（4）＞55，Vd（5）＜30，

And gluing unit composition surface meets following condition formula:

5＞|R|/(Φ/2)＞2

Wherein, Vd(4) be the Abbe constant of the material of the 4th lens, Vd(5) be the Abbe constant of the material of the 5th lens, R is the center curvature radius on composition surface, and Φ is the light effective aperture on composition surface.

Described 4th lens and the 5th lens element adopt gummed design, effectively can improve the aberration of optical system.The composition surface simultaneously controlling cemented lens assembly meets 5 > | the condition formula of R|/(Φ/2) > 2, effectively to control the generation of senior aberration, thus be beneficial to the logical luminous energy power (aperture FNO≤1.8) and resolving power that improve whole optical system, and effectively reduce composition surface gluing technique requirement.

Further, by the reasonable distribution of camera lens focal power ratio, control the effective aperture of camera lens front end, and control the TTL of camera lens, described optical lens meets:

TTL/F＜5

Wherein, TTL represents the overall length of optical lens optical system, and F represents whole group of focal length value of the optical system of described optical lens.

Further, the maximum clear aperture of described first lens meets following condition formula with corresponding imaging image height, field angle:

D/h/FOV≤0.022

Wherein FOV represents the maximum field of view angle of camera lens, and D represents the maximum clear aperture of the first lens element corresponding to maximum field of view angle towards object space convex surface, and h represents the imaging image height corresponding to maximum field of view angle.

Further, the f-number of described optical lens meets following formula: FNO≤1.8.

For further realizing high pixel, need to introduce aspheric surface in camera lens composition, the introducing of Glass aspheric is relatively simple, if but adopt plastic aspherical element, because plastic aspherical element refractive index varies with temperature very large, need to adopt and reasonably select aspheric surface position and focal power to distribute, the resolution energy requirement that camera lens keeps high pixel in the temperature range of-40 DEG C ~+85 DEG C could be realized.

The present invention maintains the less eyeglass external diameter in front end, large aperture, the various aberrations of effective rectification optical system, realize high pixel, low cost, after achieving lens optical, Jiao varies with temperature simultaneously, and change with rear Jiao that structural member causes and cancel out each other, burnt compensating effect after realizing, makes camera lens keep more perfect imaging definition in the temperature range of working temperature-40 DEG C ~+85 DEG C.

Accompanying drawing explanation

Fig. 1 is the structural representation of embodiments of the invention 1;

Fig. 2 is the astigmatism curve map of embodiment 1;

Fig. 3 is the distortion curve figure of embodiment 1;

Fig. 4 is the out of focus curve of embodiment 1 central vision 45lp/mm-40 DEG C time;

Fig. 5 is the out of focus curve of embodiment 1 central vision 45lp/mm 20 DEG C time;

Fig. 6 is the out of focus curve of embodiment 1 central vision 45lp/mm 85 DEG C time.

Fig. 7 is the structural representation of embodiments of the invention 2;

Fig. 8 is the astigmatism curve map of embodiment 2;

Fig. 9 is the distortion curve figure of embodiment 2;

Figure 10 is the out of focus curve of embodiment 2 central vision 45lp/mm-40 DEG C time;

Figure 11 is the out of focus curve of embodiment 2 central vision 45lp/mm 20 DEG C time;

Figure 12 is the out of focus curve of embodiment 2 central vision 45lp/mm 85 DEG C time.

Embodiment

Be described in detail below in conjunction with accompanying drawing 1 pair of embodiments of the invention 1.

As shown in Figure 1, this optical lens is provided with front lens group, diaphragm L9, rear lens group, color filter L7, imaging surface L8 successively from object space, and described front lens group has positive focal power, and rear lens group has positive focal power.

Described front lens group is by the first lens L1 bent moon eyeglass with negative power and the second lens L2 of concave surface facing object space bent moon eyeglass with negative power, and biconvex the 3rd lens L3 with positive light coke forms;

Rear lens group, there is positive focal power, be made up of three lens units, the 4th lens L4, the 5th lens L5, the 6th lens L6 is followed successively by from object space to image space, and the 4th lens L4 and the 5th lens L5 forms a cemented doublet, 4th lens with the biconvex of positive focal power, front, have the 5th lens of negative focal power rear, and the 6th lens L6 is the positive bent moon eyeglass of the concave surface facing object space with positive light coke or has the biconvex eyeglass of positive light coke.

And wherein the second lens of pre-group are plastic aspherical elements, for Jiao after making optical system is compensated, select the 6th lens to be also plastic aspherical element eyeglass simultaneously, by the choose reasonable of two glass lens focal powers and refractive index temperature characteristic, after obtaining rational optics, burnt BFL " expands with heat and contract with cold " variable quantity.

From object space to image space, described first lens L1 two sides is S1, S2, second lens L2 two sides is S3, S4,3rd lens L3 two sides is S5, S6, diaphragm L9 is S7 face, and the 4th lens L4 two sides is S8, S9, and the 5th lens L5 two sides is S9, S10,6th lens L6 two sides is S11, S12, and optical filter L7 two sides is S13, S14.

And the formula of aspherical mirror is:

$Z\left(h\right)=\frac{{\mathrm{ch}}^2}{1+\sqrt{1-(1+k)c^2{h}^2}}+{\mathrm{Ah}}^4+{\mathrm{Bh}}^6+{\mathrm{Ch}}^8+{\mathrm{Dh}}^{10}+{\mathrm{Eh}}^{12}$

In formula: Z is aspheric surface along optical axis direction when the position highly for h, apart from the distance rise on aspheric surface summit.

C=1/r, r represent the radius-of-curvature of minute surface, and k is circular cone coefficient conic, and A, B, C, D, E are high order aspheric surface coefficient, and the e in coefficient represents scientific notation, as e-05 represents 10-5.

In embodiment 1, the whole focal length value of this optical lens is F, and f-number is FNO, and field angle is FOV, camera lens overall length TTL,

Table 1 is the parameter of the system of example 1:

F=4.82mmFNO=1.6FOV=70°TTL=19.1mm

Face sequence number	Radius-of-curvature r	Center thickness d	Refractive index Nd	Abbe constant Vd	Effective aperture D
						1	12.69495	0.6	1.517	64.2	6.41
2	3.121	2.866			4.91
						*3	-3.119	1.662	1.512	56.3	4.74
*4	-3.906	0.1			5.60
						5	9.516	3.249	1.804	46.6	5.58
6	-9.516	-0.2			4.93
						7	Infinity	0.3			4.78
8	7.22	1.983	1.696	55.5	4.78
						9	-7.22	0.6	1.847	23.8	4.43
10	5.6	1.05			4.14
						*11	-26.213	2.2	1.535	56.1	4.34
*12	-4.403	0.1			5.21
						13	Infinity	0.55	1.517	64.2	5.29
14	Infinity	4.045			5.32
						IMA	Infinity				6

That following table is listed is asphericity coefficient K, A, B, C, D, E:

In this example | R|/(Φ/2)=3.25, TTL/F=3.96, D/h/FOV=0.015.

Fig. 2 to Fig. 6 is the optical performance curve figure corresponding to embodiment 1, and wherein Fig. 2 is astigmatism curve map, by the F commonly used, d, C tri-the wavelength of coloured light represent, unit is mm.Fig. 3 is distortion curve figure, must be distorted under representing different field angle situation sizes values, unit is %, Fig. 4 ~ Fig. 6 is that optical lens is respectively at temperature-40 DEG C, the MTF out of focus curve of central vision of 20 DEG C, 85 DEG C, black thick-line arrow represents the position of the peak value of out of focus curve, obtain optics from these three figure after, burnt BFL varies with temperature " expanding with heat and contract with cold ", usually can adopt the plastic feet that thermal expansivity CTE is large according to this system BFL variation with temperature amount result.Burnt compensate function after realizing, makes optical lens keep more perfect imaging definition in the temperature range of working temperature-40 DEG C ~+85 DEG C.

Be described in detail below in conjunction with accompanying drawing 7 pairs of embodiments of the invention 2.

As shown in Figure 7, this optical lens is provided with front lens group, diaphragm L9, rear lens group, color filter L7, imaging surface L8 successively from object space, and described front lens group has positive focal power, and rear lens group has positive focal power.

Described front lens group is by the first lens L1 bent moon eyeglass with negative power and the second lens L2 of concave surface facing object space bent moon eyeglass with negative power, and biconvex the 3rd lens L3 with positive light coke forms;

Rear lens group, it has positive focal power, be made up of three lens units, the 4th lens L4, the 5th lens L5, the 6th lens L6 is followed successively by from object space to image space, and the 4th lens L4 and the 5th lens L5 forms a cemented doublet, the 4th lens L4 with the biconvex of positive focal power, front, has the 5th lens L5 of negative focal power rear, and the 6th lens L6 is the positive bent moon eyeglass of the concave surface facing object space with positive light coke or has the biconvex eyeglass of positive light coke.Wherein the 6th lens are Glass aspheric.

From object space to image space, described first lens L1 two sides is S1, S2, second lens L2 two sides is S3, S4,3rd lens L3 two sides is S5, S6, diaphragm L9 is S7 face, and the 4th lens L4 two sides is S8, S9, and the 5th lens L5 two sides is S9, S10,6th lens L6 two sides is S11, S12, and optical filter L7 two sides is S13, S14.

And the formula of aspherical mirror is:

$Z\left(h\right)=\frac{{\mathrm{ch}}^2}{1+\sqrt{1-(1+k)c^2{h}^2}}+{\mathrm{Ah}}^4+{\mathrm{Bh}}^6+{\mathrm{Ch}}^8+{\mathrm{Dh}}^{10}+{\mathrm{Eh}}^{12}$

In formula: Z is aspheric surface along optical axis direction when the position highly for h, apart from the distance rise on aspheric surface summit.

C=1/r, r represent the radius-of-curvature of minute surface, and k is circular cone coefficient conic, and A, B, C, D, E are high order aspheric surface coefficient, and the e in coefficient represents scientific notation, as e-05 represents 10-5.

Table 2 is the parameter of the system of example 2:

F=4.85mmFNO=1.5FOV=70°TTL=19.45mm

Face sequence number	Radius-of-curvature r	Center thickness d	Refractive index Nd	Abbe constant Vd	Effective aperture D
						1	14.841	0.6	1.517	64.2	7.26
2	3.167	3.052			5.46
						3	-4.086	1.741	1.804	46.6	5.34
4	-5.480	0.1			6.37
						5	12.75	1.830	1.772	49.6	6.38
6	-10.99	0.057			6.08
						7	Infinity	1.114			5.65
8	7.455	1.950	1.497	81.5	5.85
						9	-7.455	0.6	1.785	25.7	5.70
10	7.093	0.708			5.64
						*11	14.232	1.773	1.743	49.3	5.77
*12	-7.596	0.1			6.31
						15	Infinity	0.4	1.517	64.2	6.05
16	Infinity	5.24			6.04
						IMA	Infinity				6

That following table is listed is asphericity coefficient K, A, B, C, D, E:

Face sequence number

K

A

B

C

D

E

11

19.01586

-0.0020793344

5.5957559e-005

-8.1949736e-005

1.1627235e-005

-8.3665806e-007

12

-4.836767

0.00025672364

-9.8425327e-005

-1.0749914e-005

1.59402e-006

-1.6157054e-007

In this example | R|/(Φ/2)=2.6, TTL/F=4.0, D/h/FOV=0.017.

Fig. 8 to Figure 12 is the optical performance curve figure corresponding to case study on implementation, and wherein Fig. 8 is astigmatism curve map, by the F commonly used, d, C tri-the wavelength of coloured light represent, unit is mm.Fig. 9 is distortion curve figure, must be distorted under representing different field angle situation sizes values, unit is %, Figure 10 ~ Figure 12 is that optical lens is respectively temperature-40 DEG C, 20 DEG C, the MTF out of focus curve of the central vision of 85 DEG C, black thick-line arrow represents the position of the peak value of out of focus curve, obtain optics from these three figure after, burnt BFL varies with temperature " expanding with heat and contract with cold ", but variable quantity is less than example 1, usually the plastic feet or metab that thermal expansivity CTE is little can be adopted according to this system BFL variation with temperature amount result, burnt compensate function after realizing, optical lens is made to keep more perfect imaging definition in the temperature range of working temperature-40 DEG C ~+85 DEG C.

Claims (9)

1. a high-pixel optical lens, it is characterized in that, be followed successively by from object space to image space: the rear lens group of the front lens group of positive light coke, aperture member, positive light coke, described front lens group comprises first lens with negative power and second lens with negative power, and there are biconvex the 3rd lens of positive light coke, described first lens are bent moon or concave-concave eyeglass, and described second lens are bent moon eyeglasses of concave surface facing object space;

Described rear lens group comprises the 4th lens, the 5th lens and the 6th lens, and the 4th lens and the 5th lens form a cemented doublet, there are the 4th lens of the biconvex of positive focal power front, have the 5th lens of negative focal power rear, described 6th lens are the positive bent moon eyeglass of the concave surface facing object space with positive light coke or have the biconvex eyeglass of positive light coke.

2. high-pixel optical lens according to claim 1, is characterized in that: total field angle FOV of described optical lens will meet following formula:

80°≥FOV≥30°。

3. high-pixel optical lens according to claim 1, is characterized in that:

Described second lens are low negative power, meet the following conditions formula:

F2/F＜-3，Vd（2）＞40

The focal length of what wherein F2 represented is the second lens, F represents whole group of focal length value of the optical system of described optical lens, and Vd (2) is the Abbe number of the second lens.

4. high-pixel optical lens according to claim 1, is characterized in that:

Described first lens meet the following conditions formula:

Nd（1）＜1.65，Vd（1）＞55

Wherein Nd(1) be the refractive index of the material of the first lens, Vd(1) be the Abbe constant of the material of the first lens.

5. high-pixel optical lens according to claim 1, is characterized in that:

Described 3rd lens meet the following conditions formula:

Nd（3）＞1.78，Vd（3）＞40

Wherein Nd(3) be the refractive index of the material of the 3rd lens, Vd(3) be the Abbe constant of the material of the 3rd lens.

6. high-pixel optical lens according to claim 1, is characterized in that: described 4th lens and the 5th lens meet:

Vd（4）＞55，Vd（5）＜30，

And gluing unit composition surface meets following condition formula:

5＞|R|/(Φ/2)＞2

Wherein, Vd(4) be the Abbe constant of the material of the 4th lens, Vd(5) be the Abbe constant of the material of the 5th lens, R is the center curvature radius on composition surface, and Φ is the light effective aperture on composition surface.

7. high-pixel optical lens according to claim 1, is characterized in that: described optical lens meets:

TTL/F＜5

Wherein, TTL represents the overall length of optical lens optical system, and F represents whole group of focal length value of the optical system of described optical lens.

8. high-pixel optical lens according to claim 1, is characterized in that: maximum clear aperture and corresponding imaging image height, the field angle of described first lens meet following condition formula:

D/h/FOV≤0.022

Wherein FOV represents the maximum field of view angle of camera lens, and D represents the maximum clear aperture of the first lens element corresponding to maximum field of view angle towards object space convex surface, and h represents the imaging image height corresponding to maximum field of view angle.

9. high-pixel optical lens according to claim 1, is characterized in that: the f-number of described optical lens meets following formula: FNO≤1.8.