CN114911040A

CN114911040A - Infrared lens and infrared lens module

Info

Publication number: CN114911040A
Application number: CN202210499920.7A
Authority: CN
Inventors: 廖仁泽; 王�锋; 周明明; 马庆鸿; 万良伟
Original assignee: Huizhou Xingjuyu Optical Co ltd
Current assignee: Huizhou Xingjuyu Optical Co ltd
Priority date: 2022-05-09
Filing date: 2022-05-09
Publication date: 2022-08-16
Anticipated expiration: 2042-05-09
Also published as: CN114911040B

Abstract

The invention discloses an infrared lens and an infrared lens module, belonging to the technical field of optical imaging, and comprising the following components in sequence from an object side to an image side along an optical axis: a first lens having a negative power, a second lens having a positive power, a third lens having a positive power, a fourth lens having a positive power, a fifth lens having a negative power, and a sixth lens having a positive power, an object side surface of which is convex near an optical axis; the infrared lens meets the following conditional expression: 27.782< (tanHFOV x TTL)/(SAG21+ SAG22) <39.742, the total length of the infrared lens can be shortened on the premise that the HFOV is larger, thereby being beneficial to meeting the miniaturization of the infrared lens; in addition, the distortion of the infrared lens is improved, and the imaging quality of the infrared lens is improved.

Description

Infrared lens and infrared lens module

Technical Field

The invention relates to the technical field of optical imaging, in particular to an infrared lens and an infrared lens module.

Background

The lens in the fields of aerial photography, monitoring, vehicle-mounted and the like is often required to have a larger shooting range, and meanwhile, the details of a shot object need to be captured more accurately in the shooting process, so that the imaging quality of the lens is required to be higher. In addition, with the advance of lens technology, people also require the development of the lens in the above field to be light and thin so as to adapt to more shooting environments and better carry on the device. Therefore, it is a problem to be solved in the art to design a large wide-angle, high-quality, and small-sized lens.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide an infrared lens and an infrared lens module, which meet the requirements of large wide angle, high imaging quality and miniaturization.

In a first aspect, an infrared lens includes, in order from an object side to an image side along an optical axis:

a first lens having a negative optical power, an image-side surface of which is concave near an optical axis;

a second lens having a positive optical power, an object-side surface of which is convex near the optical axis;

a third lens having a positive optical power, an object-side surface of which is convex near the optical axis;

a fourth lens having positive optical power, an image-side surface of which is convex near the optical axis;

a fifth lens having a negative optical power, an object-side surface of which is convex near the optical axis; and

a sixth lens having a positive optical power, an object-side surface of which is convex near the optical axis;

the infrared lens meets the following conditional expression: 27.782< (tanHFOV x TTL)/(SAG21+ SAG22) < 39.742.

In one embodiment, the infrared lens satisfies the following conditional expression: 0.551< D26/TTL < 0.567.

In one embodiment, the infrared lens satisfies the following conditional expression:

51.260<(DT11-DT12)/(SAG12-SAG11)<134.234。

in one embodiment, the infrared lens satisfies the following conditional expression: 24.616< f456/(T45+ T56) < 28.525.

4.767<(f234+f56)/(CT2+CT3+CT4+CT5+CT6)<8.543。

in one embodiment, the infrared lens satisfies the following conditional expression: 3.324< (f6-f1)/f < 3.451.

37.800<(DT52+DT61)/(SAG52-SAG61)<56.002。

in one embodiment, the infrared lens satisfies the following conditional expression: 0.719< | R41+ R42|/f4< 0.768.

In one embodiment, the image side surface of the fifth lens comprises at least three points of inflection.

In a second aspect, an infrared lens module is provided, which includes the infrared lens in any one of the possible implementation manners of the first aspect.

The invention has the beneficial effects that:

the image side surface of the first lens with negative focal power is a concave surface close to the optical axis, so that light rays at the edge of the first lens in the height direction can enter the infrared lens through the first lens, the field angle of the infrared lens can be increased, and the effect of a large wide angle is obtained; in addition, on the premise of a large visual angle, more light rays enter the optical lens, the light transmission quantity is increased, and the illumination intensity is improved, so that the imaging quality of the infrared lens is improved; when 27.782< (tanHFOV x TTL)/(SAG21+ SAG22) <39.742 is satisfied, on the premise that the HFOV is large, the ratio of the rise of the object side and the image side of the first lens to the total length of the infrared lens is controlled, the total length of the infrared lens can be shortened, and the infrared lens can be miniaturized; in addition, the curvature degree of the object side and the image side of the first lens is controlled by controlling the rise of the object side and the rise of the side of the first lens, so that the distortion of the infrared lens is improved, and the imaging quality of the infrared lens is improved.

Drawings

Fig. 1 is a schematic structural diagram of an infrared lens according to a first embodiment of the present application;

fig. 2 to 5 are a spherical aberration graph, an astigmatism graph, a distortion graph and a magnification chromatic aberration graph of an infrared lens according to an embodiment of the present application in sequence;

fig. 6 is a schematic structural diagram of an infrared lens according to a second embodiment of the present application;

fig. 7 to 10 are a spherical aberration graph, an astigmatism graph, a distortion graph and a magnification chromatic aberration graph of the second infrared lens according to the second embodiment of the present application in sequence;

fig. 11 is a schematic structural view of an infrared lens according to a third embodiment of the present application;

fig. 12 to fig. 15 are a spherical aberration graph, an astigmatism graph, a distortion graph and a magnification chromatic aberration graph of the three infrared lenses according to the embodiment of the present application in sequence;

fig. 16 is a schematic structural view of an infrared lens according to a fourth embodiment of the present application;

fig. 17 to 20 are a spherical aberration graph, an astigmatism graph, a distortion graph and a magnification chromatic aberration graph of the four infrared lenses according to the embodiment of the present application in sequence;

fig. 21 is a schematic structural diagram of an infrared lens according to a fifth embodiment of the present application;

fig. 22 to 25 are a spherical aberration graph, an astigmatism graph, a distortion graph and a magnification chromatic aberration graph of a five-infrared lens according to an embodiment of the present application in sequence;

fig. 26 is a schematic structural view of an infrared lens according to a sixth embodiment of the present application;

fig. 27 to 30 are a spherical aberration graph, an astigmatism graph, a distortion graph and a magnification chromatic aberration graph of the six infrared lenses according to the embodiment of the present application in sequence.

In the figure: 100. an infrared lens; 101. a first lens; 102. a second lens; 103. a third lens; 104. a fourth lens; 105. a fifth lens; 106. a sixth lens; 107. an optical filter; 108. an image sensor.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

For convenience of understanding, technical terms related to the present application are explained and described below.

TTL is the distance from the object side surface of the first lens to the imaging surface of the infrared lens on the optical axis;

the FOV is the maximum field angle of the infrared lens; the HFOV is half of the maximum field angle of the infrared lens;

F.No is the diaphragm F value of the infrared lens; f is the total effective focal length of the infrared lens;

f1 is the effective focal length of the first lens; f4 is the effective focal length of the fourth lens;

f6 is the effective focal length of the sixth lens; f234 is the combined focal length of the second lens, the third lens and the fourth lens;

f56 is the combined focal length of the fifth lens and the sixth lens; f456 is a combined focal length of the fourth lens, the fifth lens and the sixth lens;

CT2 is the central thickness of the second lens on the optical axis; CT3 is the central thickness of the third lens on the optical axis;

CT4 is the center thickness of the fourth lens on the optical axis; CT5 is the center thickness of the fifth lens on the optical axis;

CT6 is the central thickness of the sixth lens on the optical axis; r41 is the radius of curvature of the object-side surface of the fourth lens;

r42 is the radius of curvature of the image-side surface of the fourth lens element; DT11 is the maximum effective radius of the object side of the first lens;

DT12 is the maximum effective radius of the image-side surface of the first lens; DT52 is the maximum effective radius of the image side surface of the fifth lens;

DT61 is the maximum effective radius of the object-side surface of the sixth lens; t45 is the distance between the fourth lens and the fifth lens on the optical axis;

t56 is the distance between the fifth lens and the sixth lens on the optical axis;

d26 is the distance on the optical axis from the object-side surface of the second lens element to the image-side surface of the sixth lens element;

SAG11 is the distance on the optical axis from the intersection point of the object side surface of the first lens and the optical axis to the effective radius vertex of the object side surface of the first lens;

SAG12 is the distance on the optical axis from the intersection point of the image side surface of the first lens and the optical axis to the effective radius vertex of the image side surface of the first lens;

SAG21 is the distance on the optical axis from the intersection point of the object side surface of the second lens and the optical axis to the effective radius vertex of the object side surface of the second lens;

SAG22 is the distance on the optical axis from the intersection point of the image side surface of the second lens and the optical axis to the effective radius vertex of the image side surface of the second lens;

SAG61 is the distance on the optical axis from the intersection point of the object side surface of the sixth lens and the optical axis to the effective radius vertex of the object side surface of the sixth lens;

SAG52 is the distance on the optical axis from the intersection point of the image side surface of the fifth lens and the optical axis to the effective radius vertex of the image side surface of the fifth lens.

As shown in fig. 1, an infrared lens 100 according to an embodiment of the present application includes 6 lenses. For convenience of description, the left side of the infrared lens 100 is defined as the object side (hereinafter also referred to as the object side), the surface of the lens facing the object side can be referred to as the object side surface, the surface of the lens facing the object side can be also referred to as the surface of the lens near the object side, the right side of the infrared lens 100 is defined as the image side (hereinafter also referred to as the image side), the surface of the lens facing the image side can be referred to as the image side surface, and the image side surface can be also referred to as the surface of the lens near the image side. From the object side to the image side, the infrared lens 100 of the embodiment of the present application sequentially includes: a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106; a diaphragm may also be disposed between the second lens 102 and the third lens 103. An image sensor 108, such as a CCD, CMOS, etc., may also be disposed after the sixth lens 106. A filter 107, such as a flat infrared cut filter, may also be disposed between the sixth lens 106 and the image sensor 108. The infrared lens 100 is described in detail below.

It should be noted that, for convenience of understanding and description, the embodiment of the present application defines a representation form of relevant parameters of the infrared lens, for example, TTL represents a distance from an object side surface of the first lens element to an imaging surface of the infrared lens on an optical axis; ImgH represents the maximum image height of the infrared lens, and the letter representation of similar definition is only schematic, but can be represented in other forms, and the application is not limited in any way.

It should be noted that the units of the parameters related to the ratio in the following relational expression are consistent, for example, the units of numerator are millimeters (mm), and the units of denominator are also millimeters (mm).

The positive and negative of the curvature radius indicate that the optical surface is convex toward the object side or convex toward the image side, and when the optical surface (including the object side surface or the image side surface) is convex toward the object side, the curvature radius of the optical surface is a positive value; when the optical surface (including the object side surface or the image side surface) is convex toward the image side, the optical surface is concave toward the object side, and the radius of curvature of the optical surface is negative.

It should be noted that the shape of the lens, and the degree of the concave-convex of the object side surface and the image side surface in the drawings are only schematic, and do not limit the embodiments of the present application. In this application, the material of the lens may be resin (resin), plastic (plastic), or glass (glass). The lens includes a spherical lens and an aspherical lens. The lens can be a fixed focal length lens or a zoom lens, and can also be a standard lens, a short-focus lens or a long-focus lens.

Referring to fig. 1, a dotted line in fig. 1 is used to indicate an optical axis of the lens.

The infrared lens 100 of the present embodiment includes, in order from an object side to an image side along an optical axis: a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106.

Alternatively, in the embodiments of the present application,

the first lens 101 may have a negative power, the object side S1 of the first lens 101 being convex near the optical axis; the image-side surface S2 of the first lens 101 is concave near the optical axis;

the second lens 102 can have positive optical power, the object side surface S3 of the second lens 102 being convex near the optical axis, the image side surface S4 of the second lens 102 being concave near the optical axis;

the third lens 103 may have positive optical power, an object-side surface S5 of the third lens 103 being convex near the optical axis, and an image-side surface S6 of the third lens 103 being convex near the optical axis;

the fourth lens 104 may have positive optical power, the object side surface S7 of the fourth lens 104 being concave near the optical axis, the image side surface S8 of the fourth lens 104 being convex near the optical axis;

the fifth lens 105 may have a negative power, an object-side surface S9 of the fifth lens 105 being convex near the optical axis, and an image-side surface S10 of the fifth lens 105 being concave near the optical axis;

the sixth lens 106 may have positive optical power, with the object side surface S11 of the sixth lens 106 being convex near the optical axis and the image side surface S12 of the sixth lens 106 being concave near the optical axis.

The infrared lens 100 satisfies the following relation: 27.782< (tanHFOV x TTL)/(SAG21+ SAG22) < 39.742; preferably 28.271< (tanHFOV × TTL)/(SAG21+ SAG22) <39.048, more preferably 29.772< (tanHFOV × TTL)/(SAG21+ SAG22) < 31.807; the image side surface of the first lens with negative focal power is a concave surface close to the optical axis, so that light rays at the edge of the first lens in the height direction can enter the infrared lens through the first lens, the field angle of the infrared lens can be increased, and the effect of a large wide angle is obtained; in addition, on the premise of a large visual angle, more light rays enter the optical lens, the light transmission quantity is increased, and the illumination intensity is improved, so that the imaging quality of the infrared lens is improved; when 27.782< (tanHFOV × TTL)/(SAG21+ SAG22) <39.742 is satisfied, on the premise that the HFOV is large, the ratio of the rise of the object side and the image side of the first lens to the total length of the infrared lens is controlled, and the total length of the infrared lens can be shortened, thereby contributing to the satisfaction of miniaturization of the infrared lens; in addition, the curvature degree of the object side and the image side of the first lens is controlled by controlling the rise of the object side and the rise of the side of the first lens, so that the distortion of the infrared lens is improved, and the imaging quality of the infrared lens is improved. When the optimal and more optimal conditions are met, the requirements of large wide angle, miniaturization and high imaging quality of the infrared lens can be better met.

In certain implementations of the first aspect, the infrared lens satisfies the following conditional expression: 0.551< D26/TTL < 0.567; preferably 0.554< D26/TTL < 0.565; the ratio of the distance from the object side surface of the second lens to the image side surface of the sixth lens on the optical axis to the total length of the lens group is controlled, so that the structure among the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens is kept compact, and the miniaturization of the infrared lens is further facilitated. When the optimal conditions are met, the miniaturization requirement of the infrared lens can be better met.

In certain implementations of the first aspect, the infrared lens satisfies the following conditional expression: 51.260< (DT11-DT12)/(SAG12-SAG11) < 134.234; preferably 56.279< (DT11-DT12)/(SAG12-SAG11) <103.458, more preferably 77.623< (DT11-DT12)/(SAG12-SAG11) < 86.861; the difference of the maximum effective radius of the object side surface of the first lens and the maximum effective radius of the first transparent mirror image side surface is controlled, the bending degree of the object side surface and the image side surface of the first lens is controlled to be smaller, so that light rays are more gentle when entering the second lens after being refracted by the first lens, the distortion of the infrared lens is favorably reduced, and the stability of the imaging quality of the infrared lens is improved. The rise of the object side surface of the first lens and the rise of the image side surface of the first lens are controlled, so that ghost images at two ends of the first lens can be effectively improved, and the imaging quality of the infrared lens is improved; the difference between the rise of the object side surface of the first lens and the rise of the image side surface of the first lens is controlled, so that the bending degree of the first lens is controlled within a reasonable range, the processing performance of the first lens is optimized, the production yield of the first lens is improved, and the production yield of the infrared lens is improved. When the optimal and more optimal conditions are met, the high imaging quality requirement of the infrared lens can be better met, and the production yield of the infrared lens can be better improved.

In certain implementations of the first aspect, the infrared lens satisfies the following conditional expression: 24.616< f456/(T45+ T56) < 28.525; preferably 24.953< f456/(T45+ T56) <27.611, more preferably 26.858< f456/(T45+ T56) <27.611, by controlling the combined focal length of the fourth lens, the fifth lens, and the sixth lens, the distance between the fourth lens and the fifth lens on the optical axis, and the distance between the fifth lens and the sixth lens on the optical axis, the structure between the fourth lens, the fifth lens, and the sixth lens is made more compact, which is further advantageous for miniaturization of the infrared lens. When the preferable and more preferable conditions are satisfied, the miniaturization requirement of the infrared lens can be better satisfied.

In certain implementations of the first aspect, the infrared lens satisfies the following conditional expression:

4.767< (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) < 8.543; preference is given to

4.845< (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) <7.184, more preferably

4.948< (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) <5.984, the combined focal length of the second lens, the third lens and the fourth lens and the combined focal length of the fifth lens and the sixth lens are controlled, so that the focal lengths between the lens group of the second lens, the third lens and the fourth lens and the lens group of the fifth lens and the sixth lens are reasonably distributed, the system chromatic aberration of the infrared lens can be effectively corrected, the distortion and the coma are improved, the resolution of the infrared lens is improved, and the imaging quality is further improved. When the optimal and more preferable conditions are met, the requirement of high imaging quality of the infrared lens can be better met.

In certain implementations of the first aspect, the infrared lens satisfies the following conditional expression: 3.324< (f6-f1)/f <3.451, preferably 3.385< (f6-f1)/f <3.446, more preferably 3.395< (f6-f1)/f < 3.410; the ratio of the difference value of the effective focal length of the sixth lens and the effective focal length of the first lens to the total effective focal length of the infrared lens is reasonably distributed, so that the reasonable distribution of the focal lengths of the first lens and the sixth lens is facilitated, the system chromatic aberration of the infrared lens can be effectively corrected, the distortion and the coma are improved, the resolution of the infrared lens is improved, and the imaging quality is further improved; meanwhile, the ratio of the focal length difference value of the first lens and the sixth lens to the total effective focal length of the infrared lens is controlled within a reasonable range, the process sensitivity of the infrared lens is reduced, and the yield of lens production is improved. When the optimal and more optimal conditions are met, the requirement of high imaging quality of the infrared lens can be better met, and meanwhile, the production yield of the infrared lens can be better improved.

In certain implementations of the first aspect, the infrared lens satisfies the following conditional expression: 37.800< (DT52+ DT61)/(SAG52-SAG61) < 56.002; preferably 44.012< (DT52+ DT61)/(SAG52-SAG61) <50.330, more preferably 45.441< (DT52+ DT61)/(SAG52-SAG61) <47.944, the maximum effective radius and the saggital height of the image side surface of the fifth lens and the maximum effective radius and the saggital height of the object side surface of the sixth lens are controlled, so that the light rays of the image side surface of the fifth lens enter the light rays of the object side surface of the sixth lens, the transition is smooth, the sensitivity of the infrared lens system is reduced, and the stability of the imaging quality of the infrared lens is improved; in addition, the difference value of the rise of the image side surface of the fifth lens and the rise of the object side surface of the sixth lens is controlled, so that the bending degrees of the image side surface of the fifth lens and the object side surface of the sixth lens are uniform and unified, the adaptation degree of the fifth lens and the sixth lens is improved, the fifth lens and the sixth lens are assembled more reasonably, and the manufacturing yield of the infrared lens is improved. When the optimal and more optimal conditions are met, the stability of the high imaging quality of the infrared lens can be better improved, and meanwhile, the manufacturing yield of the infrared lens can be better improved.

In certain implementations of the first aspect, the infrared lens satisfies the following conditional expression: 0.719< | R41+ R42|/f4<0.768, preferably 0.732< | R41+ R42|/f4<0.766, more preferably 0.745< | R41+ R42|/f4<0.751, and controlling the ratio of the sum of the object-side and image-side curvature radii of the fourth lens to the focal length of the fourth lens to make the matching degree of the curvature radii of the object-side and the image-side of the fourth lens to the focal length of the fourth lens higher, which is beneficial to controlling the contribution rate of the fourth lens to the spherical aberration of the infrared lens, thereby further improving the imaging quality of the infrared lens. When the optimal and more optimal conditions are met, the requirement of high imaging quality of the infrared lens can be better met.

In certain implementations of the first aspect, the image-side surface of the fifth lens element includes at least three inflection points, which is advantageous for optimizing aberration and improving imaging quality of the infrared lens element.

In a second aspect, the present invention further provides an infrared lens module, which includes the infrared lens in any one of the possible implementation manners of the first aspect, and may further include an image sensor, an analog-to-digital converter, an image processor, a memory, and the like, to implement a camera function of the infrared lens.

Some specific, non-limiting examples of embodiments of the present application will be described in more detail below in conjunction with fig. 1-30.

In the embodiment of the present application, the material of each lens of the infrared lens 100 is not specifically limited.

Example one

The infrared lens 100 according to one embodiment of the present application includes, in order from an object side to an image side: a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106, as shown in fig. 1.

For convenience of description, in the following embodiments, STO denotes a surface of a stop, S1 denotes an object-side surface of the first lens 101, S2 denotes an image-side surface of the first lens 101, S3 denotes an object-side surface of the second lens 102, S4 denotes an image-side surface of the second lens 102, S5 denotes an object-side surface of the third lens 103, S6 denotes an image-side surface of the third lens 103, S7 denotes an object-side surface of the fourth lens 104, S8 denotes an image-side surface of the fourth lens 104, S9 denotes an object-side surface of the fifth lens 105, S10 denotes an image-side surface of the fifth lens 105, S11 denotes an object-side surface of the sixth lens 106, S12 denotes an image-side surface of the sixth lens 106, S13 denotes an object-side surface of a filter, S14 denotes an image-side surface of the filter, and S15 denotes an imaging surface. TTL denotes an optical total length of the infrared lens 100, ImgH denotes a maximum image height of the infrared lens 100, and EFL denotes an effective focal length of the infrared lens 100. The ith order aspheric coefficients are represented by α i, i is 4, 6, 8, 10, 12, 14, 16, and the cone coefficients are represented by K.

In light of the above relations, table 1 shows the effective focal length EFL, the maximum field angle FOV, the total optical length TTL, the F-number f.no, the surface type, the curvature radius, the thickness, the refractive index of the material, and the conic coefficient of the infrared lens 100 in the first embodiment, where the curvature radius and the thickness are both in millimeters (mm), as shown in table 1:

TABLE 1

Table 2 shows aspheric coefficients of the infrared lens 100 according to the first embodiment of the present application, as shown in table 2:

TABLE 2

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

5.294E-03

2.911E-04

1.435E-07

8.033E-07

2.397E-07

3.792E-08

-4.666E-09

S2

-2.199E-02

-4.170E-02

-3.153E-03

-1.595E-03

-5.789E-04

1.364E-03

-2.781E-04

S3

-1.360E-01

-7.855E-02

1.909E-01

-7.473E-02

-6.406E-02

7.318E-02

-2.024E-02

S4

3.623E-01

-5.955E-01

2.060E+00

5.437E+00

-1.359E+01

-5.080E+01

1.442E+02

S5

8.111E-02

1.013E-01

7.252E-01

-4.239E+00

-1.848E+01

1.343E+02

-1.904E+02

S6

-3.133E-01

-2.427E-01

4.549E-01

-2.366E+00

7.673E-01

6.540E+00

-3.842E+00

S7

-6.161E-01

1.385E+00

-5.021E+00

5.103E+00

3.866E+00

-2.844E+01

2.825E+01

S8

-1.402E-02

3.944E-01

-2.655E-01

-2.980E-01

2.743E-01

2.980E-01

-2.232E-01

S9

-1.287E-02

-3.245E-03

-2.830E-04

5.412E-04

-2.332E-04

-3.652E-04

1.953E-05

S10

-8.836E-02

1.176E-02

8.593E-03

1.322E-03

-1.130E-03

-4.522E-04

1.389E-04

S11

-9.362E-02

2.299E-03

2.689E-03

-8.926E-04

1.475E-04

1.674E-04

-3.672E-05

S12

-5.968E-02

1.293E-02

-1.255E-03

-5.485E-04

-4.344E-05

2.477E-05

1.955E-06

Wherein, the non-curved surface of each lens of the infrared lens 100 satisfies:

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/r (i.e., paraxial curvature c is the inverse of radius of curvature r in table 1 above); k is the conic constant (given in table 1 above); ai is a correction coefficient of the i-n th order of the aspherical surface, and the coefficients of the high-order terms a4, a6, A8, a10, a12, a14, and a16 of the respective lens surfaces S1 through S12 are shown in table 2.

It should be understood that the aspheric surfaces of the lenses in the infrared lens 100 may use the aspheric surface shown in the above aspheric surface formula, and may also use other aspheric surface formulas, which are not limited in this application.

Given the design data of the infrared lens 100 according to the first embodiment of the present application, the effective focal length EFL is 1.170mm, the maximum field angle FOV is 124.874 degrees, the total optical length TTL is 5.977mm, and the F-stop F value f.no is 2.106.

In one embodiment provided herein, (tanHFOV × TTL)/(SAG21+ SAG22) ═ 27.782.

In one embodiment provided herein, D26/TTL is 0.562.

In one example provided herein, (DT11-DT12)/(SAG12-SAG11) ═ 134.234.

In one embodiment provided herein, f456/(T45+ T56) is 27.611.

In one embodiment provided herein, (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) is 8.543.

In one embodiment provided herein, (f6-f1)/f 3.395.

In one example provided herein, (DT52+ DT61)/(SAG52-SAG61) ═ 47.944.

In one embodiment provided herein, | R41+ R42|/f4 ═ 0.732.

Fig. 2 to 5 illustrate the optical performance of the infrared lens 100 designed in such a lens combination according to the embodiment.

In the first embodiment, the infrared lens meets the requirements of large wide angle, high imaging quality and miniaturization.

Example two

The infrared lens 100 of an embodiment of the present application, in order from an object side to an image side, includes: a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106, as shown in fig. 6.

In light of the above relations, table 3 shows the effective focal length EFL, the maximum field angle FOV, the total optical length TTL, the F-number f.no, the surface type, the curvature radius, the thickness, the refractive index of the material, and the conic coefficient of the infrared lens 100 in the second embodiment, where the curvature radius and the thickness are both in millimeters (mm), as shown in table 3:

TABLE 3

Table 4 shows aspheric coefficients of the infrared lens 100 according to the second embodiment of the present application, as shown in table 4:

TABLE 4

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

3.694E-03

8.862E-05

2.808E-05

1.230E-06

-3.734E-07

-2.476E-08

7.037E-09

S2

-2.213E-02

-5.154E-02

-7.008E-04

-1.116E-03

9.464E-05

1.778E-03

-4.132E-04

S3

-9.721E-02

-5.442E-02

9.361E-02

4.279E-02

-2.617E-02

-7.441E-03

-4.797E-04

S4

3.176E-01

-3.273E-01

1.967E+00

3.150E-02

-5.130E+00

-6.373E+00

4.174E+01

S5

5.561E-02

2.297E-01

3.763E-01

-5.104E+00

-1.078E+01

1.002E+02

-1.498E+02

S6

-2.531E-01

2.864E-02

3.995E-01

-3.063E+00

2.184E+00

1.274E+01

-1.687E+01

S7

-6.095E-01

9.264E-01

-3.835E+00

8.619E-01

6.101E+00

-8.450E+00

-1.151E+01

S8

3.681E-02

1.065E-01

-6.020E-02

-1.459E-01

1.755E-01

2.195E-01

-1.417E-01

S9

-3.827E-02

1.051E-02

3.864E-03

-1.667E-03

-7.998E-04

3.169E-04

-2.382E-05

S10

-8.022E-02

5.558E-03

3.096E-03

7.293E-04

-2.417E-04

-1.719E-04

2.318E-05

S11

-8.963E-02

-1.080E-02

7.407E-04

9.763E-04

2.916E-04

3.328E-05

-2.757E-05

S12

-6.890E-02

5.663E-03

-4.233E-04

-2.404E-04

4.470E-05

3.812E-05

-5.243E-06

wherein x is the distance rise from the vertex of the aspheric surface when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, where c is 1/r (i.e., paraxial curvature c is the inverse of radius of curvature r in table 3 above); k is the conic constant (given in table 3 above); ai is a correction coefficient of the i-n th order of the aspherical surface, and the coefficients of the high-order terms a4, a6, A8, a10, a12, a14, and a16 of the respective lens surfaces S1 through S12 are shown in table 4.

Given the design data of the infrared lens 100 according to the second embodiment of the present application, the effective focal length EFL is 1.168mm, the maximum field angle FOV is 124.862 degrees, the total optical length TTL is 5.961mm, and the F-stop F value f.no is 2.112.

In one embodiment provided herein, (tanHFOV × TTL)/(SAG21+ SAG22) ═ 28.271.

In one embodiment provided herein, D26/TTL is 0.565.

In one example provided herein, (DT11-DT12)/(SAG12-SAG11) ═ 103.458.

In one embodiment provided herein, f456/(T45+ T56) is 26.564.

In one example provided herein, (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) is 7.184.

In one embodiment provided herein, (f6-f1)/f — 3.410.

In one example provided herein, (DT52+ DT61)/(SAG52-SAG61) ═ 45.441.

In one embodiment provided herein, | R41+ R42|/f4 ═ 0.751.

Fig. 7-10 illustrate the optical performance of an ir lens 100 designed in accordance with the second embodiment of this lens combination.

In the second embodiment, the infrared lens satisfies the requirements of large wide angle, high imaging quality and miniaturization.

EXAMPLE III

The infrared lens 100 of an embodiment of the present application, in order from an object side to an image side, includes: a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106, as shown in fig. 11.

In light of the above relations, table 5 shows the effective focal length EFL, the maximum field angle FOV, the total optical length TTL, the F-number f.no, the surface type, the curvature radius, the thickness, the refractive index of the material, and the conic coefficient of the infrared lens 100 in the third embodiment, where the curvature radius and the thickness are both in millimeters (mm), as shown in table 5:

TABLE 5

Table 6 shows aspheric coefficients of the infrared lens 100 according to the third embodiment of the present application, as shown in table 6:

TABLE 6

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

3.893E-03

1.204E-04

2.717E-05

1.059E-06

-3.645E-07

-2.586E-08

6.779E-09

S2

-2.097E-02

-5.056E-02

-9.055E-04

-1.267E-03

3.938E-05

1.730E-03

-4.351E-04

S3

-1.003E-01

-5.249E-02

9.689E-02

3.080E-02

-3.532E-02

9.122E-03

-5.847E-03

S4

3.046E-01

-2.838E-01

2.343E+00

-1.953E+00

-2.886E+00

-2.151E+00

3.594E+01

S5

5.477E-02

2.132E-01

3.996E-01

-5.108E+00

-1.094E+01

1.004E+02

-1.438E+02

S6

-2.797E-01

-2.475E-02

3.847E-01

-3.036E+00

2.227E+00

1.274E+01

-1.696E+01

S7

-6.037E-01

9.426E-01

-3.847E+00

9.916E-01

5.919E+00

-8.573E+00

-7.472E+00

S8

4.330E-02

1.279E-01

-6.438E-02

-1.513E-01

1.727E-01

2.162E-01

-1.453E-01

S9

-3.705E-02

8.560E-03

1.962E-03

-2.035E-03

-5.297E-04

4.295E-04

-6.568E-05

S10

-8.886E-02

7.239E-03

3.564E-03

7.183E-04

-3.342E-04

-2.035E-04

3.680E-05

S11

-9.441E-02

-1.168E-02

7.920E-04

1.086E-03

3.616E-04

4.840E-05

-3.597E-05

S12

-6.866E-02

6.732E-03

-5.032E-04

-3.429E-04

1.205E-05

3.479E-05

-2.425E-06

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/r (i.e., paraxial curvature c is the inverse of radius of curvature r in table 5 above); k is the conic constant (given in table 5 above); ai is a correction coefficient of the i-n th order of the aspherical surface, and the coefficients of the high-order terms a4, a6, A8, a10, a12, a14, and a16 of the respective lens surfaces S1 through S12 are shown in table 6.

Given the design data of the infrared lens 100 according to the third embodiment of the present application, the effective focal length EFL is 1.171mm, the maximum field angle FOV is 124.866 degrees, the total optical length TTL is 5.962mm, and the F-number f.no is 2.111.

In one embodiment provided herein, (tanHFOV × TTL)/(SAG21+ SAG22) ═ 29.772.

In one embodiment provided herein, D26/TTL is 0.551.

In one example provided herein, (DT11-DT12)/(SAG12-SAG11) ═ 86.861.

In one embodiment provided herein, f456/(T45+ T56) is 26.858.

In one example provided herein, (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) is 5.984.

In one embodiment provided herein, (f6-f1)/f — 3.385.

In one example provided herein, (DT52+ DT61)/(SAG52-SAG61) ═ 50.330.

In one embodiment provided herein, | R41+ R42|/f4 | -0.745.

Fig. 12 to 15 illustrate the optical performance of the infrared lens 100 designed in the third embodiment of the lens combination.

In the third embodiment, the infrared lens meets the requirements of large wide angle, high imaging quality and miniaturization.

Example four

The infrared lens 100 of an embodiment of the present application, in order from an object side to an image side, includes: a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106, as shown in fig. 16.

In light of the above relations, table 7 shows the effective focal length EFL, the maximum field angle FOV, the total optical length TTL, the F-number f.no, the surface type, the curvature radius, the thickness, the refractive index of the material, and the conic coefficient of the infrared lens 100 in the fourth embodiment, where the curvature radius and the thickness are both in millimeters (mm), as shown in table 7:

TABLE 7

Table 8 shows aspheric coefficients of the infrared lens 100 according to the fourth embodiment of the present application, as shown in table 8:

TABLE 8

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

4.026E-03

1.298E-04

2.789E-05

1.141E-06

-3.476E-07

-2.425E-08

6.131E-09

S2

-1.692E-02

-4.966E-02

-1.287E-03

-1.530E-03

-8.006E-05

1.701E-03

-4.169E-04

S3

-1.042E-01

-5.294E-02

9.833E-02

2.568E-02

-3.782E-02

1.215E-02

-5.725E-03

S4

3.103E-01

-2.394E-01

2.323E+00

-2.271E+00

-2.567E+00

9.320E-01

3.459E+01

S5

5.661E-02

2.120E-01

4.066E-01

-5.084E+00

-1.085E+01

1.009E+02

-1.417E+02

S6

-2.995E-01

-9.425E-02

3.814E-01

-3.001E+00

2.254E+00

1.283E+01

-1.643E+01

S7

-5.957E-01

9.039E-01

-3.813E+00

1.071E+00

5.759E+00

-8.649E+00

-5.278E+00

S8

4.813E-02

1.404E-01

-6.392E-02

-1.536E-01

1.699E-01

2.129E-01

-1.484E-01

S9

-3.507E-02

6.966E-03

1.021E-03

-2.325E-03

-5.487E-04

4.677E-04

-3.397E-05

S10

-9.332E-02

9.408E-03

4.062E-03

5.781E-04

-4.716E-04

-2.289E-04

5.806E-05

S11

-9.707E-02

-1.146E-02

1.052E-03

1.188E-03

3.998E-04

5.171E-05

-4.316E-05

S12

-6.580E-02

6.330E-03

-6.765E-04

-3.774E-04

6.775E-06

3.506E-05

-1.643E-06

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/r (i.e., paraxial curvature c is the inverse of radius of curvature r in table 7 above); k is the conic constant (given in table 7 above); ai is a correction coefficient of the i-n th order of the aspherical surface, and the coefficients of the high-order terms a4, a6, A8, a10, a12, a14, and a16 of the respective lens surfaces S1 through S12 are shown in table 8.

Given the design data of the infrared lens 100 according to the fourth embodiment of the present application, the effective focal length EFL is 1.172mm, the maximum field angle FOV is 124.866 degrees, the total optical length TTL is 5.972mm, and the F-stop f.no is 2.108.

In one embodiment provided herein, (tanHFOV × TTL)/(SAG21+ SAG22) ═ 31.807.

In one embodiment provided herein, D26/TTL is 0.554.

In one example provided herein, (DT11-DT12)/(SAG12-SAG11) ═ 51.260.

In one embodiment provided herein, f456/(T45+ T56) is 28.525.

In one example provided herein, (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) is 4.948.

In one embodiment provided herein, (f6-f1)/f ═ 3.324.

In one example provided herein, (DT52+ DT61)/(SAG52-SAG61) ═ 56.002.

In one embodiment provided herein, | R41+ R42|/f4 ═ 0.719.

Fig. 17 to 20 illustrate the optical performance of the infrared lens 100 designed in the four lens combinations of the embodiment.

In the fourth embodiment, the infrared lens satisfies the requirements of large wide angle, high imaging quality and miniaturization.

EXAMPLE five

The infrared lens 100 of an embodiment of the present application, in order from an object side to an image side, includes: a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106, as shown in fig. 21.

In light of the above relations, table 9 shows the effective focal length EFL, the maximum field angle FOV, the total optical length TTL, the F-number f.no, the surface type, the curvature radius, the thickness, the refractive index of the material, and the conic coefficient of the infrared lens 100 in the fifth embodiment, where the curvature radius and the thickness are both in millimeters (mm), as shown in table 9:

TABLE 9

Table 10 shows aspheric coefficients of the infrared lens 100 according to the fifth embodiment of the present application, as shown in table 10:

watch 10

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

5.457E-03

2.865E-04

2.785E-07

1.048E-06

2.345E-07

3.592E-08

-4.106E-09

S2

-2.126E-02

-4.152E-02

-3.177E-03

-1.606E-03

-5.695E-04

1.369E-03

-2.797E-04

S3

-1.367E-01

-7.637E-02

1.912E-01

-7.407E-02

-6.461E-02

7.282E-02

-2.006E-02

S4

3.560E-01

-5.588E-01

2.154E+00

5.297E+00

-1.446E+01

-5.044E+01

1.522E+02

S5

8.641E-02

9.474E-02

7.693E-01

-4.076E+00

-1.867E+01

1.327E+02

-1.892E+02

S6

-3.036E-01

-2.444E-01

4.562E-01

-2.368E+00

7.431E-01

6.576E+00

-3.854E+00

S7

-6.110E-01

1.379E+00

-5.071E+00

4.975E+00

4.232E+00

-2.761E+01

2.552E+01

S8

-1.005E-02

3.767E-01

-2.666E-01

-2.915E-01

2.803E-01

3.024E-01

-2.264E-01

S9

-1.429E-02

-3.436E-03

-2.330E-04

5.283E-04

-2.470E-04

-3.638E-04

1.775E-05

S10

-8.947E-02

1.192E-02

8.525E-03

1.279E-03

-1.129E-03

-4.486E-04

1.389E-04

S11

-9.708E-02

1.335E-03

2.649E-03

-7.718E-04

1.829E-04

1.678E-04

-3.938E-05

S12

-6.142E-02

1.280E-02

-1.281E-03

-5.640E-04

-4.408E-05

2.597E-05

2.244E-06

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/r (i.e., paraxial curvature c is the inverse of radius of curvature r in table 9 above); k is the conic constant (given in table 9 above); ai is a correction coefficient of the i-n th order of the aspherical surface, and the coefficients of the high-order terms a4, a6, A8, a10, a12, a14, and a16 of the respective lens surfaces S1 through S12 are shown in table 10.

Given the design data of the infrared lens 100 according to the fifth embodiment of the present application, the effective focal length EFL is 1.171mm, the maximum field angle FOV is 124.878 degrees, the total optical length TTL is 5.972mm, and the F-stop f.no is 2.106.

In one embodiment provided herein, (tanHFOV × TTL)/(SAG21+ SAG22) ═ 39.742.

In one embodiment provided herein, D26/TTL is 0.567.

In one example provided herein, (DT11-DT12)/(SAG12-SAG11) ═ 77.623.

In one embodiment provided herein, f456/(T45+ T56) is 24.953.

In one example provided herein, (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) is 4.845.

In one embodiment provided herein, (f6-f1)/f 3.446.

In one example provided herein, (DT52+ DT61)/(SAG52-SAG61) ═ 37.800.

In one embodiment provided herein, | R41+ R42|/f4 ═ 0.766.

Fig. 22 to 25 illustrate the optical performance of the infrared lens 100 designed in such a lens combination as described in example five.

In the fifth embodiment, the infrared lens satisfies the requirements of large wide angle, high imaging quality, and miniaturization.

EXAMPLE six

The infrared lens 100 of an embodiment of the present application, in order from an object side to an image side, includes: a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106, as shown in fig. 26.

For convenience of description, in the following embodiments, STO denotes a surface of a stop, S1 denotes an object-side surface of the first lens 101, S2 denotes an image-side surface of the first lens 101, S3 denotes an object-side surface of the second lens 102, S4 denotes an image-side surface of the second lens 102, S5 denotes an object-side surface of the third lens 103, S6 denotes an image-side surface of the third lens 103, S7 denotes an object-side surface of the fourth lens 104, S8 denotes an image-side surface of the fourth lens 104, S9 denotes an object-side surface of the fifth lens 105, S10 denotes an image-side surface of the fifth lens 105, S11 denotes an object-side surface of the sixth lens 106, S12 denotes an image-side surface of the sixth lens 106, S13 denotes an object-side surface of a filter, S14 denotes an image-side surface of the filter, and S15 denotes an imaging surface. The total optical length of the ir lens 100 is denoted by TTL, the maximum image height of the ir lens 100 is denoted by ImgH, and the effective focal length of the ir lens 100 is denoted by EFL. The ith order aspheric coefficients are represented by α i, i is 4, 6, 8, 10, 12, 14, 16, and the cone coefficients are represented by K.

In light of the above relations, table 11 shows the effective focal length EFL, the maximum field angle FOV, the total optical length TTL, the F-number f.no, the surface type, the curvature radius, the thickness, the refractive index of the material, and the conic coefficient of the infrared lens 100 in the sixth embodiment, where the curvature radius and the thickness are both in millimeters (mm), as shown in table 11:

TABLE 11

Table 12 shows aspheric coefficients of the infrared lens 100 according to the sixth embodiment of the present application, as shown in table 12:

TABLE 12

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/r (i.e., paraxial curvature c is the inverse of radius of curvature r in table 11 above); k is the conic constant (given in table 11 above); ai is a correction coefficient of the i-n th order of the aspherical surface, and the coefficients of high-order terms a4, a6, A8, a10, a12, a14, and a16 of the respective lens surfaces S1 to S12 are shown in table 12.

Given the design data of the infrared lens 100 according to the sixth embodiment of the present application, the effective focal length EFL is 1.169mm, the maximum field angle FOV is 124.874 degrees, the total optical length TTL is 5.977mm, and the F-stop F value f.no is 2.106.

In one embodiment provided herein, (tanHFOV × TTL)/(SAG21+ SAG22) ═ 39.048.

In one embodiment provided herein, D26/TTL is 0.567.

In one example provided herein, (DT11-DT12)/(SAG12-SAG11) ═ 56.279.

In one embodiment provided herein, f456/(T45+ T56) is 24.616.

In one example provided herein, (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) is 4.767.

In one embodiment provided herein, (f6-f1)/f 3.451.

In one example provided herein, (DT52+ DT61)/(SAG52-SAG61) ═ 44.012.

In one embodiment provided herein, | R41+ R42|/f4 ═ 0.768.

Fig. 27 to 30 illustrate the optical performance of the infrared lens 100 designed in the lens combination of the sixth embodiment.

In the sixth embodiment, the infrared lens satisfies the requirements of large wide angle, high imaging quality, and miniaturization.

In addition, examples one to six correspond to the (tanHFOV × TTL)/(SAG21+ SAG22) ratio, D26/TTL ratio, (DT11-DT12)/(SAG12-SAG11) ratio, f456/(T45+ T56) ratio, (f234+ f56)/(CT2+ CT3+ CT4+ CT5+ CT6) ratio, (f6-f1)/f ratio, (DT52+ DT61)/(SAG52-SAG61) ratio, and | R41+ R42|/f4 ratio, as shown in table 13:

watch 13

In at least one or more of the above embodiments, the image-side surface S10 of the fifth lens 105 includes at least three inflection points Y, which is beneficial to optimizing aberrations and improving the imaging quality of the infrared lens.

The present invention further provides an infrared lens module, which includes the infrared lens 100 in any of the above embodiments, and may further include an image sensor, an analog-to-digital converter, an image processor, a memory, and the like, so as to implement a camera function of the infrared lens.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. The invention is not to be limited to the specific embodiments disclosed herein, but to other embodiments falling within the scope of the claims of the present application.

Claims

1. An infrared lens, comprising, in order from an object side to an image side along an optical axis:

the infrared lens meets the following conditional expression:

27.782<(tanHFOV×TTL)/(SAG21+SAG22)<39.742；

wherein, HFOV is half of the maximum field angle of the infrared lens, TTL is the distance on the optical axis from the object-side surface of the first lens to the imaging surface of the infrared lens, and SAG21 is the distance on the optical axis from the intersection of the object-side surface of the second lens and the optical axis to the effective radius vertex of the object-side surface of the second lens; SAG22 is the distance on the optical axis from the intersection point of the image side surface of the second lens and the optical axis to the effective radius vertex of the image side surface of the second lens.

2. The infrared lens as claimed in claim 1, wherein the infrared lens satisfies the following conditional expression:

0.551<D26/TTL<0.567；

wherein D26 is the distance on the optical axis from the object-side surface of the second lens element to the image-side surface of the sixth lens element; TTL is the distance on the optical axis from the object side surface of the first lens to the imaging surface of the infrared lens.

3. The infrared lens as claimed in claim 1 or 2, characterized in that the infrared lens satisfies the following conditional expression:

51.260<(DT11-DT12)/(SAG12-SAG11)<134.234；

wherein DT11 is the maximum effective radius of the object side surface of the first lens; DT12 is the maximum effective radius of the image side surface of the first lens; SAG11 is the distance on the optical axis from the intersection point of the object side surface of the first lens and the optical axis to the effective radius vertex of the object side surface of the first lens; SAG12 is the distance on the optical axis from the intersection point of the image side surface of the first lens and the optical axis to the effective radius vertex of the image side surface of the first lens.

4. The infrared lens as claimed in claim 3, wherein the infrared lens satisfies the following conditional expression:

24.616<f456/(T45+T56)<28.525；

wherein f456 is a combined focal length of the fourth lens, the fifth lens and the sixth lens, T45 is a distance between the fourth lens and the fifth lens on the optical axis, and T56 is a distance between the fifth lens and the sixth lens on the optical axis.

5. The infrared lens as claimed in claim 4, wherein the infrared lens satisfies the following conditional expression:

4.767<(f234+f56)/(CT2+CT3+CT4+CT5+CT6)<8.543；

wherein, f234 is the combined focal length of the second lens, the third lens and the fourth lens, f56 is the combined focal length of the fifth lens and the sixth lens, CT2 is the central thickness of the second lens on the optical axis, CT3 is the central thickness of the third lens on the optical axis, CT4 is the central thickness of the fourth lens on the optical axis, CT5 is the central thickness of the fifth lens on the optical axis, and CT6 is the central thickness of the sixth lens on the optical axis.

6. The infrared lens as claimed in claim 4 or 5, wherein the infrared lens satisfies the following conditional expression:

3.324<(f6-f1)/f<3.451；

wherein f1 is an effective focal length of the first lens, f6 is an effective focal length of the sixth lens, and f is a total effective focal length of the infrared lens.

7. The infrared lens as claimed in claim 6, wherein the infrared lens satisfies the following conditional expression:

37.800<(DT52+DT61)/(SAG52-SAG61)<56.002；

wherein DT52 is the maximum effective radius of the image-side surface of the fifth lens, DT61 is the maximum effective radius of the object-side surface of the sixth lens, SAG52 is the distance on the optical axis from the intersection point of the image-side surface of the fifth lens and the optical axis to the vertex of the effective radius of the image-side surface of the fifth lens, and SAG61 is the distance on the optical axis from the intersection point of the object-side surface of the sixth lens and the optical axis to the vertex of the effective radius of the object-side surface of the sixth lens.

8. An infrared lens according to any one of claims 1 to 7, characterized in that the infrared lens satisfies the following conditional expression:

0.719<|R41+R42|/f4<0.768；

wherein R41 is the curvature radius of the object-side surface of the fourth lens element, R42 is the curvature radius of the image-side surface of the fourth lens element, and f4 is the effective focal length of the fourth lens element.

9. The infrared lens as set forth in claim 8, characterized in that:

the image side surface of the fifth lens comprises at least three points of inflection.

10. An infrared lens module comprising the infrared lens as set forth in any one of claims 1 to 9.