阅读说明：本技术 一种镜头 (Lens ) 是由 邢圆圆 刘凯 丁洪兴 郭安峰 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种镜头,由物侧至像侧依次排列第一透镜组、第二透镜组、第三透镜组、孔径光阑、第四透镜组、第五透镜组、滤光片和像面构成；透镜组满足以下条件：f2为第二透镜组的焦距,f4为第四透镜组的焦距,f-(w)为镜头在短焦状态下的焦距,f-(T)为镜头在长焦状态下的焦距,FOV-(w)为镜头在短焦状态下的视场角,FOV-(T)为镜头在长焦状态下的视场角。实现大靶面、大光圈、低成本的高分辨率镜头。(The invention discloses a lens, which consists of a first lens group, a second lens group, a third lens group, an aperture diaphragm, a fourth lens group, a fifth lens group, an optical filter and an image surface which are sequentially arranged from an object side to an image side; the lens group satisfies the following conditions: f2 is the focal length of the second lens group, f4 is the focal length of the fourth lens group, f w Is the focal length of the lens in the short focus state, f T For the focal length, FOV, of the lens in tele state w For the field of view, FOV, of the lens in short focus T The angle of view of the lens in the telephoto state. The high-resolution lens with large target surface, large aperture and low cost is realized.)

1. A lens is characterized in that the lens is composed of a first lens group, a second lens group, a third lens group, an aperture diaphragm, a fourth lens group, a fifth lens group, an optical filter and an image surface which are sequentially arranged from an object side to an image side;

the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis;

the lens group satisfies the following conditions:

wherein，f₂Is the focal length of the second lens group, f₄Is the focal length of the fourth lens group, f_wIs the focal length of the lens in the short focus state, f_TFor the focal length, FOV, of the lens in tele state_wFor the field angle, FOV, of the lens in short focus_TThe field angle of the lens in a long-focus state is defined;

the first lens group is composed of a first negative focal power lens;

the second lens group consists of a second negative power lens and a third negative power lens which are arranged in sequence from the object side to the image side;

the third lens group consists of a first positive focal power lens, a second positive focal power lens, a third positive focal power lens, a fourth negative focal power lens and a fourth positive focal power lens which are arranged in sequence from the object side to the image side;

the fourth lens group is composed of a fifth positive power lens and a sixth positive power lens which are arranged in sequence from the object side to the image side;

the fifth lens group is composed of a seventh positive focal power lens, a fifth negative focal power lens and a sixth negative focal power lens which are arranged in sequence from the object side to the image side.

2. The lens barrel as claimed in claim 1, wherein the first negative power lens is a biconcave lens;

the second negative focal power lens is a biconcave lens;

the third negative focal power lens is a biconcave lens;

the first positive focal power lens is a meniscus lens, and one surface of the first positive focal power lens facing the image side is a convex surface;

the second positive focal power lens is a biconvex lens;

the third positive focal power lens is a meniscus lens, and one surface of the third positive focal power lens facing the object side is a convex surface;

the fourth negative power lens is a meniscus lens, and one surface of the fourth negative power lens facing the object side is a convex surface;

the fourth positive focal power lens is a meniscus lens, and one surface of the fourth positive focal power lens facing the object side is a convex surface;

the fifth positive focal power lens is a biconvex lens;

the sixth positive focal power lens is a biconvex lens;

the seventh positive focal power lens is a biconvex lens;

the fifth negative focal power lens is a meniscus lens, and one surface of the fifth negative focal power lens facing the image side is a convex surface;

the sixth negative-power lens is a meniscus lens, and one surface of the sixth negative-power lens facing the image side is a convex surface.

3. The lens barrel according to claim 1, wherein the fourth negative power lens and the fourth positive power lens constitute a cemented lens group;

and the seventh positive focal power lens and the fifth negative focal power lens form a cemented lens group.

4. The lens barrel as claimed in claim 1, wherein a center radius of curvature R2 of an image side surface of the first negative power lens and a center radius of curvature R3 of an object side surface of the second negative power lens satisfy:

5. the lens barrel according to claim 1, wherein a distance BFL from an image-side surface of the sixth negative power lens to an image surface and a distance TL from an object-side surface of the first negative power lens to an image-side surface of the sixth negative power lens satisfy: BFL/TL is less than or equal to 0.3.

6. The lens barrel according to claim 1, wherein f11 of the focal length of the first negative power lens, f22 of the focal length of the third negative power lens, and f35 of the focal length of the fourth positive power lens satisfy: f12 is less than or equal to-15; f22 is less than or equal to-53; f35 is less than or equal to 45.

7. The lens barrel according to claim 1, wherein an abbe number Vd21 of a glass material of the second negative power lens, an abbe number Vd33 of a glass material of the third positive power lens, and an abbe number Vd51 of a glass material of the seventh positive power lens satisfy: vd21 is less than or equal to 40; vd33 is less than or equal to 35; vd51 is less than or equal to 92.

8. The lens barrel according to claim 1, wherein a refractive index Nd32 of a glass material of the second positive power lens, a refractive index Nd34 of a glass material of the fourth negative power lens, a refractive index Nd41 of a glass material of the fifth positive power lens, and a refractive index Nd52 of a glass material of the fifth negative power lens satisfy: nd32 is less than or equal to 1.85; nd34 is less than or equal to 1.95; nd41 is less than or equal to 1.75; nd52 is more than or equal to 1.85.

Technical Field

The invention relates to the technical field of optical imaging, in particular to a lens.

Background

Owing to the rapid development of the security monitoring field in recent years, the optical lens is increasingly applied to the security field, and particularly in the fields of intelligent buildings, intelligent transportation and the like, the pixel requirement of the optical imaging lens is higher and higher. More and more enterprises are beginning to invest more research in ultra high definition, and are expecting to develop products with higher pixels and smaller sizes.

In the field of intelligent transportation, the monitoring range is relatively fixed, generally for crossing and lane monitoring, the fixed focus lens with the focal length of 12mm and the fixed focus lens with the focal length of 16mm are used more, and when different monitoring ranges are to be realized, a zoom lens with the focal length of 12-25mm or two lenses with the focal lengths of 12mm and 16mm are generally required to be used or switched, so that the use is difficult, and the cost is higher. However, the following problems still exist in the existing optical imaging lens: 1. there is no zoom lens of this size of 1 inch 12-16mm for the moment on the market. 2. The existing 12-25mm fixed-focus lens on the market has more lenses and higher cost. 3. The lens resolution is not high, and the imaging quality is general. 4. The lens target surface is small and cannot meet the use of a sensor with a target surface of 1 inch or more. 5. Most lenses do not have infrared confocal function.

Therefore, a 12-16mm optical zoom lens with high resolving power and the characteristics of large target surface, miniaturization, low cost and the like is urgently needed in the market at present.

Disclosure of Invention

The embodiment of the invention provides a lens, which is used for providing a high-resolution lens with a large target surface, a large aperture and low cost.

The embodiment of the invention provides a lens, which is composed of a first lens group, a second lens group, a third lens group, an aperture diaphragm, a fourth lens group, a fifth lens group, an optical filter and an image plane which are sequentially arranged from an object side to an image side;

the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis;

the lens group satisfies the following conditions:

wherein f2 is a focal length of the second lens group, f4 is a focal length of the fourth lens group, f_wIs the focal length of the lens in the short focus state, f_TFor the focal length, FOV, of the lens in tele state_wFor the field angle, FOV, of the lens in short focus_TThe field angle of the lens in a long-focus state is defined;

the first lens group is composed of a first negative focal power lens;

the second lens group consists of a second negative power lens and a third negative power lens which are arranged in sequence from the object side to the image side;

the third lens group consists of a first positive focal power lens, a second positive focal power lens, a third positive focal power lens, a fourth negative focal power lens and a fourth positive focal power lens which are arranged in sequence from the object side to the image side;

the fourth lens group is composed of a fifth positive power lens and a sixth positive power lens which are arranged in sequence from the object side to the image side;

the fifth lens group is composed of a seventh positive focal power lens, a fifth negative focal power lens and a sixth negative focal power lens which are arranged in sequence from the object side to the image side.

Further, the first negative power lens is a biconcave lens;

the second negative focal power lens is a biconcave lens;

the third negative focal power lens is a biconcave lens;

the first positive focal power lens is a meniscus lens, and one surface of the first positive focal power lens facing the image side is a convex surface;

the second positive focal power lens is a biconvex lens;

the third positive focal power lens is a meniscus lens, and one surface of the third positive focal power lens facing the object side is a convex surface;

the fourth negative power lens is a meniscus lens, and one surface of the fourth negative power lens facing the object side is a convex surface;

the fourth positive focal power lens is a meniscus lens, and one surface of the fourth positive focal power lens facing the object side is a convex surface;

the fifth positive focal power lens is a biconvex lens;

the sixth positive focal power lens is a biconvex lens;

the seventh positive focal power lens is a biconvex lens;

the fifth negative focal power lens is a meniscus lens, and one surface of the fifth negative focal power lens facing the image side is a convex surface;

the sixth negative-power lens is a meniscus lens, and one surface of the sixth negative-power lens facing the image side is a convex surface.

Further, the fourth negative power lens and the fourth positive power lens constitute a cemented lens group;

and the seventh positive focal power lens and the fifth negative focal power lens form a cemented lens group.

Further, the central curvature radius R2 of the image side surface of the first negative power lens and the central curvature radius R3 of the object side surface of the second negative power lens satisfy:

further, a distance BFL from the image side surface of the sixth negative power lens to the image surface and a distance TL from the object surface side of the first negative power lens to the image side surface of the sixth negative power lens satisfy: BFL/TL is less than or equal to 0.3.

Further, f11 of the focal length of the first negative power lens, f22 of the focal length of the third negative power lens, and f35 of the focal length of the fourth positive power lens satisfy: f12 is less than or equal to-15; f22 is less than or equal to-53; f35 is less than or equal to 45.

Further, the abbe number Vd21 of the glass material of the second negative power lens, the abbe number Vd33 of the glass material of the third positive power lens, and the abbe number Vd51 of the glass material of the seventh positive power lens satisfy: vd21 is less than or equal to 40; vd33 is less than or equal to 35; vd51 is less than or equal to 92.

Further, the refractive index Nd32 of the glass material of the second positive power lens, the refractive index Nd34 of the glass material of the fourth negative power lens, the refractive index Nd41 of the glass material of the fifth positive power lens, and the refractive index Nd52 of the glass material of the fifth negative power lens satisfy: nd32 is less than or equal to 1.85; nd34 is less than or equal to 1.95; nd41 is less than or equal to 1.75; nd52 is more than or equal to 1.85.

The embodiment of the invention provides a lens, which is composed of a first lens group, a second lens group, a third lens group, an aperture diaphragm, a fourth lens group, a fifth lens group, an optical filter and an image plane which are sequentially arranged from an object side to an image side; the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis; the lens group satisfies the following conditions: wherein f is₂Is the focal length of the second lens group, f₄Is the focal length of the fourth lens group, f_wIs the focal length of the lens in the short focus state, f_TFor the focal length, FOV, of the lens in tele state_wFor the field angle, FOV, of the lens in short focus_TThe angle of view of the lens in the telephoto state. Since in the embodiment of the present invention, five lens groups are arranged in the lens in order from the object side to the image side in a specific order, the five lens groups include 13 lenses of specific power, the positions of the first lens group, the third lens group and the fifth lens group are fixed, the second lens group and the fourth lens group can move along the optical axis to realize lens zooming, and the lens groups in the lens satisfy: the high-resolution lens with the large target surface, the large aperture and the low cost is realized.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic view of a lens in a short focus state according to an embodiment of the present invention;

fig. 2 is a schematic view of a lens in a telephoto state according to an embodiment of the present invention;

fig. 3 is a graph of an optical transfer function (MTF) in a normal temperature state of a visible light band in a short focus state of the lens according to the embodiment of the present invention;

fig. 4 is a field curvature and distortion diagram of the lens in the short focus state in the visible light band according to the embodiment of the present invention;

fig. 5 is a transverse light fan diagram of the lens in the short focus state in the visible light band according to the embodiment of the present invention;

fig. 6 is a dot-column diagram of a visible light band in a short-focus state of the lens according to the embodiment of the present invention;

fig. 7 is a graph of an optical transfer function (MTF) in a normal temperature state of a visible light band in a telephoto state according to an embodiment of the present invention;

FIG. 8 is a diagram illustrating curvature of field and distortion in the visible light band for a long focus lens according to an embodiment of the present invention;

FIG. 9 is a diagram of the lateral light fan in the visible band in the telephoto state of the lens according to the embodiment of the present invention;

fig. 10 is a dot-column diagram of the lens in the telephoto state in the visible light band according to the embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the attached drawings, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 1 is a schematic view of a lens barrel according to embodiment 1, which includes, in order from an object side to an image side, a first lens group G1, a second lens group G2, a third lens group G3, an aperture stop P, a fourth lens group G4, a fifth lens group G5, a filter M, and an image plane N;

the positions of the first lens group G1, the third lens group G3 and the fifth lens group G5 are fixed, and the second lens group G2 and the fourth lens group G4 can move along the optical axis;

the lens group satisfies the following conditions:

wherein f2 is a focal length of the second lens group, f4 is a focal length of the fourth lens group, f_wIs the focal length of the lens in the short focus state, f_TFor the focal length, FOV, of the lens in tele state_wFor the field angle, FOV, of the lens in short focus_TThe field angle of the lens in a long-focus state is defined;

the first lens group G1 is constituted by a first negative power lens L11;

the second lens group G2 is composed of a second negative power lens L21 and a third negative power lens L2 which are arranged in order from the object side to the image side;

the third lens group G3 is composed of a first positive power lens L31, a second positive power lens L32, a third positive power lens L33, a fourth negative power lens L34 and a fourth positive power lens L35 which are arranged in order from the object side to the image side;

the fourth lens group G4 is composed of a fifth positive power lens L41 and a sixth positive power lens 42 arranged in order from the object side to the image side;

the fifth lens group G5 is composed of a seventh positive power lens L51, a fifth negative power lens L52, and a sixth negative power lens L53, which are arranged in this order from the object side to the image side.

The lens barrel can realize zooming by changing the positions of lens groups, wherein the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis to realize zooming. That is, the second lens group can be moved in a position between the first lens group and the third lens group. The second lens group may be close to the first lens group, far from the third lens group; it may be away from the first lens group and close to the third lens group. The fourth lens group may be moved in a position between the aperture stop and the fifth lens group. The fourth lens group may be close to the aperture stop, distant from the fifth lens group; or may be located away from the aperture stop and close to the fifth lens group. The second lens group moves in the optical axis direction to perform zooming, and is called a zoom group or a magnification-varying group. In addition, compensation is performed by moving the fourth lens group in the direction of the optical axis so that the image point variation caused by the second lens group at the image plane is zero, thereby realizing zooming without moving the image plane, which is called a compensation group. In addition, when the object of interest moves, the image is focused sharply by finely adjusting the fourth lens group. In general, in the lens system, the fourth lens group functions as a compensation group and a focusing group.

The aperture size of the aperture diaphragm determines the aperture value of the system and the depth of field during shooting, the aperture size can be fixed, or the aperture diaphragm with adjustable aperture can be placed according to the requirement to realize the adjustment of the clear aperture, namely the purpose of changing the aperture value of the system and the depth of field is achieved.

Since in the embodiment of the present invention, five lens groups are arranged in the lens in order from the object side to the image side in a specific order, the five lens groups include 13 lenses of specific power, the positions of the first lens group, the third lens group and the fifth lens group are fixed, the second lens group and the fourth lens group can move along the optical axis to realize lens zooming, and the lens groups in the lens satisfy: the high-resolution lens with the large target surface, the large aperture and the low cost is realized.

In order to further improve the imaging quality of the lens, in the embodiment of the invention, the first negative power lens is a biconcave lens;

the second negative focal power lens is a biconcave lens;

the third negative focal power lens is a biconcave lens;

the first positive focal power lens is a meniscus lens, and one surface of the first positive focal power lens facing the image side is a convex surface;

the second positive focal power lens is a biconvex lens;

the third positive focal power lens is a meniscus lens, and one surface of the third positive focal power lens facing the object side is a convex surface;

the fourth negative power lens is a meniscus lens, and one surface of the fourth negative power lens facing the object side is a convex surface;

the fourth positive focal power lens is a meniscus lens, and one surface of the fourth positive focal power lens facing the object side is a convex surface;

the fifth positive focal power lens is a biconvex lens;

the sixth positive focal power lens is a biconvex lens;

the seventh positive focal power lens is a biconvex lens;

the fifth negative focal power lens is a meniscus lens, and one surface of the fifth negative focal power lens facing the image side is a convex surface;

the sixth negative-power lens is a meniscus lens, and one surface of the sixth negative-power lens facing the image side is a convex surface.

In order to further enable the system to be compact, in the embodiment of the present invention, the fourth negative power lens and the fourth positive power lens constitute a cemented lens group;

and the seventh positive focal power lens and the fifth negative focal power lens form a cemented lens group.

In order to further improve the imaging quality of the lens and improve the processing performance of the lens, in the embodiment of the invention, the central curvature radius R2 of the image side surface of the first negative power lens and the central curvature radius R3 of the object side surface of the second negative power lens satisfy the following conditions:

in order to further enable the system to be compact, in the embodiment of the present invention, a distance BFL from the image-side surface of the sixth negative power lens to the image plane and a distance TL from the object-side surface of the first negative power lens to the image-side surface of the sixth negative power lens satisfy: BFL/TL is less than or equal to 0.3.

In order to further improve the imaging quality of the lens, in the embodiment of the present invention, f11 of the focal length of the first negative power lens, f22 of the focal length of the third negative power lens, and f35 of the focal length of the fourth positive power lens satisfy: f12 is less than or equal to-15; f22 is less than or equal to-53; f35 is less than or equal to 45.

In the embodiment of the present invention, in order to enable a lens to form an image clearly in a wide temperature range, in the embodiment of the present invention, the abbe number Vd21 of the glass material of the second negative power lens, the abbe number Vd33 of the glass material of the third positive power lens, and the abbe number Vd51 of the glass material of the seventh positive power lens satisfy: vd21 is less than or equal to 40; vd33 is less than or equal to 35; vd51 is less than or equal to 92. In addition, the following are satisfied: vd21 is less than or equal to 40; vd33 is less than or equal to 35; vd51 ≦ 92 can also reduce the chromatic aberration of the image, thereby improving the imaging quality.

In order to improve the imaging quality of the lens and reduce the total length of the lens, in the embodiment of the invention, the refractive index Nd32 of the glass material of the second positive power lens, the refractive index Nd34 of the glass material of the fourth negative power lens, the refractive index Nd41 of the glass material of the fifth positive power lens and the refractive index Nd52 of the glass material of the fifth negative power lens satisfy: nd32 is less than or equal to 1.85; nd34 is less than or equal to 1.95; nd41 is less than or equal to 1.75; nd52 is more than or equal to 1.85. And, satisfies: nd32 is less than or equal to 1.85; nd34 is less than or equal to 1.95; nd41 is less than or equal to 1.75; the Nd52 is more than or equal to 1.85, so that the spherical aberration can be reduced, and the imaging quality is improved.

The optical performance of the lens provided by the embodiment of the invention is as follows:

according to the zoom lens and the design scheme provided by the embodiment of the invention, the imaging target surface of the lens can be supported by 1 inch at most, and the imaging quality is ensured while the miniaturization of the lens structure is effectively realized. The imaging maximum supports the use of a sensor with a target surface of 1 inch, and the total mechanical length of a lens does not exceed 94 mm; the MTF value of the whole view field reaches more than 0.5 under the condition of 100 lp/mm; the lens has the advantages of less lens number, good processability and low cost control; has infrared confocal performance.

The following exemplifies the lens parameters provided by the embodiment of the present invention.

Example 1:

in a specific implementation process, the curvature radius R, the center thickness Tc, the refractive index Nd, the Abbe constant Vd and the conic coefficient k of each lens of the lens meet the conditions listed in Table 1:

TABLE 1

Note that, the mirror numbers in table 1 are the numbers of the left to right lenses in the schematic view of the lens structure shown in fig. 1;

wherein, the variable thickness data is as shown in the parameter table 2:

focal length	D2	D6	D15	D19
					12mm	6.0	4.85	7.02	0.1
16mm	9.85	1.0	0.1	7.02

TABLE 2

The lens provided by the embodiment has the following optical technical indexes:

the total optical length TTL is less than or equal to 94 mm;

focal length f of the lens: 12(W) mm-16(T) mm;

angle of view of lens: 78.1 ° (W) -60.3 ° (T);

optical distortion of the lens: -8.3% (W) -4.9% (T);

aperture fno of lens system: FNO is less than or equal to 1.6;

size of a lens image plane: 1';

note: w represents short focus, and T represents long focus.

Example 2:

in a specific implementation process, the curvature radius R, the center thickness Tc, the refractive index Nd, the abbe constant Vd and the conic coefficient k of each lens of the lens barrel satisfy the conditions listed in table 3:

TABLE 3

Note that, the mirror numbers in table 3 are the numbers of the left to right lenses in the schematic view of the lens structure shown in fig. 1;

wherein, the variable thickness data is as shown in the parameter table 4:

focal length	D2	D6	D15	D19
					12.3mm	7.60	4.95	6.72	0.1
15.8mm	9.17	3.38	0.95	5.87

TABLE 4

The lens provided by the embodiment has the following optical technical indexes:

the total optical length TTL is less than or equal to 94 mm;

focal length f of the lens: 12.3(W) mm-15.8(T) mm;

angle of view of lens: 70 ° (W) -53 ° (T);

optical distortion of the lens: -7.6% (W) -4.7% (T);

aperture fno of lens system: FNO is less than or equal to 1.6;

size of a lens image plane: 1';

note: w represents short focus, and T represents long focus.

The lens provided by the embodiment is further described below by performing a detailed optical system analysis on the embodiment.

The optical transfer function is used for evaluating the imaging quality of an optical system in a more accurate, visual and common mode, and the higher and smoother curve of the optical transfer function indicates that the imaging quality of the system is better, and aberration is well corrected.

As shown in fig. 1, it is a schematic view of a lens in a short focus state;

as shown in fig. 2, the lens is in a long focus state;

as shown in fig. 3, it is a graph of optical transfer function (MTF) in a short focus state of the lens at a normal temperature state of the visible light band;

as shown in fig. 4, the field curvature and distortion diagram in the visible light band in the short focus state of the lens;

as shown in fig. 5, it is a transverse light fan diagram in the visible light band in the short focus state of the lens;

as shown in fig. 6, it is a dot-sequence diagram of the visible light band in the short focus state of the lens;

as shown in fig. 7, it is a graph of optical transfer function (MTF) in a state of a long focus lens at a normal temperature in a visible light band;

FIG. 8 shows the field curvature and distortion in the visible light band in the telephoto state of the lens;

FIG. 9 is a diagram of the lateral light fan in the visible band in the telephoto state of the lens;

as shown in fig. 10, the diagram is a dot-column diagram of the visible light band in the telephoto state of the lens.

As can be seen from fig. 3, the optical transfer function (MTF) curve in the short focus state of the lens is smooth and concentrated in the visible light portion at normal temperature state, and the average MTF value of the full field of view (half-image height Y' is 4.0mm) is above 0.5; therefore, the lens provided by the embodiment can meet higher imaging requirements in a short-focus state.

As can be seen from fig. 7, the optical transfer function (MTF) curve in the normal temperature state in the visible light portion in the telephoto state is relatively smooth and concentrated, and the average MTF value in the full field of view (half-image height Y' is 4.0mm) is 0.5 or more; therefore, the lens provided by the embodiment can meet higher imaging requirements in a long-focus state.

As can be seen from fig. 4 and 8, the curvature of field in the short focus state of the lens is controlled within ± 0.1mm, and the curvature of field in the long focus state is controlled within ± 0.05 m. The inner curvature of field is also called as "curvature of field". When the lens has field curvature, the intersection point of the whole light beam is not overlapped with an ideal image point, and although a clear image point can be obtained at each specific point, the whole image plane is a curved surface. T represents the meridional field curvature, and S represents the sagittal field curvature. The field curvature curve shows the distance of the current focal plane or image plane to the paraxial focal plane as a function of field coordinates, and the meridional field curvature data is the distance from the currently determined focal plane to the paraxial focal plane measured along the Z axis and measured in the meridional (YZ plane). Sagittal curvature of field data measures distances measured in a plane perpendicular to the meridian plane, the base line in the schematic is on the optical axis, the top of the curve represents the maximum field of view (angle or height), and no units are set on the vertical axis, since the curve is always normalized by the maximum radial field of view.

As can be seen from fig. 4 and 8, the distortion control is good in the short focus state of the lens, and within-8.3%, and the distortion control is good in the long focus state, and within-4.9%. Fig. 4 and 8 both refer to designs of multiple wavelengths (0.486mm, 0.587mm, and 0.656 mm). Generally, lens distortion is a general term of intrinsic perspective distortion of an optical lens, that is, distortion caused by perspective, which is very unfavorable for the imaging quality of a photograph, and after all, the purpose of photography is to reproduce rather than exaggerate, but because the distortion is intrinsic characteristics of the lens (converging light rays of a convex lens and diverging light rays of a concave lens), the distortion cannot be eliminated, and only can be improved. As can be seen from fig. 8, the distortion of the zoom lens provided by the embodiment of the present invention is-8.3% in the short focus state and is only-4.9% in the long focus state; the distortion is set to balance the focal length, the field angle and the size of the target surface of the corresponding camera, and the deformation caused by the distortion can be corrected through post image processing.

As can be seen from fig. 5 and 9, the curves in the sector diagrams are more concentrated, and the spherical aberration and the chromatic dispersion of the lens are better controlled.

As can be seen from fig. 6 and 10, the lens has a small and relatively concentrated light spot radius, and the corresponding aberration and coma are also good.

In summary, the embodiment of the invention provides an optical zoom lens with a large target surface, a large aperture, low cost and high imaging definition. The imaging system adopts 13 optical lenses with specific structural shapes, and the optical lenses are arranged in sequence from the object side to the image side according to a specific sequence, and the specific optical powers of the optical lenses are distributed and combined, so that the imaging system can realize better distortion control and excellent imaging characteristics.

The embodiment of the invention provides a lens, which is composed of a first lens group, a second lens group, a third lens group, an aperture diaphragm, a fourth lens group, a fifth lens group, an optical filter and an image plane which are sequentially arranged from an object side to an image side; the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis; the lens group satisfies the following conditions: wherein f2 is a focal length of the second lens group, f4 is a focal length of the fourth lens group, f_wIs the lens atFocal length in short focal state, f_TFor the focal length, FOV, of the lens in tele state_wFor the field angle, FOV, of the lens in short focus_TThe angle of view of the lens in the telephoto state. Since in the embodiment of the present invention, five lens groups are arranged in the lens in order from the object side to the image side in a specific order, the five lens groups include 13 lenses of specific power, the positions of the first lens group, the third lens group and the fifth lens group are fixed, the second lens group and the fourth lens group can move along the optical axis to realize lens zooming, and the lens groups in the lens satisfy: the high-resolution lens with the large target surface, the large aperture and the low cost is realized.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.