CN211014817U

CN211014817U - Zoom lens

Info

Publication number: CN211014817U
Application number: CN201922355507.XU
Authority: CN
Inventors: 邹文镔; 白兴安; 范家永; 张德伦; 宋光明
Original assignee: Sunny Optics Zhongshan Co Ltd
Current assignee: Sunny Optics Zhongshan Co Ltd
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2020-07-14
Anticipated expiration: 2029-12-23

Abstract

The utility model relates to a zoom lens, include: the lens comprises a first lens group with positive focal power, a second lens group with negative focal power, a diaphragm, a third lens group with positive focal power, a fourth lens group with positive focal power and a fifth lens group with positive focal power, wherein the first lens group, the third lens group and the fifth lens group are fixed lens groups, the second lens group is a zoom group, and the fourth lens group is a focusing group; when the second lens group moves along the optical axis, the magnification is changed from the wide-angle end to the telephoto end; when the fourth lens group moves along the optical axis, the correction and focusing of image surface variation along with zooming are realized; the ratio of the focal length f1 of the first lens group, the focal length f2 of the second lens group, the focal length f3 of the third lens group, the focal length f4 of the fourth lens group, the focal length f5 of the fifth lens group and the focal length fw of the zoom lens at the wide-angle end sequentially satisfies the following ranges: f1, fw is 1.5-10, f2, fw is-3-0.7, f3, fw is 1-6, f4, fw is 1.5-5.5, and f5, fw is 2-8.

Description

Zoom lens

Technical Field

The utility model relates to an optical imaging field especially relates to a zoom lens.

Background

In the security monitoring industry, the pursuit of definition is an important driving force for the development of the industry. From the initial standard definition to the current high definition, full high definition and even ultra high definition, video security monitoring from 'visible' to 'quasi' to the final 'AI identification' is recorded, and the realization of the whole monitoring process depends on the information acquisition of an optical lens, the information transmission of an ultra-large data stream and the image processing at the rear end.

With the rapid development of the commercial 5G technology and the image processing technology, the rapid popularization of 4K monitoring is certainly realized in the near future. The zoom lens with the resolution of 4K can collect monitoring information which is several times higher than that of a conventional fixed-focus lens due to the special working mode of the zoom lens, and the monitoring information is bound to be greatly increased in the field of future security monitoring. However, the existing zoom lens meets the requirement of 4K ultrahigh resolution, and meanwhile, the problems of infrared confocal performance, small aperture value, poor full-focus 4K capability, poor temperature adaptability and the like generally exist.

Disclosure of Invention

An object of the utility model is to solve above-mentioned problem, provide a zoom.

To achieve the above object, the present invention provides a zoom lens, including: the zoom lens comprises a first lens group with positive focal power, a second lens group with negative focal power, a diaphragm, a third lens group with positive focal power, a fourth lens group with positive focal power and a fifth lens group with positive focal power which are sequentially arranged from the object side to the image side along an optical axis, wherein the first lens group, the third lens group and the fifth lens group are fixed lens groups, the second lens group is a zoom group, and the fourth lens group is a focusing group;

when the second lens group moves along the optical axis, the magnification is changed from the wide-angle end to the telephoto end;

when the fourth lens group moves along the optical axis, the correction and focusing of image surface variation along with zooming are realized;

the ratio of the focal length f1 of the first lens group, the focal length f2 of the second lens group, the focal length f3 of the third lens group, the focal length f4 of the fourth lens group, the focal length f5 of the fifth lens group and the focal length fw of the zoom lens at the wide-angle end sequentially satisfies the following ranges:

f1:fw＝1.5～10，f2:fw＝-3～-0.7,f3:fw＝1～6,f4:fw＝1.5～5.5，f5:fw＝2～8。

according to an aspect of the present invention, the first lens group includes a first lens having a negative refractive power, a second lens having a positive refractive power, and a third lens having a positive refractive power;

the first lens is a convex-concave lens.

According to an aspect of the present invention, the second lens group includes a fourth lens having a negative power, a fifth lens having a negative power, a sixth lens having a positive power, and a seventh lens having a negative power;

the fifth lens is a biconcave lens.

According to an aspect of the present invention, the third lens group includes an eighth lens having positive power, a ninth lens having negative power, a tenth lens having positive power, an eleventh lens having negative power, a twelfth lens having positive power, and a thirteenth lens having negative power;

the eighth lens and the twelfth lens are biconvex lenses;

the thirteenth lens is a biconcave lens.

According to an aspect of the present invention, the fourth lens group includes a fourteenth lens having a positive refractive power, a fifteenth lens having a positive refractive power, and a sixteenth lens having a negative refractive power;

the fourteenth lens and the fifteenth lens are double-convex lenses;

the sixteenth lens is a biconcave lens.

According to an aspect of the present invention, the fifth lens group includes a seventeenth lens having a positive power and an eighteenth lens having a negative power;

the seventeenth lens is a biconvex lens.

According to one aspect of the invention, the optical length BF L of the eighteenth lens from the image surface of the zoom lens satisfies 2 < BF L < 13.

According to an aspect of the present invention, the material refractive index range of the seventh lens is 1.35 ~ 1.65.

According to an aspect of the present invention, the refractive index ranges of the materials of the eighth lens and the ninth lens are both 1.35-1.65.

According to an aspect of the present invention, the first lens and the second lens constitute a double cemented lens.

According to an aspect of the present invention, the ninth lens, the tenth lens and the eleventh lens constitute a cemented triplet, and the twelfth lens and the thirteenth lens constitute a cemented doublet.

According to an aspect of the present invention, the fifteenth lens and the sixteenth lens constitute a double cemented lens.

According to the utility model discloses an aspect, the absolute value A of the abbe number difference between two adjacent lenses satisfies in each cemented lens: a is more than 15 and less than 80.

According to an aspect of the present invention, the second lens group, the third lens group and the fourth lens group include at least one aspheric lens.

According to an aspect of the present invention, a distance D between a wide angle end and a telephoto end of the zoom lens and a total length TT L of the zoom lens satisfy 0.15 < D/TT L < 0.536.

According to an aspect of the present invention, a diameter d of the largest lens of the first lens group and a total length TT L of the zoom lens satisfy 0.3 < d/TT L < 2.

According to the zoom lens, through reasonable lens group focal power collocation, the tolerance sensitivity of the optical element is greatly reduced, and the common process is satisfied, so that the mass production can be carried out;

the aperture of the zoom lens is constant, the maximum aperture can reach FNO 1.2, and the zoom lens has a black light level night vision effect through matched image processing;

the utility model discloses a zoom lens has corrected position colour difference and multiplying power colour difference between 420 ~ 940nm through specific material selection, satisfies full focal length section 4K resolution ratio, and full focal length section infrared is confocal, and the camera lens can reach the full focal length section under-40 deg.C ~ 80 deg.C environment simultaneously and not virtual burnt, the very big degree widen the use occasion of camera lens.

Drawings

Fig. 1 is a schematic view showing a zoom lens structure according to a first embodiment of the present invention;

fig. 2 is an MTF chart of the zoom lens according to the first embodiment of the present invention at a wide-angle end at a normal temperature of 20 degrees and under visible light;

fig. 3 is an MTF chart of a zoom lens according to a first embodiment of the present invention at a normal temperature of 20 degrees and a night infrared angle of 850 nm;

fig. 4 is an MTF diagram of a telephoto end of the zoom lens according to the first embodiment of the present invention at normal temperature of 20 degrees under visible light;

fig. 5 is an MTF chart of the zoom lens according to the first embodiment of the present invention at a telephoto end of infrared 850nm at room temperature and 20 degrees at night;

fig. 6 is an MTF chart of the zoom lens according to the first embodiment of the present invention at a wide-angle end at a low temperature of-40 degrees and under visible light;

fig. 7 is an MTF chart of the zoom lens according to the first embodiment of the present invention at a wide angle end at a high temperature of 80 degrees and under visible light;

fig. 8 is a MTF chart of the telephoto end of the zoom lens according to the first embodiment of the present invention at low temperature of-40 degrees under visible light;

fig. 9 is an MTF graph of the telephoto end of the zoom lens according to the first embodiment of the present invention at a high temperature of 80 degrees under visible light.

Fig. 10 is a schematic view showing a zoom lens structure according to a second embodiment of the present invention;

fig. 11 is an MTF chart of the zoom lens system according to the second embodiment of the present invention at a wide angle end at a normal temperature of 20 degrees and under visible light;

fig. 12 is an MTF chart of a zoom lens according to a second embodiment of the present invention at a normal temperature of 20 degrees and a night infrared angle of 850 nm;

fig. 13 is an MTF chart of a telephoto end of the zoom lens according to the second embodiment of the present invention at normal temperature of 20 degrees under visible light;

fig. 14 is an MTF chart of a zoom lens according to a second embodiment of the present invention at a telephoto end of infrared 850nm at room temperature and 20 degrees at night;

fig. 15 is an MTF chart of the zoom lens according to the second embodiment of the present invention at a wide-angle end at low temperature of-40 degrees and under visible light;

fig. 16 is an MTF chart of the zoom lens according to the second embodiment of the present invention at a wide angle end at a high temperature of 80 degrees and under visible light;

fig. 17 is an MTF chart of a telephoto end of the zoom lens according to the second embodiment of the present invention at low temperature of-40 degrees under visible light;

fig. 18 is an MTF chart of the telephoto end at a high temperature of 80 degrees under visible light in the zoom lens according to the second embodiment of the present invention.

Fig. 19 is a schematic view showing a zoom lens structure according to a third embodiment of the present invention;

fig. 20 is an MTF chart of a zoom lens according to a third embodiment of the present invention at a wide angle end at a normal temperature of 20 degrees and under visible light;

fig. 21 is an MTF chart of a zoom lens according to a third embodiment of the present invention at a normal temperature of 20 degrees and a night infrared angle of 850 nm;

fig. 22 is an MTF chart of a telephoto end of the zoom lens according to the third embodiment of the present invention at normal temperature of 20 degrees under visible light;

fig. 23 is an MTF chart of a zoom lens according to a third embodiment of the present invention at a telephoto end of infrared 850nm at normal temperature and 20 degrees at night;

fig. 24 is an MTF chart of a zoom lens according to a third embodiment of the present invention at a wide-angle end at a low temperature of-40 degrees and under visible light;

fig. 25 is an MTF chart at the wide-angle end at a high temperature of 80 degrees and under visible light in the zoom lens according to the third embodiment of the present invention;

fig. 26 is an MTF chart of a telephoto end of the zoom lens according to the third embodiment of the present invention at low temperature of-40 degrees under visible light;

fig. 27 is an MTF chart of the telephoto end at a high temperature of 80 degrees under visible light in the zoom lens according to the third embodiment of the present invention.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

In describing embodiments of the present invention, the terms "longitudinal," "lateral," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and other terms are used in an orientation or positional relationship shown in the associated drawings for convenience in describing the invention and for simplicity in description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the invention.

The present invention will be described in detail with reference to the accompanying drawings and specific embodiments, which are not repeated herein, but the present invention is not limited to the following embodiments.

Fig. 1 schematically shows a configuration diagram of a zoom lens according to an embodiment of the present invention. As shown in fig. 1, the zoom lens of the present invention includes a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a stop S, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having positive refractive power, and a protective glass CG, which are arranged in this order from an object side to an image side along an optical axis. In the present invention, the first lens group G1, the third lens group G3, and the fifth lens group G5 are fixed lens groups, the second lens group G2 is a zoom group, and the fourth lens group G4 is a focus group.

In the present invention, when the second lens group G2 moves along the optical axis, zooming from the wide-angle end to the telephoto end is realized. When the fourth lens group G4 moves along the optical axis, correction of image plane variation and focusing accompanying magnification change are realized.

In the present invention, the ratio of the focal length f1 of the first lens group G1, the focal length f2 of the second lens group G2, the focal length f3 of the third lens group G3, the focal length f4 of the fourth lens group G4, and the focal length f5 of the fifth lens group G5 to the focal length fw of the wide-angle end of the zoom lens sequentially satisfies the following ranges:

in the present invention, the first lens group G1 includes a first lens L1 having a negative refractive power, a second lens L2 having a positive refractive power, and a third lens L3 having a positive refractive power, in which the first lens L1 is a convex-concave lens.

The second lens group G2 includes a fourth lens L4 having negative power, a fifth lens L5 having negative power, a sixth lens L6 having positive power, and a seventh lens L7 having negative power, in which the fifth lens L5 is a biconcave lens.

The third lens group G3 includes an eighth lens L8 having positive power, a ninth lens L9 having negative power, a tenth lens L10 having positive power, an eleventh lens L11 having negative power, a twelfth lens L12 having positive power, and a thirteenth lens L13 having negative power, wherein the eighth lens L8 and the twelfth lens L12 are double convex lenses, and the thirteenth lens L13 is a double concave lens.

The fourth lens group G4 includes a fourteenth lens L14 having positive power, a fifteenth lens L15 having positive power, and a sixteenth lens L16 having negative power, wherein the fourteenth lens L14 and the fifteenth lens L15 are double convex lenses, and the sixteenth lens L16 is a double concave lens.

The fifth lens group L5 includes a seventeenth lens L17 having positive optical power and an eighteenth lens L18 having negative optical power, wherein the seventeenth lens L17 is a biconvex lens, and an optical length BF L of the eighteenth lens L18 from an image plane of the zoom lens satisfies 2 < BF L < 13.

In the present invention, the refractive index ranges of the materials of the seventh lens L7, the eighth lens L8, and the ninth lens L9 are all 1.35-1.65.

Preferably, the first lens L1 and the second lens L2 constitute a double cemented lens, the ninth lens L9, the tenth lens L10, and the eleventh lens L11 constitute a triple cemented lens, the twelfth lens L12 and the thirteenth lens L13 constitute a double cemented lens, and the fifteenth lens L15 and the sixteenth lens L16 constitute a double cemented lens, and the absolute value A of the Abbe number difference between adjacent two lenses among the above cemented lenses satisfies 15 < A < 80.

In the present invention, at least one of the second lens group G2, the third lens group G3, and the fourth lens group G4 is preferably a glass aspherical lens. And the aspheric surface satisfies the following formula:

wherein z is the axial distance from the curved surface to the vertex at the position with the height h perpendicular to the optical axis along the direction of the optical axis; c represents the curvature at the apex of the aspherical surface; k is a conic coefficient; a4, a6, A8, a10 and a12 respectively represent aspheric coefficients of fourth, sixth, eighth and twelfth orders.

The distance D between the second lens group G2 moving from the wide angle end to the telephoto end of the zoom lens and the total length TT L of the zoom lens satisfy 0.15 < D/TT L < 0.536, and the diameter D of the largest lens in the first lens group G1 and the total length TT L of the zoom lens satisfy 0.3 < D/TT L < 2.

According to the zoom lens of the utility model, through reasonable lens group focal power collocation, the tolerance sensitivity of the optical element is greatly reduced, and the common process is satisfied, and mass production can be carried out;

Since the zoom lens according to the present invention has 18 lenses in total, in the first to third embodiments, the first lens L1 and the second lens L2 constitute a double cemented lens, the ninth lens L9, the tenth lens L10 and the eleventh lens L11 constitute a triple cemented lens, the twelfth lens L12 and the thirteenth lens L13 constitute a double cemented lens, the fifteenth lens L15 and the sixteenth lens L16 constitute a double cemented lens, the diaphragm S, the imaging plane IMA of the lens, and the total of 35 planes, for convenience of description, the respective plane numbers are designated as S1 to S35.

The first implementation mode comprises the following steps:

fig. 1 is a schematic view showing a zoom lens structure according to a first embodiment of the present invention.

The aperture FNO in the first embodiment is 1.38.

Table 1 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:

TABLE 1

In this embodiment, the aspheric data is shown in table 2 below, where K is the conic constant of the surface, and A, B, C, D, E are aspheric coefficients of fourth, sixth, eighth, tenth, and twelfth orders, respectively:

number of noodles

K

A

B

C

D

E

S15

0.354

-3.87E-06

3.34E-08

-9.75E-10

1.58E-11

-1.87E-13

S16

-1

1.20E-05

1.54E-08

-7.02E-10

1.18E-11

-1.73E-13

TABLE 2

In the present embodiment, the wide-angle end and telephoto end magnification variation data of the zoom lens are as shown in table 3 below:

TABLE 3

In this embodiment, the ratio of the focal length f1 of the first lens group G1, the focal length f2 of the second lens group G2, the focal length f3 of the third lens group G3, the focal length f4 of the fourth lens group G4, and the focal length f5 of the fifth lens group G5 to the focal length fw of the zoom lens at the wide-angle end is, in order: 3.83, -0.96, 2.937, 2.153 and 5.404.

The eighth lens L8 of the third lens group G3 is an aspherical lens;

the distance D between the second lens group G2 moving from the wide angle end to the telephoto end of the zoom lens and the total length TT L of the zoom lens meets the condition that D/TT L is 0.245;

d/TT L is 0.425;

the refractive index of the seventh lens L7 is 1.52, the refractive index of the eighth lens L8 is 1.62, and the refractive index of the ninth lens L9 is 1.62;

the optical length BF L of the eighteenth lens L18 from the image plane is 6 mm.

Fig. 2 to 9 show MTF graphs at a wide-angle end of the zoom lens according to the first embodiment of the present invention at a normal temperature of 20 degrees and under visible light, respectively; MTF graph of infrared 850nm long wide angle at normal temperature of 20 deg.C and night; MTF graph of long focal length under visible light at normal temperature of 20 ℃; MTF graph of infrared 850nm long focus end at normal temperature of 20 deg.C and night; MTF graph at the wide-angle end at low temperature of 40 ℃ below zero and under visible light; MTF plot at high temperature 80 ℃ under visible light at wide angle end; MTF graph of tele end at low temperature-40 deg.C under visible light; MTF plot of tele end at 80 deg.C under visible light.

As can be seen from fig. 2 to 9, according to the arrangement of the zoom lens of the present embodiment, positional chromatic aberration and magnification chromatic aberration between 420 nm and 940nm are corrected, a full-focus segment with a resolution of 4K is satisfied, and a full-focus segment with infrared confocal is satisfied, and meanwhile, the lens can achieve the characteristics that the full-focus segment is not virtual focus and the optical element sensitivity is low under an environment of-40 ℃ to 80 ℃.

The second embodiment:

fig. 10 is a schematic view showing a zoom lens structure according to a second embodiment of the present invention.

The aperture FNO in the second embodiment is 1.2.

Table 4 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:

number of noodles	Surface type	R value	Thickness of	Refractive index	Abbe number
						OBJ	Spherical surface	inf	inf
S1	Spherical surface	78.475	1.40	1.90	22.9
						S2	Spherical surface	50.000	5.61	1.52	81.2
S3	Spherical surface	-146.207	0.10
						S4	Spherical surface	40.000	4.29	1.63	70.3
S5	Spherical surface	116.752	T1
						S6	Spherical surface	-100.000	0.48	1.69	32.2
S7	Spherical surface	14.798	3.61
						S8	Spherical surface	-37.953	0.50	1.60	61.5
S9	Spherical surface	32.580	0.70
						S10	Spherical surface	25.989	1.95	2.10	18.3
S11	Spherical surface	365.231	1.40
						S12	Aspherical surface	-26.230	0.48	1.53	56
S13	Aspherical surface	130.633	T2
						Stop	Spherical surface	inf	0.76
S15	Aspherical surface	50.000	3.81	1.62	63.4
						S16	Aspherical surface	-47.624	0.11
S17	Spherical surface	50.000	3.55	1.61	39.0
						S18	Spherical surface	9.424	11.82	1.62	63.4
S19	Spherical surface	-15.000	0.48	1.80	24.5
						S20	Spherical surface	17.737	2.81
S21	Spherical surface	30.000	2.80	2.10	18.3
						S22	Spherical surface	-107.242	0.49	1.79	25.2
S23	Spherical surface	12.697	T3
						S24	Spherical surface	60.242	1.64	1.72	55.8
S25	Spherical surface	-60.242	0.10
						S26	Spherical surface	16.360	3.54	1.72	55.8
S27	Spherical surface	-25.124	0.48	1.69	32.2
						S28	Spherical surface	16.436	T4
S29	Spherical surface	30.000	2.54	1.81	22.7
						S30	Spherical surface	-40.401	1.30
S31	Spherical surface	-24.141	0.49	1.80	46.6
						S32	Spherical surface	-80.000	1.22
S33	Spherical surface	inf	1.20	1.52	64.2
						S34	Spherical surface	inf	8.30
S35(IMA)	Spherical surface	inf

TABLE 4

In this embodiment, the aspheric data is shown in table 5 below, where K is the conic constant of the surface, and A, B, C, D, E are aspheric coefficients of fourth, sixth, eighth, tenth, and twelfth orders, respectively:

number of noodles

K

A

B

C

D

E

S12

1.000

-8.51E-06

7.35E-08

-2.15E-09

3.48E-11

-4.12E-13

S13

-1.00

2.65E-05

3.38E-08

-1.54E-09

2.59E-11

-3.80E-13

S15

0.389

-4.25E-06

3.67E-08

-1.07E-09

1.74E-11

-2.06E-13

S16

-1.15

1.32E-05

1.69E-08

-7.72E-10

1.29E-11

-1.90E-13

TABLE 5

In the present embodiment, the wide-angle end and telephoto end magnification variation data of the zoom lens are as shown in table 6 below:

	wide angle end	Long coke end
			T1	2	17.5
T2	18	2.5
			T3	8.20135	5.0453
T4	1.82	4.951

TABLE 6

In this embodiment, the ratio of the focal length f1 of the first lens group G1, the focal length f2 of the second lens group G2, the focal length f3 of the third lens group G3, the focal length f4 of the fourth lens group G4, and the focal length f5 of the fifth lens group G5 to the focal length fw of the zoom lens at the wide-angle end is, in order: 3.74, -0.808, 3.415, 1.778, and 2.483.

The distance D between the second lens group G2 moving from the wide angle end to the telephoto end of the zoom lens and the total length TT L of the zoom lens meets the condition that D/TT L is 0.171;

d/TT L is 0.383;

the refractive index of the seventh lens L7 is 1.53, the refractive index of the eighth lens L8 is 1.62, and the refractive index of the ninth lens L9 is 1.62;

the optical length BF L of the eighteenth lens L18 from the image plane is 10.3 mm.

Fig. 11 to 18 are MTF graphs of a zoom lens according to a second embodiment of the present invention at a wide-angle end at a normal temperature of 20 degrees and under visible light, respectively; MTF graph of infrared 850nm long wide angle at normal temperature of 20 deg.C and night; MTF graph of long focal length under visible light at normal temperature of 20 ℃; MTF graph of infrared 850nm long focus end at normal temperature of 20 deg.C and night; MTF graph at the wide-angle end at low temperature of 40 ℃ below zero and under visible light; MTF plot at high temperature 80 ℃ under visible light at wide angle end; MTF graph of tele end at low temperature-40 deg.C under visible light; MTF plot of tele end at 80 deg.C under visible light.

As can be seen from fig. 11 to 18, according to the arrangement of the zoom lens of the present embodiment, positional chromatic aberration and magnification chromatic aberration between 420 nm and 940nm are corrected, a full-focus segment with a resolution of 4K is satisfied, and a full-focus segment with infrared confocal is satisfied, and meanwhile, the lens can achieve the characteristics that the full-focus segment is not virtual focus and the optical element sensitivity is low in an environment of-40 ℃ to 80 ℃.

The third embodiment is as follows:

fig. 19 is a schematic view showing a zoom lens structure according to a third embodiment of the present invention.

The aperture FNO in the second embodiment is 1.62.

Table 7 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:

TABLE 7

In this embodiment, the aspheric data is shown in table 8 below, where K is the conic constant of the surface, and A, B, C, D, E are aspheric coefficients of fourth, sixth, eighth, tenth, and twelfth orders, respectively:

TABLE 8

In the present embodiment, the wide-angle end and telephoto end magnification variation data of the zoom lens are as shown in table 9 below:

	wide angle end	Long coke end
			T1	3.15	20.925
T2	19	1.225
			T3	8	6.7993
T4	2.022	3.197

TABLE 9

In this embodiment, the ratio of the focal length f1 of the first lens group G1, the focal length f2 of the second lens group G2, the focal length f3 of the third lens group G3, the focal length f4 of the fourth lens group G4, and the focal length f5 of the fifth lens group G5 to the focal length fw of the zoom lens at the wide-angle end is, in order: 2.11, -0.53, 3.133, 1.192, and 7.9.

The distance D between the second lens group G2 moving from the wide angle end to the telephoto end of the zoom lens and the total length TT L of the zoom lens meets the condition that D/TT L is 0.203;

d/TT L is 0.335 between the diameter d of the largest lens in the first lens group G1 and the total length TT L of the zoom lens;

the refractive index of the seventh lens L7 is 1.53, the refractive index of the eighth lens L8 is 1.66, and the refractive index of the ninth lens L9 is 1.66;

the optical length BF L of the eighteenth lens L18 from the image plane is 5 mm.

Fig. 20 to 27 are MTF graphs of a zoom lens according to a third embodiment of the present invention at a wide angle end at a normal temperature of 20 degrees and under visible light, respectively; MTF graph of infrared 850nm long wide angle at normal temperature of 20 deg.C and night; MTF graph of long focal length under visible light at normal temperature of 20 ℃; MTF graph of infrared 850nm long focus end at normal temperature of 20 deg.C and night; MTF graph at the wide-angle end at low temperature of 40 ℃ below zero and under visible light; MTF plot at high temperature 80 ℃ under visible light at wide angle end; MTF graph of tele end at low temperature-40 deg.C under visible light; MTF plot of tele end at 80 deg.C under visible light.

As can be seen from fig. 20 to 27, according to the arrangement of the zoom lens of the present embodiment, positional chromatic aberration and magnification chromatic aberration between 420 nm and 940nm are corrected, a full-focus segment with a resolution of 4K is satisfied, and a full-focus segment with infrared confocal is satisfied, and meanwhile, the lens can achieve the characteristics that the full-focus segment is not virtual focus and the optical element sensitivity is low in an environment of-40 ℃ to 80 ℃.

The above description is only one embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A zoom lens, comprising: a first lens group (G1) having positive optical power, a second lens group (G2) having negative optical power, a diaphragm (S), a third lens group (G3) having positive optical power, a fourth lens group (G4) having positive optical power, and a fifth lens group (G5) having positive optical power, which are arranged in order from the object side to the image side along the optical axis, wherein the first lens group (G1), the third lens group (G3), and the fifth lens group (G5) are fixed lens groups, the second lens group (G2) is a zoom group, and the fourth lens group (G4) is a focus group;

the second lens group (G2) realizes magnification variation from the wide-angle end to the telephoto end when moving along the optical axis;

when the fourth lens group (G4) moves along the optical axis, the correction and focusing of image surface variation along with zooming are realized;

wherein, the ratio of the focal length f1 of the first lens group (G1), the focal length f2 of the second lens group (G2), the focal length f3 of the third lens group (G3), the focal length f4 of the fourth lens group (G4), and the focal length f5 of the fifth lens group (G5) to the focal length fw at the wide angle end of the zoom lens satisfies the following ranges in order:

2. the zoom lens according to claim 1, wherein the first lens group (G1) includes a first lens (L1) having negative optical power, a second lens (L2) having positive optical power, and a third lens (L3) having positive optical power;

the first lens (L1) is a convex-concave lens.

3. The zoom lens according to claim 1, wherein the second lens group (G2) includes a fourth lens (L4) having a negative optical power, a fifth lens (L5) having a negative optical power, a sixth lens (L6) having a positive optical power, and a seventh lens (L7) having a negative optical power;

the fifth lens (L5) is a biconcave lens.

4. The zoom lens according to claim 1, wherein the third lens group (G3) includes an eighth lens (L8) having positive optical power, a ninth lens (L9) having negative optical power, a tenth lens (L10) having positive optical power, an eleventh lens (L11) having negative optical power, a twelfth lens (L12) having positive optical power, and a thirteenth lens (L13) having negative optical power;

the eighth lens (L8) and the twelfth lens (L12) are double convex lenses;

the thirteenth lens (L13) is a biconcave lens.

5. The zoom lens according to claim 1, wherein the fourth lens group (G4) includes a fourteenth lens (L14) having positive optical power, a fifteenth lens (L15) having positive optical power, and a sixteenth lens (L16) having negative optical power;

the fourteenth lens (L14) and the fifteenth lens (L15) are double-convex lenses;

the sixteenth lens (L16) is a biconcave lens.

6. The zoom lens according to claim 1, wherein the fifth lens group (G5) includes a seventeenth lens (L17) having a positive optical power and an eighteenth lens (L18) having a negative optical power;

the seventeenth lens (L17) is a biconvex lens.

7. The zoom lens according to claim 6, wherein an optical length BF L of the eighteenth lens (L18) from an image plane of the zoom lens satisfies 2 < BF L < 13.

8. The zoom lens according to claim 3, wherein the refractive index of the material of the seventh lens (L7) is in a range of 1.35-1.65.

9. The zoom lens according to claim 4, wherein the refractive indices of the materials of the eighth lens (L8) and the ninth lens (L9) are in a range of 1.35 to 1.65.

10. A zoom lens according to claim 2, wherein the first lens (L1) and the second lens (L2) constitute a double cemented lens.

11. The zoom lens according to claim 4, wherein the ninth lens (L9), the tenth lens (L10), and the eleventh lens (L11) constitute a triple cemented lens, and the twelfth lens (L12) and the thirteenth lens (L13) constitute a double cemented lens.

12. The zoom lens according to claim 5, wherein the fifteenth lens (L15) and the sixteenth lens (L16) constitute a double cemented lens.

13. The zoom lens according to any one of claims 10 to 12, wherein an absolute value a of an abbe number difference between adjacent two lenses in each cemented lens satisfies: a is more than 15 and less than 80.

14. The zoom lens according to any one of claims 1 to 12, wherein at least one of the second lens group (G2), the third lens group (G3), and the fourth lens group (G4) includes an aspherical lens.

15. The zoom lens according to any one of claims 1 to 12, wherein a distance D by which the second lens group (G2) moves from a wide angle end to a telephoto end of the zoom lens and a total length TT L of the zoom lens satisfy 0.15 < D/TT L < 0.536.

16. The zoom lens according to any one of claims 1 to 12, wherein a diameter d of a largest lens of the first lens group (G1) and a total length TT L of the zoom lens satisfy 0.3 < d/TT L < 2.