CN218767552U

CN218767552U - Zoom lens

Info

Publication number: CN218767552U
Application number: CN202222778476.0U
Authority: CN
Inventors: 梁伟朝; 应永茂; 周静
Original assignee: Sunny Optics Zhongshan Co Ltd
Current assignee: Sunny Optics Zhongshan Co Ltd
Priority date: 2022-10-20
Filing date: 2022-10-20
Publication date: 2023-03-28
Anticipated expiration: 2032-10-20

Abstract

The utility model relates to a zoom lens follows the direction of optical axis from the thing side to picture side, includes in proper order: the zoom lens comprises a compensation lens group (G1) with negative focal power, a first fixed lens group (G2) with positive focal power, a diaphragm (STO), a zoom lens group (G3) with positive focal power, a second fixed lens group (G4) with positive focal power, a parallel flat plate (CG) and an image plane (IMA), wherein the compensation lens group (G1) and the zoom lens group (G3) can move along the optical axis. The utility model discloses a zoom can realize being about 2.5 times zoom than, satisfies the full focus simultaneously and realizes that visible light and infrared light are confocal, and can realize the biggest light ring 1.05 at the zoom in-process.

Description

Zoom lens

Technical Field

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

Background

The zoom lens has the characteristic of variable focal length, and can meet the requirements of various monitoring scenes, so that the zoom lens is widely concerned and widely applied in security monitoring and intelligent traffic markets. With the improvement of attention, the market also has higher requirements on the image acquisition function of the zoom lens. Specifically, the zoom lens with a powerful image acquisition function needs to ensure that large-aperture zooming can be realized in a full focal length range and confocal visible light and infrared light can be realized in the full focal length range under the condition of meeting the requirement of high resolution. The zoom lens with the characteristics has a great application prospect. However, the conventional zoom lens generally cannot satisfy the above requirements.

SUMMERY OF THE UTILITY MODEL

For solving the problem that exists among the above-mentioned prior art, the utility model aims to provide a zoom can realize being about the zoom ratio of 2.5 times, satisfies the full focal length within range simultaneously and realizes that visible light and infrared light are confocal, and can realize the biggest light ring 1.05 at the zoom in-process.

To achieve the above object, the present invention provides a zoom lens, sequentially including, in a direction from an object side to an image side along an optical axis: the zoom lens comprises a compensation lens group with negative focal power, a first fixed lens group with positive focal power, a diaphragm, a zoom lens group with positive focal power, a second fixed lens group with positive focal power, a parallel flat plate and an image surface, wherein the compensation lens group and the zoom lens group can move along the optical axis.

According to an aspect of the present invention, along the direction of the optical axis from the object side to the image side, the compensation lens group includes in order: a first lens, a second lens, a third lens and a fourth lens,

the first lens and the fourth lens have negative optical power.

According to an aspect of the present invention, in a direction from an object side to an image side along an optical axis,

the first lens is a convex-concave lens;

the second lens is a concave-convex lens, a concave-concave lens or a convex-convex lens;

the third lens is a concave-convex lens or a concave-convex lens;

the object side surface of the fourth lens is concave in shape.

According to an aspect of the present invention, the first fixed lens group includes: a fifth lens of positive optical power.

According to an aspect of the present invention, the object side surface of the fifth lens is convex in shape.

According to an aspect of the present invention, along the direction of the optical axis from the object side to the image side, the variable power lens group includes in order: a sixth lens, a seventh lens, an eighth lens, and a ninth lens,

the sixth lens and the ninth lens have positive optical power.

the sixth lens is a convex lens;

the seventh lens is a convex-convex lens, a concave-convex lens or a concave-concave lens;

the eighth lens is a concave-concave lens, a convex-concave lens or a convex-convex lens;

the ninth lens is a convex lens or a concave-convex lens.

According to an aspect of the present invention, the focal length F6 of the sixth lens element and the focal length F3 of the zoom lens group satisfy the following conditional expression: F6/F3 is more than or equal to 1.08 and less than or equal to 1.90.

According to an aspect of the present invention, the focal length F9 of the ninth lens and the focal length F3 of the variable power lens group satisfy the following conditional expression: F9/F3 is more than or equal to 0.99 and less than or equal to 4.48.

According to an aspect of the utility model discloses, zoom lens group still includes: a fifteenth lens, the fifteenth lens being located between the first fixed lens group and the sixth lens.

According to an aspect of the present invention, the fifteenth lens is a convex-concave lens or a convex-convex lens in a direction from the object side to the image side along the optical axis.

According to an aspect of the present invention, along the direction of the optical axis from the object side to the image side, the second fixed lens group includes in order: a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, and a fourteenth lens,

the tenth lens, the twelfth lens, and the fourteenth lens have negative optical power, and the eleventh lens and the thirteenth lens have positive optical power.

the tenth lens and the twelfth lens are concave-concave lenses;

the eleventh lens and the thirteenth lens are convex lenses;

the fourteenth lens is a concave-concave lens, a convex-concave lens, or a meniscus lens.

According to an aspect of the present invention, the second fixed lens group further includes: a sixteenth lens of positive optical power positioned between the fourteenth lens and the parallel plate.

According to an aspect of the present invention, the sixteenth lens is a convex-concave lens or a convex-convex lens in a direction from the object side to the image side along the optical axis.

According to an aspect of the present invention, the variable power lens group includes at least 1 cemented lens.

According to an aspect of the present invention, the zoom lens includes 2 aspheric lenses at least, wherein include 1 glass aspheric lens at least.

According to an aspect of the present invention, the moving distance T1 of the compensation lens group and the moving distance T2 of the zoom lens group satisfy the following conditional expressions: T1/T2 is more than or equal to 0.54 and less than or equal to 1.62.

According to an aspect of the utility model, the focus F1 of compensation lens group with the focus F3 of zoom lens group satisfies following conditional expression: F1/F3 is more than or equal to-0.71 and less than or equal to-0.55.

According to the utility model discloses a scheme, by the focal power in proper order for the burden, just, positive compensation, it is first fixed, zoom and four fixed lens groups of second and be located the zoom optical system that the diaphragm etc. between first fixed lens group and the zoom lens group constitute, the mode of actuating between so specific lens group and the lens quantity in every lens group, focal power and shape optimize the setting and make up, it is fast not only to make the camera lens in the in-process response speed of zooming focus, and can make this zoom realize about the zoom ratio of 2.5 times, satisfy the confocal performance of visible light and infrared light in the full focal length scope simultaneously, and can realize biggest light ring 1.05 at the zoom in-process, compromise miniaturized design.

Drawings

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.

Fig. 1 is a schematic view of an optical system of a zoom lens according to a first embodiment of the present invention at a wide-angle end;

fig. 2 schematically illustrates an optical system diagram of a wide-angle end of a zoom lens according to a second embodiment of the present invention;

fig. 3 is a schematic view of an optical system of a zoom lens according to a third embodiment of the present invention at a wide-angle end;

fig. 4 is a schematic view of an optical system of a zoom lens according to a fourth embodiment of the present invention at a wide-angle end;

fig. 5 is a schematic view of an optical system of a zoom lens according to a fifth embodiment of the present invention at a wide-angle end;

fig. 6 is a schematic view of an optical system of a zoom lens according to a sixth embodiment of the present invention at a wide-angle end;

fig. 7 schematically illustrates an optical system diagram of a seventh zoom lens according to the present invention at a wide angle end.

Detailed Description

The embodiments described in this specification are to be considered in all respects as illustrative and not restrictive, and the accompanying drawings are intended to be part of the entire specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and simplified or conveniently indicated. Further, the components of the structures in the drawings are described separately, and it should be noted that the components not shown or described in the drawings are well known to those skilled in the art.

Any reference to directions and orientations to the description of the embodiments herein is merely for convenience of description and should not be construed as limiting the scope of the present invention in any way. The following description of the preferred embodiments refers to combinations of features which may be present individually or in combination, and the present invention is not limited to the preferred embodiments in particular. The scope of the present invention is defined by the claims.

As shown in fig. 1, an embodiment of the present invention provides a zoom lens, sequentially including, along an optical axis from an object side to an image side: the zoom lens system comprises a compensation lens group G1, a first fixed lens group G2, a diaphragm STO, a zoom lens group G3, a second fixed lens group G4, a parallel flat plate CG and an image plane IMA, wherein the compensation lens group G1 and the zoom lens group G3 can move along an optical axis. The compensation lens group G1 is a lens group having negative focal power, and the first fixed lens group G2, the variable power lens group G3, and the second fixed lens group G4 are all lens groups having positive focal power. Therefore, by reasonably distributing the actuating modes and the focal powers of the four lens groups, the zoom lens can realize the zoom ratio of about 2.5 times, simultaneously meet the requirement of realizing the confocal of visible light and infrared light in the full focal length range, and realize the maximum aperture of 1.05 in the zoom process.

In an embodiment of the present invention, along the direction from the object side to the image side along the optical axis, the compensation lens group G1 sequentially includes: a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4. Wherein the first lens L1 and the fourth lens L4 are both lenses having negative optical power. Regarding the lens shape, in the direction from the object side to the image side along the optical axis, the first lens L1 is a convex-concave lens, the second lens L2 is a concave-convex lens, a concave-concave lens, or a convex-convex lens, the third lens L3 is a concave-concave lens or a convex-concave lens, and the object-side surface of the fourth lens L4 is concave, that is, the fourth lens L4 is a concave-concave lens, a concave-flat lens, or a concave-convex lens.

In an embodiment of the present invention, the first fixed lens group G2 includes: and a fifth lens L5. The fifth lens L5 is a lens having positive optical power. Regarding the lens shape, the shape of the object-side surface of the fifth lens L5 is convex, i.e., in the direction from the object side to the image side along the optical axis, and the fifth lens L5 is a convex-concave lens, a convex-convex lens, or a convex-flat lens.

In an embodiment of the present invention, along the direction from the object side to the image side along the optical axis, the variable magnification lens group G3 sequentially includes: a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9. Wherein, the sixth lens L6 and the ninth lens L9 are both lenses having positive optical power. Regarding the lens shape, in a direction from the object side to the image side along the optical axis, the sixth lens L6 is a convex lens, the seventh lens L7 is a convex lens, a concave-convex lens, or a concave-concave lens, the eighth lens L8 is a concave-concave lens, a convex-concave lens, or a convex-convex lens, and the ninth lens L9 is a convex-convex lens or a concave-convex lens.

In the embodiment of the present invention, the variable power lens group G3 further includes a fifteenth lens L15, as shown in fig. 1 or fig. 4 to 7. The fifteenth lens L15 is located between the first fixed lens group G2 and the sixth lens L6. With respect to the lens shape, the fifteenth lens L15 is a convex-concave lens or a convex-convex lens in a direction from the object side to the image side along the optical axis.

In an embodiment of the present invention, along the direction from the object side to the image side along the optical axis, the second fixed lens group G4 includes in order: a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, and a fourteenth lens L14. Among them, the tenth lens L10, the twelfth lens L12, and the fourteenth lens L14 are all lenses having negative power, and the eleventh lens L11 and the thirteenth lens L13 are all lenses having positive power. With respect to the lens shape, in the direction from the object side to the image side along the optical axis, the tenth lens L10 and the twelfth lens L12 are both concave-concave lenses, the eleventh lens L11 and the thirteenth lens L13 are both convex-convex lenses, and the fourteenth lens L14 is a concave-concave lens, a convex-concave lens, or a meniscus lens.

In the embodiment of the present invention, the second fixed lens group G4 further includes a sixteenth lens L16, as shown in fig. 1 to 4, 6 or 7. The sixteenth lens L16 is a lens having positive power, and is located between the fourteenth lens L14 and the parallel plate CG. Regarding the lens shape, the sixteenth lens L16 is a convex-concave lens or a convex-convex lens in a direction from the object side to the image side along the optical axis.

According to the above technical scheme of the embodiment of the utility model, through rational distribution and the lens combination of optimizing lens quantity and different focal power, different shapes that set up in four lens groups, further be favorable to zoom to realize about 2.5 times zoom than, satisfy simultaneously that the full focal length within range realizes that visible light and infrared light are confocal to satisfy and zoom the in-process and can realize the biggest light ring 1.05.

In the embodiment of the present invention, the focal length F6 of the sixth lens L6 and the focal length F3 of the variable magnification lens group G3 satisfy the following conditional expression: F6/F3 is more than or equal to 1.08 and less than or equal to 1.90. The focal length F9 of the ninth lens L9 and the focal length F3 of the variable power lens group G3 satisfy the following conditional expression: F9/F3 is more than or equal to 0.99 and less than or equal to 4.48. Therefore, the focal power and the shape of each lens in the variable power lens group G3 and the focal lengths of the sixth lens L6 and the ninth lens L9 with positive focal power are reasonably distributed, so that the confocal of the zoom lens in the full focal length range can be realized.

In the embodiment of the present invention, the zoom lens group G3 at least contains 1 cemented lens. The number of the cemented lenses is reasonably set in the zoom optical system, which is beneficial to correcting the aberration of the system and improving the optical performance of the zoom lens. Meanwhile, the chromatic aberration of the system can be effectively corrected, and the zoom lens is favorable for realizing the confocal of visible light and infrared light. And the assembling tolerance between the lenses can be reduced, and the assembling yield of the zoom lens can be improved.

In an embodiment of the present invention, the zoom lens includes at least 2 aspheric lenses, and at least 1 glass aspheric lens. This may be advantageous in providing optical imaging performance of the zoom lens.

The embodiment of the utility model provides an in, the moving distance T1 of compensation lens group G1 and the moving distance T2 of zoom lens group G3 satisfy following conditional expression: T1/T2 is more than or equal to 0.54 and less than or equal to 1.62. The relationship between the moving distances of the compensation lens group G1 and the variable magnification lens group G3 is limited, so that the focusing response speed of the zoom lens is high in the zooming process, and the zoom lens is miniaturized.

The embodiment of the utility model provides an in, the following conditional expression is satisfied with the focus F3 of the variable power battery of lens group G3 to the focus F1 of compensation battery of lens group G1: F1/F3 is more than or equal to-0.71 and less than or equal to-0.55. The optical power and the focal length range of the compensation and zooming groups are reasonably distributed, so that the stability of the optical performance of the zoom lens in zooming and focusing processes is improved, the optical performance of the zoom lens is improved, and the application prospect is wider.

To sum up, the utility model discloses zoom lens zooms or the zoom in-process at the full focus within range, and the response speed of focusing is fast, can realize about 2.5 times zoom than, satisfies the confocal performance of visible light and infrared light of full focus within range simultaneously to realize the biggest light ring 1.05 at the zoom in-process. The zoom lens has a miniaturized design.

The zoom lens of the present invention is specifically described below with seven embodiments in conjunction with the drawings and tables. In each of the following embodiments, the present invention records the stop STO as one surface, records the image plane IMA as one surface, and records each cemented surface of the cemented lens as one surface.

The parameters of each example specifically satisfying the above conditional expressions are shown in table 1 below:

conditional formula (II)	Example one	Example two	EXAMPLE III	Example four
					0.54≤T1/T2≤1.62	1.494	1.240	0.966	0.937
-0.71≤F1/F3≤-0.55	-0.689	-0.647	-0.649	-0.628
					1.08≤f6/F3≤1.90	1.544	1.649	1.587	1.810
0.99≤f9/F3≤4.48	1.055	1.237	1.224	4.472

Conditional formula (II)	EXAMPLE five	Example six	EXAMPLE seven
				0.54≤T1/T2≤1.62	0.965	0.665	0.694
-0.71≤F1/F3≤-0.55	-0.642	-0.571	-0.588
				1.08≤f6/F3≤1.90	1.242	1.275	1.175
0.99≤f9/F3≤4.48	1.310	1.400	1.311

TABLE 1

In an embodiment of the present invention, the plastic aspheric lens of the zoom lens satisfies the following formula:

in the above formula, z is the axial distance from the curved surface to the vertex at the position where the height perpendicular to the optical axis is y along the optical axis direction; c represents the curvature at the apex of the aspherical surface; k is a conic coefficient; a. The ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ The values of the aspheric coefficients represent fourth, sixth, eighth, tenth, twelfth, fourteenth and sixteenth orders.

Example one

The parameters of the zoom lens of the present embodiment are as follows:

wide-angle end focal length Fw =6.41mm; tele end focus Ft =16.04mm.

Table 2 lists relevant parameters of each lens in the zoom lens of the present embodiment, including: surface type, radius of curvature, thickness, refractive index of the material, and abbe number.

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TABLE 2

Table 3 lists aspherical coefficients of the respective aspherical lenses of the zoom lens of the present embodiment, including: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface ₄ Sixth order aspherical surface coefficient A ₆ Eighth order aspheric surface coefficient A ₈ Ten-order aspheric surface coefficient A ₁₀ Twelve-order aspheric surface coefficient A ₁₂ Fourteen-order aspheric surface coefficient A ₁₄ And a sixteen-order aspheric coefficient A ₁₆ 。

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TABLE 3

Table 4 lists the variable interval values between the lens groups when the zoom lens of the present embodiment changes from the wide angle end to the telephoto end.

	Wide angle end	Long coke end
			D1	21.038	2.102
D2	14.272	1.600
			D3	2.400	15.072

TABLE 4

As shown in fig. 1 and tables 1 to 4, in the zoom lens of this embodiment, in the zooming or zooming process in the full focal length range, the focusing response speed is fast, the zoom ratio of about 2.5 times can be realized, the confocal performance of the visible light and the infrared light in the full focal length range is satisfied, and the maximum aperture of 1.05 is realized in the zooming process. The zoom lens has a miniaturized design.

Example two

The parameters of the zoom lens of the present embodiment are as follows:

wide-angle end focal length Fw =6.20mm; tele end focus Ft =15.52mm.

Table 5 lists relevant parameters of each lens in the zoom lens of the present embodiment, including: surface type, radius of curvature, thickness, refractive index of the material, and abbe number.

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TABLE 5

Table 6 lists aspherical coefficients of respective aspherical lenses of the zoom lens of the present embodiment, including: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface ₄ Sixth order aspherical surface coefficient A ₆ Eighth order aspherical surface coefficient A ₈ Ten-order aspheric surface coefficient A ₁₀ Twelve-order aspheric surface coefficient A ₁₂ Fourteen-order aspheric surface coefficient A ₁₄ And a sixteen-order aspheric coefficient A ₁₆ 。

TABLE 6

Table 7 lists the variable interval values between the lens groups when the zoom lens of the present embodiment changes from the wide angle end to the telephoto end.

	Wide angle end	Long coke end
			D1	18.057	2.216
D2	14.380	1.600
			D3	2.200	14.980

TABLE 7

As shown in fig. 2 and tables 1 and 5 to 7, in the zoom lens of this embodiment, in the zooming or magnification-varying process in the full focal length range, the focusing response speed is fast, the magnification-varying ratio of about 2.5 times can be realized, the confocal performance of visible light and infrared light in the full focal length range is satisfied, and the maximum aperture is 1.05 in the magnification-varying process. The zoom lens has a miniaturized design.

EXAMPLE III

The parameters of the zoom lens of the present embodiment are as follows:

wide-angle end focal length Fw =6.65mm; tele end focus Ft =16.65mm.

Table 8 lists relevant parameters of each lens in the zoom lens of the present embodiment, including: surface type, radius of curvature, thickness, refractive index of the material, and abbe number.

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TABLE 8

Table 9 lists aspherical coefficients of respective aspherical lenses of the zoom lens of the present embodiment, including: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface ₄ Sixth order aspherical surface coefficient A ₆ Eighth order aspheric surface coefficient A ₈ Ten-order aspheric surface coefficient A ₁₀ Twelve-order aspheric surface coefficient A ₁₂ Fourteen-order aspheric surface coefficient A ₁₄ And a sixteen-order aspheric coefficient A ₁₆ 。

TABLE 9

Table 10 lists the variable interval values between the lens groups when the zoom lens of the present embodiment is changed from the wide angle end to the telephoto end.

	Wide angle end	Long coke end
			D1	15.853	2.100
D2	15.842	1.600
			D3	2.200	16.442

Watch 10

As shown in fig. 3 and tables 1, 8 to 10, the zoom lens of this embodiment has a fast focusing response speed in the zooming or zooming process within the full focal length range, can realize a zoom ratio of about 2.5 times, and simultaneously satisfies the confocal performance of visible light and infrared light within the full focal length range, and realizes a maximum aperture of 1.05 in the zooming process. The zoom lens has a miniaturized design.

Example four

The parameters of the zoom lens of the present embodiment are as follows:

wide-angle end focal length Fw =6.85mm; tele end focus Ft =17.14mm.

Table 11 lists relevant parameters of each lens in the zoom lens of the present embodiment, including: surface type, radius of curvature, thickness, refractive index of the material, and abbe number.

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TABLE 11

Table 12 lists aspherical surface coefficients of respective aspherical lenses of the zoom lens of the present embodiment, including: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface ₄ Sixth order aspherical surface coefficient A ₆ Eighth order aspheric surface coefficient A ₈ Ten-order aspheric surface coefficient A ₁₀ Twelve-order aspheric surface coefficient A ₁₂ Fourteen-order aspheric surface coefficient A ₁₄ And a sixteen-order aspheric coefficient A ₁₆ 。

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TABLE 12

Table 13 lists the variable interval values between the lens groups when the zoom lens of the present embodiment changes from the wide angle end to the telephoto end.

	Wide angle end	Long coke end
			D1	15.522	2.100
D2	15.926	1.600
			D3	2.200	16.526

Watch 13

As shown in fig. 4 and tables 1 and 11 to 13, in the zoom lens of this embodiment, in the zooming or magnification varying process in the full focal length range, the focusing response speed is fast, the magnification varying ratio of about 2.5 times can be realized, the confocal performance of visible light and infrared light in the full focal length range is satisfied, and the maximum aperture of 1.05 is realized in the magnification varying process. The zoom lens has a miniaturized design.

EXAMPLE five

The parameters of the zoom lens of the present embodiment are as follows:

wide-angle end focal length Fw =6.57mm; tele end focus Ft =16.45mm.

Table 14 lists relevant parameters of each lens in the zoom lens of the present embodiment, including: surface type, radius of curvature, thickness, refractive index of the material, and abbe number.

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TABLE 14

Table 15 lists aspherical coefficients of respective aspherical lenses of the zoom lens of the present embodiment, including: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface ₄ Sixth order aspherical surface coefficient A ₆ Eighth order aspheric surface coefficient A ₈ Ten-order aspheric surface coefficient A ₁₀ Twelve-order aspheric surface coefficient A ₁₂ Fourteen-order aspheric surface coefficient A ₁₄ And a sixteen-order aspheric coefficient A ₁₆ 。

Watch 15

Table 16 lists the variable interval values between the lens groups when the zoom lens of the present embodiment changes from the wide angle end to the telephoto end.

	Wide angle end	Long coke end
			D1	15.524	2.100
D2	15.507	1.600
			D3	2.200	16.107

TABLE 16

As shown in fig. 5, and tables 1, 14 to 16, the zoom lens of this embodiment has a fast focusing response speed in the zooming or magnification varying process within the full focal length range, can realize a magnification varying ratio of about 2.5 times, satisfies the confocal performance of visible light and infrared light within the full focal length range, and realizes a maximum aperture of 1.05 in the magnification varying process. The zoom lens has a miniaturized design.

EXAMPLE six

The parameters of the zoom lens of the present embodiment are as follows:

wide-angle end focal length Fw =6.60mm; tele end focus Ft =16.51mm.

Table 17 lists relevant parameters of each lens in the zoom lens of the present embodiment, including: surface type, radius of curvature, thickness, refractive index of the material, and abbe number.

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TABLE 17

Table 18 lists aspherical coefficients of respective aspherical lenses of the zoom lens of the present embodiment, including: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface ₄ Sixth order aspherical surface coefficient A ₆ Eighth order aspheric surface coefficient A ₈ Ten-order aspheric surface coefficient A ₁₀ Twelve-order aspheric surface coefficient A ₁₂ Fourteen-order aspheric surface coefficient A ₁₄ And a sixteen-order aspheric coefficient A ₁₆ 。

Watch 18

Table 19 lists the variable interval values between the lens groups when the zoom lens of the present embodiment changes from the wide angle end to the telephoto end.

Watch 19

As shown in fig. 6 and tables 1, 17 to 19, the zoom lens of this embodiment has a fast focusing response speed in zooming or zooming process within the full focal length range, can realize a zoom ratio of about 2.5 times, and simultaneously satisfies the confocal performance of visible light and infrared light within the full focal length range, and realizes a maximum aperture of 1.05 in the zooming process. The zoom lens has a miniaturized design.

EXAMPLE seven

The parameters of the zoom lens of the present embodiment are as follows:

wide-angle end focal length Fw =6.55mm; tele end focus Ft =16.40mm.

Table 20 lists relevant parameters of each lens in the zoom lens of the present embodiment, including: surface type, radius of curvature, thickness, refractive index of the material, and abbe number.

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Watch 20

Table 21 lists aspherical coefficients of respective aspherical lenses of the zoom lens of the present embodiment, including: secondary curvature of the surfaceSurface constant K, fourth order aspheric surface coefficient A ₄ Sixth order aspherical surface coefficient A ₆ Eighth order aspheric surface coefficient A ₈ Ten-order aspheric surface coefficient A ₁₀ Twelve-order aspheric surface coefficient A ₁₂ Fourteen-order aspheric surface coefficient A ₁₄ And a sixteen-order aspheric coefficient A ₁₆ 。

TABLE 21

Table 22 lists the variable interval values between the lens groups when the zoom lens of the present embodiment changes from the wide angle end to the telephoto end.

	Wide angle end	Long coke end
			D1	12.830	2.100
D2	17.060	1.600
			D3	2.300	17.760

TABLE 22

As shown in fig. 7, and tables 1, 20 to 22, the zoom lens of this embodiment has a fast focusing response speed in the zooming or magnification varying process within the full focal length range, can realize a magnification varying ratio of about 2.5 times, satisfies the confocal performance of visible light and infrared light within the full focal length range, and realizes a maximum aperture of 1.05 in the magnification varying process. The zoom lens has a miniaturized design.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. 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, in order from an object side to an image side along an optical axis: a compensation lens group (G1) with negative focal power, a first fixed lens group (G2) with positive focal power, a diaphragm (STO), a zoom lens group (G3) with positive focal power, a second fixed lens group (G4) with positive focal power, a parallel flat plate (CG) and an image surface (IMA),

the compensation lens group (G1) and the magnification-varying lens group (G3) are movable along the optical axis;

in a direction from an object side to an image side along an optical axis, the compensation lens group (G1) includes, in order: a first lens (L1), a second lens (L2), a third lens (L3), and a fourth lens (L4).

2. A zoom lens according to claim 1, wherein the first lens (L1) and the fourth lens (L4) have negative optical power.

3. The zoom lens according to claim 1, wherein, in a direction from the object side to the image side along the optical axis,

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

the second lens (L2) is a concave-convex lens, a concave-concave lens or a convex-convex lens;

the third lens (L3) is a concave-convex lens or a concave-convex lens;

the fourth lens (L4) has a concave object-side surface.

4. A zoom lens according to claim 1, wherein the first fixed lens group (G2) includes: a fifth lens (L5).

5. A zoom lens according to claim 4, characterized in that the fifth lens (L5) has positive optical power.

6. A zoom lens according to claim 4, characterized in that the object-side surface of the fifth lens (L5) is convex in shape.

7. A zoom lens according to claim 1, wherein the variable power lens group (G3) includes, in order in a direction from the object side to the image side along the optical axis: a sixth lens (L6), a seventh lens (L7), an eighth lens (L8), and a ninth lens (L9).

8. A zoom lens according to claim 7, characterized in that the sixth lens (L6) and the ninth lens (L9) have positive optical power.

9. The zoom lens according to claim 7, wherein, in a direction from the object side to the image side along the optical axis,

the sixth lens (L6) is a convex lens;

the seventh lens (L7) is a convex-convex lens, a concave-convex lens or a concave-concave lens;

the eighth lens (L8) is a concave-concave lens, a convex-concave lens or a convex-convex lens;

the ninth lens (L9) is a convex lens or a concave-convex lens.

10. A zoom lens according to claim 7, wherein a focal length F6 of the sixth lens (L6) and a focal length F3 of the variable power lens group (G3) satisfy the following conditional expression: F6/F3 is more than or equal to 1.08 and less than or equal to 1.90.

11. A zoom lens according to claim 7, wherein a focal length F9 of the ninth lens (L9) and a focal length F3 of the variable power lens group (G3) satisfy the following conditional expression: F9/F3 is more than or equal to 0.99 and less than or equal to 4.48.

12. The zoom lens according to claim 7, wherein the variable magnification lens group (G3) further includes: a fifteenth lens (L15), the fifteenth lens (L15) being located between the first fixed lens group (G2) and the sixth lens (L6).

13. The zoom lens according to claim 12, wherein the fifteenth lens (L15) is a convex-concave lens or a convex-convex lens in a direction from the object side to the image side along the optical axis.

14. A zoom lens according to claim 1, wherein the second fixed lens group (G4) includes, in order in a direction from the object side to the image side along the optical axis: a tenth lens (L10), an eleventh lens (L11), a twelfth lens (L12), a thirteenth lens (L13), and a fourteenth lens (L14).

15. A zoom lens according to claim 14, wherein the tenth lens (L10), the twelfth lens (L12) and the fourteenth lens (L14) have negative optical power, and the eleventh lens (L11) and the thirteenth lens (L13) have positive optical power.

16. The zoom lens according to claim 14, wherein, in a direction from the object side to the image side along the optical axis,

the tenth lens (L10) and the twelfth lens (L12) are concave-concave lenses;

the eleventh lens (L11) and the thirteenth lens (L13) are convex lenses;

the fourteenth lens (L14) is a concave-concave lens, a convex-concave lens, or a meniscus lens.

17. A zoom lens according to claim 14, wherein the second fixed lens group (G4) further comprises: a sixteenth lens (L16), the sixteenth lens (L16) being positioned between the fourteenth lens (L14) and the parallel plate (CG).

18. A zoom lens according to claim 17, characterized in that the sixteenth lens (L16) has positive optical power.

19. The zoom lens according to claim 17, wherein the sixteenth lens (L16) is a convex-concave lens or a convex-convex lens in a direction from the object side to the image side along the optical axis.

20. A zoom lens according to any one of claims 1 to 19, wherein the variable power lens group (G3) includes at least 1 cemented lens.

21. The zoom lens according to any one of claims 1 to 19, wherein the zoom lens comprises at least 2 aspheric lenses, and at least 1 glass aspheric lens.

22. A zoom lens according to any one of claims 1 to 19, wherein a moving distance T1 of the compensation lens group (G1) and a moving distance T2 of the variable magnification lens group (G3) satisfy the following conditional expression: T1/T2 is more than or equal to 0.54 and less than or equal to 1.62.

23. A zoom lens according to any one of claims 1 to 19, wherein a focal length F1 of the compensation lens group (G1) and a focal length F3 of the variable magnification lens group (G3) satisfy the following conditional expression: F1/F3 is more than or equal to-0.71 and less than or equal to-0.55.