CN111562663B

CN111562663B - Zoom lens

Info

Publication number: CN111562663B
Application number: CN202010489497.3A
Authority: CN
Inventors: 张磊; 张占军; 金永红
Original assignee: Dongguan Yutong Optical Technology Co Ltd
Current assignee: Dongguan Yutong Optical Technology Co Ltd
Priority date: 2020-06-02
Filing date: 2020-06-02
Publication date: 2021-02-23
Anticipated expiration: 2040-06-02
Also published as: CN111562663A

Abstract

The embodiment of the invention discloses a zoom lens. The zoom lens comprises a focusing group, a fixed group and a zooming group which are sequentially arranged from an object side to an image side; in the zooming process, the fixed group is fixed in position, and the zooming group and the focusing group move along the optical axis; the focal power of each group relative to the focal power of the zoom lens at the wide-angle end satisfies a certain relational expression; the focusing group comprises a first lens, a second lens and a third lens, the fixed group comprises a fourth lens, and the variable power group comprises a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens; the sixth lens and the seventh lens form a cemented lens group, and the focal power of each lens relative to the group to which the lens belongs satisfies a certain relational expression. According to the embodiment of the invention, 4 glass lenses and 5 plastic lenses can be mixed to form the zoom lens, so that the manufacturing cost of the zoom lens can be properly reduced, the visible light aberration can be better corrected while the weight is reduced, and the confocal property of visible light and infrared light can be ensured.

Description

Zoom lens

Technical Field

The embodiment of the invention relates to the technical field of optical lenses, in particular to a zoom lens.

Background

The zoom all-in-one machine has wide application in the fields of security protection such as intelligent traffic, face recognition and the like. The zoom all-in-one machine on the market is more at present, and if a better imaging effect is to be achieved, more glass spherical lenses or a plurality of glass aspheric lenses are needed to be combined. Expensive and heavy. If low cost is required, better optical effect cannot be achieved by only using the glass spherical lens or designing with one or two glass non-spherical lenses.

Disclosure of Invention

The invention provides a zoom lens, which adopts less glass spherical lenses and glass aspherical lenses to realize a high-performance zoom lens which is confocal day and night and has a diagonal angle of view of about 140-54 degrees under a 1/1.8-inch CMOS target surface.

The embodiment of the invention provides a zoom lens, which comprises a focusing group, a fixed group and a zooming group which are sequentially arranged from an object side to an image side; the zoom lens further comprises a diaphragm, and the diaphragm is arranged in the fixed group; in the zooming process, the fixed group is fixed in position, the zooming group moves along the optical axis to zoom, and the focusing group moves along the optical axis to focus;

wherein the zoom lens has an optical power at the wide-angle end of W _ F, and the focal groups, the fixed group and the variable power group have optical powers of G1_ F, G2_ F and G3_ F, respectively; the optical power of each group relative to the zoom lens at the wide-angle end satisfies:

-0.6<G1_F/W_F<-0.4；

0<G2_F/W_F<0.1；

0.3<G3_F/W_F<0.4；

the focusing group comprises a first lens, a second lens and a third lens, the fixed group comprises a fourth lens, and the variable power group comprises a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens; the adjacent surfaces of the sixth lens and the seventh lens are glued to form a gluing lens group;

wherein the focal powers of the first lens to the fifth lens are respectively L1_ F, L2_ F, L3_ F, L4_ F, L5_ F, the focal power of the cemented lens group is U _ F, and the focal powers of the lenses relative to the group satisfy the following relations:

0.7<L1_F/G1_F<1；

0.3<L2_F/G1_F<0.5；

-0.4<L3_F/G1_F<-0.2；

L4_F＝G2_F；

0.8<L5_F/G3_F<1.1；

0.1<U_F/G3_F<0.4。

optionally, the optical powers of the first to ninth lenses are negative, positive, negative, positive or negative in this order.

Optionally, the optical power L8_ F of the eighth lens and the optical power L9_ F of the ninth lens satisfy: -0.6< L8_ F/G3_ F < 0.2; -0.4< L9_ F/G3_ F < 0.3.

Optionally, the power relationship of the sixth lens and the seventh lens satisfies: -1< L6_ F/L7_ F < -0.7;

the abbe number of the first lens is L1_ vd, the abbe number of the fifth lens is L5_ vd, the abbe number of the seventh lens is L7_ vd, and the abbe numbers of the first lens, the fifth lens and the seventh lens satisfy the following conditions: l1_ vd >40, L5_ vd >70, L7_ vd > 60.

Optionally, the refractive index of the third lens is L3 — nd, and the refractive index of the third lens satisfies: l3_ nd > 1.6.

Optionally, the refractive index of the first lens is L1 — nd, and the refractive index of the first lens satisfies: l1_ nd > 1.65;

the maximum clear aperture of the first lens is S1_ DIA, the distance from the top of the front surface of the first lens to the image plane of the zoom lens at the wide-angle end is TTL _ W, and the zoom lens meets the following requirements: s1_ DIA/TTL _ W < 0.45.

Optionally, at a wide-angle end, a distance from a vertex of a rear surface of the ninth lens to an image plane of the zoom lens is BFL _ W, a distance from a vertex of a front surface of the first lens to the image plane of the first lens is TTL _ W, and the zoom lens satisfies: BFL _ W/TTL _ W > 0.1.

Optionally, the focal group moves by a distance G1_ L along the optical axis from the wide angle end to the telephoto end, the variable power group moves by a distance G3_ L along the optical axis from the wide angle end to the telephoto end, the distance from the vertex of the front surface of the first lens to the image plane of the zoom lens at the wide angle end is TTL _ W, and the focal group and the variable power group satisfy: 0.1< G1_ L/TTL _ W <0.25, 0.05< G3_ L/TTL _ W < 0.15;

the focal power of the zoom lens at the telephoto end is T _ F, and the zoom lens satisfies the following conditions: 0.43< T _ F/W _ F < 0.52.

Optionally, the diaphragm is disposed between the fourth lens and the third lens or the fifth lens;

the diameter of the diaphragm is STO _ DIA, the distance from the diaphragm to the image plane is STO _ IMA, the distance from the top point of the front surface of the first lens to the image plane of the zoom lens at the wide-angle end is TTL _ W, and the zoom lens meets the following requirements: STO _ DIA/TTL _ W >0.17, 0.5< STO _ IMA/TTL _ W < 0.6.

Optionally, if the refractive index of the second lens is L2_ nd, the refractive index of the third lens is L3_ nd, the refractive index of the fourth lens is L4_ nd, the refractive index of the eighth lens is L8_ nd, and the refractive index of the ninth lens is L9_ nd, each lens satisfies: l2_ nd <1.72, L3_ nd <1.72, L4_ nd <1.72, L8_ nd <1.72, L9_ nd < 1.72.

Optionally, when the image height of the zoom lens is 4.4mm, then the object angle FOV _ W of the zoom lens at the wide angle end and the object angle FOV _ T at the telephoto end satisfy: 130< FOV _ W <145, 50< FOV _ T < 60;

the zoom lens satisfies optical power at the wide-angle end of 0.2< W _ F < 0.25.

The zoom lens provided by the embodiment of the invention comprises a focusing group, a fixed group and a variable power group, and the optical power of the focusing group, the fixed group and the variable power group and the optical power of the zoom lens at the wide-angle end meet-0.6 < G1_ F/W _ F < -0.4, 0< G2_ F/W _ F <0.1, 0.3< G3_ F/W _ F < 0.4; simultaneously, a focusing group comprising three lenses, a fixed group comprising one lens, a variable power group comprising five lenses, and the optical powers of the lenses and the groups are set to satisfy 0.7< L1_ F/G1_ F <1, 0.3< L2_ F/G1_ F <0.5, -0.4< L3_ F/G1_ F < -0.2, L4_ F ═ G2_ F, 0.8< L5_ F/G3_ F <1.1, 0.1< U _ F/G3_ F <0.4, so that the zoom lens can be realized by moving the variable power group on the optical axis, the focusing group can compensate the aberration by moving on the optical axis, clear imaging can be realized, and the parts of the lenses can be prepared by plastic materials and the aspheric zoom lens function or compensation function of the group can be adjusted by matching the surface shape of the group or the sphere, thereby facilitating the light weight of the zoom lens, the cost is reduced. The embodiment of the invention can realize that 4 glass lenses and 5 plastic lenses are mixed to form the zoom lens, and by reasonably matching the focal power proportion of the 9 lenses and selecting proper materials, the manufacturing cost of the zoom lens can be properly reduced, the light weight is realized, the visible light aberration is better corrected, the confocal of visible light and infrared is ensured, and the high-performance zoom lens with the 1/1.8-inch CMOS target surface, the diagonal angle of view of 140-54 degrees and the day and night confocal is realized.

Drawings

Fig. 1 is a schematic structural diagram of a zoom lens according to an embodiment of the present invention;

FIG. 2 is a wide-angle end spherical aberration diagram of the zoom lens shown in FIG. 1;

FIG. 3 is a telephoto end spherical aberration plot of the zoom lens shown in FIG. 1;

FIG. 4 is a graph of curvature of field and distortion at the wide-angle end of the zoom lens shown in FIG. 1;

FIG. 5 is a graph of field curvature and distortion at the tele end of the zoom lens of FIG. 1;

FIG. 6 is a vertical axis chromatic aberration plot at the wide-angle end of the zoom lens shown in FIG. 1;

FIG. 7 is a graph of vertical axis chromatic aberration at the tele end of the zoom lens of FIG. 1;

FIG. 8 is a chromatic shift curve diagram at the wide-angle end of the zoom lens shown in FIG. 1;

FIG. 9 is a color focus shift graph of the tele end of the zoom lens of FIG. 1;

FIG. 10 is a schematic structural diagram of another zoom lens system according to an embodiment of the present invention;

FIG. 11 is a wide-angle end spherical aberration diagram of the zoom lens shown in FIG. 10;

FIG. 12 is a telephoto end spherical aberration graph of the zoom lens shown in FIG. 10;

FIG. 13 is a graph of curvature of field and distortion at the wide-angle end of the zoom lens shown in FIG. 10;

FIG. 14 is a graph of curvature of field and distortion at the telephoto end of the zoom lens shown in FIG. 10;

FIG. 15 is a vertical axis chromatic aberration plot at the wide-angle end of the zoom lens shown in FIG. 10;

FIG. 16 is a vertical axis chromatic aberration plot of the tele end of the zoom lens of FIG. 10;

FIG. 17 is a chromatic shift curve diagram at the wide-angle end of the zoom lens shown in FIG. 10;

FIG. 18 is a chromatic shift plot of the tele end of the zoom lens shown in FIG. 10;

FIG. 19 is a schematic structural diagram of a zoom lens system according to an embodiment of the present invention;

FIG. 20 is a wide-angle end spherical aberration diagram of the zoom lens shown in FIG. 19;

FIG. 21 is a telephoto end spherical aberration graph of the zoom lens shown in FIG. 19;

FIG. 22 is a graph of curvature of field and distortion at the wide-angle end of the zoom lens shown in FIG. 19;

FIG. 23 is a graph of curvature of field and distortion at the tele end of the zoom lens of FIG. 19;

FIG. 24 is a vertical axis chromatic aberration plot at the wide-angle end of the zoom lens shown in FIG. 19;

FIG. 25 is a graph of vertical axis chromatic aberration at the tele end of the zoom lens of FIG. 19;

FIG. 26 is a chromatic shift curve diagram at the wide-angle end of the zoom lens shown in FIG. 19;

FIG. 27 is a chromatic shift curve diagram of the telephoto end of the zoom lens shown in FIG. 19.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a schematic structural diagram of a zoom lens according to an embodiment of the present invention, and referring to fig. 1, the zoom lens includes a focusing group 100, a fixed group 200, and a zoom group 300, which are sequentially arranged from an object side to an image side; the zoom lens further includes a diaphragm 400, the diaphragm 400 being disposed in the fixed group 200; in the zooming process, the fixed group 200 is fixed, the zooming group 300 moves along the optical axis to zoom, and the focusing group 100 moves along the optical axis to focus;

wherein, the focal power of the zoom lens at the wide-angle end is W _ F, and the focal powers of the focusing group 100, the fixed group 200 and the variable power group 300 are G1_ F, G2_ F and G3_ F, respectively; the optical power of each group relative to the zoom lens at the wide-angle end satisfies: -0.6< G1_ F/W _ F < -0.4, 0< G2_ F/W _ F <0.1, 0.3< G3_ F/W _ F < 0.4;

the focusing group 100 includes a first lens 1, a second lens 2 and a third lens 3, the fixed group 200 includes a fourth lens 4, and the variable power group 300 includes a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8 and a ninth lens 9; the adjacent surfaces of the sixth lens element 6 and the seventh lens element 7 are cemented to form a cemented lens group 310; the focal powers of the first lens 1 to the fifth lens 5 are respectively L1_ F, L2_ F, L3_ F, L4_ F, L5_ F, the focal power of the cemented lens group is U _ F, and the focal powers of the lenses relative to the group satisfy the following relations: 0.7< L1_ F/G1_ F <1, 0.3< L2_ F/G1_ F <0.5, -0.4< L3_ F/G1_ F < -0.2, L4_ F ═ G2_ F, 0.8< L5_ F/G3_ F <1.1, 0.1< U _ F/G3_ F < 0.4.

Therein, it is understood that the optical power is equal to the difference between the image-side and object-side convergence, which characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal power is, the stronger the bending ability to the light ray is, and the smaller the absolute value of the focal power is, the weaker the bending ability to the light ray is. When the focal power is positive, the refraction of the light is convergent; when the focal power is negative, the refraction of the light is divergent. The optical power may be suitable for characterizing a certain refractive surface of a lens (i.e. a surface of a lens), may be suitable for characterizing a certain lens or lens group, or may be suitable for characterizing a system (i.e. a group or lens group) composed of a plurality of lenses. In this embodiment, the focusing group 100, the fixed group 200 and the zoom group 300 may be disposed in a lens barrel, the fixed group 200 is fixed in position in the lens barrel, and the focusing group 100 and the zoom group 300 may reciprocate along the optical axis in the lens barrel. The zoom group 300 is used for adjusting the focal length of the lens to change the focal length of the zoom lens, and the focus group 100 is used for compensating for the aberration and the like caused by the movement of the zoom group 300. It is understood that, in the process of zooming by moving the corresponding group, the zoom lens is located at the wide-angle end when the focal length is shortest, and located at the telephoto end when the focal length is longest, and the zoom lens has different focal lengths and powers and also different lengths or forms at the wide-angle end and the telephoto end. By setting the optical powers of the focusing group 100, the fixed group 200 and the variable power group 300 and the optical power of the zoom lens at the wide angle end to satisfy: -0.6< G1_ F/W _ F < -0.4, 0< G2_ F/W _ F <0.1, 0.3< G3_ F/W _ F <0.4, so that the focal powers of the zoom group 100, the fixed group 200 and the zoom group 300 can be matched with each other, and the zoom group 100 can compensate the aberration caused during the zooming movement of the zoom group 300, that is, by synchronously moving the zoom group 300 and the zoom group 100, the zooming function can be realized, and the clarity of the image in different focal length states can be ensured.

In addition, the focusing group 100 includes three lenses, the fixed group 200 includes one lens, and the zoom group 300 includes six lenses, and each lens can be indirectly supported by a mylar sheet or a spacer. And the focal power of each lens and the group satisfies the following conditions: 0.7< L1_ F/G1_ F <1, 0.3< L2_ F/G1_ F <0.5, -0.4< L3_ F/G1_ F < -0.2, L4_ F ═ G2_ F, 0.8< L5_ F/G3_ F <1.1, 0.1< U _ F/G3_ F <0.4, on the one hand, the lens is used for limiting the action of each lens in the group, the mutual matching of each lens is ensured, and zooming and clear imaging are realized; on the other hand, on the basis of ensuring that the partial lenses have the limited optical power, the plastic material can be adopted for preparation, and the aspheric surface or the spherical surface shape is adopted to adjust the zooming function or the compensation function of the group, so that the light weight and the cost reduction of the lenses in the zoom lens are facilitated.

On the basis of the above embodiment, with the refractive index of the second lens 2 being L2_ nd, the refractive index of the third lens 3 being L3_ nd, the refractive index of the fourth lens 4 being L4_ nd, the refractive index of the eighth lens 8 being L8_ nd, and the refractive index of the ninth lens 9 being L9_ nd, alternatively, the respective lenses may be set to satisfy: l2_ nd <1.72, L3_ nd <1.72, L4_ nd <1.72, L8_ nd <1.72, L9_ nd < 1.72.

The refractive index of the lens is set to be lower than 1.72, and the material of the lens is limited to be plastic material. Specifically, the first lens 1, the sixth lens 6 and the seventh lens 7 may be all glass spherical lenses; the fifth lens 5 is a glass aspheric lens; the second lens 2, the third lens 3, the fourth lens 4, the eighth lens 8, and the ninth lens 9 are all plastic aspherical lenses. At this time, the plastic lenses with the refractive index lower than 1.72 are adopted for the partial lenses in the zoom lens, including the second lens 2, the third lens 3, the fourth lens 4, the eighth lens 8 and the ninth lens 9, so that the weight of the zoom lens can be reduced, the manufacturing difficulty of the lenses can be reduced, and the cost can be reduced. Moreover, the plastic lens adopts an aspheric lens, so that aberration formed in imaging can be better corrected. Further, the shape of each lens can be designed according to actual conditions and requirements. Alternatively, the first lens 1 may be a concave-convex or plano-concave or biconcave glass spherical negative lens, the second lens 2 may be a biconcave plastic aspheric negative lens, the third lens 3 may be a concave-convex or plano-convex or biconvex plastic aspheric positive lens, the fourth lens 4 may be a concave-convex plastic aspheric positive lens, the fifth lens 5 may be a biconvex glass aspheric lens, and the seventh lens 7 may be a biconvex glass spherical lens. The eighth lens 8 may be a plastic aspheric negative lens, and the ninth lens 9 may be a plastic aspheric positive lens. Alternatively, the power L8_ F of the eighth lens 8 and the power L9_ F of the ninth lens 9 may be set to satisfy-0.6 < L8_ F/G3_ F < 0.2; -0.4< L9_ F/G3_ F < 0.3.

In particular, in order to ensure that the zoom lens has enough variable times and can be focused to realize clear imaging. Let the focal group move by a distance G1_ L along the optical axis from the wide angle end to the telephoto end, the zoom group move by a distance G3_ L along the optical axis from the wide angle end to the telephoto end, the distance from the vertex of the front surface of the first lens 1 to the image plane of the zoom lens at the wide angle end is TTL _ W, and the optical power of the zoom lens at the telephoto end is T _ F, the focal group 100 and the zoom group 300 may be arranged to satisfy: 0.1< G1_ L/TTL _ W <0.25, 0.05< G3_ L/TTL _ W < 0.15; the zoom lens satisfies: 0.43< T _ F/W _ F < 0.52.

Further, in order to correct well the chromatic shift of infrared light of 850nm wavelength with respect to visible light, alternatively, on the basis of the above-described embodiment, the power relationship of the sixth lens 6 and the seventh lens 7 may be set so as to satisfy: -1< L6_ F/L7_ F < -0.7; let the abbe number of the first lens 1 be L1_ vd, the abbe number of the fifth lens 5 be L5_ vd, the abbe number of the seventh lens be L7_ vd, and the abbe numbers of the first lens 1, the fifth lens 5, and the seventh lens 7 satisfy: l1_ vd >40, L5_ vd >70, L7_ vd > 60.

The lower limit values of the abbe numbers of the first lens 1, the fifth lens 5 and the seventh lens 7 are respectively limited, so that the dispersion capability of the lenses can be limited, and the dispersion of light rays with different wavelengths passing through the lenses is ensured to be low, so that the chromatic focal shift of infrared light with a longer wavelength of 850nm relative to visible light is effectively corrected. Meanwhile, the power ratio relation between the sixth lens 6 and the seventh lens 7 is limited to-1 to-0.7, the power distribution inside the cemented lens group 310 is substantially limited, the axial chromatic aberration correction capability of the cemented lens group 310 can be ensured, and the chromatic aberration shift of infrared light relative to visible light can be reduced on the basis of limiting the abbe number of the seventh lens 7 to be more than 60.

On the basis of the above embodiments, in order to improve the optical effect of the zoom lens and improve the assembling quality of the zoom lens, it is necessary to configure the focusing group 100 reasonably. Alternatively, the refractive index of the third lens 3 may be set to L3 — nd, the refractive index of the third lens satisfying: l3_ nd > 1.6.

The optical eccentricity refers to the deviation of the optical center of each element in the system relative to an ideal optical axis, the optical system eccentricity has a direct influence on the image quality of the optical system, strict requirements are required for high-quality zoom lenses, and meanwhile, the refractive index of the lens reflects the refractive power of the lens on light. As can be understood by those skilled in the art, the refractive index of the third lens element 3 in the focusing group 100 is properly increased, so that the light deflection degree of the light at the position can be reduced to a certain extent, and the sensitivity of the decentering of the lens assembly in the focusing group can be effectively reduced, which is beneficial to improving the yield of the zoom lens.

Meanwhile, in order to avoid an excessively large lens aperture of the zoom lens, for the first lens 1 in the focusing group 100, let the refractive index of the first lens 1 be L1_ nd, the maximum clear aperture of the first lens be S1_ DIA, and the distance from the front surface vertex of the first lens 1 to the image plane at the wide-angle end of the zoom lens be TTL _ W. The refractive index of the first lens 1 may be set to satisfy: l1_ nd > 1.65; the zoom lens satisfies: s1_ DIA/TTL _ W < 0.45.

In addition, it should be noted that the zoom lens images on an imaging sensor disposed on a focal plane along an optical axis direction, and a flat filter is further disposed at a middle position of the zoom lens to filter light, so as to ensure an imaging effect. In order to ensure that the zoom lens has enough space for installing an imaging sensor and a flat filter, the distance from the vertex of the rear surface of the last lens to the image plane of the zoom lens at the wide-angle end is BFL _ W, the distance from the vertex of the front surface of the first lens to the image plane of the first lens is TTL _ W, the zoom lens can be set to satisfy the following conditions: BFL _ W/TTL _ W > 0.1. At this time, the rear surface of the zoom lens may have a sufficient distance and space to mount other optical imaging elements, contributing to improvement of convenience of assembly, facilitating the manufacture of the zoom lens.

On the basis of the above-described embodiment, optionally, in order to ensure that the clear brightness of the zoom lens is sufficiently large while the lens size of the magnification-varying group is not too large, the stop 400 may be disposed between the fourth lens 4 and the third lens 3 or the fifth lens 5. Further, let the diameter of the stop 400 be STO _ DIA, the distance from the stop to the image plane be STO _ IMA, and the distance from the vertex of the front surface of the first lens 1 to the image plane at the wide-angle end be TTL _ W, the zoom lens may be configured to satisfy: STO _ DIA/TTL _ W >0.17, 0.5< STO _ IMA/TTL _ W < 0.6.

Further alternatively, in order to make the zoom lens have a large angle of view, it may be set that when the image height of the zoom lens is 4.4mm, the object angle of view FOV _ W of the zoom lens at the wide angle end and the object angle of view FOV _ T at the telephoto end satisfy: 130< FOV _ W <145, 50< FOV _ T <60, while the power of the zoom lens at the wide-angle end may be set to satisfy 0.2< W _ F < 0.25.

The embodiment of the invention adopts the glass-plastic mixed optical structure, the plastic lens is easy to process, and the glass lens and the plastic aspheric lens can perform better aberration correction, so that the lens preparation difficulty is reduced, the cost is reduced, the resolution is improved, and the confocal of visible light and infrared light is realized. The zoom lens described above is explained below in three specific embodiments.

In embodiment 1, as shown in fig. 1, the zoom lens includes a focusing group 100, a fixed group 200, and a variable power group 300, which are arranged in order from an object side to an image side; the zoom lens further includes a diaphragm 400, the diaphragm 400 being disposed in the fixed group 200; in the zooming process, the fixed group 200 is fixed, the zooming group 300 moves along the optical axis to zoom, and the focusing group 100 moves along the optical axis to focus;

the focusing group 100 includes a first lens 1, a second lens 2 and a third lens 3, the fixed group 200 includes a fourth lens 4, and the variable power group 300 includes a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8 and a ninth lens 9; the adjacent surfaces of the sixth lens element 6 and the seventh lens element 7 are cemented to form a cemented lens group 310; the focal powers of the first lens 1 to the ninth lens 9 are respectively L1_ F, L2_ F, L3_ F, L4_ F, L5_ F, L6_ F, L7_ F, L8_ F, L9_ F, the focal power of the cemented lens group is U _ F, and the focal powers of the lenses relative to the group satisfy the following relations: 0.7< L1_ F/G1_ F <1, 0.3< L2_ F/G1_ F <0.5, -0.4< L3_ F/G1_ F < -0.2, L4_ F ═ G2_ F, 0.8< L5_ F/G3_ F <1.1, 0.1< U _ F/G3_ F <0.4, -0.6< L8_ F/G3_ F <0.2, -0.4< L9_ F/G3_ F < 0.3.

In example 1, the respective design values of the first lens 1 to the ninth lens 9 are shown in table 1 below.

Table 1 shows a design value of the zoom lens

The surface numbers in table 1 are numbered according to the order of the surfaces of the respective lenses, where "1" represents the front surface of the first lens, "2" represents the rear surface of the first lens, and so on; wherein the number of the surface is 9 and the STO of the surface shape is an aperture stop. The curvature radius represents the bending degree of the lens surface, a positive value represents that the surface is bent to the image surface side, and a negative value represents that the surface is bent to the object surface side, wherein 'INF' represents that the curvature radius is infinite and represents that the surface is a plane; the thickness represents the central axial distance from the current surface to the next surface, the refractive index represents the deflection capability of the material between the current surface and the next surface to light, the blank space represents that the current position is air, and the refractive index is 1; the abbe number represents the dispersion characteristic of the material between the current surface and the next surface to light, and the blank space represents that the current position is air; the K value represents the magnitude of the best fitting conic coefficient for the aspheric surface.

The aspheric conic coefficients can be defined by the following aspheric equation, but are not limited to the following representation:

wherein Z is the axial rise of the aspheric surface in the Z direction; r is the distance from a point on the aspheric surface to the optical axis; c is the curvature of the fitting sphere, and the numerical value is the reciprocal of the curvature radius; k is a fitting cone coefficient; A-F are coefficients of 4 th, 6 th, 8 th, 10 th, 12 th and 14 th order terms of the aspheric polynomial.

The aspheric surface type parameters in this example 1 are shown in table 2:

table 2 shows a design value of aspheric coefficients in the zoom lens

In this embodiment 1, the zoom interval parameters of the zoom lens at the wide angle end and the telephoto end are shown in table 3: table 3 shows a design value of a zoom interval between a wide angle end and a telephoto end in the zoom lens

	Wide angle end	Long coke end
			Zoom interval 1(mm)	8.665	0.985
Zoom interval 2(mm)	6.534	0.842
			Zoom interval 3(mm)	5.234	10.926

In this embodiment 1, each corresponding parameter in the zoom lens is shown in table 4:

table 4 shows design values of respective corresponding parameters in the zoom lens

As can be seen from table 4, in the zoom lens provided in this embodiment 1, the focal power of the focusing group 100 is negative, the focal power of the fixed group 200 is positive, the focal power of the zoom group 300 is positive, the focal power of the cemented lens group 310 is positive, the first lens 1 is a glass spherical negative lens, the second lens 2 is a plastic aspheric negative lens, the third lens 3 is a plastic aspheric positive lens, the fourth lens 4 is a plastic aspheric positive lens, the fifth lens 5 is a glass aspheric positive lens, the sixth lens 6 is a glass spherical negative lens, the seventh lens 7 is a glass spherical positive lens, the eighth lens 8 is a plastic aspheric negative lens, and the ninth lens 9 is a plastic aspheric positive lens.

Fig. 2 is a wide-angle end spherical aberration graph of the zoom lens shown in fig. 1, fig. 3 is a telephoto end spherical aberration graph of the zoom lens shown in fig. 1, fig. 4 is a field curvature and distortion graph at the wide-angle end of the zoom lens shown in fig. 1, fig. 5 is a field curvature and distortion graph at the telephoto end of the zoom lens shown in fig. 1, fig. 6 is a vertical axis chromatic aberration graph at the wide-angle end of the zoom lens shown in fig. 1, fig. 7 is a vertical axis chromatic aberration graph at the telephoto end of the zoom lens shown in fig. 1, fig. 8 is a chromatic focus shift graph at the wide-angle end of the zoom lens shown in fig. 1, and fig. 9 is a chromatic focus shift graph. As shown in fig. 2 and 3, the zoom lens provided in embodiment 1 obtains better correction of both spherical aberration and on-axis chromatic aberration at the wide angle end and telephoto end, respectively; as shown in fig. 4 and 5, the zoom lens provided in embodiment 1 obtains better correction of curvature of field and astigmatism at the wide angle end and the telephoto end, respectively; as shown in fig. 6 and 7, the zoom lens provided in embodiment 1 obtains good correction of vertical axis chromatic aberration at both the wide angle end and the telephoto end, respectively; as can be seen from fig. 8 and 9, the zoom lens provided in embodiment 1 has a good correction of the focal shift of light having a wavelength of 850nm with respect to visible light at the wide angle end and the telephoto end, respectively. As can be seen from the above, the zoom lens provided in embodiment 1 realizes correction of various aberrations, and ensures imaging quality at the wide-angle end and the telephoto end, that is, the zoom lens provided in embodiment 1 has a good imaging effect during zooming.

It should be noted that, as shown in fig. 2 and fig. 3, the wavelength ranges in the spherical aberration curves provided by the embodiments of the present invention are all 0.436 to 0.850 μm; as shown in fig. 4 and 5, in the field curvature and distortion curve provided by the embodiment of the present invention, the maximum fields of view are 68.530 ° and 27.148 °, respectively; as shown in fig. 6 and 7, 0.5876 μm is used as the reference wavelength in the vertical axis chromatic aberration curves provided by the embodiments of the present invention.

In embodiment 2, fig. 10 is a schematic structural diagram of another zoom lens according to an embodiment of the present invention, and referring to fig. 10, the zoom lens includes a focusing group 100, a fixed group 200, and a zoom group 300, which are sequentially arranged from an object side to an image side; the zoom lens further includes a diaphragm 400, the diaphragm 400 being disposed in the fixed group 200; in the zooming process, the fixed group 200 is fixed, the zooming group 300 moves along the optical axis to zoom, and the focusing group 100 moves along the optical axis to focus;

In example 2, the respective design values of the first lens 1 to the ninth lens 9 are shown in table 5 below.

Table 5 shows a design value of the zoom lens

The surface numbers in table 5 are numbered according to the order of the surfaces of the respective lenses, where "1" represents the front surface of the first lens, "2" represents the rear surface of the first lens, and so on; wherein the number of the surface is 9 and the STO of the surface shape is an aperture stop. The curvature radius represents the bending degree of the lens surface, a positive value represents that the surface is bent to the image surface side, and a negative value represents that the surface is bent to the object surface side, wherein 'INF' represents that the curvature radius is infinite and represents that the surface is a plane; the thickness represents the central axial distance from the current surface to the next surface, the refractive index represents the deflection capability of the material between the current surface and the next surface to light, the blank space represents that the current position is air, and the refractive index is 1; the abbe number represents the dispersion characteristic of the material between the current surface and the next surface to light, and the blank space represents that the current position is air; the K value represents the magnitude of the best fitting conic coefficient for the aspheric surface.

The aspheric surface type parameters in this example 1 are shown in Table 6:

table 6 shows design values of aspherical coefficients in the zoom lens

In this embodiment 2, the zoom interval parameters of the zoom lens at the wide angle end and the telephoto end are shown in table 7: table 7 shows a design value of zoom interval between wide-angle end and telephoto end in the zoom lens

	Wide angle end	Long coke end
			Zoom interval 1(mm)	8.993	1.015
Zoom interval 2(mm)	6.174	0.648
			Zoom interval 3(mm)	6.377	11.903

In this embodiment 2, each corresponding parameter in the zoom lens is shown in table 8:

table 8 shows design values of respective corresponding parameters in the zoom lens

As can be seen from table 8, in the zoom lens provided in this embodiment 2, the focal power of the focusing group 100 is negative, the focal power of the fixed group 200 is positive, the focal power of the zoom group 300 is positive, the focal power of the cemented lens group 310 is positive, the first lens 1 is a glass spherical negative lens, the second lens 2 is a plastic aspheric negative lens, the third lens 3 is a plastic aspheric positive lens, the fourth lens 4 is a plastic aspheric positive lens, the fifth lens 5 is a glass aspheric positive lens, the sixth lens 6 is a glass spherical negative lens, the seventh lens 7 is a glass spherical positive lens, the eighth lens 8 is a plastic aspheric positive lens, and the ninth lens 9 is a plastic aspheric negative lens.

Fig. 11 is a wide-angle end spherical aberration graph, fig. 12 is a telephoto end spherical aberration graph, fig. 10 is a zoom lens, fig. 13 is a field curvature and distortion graph, fig. 14 is a field curvature and distortion graph, fig. 15 is a vertical axis chromatic aberration graph, fig. 16 is a vertical axis chromatic aberration graph, fig. 17 is a chromatic focal shift graph, fig. 10 is a chromatic focal shift graph, fig. 11 is a chromatic focal shift graph, fig. 10 is a zoom lens, fig. 13 is a zoom lens, fig. 15 is a zoom lens, fig. 16 is a zoom lens, fig. 17 is a zoom lens, fig. 10 is a zoom lens. As shown in fig. 11 and 12, the zoom lens provided in embodiment 2 obtains better correction of both spherical aberration and on-axis chromatic aberration at the wide angle end and telephoto end, respectively; as shown in fig. 13 and 14, the zoom lens provided in embodiment 2 obtains better correction of curvature of field and astigmatism at the wide angle end and the telephoto end, respectively; as shown in fig. 15 and 16, the zoom lens provided in embodiment 2 obtains good correction of vertical axis chromatic aberration at both the wide angle end and the telephoto end, respectively; as can be seen from fig. 17 and 18, the zoom lens provided in embodiment 2 has a good correction of the focal shift of light of 850nm wavelength with respect to visible light at the wide angle end and the telephoto end, respectively. As can be seen from the above, the zoom lens provided in embodiment 2 realizes correction of various aberrations, and ensures imaging quality at the wide-angle end and the telephoto end, that is, the zoom lens provided in embodiment 2 has a good imaging effect during zooming.

In embodiment 3, fig. 19 is a schematic structural diagram of a zoom lens according to an embodiment of the present invention, and referring to fig. 19, the zoom lens includes a focusing group 100, a fixed group 200, and a zoom group 300, which are sequentially disposed from an object side to an image side; the zoom lens further includes a diaphragm 400, the diaphragm 400 being disposed in the fixed group 200; in the zooming process, the fixed group 200 is fixed, the zooming group 300 moves along the optical axis to zoom, and the focusing group 100 moves along the optical axis to focus;

In example 3, the respective design values of the first lens 1 to the ninth lens 9 are shown in the following table 9.

Table 9 shows a design value of the zoom lens

The surface numbers in table 9 are numbered according to the surface order of the respective lenses, where "1" represents the front surface of the first lens, "2" represents the rear surface of the first lens, and so on; wherein the number of the surface is 9 and the STO of the surface shape is an aperture stop. The curvature radius represents the bending degree of the lens surface, a positive value represents that the surface is bent to the image surface side, and a negative value represents that the surface is bent to the object surface side, wherein 'INF' represents that the curvature radius is infinite and represents that the surface is a plane; the thickness represents the central axial distance from the current surface to the next surface, the refractive index represents the deflection capability of the material between the current surface and the next surface to light, the blank space represents that the current position is air, and the refractive index is 1; the abbe number represents the dispersion characteristic of the material between the current surface and the next surface to light, and the blank space represents that the current position is air; the K value represents the magnitude of the best fitting conic coefficient for the aspheric surface.

The aspheric surface type parameters in this example 1 are shown in table 10:

table 10 shows design values of aspherical coefficients in the zoom lens

In this embodiment 3, the zoom interval parameters of the zoom lens at the wide angle end and the telephoto end are shown in table 11: TABLE 11 is a design value of zoom intervals at wide angle end and telephoto end in the zoom lens

	Wide angle end	Long coke end
			Zoom interval 1(mm)	12.485	2.247
Zoom interval 2(mm)	5.958	0.901
			Zoom interval 3(mm)	6.520	11.577

In this embodiment 3, each corresponding parameter in the zoom lens is shown in table 12:

table 12 shows design values of respective corresponding parameters in the zoom lens

As can be seen from table 12, in the zoom lens provided in this embodiment 3, the focal power of the focusing group 100 is negative, the focal power of the fixed group 200 is positive, the focal power of the zoom group 300 is positive, the focal power of the cemented lens group 310 is positive, the first lens 1 is a glass spherical negative lens, the second lens 2 is a plastic aspheric negative lens, the third lens 3 is a plastic aspheric positive lens, the fourth lens 4 is a plastic aspheric positive lens, the fifth lens 5 is a glass aspheric positive lens, the sixth lens 6 is a glass spherical negative lens, the seventh lens 7 is a glass spherical positive lens, the eighth lens 8 is a plastic aspheric negative lens, and the ninth lens 9 is a plastic aspheric positive lens.

Fig. 20 is a wide-angle end spherical aberration graph of the zoom lens shown in fig. 19, fig. 21 is a telephoto end spherical aberration graph of the zoom lens shown in fig. 19, fig. 22 is a field curvature and distortion graph at the wide-angle end of the zoom lens shown in fig. 19, fig. 23 is a field curvature and distortion graph at the telephoto end of the zoom lens shown in fig. 19, fig. 24 is a vertical axis chromatic aberration graph at the wide-angle end of the zoom lens shown in fig. 19, fig. 25 is a vertical axis chromatic aberration graph at the telephoto end of the zoom lens shown in fig. 19, fig. 26 is a chromatic focus shift graph at the wide-angle end of the zoom lens shown in fig. 19, and fig. 27 is a chromatic focus shift graph. As shown in fig. 20 and 21, the zoom lens provided in embodiment 3 obtains better correction of both spherical aberration and on-axis chromatic aberration at the wide angle end and telephoto end, respectively; as shown in fig. 22 and 23, the zoom lens provided in embodiment 3 obtains better correction of curvature of field and astigmatism at the wide angle end and the telephoto end, respectively; as shown in fig. 24 and 25, the zoom lens provided in embodiment 3 obtains good correction of vertical axis chromatic aberration at both the wide angle end and the telephoto end, respectively; as can be seen from fig. 26 and 27, the zoom lens provided in embodiment 3 is better corrected for a focal shift of light of 850nm wavelength with respect to visible light at the wide angle end and the telephoto end, respectively. As can be seen from the above, the zoom lens provided in embodiment 3 realizes correction of various aberrations, and ensures imaging quality at the wide-angle end and the telephoto end, that is, the zoom lens provided in embodiment 3 has a good imaging effect during zooming.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A zoom lens is characterized by comprising a focusing group, a fixed group and a zooming group which are sequentially arranged from an object side to an image side; the zoom lens further comprises a diaphragm, and the diaphragm is arranged in the fixed group; in the zooming process, the fixed group is fixed in position, the zooming group moves along the optical axis to zoom, and the focusing group moves along the optical axis to focus;

-0.6<G1_F/W_F<-0.4；

0<G2_F/W_F<0.1；

0.3<G3_F/W_F<0.4；

0.7<L1_F/G1_F<1；

0.3<L2_F/G1_F<0.5；

-0.4<L3_F/G1_F<-0.2；

L4_F＝G2_F；

0.8<L5_F/G3_F<1.1；

0.1<U_F/G3_F<0.4。

2. the zoom lens according to claim 1, wherein optical powers of the first lens to the ninth lens are negative, positive, negative, positive or negative, or positive or negative in order.

3. The zoom lens according to claim 2, wherein an optical power L8_ F of the eighth lens and an optical power L9_ F of the ninth lens satisfy:

-0.6<L8_F/G3_F<0.2；

-0.4<L9_F/G3_F<0.3。

4. the zoom lens according to claim 1, wherein an optical power relationship of the sixth lens and the seventh lens satisfies: -1< L6_ F/L7_ F < -0.7;

5. The zoom lens according to claim 1, wherein a refractive index of the third lens is L3_ nd, and the refractive index of the third lens satisfies: l3_ nd > 1.6.

6. The zoom lens according to claim 1, wherein a refractive index of the first lens is L1_ nd, and the refractive index of the first lens satisfies: l1_ nd > 1.65;

7. The zoom lens according to claim 1, wherein at a wide-angle end, a distance from a vertex of a rear surface of the ninth lens to an image plane of the zoom lens is BFL _ W, a distance from a vertex of a front surface of the first lens to an image plane is TTL _ W, and the zoom lens satisfies: BFL _ W/TTL _ W > 0.1.

8. The zoom lens according to claim 1, wherein the focal group is moved by a distance G1_ L along the optical axis from a wide angle end to a telephoto end, the magnification-varying group is moved by a distance G3_ L along the optical axis from a wide angle end to a telephoto end, the distance from a vertex of a front surface of the first lens to an image plane of the zoom lens at a wide angle end is TTL _ W, and the focal group and the magnification-varying group satisfy: 0.1< G1_ L/TTL _ W <0.25, 0.05< G3_ L/TTL _ W < 0.15;

9. The zoom lens according to claim 1, wherein the stop is provided between the fourth lens and the third lens or the fifth lens;

10. The zoom lens according to claim 1, wherein a refractive index of the second lens is L2_ nd, a refractive index of the third lens is L3_ nd, a refractive index of the fourth lens is L4_ nd, a refractive index of the eighth lens is L8_ nd, and a refractive index of the ninth lens is L9_ nd, and then each lens satisfies: l2_ nd <1.72, L3_ nd <1.72, L4_ nd <1.72, L8_ nd <1.72, L9_ nd < 1.72.

11. The zoom lens according to claim 1, wherein when an image height of the zoom lens is 4.4mm, then an object angle of view FOV _ W at a wide angle end and an object angle of view FOV _ T at a telephoto end of the zoom lens satisfy: 130< FOV _ W <145, 50< FOV _ T < 60;