CN216248548U - Zoom lens and imaging device - Google Patents

Abstract

The utility model discloses a zoom lens and an imaging device, the zoom lens comprises a lens main body, the lens main body comprises a lens cone, a first lens group with positive focal power, a second lens group with negative focal power, a third lens group with positive focal power, a fourth lens group with positive focal power, a fifth lens group with negative focal power, a sixth lens group with positive focal power, a seventh lens group with negative focal power and a photosensitive chip, the first lens group, the second lens group, the fourth lens group, the fifth lens group and the sixth lens group are arranged in the lens cone from front to back in sequence, the first lens group, the second lens group, the fourth lens group, the fifth lens group and the sixth lens group are movably arranged along the front-back direction relative to the lens cone, through reasonable arrangement of seven lens groups and conditional limitation of the focal length of the wide-angle end of the zoom lens and the focal length ratio of each lens group, the zoom lens has the effects of small volume, large zoom, large image surface and large aperture.

Description

Zoom lens and imaging device

Technical Field

The present invention relates to the field of optical system design technologies, and in particular, to a zoom lens and an imaging device.

Background

Along with the development of society, people's safety precaution consciousness is constantly improved, and security protection monitoring industry also obtains high-speed development, and the effect of control performance is also bigger and bigger. The zoom lens has practical design and use in the last century, and with the development of lens design technology, the application occasions of the zoom lens are gradually increased. Nowadays, zoom lenses have been widely used in the fields of civil products, security monitoring, and the like. However, the zoom lens has poorer imaging quality than the common fixed focal length lens, so the use popularity of the zoom lens is not high. Moreover, most of the target surfaces of the zoom lenses on the market are small in size, so that the acquired image is low in resolution, the shooting effect is general, and the picture value is low. Most of the apertures of the zoom lenses on the market are small, so that the light transmission of the lenses is less, images obtained under a low-illumination scene are darker, and the image quality is difficult to guarantee. With the advance of high-definition and miniaturization of security protection, a lens is required to achieve higher performance and smaller size.

SUMMERY OF THE UTILITY MODEL

The utility model mainly aims to provide a zoom lens, aiming at solving the technical problems that the zoom lens in the prior art has smaller aperture, smaller image surface, large zoom and small volume and cannot coexist.

In order to achieve the above object, the present invention provides a zoom lens, comprising a lens body, a lens module, and a lens module, wherein the direction from an object side to an image side along an optical axis of the lens body is from front to back;

the lens main body comprises a lens barrel, a first lens group with positive focal power, a second lens group with negative focal power, a third lens group with positive focal power, a fourth lens group with positive focal power, a fifth lens group with negative focal power, a sixth lens group with positive focal power, a seventh lens group with negative focal power and a photosensitive chip, wherein the first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group and the sixth lens group are sequentially arranged in the lens barrel from front to back;

wherein the zoom lens satisfies the following conditions: 0.04 < fw/f1 < 0.38, and-2.15 < fw/f2 < -0.24, and 0.35 < fw/f3 < 0.04, and 0.1 < fw/f4 < 0.93, and-1.22 < fw/f5 < -0.14, and 0.15 < fw/f61.31, and-0.85 < fw/f7 < -0.09;

wherein fw is a focal length of the zoom lens at a wide-angle end, f1 is a focal length of the first lens group, f2 is a focal length of the second lens group, f3 is a focal length of the third lens group, f4 is a focal length of the fourth lens group, f5 is a focal length of the fifth lens group, f6 is a focal length of the sixth lens group, and f7 is a focal length of the seventh lens group.

Optionally, the first lens group comprises a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power and a fourth lens with positive focal power, which are arranged in sequence from front to back;

the first lens group and the first, second, third, and fourth lenses satisfy the following conditions: 0.03 < f1/f11 < 0.28, and-2.21 < f1/f12 < -0.25, and 0.11 < f1/f13 < 1.02, and 0.21 < f1/f14 < 1.91;

wherein f1 is the focal length of the first lens group, f11 is the focal length of the first lens, f12 is the focal length of the second lens, f13 is the focal length of the third lens, and f14 is the focal length of the fourth lens.

Optionally, the second lens group includes a fifth lens with negative focal power, a sixth lens with negative focal power, a seventh lens with positive focal power, and an eighth lens with negative focal power, which are sequentially arranged from front to back, where the eighth lens is an aspheric lens;

the second lens group, the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy the following conditions: 0.21 < f2/f21 < 1.91, and 0.07 < f2/f22 < 0.63, and-0.56 < f2/f23 < -0.06, and 0.05 < f2/f24 < 0.49;

wherein f2 is a focal length of the second lens group, f21 is a focal length of the fifth lens group, f22 is a focal length of the sixth lens group, f23 is a focal length of the seventh lens group, and f24 is a focal length of the eighth lens group.

Optionally, the third lens group includes a ninth lens having positive optical power, and the ninth lens is an aspheric lens.

Optionally, the fourth lens group includes a tenth lens with positive focal power, an eleventh lens with positive focal power, a twelfth lens with negative focal power, and a thirteenth lens with negative focal power, which are sequentially arranged from front to back, where the tenth lens is an aspheric lens;

the fourth lens group and the tenth, eleventh, twelfth, thirteenth lens satisfy the following relationships: 0.25 < f4/f41 < 2.21, and 0.24 < f4/f42 < 2.18, and-0.18 < f4/f43 < -1.65, and 0.01 < f4/f44 < 0.11;

wherein f4 is a focal length of the fourth lens group, f41 is a focal length of the tenth lens, f42 is a focal length of the eleventh lens, f43 is a focal length of the twelfth lens, and f44 is a focal length of the thirteenth lens.

Optionally, the fifth lens group comprises a fourteenth lens with negative focal power, a fifteenth lens with negative focal power and a sixteenth lens with negative focal power, which are arranged in sequence from front to back;

the fifth lens group and the fourteenth lens, the fifteenth lens, the sixteenth lens satisfy the following relationships: 0.19 < f5/f51 < 1.7, and 0.09 < f5/f52 < 0.82, and 0.06 < f5/f53 < 0.52;

wherein f5 is a focal length of the fifth lens group, f51 is a focal length of the fourteenth lens group, f52 is a focal length of the fifteenth lens group, and f53 is a focal length of the sixteenth lens group.

Optionally, the sixth lens group includes a seventeenth lens with negative focal power, an eighteenth lens with negative focal power, a nineteenth lens with positive focal power, and a twentieth lens with positive focal power, which are sequentially arranged from front to back, wherein the twentieth lens is an aspheric lens;

the sixth lens group and the seventeenth lens, the eighteenth lens, the nineteenth lens, and the twentieth lens satisfy the following relationships: -1.93 < f6/f61 < -0.21, and-0.16 < f6/f62 < -0.02, and 0.15 < f6/f63 < 1.37, and 0.21 < f6/f64 < 1.85;

wherein f6 is a focal length of the sixth lens group, f61 is a focal length of the seventeenth lens, f62 is a focal length of the eighteenth lens, f63 is a focal length of the nineteenth lens, and f64 is a focal length of the twentieth lens.

Optionally, the seventh lens group comprises a twenty-first lens having a negative optical power.

Optionally, the zoom lens further includes a diaphragm, and the diaphragm is located between the fourth lens group and the fifth lens group;

the zoom lens satisfies the following conditions: L/TTL is more than 0.09 and less than 0.8;

wherein, L is the distance between the diaphragm and the imaging surface of the zoom lens on the optical axis, and TTL is the total optical length of the zoom lens.

The utility model also provides an imaging device which comprises the zoom lens in the technical scheme.

In the technical solution provided by the present invention, the lens main body includes a lens barrel, and a first lens group having positive focal power, a second lens group having negative focal power, a third lens group having positive focal power, a fourth lens group having positive focal power, a fifth lens group having negative focal power, a sixth lens group having positive focal power, a seventh lens group having negative focal power, and a photosensitive chip, which are sequentially disposed in the lens barrel from front to back, wherein the second lens group, the fourth lens group, the fifth lens group, and the sixth lens group are respectively movably disposed in a front-back direction with respect to the lens barrel, at least one of the second lens group, the fourth lens group, and the fifth lens group moves along the optical axis to zoom the zoom lens, and the sixth lens group moves along the optical axis to focus the zoom lens, through reasonable arrangement of seven lens groups and conditional limitation of the ratio of the focal length of the wide-angle end of the zoom lens to the focal length of each lens group, the zoom lens has the effects of small volume, large zoom, large image plane and large aperture.

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 description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

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

fig. 2 is a schematic MTF curve of the zoom lens in fig. 1 at the wide-angle end;

fig. 3 is a schematic view of an MTF curve of the zoom lens in fig. 1 at the telephoto end.

The reference numbers illustrate:

the implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indication is involved in the embodiment of the present invention, the directional indication is only used for explaining the relative positional relationship, the motion situation, and the like between the components in a certain posture, and if the certain posture is changed, the directional indication is changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" appearing throughout includes three juxtapositions, exemplified by "A and/or B" including either A or B or both A and B. Also, the technical solutions in the embodiments may be combined with each other, but must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not be within the protection scope of the present invention.

Along with the development of society, people's safety precaution consciousness is constantly improved, and security protection monitoring industry also obtains high-speed development, and the effect of control performance is also bigger and bigger. The zoom lens has practical design and use in the last century, and with the development of lens design technology, the application occasions of the zoom lens are gradually increased. Nowadays, zoom lenses have been widely used in the fields of civil products, security monitoring, and the like. However, the zoom lens has poorer imaging quality than the common fixed focal length lens, so the use popularity of the zoom lens is not high. Moreover, most of the target surfaces of the zoom lenses on the market are small in size, so that the acquired image is low in resolution, the shooting effect is general, and the picture value is low. Most of the apertures of the zoom lenses on the market are small, so that the light transmission of the lenses is less, images obtained under a low-illumination scene are darker, and the image quality is difficult to guarantee. With the advance of high-definition and miniaturization of security protection, a lens is required to achieve higher performance and smaller size.

In view of the above, the main objective of the present invention is to provide a zoom lens and an imaging device, which aims to solve the technical problem in the prior art that the lens of the zoom lens has a small aperture, a small image plane, a large zoom and a small volume, which cannot coexist, and refer to fig. 1 to 3, which are an embodiment of the zoom lens.

First, it can be appreciated that the optical power is equal to the difference between the image-side and object-side beam convergence, which characterizes the ability of the imaging device 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 can be suitable for representing a certain refractive surface of a lens (namely, a surface of the lens), can be suitable for representing a certain lens, and can also be suitable for representing a system (namely a lens group) formed by a plurality of lenses together.

The optical axis of the zoom lens is from front to back in a direction from an object side to an image side, it can be understood that the object side faces a subject, and the light ray transmission direction is from the object side to the image side.

The zoom lens comprises a lens body, wherein the lens body comprises a lens barrel, a first lens group 1 with positive focal power, a second lens group 2 with negative focal power, a third lens group 3 with positive focal power, a fourth lens group 4 with positive focal power, a fifth lens group 5 with negative focal power, a sixth lens group 6 with positive focal power, a seventh lens group 7 with negative focal power and a photosensitive chip 9 which are arranged in the lens barrel from front to back in sequence, the second lens group 2, the fourth lens group 4, the fifth lens group 5 and the sixth lens group 6 are respectively arranged in a front-back movable manner relative to the lens barrel, at least one of the second lens group 2, the fourth lens group 4 and the fifth lens group 5 moves along the optical axis to zoom the zoom lens, and the sixth lens group 6 moves along the optical axis, so that the zoom lens is focused; wherein the zoom lens satisfies the following conditions: 0.04 < fw/f1 < 0.38, and-2.15 < fw/f2 < -0.24, and 0.35 < fw/f3 < 0.04, and 0.1 < fw/f4 < 0.93, and-1.22 < fw/f5 < -0.14, and 0.15 < fw/f61.31, and-0.85 < fw/f7 < -0.09; where fw is a focal length of the zoom lens at a wide-angle end, f1 is a focal length of the first lens group 1, f2 is a focal length of the second lens group 2, f3 is a focal length of the third lens group 3, f4 is a focal length of the fourth lens group 4, f5 is a focal length of the fifth lens group 5, f6 is a focal length of the sixth lens group 6, and f7 is a focal length of the seventh lens group 7.

Specifically, in the present embodiment, the ratio of the focal length of the zoom lens at the wide-angle end to the focal length of each lens group is specifically as follows: 8/63 for fw/f1, 68/95 for fw/f2, 3/26 for fw/f3, 30/97 for fw/f4, 15/37 for fw/f5, 38/87 for fw/f6, and 28/99 for fw/f 7.

In the technical solution provided by the present invention, at least one of the second lens group 2, the fourth lens group 4 and the fifth lens group 5 moves along the optical axis to zoom the zoom lens, the sixth lens group 6 moves along the optical axis to focus the zoom lens, and the zoom lens has the effects of small volume, large zoom, large image plane and large aperture through reasonable setting of seven lens groups and conditional restrictions on the focal length of the wide-angle end of the zoom lens and the focal length ratio of each lens group, and the long zoom stroke of the high-magnification lens is divided into the short zoom strokes of a plurality of zoom groups: the lens adopts the structure that the second lens group 2, the fourth lens group 4, the fifth lens group 5 zoom and the sixth lens group 6 focus, the zooming stroke of each group is short, certain overlapping and mutual noninterference exist, and the zooming stroke of the lens is effectively compressed.

Specifically, the first lens group 1 includes a first lens 11 having positive refractive power, a second lens 12 having negative refractive power, a third lens 13 having positive refractive power, and a fourth lens 14 having positive refractive power, which are arranged in this order from front to back; the first lens group 1, the first lens 11, the second lens 12, the third lens 13, and the fourth lens 14 satisfy the following conditions: 0.03 < f1/f11 < 0.28, and-2.21 < f1/f12 < -0.25, and 0.11 < f1/f13 < 1.02, and 0.21 < f1/f14 < 1.91; wherein f1 is the focal length of the first lens group 1, f11 is the focal length of the first lens 11, f12 is the focal length of the second lens 12, f13 is the focal length of the third lens 13, and f14 is the focal length of the fourth lens 14.

More specifically, in this embodiment, the first lens element 11 is a convex-concave lens, i.e., the object-side surface of the first lens element 11 is a convex surface, the image-side surface is a concave surface, the second lens element 12 is a convex-concave lens, i.e., the object-side surface of the second lens element 12 is a convex surface, the image-side surface is a concave surface, the third lens element 13 is a convex-concave lens, i.e., the object-side surface of the third lens element 13 is a convex surface, the image-side surface is a concave surface, the fourth lens element 14 is a convex-concave lens, i.e., the object-side surface of the fourth lens element 14 is a convex surface, the image-side surface is a concave surface, and specific ratios of the first lens group to the respective lenses are as follows: f1/f11 is 5/54, f1/f12 is- (25/34), f1/f13 is 29/85, f1/f14 is 7/11, and the focal powers of the first lens 11 to the fourth lens 14 are: 838.37, -105.54, 227.54, 121.88.

Further, the first lens 11 and the second lens 12 constitute a first cemented lens having positive optical power, and the following condition is satisfied: f1/f101 is more than 0.02 and less than 0.16; wherein f1 is the focal length of the first lens group 11, and f101 is the focal length of the first cemented lens; in this embodiment, a specific ratio of the first lens group to the first cemented lens is f1/f 101-4/77.

Specifically, the second lens group 2 includes a fifth lens 21 having a negative refractive power, a sixth lens 22 having a negative refractive power, a seventh lens 23 having a positive refractive power, and an eighth lens 24 having a negative refractive power, which are arranged in this order from front to back, wherein the eighth lens 24 is an aspherical lens; the second lens group 2, the fifth lens 21, the sixth lens 22, the seventh lens 23, and the eighth lens 24 satisfy the following conditions: 0.21 < f2/f21 < 1.91, and 0.07 < f2/f22 < 0.63, and-0.56 < f2/f23 < -0.06, and 0.05 < f2/f24 < 0.49; wherein f2 is the focal length of the second lens group 2, f21 is the focal length of the fifth lens 21, f22 is the focal length of the sixth lens 22, f23 is the focal length of the seventh lens 23, and f24 is the focal length of the eighth lens 24.

More specifically, in this embodiment, the fifth lens element 21 is a convex-concave lens element, that is, the object-side surface and the image-side surface of the fifth lens element 2121 are convex and concave, the sixth lens element 22 is a biconcave lens element, the seventh lens element 2323 is a biconvex lens element, and the eighth lens element 24 is a biconcave lens element; and, the specific ratio of the second lens group to each lens therein is as follows: f2/f21 is 7/11, f2/f22 is 5/24, f2/f23 is- (18/97), f2/f24 is 6/37, and the powers of the fifth lens 21 to the eighth transparent lens are: 21.62, -66.13, 74.16, -84.74.

Further, the sixth lens 22 and the seventh lens 23 constitute a second cemented lens having a negative power, and the following condition is satisfied: 0.03 < f2/f201 < 0.23, wherein f2 is the focal length of the second lens group 2, and f201 is the focal length of the second cemented lens, and in this embodiment, the specific ratio of the second lens group to the second cemented lens is f2/f 201-1/13.

Specifically, the third lens group 3 includes a ninth lens 31 having positive optical power, and the ninth lens 31 is an aspherical lens.

More specifically, in the present embodiment, the ninth lens 31 is a double-convex lens, and the optical power of the ninth lens 31 is 85.22.

Specifically, the fourth lens group 4 includes, in order from front to back, a tenth lens 41 having positive optical power, an eleventh lens 42 having positive optical power, a twelfth lens 43 having negative optical power, and a thirteenth lens 44 having negative optical power, in which the tenth lens 41 is an aspherical lens; the fourth lens group 4, the tenth lens 41, the eleventh lens 42, the twelfth lens 43, and the thirteenth lens 44 satisfy the following relationships: 0.25 < f4/f41 < 2.21, and 0.24 < f4/f42 < 2.18, and-0.18 < f4/f43 < -1.65, and 0.01 < f4/f44 < 0.11; where f4 is a focal length of the fourth lens group 4, f41 is a focal length of the tenth lens 41, f42 is a focal length of the eleventh lens 42, f43 is a focal length of the twelfth lens 43, and f44 is a focal length of the thirteenth lens 44.

More specifically, in the present embodiment, the tenth lens 41 is a double-convex lens, the eleventh lens 42 is a double-convex lens, the twelfth lens 43 is a double-concave lens, the thirteenth lens 44 is a double-convex lens, and specific ratios of the fourth lens group to each of the lenses are as follows: f4/f41 is 39/53, f4/f42 is 8/11, f4/f43 is- (17/31), f4/f44 is 1/28, and the powers of the tenth lens 41 to the thirteenth transparent lens are: 43.29, 43.77, -58.09, -885.87.

Further, the twelfth lens 43 and the thirteenth lens 44 constitute a third cemented lens having a negative power, and satisfy the following condition: -1.4 < f4/f401 < -0.16; where f4 is the focal length of the fourth lens group 4, and f401 is the focal length of the third cemented lens, in this embodiment, the specific ratio of the fourth lens group to the third cemented lens is f4/f401 ═ 7/15.

Specifically, the fifth lens group 5 includes a fourteenth lens 51 having a negative power, a fifteenth lens 52 having a negative power, and a sixteenth lens 53 having a negative power, which are arranged in this order from front to back; the fifth lens group 5, the fourteenth lens 51, the fifteenth lens 52, and the sixteenth lens 53 satisfy the following relationships: 0.19 < f5/f51 < 1.7, and 0.09 < f5/f52 < 0.82, and 0.06 < f5/f53 < 0.52; wherein f5 is the focal length of the fifth lens group 5, f51 is the focal length of the fourteenth lens 51, f52 is the focal length of the fifteenth lens 52, and f53 is the focal length of the sixteenth lens 53.

More specifically, in this embodiment, the fourteenth lens 51 is a biconcave lens, the fifteenth lens 52 is a meniscus lens, that is, the object-side surface of the fifteenth lens 52 is a concave surface, the image-side surface is a convex surface, the sixteenth lens 53 is a biconcave lens, and specific ratios of the fifth lens group to the lenses are as follows: 38/67 for f5/f51, 25/92 for f5/f52, 5/29 for f5/f53, wherein the powers of the fourteenth lens 51 to the sixteenth lens 53 are: -42.85, -89.43, -140.75.

Further, the fifteenth lens 52 and the sixteenth lens 53 constitute a fourth cemented lens having a negative optical power, and satisfy the following condition: 0.13 < f5/f501 < 1.19, where f5 is the focal length of the fifth lens group 5, and f501 is the focal length of the fourth cemented lens, and in this embodiment, the specific ratio of the fifth lens group to the fourth cemented lens is f5/f 501-35/88.

Specifically, the sixth lens group 6 includes a seventeenth lens 61 having a negative optical power, an eighteenth lens 62 having a negative optical power, a nineteenth lens 63 having a positive optical power, and a twentieth lens 64 having a positive optical power, which are arranged in this order from front to back, wherein the twentieth lens 64 is an aspherical lens; the sixth lens group 6, the seventeenth lens 61, the eighteenth lens 62, the nineteenth lens 63, and the twentieth lens 64 satisfy the following relationships: -1.93 < f6/f61 < -0.21, and-0.16 < f6/f62 < -0.02, and 0.15 < f6/f63 < 1.37, and 0.21 < f6/f64 < 1.85; wherein f6 is a focal length of the sixth lens group, f61 is a focal length of the seventeenth lens 61, f62 is a focal length of the eighteenth lens 62, f63 is a focal length of the nineteenth lens 63, and f64 is a focal length of the twentieth lens 64.

More specifically, in this embodiment, the seventeenth lens element 61 is a convex lens element, i.e., the object-side surface of the seventeenth lens element 61 is a plane, the image-side surface is a convex surface, the eighteenth lens element 62 is a meniscus lens element, i.e., the object-side surface of the eighteenth lens element 62 is a concave surface, and the image-side surface is a convex surface, the nineteenth lens element 63 is a biconvex lens element, the twentieth lens element 64 is a meniscus lens element, i.e., the object-side surface of the twentieth lens element 64 is a concave surface, and the image-side surface is a convex surface, and specific ratios of the sixth lens group to the respective lens elements are as follows: f6/f61 ═ 61/95, f6/f62 ═ 5/94, f6/f63 ═ 16/35, f6/f64 ═ 55/89, and the powers of the seventeenth lens 61 to the twentieth lens 64 are, in order: 35.12, -424.39, 49.32, 36.49.

Further, the seventeenth lens 61 and the eighteenth lens 62 constitute a fifth cemented lens having a negative power, and the following condition is satisfied: -0.16 < f6/f601 < -0.02, wherein f6 is the focal length of the sixth lens group 6, and f601 is the focal length of the fifth cemented lens, and in the present embodiment, the specific ratio of the sixth lens group to the fifth cemented lens is f6/f601 ═ 5/94.

Specifically, the seventh lens group 7 includes a twenty-first lens 71 having a negative optical power.

More specifically, in the present embodiment, the twenty-first lens 71 is a biconcave lens, and the optical power of the twenty-first lens 71 is-34.83.

Specifically, the zoom lens further includes a diaphragm 8, and the diaphragm 8 is located between the fourth lens group 4 and the fifth lens group 5; the zoom lens satisfies the following conditions: L/TTL is more than 0.09 and less than 0.8; wherein L is a distance between the diaphragm 8 and an imaging surface of the zoom lens on the optical axis, and TTL is a total optical length of the zoom lens. In this embodiment, L/TTL is 13/49, and the diaphragm 8 is an adjustable diaphragm 8, the adjustable diaphragm 8 can perform corresponding aperture-zooming measures with the change of the ambient light intensity, and the diaphragm 8 is used for limiting the light beam, so as to further improve the imaging quality of the zoom lens.

Specifically, the effective clear aperture of the first lens satisfies:

wherein the content of the first and second substances,

TTL is an effective clear aperture of the first lens 11, and TTL is an optical total length of the zoom lens, which is specifically the embodiment

Specifically, the zoom lens satisfies the following conditions: Δ 0.08 < Z1W-T/TTL < 0.71, and-0.49 < Z2W-T/TTL < -0.05, and-0.18 < Z3W-T/TTL < -0.02, wherein: Δ Z1W-T is a relative displacement of the front vertex of the second lens group 2 at the wide-angle end position and the telephoto end position, Δ Z2W-T is a relative displacement of the front vertex of the fourth lens group 4 at the wide-angle end position and the telephoto end position, Δ Z3W-T is a relative displacement of the front vertex of the fifth lens group 5 at the wide-angle end position and the telephoto end position, and TTL is an optical total length of the zoom lens, which is specifically Δ Z1W-T/TTL ═ 21/89, Z2W-T/TTL ═ 11/68, and Z3W-T/TTL — (2/33) in the present embodiment.

Specifically, the zoom lens further comprises an optical filter, the optical filter is located between the twenty-first lens 71 and the photosensitive chip 9, and the optical filter is used for filtering out light rays in an unnecessary waveband and stray light, so that the imaging quality is improved.

Further, the zoom lens may further include a protective glass disposed between the optical filter and the light sensing chip 9 to prevent internal elements (e.g., chips) of the zoom lens from being damaged.

Based on the above, the eighth lens element 24, the ninth lens element 31, the tenth lens element 41, and the twentieth lens element 64 are all aspheric lenses, and it can be understood that the aspheric lenses are characterized in that: the curvature is continuously changed from the lens center to the lens periphery, and the aspheric lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatic aberration, and after the aspheric lens is adopted, the aberration generated during imaging can be eliminated as much as possible, so that the imaging quality of the lens is improved.

Further, in the present embodiment, the aspherical surface shape of the aspherical lens satisfies the following condition:

in the formula, a parameter c is a curvature corresponding to a radius, r is a radial coordinate, the unit of the radial coordinate is the same as the unit of the length of the lens, k is a conical conic coefficient, when the k coefficient is less than-1, a surface curve is a hyperbolic curve, when the k coefficient is equal to-1, a parabola is formed, when the k coefficient is between-1 and 0, the curve is an ellipse, when the k coefficient is equal to 0, the curve is a circular curve, when the k coefficient is greater than 0, the curve is an oblate circle, and alpha 1 to alpha 8 respectively represent coefficients corresponding to the radial coordinates, and the shape size of front and back aspheric surfaces of the lens can be accurately set through the parameters. The requirement of light weight of the product is realized under the condition of ensuring that the lens has good picture requirements, the driving load is reduced, and great contribution is made to the reduction of the volume of the driving part.

Specifically, in the present embodiment, the parameters of the zoom lens are as shown in the following table.

TABLE 1 parameters of respective lenses of the zoom lens

In this embodiment, the even-order coefficient of each aspheric surface is shown in the following table.

TABLE 3 even-order coefficient of aspheric lens of zoom lens

The zoom lens has wide-angle end focal length EFL _ W of 9.85mm and tele end focal length EFL _ T of 303.1 mm; the wide-angle end diaphragm number Fno _ W is equal to 1.6, and the telephoto end diaphragm number Fno _ T is equal to 5.4; the wide-angle end horizontal field angle FOVH _ W is 61 °, and the telephoto end field angle FOVH _ T is 2.1 °; the optical distortion of the system belongs to (-5%, 2%); the total optical length (i.e. the distance from the central vertex of the front surface of the first lens to the image plane) TTL of the optical system is 180mm

The zoom imaging device adopts a five-group structure of positive, negative, positive, negative and positive, and the system comprises 4 glass aspheric surfaces, so that the manufacturing cost is fully reduced under the conditions of realizing large image plane, large aperture, small distortion and large magnification variation.

Although the zoom lens uses the aspheric lens, the performance of the lens is slightly influenced by temperature change through conditionally limiting the focal length of the zoom lens, the change of the back focus is very little, the performance is stable under the condition of indoor environment change, and refocusing is not needed.

In the zoom lens, as the second lens group, the fourth lens group and the fifth lens group move forwards and backwards, the focal length changes, the fourth lens group is used for a focusing function, the focal length can change at the WIDE angle end of 9.85mm and the telephoto end of 303.1mm (1/1.2, for example, a CCD (charge coupled device) of 16: 9), the shooting angle level at the WIDE angle end (WIDE) is more than 61 degrees, the optical distortion at the WIDE angle end (WIDE) and the telephoto end is within 2 percent, and the zoom lens has the effects of WIDE angle, small distortion and large magnification.

The zoom lens uses an adjustable diaphragm, FNO is up to 1.6 at a wide angle end, FNO is up to 5.4 at a telephoto end, the zoom lens has extremely high photosensitivity, and a relatively clear picture can be shot under a relatively dark environment.

The zoom lens takes the first lens group as the highest point, the distance position between the first lens group and the image plane is fixed, and the height of the zoom lens is less than 180mm (taking a 1/2.8' CCD as an example).

The zoom lens can achieve the resolution higher than 4K (800 ten thousand pixels), and by taking a 1/2.8' sensor as an example, the zoom lens can achieve the central resolution higher than 300lp/mm and the peripheral 0.7H (70% diagonal position) resolution higher than 1400 TVline.

The present invention takes into account chromatic aberration while taking into account power allocation. Based on the optical chromatic aberration theory, part of the convex lens sheets use ultra-low dispersion glass, the rest convex lens materials are supplemented with ultra-high refractive index materials to ensure the focal power, and medium and high refractive index materials with excellent dispersion characteristics are selected on the negative lens unconventionally to optimize the system chromatic aberration as much as possible. Through repeated material combination and replacement, the infrared confocal of the full-focus section is really realized.

In order to improve the imaging quality of the lens under various multiplying powers, the utility model reduces various optical aberrations and effectively inhibits the chromatic aberration of the system by matching the high-refractive-index glass with the ultra-low dispersion glass material. Different from the traditional single-concave die aspheric surface manufacturing process, in the zooming mobile group, the aspheric surface design of a plurality of double-concave ultralow dispersion glass materials is adopted for the first time, the chromatic aberration of the peripheral field of view is compressed by utilizing the abnormal dispersion characteristic of the materials, and the field curvatures with different magnifications are sequentially corrected by a plurality of concave surfaces, so that the problem that the wide-angle end and the telephoto end cannot be obtained simultaneously is greatly improved. The common zoom lens focuses by a group of positive focal power, and is characterized by simple focusing curve and short focusing stroke; the utility model has the advantages that the structure of negative group focusing is used, the long focusing area is used for making up the image quality loss in short-distance shooting, and a better effect is obtained due to the sufficient space allowance caused by the multi-group linkage zooming. From the wide-angle end to observation with a large field angle or capture of detail in a close range, the color restoration degree and detail reproduction capability of 4K level are achieved.

The utility model further provides an imaging device, wherein the mobile device comprises the zoom lens in the technical scheme, and the imaging device can be a monitoring lens, which is not limited herein.

The above description is only an alternative embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents made by the contents of the present specification and drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (10)

1. A zoom lens is characterized by comprising a lens body, wherein the direction from an object side to an image side along an optical axis of the lens body is from front to back;

the lens main body comprises a lens barrel, a first lens group with positive focal power, a second lens group with negative focal power, a third lens group with positive focal power, a fourth lens group with positive focal power, a fifth lens group with negative focal power, a sixth lens group with positive focal power, a seventh lens group with negative focal power and a photosensitive chip, wherein the first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group and the sixth lens group are sequentially arranged in the lens barrel from front to back;

wherein the zoom lens satisfies the following conditions: 0.04 < fw/f1 < 0.38, and-2.15 < fw/f2 < -0.24, and 0.35 < fw/f3 < 0.04, and 0.1 < fw/f4 < 0.93, and-1.22 < fw/f5 < -0.14, and 0.15 < fw/f61.31, and-0.85 < fw/f7 < -0.09;

wherein fw is a focal length of the zoom lens at a wide-angle end, f1 is a focal length of the first lens group, f2 is a focal length of the second lens group, f3 is a focal length of the third lens group, f4 is a focal length of the fourth lens group, f5 is a focal length of the fifth lens group, f6 is a focal length of the sixth lens group, and f7 is a focal length of the seventh lens group.

2. The zoom lens according to claim 1, wherein the first lens group includes, in order from front to rear, a first lens having positive optical power, a second lens having negative optical power, a third lens having positive optical power, and a fourth lens having positive optical power;

the first lens group and the first, second, third, and fourth lenses satisfy the following conditions: 0.03 < f1/f11 < 0.28, and-2.21 < f1/f12 < -0.25, and 0.11 < f1/f13 < 1.02, and 0.21 < f1/f14 < 1.91;

wherein f1 is the focal length of the first lens group, f11 is the focal length of the first lens, f12 is the focal length of the second lens, f13 is the focal length of the third lens, and f14 is the focal length of the fourth lens.

3. The zoom lens according to claim 1, wherein the second lens group includes, in order from front to rear, a fifth lens having negative optical power, a sixth lens having negative optical power, a seventh lens having positive optical power, and an eighth lens having negative optical power;

the second lens group, the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy the following conditions: 0.21 < f2/f21 < 1.91, and 0.07 < f2/f22 < 0.63, and-0.56 < f2/f23 < -0.06, and 0.05 < f2/f24 < 0.49;

wherein f2 is a focal length of the second lens group, f21 is a focal length of the fifth lens group, f22 is a focal length of the sixth lens group, f23 is a focal length of the seventh lens group, and f24 is a focal length of the eighth lens group.

4. The zoom lens of claim 1, wherein the third lens group includes a ninth lens having positive optical power.

5. The zoom lens according to claim 1, wherein the fourth lens group includes, in order from front to rear, a tenth lens having positive optical power, an eleventh lens having positive optical power, a twelfth lens having negative optical power, and a thirteenth lens having negative optical power;

the fourth lens group and the tenth, eleventh, twelfth, thirteenth lens satisfy the following relationships: 0.25 < f4/f41 < 2.21, and 0.24 < f4/f42 < 2.18, and-0.18 < f4/f43 < -1.65, and 0.01 < f4/f44 < 0.11;

wherein f4 is a focal length of the fourth lens group, f41 is a focal length of the tenth lens, f42 is a focal length of the eleventh lens, f43 is a focal length of the twelfth lens, and f44 is a focal length of the thirteenth lens.

6. The zoom lens according to claim 1, wherein the fifth lens group includes a fourteenth lens having a negative optical power, a fifteenth lens having a negative optical power, and a sixteenth lens having a negative optical power, which are arranged in this order from front to rear;

the fifth lens group and the fourteenth lens, the fifteenth lens, the sixteenth lens satisfy the following relationships: 0.19 < f5/f51 < 1.7, and 0.09 < f5/f52 < 0.82, and 0.06 < f5/f53 < 0.52;

wherein f5 is a focal length of the fifth lens group, f51 is a focal length of the fourteenth lens group, f52 is a focal length of the fifteenth lens group, and f53 is a focal length of the sixteenth lens group.

7. The zoom lens according to claim 1, wherein the sixth lens group includes a seventeenth lens having a negative optical power, an eighteenth lens having a negative optical power, a nineteenth lens having a positive optical power, and a twentieth lens having a positive optical power, which are arranged in this order from front to rear;

the sixth lens group and the seventeenth lens, the eighteenth lens, the nineteenth lens, and the twentieth lens satisfy the following relationships: -1.93 < f6/f61 < -0.21, and-0.16 < f6/f62 < -0.02, and 0.15 < f6/f63 < 1.37, and 0.21 < f6/f64 < 1.85;

wherein f6 is a focal length of the sixth lens group, f61 is a focal length of the seventeenth lens, f62 is a focal length of the eighteenth lens, f63 is a focal length of the nineteenth lens, and f64 is a focal length of the twentieth lens.

8. The zoom lens of claim 1, wherein the seventh lens group comprises a twenty-first lens having a negative optical power.

9. The zoom lens of claim 1, further comprising a stop located between the fourth lens group and the fifth lens group;

the zoom lens satisfies the following conditions: L/TTL is more than 0.09 and less than 0.8;

wherein, L is the distance between the diaphragm and the imaging surface of the zoom lens on the optical axis, and TTL is the total optical length of the zoom lens.

10. An imaging apparatus, characterized in that the imaging apparatus comprises a zoom lens according to any one of claims 1 to 9.

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