CN114265189B - Zoom lens and imaging device - Google Patents

Abstract

The invention discloses a zoom lens and an imaging device, wherein the zoom lens comprises a lens barrel and a lens group, the lens group comprises 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 and a fifth lens group which are sequentially arranged from the object side to the image side, the first lens group and the fifth lens group are fixedly arranged on the lens barrel, and the second lens group, the third lens group and the fourth lens group are movably arranged on the lens barrel along the optical axis direction.

Description

Zoom lens and imaging device

Technical Field

The present invention relates to the field of optical system design, and more particularly, to a zoom lens and an imaging device for an indoor monitoring system or a video system.

Background

Currently, a main stream of high-image-quality zoom monitoring lens in the market needs to have a large enough field angle to obtain a wider field of view, and the lens is often designed to have a wide-angle effect. The design concept of the lens with the wide-angle effect is to sacrifice the distortion of the lens, and to take in as much light as possible with great distortion, so that the image information on the periphery of the picture cannot be distinguished because the huge deformation is seriously compressed in the edge area of the picture, and the imaging quality is poor. In indoor monitoring, in order to ensure that a large-scale shot region can be clearly monitored, a high requirement is placed on distortion of a picture. The existing monitoring lens generally reduces the influence caused by distortion through a plurality of glass aspheric lenses, but the manufacturing cost is higher, and the current zoom lens applied to an indoor monitoring system or a video system starts to develop towards the household and low cost, so the monitoring lens with higher manufacturing cost cannot meet the market demand.

Disclosure of Invention

The invention aims to provide a zoom lens, which aims to solve the technical problem that the wide angle and small distortion of the lens in the prior art cannot coexist.

In order to achieve the above object, the present invention provides a zoom lens having an object side and an image side disposed opposite to each other in an optical axis direction, comprising:

Lens barrel, and

The lens group comprises a first lens group with positive focal power, a second lens group with negative focal power, a diaphragm, a third lens group with positive focal power, a fourth lens group with positive focal power, a fifth lens group and a photosensitive chip which are sequentially arranged from the object side to the image side, wherein the first lens group and the fifth lens group are fixedly arranged on the lens barrel, the second lens group, the third lens group and the fourth lens group are movably arranged on the lens barrel along the optical axis direction, and the second lens group and the third lens group move cooperatively along the optical axis direction so as to enable the zoom lens to zoom, and the fourth lens group moves along the optical axis direction so as to enable the zoom lens to focus;

Wherein the zoom lens satisfies the following conditions that 0.046< fw/f1<0.068, and-0.478 < fw/f2< -0.319, and 0.089< fw/f3<0.134, and 0.113< fw/f4<0.169, and-0.262 < fw/f5<0.262;

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, and f5 is a focal length of the fifth lens group.

Optionally, the first lens group includes a first lens having negative optical power, a second lens having positive optical power, and a third lens having positive optical power, which are sequentially disposed from the object side to the image side;

Wherein the first lens group and the first, second and third lenses meet the conditions of-0.783 < f1/f11< -0.522, and 0.665< f1/f12<0.997, and 0.716< f1/f13<1.074;

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, and f13 is the focal length of the third lens.

Optionally, the second lens group includes a fourth lens with negative focal power, a fifth lens with negative focal power, a sixth lens with negative focal power, a seventh lens with negative focal power, an eighth lens with positive focal power, and the fifth lens is a plastic aspheric lens, which are sequentially arranged from the object side to the image side;

Wherein the second lens group and the fourth, fifth, sixth, seventh, eighth lenses meet the following conditions 0.669< f2/f21<1.004, and-0.089 < f2/f22<0.089, and 0.251< f2/f23<0.586, and 0.236< f2/f24<0.55, and-0.628 < f2/f25< -0.338;

Wherein f2 is a focal length of the second lens group, f21 is a focal length of the fourth lens, f22 is a focal length of the fifth lens, f23 is a focal length of the sixth lens, f24 is a focal length of the seventh lens, and f25 is a focal length of the eighth lens.

Optionally, the third lens group includes a ninth lens having positive optical power, a tenth lens having positive optical power, an eleventh lens having negative optical power, which are sequentially disposed from the object side to the image side, and the ninth lens is a glass aspherical lens;

Wherein the third lens group and the ninth, tenth, eleventh lenses meet the following conditions 1.114< f3/f31<2.069, and 0.569< f3/f32<1.056, and-1.99 < f3/f33< -1.071;

wherein f3 is a focal length of the third lens group, f31 is a focal length of the ninth lens, f32 is a focal length of the tenth lens, and f33 is a focal length of the eleventh lens.

Optionally, the fourth lens group includes a twelfth lens having positive optical power, a thirteenth lens having positive optical power, a fourteenth lens having positive optical power, a fifteenth lens having negative optical power, and a sixteenth lens sequentially disposed from the object side to the image side, and the sixteenth lens is a plastic aspherical lens;

Wherein the fourth lens group and the twelfth, thirteenth, fourteenth, fifteenth, sixteenth lenses meet the following conditions 0.653< f4/f41<1.088, and 0.897< f4/f42<1.666, and 1.122< f4/f43<1.869, and-4.222 < f4/f44< -2.533, and-0.84 < f4/f45<0.252;

Wherein f4 is a focal length of the fourth lens group, f41 is a focal length of the twelfth lens, f42 is a focal length of the thirteenth lens, f43 is a focal length of the fourteenth lens, f44 is a focal length of the fifteenth lens, and f45 is a focal length of the sixteenth lens.

Optionally, the fifth lens group includes a seventeenth lens, and the seventeenth lens is a plastic aspheric lens.

Optionally, the zoom lens satisfies the following condition:

Wherein, And TTL is the total optical length of the zoom lens, wherein the TTL is the effective clear aperture of the first lens.

Optionally, the zoom lens satisfies the following conditions that 0.271< DeltaZ 1 _W-T/TTL <0.366;

Wherein Δz _W-T is the relative displacement between the second lens group when the zoom lens is at the wide-angle end position and the zoom lens is at the telephoto end position, and TTL is the total optical length of the zoom lens.

Optionally, the zoom lens satisfies the following conditions that 0.026< DeltaZ 2 _W-T/TTL <0.062;

Wherein Δz2 _W-T is a relative displacement between the third lens group when the zoom lens is at the wide-angle end position and the zoom lens is at the telephoto end position, and TTL is an optical total length of the zoom lens.

An imaging device comprising the zoom lens according to the above technical solution.

In the technical scheme provided by the invention, the first lens group and the fifth lens group are fixedly arranged on the lens barrel, the second lens group, the third lens group and the fourth lens group are movably arranged on the lens barrel along the optical axis direction, wherein the second lens group and the third lens group are used for zooming, the fourth lens group is used for focusing, the second lens group and the third lens group move cooperatively along the optical axis direction, so that the zoom lens is zoomed from the wide angle end to the telephoto end, the fourth lens group is driven by external force to move along the optical axis corresponding to the positions, the imaging wavelengths and the imaging object distances of the second lens group and the third lens group, the zoom lens keeps the imaging surface clear in the zooming process, the first lens group has positive focal power, the second lens group has negative focal power, the third lens group has positive focal power, the fourth lens group has positive focal power, the fifth focal power and the zoom lens can be reduced in the aperture ratio, and the zoom lens can be set to the wide angle ratio, and the zoom lens can be reduced in the wide angle ratio, and the zoom lens can be set to the wide aperture ratio.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

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

FIG. 2 is a schematic view of the zoom lens in FIG. 1 at an intermediate magnification;

FIG. 3 is a schematic view of the zoom lens of FIG. 1 at the telephoto end;

FIG. 4 is an aberration diagram of the zoom lens of FIG. 2 at the wide-angle end;

FIG. 5 is a field curvature diagram of the zoom lens of FIG. 2 at the wide-angle end;

Fig. 6 is a distortion diagram of the zoom lens in fig. 2 at the wide-angle end;

FIG. 7 is a spherical aberration diagram of the zoom lens of FIG. 1 at an intermediate magnification;

FIG. 8 is a field curvature diagram of the zoom lens of FIG. 1 at an intermediate magnification;

FIG. 9 is a distortion chart of the zoom lens of FIG. 1 at an intermediate magnification;

FIG. 10 is an aberration diagram of the zoom lens of FIG. 3 at the telephoto end;

FIG. 11 is a field curvature diagram of the zoom lens of FIG. 3 at the telephoto end;

FIG. 12 is a distortion chart of the zoom lens of FIG. 3 at the telephoto end;

fig. 13 is a schematic view of a zoom lens according to a second embodiment of the present invention at a wide-angle end;

FIG. 14 is a schematic view of the zoom lens of FIG. 13 at an intermediate magnification;

FIG. 15 is a schematic view of the zoom lens of FIG. 13 at the telephoto end;

FIG. 16 is an aberration diagram of the zoom lens of FIG. 14 at the wide-angle end;

FIG. 17 is a field curvature diagram of the zoom lens of FIG. 14 at the wide-angle end;

fig. 18 is a distortion diagram of the zoom lens in fig. 14 at the wide-angle end;

FIG. 19 is an aberration diagram of the zoom lens of FIG. 13 at intermediate magnification;

FIG. 20 is a field curvature diagram of the zoom lens of FIG. 13 at an intermediate magnification;

FIG. 21 is a distortion chart of the zoom lens of FIG. 13 at an intermediate magnification;

FIG. 22 is an aberration diagram of the zoom lens of FIG. 15 at the telephoto end;

FIG. 23 is a field curvature of the lens assembly of FIG. 15 at the telephoto end;

Fig. 24 is a distortion diagram of the zoom lens in fig. 15 when it is at the telephoto end.

Reference numerals illustrate:

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the case where a directional instruction is involved in the embodiment of the present invention, the directional instruction is merely used to explain the relative positional relationship, movement condition, etc. between the components in a specific posture, and if the specific posture is changed, the directional instruction is changed accordingly.

In addition, if there is a description of "first", "second", etc. in the embodiments 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 a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" as it appears throughout includes three parallel schemes, for example "A and/or B", including the A scheme, or the B scheme, or the scheme where A and B are satisfied simultaneously. Also, the technical solutions of the embodiments may be combined with each other, but it is necessary to base the implementation on the basis of those skilled in the art, and when the technical solutions are contradictory or cannot be implemented, it should be considered that the combination of the technical solutions does not exist and is not within the scope of protection claimed by the present invention.

The present invention provides a zoom lens, which aims to solve the technical problem that the wide angle and small distortion cannot coexist in the prior art, and referring to fig. 1 to 24, the drawings show specific embodiments of the zoom lens.

First embodiment

Fig. 1 to 12 are diagrams illustrating a first embodiment of a zoom lens according to the present invention.

Referring to fig. 1 to 3, the zoom lens has an object side and an image side which are disposed opposite to each other along an optical axis direction, the zoom lens includes a lens barrel (not shown in the figure) and a lens group, the lens barrel is disposed to extend along the optical axis direction, the lens group includes a first lens group 1 having positive optical power, a second lens group 2 having negative optical power, a diaphragm 6, a third lens group 3 having positive optical power, a fourth lens group 4 having positive optical power, a fifth lens group 5, and a photosensitive chip 8, which are disposed in order from the object side to the image side, the first lens group 1, the fifth lens group 5, and the photosensitive chip 8 are fixedly mounted to the lens barrel, the second lens group 2, the third lens group 3, and the fourth lens group 4 are movably mounted to the lens group along the optical axis direction, and the second lens group 2 and the third lens group 3 are moved in a direction of the focal length direction in cooperation with the lens group 3, and the lens group 4 are driven to move along the optical axis direction, and the lens group 4 is driven to a clear angle direction, and the lens group is driven by the lens group 2 and the lens group is driven to move along the optical axis direction.

And the zoom lens satisfies the following conditions that 0.046< fw/f1<0.068, and-0.478 < fw/f2< -0.319, and 0.089< fw/f3<0.134, and 0.113< fw/f4<0.169, and-0.262 < fw/f5<0.262, 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 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, and f5 is a focal length of the fifth lens group 5.

In the 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 as follows, fw/f1=0.055, fw/f2= -0.374, fw/f3=0.106, fw/f4=0.127, and fw/f5=0.215.

The second lens group 2, the third lens group 3, and the fourth lens group 4 may be driven by an external force to move along the optical axis direction, wherein the external force may be driven by a driving motor or manually adjusted without limitation.

In the technical scheme provided by the invention, the first lens group 1 and the fifth lens group 5 are fixedly arranged on the lens barrel, the second lens group 2, the third lens group 3 and the fourth lens group 4 are movably arranged on the lens barrel along the optical axis direction, wherein the second lens group 2 and the third lens group 3 are used for zooming, the fourth lens group 4 is used for focusing, the second lens group 2 and the third lens group 3 are cooperatively moved along the optical axis direction, so that the zoom lens is zoomed to the telescopic end from the wide-angle end, the fourth lens group 4 is driven by an external force to move along the optical axis corresponding to the positions, the imaging wavelengths and the imaging object distances of the second lens group 2 and the third lens group 3, the zoom lens keeps the imaging surface of the imaging surface clear in the zooming process, the first lens group 1 has positive focal power, the second lens group 2 has negative focal power, the third lens group has the positive focal power, the fourth lens group has the positive focal power, the positive focal power and the fifth lens group 4 has the positive focal power, and the positive focal power and the fifth focal power 4 has the positive focal power and the positive focal power 4 is reasonably limited by the size.

Specifically, the first lens group 1 comprises a first lens 11 with negative optical power, a second lens 12 with positive optical power, and a third lens 13 with positive optical power, which are sequentially arranged from the object side to the image side, wherein the first lens group 1, the first lens 11, the second lens 12, and the third lens 13 meet the following conditions that-0.783 < f1/f11< -0.522, 0.665<1/f12<0.997, and 0.716< f1/f13<1.074, 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, and f13 is the focal length of the third lens 13.

More specifically, in the present embodiment, the first lens 11 is a convex-concave spherical lens having negative optical power, i.e., the object side surface of the first lens 11 is a convex surface, the image side surface is a concave surface, the second lens 12 is a convex-concave spherical lens having positive optical power, and the third lens 13 is a convex-concave spherical lens having positive optical power, and the focal length ratio of the first lens group to each of the lenses is specifically shown as f1/f11= -0.589, f1/f12 = 0.763, f1/f13 = 0.857;

Further, the first lens 11 and the second lens 12 form a first cemented lens having positive optical power by cemented, and satisfy the condition that 0.124< f1/f1112<0.23, where f1 is the focal length of the first lens group 1 and f1112 is the focal length of the first cemented lens.

In this embodiment, the ratio of the first lens group to the first cemented lens is specifically f1/f1112=0.164.

Still further, each lens in the first lens group 1 satisfies the following conditions 1.7< ND11<2.1, 1.4< ND12<1.7, 1.6< ND13<2, and 10< VD11<40, and 60< VD12<100, and 30< VD13<65, respectively, wherein ND11 is the refractive index of the first lens 11, ND12 is the refractive index of the second lens 12, ND13 is the refractive index of the third lens 13, VD11 is the Abbe number of the first lens 11, VD12 is the Abbe number of the second lens 12, and VD13 is the Abbe number of the third lens 13, respectively, wherein in this embodiment, the specific refractive indices and Abbe numbers of the lenses are shown in Table 1 below.

Specifically, the second lens group 2 comprises a fourth lens 21 with negative focal power, a fifth lens 22, a sixth lens 23 with negative focal power, a seventh lens 24 with negative focal power, and an eighth lens 25 with positive focal power, which are sequentially arranged from the object side to the image side, wherein the fifth lens is a plastic aspheric lens, the focal power of the fifth lens can be positive or negative, the second lens group 2, the fourth lens 21, the fifth lens 22, the sixth lens 23, the seventh lens 24 and the eighth lens 25 satisfy the following conditions that 0.669< f2/f21<1.004, 0.089< f2/f22<0.089, 0.251< f2/f23<0.586, 0.236< f2/f24 0.55, 0.628< f2/f25, wherein the fourth lens group 2, the sixth lens 23, the seventh lens 24, the seventh lens 25, the seventh lens 23, the eighth lens 25 and the seventh lens 23.

More specifically, in the present embodiment, the fifth lens 22 is a positive power, the fourth lens 21 is a convex-concave spherical lens having negative power, the fifth lens 22 is a convex-concave aspheric lens, the sixth lens 23 is a biconcave spherical lens having negative power, the seventh lens 24 is a concave-convex spherical lens having negative power, the eighth lens 25 is a convex lens having positive power, i.e., the object side of the eighth lens is a plane, the image side is a convex surface, the focal length ratio of the second lens group to each lens is as shown below f2/f21=0.823, f2/f22=2.2e-4, f2/f23=0.414, f2/f24=0.29, f2/f25= -0.433, and E-4 represents the power of 10 to-4.

Specifically, the third lens group 3 includes a ninth lens 31 having positive power, a tenth lens 32 having positive power, an eleventh lens 33 having negative power, which are disposed in this order from the object side to the image side, and the ninth lens is a glass aspherical lens, and the third lens group 3, the ninth lens 31, the tenth lens 32, and the eleventh lens 33 satisfy the following conditions that 1.114< f3/f31<2.069, and 0.569< f3/f32<1.056, and-1.99 < f3/f33< -1.071, wherein f3 is a focal length of the third lens group 3, f31 is a focal length of the ninth lens 31, f32 is a focal length of the tenth lens 32, and f33 is a focal length of the eleventh lens 33.

More specifically, in the present embodiment, the ninth lens 31 is a biconvex aspherical lens having positive power, the tenth lens 32 is a biconvex spherical lens having positive power, the eleventh lens 33 is a convex-concave spherical lens having negative power, and the focal length ratio of the third lens group 3 to each of the lenses is as follows, f3/f31=1.435, f3/f32=0.787, and f3/f33= -1.428.

Specifically, the fourth lens group 4 comprises a twelfth lens 41 with positive focal power, a thirteenth lens 42 with positive focal power, a fourteenth lens 43 with positive focal power, a fifteenth lens 44 with negative focal power and a sixteenth lens 45 which are sequentially arranged from the object side to the image side, wherein the focal power of the sixteenth lens can be positive or negative, the fourth lens group 4 and the twelfth lens 41, the thirteenth lens 42, the fourteenth lens 43, the fifteenth lens 44 and the sixteenth lens 45 satisfy the following conditions that 0.653< f4/f41<1.088, 0.897< f4/f42<1.666, 1.122< f4/f43<1.869, 4.222< f4/f44< -2.533, 0.84 f4/f45, 4 f42, and 45 f42, and 42 f42 are the thirteenth lens, and 45 f 42.

More specifically, in the present embodiment, the twelfth lens 41 is a convex-concave spherical lens having positive power, the thirteenth lens 42 is a biconvex spherical lens having positive power, the fourteenth lens 43 is a biconvex spherical lens having positive power, the fifteenth lens 44 is a biconcave spherical lens having negative power, the sixteenth lens 45 is a convex-concave spherical lens having negative power, and the focal length ratio of the fourth lens group 4 to each of them is shown as f4/f41=0.858, f4/f42=1.249, f4/f43=1.531, f4/f44= -3.409, f4/f45= -0.68.

Further, the fourteenth lens 43 and the fifteenth lens 44 form a second cemented lens by cemented, the second cemented lens having negative optical power and satisfying the condition-2 < f4/f4344< -1.1, wherein f4 is a focal length of the fourth lens group 4, and f4344 is a focal length of the second cemented lens.

In the present embodiment, the specific ratio of the fourth lens group to the second cemented lens is f4/f4344= -1.549.

Specifically, in the present embodiment, the fifth lens group 5 includes a seventeenth lens 51, the seventeenth lens 51 is a plastic aspherical lens, and the optical power of the seventeenth lens may be positive or negative.

More specifically, in the present embodiment, the seventeenth lens is a biconvex lens of positive optical power.

It will be appreciated that the surface of the photosensitive chip 8 facing the object side is an imaging surface.

Specifically, the zoom lens further includes a diaphragm 6, where the diaphragm 6 is located between the second lens group 2 and the third lens group 3, that is, the diaphragm 6 is located between the eighth lens 25 and the ninth lens 31, in this embodiment, the diaphragm 6 is an adjustable diaphragm, the adjustable diaphragm can perform a corresponding aperture zoom measure along with a change of ambient illumination intensity, and the zoom lens satisfies the following condition that 0.318< L/TTL <0.43, where L is a distance between the diaphragm 6 and the imaging plane on the optical axis, and TTL is an optical total length of the zoom lens, where it is to be noted that the optical total length is a distance between an object side center vertex of the first lens 11 and the imaging plane.

In this embodiment, the ratio of the distance from the diaphragm 6 to the imaging plane to the total optical length of the zoom lens is L/ttl=0.381.

Specifically, in this embodiment, the zoom lens further includes a filter, the filter is located between the fifth lens group 5 and the imaging surface, and the filter 7 is used to filter out light rays and stray light in an unnecessary wavelength band, so as to improve imaging quality.

Specifically, the imaging surface may be understood as a surface of the photosensitive chip facing the object side, that is, a surface of an imaging element such as a CCD or a CMOS, more specifically, in this embodiment, the imaging surface is a surface of a CMOS solid-state imaging element (in this embodiment, a CMOS size is 1/2.8"inch h×v=5.566mm×3.13 mm), and it is understood that light carrying subject information can sequentially pass through the first lens group 1, the second lens group 2, the diaphragm 6, the third lens group 3, the fourth lens group 4, the fifth lens group 5, the filter, and finally be imaged on the imaging surface.

Specifically, the zoom lens satisfies the following conditions: Wherein, The TTL is the total optical length of the zoom lens, which is the effective clear aperture of the first lens 11.

In the present embodiment, the ratio of the effective clear aperture of the first lens 11 to the total optical length of the zoom lens:

Specifically, the zoom lens meets the following conditions that 0.271< DeltaZ 1 _W-T/TTL <0.366, wherein DeltaZ _W-T is the relative displacement of the second lens group when the zoom lens is at a wide-angle end position and the zoom lens is at a telescopic end position, and TTL is the total optical length of the zoom lens.

In the embodiment, the ratio of the moving amount of the second lens group when the zoom lens is from the wide-angle end to the telephoto end to the total optical length of the zoom lens is ΔZ1 _W-T/TTL=0.311;

Specifically, the zoom lens meets the following conditions that 0.026< DeltaZ 2 _W-T/TTL <0.062, wherein DeltaZ 2 _W-T is the relative displacement of the third lens group when the zoom lens is at a wide-angle end position and the zoom lens is at a telescopic end position, and TTL is the total optical length of the zoom lens.

In the embodiment, the ratio of the moving amount of the third lens group when the zoom lens is from the wide-angle end to the telephoto end to the total optical length of the zoom lens is ΔZ2 _W-T/TTL=0.048.

Specifically, in the present embodiment, parameters of the zoom lens are as follows:

The wide-angle end focal length fw=3.38 mm, the telescopic end focal length ft=40.9 mm, the wide-angle end f-number Fno _w =1.8, the telescopic end f-number Fno _T =3.4, the wide-angle end horizontal field angle FOVH _w =81°, the telescopic end half-field angle FOVH _T =7.5°, the optical distortion range is between-5% and 5%, and the total optical length TTL=102 mm of the zoom lens.

Specifically, in this embodiment, the refractive index, the radius of curvature and the thickness interval of the lens material are shown in the following table:

Table 1 parameters of the lenses

In particular, in the present embodiment, the fifth lens, the sixteenth lens and the seventeenth lens are aspheric plastic lenses, the ninth lens is an aspheric glass lens, and the aspheric lens is characterized in that the curvature continuously changes from the center of the lens to the periphery of the lens, and the aspheric lens has a better radius of curvature characteristic, and has the advantages of improving distortion aberration and improving astigmatic aberration, and after the aspheric lens is adopted, aberration occurring during imaging can be eliminated as much as possible, thereby improving imaging quality of the lens, and when the lens is made of glass, influence of temperature on optical performance of the lens can be reduced, quality of the optical lens can be reduced by the lens made of plastic material, and cost can be reduced.

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

Wherein c is the curvature corresponding to the radius, y is the radial coordinate (the unit is the same as the unit of the lens length), k is the conic coefficient, (the surface shape curve is hyperbola when the k coefficient is smaller than-1, parabola when the k coefficient is equal to-1, ellipse when the k coefficient is between-1 and 0, circle when the k coefficient is equal to 0, oblate when the k coefficient is larger than 0), A, B, C, D, E, F is the higher aspheric coefficient (refer to the following table 2), and the shape and the size of the aspheric surfaces of the object side and the image side of the lens can be set through the parameters.

Table 2 conical and aspherical coefficients for aspherical lenses

R

K

A

B

C

D

E

F

S8

61.23

-96.94

9.85E-05

-3.01E-05

3.84E-07

7.59E-08

-3.97E-09

3.37E-11

S9

60.39

-11.81

7.97E-04

1.26E-05

-4.80E-06

4.81E-07

-1.87E-08

1.77E-10

S16

14.52

-95.83

3.01E-04

-6.56E-06

1.66E-07

-2.19E-09

1.66E-11

-1.28E-13

S17

-279.46

-98.67

2.15E-04

-7.26E-06

1.66E-07

-8.64E-10

-2.94E-11

2.59E-13

S29

23.50

-8.84

2.44E-04

-6.19E-06

5.08E-08

-1.96E-09

6.87E-11

-1.94E-12

S30

10.93

-35.56

-5.94E-05

-1.36E-06

7.75E-09

-3.01E-09

1.04E-10

-2.15E-12

S31

11.54

-27.38

3.50E-03

-3.34E-04

3.90E-05

-3.70E-06

1.87E-07

-4.97E-09

S32

-30.17

-52.52

4.21E-03

-4.57E-04

5.36E-05

-4.68E-06

1.54E-07

-1.64E-09

Table 3 zoom data of zoom lens at wide-angle end, intermediate magnification position, and telephoto end, respectively

In this embodiment, please refer to fig. 1 to 3, which are schematic structural diagrams of the zoom lens at the wide-angle end, at the intermediate magnification, and at the telephoto end, respectively, wherein the intermediate magnification can be understood as a schematic positional diagram of each lens group in the zoom lens when the zoom lens is between the wide-angle end and the telephoto end.

Fig. 4 to 6 show an aberration diagram (longitudinal aberration), a field curvature diagram (fied curvature), and a distortion diagram (aberration) when the zoom lens is at the wide-angle end, wherein d-line (λ=588 nm), S, T in the diagrams are aberrations corresponding to the sagittal image plane and the meridional image plane, respectively.

Referring to fig. 7 to 9, an aberration diagram, a field curvature diagram, and a distortion diagram of the zoom lens at an intermediate magnification are shown, wherein d-line (λ=588 nm), S, T in the diagram are aberrations corresponding to a sagittal image plane and a meridional image plane, respectively.

Referring to fig. 10 to 12, a spherical aberration diagram, a field curvature diagram, and a distortion diagram when the zoom lens is at a telephoto end are shown, wherein d-line (λ=588 nm), S, T in the diagram are aberrations corresponding to a sagittal image plane and a meridional image plane, respectively.

As is clear from the above-described figures, the zoom lens according to the present embodiment can obtain good correction of spherical aberration, curvature of field, and distortion at the intermediate magnification, the wide-angle end, and the telephoto end, respectively.

Second embodiment

Fig. 13 to 24 are second embodiments of the zoom lens.

It should be noted that, the following embodiments follow some of the foregoing embodiments, and descriptions of the same technical content are omitted, and reference may be made to some of the foregoing embodiments with respect to the same element names, so that the following embodiments will not be repeated.

The difference between the present embodiment and the first embodiment is that the seventeenth lens 51 is a concave-convex aspheric plastic lens having positive optical power.

Specifically, in the present embodiment, parameters of the zoom lens are as follows:

The wide-angle end focal length fw=3.42 mm, the telescopic end focal length ft=41.3 mm, the wide-angle end f-number Fno _w =1.8, the telescopic end f-number Fno _T =3.4, the wide-angle end horizontal field angle FOVH _w =80°, the telescopic end half-field angle FOVH _T =7.4°, the optical distortion range is between-5% and 5%, and the total optical length TTL=101.6 mm of the zoom lens.

Specifically, in this embodiment, the refractive index, the radius of curvature and the thickness interval of the lens material are shown in the following table:

Table 4 parameters of the lenses

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

Wherein c is the curvature corresponding to the radius, y is the radial coordinate (the unit is the same as the unit of the lens length), k is the conic coefficient, (the surface shape curve is hyperbola when the k coefficient is smaller than-1, parabola when the k coefficient is equal to-1, ellipse when the k coefficient is between-1 and 0, circle when the k coefficient is equal to 0, oblate when the k coefficient is larger than 0), A, B, C, D, E, F is the higher aspheric coefficient (refer to the following table 5), and the shape and the size of the aspheric surfaces of the object side and the image side of the lens can be set through the parameters.

TABLE 5 Cone coefficient and aspherical coefficient for aspherical lenses in this example

R

K

A

B

C

D

E

F

S8

136.74

-59.34

3.31E-04

-7.37E-06

2.20E-07

-2.90E-09

2.41E-11

-1.15E-13

S9

76.90

-63.10

2.67E-04

-7.47E-06

2.24E-07

-2.42E-09

1.25E-11

-9.86E-14

S16

14.19

-8.36

2.52E-04

-6.32E-06

4.69E-08

-3.25E-10

-7.63E-12

-8.33E-13

S17

-228.37

96.32

-6.09E-05

-3.60E-07

-1.18E-07

5.25E-09

-1.51E-10

8.46E-13

S29

18.92

-2.31

-1.50E-04

1.77E-05

-4.37E-06

5.24E-07

-2.82E-08

5.81E-10

S30

14.69

-17.03

9.47E-04

3.13E-05

-1.06E-05

1.39E-06

-8.20E-08

1.93E-09

S31

-470.11

-399.42

-1.43E-04

-6.49E-05

1.33E-05

-2.64E-06

1.61E-07

-3.82E-09

S32

-10.47

-7.81

1.83E-03

-2.11E-04

2.18E-05

-3.33E-06

1.96E-07

-4.13E-09

Table 6 zoom data of zoom lens at wide-angle end, intermediate magnification position, and telephoto end, respectively

	Wide angle of view	Intermediate multiplying power	Telescope
				T(5)	0.70	27.97	33.88
T(15)	33.75	6.48	0.57
				T(ST)	4.55	0.72	0.52
T(21)	11.08	7.10	2.82
				T(30)	1.54	9.34	13.83

As can be seen from the above parameter data, the ratio data of the zoom lens in this embodiment are as follows:

The ratio of the focal length of the zoom lens at the wide-angle end to the focal length of each lens group is as follows, fw/f1=0.054, fw/f2= -0.391, fw/f3=0.109, fw/f4=0.145, fw/f5=0.172;

The focal length ratio of the first lens group 1 to each lens is shown as f1/f11= -0.653, f1/f12=0.817, f1/f13=0.843, f1/f1112=0.154;

The focal length ratio of the second lens group 2 to each lens is shown as f2/f21=0.784, f2/f22=0.032, f2/f23=0.304, f2/f24=0.385, f2/f25= -0.447;

The focal length ratio of the third lens group 3 to each lens is shown as f3/f31=1.462, f3/f32=0.696, f3/f33= -1.359;

The focal length ratio of the fourth lens group 4 to each of the lenses is shown as f4/f41=0.773, f4/f42=1.085, f4/f43=1.28, f4/f44= -2.931, f4/f45= -0.167, f4/f4344= -1.591;

The ratio of the distance from the diaphragm 6 to the imaging surface to the total optical length of the zoom lens is L/ttl=0.367;

Ratio of the effective clear aperture of the first lens 11 to the total optical length of the zoom lens:

A ratio of a moving amount of the second lens group when the zoom lens is from a wide angle end to a telescopic end to an optical total length of the zoom lens, wherein DeltaZ1 _W-T/TTL=0.325;

The ratio of the moving amount of the third lens group when the zoom lens is from the wide angle end to the telescopic end to the total optical length of the zoom lens is delta Z2 _W-T/TTL=0.04.

In this embodiment, please refer to fig. 13 to 15, which are schematic structural diagrams of the zoom lens at the wide-angle end, the intermediate magnification and the telephoto end respectively;

Referring to fig. 16 to 18, a spherical aberration diagram, a field curvature diagram, and a distortion diagram when the zoom lens is at the wide angle end are shown, wherein d-line (λ=588 nm), S, T in the diagram are aberrations corresponding to the sagittal image plane and the meridional image plane, respectively.

Referring to fig. 19 to 21, a spherical aberration diagram, a field curvature diagram, and a distortion diagram of the zoom lens at an intermediate magnification are shown, wherein d-line (λ=588 nm), S, T in the diagram are aberrations corresponding to a sagittal image plane and a meridional image plane, respectively.

Referring to fig. 22 to 24, a spherical aberration diagram, a field curvature diagram, and a distortion diagram when the zoom lens is at a telephoto end are shown, wherein d-line (λ=588 nm), S, T in the diagrams are aberrations corresponding to a sagittal image plane and a meridional image plane, respectively.

As is clear from the above-described figures, the zoom lens according to the present embodiment can obtain good correction of spherical aberration, curvature of field, and distortion at the intermediate magnification, the wide-angle end, and the telephoto end, respectively.

In summary, the zoom lens of the present invention adopts a five-group structure of positive and negative positive and positive aspheric surfaces, wherein two zoom groups are one focusing group and two fixed groups, and as the second lens group and the third lens group move correspondingly, the focal length changes, the fourth lens group is used for focusing, the focal length (taking 1/2.8 as a CCD of 16:9 as an example) can change at a WIDE angle end <3.5mm, a telephoto end >40mm, the shooting angle level at the WIDE angle end (WIDE) is >80 degrees, the optical distortion of the WIDE angle end and the telephoto end is within 5%, and the zoom lens has WIDE angle, small distortion and large zoom effects, and the zoom lens contains 3 plastic aspheric surfaces and only 1 glass aspheric surface, so that the manufacturing cost is sufficiently reduced under the condition of ensuring good optical performance.

Although the zoom lens uses a plastic aspheric lens, the temperature change has little influence on the performance of the lens by limiting the focal length of the zoom lens, the back focus change is little, the performance is stable under the condition of indoor environment change, and refocusing is not needed.

The zoom lens uses an adjustable aperture, has extremely high photosensitivity under the condition that the aperture number at the wide-angle end reaches 1.8 and the aperture number at the telescopic end reaches 3, and can shoot clearer pictures even in a darker environment.

The distance between the first lens group and the photosensitive chip is fixed, and the distance between the first lens group and the photosensitive chip is smaller than 102mm (taking 1/2.8' CCD as an example, and using CCD with other sizes for proper scaling).

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

In addition, the invention also provides an imaging device, which comprises the zoom lens.

The foregoing description is only of alternative embodiments of the present invention, and is not intended to limit the scope of the invention, and all equivalent structural changes made by the description of the present invention and the accompanying drawings or direct/indirect application in other related technical fields are included in the scope of the invention.

Claims (10)

1. A zoom lens having an object side and an image side disposed opposite to each other in an optical axis direction, comprising:

Lens barrel, and

The lens group comprises a first lens group with positive focal power, a second lens group with negative focal power, a diaphragm, a third lens group with positive focal power, a fourth lens group with positive focal power, a fifth lens group and a photosensitive chip which are sequentially arranged from the object side to the image side, wherein the first lens group and the fifth lens group are fixedly arranged on the lens barrel, the second lens group, the third lens group and the fourth lens group are movably arranged on the lens barrel along the optical axis direction, and the second lens group and the third lens group move cooperatively along the optical axis direction so as to enable the zoom lens to zoom, and the fourth lens group moves along the optical axis direction so as to enable the zoom lens to focus;

Wherein the zoom lens satisfies the following conditions that 0.046< fw/f1<0.068, and-0.478 < fw/f2< -0.319, and 0.089< fw/f3<0.134, and 0.113< fw/f4<0.169, and-0.262 < fw/f5<0.262;

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, and f5 is a focal length of the fifth lens group.

2. The zoom lens according to claim 1, wherein the first lens group includes a first lens having negative optical power, a second lens having positive optical power, and a third lens having positive optical power, which are disposed in order from the object side to the image side;

Wherein the first lens group and the first, second and third lenses meet the conditions of-0.783 < f1/f11< -0.522, and 0.665< f1/f12<0.997, and 0.716< f1/f13<1.074;

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, and f13 is the focal length of the third lens.

3. The zoom lens according to claim 1, wherein the second lens group includes a fourth lens having negative optical power, a fifth lens having negative optical power, a sixth lens having negative optical power, a seventh lens having negative optical power, an eighth lens having positive optical power, which are disposed in this order from the object side to the image side, and wherein the fifth lens is a plastic aspherical lens;

Wherein the second lens group and the fourth, fifth, sixth, seventh, eighth lenses meet the following conditions 0.669< f2/f21<1.004, and-0.089 < f2/f22<0.089, and 0.251< f2/f23<0.586, and 0.236< f2/f24<0.55, and-0.628 < f2/f25< -0.338;

Wherein f2 is a focal length of the second lens group, f21 is a focal length of the fourth lens, f22 is a focal length of the fifth lens, f23 is a focal length of the sixth lens, f24 is a focal length of the seventh lens, and f25 is a focal length of the eighth lens.

4. The zoom lens according to claim 1, wherein the third lens group includes a ninth lens having positive optical power, a tenth lens having positive optical power, an eleventh lens having negative optical power, which are disposed in order from the object side to the image side, and the ninth lens is a glass aspherical lens;

Wherein the third lens group and the ninth, tenth, eleventh lenses meet the following conditions 1.114< f3/f31<2.069, and 0.569< f3/f32<1.056, and-1.99 < f3/f33< -1.071;

wherein f3 is a focal length of the third lens group, f31 is a focal length of the ninth lens, f32 is a focal length of the tenth lens, and f33 is a focal length of the eleventh lens.

5. The zoom lens according to claim 1, wherein the fourth lens group includes a twelfth lens having positive optical power, a thirteenth lens having positive optical power, a fourteenth lens having positive optical power, a fifteenth lens having negative optical power, and a sixteenth lens disposed in this order from the object side to the image side, and the sixteenth lens is a plastic aspherical lens;

Wherein the fourth lens group and the twelfth, thirteenth, fourteenth, fifteenth, sixteenth lenses meet the following conditions 0.653< f4/f41<1.088, and 0.897< f4/f42<1.666, and 1.122< f4/f43<1.869, and-4.222 < f4/f44< -2.533, and-0.84 < f4/f45<0.252;

Wherein f4 is a focal length of the fourth lens group, f41 is a focal length of the twelfth lens, f42 is a focal length of the thirteenth lens, f43 is a focal length of the fourteenth lens, f44 is a focal length of the fifteenth lens, and f45 is a focal length of the sixteenth lens.

6. The zoom lens of claim 1, wherein the fifth lens group comprises a seventeenth lens, the seventeenth lens being a plastic aspherical lens.

7. The zoom lens according to claim 1, wherein the zoom lens satisfies the following condition:

Wherein, And TTL is the total optical length of the zoom lens, wherein the TTL is the effective clear aperture of the first lens.

8. The zoom lens according to claim 1, wherein the zoom lens satisfies the condition that 0.271< Δz1 _W-T/TTL <0.366;

Wherein Δz _W-T is the relative displacement between the second lens group when the zoom lens is at the wide-angle end position and the zoom lens is at the telephoto end position, and TTL is the total optical length of the zoom lens.

9. The zoom lens according to claim 1, wherein the zoom lens satisfies the condition that 0.026< Δz2 _W-T/TTL <0.062;

Wherein Δz2 _W-T is a relative displacement between the third lens group when the zoom lens is at the wide-angle end position and the zoom lens is at the telephoto end position, and TTL is an optical total 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.