CN209765154U

CN209765154U - Zoom lens

Info

Publication number: CN209765154U
Application number: CN201920808724.7U
Authority: CN
Inventors: 张军光; 王世昌
Original assignee: Xiamen Li Ding Au Optronics Co
Current assignee: Xiamen Li Ding Au Optronics Co; Xiamen Leading Optics Co Ltd
Priority date: 2019-05-31
Filing date: 2019-05-31
Publication date: 2019-12-10
Anticipated expiration: 2029-05-31

Abstract

The utility model relates to a camera lens technical field. The utility model discloses a zoom lens, which is provided with twelve lenses, wherein a focusing lens group is formed by a first lens to a fourth lens, and a zooming lens group is formed by a fifth lens to a twelfth lens; the diaphragm is arranged between the focusing lens group and the zoom lens group, the refractive indexes and the surface types of the first lens, the fourth lens, the sixth lens and the seventh lens are correspondingly limited, the third lens and the fourth lens form a cemented lens, the sixth lens and the seventh lens form a cemented lens, the eleventh lens and the twelfth lens form a cemented lens, and the object side surface and the image side surface of the fifth lens are both aspheric surfaces. The utility model has the advantages of the super large leads to light, and is good to the management and control of transfer function, and the resolution is high, and the distortion is little, and visible light is poor, and the imaging quality is high.

Description

Zoom lens

Technical Field

the utility model belongs to the technical field of the camera lens, specifically relate to a zoom lens.

background

with the continuous progress of the technology, in recent years, the optical imaging lens is also rapidly developed and widely applied to various fields such as smart phones, tablet computers, video conferences, security monitoring and the like.

the zoom lens is a camera lens which can change focal length in a certain range, thereby obtaining different field angles, images with different sizes and different scene ranges. The zoom lens can change the shooting range by varying the focal length without changing the shooting distance, and thus is very convenient to use.

however, some zoom lenses in the market currently have the following defects: the low-light characteristic is poor, and a clear color image cannot be realized under the condition of poor light; the distortion control is not good, the object image deformation is large, and the reducibility is poor; the control on the transfer function is poor, the resolution is low, the image sharpness is poor, and the image is not uniform; the focal length span is small, the field angle span is small, and the switching flexibility is poor; when visible light is generated, the color difference is large, and the color restoration is inaccurate.

disclosure of Invention

an object of the utility model is to provide a zoom is used for solving the technical problem that the above-mentioned exists.

In order to achieve the above object, the utility model adopts the following technical scheme: a zoom lens comprises a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens, a seventh lens, a twelfth lens and a fifth lens, wherein the first lens, the second lens, the third lens, the fourth lens, the diaphragm and the fifth lens are sequentially arranged from an object side to; the first lens element to the twelfth lens element each include an object-side surface facing the object side and allowing the imaging light to pass therethrough and an image-side surface facing the image side and allowing the imaging light to pass therethrough;

The first lens element with negative refractive index has a convex object-side surface and a concave image-side surface; the second lens element with negative refractive index has a concave object-side surface and a concave image-side surface; the third lens element with negative refractive index has a concave object-side surface and a concave image-side surface; the fourth lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the image side surface of the third lens and the object side surface of the fourth lens are mutually glued; the first lens to the fourth lens form a focusing lens group;

The fifth lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the sixth lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the seventh lens element with negative refractive index has a concave object-side surface and a convex image-side surface; the eighth lens element with positive refractive index has a concave object-side surface and a convex image-side surface; the ninth lens element with positive refractive power has a convex object-side surface and a convex image-side surface; the tenth lens element with a negative refractive index has a convex object-side surface and a concave image-side surface; the eleventh lens element with positive refractive power has a convex object-side surface and a convex image-side surface; the twelfth lens element with a negative refractive index has a concave object-side surface and a convex image-side surface; the image side surface of the sixth lens and the object side surface of the seventh lens are mutually glued; the image side surface of the eleventh lens and the object side surface of the twelfth lens are mutually glued; the fifth lens to the twelfth lens form a variable power lens group;

the object-side surface and the image-side surface of the fifth lens element are aspheric surfaces, and the zoom lens has only the twelve lenses with refractive index.

Further, the zoom lens further satisfies: 1.55< nd5<1.65, where nd5 denotes the refractive index of the fifth lens at the d-line, respectively.

Further, the zoom lens further satisfies: vd3-vd4>30, where vd3 and vd4 denote the abbe numbers of the third and fourth lenses, respectively, in the d-line.

further, the zoom lens further satisfies: 1.40< nd6<1.50, 85< vd6<95, 1.75< nd7<1.85, 20< vd7<30, vd6-vd7>60, wherein nd6 and nd7 respectively represent refractive indexes of the sixth lens and the seventh lens in a d line, and vd6 and vd7 respectively represent abbe numbers of the sixth lens and the seventh lens in the d line.

Further, the zoom lens further satisfies: vd11-vd12>40, where vd11 and vd12 represent the abbe numbers of the eleventh and twelfth lenses, respectively, in the d-line.

furthermore, the zoom lens further satisfies: 1.50< nd11<1.60, 60< vd11<70, 1.9< nd12<2.0, 20< vd12<30, where nd11 and nd12 respectively represent the refractive indices of the eleventh lens and the twelfth lens in the d-line.

Further, the zoom lens further satisfies: 0.4< fw/BFLw <0.6, wherein fw is the shortest focal length and BFLw is the back focal length at the shortest focal length.

Further, the zoom lens further satisfies: 0.6< ft/BFLt <0.7, where ft is the longest focal length and BFLt is the back focal length at the longest focal length.

Further, the first lens to the twelfth lens are made of glass materials.

The utility model adopts twelve lenses, and through the corresponding design of each lens, the low-light characteristic is good, and under the condition of poor light, clear color images can be realized; distortion is well controlled, the object image deformation is small, and the reducibility is strong; the transfer function is well controlled, the resolution is high, the image sharpness is high, and the images are uniform; the focal length span is large, the field angle span is large, and the switching flexibility is strong; and when visible light is emitted, the color difference management and control are better, and the color reducibility is good.

in addition, the utility model has good infrared confocal performance, small defocusing amount (less than 6 μm) when switching visible infrared, and no need of switching piece or optical filter compensation; under the premise of infrared confocal, the blue-violet edge is well controlled.

Drawings

fig. 1 is a schematic structural view of a first embodiment of the present invention at a shortest focal length;

Fig. 2 is a schematic structural view of the first embodiment of the present invention at the longest focal length;

Fig. 3 is a graph of MTF of 0.435-0.656 μm at the shortest focal length according to the first embodiment of the present invention;

Fig. 4 is a defocus graph of 0.435-0.656 μm visible light at the shortest focal length according to the first embodiment of the present invention;

Fig. 5 is an MTF graph of infrared 850nm at the shortest focal length according to the first embodiment of the present invention;

fig. 6 is a defocus graph of 850nm infrared light at the shortest focal length according to the first embodiment of the present invention;

Fig. 7 is a schematic view of curvature of field and distortion at the shortest focal length according to the first embodiment of the present invention;

fig. 8 is a schematic diagram of a chromatic aberration curve diagram when the first embodiment of the present invention is at the shortest focal length;

Fig. 9 is a schematic view of longitudinal aberration at the shortest focal length according to the first embodiment of the present invention;

fig. 10 is a graph of MTF of 0.435-0.656 μm at the longest focal length according to the first embodiment of the present invention;

Fig. 11 is a defocus graph of 0.435-0.656 μm visible light at the longest focal length according to the first embodiment of the present invention;

fig. 12 is an MTF graph of infrared 850nm at the longest focal length according to the first embodiment of the present invention;

fig. 13 is a defocus graph of 850nm infrared light at the longest focal length according to the first embodiment of the present invention;

fig. 14 is a schematic view of curvature of field and distortion at the longest focal length according to the first embodiment of the present invention;

Fig. 15 is a schematic diagram of a chromatic aberration curve when the focal length is longest according to the first embodiment of the present invention;

Fig. 16 is a diagram illustrating longitudinal aberrations at the longest focal length according to the first embodiment of the present invention;

Fig. 17 is a MTF graph of 0.435 to 0.656 μm at the shortest focal length according to embodiment two of the present invention;

Fig. 18 is a defocus graph of 0.435-0.656 μm visible light at the shortest focal length according to the second embodiment of the present invention;

fig. 19 is an MTF graph of infrared 850nm at the shortest focal length according to the second embodiment of the present invention;

Fig. 20 is a defocus graph of 850nm infrared light at the shortest focal length according to the second embodiment of the present invention;

fig. 21 is a schematic view of curvature of field and distortion at the shortest focal length according to the second embodiment of the present invention;

fig. 22 is a schematic diagram of a color difference curve when the second embodiment of the present invention is at the shortest focal length;

fig. 23 is a schematic view of longitudinal aberration at the shortest focal length according to the second embodiment of the present invention;

Fig. 24 is a graph of MTF of 0.435-0.656 μm at the longest focal length according to embodiment two of the present invention;

Fig. 25 is a defocus graph of 0.435-0.656 μm visible light at the longest focal length according to embodiment two of the present invention;

fig. 26 is an MTF graph of infrared 850nm at the longest focal length according to the second embodiment of the present invention;

Fig. 27 is a defocus graph of 850nm infrared light at the longest focal length according to the second embodiment of the present invention;

Fig. 28 is a schematic view of curvature of field and distortion at the longest focal length according to the second embodiment of the present invention;

Fig. 29 is a schematic diagram of a chromatic aberration curve when the longest focal length is achieved according to the second embodiment of the present invention;

Fig. 30 is a schematic view of longitudinal aberration at the longest focal length according to the second embodiment of the present invention;

Fig. 31 is a MTF graph of 0.435-0.656 μm at the shortest focal length according to the third embodiment of the present invention;

Fig. 32 is a defocus graph of 0.435-0.656 μm visible light at the shortest focal length according to the third embodiment of the present invention;

Fig. 33 is an MTF graph of infrared 850nm at the shortest focal length according to the third embodiment of the present invention;

fig. 34 is a defocus graph of 850nm infrared light at the shortest focal length according to the third embodiment of the present invention;

Fig. 35 is a schematic view of curvature of field and distortion at the shortest focal length according to the third embodiment of the present invention;

Fig. 36 is a schematic view of a chromatic aberration curve diagram of the third embodiment of the present invention at the shortest focal length;

Fig. 37 is a schematic view of longitudinal aberration at the shortest focal length according to the third embodiment of the present invention;

Fig. 38 is a graph of MTF of 0.435-0.656 μm at the longest focal length according to embodiment three of the present invention;

fig. 39 is a defocus graph of 0.435-0.656 μm visible light at the longest focal length according to the third embodiment of the present invention;

Fig. 40 is an MTF graph of infrared 850nm at the longest focal length according to the third embodiment of the present invention;

fig. 41 is a defocus graph of 850nm infrared light at the longest focal length according to the third embodiment of the present invention;

fig. 42 is a schematic view of curvature of field and distortion at the longest focal length according to the third embodiment of the present invention;

Fig. 43 is a schematic diagram of a chromatic aberration curve when the longest focal length is achieved according to the third embodiment of the present invention;

fig. 44 is a schematic view of longitudinal aberration at the longest focal length according to the third embodiment of the present invention;

fig. 45 is a MTF graph of 0.435-0.656 μm at the shortest focal length according to embodiment four of the present invention;

fig. 46 is a defocus graph of 0.435-0.656 μm in visible light at the shortest focal length according to the fourth embodiment of the present invention;

fig. 47 is an MTF graph of infrared 850nm at the shortest focal length according to the fourth embodiment of the present invention;

Fig. 48 is a defocus graph of 850nm infrared light at the shortest focal length according to the fourth embodiment of the present invention;

fig. 49 is a schematic view of curvature of field and distortion at the shortest focal length according to the fourth embodiment of the present invention;

fig. 50 is a schematic view of a chromatic aberration curve diagram of the fourth embodiment of the present invention at the shortest focal length;

Fig. 51 is a schematic view of longitudinal aberration at the shortest focal length according to the fourth embodiment of the present invention;

fig. 52 is a graph of MTF of 0.435-0.656 μm at the longest focal length according to embodiment four of the present invention;

fig. 53 is a defocus graph of 0.435-0.656 μm visible light at the longest focal length according to the fourth embodiment of the present invention;

fig. 54 is an MTF graph of infrared 850nm at the longest focal length according to the fourth embodiment of the present invention;

fig. 55 is a graph of the defocus of 850nm in the infrared region at the longest focal length according to the fourth embodiment of the present invention;

Fig. 56 is a schematic view of curvature of field and distortion at the longest focal length according to the fourth embodiment of the present invention;

fig. 57 is a schematic diagram of a chromatic aberration curve when the longest focal length is set according to the fourth embodiment of the present invention;

fig. 58 is a diagram illustrating longitudinal aberrations at the longest focal length according to the fourth embodiment of the present invention;

fig. 59 is a MTF graph of 0.435-0.656 μm at the shortest focal length according to embodiment five of the present invention;

Fig. 60 is a defocus graph of 0.435-0.656 μm visible light at the shortest focal length according to embodiment v of the present invention;

Fig. 61 is an MTF graph of infrared 850nm at the shortest focal length according to embodiment five of the present invention;

Fig. 62 is a defocus graph of 850nm infrared light at the shortest focal length according to the embodiment of the present invention;

fig. 63 is a schematic view of curvature of field and distortion at the shortest focal length according to the fifth embodiment of the present invention;

fig. 64 is a schematic view of a chromatic aberration curve diagram of the fifth embodiment of the present invention at the shortest focal length;

Fig. 65 is a schematic view of longitudinal aberration at the shortest focal length according to embodiment five of the present invention;

fig. 66 is a graph of MTF of 0.435-0.656 μm at the longest focal length according to embodiment five of the present invention;

fig. 67 is a defocus graph of 0.435-0.656 μm visible light at the longest focal length according to embodiment v of the present invention;

fig. 68 is an MTF graph of infrared 850nm at the longest focal length according to embodiment v of the present invention;

fig. 69 is a defocus graph of 850nm infrared light at the longest focal length according to embodiment of the present invention;

Fig. 70 is a schematic view of curvature of field and distortion at the longest focal length according to embodiment five of the present invention;

Fig. 71 is a schematic diagram of a chromatic aberration curve when the longest focal length is achieved according to an embodiment of the present invention;

Fig. 72 is a diagram illustrating longitudinal aberrations at the longest focal length according to embodiment five of the present invention;

Detailed Description

The present invention will now be further described with reference to the accompanying drawings and detailed description.

the term "a lens element having positive refractive index (or negative refractive index)" means that the paraxial refractive index of the lens element calculated by Gaussian optics theory is positive (or negative). The term "object-side (or image-side) of a lens" is defined as the specific range of imaging light rays passing through the lens surface. The determination of the surface shape of the lens can be performed by the judgment method of a person skilled in the art, i.e., by the sign of the curvature radius (abbreviated as R value). The R value may be commonly used in optical design software, such as Zemax or CodeV. The R value is also commonly found in lens data sheets (lens sheets) of optical design software. When the R value is positive, the object side is judged to be a convex surface; and when the R value is negative, judging that the object side surface is a concave surface. On the contrary, regarding the image side surface, when the R value is positive, the image side surface is judged to be a concave surface; when the R value is negative, the image side surface is judged to be convex.

the utility model provides a zoom lens, which comprises a first lens, a fourth lens, a diaphragm, a fifth lens, a twelfth lens and a lens base from an object side to an image side along an optical axis in sequence; the first lens element to the twelfth lens element each include an object-side surface facing the object side and passing the image light and an image-side surface facing the image side and passing the image light.

The first lens element with negative refractive index has a convex object-side surface and a concave image-side surface; the second lens element with negative refractive index has a concave object-side surface and a concave image-side surface; the third lens element with negative refractive index has a concave object-side surface and a concave image-side surface; the fourth lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the image side surface of the third lens and the object side surface of the fourth lens are mutually glued; the first to fourth lenses constitute a focusing lens group.

The fifth lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the sixth lens element with positive refractive index has a convex object-side surface and a convex image-side surface; the seventh lens element with negative refractive index has a concave object-side surface and a convex image-side surface; the eighth lens element with positive refractive index has a concave object-side surface and a convex image-side surface; the ninth lens element with positive refractive power has a convex object-side surface and a convex image-side surface; the tenth lens element with a negative refractive index has a convex object-side surface and a concave image-side surface; the eleventh lens element with positive refractive power has a convex object-side surface and a convex image-side surface; the twelfth lens element with a negative refractive index has a concave object-side surface and a convex image-side surface; the image side surface of the sixth lens and the object side surface of the seventh lens are mutually glued; the image side surface of the eleventh lens and the object side surface of the twelfth lens are mutually glued; the fifth lens to the twelfth lens form a variable power lens group.

the object side surface and the image side surface of the fifth lens are both aspheric surfaces, so that large light transmission is realized, and the zoom lens only has the twelve lenses with the refractive index. The utility model adopts twelve lenses, and through the corresponding design of each lens, the low-light characteristic is good, and under the condition of poor light, clear color images can be realized; distortion is well controlled, the object image deformation is small, and the reducibility is strong; the transfer function is well controlled, the resolution is high, the image sharpness is high, and the images are uniform; the focal length span is large, the field angle span is large, and the switching flexibility is strong; and when visible light is emitted, the color difference management and control are better, and the color reducibility is good.

Preferably, the zoom lens further satisfies: 1.55< nd5<1.65, wherein nd5 respectively represents the refractive index of the fifth lens at the d line, the material has properties suitable for the aspheric surface processing technology, the refractive index of the material is not high, and the material with the low refractive index is relatively low in price under the condition of ensuring the imaging quality, so that the manufacturing cost can be reduced to a certain extent.

preferably, the zoom lens further satisfies: vd3-vd4>30, wherein vd3 and vd4 respectively represent the d-line abbe numbers of the third lens and the fourth lens, and are favorable for correcting chromatic aberration.

Preferably, the zoom lens further satisfies: 1.40< nd6<1.50, 85< vd6<95, 1.75< nd7<1.85, 20< vd7<30, and vd6-vd7>60, wherein nd6 and nd7 respectively represent refractive indexes of the sixth lens and the seventh lens at a d line, and vd6 and vd7 respectively represent dispersion coefficients of the sixth lens and the seventh lens at the d line, so that chromatic aberration can be corrected, infrared performance of the lens can be better guaranteed, and a blue confocal purple edge phenomenon can be well controlled.

preferably, the zoom lens further satisfies: vd11-vd12>40, wherein vd11 and vd12 respectively represent the abbe numbers of the eleventh lens and the twelfth lens at the d line, which is beneficial to correcting chromatic aberration.

more preferably, the zoom lens further satisfies: 1.50< nd11<1.60, 60< vd11<70, 1.9< nd12<2.0, and 20< vd12<30, wherein nd11 and nd12 respectively represent the refractive indexes of the eleventh lens and the twelfth lens on a d line, which is beneficial to further correcting chromatic aberration, better ensuring the infrared confocal performance of the lens, and also well controlling the blue-violet edge phenomenon, and the twelfth lens is made of a high-refractive-index material, so that the imaging quality of the zoom lens can be better improved.

The three groups of cemented lenses (the third lens and the fourth lens, the sixth lens and the seventh lens, and the eleventh lens and the twelfth lens) all adopt a matching mode of materials with larger dispersion coefficient difference values, so that chromatic aberration can be greatly reduced, the infrared confocal performance of the zoom lens can be better ensured, and the blue-violet edge phenomenon can be well controlled.

preferably, the zoom lens further satisfies: 0.4< fw/BFLw <0.6, wherein fw is the shortest focal length, BFLw is the back focal length when the shortest focal length is, so that the back focal length is longer, and the camera can be better adapted to various cameras.

preferably, the zoom lens further satisfies: 0.6< ft/BFLt <0.7, wherein ft is the longest focal length, BFLt is the back focal length when the longest focal length, so that the back focal length is longer, and the camera can be better adapted to various cameras.

preferably, the first lens to the twelfth lens are made of glass materials, so that the imaging quality of the zoom lens is further improved.

The zoom lens of the present invention will be described in detail with specific embodiments.

implement one

As shown in fig. 1 and 2, a zoom lens includes, in order along an optical axis I, a first lens 1 to a fourth lens 4, a stop 14, a fifth lens 5 to a twelfth lens 13, a flat glass 15, and an image plane 16 from an object side a1 to an image side a 2; the first lens element 1 to the twelfth lens element 13 each include an object-side surface facing the object side a1 and passing the image light, and an image-side surface facing the image side a2 and passing the image light.

the first lens element 1 has a negative refractive index, the object-side surface 101 of the first lens element 1 is a convex surface, and the image-side surface 102 of the first lens element 1 is a concave surface; the second lens element 2 has a negative refractive index, the object-side surface 201 of the second lens element 2 is concave, and the image-side surface 202 of the second lens element 2 is concave; the third lens element 3 has a negative refractive index, wherein an object-side surface 301 of the third lens element 3 is concave, and an image-side surface 302 of the third lens element 3 is concave; the fourth lens element 4 with positive refractive index has a convex object-side surface 401 of the fourth lens element 4 and a convex image-side surface 402 of the fourth lens element 4; the image side surface 302 of the third lens 3 and the object side surface 401 of the fourth lens 4 are mutually glued; the first to fourth lenses 1 to 4 constitute a focusing lens group.

The fifth lens element 5 with positive refractive index has a convex object-side surface 501 and a convex image-side surface 502 of the fifth lens element 5; the sixth lens element 6 with positive refractive index has a convex object-side surface 601 of the sixth lens element 6 and a convex image-side surface 602 of the sixth lens element 6; the seventh lens element 7 with negative refractive index has a concave object-side surface 701 of the seventh lens element 7 and a convex image-side surface 702 of the seventh lens element 7; the eighth lens element 8 with positive refractive index has a concave object-side surface 801 and a convex image-side surface 802 of the eighth lens element 8; the ninth lens element 9 with positive refractive index has a convex object-side surface 901 of the ninth lens element 9 and a convex image-side surface 902 of the ninth lens element 9; the tenth lens element 11 with negative refractive index has a convex object-side surface 111 of the tenth lens element 11 and a concave image-side surface 112 of the tenth lens element 11; the eleventh lens element 12 with positive refractive power has a convex object-side surface 121 of the eleventh lens element 12 and a convex image-side surface 122 of the eleventh lens element 12; the twelfth lens element 13 has a negative refractive index, the object-side surface 131 of the twelfth lens element 13 is concave, and the image-side surface 132 of the twelfth lens element 13 is convex; the image side 602 of the sixth lens 6 and the object side 701 of the seventh lens 7 are cemented with each other; the image side surface 122 of the eleventh lens 12 and the object side surface 131 of the twelfth lens 13 are cemented with each other; the fifth lens 5 to the twelfth lens 13 constitute a variable power lens group. The object-side surface 501 and the image-side surface 502 of the fifth lens element 5 are both aspheric.

Detailed optical data at the shortest focal length of this embodiment are shown in table 1-1.

TABLE 1-1 detailed optical data at shortest focal length of example one

Detailed optical data at the longest focal length for this particular embodiment are shown in tables 1-2.

TABLE 1-2 detailed optical data at longest focal length of example one

in this embodiment, the object-side surface 501 and the image-side surface 502 of the fifth lens element 5 are defined by the following aspheric curve formulas:

wherein:

z: depth of the aspheric surface (the vertical distance between a point on the aspheric surface that is y from the optical axis and a tangent plane tangent to the vertex on the optical axis of the aspheric surface);

c: the curvature of the aspheric vertex (thevertexc μ rvat μ re);

k: cone coefficient (Conicconstant);

radial distance (radialdistance);

r_n: normalized radius (normalizationradi μ S (NRADI μ S));

μ：r/r_n；

a_m: mth order Q^conCoefficient (isthem)^thQ^concoefficient)；

Q_m ^con: mth order Q^conpolynomial (then)^thQ^conpolynomial)；

For details of parameters of each aspheric surface, please refer to the following table:

surface of	501	502
			K＝	5.730264645	13.16026525
a₄	-7.352E-07	-6.765E-07
			a₆	-2.704E-08	-1.486E-08
a₈	-5.092E-12	-1.59E-10
			a₁₂	-4.72E-12	-1.795E-12

The image resolution of the present embodiment is shown in fig. 3, 5, 10 and 12, which shows that the optical transfer control is good, the resolution and the imaging quality are high, the confocal performance of visible light and infrared light is shown in fig. 4, 6, 11 and 13, the confocal performance of visible light and infrared light is good, the defocus amount is small when the visible infrared light is switched, the field curvature and distortion map is shown in (a) and (B) of fig. 7 and (a) and (B) of fig. 14, the chromatic aberration map is shown in fig. 8 and 15, the longitudinal aberration is shown in fig. 9 and 16, the distortion is small, the chromatic aberration is small, and the imaging quality is high.

In the specific embodiment, the focal length f of the zoom lens is 4.4-9.7 mm; the aperture value FNO is 1.25-1.88, the field angle FOV is 146 ° -51 °, Fw is 4.4mm, BFLw is 8.5mm, ft is 9.7mm, BFLt is 14.8mm, Fw/BFLw is 0.52, ft/BFLt is 0.66.

carry out two

in this embodiment, the surface convexoconcave and the refractive index of each lens are the same as those of the first embodiment, and only the optical parameters such as the curvature radius of the surface of each lens and the thickness of the lens are different.

the detailed optical data at the shortest focal length of this embodiment is shown in table 2-1.

TABLE 2-1 detailed optical data at shortest focal Length for example two

the detailed optical data at the longest focal length for this particular embodiment is shown in table 2-2.

TABLE 2-2 detailed optical data at longest focal Length for example two

For the detailed data of the parameters of each aspheric surface of this embodiment, refer to the following table:

surface of	501	502
			K＝	5.651140926	14.17304848
a₄	-7.211E-07	-6.625E-07
			a₆	-2.76742E-08	-1.47541E-08
a₈	2.65655E-11	-1.57542E-10
			a₁₂	-4.64664E-12	-1.49947E-12

The image resolution of the present embodiment is shown in fig. 17, 19, 24 and 26, which show that the image quality and resolution are good, the confocal performance of visible light and infrared light is good, the defocus amount is small when the visible infrared light is switched, the field curvature and distortion diagram is shown in (a) and (B) of fig. 21 and (a) and (B) of fig. 28, the chromatic aberration diagram is shown in fig. 22 and 29, the longitudinal aberration is shown in fig. 23 and 30, the distortion is small, the chromatic aberration is small, and the image quality is high.

in the specific embodiment, the focal length f of the zoom lens is 4.4-9.7 mm; the aperture value FNO is 1.22-1.87, the field angle FOV is 146 ° -51 °, Fw is 4.4mm, BFLw is 8.5mm, ft is 9.7mm, BFLt is 14.7mm, Fw/BFLw is 0.52, ft/BFLt is 0.66.

EXAMPLE III

The detailed optical data at the shortest focal length of this embodiment is shown in table 3-1.

TABLE 3-1 detailed optical data at shortest focal length for example III

the detailed optical data at the longest focal length of this embodiment is shown in table 3-2.

TABLE 3-2 detailed optical data at longest focal length for example III

The image resolution of the present embodiment is shown in fig. 31, 33, 38 and 40, which shows that the image quality and resolution are good, the confocal performance of visible light and infrared light is good, the defocus amount is small when the visible infrared light is switched, the field curvature and distortion map is shown in (a) and (B) of fig. 35 and (a) and (B) of fig. 42, the chromatic aberration map is shown in fig. 36 and 43, the longitudinal aberration is shown in fig. 37 and 44, the distortion is small, the chromatic aberration is small, and the image quality is high.

In the specific embodiment, the focal length f of the zoom lens is 4.4-9.7 mm; the aperture value FNO is 1.25-1.88, the field angle FOV is 146 ° -51 °, Fw is 4.4mm, BFLw is 8.3mm, ft is 9.7mm, BFLt is 14.5mm, Fw/BFLw is 0.53, ft/BFLt is 0.67.

example four

the detailed optical data at the shortest focal length of this embodiment is shown in table 4-1.

TABLE 4-1 detailed optical data at shortest focal length for example four

the detailed optical data at the longest focal length of this embodiment is shown in table 4-2.

TABLE 4-2 detailed optical data at longest focal length for example four

Surface of	501	502
			K＝	7.888565796	7.338088709
a₄	-6.61072E-07	-5.195E-07
			a₆	-1.772E-08	-9.39194E-09
a₈	-1.58673E-11	-1.05633E-10
			a₁₂	-6.14062E-12	-4.19387E-12

the image resolution of the present embodiment is shown in fig. 45, 47, 52 and 54, which shows that the image quality and resolution are good, the confocal performance of visible light and infrared light is good, the defocusing amount is small when the visible infrared light is switched, the field curvature and distortion map is shown in (a) and (B) of fig. 49 and (a) and (B) of fig. 56, the chromatic aberration map is shown in fig. 50 and 57, and the longitudinal aberration is shown in fig. 51 and 58, which shows that the distortion is small, the chromatic aberration is small, and the image quality is high.

In the specific embodiment, the focal length f of the zoom lens is 4.4-9.6 mm; the aperture value FNO is 1.25-1.89, the field angle FOV is 146 ° -51 °, Fw is 4.4mm, BFLw is 8.5mm, ft is 9.6mm, BFLt is 14.9mm, Fw/BFLw is 0.52, ft/BFLt is 0.64.

EXAMPLE five

the detailed optical data at the shortest focal length of this embodiment is shown in Table 5-1.

TABLE 5-1 detailed optical data at shortest focal Length for example five

The detailed optical data at the longest focal length of this embodiment is shown in table 5-2.

TABLE 5-2 detailed optical data at longest focal Length for EXAMPLE five

Surface of	501	502
			K＝	9.135557202	4.525701561
a₄	-6.072E-07	-7.24894E-07
			a₆	-1.5946E-08	-8.3E-10
a₈	1.65767E-10	-1.1714E-10
			a₁₂	-7.07517E-12	-3.77769E-12

The image resolution of the present embodiment is shown in fig. 59, 61, 66 and 68, which show that the image quality and resolution are good, the confocal performance of visible light and infrared light is good, the defocus amount is small when the visible infrared light is switched, the field curvature and distortion are shown in (a) and (B) of fig. 63 and (a) and (B) of fig. 70, the chromatic aberration is shown in fig. 64 and 71, the longitudinal aberration is shown in fig. 65 and 72, the distortion is small, the chromatic aberration is small, and the image quality is high.

In the specific embodiment, the focal length f of the zoom lens is 4.4-9.7 mm; the aperture value FNO is 1.25-1.85, the field angle FOV is 146 ° -51 °, Fw is 4.4mm, BFLw is 8.4mm, ft is 9.2mm, BFLt is 14.5mm, Fw/BFLw is 0.52, ft/BFLt is 0.63.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A zoom lens, characterized in that: the lens assembly comprises first to fourth lenses, a diaphragm and fifth to twelfth lenses in sequence from an object side to an image side along an optical axis; the first lens element to the twelfth lens element each include an object-side surface facing the object side and allowing the imaging light to pass therethrough and an image-side surface facing the image side and allowing the imaging light to pass therethrough;

2. a zoom lens according to claim 1, further satisfying: 1.55< nd5<1.65, where nd5 denotes the refractive index of the fifth lens at the d-line, respectively.

3. A zoom lens according to claim 1, further satisfying: vd3-vd4>30, where vd3 and vd4 denote the abbe numbers of the third and fourth lenses, respectively, in the d-line.

4. A zoom lens according to claim 1, further satisfying: 1.40< nd6<1.50, 85< vd6<95, 1.75< nd7<1.85, 20< vd7<30, vd6-vd7>60, wherein nd6 and nd7 respectively represent refractive indexes of the sixth lens and the seventh lens in a d line, and vd6 and vd7 respectively represent abbe numbers of the sixth lens and the seventh lens in the d line.

5. A zoom lens according to claim 1, further satisfying: vd11-vd12>40, where vd11 and vd12 represent the abbe numbers of the eleventh and twelfth lenses, respectively, in the d-line.

6. A zoom lens according to claim 5, further satisfying: 1.50< nd11<1.60, 60< vd11<70, 1.9< nd12<2.0, 20< vd12<30, where nd11 and nd12 respectively represent the refractive indices of the eleventh lens and the twelfth lens in the d-line.

7. A zoom lens according to claim 1, further satisfying: 0.4< fw/BFLw <0.6, wherein fw is the shortest focal length and BFLw is the back focal length at the shortest focal length.

8. a zoom lens according to claim 1, further satisfying: 0.6< ft/BFLt <0.7, where ft is the longest focal length and BFLt is the back focal length at the longest focal length.

9. The zoom lens according to claim 1, wherein: the first lens to the twelfth lens are made of glass materials.