Zoom lens

Abstract

The invention discloses a zoom lens, which comprises a first fixed lens group, a zoom lens group, a focusing lens group and a second fixed lens group, and is characterized in that the first fixed lens group has positive focal power, the zoom lens group has negative focal power, the focusing lens group has positive focal power, and the second fixed lens group has negative focal power. According to the zoom lens provided by the embodiment of the invention, a four-component structure is adopted, 11 lenses are used, the total optical length TTL of the zoom lens is enabled to meet the condition that TTL is less than or equal to 60mm by setting the number of the lenses in the four lens groups and further limiting the focal power matching of the four lens groups and the 11 lenses, high-performance imaging from 436nm to 656nm under a 1 / 2.7 ''target surface is realized, and the imaging quality is improved. And the F / # aperture number can reach 1.8-2.8, so that the high-image-quality zoom lens which is small in size, large in aperture and infrared confocal and can be matched with a 1 / .7 ''chip is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of optical devices, and in particular to a zoom lens. Background Art

[0002] In the security field, zoom lenses have been widely used due to their advantages such as long shooting distance, continuous and rapid magnification change, and the ability to achieve good shooting effects in different usage scenarios. With the development of technology, cameras are gradually moving towards miniaturization and refinement, which also puts more stringent requirements on mainstream zoom lenses.

[0003] Existing zoom lenses usually use 1 / 2.7” chips, which have problems such as small aperture, large size, and infrared non-confocality. Summary of the invention

[0004] The invention provides a zoom lens to realize a zoom lens with large aperture, small volume and infrared confocality.

[0005] The present invention provides a zoom lens, comprising a first fixed lens group, a variable magnification lens group, a focus lens group, and a second fixed lens group, which are sequentially arranged along an optical axis from an object plane to an image plane;

[0006] The first fixed lens group and the second fixed lens group are fixedly arranged, and the variable power lens group and the focus lens group are movably arranged along the optical axis direction;

[0007] The first fixed lens group has positive optical power, the variable power lens group has negative optical power, the focusing lens group has positive optical power, and the second fixed lens group has negative optical power;

[0008] The first fixed lens group includes a first lens and a second lens arranged in sequence from the object plane to the image plane; the first lens has a negative optical power, and the second lens has a positive optical power;

[0009] The zoom lens group includes a third lens, a fourth lens and a fifth lens arranged in sequence from the object plane to the image plane; the third lens has a negative optical power, the fourth lens has a negative optical power, and the fifth lens has a positive optical power;

[0010] The focusing lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens arranged in sequence from the object plane to the image plane; the sixth lens has a positive focal power, the seventh lens has a negative focal power, the eighth lens has a positive focal power, the ninth lens has a negative focal power, and the tenth lens has a positive focal power;

[0011] The second fixed lens group includes an eleventh lens; the eleventh lens has negative optical power.

[0012] Optionally, the focal length of the first fixed lens group is FG1, the focal length of the variable magnification lens group is FG2, the focal length of the focus lens group is FG3, the focal length of the second fixed lens group is FG4, and the focal length of the zoom lens at the telephoto end is FT;

[0013] 1.500≤FG1 / FT≤2.830;

[0014] -0.487≤FG2 / FT≤-0.296;

[0015] 0.369≤FG3 / FT≤0.559;

[0016] -10.014≤FG4 / FT≤-1.081.

[0017] Optionally, the first lens and the second lens form a first cemented lens group;

[0018] and / or,

[0019] The fourth lens and the fifth lens form a second cemented lens group;

[0020] and / or,

[0021] The seventh lens, the eighth lens and the ninth lens form a third cemented lens group.

[0022] Optionally, the maximum movable distance of the zoom lens group is D2, the maximum movable distance of the focus lens group is D3, the back focus of the zoom lens is BFL, and the total optical length of the zoom lens is TTL;

[0023] 2.082≤D2 / D3≤2.969;

[0024] 0.213≤D2 / TTL≤0.534;

[0025] 0.073≤BFL / TTL≤0.107.

[0026] Optionally, the fourth lens, the fifth lens, the tenth lens and the eleventh lens are all plastic aspherical lenses;

[0027] The first lens, the second lens, the third lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens are all glass spherical lenses.

[0028] Optionally, the refractive index of the seventh lens is Nd7, and the Abbe number of the sixth lens is Vd6; Nd7≥1.93; Vd6≥80.00.

[0029] Optionally, the maximum lens diameter in the first fixed lens group is ΦG1, and the total optical length of the zoom lens is TTL; 0.182≤ΦG1 / TTL≤0.341.

[0030] Optionally, the seventh lens, the eighth lens and the ninth lens form a third cemented lens group;

[0031] The focal length of the third cemented lens group is F3, and the focal length of the focusing lens group is FG3; 6.057≤|F3 / FG3|≤40.044.

[0032] Optionally, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT;

[0033] 3.500≤FT / FW≤6.000.

[0034] Optionally, the image plane size of the zoom lens is HI, and the total optical length of the zoom lens is TTL; 0.016≤HI / TTL≤0.138.

[0035] The zoom lens provided in the embodiment of the present invention adopts a four-component structure and uses 11 lenses. By setting the number of lenses in four lens groups and further limiting the focal length matching of the four lens groups and the 11 lenses, the total optical length TTL of the zoom lens satisfies TTL≤60mm, and high-performance imaging from 436nm to 656nm band is achieved under a 1 / 2.7″ target surface, and the aperture number F / # can reach 1.8-2.8, thereby realizing a high-image quality zoom lens with a small size, a large aperture, infrared confocality, and the ability to cooperate with a 1 / 2.7″ chip.

[0036] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 A schematic diagram of the structure of a zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of the structure of a zoom lens at the telephoto end provided by an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of the structure of another zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0041] Figure 4 A schematic diagram of the structure of another zoom lens at the telephoto end provided by an embodiment of the present invention;

[0042] Figure 5 A schematic diagram of the structure of another zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0043] Figure 6 A schematic diagram of the structure of another zoom lens at the telephoto end provided by an embodiment of the present invention;

[0044] Figure 7 A field curvature distortion diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end;

[0045] Figure 8 A field curvature distortion diagram of the zoom lens provided in the first embodiment of the present invention at the telephoto end;

[0046] Fig. 9 A light fan diagram of the zoom lens at the wide-angle end provided in the first embodiment of the present invention;

[0047] Fig.10 A light fan diagram of the zoom lens at the telephoto end provided by the first embodiment of the present invention;

[0048] Fig.11 A vertical axis chromatic aberration diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end;

[0049] Fig.12 A vertical axis chromatic aberration diagram of the zoom lens provided in the first embodiment of the present invention at the telephoto end;

[0050] Fig.13 A field curvature distortion diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end;

[0051] Fig.14 A field curvature distortion diagram of the zoom lens at the telephoto end provided by the second embodiment of the present invention;

[0052] Fig.15 A light fan diagram of the zoom lens at the wide-angle end provided in the second embodiment of the present invention;

[0053] Fig.16 A light fan diagram of the zoom lens at the telephoto end provided by the second embodiment of the present invention;

[0054] Fig.17 A vertical axis chromatic aberration diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end;

[0055] Fig.18 A vertical axis chromatic aberration diagram of the zoom lens provided in the second embodiment of the present invention at the telephoto end;

[0056] Fig.19 A field curvature distortion diagram of the zoom lens provided in Embodiment 3 of the present invention at the wide-angle end;

[0057] Fig. 20 A field curvature distortion diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention;

[0058] Fig.21 A light fan diagram of the zoom lens at the wide-angle end provided in the third embodiment of the present invention;

[0059] Fig. 22 A light fan diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention;

[0060] Fig.23 A vertical axis chromatic aberration diagram of the zoom lens provided in Embodiment 3 of the present invention at the wide-angle end;

[0061] Fig.24 This is a diagram of vertical axis chromatic aberration of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end. DETAILED DESCRIPTION

[0062] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0063] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0064] Figure 1 A schematic diagram of the structure of a zoom lens at the wide-angle end provided by an embodiment of the present invention, Figure 2A schematic diagram of the structure of a zoom lens at the telephoto end provided by an embodiment of the present invention; Figure 3 A schematic diagram of the structure of another zoom lens at the wide-angle end provided by an embodiment of the present invention, Figure 4 A schematic diagram of the structure of another zoom lens at the telephoto end provided by an embodiment of the present invention; Figure 5 A schematic diagram of the structure of another zoom lens at the wide-angle end provided by an embodiment of the present invention, Figure 6 A schematic diagram of the structure of another zoom lens at the telephoto end provided by an embodiment of the present invention; Figure 1-Figure 6 As shown, the zoom lens provided by the embodiment of the present invention includes a first fixed lens group G1, a variable power lens group G2, a focus lens group G3 and a second fixed lens group G4 which are arranged in sequence from the object plane to the image plane along the optical axis.

[0065] The first fixed lens group G1 and the second fixed lens group G4 are fixedly arranged, and the variable power lens group G2 and the focus lens group G3 are movable along the optical axis direction.

[0066] The first fixed lens group G1 has positive power, the zoom lens group G2 has negative power, the focus lens group G3 has positive power, and the second fixed lens group G4 has negative power.

[0067] The first fixed lens group G1 includes a first lens L1 and a second lens L2 arranged in sequence from the object plane to the image plane; the first lens L1 has a negative refractive power, and the second lens L2 has a positive refractive power.

[0068] The zoom lens group G2 includes a third lens L3, a fourth lens L4 and a fifth lens L5 which are arranged in sequence from the object plane to the image plane; the third lens L3 has negative refractive power, the fourth lens L4 has negative refractive power, and the fifth lens L5 has positive refractive power.

[0069] The focusing lens group G3 includes a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a tenth lens L10 which are arranged in sequence from the object plane to the image plane; the sixth lens L6 has positive refractive power, the seventh lens L7 has negative refractive power, the eighth lens L8 has positive refractive power, the ninth lens L9 has negative refractive power, and the tenth lens L10 has positive refractive power.

[0070] The second fixed lens group G4 includes an eleventh lens L11 having negative refractive power.

[0071] Specifically, Figure 1-Figure 6 As shown, the zoom lens provided by the embodiment of the present invention is arranged in sequence along the optical axis from the object side to the image side: a first fixed lens group G1 with positive optical focal length, a variable magnification lens group G2 with negative optical focal length, a focusing lens group G3 with positive optical focal length, and a second fixed lens group G4 with negative optical focal length.

[0072] The first fixed lens group G1 , the variable power lens group G2 , the focus lens group G3 , and the second fixed lens group G4 may be disposed in one lens barrel (not shown in the figure), but the present invention is not limited thereto.

[0073] Furthermore, the first fixed lens group G1 and the second fixed lens group G4 may be fixed in position in the lens barrel, so that the first fixed lens group G1 and the second fixed lens group G4 are immovable relative to the image plane.

[0074] The zoom lens group G2 and the focus lens group G3 can move back and forth along the optical axis in the lens barrel, wherein moving the zoom lens group G2 can achieve a zooming effect, and moving the focus lens group G3 can achieve a focusing effect. By changing the positions of the zoom lens group G2 and the focus lens group G3 on the optical axis, the zoom lens can be switched between the wide-angle end and the telephoto end.

[0075] Among them, in the process of achieving zooming by changing the positions of the zoom lens group G2 and the focus lens group G3 on the optical axis, the zoom lens is at the wide-angle end when the focal length is the shortest, and is at the telephoto end when the focal length is the longest. At the wide-angle end and the telephoto end, the zoom lens has different focal lengths and optical focal powers.

[0076] Specifically, the focal length is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam, and it characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal length, the stronger the ability to bend light, and the smaller the absolute value of the focal length, the weaker the ability to bend light. When the focal length is a positive number, the refraction of light is convergent; when the focal length is a negative number, the refraction of light is divergent. The focal length can be used to characterize a refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a lens, or can be used to characterize a system formed by multiple lenses (i.e., a lens group).

[0077] In the embodiment of the present invention, the optical focal length of the first fixed lens group G1 is positive, and the light can be converged to a certain extent; the optical focal length of the variable magnification lens group G2 is negative, so that after the light is initially converged by the first fixed lens group G1, it is appropriately diverged by the variable magnification lens group G2 to adjust the light path, ensure that the light can enter the subsequent structure, and better control the degree of contraction of the light in the subsequent structure to adapt to different focal length requirements.

[0078] Furthermore, the first fixed lens group G1, the variable power lens group G2, the focus lens group G3 and the second fixed lens group G4 adopt a positive-negative-positive-negative optical focal length combination, so that the light can be reasonably converged and diverged when passing through each lens group, ensuring that the light will not be deflected too much, but will pass smoothly through the entire lens system. At the same time, it can also ensure that the light has a larger aperture before entering the aperture. Even if the aperture opening is large, the light can pass smoothly without causing aberrations due to sudden contraction, thereby allowing the lens to work at a larger aperture, which is conducive to increasing the aperture of the lens.

[0079] Continue to refer Figure 1-Figure 6 The number of lenses with optical power in the first fixed lens group G1 may be 2, wherein the first fixed lens group G1 may be composed of a first lens L1 with negative optical power and a second lens L2 with positive optical power.

[0080] The first lens L1 has a negative optical power, which can expand the light beam of the incident light, so that more light can enter the subsequent lens group, thereby facilitating the realization of a larger aperture.

[0081] The second lens L2 has positive power, that is, a negative lens and a positive lens are combined, which is beneficial to controlling the light path so that it passes through the subsequent lens group more smoothly. At the same time, it also helps to offset the dispersion effects of each other and reduce chromatic aberration.

[0082] It should be noted that the first fixed lens group G1 can reduce the weight and volume of the lens by using a smaller number of lenses (2 lenses). At the same time, it can also reduce the number of air-glass interfaces that light passes through, thereby reducing reflection losses and improving overall light transmittance.

[0083] The number of lenses with optical power in the zoom lens group G2 may be three, wherein the zoom lens group G2 may be composed of a third lens L3 with negative optical power, a fourth lens L4 with negative optical power, and a fifth lens L5 with positive optical power.

[0084] The number of lenses with optical power in the focusing lens group G3 can be 5, wherein the focusing lens group G3 can be composed of a sixth lens L6 with positive optical power, a seventh lens L7 with negative optical power, an eighth lens L8 with positive optical power, a ninth lens L9 with negative optical power and a tenth lens L10 with positive optical power.

[0085] The number of lenses with optical power in the second fixed lens group G4 may be one, wherein the second fixed lens group G4 may consist of an eleventh lens L11 with negative optical power.

[0086] In the embodiment of the present invention, a four-component structure is adopted, 11 lenses are used, the number of lenses in the four lens groups is set, and the optical focal length matching of the four lens groups and the 11 lenses is further limited, so that the total optical length TTL of the zoom lens satisfies TTL≤60mm, and high-performance imaging from 436nm to 656nm band is achieved under a 1 / 2.7″ target surface, and the aperture number F / # can reach 1.8-2.8, thereby realizing a high-image quality zoom lens with a small size, large aperture, infrared confocality, and capable of cooperating with a 1 / 2.7″ chip.

[0087] As a feasible implementation method, continue to refer to Figure 1-Figure 6 In the first fixed lens group G1, the object-side surface of the first lens L1 is convex; the object-side surface of the second lens L2 is convex, and the image-side surface is concave.

[0088] In the variator lens group G2, the object-side surface of the third lens L3 is convex, and the image-side surface is concave; the object-side surface of the fourth lens L4 is concave; and the object-side surface of the fifth lens L5 is convex, and the image-side surface is convex.

[0089] In the focusing lens group G3, the object-side surface of the sixth lens L6 is convex, and the image-side surface is convex; the object-side surface of the seventh lens L7 is convex; the object-side surface of the eighth lens L8 is convex; the object-side surface of the ninth lens L9 is concave, and the image-side surface is concave; the object-side surface of the tenth lens L10 is convex, and the image-side surface is convex.

[0090] In the second fixed lens group G4, the object-side surface of the eleventh lens L11 is concave, and the image-side surface is convex.

[0091] Among them, the surface shape of the lens affects the propagation direction of light and determines how the light bends when passing through the lens, which in turn affects the maximum aperture and light transmittance of the lens, as well as the quality and characteristics of the imaging.

[0092] In this embodiment, by reasonably matching the surface shapes of the various lenses, while satisfying the optical power requirements of the various lenses and achieving the required optical performance indicators (such as small size, large aperture, infrared confocality), it is beneficial to further reduce the total optical length of the entire zoom lens, thereby realizing a miniaturized lens design. In addition, while ensuring a large aperture, the path of light passing through the entire zoom lens is made smoother, reducing unnecessary reflections and absorption, which is beneficial to improving light throughput and imaging quality.

[0093] Continue to refer Figure 1-Figure 6 As a feasible implementation, the zoom lens further includes a stop STO, and the stop STO is located in the optical path between the fifth lens L5 and the sixth lens L6.

[0094] Among them, the aperture STO is set in the optical path between the fifth lens L5 and the sixth lens L6, so that the aperture STO can be closer to the front end of the zoom lens, so as to control the distribution of light entering the subsequent lenses through the aperture STO to optimize aberrations such as astigmatism and coma, so that high-order aberrations are well controlled at the front end of the zoom lens, ensuring that while the image height is increased and the target surface is expanded at the rear end of the zoom lens, good imaging quality can be maintained at a large aperture, thereby meeting the usage requirements in more situations.

[0095] Continue to refer Figure 1-Figure 6 As a feasible implementation, the zoom lens may further include a flat glass P, which is located on the image side of the eleventh lens L11. The flat glass P can protect the photosensitive chip from dust and pollution, thereby ensuring the imaging effect of the zoom lens.

[0096] In some cases, the flat glass P may also be used to correct specific aberrations or filter out unnecessary light, which is not specifically limited in the embodiment of the present invention.

[0097] Among them, the photosensitive chip is used to convert the light signals collected by the zoom lens into electrical signals, which can then generate digital images or videos through a series of processing steps.

[0098] Continue to refer Figure 1-Figure 6 As a feasible implementation, the focal length of the first fixed lens group G1 is FG1, the focal length of the zoom lens group G2 is FG2, the focal length of the focus lens group G3 is FG3, the focal length of the second fixed lens group G4 is FG4, and the focal length of the zoom lens at the telephoto end is FT; wherein, 1.500≤FG1 / FT≤2.830; -0.487≤FG2 / FT≤-0.296; 0.369≤FG3 / FT≤0.559; -10.014≤FG4 / FT≤-1.081.

[0099] Among them, by further limiting the focal length of each lens group, it is possible to achieve a reasonable combination of the optical power of each lens, so that light can pass through the zoom lens more smoothly, and at the same time, the high-order aberrations of the zoom lens can be corrected to a greater extent, thereby improving the imaging quality while achieving a larger aperture.

[0100] Continue to refer Figure 1-Figure 6 As a feasible implementation manner, the first lens L1 and the second lens L2 form a first cemented lens group g1; and / or, the fourth lens L4 and the fifth lens L5 form a second cemented lens group g2; and / or, the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a third cemented lens group g3.

[0101] Among them, Figure 1-Figure 6As shown, gluing the first lens L1 and the second lens L2 together can minimize or eliminate chromatic aberration, so that the chromatic aberration of the zoom lens is fully corrected. At the same time, the air space between the first lens L1 and the second lens L2 can be effectively reduced, thereby further reducing the total optical length of the lens.

[0102] In addition, gluing the first lens L1 and the second lens L2 together can also reduce the air interface, thereby reducing the reflection loss, and can also reduce the number of assembly components between the first lens L1 and the second lens L2, simplifying the assembly procedure in the lens manufacturing process, reducing costs, and reducing the influence of lens tolerances such as tilt / eccentricity generated during the assembly process on the zoom lens, thereby improving the stability of the zoom lens.

[0103] Similarly, gluing the fourth lens L4 and the fifth lens L5 together, and / or gluing the seventh lens L7, the eighth lens L8 and the ninth lens L9 together, can also achieve the above beneficial effects, which will not be described in detail herein.

[0104] Continue to refer Figure 1-Figure 6 As a feasible implementation, the maximum movable distance of the zoom lens group G2 is D2, the maximum movable distance of the focus lens group G3 is D3, the back focus of the zoom lens is BFL, and the total optical length of the zoom lens is TTL; wherein, 2.082≤D2 / D3≤2.969; 0.213≤D2 / TTL≤0.534; 0.073≤BFL / TTL≤0.107.

[0105] The total length TTL of the zoom lens refers to the distance from the optical axis center of the object side of the first lens L1 to the image plane; the back focus BFL of the zoom lens refers to the distance from the optical axis center of the image side of the eleventh lens L11 to the image plane.

[0106] In this embodiment, the maximum movable distance D2 of the zoom lens group G2 is 2.082 to 2.969 times the maximum movable distance D3 of the focus lens group G3. During the zooming process, the zoom lens group G2 has a larger moving range, which can more effectively change the focal length, ensuring the rapid response of the zoom lens during the zooming process, so that the zoom lens can quickly adjust the focal length during the zooming process, and achieve rapid switching from wide angle to telephoto. The focus lens group G3 has a relatively small moving range, which can be used for fine-tuning the focus, ensuring the rapid response of the zoom lens during the focusing process, so that the zoom lens can quickly adjust the focus during the focusing process, thereby achieving fast and accurate focusing.

[0107] The maximum movable distance D2 of the zoom lens group G2 and the total optical length TTL of the zoom lens satisfy 0.213≤D2 / TTL≤0.534, ensuring that the zoom lens group G2 can move effectively during the zooming process to achieve the zoom function from wide angle to telephoto. At the same time, the movement of the zoom lens group G2 will not occupy too much of the total length of the lens, thereby helping to reduce the size of the lens.

[0108] By limiting the maximum movable distance ratio of the zoom lens group G2 in the lens, and the maximum movable distance ratio of the zoom lens group G2 and the focus lens group G3, the zoom lens can achieve a fast response zoom-focus function, ensuring that rapid adjustment can be achieved during the zoom and focus process. At the same time, the zoom lens can be made more compact and the total volume of the zoom lens can be reduced.

[0109] Optionally, by setting the back focus BFL and the total optical length TTL of the zoom lens to satisfy 0.073≤BFL / TTL≤0.107, it can be ensured that the overall length of the lens is minimized while maintaining good optical performance, and sufficient space can be provided for the rear end structure of the lens, ensuring good compatibility of the lens with various sensors and accessories (such as filters, protective glass, etc.).

[0110] As a feasible implementation manner, the fourth lens L4, the fifth lens L5, the tenth lens L10 and the eleventh lens L11 are all plastic aspherical lenses, and the first lens L1, the second lens L2, the third lens L3, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are all glass spherical lenses.

[0111] Specifically, the zoom lens provided by the embodiment of the present invention includes at least four aspherical lenses, which can correct the geometric aberrations of the zoom lens, such as spherical aberration, coma and astigmatism, so as to improve the imaging quality of the entire zoom lens.

[0112] Among them, at least one glass aspherical lens can be set in the zoom lens group G2, the focus lens group G3 and the second fixed lens group G4, so that the spherical aberration and higher-order aberrations of the above lens groups can be better corrected, which is beneficial to improving image quality and aperture, and optimizing lens volume and weight.

[0113] In the embodiment of the present invention, the fourth lens L4, the fifth lens L5, the tenth lens L10 and the eleventh lens L11 are aspherical lenses, so that the light can pass through the entire lens system more smoothly without excessive deflection. At the same time, it can also ensure that the light has a larger aperture before entering the aperture. Even if the aperture opening is large, the light can pass smoothly without generating aberrations due to sudden contraction, thereby allowing the lens to work at a larger aperture, which is conducive to increasing the aperture of the lens.

[0114] In addition, the fourth lens L4, the fifth lens L5, the tenth lens L10 and the eleventh lens L11 adopt aspherical lenses, which can also make the distribution of aspherical lenses in the zoom lens more uniform, so that aberrations can be effectively corrected in the entire zoom range, ensuring good imaging quality at different focal lengths. At the same time, the uniformly distributed aspherical lenses can better coordinate the optical performance of the entire lens system, reduce local aberration accumulation, and improve the overall imaging quality.

[0115] Furthermore, the first lens L1, the second lens L2, the third lens L3, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are all spherical lenses, which helps to reduce costs and is easy to manufacture.

[0116] In this embodiment, the aspherical lens adopts a plastic lens, which can reduce the lens cost and lighten the lens weight. The spherical lens adopts a glass lens, which can achieve higher transmittance, reduce the loss of light energy, and is conducive to better imaging effect in dark light environment; at the same time, the glass lens has the advantages of high hardness, strong wear resistance, long service life and not easily deformed by temperature, which can make the performance of the zoom lens more stable.

[0117] Among them, glass lenses and plastic lenses are used in combination, and the two types of materials, glass and plastic, can also be used to compensate for each other. By using glass lenses or plastic lenses in specific positions, the resolution of the lens can be better balanced.

[0118] As a feasible implementation manner, the refractive index of the seventh lens L7 is Nd7, and the Abbe number of the sixth lens L6 is Vd6; Nd7≥1.93, Vd6≥80.00.

[0119] Among them, the seventh lens L7 adopts a high refractive index material, which can enhance the light deflection ability and more effectively shrink the light of each field of view into the aperture at a smaller angle, thereby effectively reducing the aberrations related to the field of view.

[0120] Optionally, the sixth lens L6 is close to the aperture position, and the intersection points of the field light rays at different apertures of the lens are close. Therefore, this position is extremely beneficial to the correction of lens chromatic aberration. In this embodiment, the sixth lens L6 is made of a material with a large Abbe number, which can effectively reduce chromatic aberration and improve imaging quality.

[0121] As a feasible implementation, the maximum lens diameter in the first fixed lens group G1 is ΦG1, the total optical length of the zoom lens is TTL, and 0.182≤ΦG1 / TTL≤0.341.

[0122] The maximum lens diameter in the first fixed lens group G1 refers to the diameter of the largest lens in the first fixed lens group G1.

[0123] In this embodiment, by setting, the maximum lens diameter ΦG1 and the total optical length TTL in the first fixed lens group G1 satisfy 0.182≤ΦG1 / TTL≤0.341. While controlling the lens volume and making the lens more miniaturized, the field of view angle and the amount of light entering the lens can be maximized, the viewing angle range of the lens can be increased, and more light can be allowed to enter the lens, increasing the aperture, thereby obtaining better imaging effects under low light conditions and meeting the usage requirements under more stringent conditions.

[0124] Continue to refer Figure 1-Figure 6 As a feasible implementation manner, the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a third cemented lens group g3, the focal length of the third cemented lens group g3 is F3, and the focal length of the focusing lens group G3 is FG3; 6.057≤|F3 / FG3|≤40.044.

[0125] Among them, by controlling the ratio between the focal length of the third cemented lens group g3 composed of the seventh lens L7, the eighth lens L8 and the ninth lens L9 in the focusing lens group G3 and the focal length of the focusing lens group G3, the forward trend of light can be controlled to a large extent, aberrations and distortions can be reduced, and while ensuring the imaging quality, the target surface size of the zoom lens can be increased to a greater extent, so that the lens can adapt to sensors of different sizes and types and meet more chip usage requirements.

[0126] As a feasible implementation manner, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT; 3.500≤FT / FW≤6.000.

[0127] Among them, FT / FW can be understood as the zoom ratio. By limiting the ratio range between the focal length FW of the zoom lens at the wide-angle end and the focal length FT at the telephoto end, the zoom range and focal length range of the lens can be controlled, so that the lens can meet the usage requirements under more conditions.

[0128] As a feasible implementation, the image plane size of the zoom lens is HI, the total optical length of the zoom lens is TTL, and 0.016≤HI / TTL≤0.138.

[0129] The image plane size can be understood as the image plane diagonal length or the image plane diameter.

[0130] In this embodiment, the image plane size HI and the total optical length TTL of the zoom lens are set to satisfy 0.016≤HI / TTL≤0.138, which can control the volume of the zoom lens to a greater extent and achieve a miniaturized design. At the same time, the image plane size can be enlarged, thereby achieving the effect of compressing the volume and expanding the target surface.

[0131] Specific embodiments of the zoom lens applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0132] Embodiment 1

[0133] like Figure 1 and Figure 2 As shown, the zoom lens provided by the first embodiment of the present invention comprises a first fixed lens group G1, a variable power lens group G2, a focus lens group G3 and a second fixed lens group G4 which are arranged in sequence from the object plane to the image plane along the optical axis.

[0134] The first fixed lens group G1 includes a first lens L1 and a second lens L2 arranged in sequence from the object plane to the image plane. The zoom lens group G2 includes a third lens L3, a fourth lens L4 and a fifth lens L5 arranged in sequence from the object plane to the image plane. The focus lens group G3 includes a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a tenth lens L10 arranged in sequence from the object plane to the image plane. The second fixed lens group G4 includes an eleventh lens L11.

[0135] The first lens L1 and the second lens L2 form a first cemented lens group g1; the fourth lens L4 and the fifth lens L5 form a second cemented lens group g2; the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a third cemented lens group g3.

[0136] The aperture STO is located in the optical path between the fifth lens L5 and the sixth lens L6, and the plate glass P is located on the image-side surface of the eleventh lens L11.

[0137] Table 1 describes in detail the specific optical and physical parameters of each lens in the zoom lens provided in Example 1 of the present invention in a feasible implementation manner. The zoom lens in Table 1 corresponds to Figure 1 and Figure 2 Zoom lens shown.

[0138] Table 1 Design values ​​of optical physical parameters of zoom lens

[0139] Surface number Surface type Radius of curvature thickness Materials (n.d.) Material (vd) 1 Standard surface 23.6711 0.6159 1.84 22.45 2 Standard surface 17.5783 4.5439 1.81 63.71 3 Standard surface 66.5640 0.0000 4 Standard surface INF 16.0748 5 Standard surface INF Zoom interval 1 6 Standard surface 30.0935 0.3295 1.96 62.05 7 Standard surface 6.0371 4.0363 8 Aspheric -20.4242 1.2997 1.54 41.14 9 Aspheric 16.2710 2.3898 1.66 23.33 10 Aspheric -39.5584 Zoom interval 2 11 STO INF Zoom interval 3 12 Standard surface 15.3901 1.0000 1.73 80.00 13 Standard surface -77.8386 0.0500 14 Standard surface 6.3747 2.1812 1.95 39.05 15 Standard surface 3.8631 3.2767 1.50 86.80 16 Standard surface -8.6521 1.0422 1.72 31.64 17 Standard surface 17.3384 0.6047 18 Aspheric 28.3898 1.3900 1.54 37.70 19 Aspheric -13.1648 Zoom interval 4 20 Standard surface INF 7.5888 21 Aspheric -5.9659 1.1203 1.53 52.33 22 Aspheric -6.9018 1.8431 23 Standard surface INF 0.7100 1.52 64.20 24 Standard surface INF 2.5558 25 IMA - -

[0140] The surface numbers in Table 1 are numbered according to the order of the surfaces of each lens, where "1" represents the object side of the first lens, "2" represents the image side of the first lens, and so on; "STO" represents the aperture of the zoom lens; the radius of curvature represents the degree of curvature of the corresponding lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, where "INF" indicates that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the material (nd) is the refractive index, which represents the light deflection ability of the material between the current surface and the next surface, and a blank space represents that the current position is air with a refractive index of 1; the material (vd) is the Abbe number, which represents the dispersion characteristics of the light between the current surface and the next surface, and a blank space represents that the current position is air; "IMA" represents the image surface of the zoom lens.

[0141] Table 2 shows the values ​​of zoom intervals of the zoom lens in Table 1 at the wide-angle end and the telephoto end.

[0142] Table 2 Design values ​​of zoom intervals of zoom lenses

[0143] Wide angle Telephoto end Zoom interval 1 -15.8976 -0.5329 Zoom interval 2 15.8976 0.5329 Zoom interval 3 6.3273 0.5803 Zoom interval 4 -6.3273 -0.5803

[0144] In this embodiment, the aspheric cone coefficient of the aspheric lens in the zoom lens can be defined by the following aspheric formula, but is not limited to the following expression method:

[0145]

[0146] Among them, z is the axial vector height of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitted sphere, which is the inverse of the radius of curvature; k is the fitted cone coefficient; AI is the coefficient of the 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, and 20th order terms of the aspheric polynomial.

[0147] Exemplarily, Table 3 describes in detail the aspheric cone coefficients of each lens in the first embodiment in a feasible implementation manner.

[0148] Table 3 Design values ​​of aspheric cone coefficients of each lens in the zoom lens

[0149]

[0150]

[0151] The K value in Table 3 represents the numerical value of the best fitting cone coefficient of the aspheric surface.

[0152] The zoom lens of the first embodiment can achieve the following technical indicators:

[0153] Table 4 Technical specifications of zoom lenses

[0154] Wide angle Telephoto end Image size(mm) Φ6.9 Φ6.9 Focal length(mm) 4.0661 22.4692 Aperture number F / # 1.816 2.862 Total optical length (mm) 52.653 52.653

[0155] Figure 7 This is a field curvature distortion diagram of the zoom lens provided in Embodiment 1 of the present invention at the wide-angle end. Figure 8 This is a field curvature distortion diagram of the zoom lens provided in the first embodiment of the present invention at the telephoto end. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, without units, where T represents the meridian and S represents the arc loss. In the right coordinate system of the figure, the horizontal coordinate represents the magnitude of the distortion (F-Tan(Theta)), in units of %; the vertical coordinate represents the normalized image height, without units. Figure 7 The maximum field of view is 44.217 degrees. Figure 8 The maximum field of view is 8.323 degrees. Figure 7 and Figure 8 It can be seen that the field curvature of the zoom lens provided in this embodiment is effectively controlled at the wide-angle end and the telephoto end, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small. At the same time, the distortion of the zoom lens at the wide-angle end and the telephoto end is also well corrected.

[0156] Fig. 9 This is a light fan diagram of the zoom lens at the wide-angle end provided in the first embodiment of the present invention. Fig.10 This is a light fan diagram of the zoom lens at the telephoto end provided in Example 1 of the present invention. In the diagram, the horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane, and the corresponding interval on the vertical axis of the curve is the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Fig. 9 and Fig.10 It can be seen that each wavelength of the zoom lens in each field of view is well aligned with the horizontal axis, indicating that the vertical axis aberration of each wavelength is well corrected. At the same time, the curves of each wavelength do not have obvious dispersion, indicating that the chromatic aberration of the zoom lens at the wide-angle end and the telephoto end is also well corrected, thereby being able to meet high-resolution imaging requirements.

[0157] Fig.11 The vertical axis chromatic aberration diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end is shown in FIG. Fig.12 This is a vertical axis chromatic aberration diagram of the zoom lens provided in the first embodiment of the present invention at the telephoto end, wherein the vertical direction represents the normalization of the field of view, and 0 represents the optical axis; the main wavelength uses 546nm, and the horizontal direction represents the offset relative to the main wavelength, in micrometers (μm). Fig.11 and Fig.12 The maximum field of view is 3.45 mm. Fig.11 and Fig.12 It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a good range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end and the telephoto end is well controlled and can meet the needs of wide-spectrum applications.

[0158] Embodiment 2

[0159] like Figure 3 and Figure 4 As shown, the zoom lens provided by the second embodiment of the present invention comprises a first fixed lens group G1, a variable power lens group G2, a focus lens group G3 and a second fixed lens group G4 which are arranged in sequence from the object plane to the image plane along the optical axis.

[0160] The first fixed lens group G1 includes a first lens L1 and a second lens L2 arranged in sequence from the object plane to the image plane. The zoom lens group G2 includes a third lens L3, a fourth lens L4 and a fifth lens L5 arranged in sequence from the object plane to the image plane. The focus lens group G3 includes a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a tenth lens L10 arranged in sequence from the object plane to the image plane. The second fixed lens group G4 includes an eleventh lens L11.

[0161] The first lens L1 and the second lens L2 form a first cemented lens group g1; the fourth lens L4 and the fifth lens L5 form a second cemented lens group g2; the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a third cemented lens group g3.

[0162] The aperture STO is located in the optical path between the fifth lens L5 and the sixth lens L6, and the plate glass P is located on the image-side surface of the eleventh lens L11.

[0163] Table 5 describes in detail the specific optical and physical parameters of each lens in the zoom lens provided in Example 2 of the present invention in a feasible implementation manner. The zoom lens in Table 5 corresponds to Figure 3 and Figure 4 Zoom lens shown.

[0164] Table 5 Design values ​​of optical physical parameters of zoom lens

[0165] Surface number Surface type Radius of curvature thickness Materials (n.d.) Material (vd) 1 Standard surface 24.0383 1.6475 1.86 19.90 2 Standard surface 14.2552 4.8156 1.80 36.08 3 Standard surface 63.1145 -0.0001 4 Standard surface INF 14.9762 5 Standard surface INF Zoom interval 1 6 Standard surface 29.1295 0.9706 1.96 80.66 7 Standard surface 6.0565 4.0024 8 Aspheric -20.4815 1.3900 1.54 80.99 9 Aspheric 16.3505 2.4994 1.66 88.63 10 Aspheric -38.8396 Zoom interval 2 11 STO INF Zoom interval 3 12 Standard surface 15.3931 1.2687 1.73 90.22 13 Standard surface -77.8307 0.1849 14 Standard surface 6.3770 2.1829 1.95 53.45 15 Standard surface 3.8617 3.2914 1.50 96.30 16 Standard surface -8.7975 0.9224 1.72 49.87 17 Standard surface 17.3480 0.6481 18 Aspheric 27.7273 1.5005 1.54 85.69 19 Aspheric -13.1135 Zoom interval 4 20 Standard surface INF 7.6642 21 Aspheric -5.4938 0.7097 1.53 22.36 22 Aspheric -6.9596 1.9320 23 Standard surface INF 0.6500 1.52 64.20 24 Standard surface INF 2.7710 25 IMA - -

[0166] The surface numbers in Table 5 are numbered according to the order of the surfaces of each lens, where "1" represents the object side of the first lens, "2" represents the image side of the first lens, and so on; "STO" represents the aperture of the zoom lens; the radius of curvature represents the degree of curvature of the corresponding lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, where "INF" indicates that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the material (nd) is the refractive index, which represents the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air with a refractive index of 1; the material (vd) is the Abbe number, which represents the dispersion characteristics of the material between the current surface and the next surface to light, and a blank space represents that the current position is air; "IMA" represents the image surface of the zoom lens.

[0167] Table 6 shows the values ​​of the zoom intervals of the zoom lens in Table 5 at the wide-angle end and the telephoto end.

[0168] Table 6 Design values ​​of zoom intervals of zoom lenses

[0169] Wide angle Telephoto end Zoom interval 1 -14.8110 -0.3550 Zoom interval 2 14.8110 0.3550 Zoom interval 3 6.3589 0.2792 Zoom interval 4 -6.3589 -0.2792

[0170] In this embodiment, the aspheric cone coefficient of the aspheric lens in the zoom lens can be defined by the following aspheric formula, but is not limited to the following expression method:

[0171]

[0172] Among them, z is the axial vector height of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitted sphere, which is the inverse of the radius of curvature; k is the fitted cone coefficient; AI is the coefficient of the 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, and 20th order terms of the aspheric polynomial.

[0173] Exemplarily, Table 7 describes in detail the aspheric cone coefficient of each lens in the second embodiment in a feasible implementation manner.

[0174] Table 7 Design values ​​of aspheric cone coefficients of each lens in the zoom lens

[0175]

[0176]

[0177] The K value in Table 7 represents the numerical value of the best fitting cone coefficient of the aspheric surface.

[0178] The zoom lens of the second embodiment can achieve the following technical indicators:

[0179] Table 8 Technical specifications of zoom lenses

[0180] Wide angle Telephoto end Image size(mm) Φ7.0 Φ7.0 Focal length(mm) 4.562 22.525 Aperture number F / # 1.819 2.895 Total optical length (mm) 54.028 54.028

[0181] Fig.13 This is a field curvature distortion diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end. Fig.14 This is a field curvature distortion diagram of the zoom lens provided in the second embodiment of the present invention at the telephoto end. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, without units, where T represents the meridian and S represents the arc loss. In the right coordinate system of the figure, the horizontal coordinate represents the magnitude of the distortion (F-Tan(Theta)), in units of %; the vertical coordinate represents the normalized image height, without units. Fig.13 The maximum field of view is 43.345 degrees. Fig.14 The maximum field of view is 8.738 degrees. Fig.13 and Fig.14 It can be seen that the field curvature of the zoom lens provided in this embodiment is effectively controlled at the wide-angle end and the telephoto end, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small. At the same time, the distortion of the zoom lens at the wide-angle end and the telephoto end is also well corrected.

[0182] Fig.15 This is a light fan diagram of the zoom lens at the wide-angle end provided by the second embodiment of the present invention, Fig.16 The light fan diagram of the zoom lens at the telephoto end provided in the second embodiment of the present invention. In the diagram, the horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane, and the corresponding interval on the vertical axis of the curve is the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Fig.15 and Fig.16 It can be seen that each wavelength of the zoom lens in each field of view is well aligned with the horizontal axis, indicating that the vertical axis aberration of each wavelength is well corrected. At the same time, the curves of each wavelength do not have obvious dispersion, indicating that the chromatic aberration of the zoom lens at the wide-angle end and the telephoto end is also well corrected, thereby being able to meet high-resolution imaging requirements.

[0183] Fig.17 The vertical axis chromatic aberration diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end is shown in FIG. Fig.18 This is a vertical axis chromatic aberration diagram of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention, wherein the vertical direction represents the normalization of the field of view, and 0 represents the optical axis; the main wavelength uses 546nm, and the horizontal direction represents the offset relative to the main wavelength, in micrometers (μm). Fig.17 and Fig.18 The maximum field of view is 3.5 mm. Fig.17 and Fig.18 It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a good range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end and the telephoto end is well controlled and can meet the needs of wide-spectrum applications.

[0184] Embodiment 3

[0185] like Figure 5 and Figure 6 As shown, the zoom lens provided by the third embodiment of the present invention comprises a first fixed lens group G1, a variable power lens group G2, a focus lens group G3 and a second fixed lens group G4 which are arranged in sequence from the object plane to the image plane along the optical axis.

[0186] The first fixed lens group G1 includes a first lens L1 and a second lens L2 arranged in sequence from the object plane to the image plane. The zoom lens group G2 includes a third lens L3, a fourth lens L4 and a fifth lens L5 arranged in sequence from the object plane to the image plane. The focus lens group G3 includes a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a tenth lens L10 arranged in sequence from the object plane to the image plane. The second fixed lens group G4 includes an eleventh lens L11.

[0187] The first lens L1 and the second lens L2 form a first cemented lens group g1; the fourth lens L4 and the fifth lens L5 form a second cemented lens group g2; the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a third cemented lens group g3.

[0188] The aperture STO is located in the optical path between the fifth lens L5 and the sixth lens L6, and the plate glass P is located on the image-side surface of the eleventh lens L11.

[0189] Table 9 describes in detail the specific optical and physical parameters of each lens in the zoom lens provided in Example 3 of the present invention in a feasible implementation manner. The zoom lens in Table 9 corresponds to Figure 5 and Figure 6 Zoom lens shown.

[0190] Table 9 Design values ​​of optical physical parameters of zoom lens

[0191] Surface number Surface type Radius of curvature thickness Materials (n.d.) Material (vd) 1 Standard surface 23.9988 0.4278 1.86 46.46 2 Standard surface 15.6888 4.8680 1.80 94.62 3 Standard surface 60.1227 0.2145 4 Standard surface INF 16.0957 5 Standard surface INF Zoom interval 1 6 Standard surface 30.2405 0.4319 1.97 84.25 7 Standard surface 5.9856 3.9994 8 Aspheric -19.6472 1.2642 1.48 94.86 9 Aspheric 16.3429 2.3422 1.70 47.98 10 Aspheric -40.5014 Zoom interval 2 11 STO INF Zoom interval 3 12 Standard surface 15.5655 2.3061 1.72 95.00 13 Standard surface -70.0000 0.5743 14 Standard surface 6.4036 2.1477 1.97 45.54 15 Standard surface 3.8284 3.2853 1.49 95.00 16 Standard surface -8.2550 1.2273 1.73 40.31 17 Standard surface 16.3806 0.6145 18 Aspheric 30.6117 1.3931 1.63 54.50 19 Aspheric -13.2783 Zoom interval 4 20 Standard surface INF 7.6108 21 Aspheric -5.5902 1.3154 1.51 90.00 22 Aspheric -6.9021 2.0436 23 Standard surface INF 0.7100 1.52 64.20 24 Standard surface INF 2.9418 25 IMA - -

[0192] The surface numbers in Table 9 are numbered according to the order of the surfaces of each lens, where "1" represents the object side of the first lens, "2" represents the image side of the first lens, and so on; "STO" represents the aperture of the zoom lens; the radius of curvature represents the degree of curvature of the corresponding lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, where "INF" indicates that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the material (nd) is the refractive index, which represents the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air with a refractive index of 1; the material (vd) is the Abbe number, which represents the dispersion characteristics of the material between the current surface and the next surface to light, and a blank space represents that the current position is air; "IMA" represents the image surface of the zoom lens.

[0193] Table 10 shows the values ​​of the zoom intervals of the zoom lens in Table 9 at the wide-angle end and the telephoto end.

[0194] Table 10 Design values ​​of zoom intervals of zoom lenses

[0195] Wide angle Telephoto end Zoom interval 1 -14.5910 -0.4950 Zoom interval 2 14.5910 0.4950 Zoom interval 3 6.3323 0.8972 Zoom interval 4 -6.3323 -0.8972

[0196] In this embodiment, the aspheric cone coefficient of the aspheric lens in the zoom lens can be defined by the following aspheric formula, but is not limited to the following expression method:

[0197]

[0198] Among them, z is the axial vector height of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitted sphere, which is the inverse of the radius of curvature; k is the fitted cone coefficient; AI is the coefficient of the 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, and 20th order terms of the aspheric polynomial.

[0199] Exemplarily, Table 11 describes in detail the aspheric cone coefficients of each lens in the third embodiment in a feasible implementation manner.

[0200] Table 11 Design values ​​of aspheric cone coefficients of each lens in zoom lens

[0201]

[0202]

[0203] The K value in Table 11 represents the numerical value of the best fitting cone coefficient of the aspheric surface.

[0204] The zoom lens of the third embodiment can achieve the following technical indicators:

[0205] Table 12 Technical specifications of zoom lenses

[0206] Wide angle Telephoto end Image size(mm) Φ6.9 Φ6.9 Focal length(mm) 5.024 21.002 Aperture number F / # 1.883 2.912 Total optical length (mm) 55.814 55.814

[0207] Fig.19 This is a field curvature distortion diagram of the zoom lens provided in Embodiment 3 of the present invention at the wide-angle end. Fig. 20 This is a field curvature distortion diagram of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, without units, where T represents the meridian and S represents the arc loss. In the right coordinate system of the figure, the horizontal coordinate represents the magnitude of the distortion (F-Tan(Theta)), in units of %; the vertical coordinate represents the normalized image height, without units. Fig.19 The maximum field of view is 38.486 degrees. Fig. 20 The maximum field of view is 9.229 degrees. Fig.19 and Fig. 20 It can be seen that the field curvature of the zoom lens provided in this embodiment is effectively controlled at the wide-angle end and the telephoto end, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small. At the same time, the distortion of the zoom lens at the wide-angle end and the telephoto end is also well corrected.

[0208] Fig.21 This is a light fan diagram of the zoom lens at the wide-angle end provided in the third embodiment of the present invention. Fig. 22 This is a light fan diagram of the zoom lens at the telephoto end provided in Example 3 of the present invention. In the diagram, the horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane, and the corresponding interval on the vertical axis of the curve is the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Fig.21 and Fig. 22 It can be seen that each wavelength of the zoom lens in each field of view is well aligned with the horizontal axis, indicating that the vertical axis aberration of each wavelength is well corrected. At the same time, the curves of each wavelength do not have obvious dispersion, indicating that the chromatic aberration of the zoom lens at the wide-angle end and the telephoto end is also well corrected, thereby being able to meet high-resolution imaging requirements.

[0209] Fig.23 This is a vertical axis chromatic aberration diagram of the zoom lens provided in the third embodiment of the present invention at the wide-angle end, Fig.24 This is a vertical axis chromatic aberration diagram of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end, wherein the vertical direction represents the normalization of the field of view, and 0 represents the optical axis; the main wavelength uses 546nm, and the horizontal direction represents the offset relative to the main wavelength, in micrometers (μm). Fig.23 and Fig.24 The maximum field of view is 3.45 mm. Fig.23and Fig.24 It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a good range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end and the telephoto end is well controlled and can meet the needs of wide-spectrum applications.

[0210] In order to explain the above embodiments more clearly, Table 13 details the specific optical and physical parameters of each lens in the zoom lens provided in Embodiments 1 to 3 of the present invention.

[0211] Table 13 Design values ​​of optical physical parameters of zoom lens

[0212] Embodiment 1 Embodiment 2 Embodiment 3 FG1 / FT 1.943 2.171 2.387 FG2 / FT -0.360 -0.376 -0.424 FG3 / FT 0.432 0.435 0.496 FG4 / FT -6.316 -2.617 -4.156 D2 / D3 2.674 2.378 2.594 D2 / TTL 0.292 0.268 0.253 BFL / TTL 0.097 0.099 0.102 Nd7 1.95 1.95 1.97 Vd6 80.00 90.22 95.00 ΦG1 / TTL 0.202 0.221 0.205 |F3 / FG3| 28.715 26.004 17.386 FT / FW 5.526 4.938 4.181 HI / TTL 0.131 0.130 0.124

[0213] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A zoom lens, characterized in that: It includes a first fixed lens group, a zoom lens group, a focus lens group, and a second fixed lens group which are arranged in sequence from the object plane to the image plane along the optical axis; The first fixed lens group and the second fixed lens group are fixedly arranged, and the variable power lens group and the focus lens group are movably arranged along the optical axis direction; The first fixed lens group has positive optical power, the variable power lens group has negative optical power, the focusing lens group has positive optical power, and the second fixed lens group has negative optical power; The first fixed lens group includes a first lens and a second lens arranged in sequence from the object plane to the image plane; the first lens has a negative optical power, and the second lens has a positive optical power; The zoom lens group includes a third lens, a fourth lens and a fifth lens arranged in sequence from the object plane to the image plane; the third lens has a negative optical power, the fourth lens has a negative optical power, and the fifth lens has a positive optical power; The focusing lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens arranged in sequence from the object plane to the image plane; the sixth lens has a positive focal power, the seventh lens has a negative focal power, the eighth lens has a positive focal power, the ninth lens has a negative focal power, and the tenth lens has a positive focal power; The second fixed lens group includes an eleventh lens; the eleventh lens has negative optical power.

2. The zoom lens according to claim 1, wherein: The focal length of the first fixed lens group is FG1, the focal length of the variable magnification lens group is FG2, the focal length of the focus lens group is FG3, the focal length of the second fixed lens group is FG4, and the focal length of the zoom lens at the telephoto end is FT; 1.500≤FG1 / FT≤2.830; -0.487≤FG2 / FT≤-0.296; 0.369≤FG3 / FT≤0.559; -10.014≤FG4 / FT≤-1.

081.

3. The zoom lens according to claim 1, wherein: The first lens and the second lens form a first cemented lens group; and / or, The fourth lens and the fifth lens form a second cemented lens group; and / or, The seventh lens, the eighth lens and the ninth lens form a third cemented lens group.

4. The zoom lens according to claim 1, wherein: The maximum movable distance of the zoom lens group is D2, the maximum movable distance of the focus lens group is D3, the back focus of the zoom lens is BFL, and the total optical length of the zoom lens is TTL; 2.082≤D2 / D3≤2.969; 0.213≤D2 / TTL≤0.534; 0.073≤BFL / TTL≤0.

107.

5. The zoom lens according to claim 1, wherein: The fourth lens, the fifth lens, the tenth lens and the eleventh lens are all plastic aspherical lenses; The first lens, the second lens, the third lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens are all glass spherical lenses.

6. The zoom lens according to claim 1, wherein: The refractive index of the seventh lens is Nd7, and the Abbe number of the sixth lens is Vd6; Nd7≥1.93; Vd6≥80.

00.

7. The zoom lens according to claim 1, wherein: The maximum lens diameter in the first fixed lens group is ΦG1, and the total optical length of the zoom lens is TTL; 0.182≤ΦG1 / TTL≤0.

341.

8. The zoom lens according to claim 1, wherein: The seventh lens, the eighth lens and the ninth lens form a third cemented lens group; The focal length of the third cemented lens group is F3, and the focal length of the focusing lens group is FG3; 6.057≤|F3 / FG3|≤40.

044.

9. The zoom lens according to claim 1, wherein: The focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT; 3.500≤FT / FW≤6.

000.

10. The zoom lens according to claim 1, wherein: The image plane size of the zoom lens is HI, and the total optical length of the zoom lens is TTL; 0.016≤HI / TTL≤0.138.

Images