Zoom lens

Abstract

The application discloses a zoom lens, which comprises a first fixed lens group, a variable magnification lens group, a focusing lens group and a second fixed lens group, the first fixed lens group has positive refractive power, the variable magnification lens group has negative refractive power, the focusing lens group has positive refractive power, and the second fixed lens group has negative refractive power. The zoom lens provided by the embodiment of the application adopts a four-group-element structure, uses 11 lenses, sets the number of lenses in the four lens groups, and further limits the refractive power matching of the four lens groups and the 11 lenses, so that the total optical length TTL of the zoom lens satisfies TTL <= 60mm, high-performance imaging from a 436nm to 656nm waveband on a 1 / 2.7" target surface is realized, the F / # can reach 1.8-2.8, and thus a high-image-quality zoom lens with small volume, large aperture and infrared confocal is realized, which can be matched with a 1 / 2.7" chip.

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 sophistication, which also puts more stringent requirements on mainstream zoom lenses.

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

[0004] The present invention provides a zoom lens to realize a zoom lens with large aperture, small size 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 arranged in sequence 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 magnification lens group and the focus lens group are movable along the optical axis direction;

[0007] The first fixed lens group has positive optical power, the zoom lens group has negative optical power, the focus 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 negative optical power, the fourth lens has negative optical power, and the fifth lens has 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 positive refractive power, the seventh lens has negative refractive power, the eighth lens has positive refractive power, the ninth lens has negative refractive power, and the tenth lens has positive refractive 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 zoom 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 aspheric 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, 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, 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, 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, the total optical length of the zoom lens is TTL; 0.016≤HI / TTL≤0.138.

[0035] The zoom lens provided in an embodiment of the present invention adopts a four-element structure and uses 11 lenses. By setting the number of lenses in the four lens groups and further limiting the optical power combination of the four lens groups and the 11 lenses, the zoom lens has a total optical length (TTL) of 60 mm or less. This achieves high-performance imaging in the 436 nm to 656 nm band on a 1 / 2.7″ target surface, and an F / # of 1.8 to 2.8. This results in a compact, large-aperture, infrared confocal zoom lens that is compatible with 1 / 2.7″ chips and offers high image quality.

[0036] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily 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 structural diagram of a zoom lens at the wide-angle end provided by an embodiment of the present invention;

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

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

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

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

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

[0044] Figure 7 This is a field curvature distortion diagram of the zoom lens provided in Example 1 of the present invention at the wide-angle end;

[0045] Figure 8 This is a field curvature distortion diagram of the zoom lens provided in Example 1 of the present invention at the telephoto end;

[0046] Figure 9 This is a ray fan diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end;

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

[0048] Figure 11 A diagram of vertical axial chromatic aberration of the zoom lens provided in Example 1 of the present invention at the wide-angle end;

[0049] Figure 12 A diagram of vertical axial chromatic aberration of the zoom lens provided in Example 1 of the present invention at the telephoto end;

[0050] Figure 13 This is a diagram of field curvature distortion at the wide-angle end of the zoom lens provided in the second embodiment of the present invention;

[0051] Figure 14 This is a diagram of field curvature distortion at the telephoto end of the zoom lens provided in the second embodiment of the present invention;

[0052] Figure 15 This is a ray fan diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end;

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

[0054] Figure 17 A diagram of vertical axial chromatic aberration of the zoom lens provided in Example 2 of the present invention at the wide-angle end;

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

[0056] Figure 19 This is a diagram of field curvature distortion at the wide-angle end of the zoom lens provided in Example 3 of the present invention;

[0057] Figure 20 This is a diagram of field curvature distortion at the telephoto end of the zoom lens provided in the third embodiment of the present invention;

[0058] Figure 21 This is a ray fan diagram of the zoom lens at the wide-angle end provided by the third embodiment of the present invention;

[0059] Figure 22 This is a ray fan diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention;

[0060] Figure 23 A diagram of vertical axial chromatic aberration of the zoom lens provided in Example 3 of the present invention at the wide-angle end;

[0061] Figure 24 This is a diagram of vertical axis chromatic aberration of the zoom lens provided in Example 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 solutions of the present invention, the technical solutions 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 embodiments described 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 making creative efforts should fall within the scope of protection of the present invention.

[0063] It should be noted that the terms "first", "second", etc. in the description 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 numbers 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 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 This is a schematic structural diagram of a zoom lens at the wide-angle end provided by an embodiment of the present invention. Figure 2A schematic structural diagram of a zoom lens at the telephoto end provided by an embodiment of the present invention; Figure 3 This is a schematic structural diagram of another zoom lens at the wide-angle end provided by an embodiment of the present invention. Figure 4 A schematic structural diagram of another zoom lens at the telephoto end provided by an embodiment of the present invention; Figure 5 A schematic structural diagram of another zoom lens at the wide-angle end provided by an embodiment of the present invention is shown. Figure 6 A structural diagram of another zoom lens at the telephoto end provided by an embodiment of the present invention; Figures 1-6 As shown, the zoom lens provided by the embodiment of the present invention includes a first fixed lens group G1, a variable magnification lens group G2, a focus lens group G3 and a second fixed lens group G4 arranged in sequence along the optical axis from the object plane to the image plane.

[0065] The first fixed lens group G1 and the second fixed lens group G4 are fixed, and the zoom lens group G2 and the focus lens group G3 are movable along the optical axis.

[0066] The first fixed lens group G1 has positive refractive power, the zoom lens group G2 has negative refractive power, the focus lens group G3 has positive refractive power, and the second fixed lens group G4 has negative refractive 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 negative refractive power, and the second lens L2 has positive refractive power.

[0068] The variator 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 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] Focusing lens group G3 includes, arranged in order from the object plane to the image plane, sixth lens L6, seventh lens L7, eighth lens L8, ninth lens L9, and tenth lens L10; sixth lens L6 has positive refractive power, seventh lens L7 has negative refractive power, eighth lens L8 has positive refractive power, ninth lens L9 has negative refractive power, and 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, such as Figures 1-6 As shown, the zoom lens provided by the embodiment of the present invention comprises, 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 variator lens group G2 with negative optical focal length, a focus 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 stationary 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. 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 zoom 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 shortest and at the telephoto end when the focal length is 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 beam and the convergence of the object-side beam, and it characterizes the ability of an 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), a single lens, or a system formed by multiple lenses (i.e., a lens group).

[0077] In an embodiment of the present invention, the optical focal length of the first fixed lens group G1 is positive, which can converge the light 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 light contraction in the subsequent structure to adapt to different focal length requirements.

[0078] Furthermore, the first fixed lens group G1, the zoom 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 light can be reasonably converged and diverged when passing through each lens group, ensuring that the light will not be excessively deflected and 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 operate at a larger aperture, which is conducive to increasing the aperture of the lens.

[0079] Continue to refer Figures 1-6 The number of lenses with optical power in the first fixed lens group G1 can be 2, wherein the first fixed lens group G1 can 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 beam of incident light, allowing more light to enter the subsequent lens group, thereby facilitating the realization of a larger aperture.

[0081] The second lens L2 has positive refractive power, that is, a combination of a negative lens and a positive lens, which helps control the light path and makes it pass through the subsequent lens group more smoothly. At the same time, it also helps to offset the dispersion effect 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 variator lens group G2 may be three, wherein the variator 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 an embodiment of the present invention, a four-element structure is adopted, using 11 lenses. By setting the number of lenses in the four lens groups and further limiting the optical power combination of the four lens groups and the 11 lenses, the total optical length (TTL) of the zoom lens satisfies TTL ≤ 60mm, achieving high-performance imaging from 436nm to 656nm at a 1 / 2.7" target surface, and the aperture number F / # can reach 1.8 to 2.8, thereby realizing a high-image-quality zoom lens with a small size, large aperture, infrared confocality, and compatibility with a 1 / 2.7" chip.

[0087] As a feasible implementation method, continue to refer to Figures 1-6 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 sixth lens L6 has a convex object-side surface and a convex image-side surface; the seventh lens L7 has a convex object-side surface; the eighth lens L8 has a convex object-side surface; the ninth lens L9 has a concave object-side surface and a concave image-side surface; and the tenth lens L10 has a convex object-side surface and a convex image-side surface.

[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 rationally matching the surface shapes of the various lenses, while satisfying the optical power requirements of each lens and achieving the desired optical performance indicators (such as small size, large aperture, and 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 Figures 1-6 As a feasible implementation, the zoom lens further includes an aperture STO, which 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 that the distribution of light entering the subsequent lenses is controlled by 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 the image height is increased and the target surface is expanded at the rear end of the zoom lens while maintaining good imaging quality at a large aperture, thereby meeting the usage requirements in more situations.

[0095] Continue to refer Figures 1-6 As a feasible implementation, the zoom lens may further include a flat glass P. The flat glass P 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 this 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 be used to generate digital images or videos through a series of processing steps.

[0098] Continue to refer Figures 1-6 As a feasible implementation, the focal length of the first fixed lens group G1 is FG1, the focal length of the variator 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; and -10.014 ≤ FG4 / FT ≤ -1.081.

[0099] Among them, by further limiting the focal length of each lens group, the optical power of each lens can be reasonably matched, allowing light to pass through the zoom lens more smoothly. At the same time, the high-level aberrations of the zoom lens can be corrected to a greater extent, improving image quality while achieving a larger aperture.

[0100] Continue to refer Figures 1-6 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, such as Figures 1-6As shown, cementing the first lens L1 and the second lens L2 can minimize or eliminate chromatic aberration, fully correcting the chromatic aberration of the zoom lens. It also effectively reduces the air gap between the first lens L1 and the second lens L2, further shortening the overall optical length of the lens.

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

[0103] Similarly, cementing the fourth lens L4 and the fifth lens L5 together, and / or cementing 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 here.

[0104] Continue to refer Figures 1-6 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; and 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 variator lens group G2 is 2.082 to 2.969 times the maximum movable distance D3 of the focus lens group G3. During zooming, the variator lens group G2 has a larger range of movement, allowing for more efficient focal length changes and ensuring rapid response of the zoom lens during zooming. This allows the zoom lens to quickly adjust the focal length during zooming, enabling rapid switching from wide-angle to telephoto. The focus lens group G3 has a relatively smaller range of movement, which can be used for fine-tuning the focus, ensuring rapid response of the zoom lens during focusing, allowing for rapid focus adjustment and achieving fast and precise focusing.

[0107] The maximum movable distance D2 of the variable magnification lens group G2 and the total optical length TTL of the zoom lens satisfy 0.213≤D2 / TTL≤0.534, which ensures that the variable magnification lens group G2 can effectively move during zooming, realizes zooming from wide angle to long shot, and meanwhile, the movement of the variable magnification lens group G2 does not occupy too much total length of the lens, thereby helping to reduce the volume of the lens.

[0108] The maximum movable distance ratio of the variable magnification lens group G2 in the lens and the maximum movable distance ratio of the variable magnification lens group G2 and the focusing lens group G3 are limited, which realizes fast response of the zoom lens to zoom-focusing function, ensures that the zooming and focusing can be quickly adjusted, and meanwhile, the zoom lens is more compact and the total volume of the zoom lens is reduced.

[0109] Optionally, by setting the back focal length BFL and the total optical length TTL of the zoom lens to satisfy 0.073≤BFL / TTL≤0.107, the total length can be reduced as much as possible while maintaining good optical performance, sufficient space can be provided for the rear structure of the lens, and good compatibility of the lens with various sensors and accessories (such as filters, protective glasses, etc.) can be ensured.

[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 aspheric 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 application contains at least four aspheric 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] At least one glass aspheric lens can be arranged in the variable magnification lens group G2, the focusing lens group G3 and the second fixed lens group G4, which can correct the spherical aberration and high-order aberration of the above lens groups, is beneficial to improve the image quality and aperture, and optimizes the volume and weight of the lens.

[0113] In the embodiment of the present application, the fourth lens L4, the fifth lens L5, the tenth lens L10 and the eleventh lens L11 are aspheric lenses, which can make the light pass through the entire lens system more smoothly, without too large deflection, and at the same time, can ensure that the light has a larger aperture before entering the diaphragm, so that the light can pass through smoothly even if the diaphragm opening is large, without aberration caused by sudden contraction, thereby allowing the lens to work at a larger aperture, which is beneficial to increase the aperture of the lens.

[0114] Furthermore, the use of aspheric lenses in the fourth lens element L4, the fifth lens element L5, the tenth lens element L10, and the eleventh lens element L11 ensures a more uniform distribution of aspheric lenses within the zoom lens, effectively correcting aberrations throughout the entire zoom range and ensuring excellent image quality at all focal lengths. Furthermore, the even distribution of aspheric lenses better coordinates the optical performance of the entire lens system, reducing local aberration accumulation and improving overall image 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 reduce costs and facilitates manufacturing.

[0116] In this embodiment, the aspheric lens is a plastic lens, which can reduce lens cost and weight. The spherical lens is a glass lens, which can achieve higher transmittance and reduce light energy loss, which is conducive to better imaging in low-light environments. Glass lenses also have the advantages of high hardness, strong wear resistance, long service life, and are not easily deformed by temperature, which can further stabilize the performance of the zoom lens.

[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 is made of 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 located near the aperture, and the intersection points of the field rays at different apertures of the lens are close. Therefore, this position is extremely beneficial for correcting 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 Figures 1-6 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, and aberrations and distortion can be reduced. 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 the usage requirements of more chips.

[0126] As a feasible implementation manner, the focal length of the zoom lens at the wide-angle end is FW, 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 lens's zoom range and focal length range can be controlled, so that the lens can meet 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 diagonal length of the image plane or the diameter of the image plane.

[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] The following further describes specific embodiments of the zoom lens applicable to the above-described embodiments with reference to the accompanying drawings.

[0132] Embodiment One

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

[0134] The first fixed lens group G1 comprises a first lens L1 and a second lens L2 arranged in sequence from the object plane to the image plane. The variable magnification lens group G2 comprises 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 focusing lens group G3 comprises 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 comprises an eleventh lens L11.

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

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

[0137] Table 1 details the specific optical and physical parameters of each lens in the zoom lens provided by the embodiment one of the present application in a feasible embodiment. The zoom lens in Table 1 corresponds to Figure 1 and Figure 2 the zoom lens shown in

[0138] Table 1: Design values of optical and physical parameters of the zoom lens

[0139] Surface number Surface type Radius of curvature thickness Materials (nd) 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 surface of the first lens, "2" represents the image side surface 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 curved toward the image side, and a negative value represents that the surface is curved toward the object side, where "INF" indicates that the surface is flat and the radius of curvature is infinite; thickness represents the central axial distance from the current surface to the next surface; 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; material (vd) is the Abbe number, which represents the dispersion characteristics of the material 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 the 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 end 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 sagittal 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 reciprocal of the curvature radius; k is the fitting 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] For example, Table 3 describes in detail the aspheric conic 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-fit 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 end 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 Example 1 of the present invention at the wide-angle end. Figure 8 This is a diagram showing the field curvature distortion of the zoom lens provided in Example 1 of the present invention at the telephoto end. In the left-hand coordinate system, the horizontal coordinate represents the field curvature in millimeters, while the vertical coordinate represents the normalized image height (unitless), where T represents the meridian and S represents the arc loss. In the right-hand coordinate system, the horizontal coordinate represents the distortion (F-Tan(Theta)) in percentages, while the vertical coordinate represents the normalized image height (unitless). 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 both the wide-angle end and the telephoto end. That is, when imaging, the difference in image quality between the center and the periphery is relatively small. At the same time, the distortion of the zoom lens at both the wide-angle end and the telephoto end is also well corrected.

[0156] Figure 9 This is a ray fan diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end. Figure 10 The ray fan diagram of the zoom lens at the telephoto end provided in the first 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 diffusion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 9 and Figure 10 It can be seen that the zoom lens is well aligned with the horizontal axis at all wavelengths in all fields of view, indicating that the vertical aberration of each wavelength is well corrected. At the same time, there is no obvious dispersion in the curves of each wavelength, indicating that the chromatic aberration of the zoom lens at the wide-angle and telephoto ends is also well corrected, thus meeting the requirements of high-resolution imaging.

[0157] Figure 11 This is a diagram of vertical axial chromatic aberration of the zoom lens provided in Example 1 of the present invention at the wide-angle end. Figure 12 This is a diagram of vertical axial chromatic aberration of the zoom lens provided in Example 1 of the present invention at the telephoto end. The vertical direction represents the normalized field of view, with 0 indicating the optical axis. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength in micrometers (μm). Figure 11 and Figure 12 The maximum field of view is 3.45 mm. Figure 11 and Figure 12 It can be seen that the vertical chromatic aberration of different wavelengths is well controlled, indicating that the vertical chromatic aberration of this zoom lens at both the wide-angle and telephoto ends is well controlled, which can meet the needs of wide-spectrum applications.

[0158] Example 2

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

[0160] The first fixed lens group G1 includes the first lens L1 and the second lens L2, arranged in order from the object plane to the image plane. The zoom lens group G2 includes the third lens L3, the fourth lens L4, and the fifth lens L5, arranged in order from the object plane to the image plane. The focusing lens group G3 includes the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, and the tenth lens L10, arranged in order from the object plane to the image plane. The second fixed lens group G4 includes the 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 details 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 (nd) 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 surface of the first lens, "2" represents the image side surface 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 curved toward the image side, and a negative value represents that the surface is curved toward the object side, where "INF" indicates that the surface is flat and the radius of curvature is infinite; thickness represents the central axial distance from the current surface to the next surface; 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; material (vd) is the Abbe number, which represents the dispersion characteristics of the material 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.

[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 end 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 sagittal 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 reciprocal of the curvature radius; k is the fitting 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] For example, Table 7 describes in detail the aspheric conic coefficients 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-fit 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 end 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] Figure 13 This is a diagram of field curvature distortion of the zoom lens provided in Example 2 of the present invention at the wide-angle end. Figure 14 This is a diagram of the field curvature distortion at the telephoto end of the zoom lens provided in Example 2 of the present invention. In the left-hand coordinate system, the horizontal coordinate represents the field curvature in millimeters, while the vertical coordinate represents the normalized image height (unitless), where T represents the meridian and S represents the arc loss. In the right-hand coordinate system, the horizontal coordinate represents the distortion (F-Tan(Theta)) in percent, while the vertical coordinate represents the normalized image height (unitless). Figure 13 The maximum field of view is 43.345 degrees. Figure 14 The maximum field of view is 8.738 degrees. Figure 13 and Figure 14 It can be seen that the field curvature of the zoom lens provided in this embodiment is effectively controlled at both the wide-angle end and the telephoto end. That is, when imaging, the difference in image quality between the center and the periphery is relatively small. At the same time, the distortion of the zoom lens at both the wide-angle end and the telephoto end is also well corrected.

[0182] Figure 15 This is a ray fan diagram of the zoom lens at the wide-angle end provided by the second embodiment of the present invention. Figure 16 The ray 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 diffusion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 15 and Figure 16 It can be seen that the zoom lens is well aligned with the horizontal axis at all wavelengths in all fields of view, indicating that the vertical aberration of each wavelength is well corrected. At the same time, there is no obvious dispersion in the curves of each wavelength, indicating that the chromatic aberration of the zoom lens at the wide-angle and telephoto ends is also well corrected, thus meeting the requirements of high-resolution imaging.

[0183] Figure 17 This is a diagram of vertical axis chromatic aberration of the zoom lens provided in Example 2 of the present invention at the wide-angle end. Figure 18 This is a diagram of vertical axial chromatic aberration of the zoom lens provided in Example 2 of the present invention at the telephoto end. The vertical direction represents the normalized field of view, with 0 indicating the optical axis. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength in micrometers (μm). Figure 17 and Figure 18 The maximum field of view is 3.5 mm. Figure 17 and Figure 18 It can be seen that the axial chromatic aberration of different wavelengths is controlled in a good range, which shows that the axial chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is well controlled, and the wide-spectrum application requirement can be met.

[0184] Embodiment Three

[0185] As shown in Figure 5 and Figure 6 , the zoom lens provided by the embodiment three of the present application comprises, in sequence along the optical axis from the object plane to the image plane, a first fixed lens group G1, a variable magnification lens group G2, a focusing lens group G3 and a second fixed lens group G4.

[0186] The first fixed lens group G1 comprises, in sequence from the object plane to the image plane, a first lens L1 and a second lens L2. The variable magnification lens group G2 comprises, in sequence from the object plane to the image plane, a third lens L3, a fourth lens L4 and a fifth lens L5. The focusing lens group G3 comprises, in sequence from the object plane to the image plane, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a tenth lens L10. The second fixed lens group G4 comprises 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; and the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a third cemented lens group g3.

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

[0189] Table 9 details the specific optical and physical parameters of each lens in the zoom lens provided by the embodiment three of the present application in a feasible implementation manner. The zoom lens in Table 9 corresponds to Figure 5 and Figure 6 the zoom lens shown in

[0190] Table 9: Design values of optical and physical parameters of the zoom lens

[0191] Surface number Surface type Radius of curvature thickness Materials (nd) 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 surface of the first lens, "2" represents the image side surface 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 curved toward the image side, and a negative value represents that the surface is curved toward the object side, where "INF" indicates that the surface is flat and the radius of curvature is infinite; thickness represents the central axial distance from the current surface to the next surface; 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; material (vd) is the Abbe number, which represents the dispersion characteristics of the material 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.

[0193] Table 10 shows the values ​​of the zoom intervals of the zoom lenses 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 end 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 sagittal 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 reciprocal of the curvature radius; k is the fitting 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] For example, Table 11 describes in detail the aspheric conic coefficients of each lens in Example 3 in a feasible implementation manner.

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

[0201]

[0202]

[0203] The K value in Table 11 represents the numerical value of the best-fit 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 end 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] Figure 19 This is a field curvature distortion diagram of the zoom lens provided in Example 3 of the present invention at the wide-angle end. Figure 20 This is a diagram of the field curvature distortion at the telephoto end of the zoom lens provided in Example 3 of the present invention. In the left-hand coordinate system, the horizontal coordinate represents the field curvature in millimeters, while the vertical coordinate represents the normalized image height (unitless), where T represents the meridian and S represents the arc loss. In the right-hand coordinate system, the horizontal coordinate represents the distortion (F-Tan(Theta)) in percent, while the vertical coordinate represents the normalized image height (unitless). Figure 19 The maximum field of view is 38.486 degrees. Figure 20 The maximum field of view is 9.229 degrees. Figure 19 and Figure 20 It can be seen that the field curvature of the zoom lens provided in this embodiment is effectively controlled at both the wide-angle end and the telephoto end. That is, when imaging, the difference in image quality between the center and the periphery is relatively small. At the same time, the distortion of the zoom lens at both the wide-angle end and the telephoto end is also well corrected.

[0208] Figure 21 This is a ray fan diagram of the zoom lens provided in the third embodiment of the present invention at the wide-angle end. Figure 22 The ray fan diagram of the zoom lens at the telephoto end provided in the third embodiment of the present invention. The horizontal axis in the diagram 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 diffusion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 21 and Figure 22 It can be seen that the zoom lens is well aligned with the horizontal axis at all wavelengths in all fields of view, indicating that the vertical aberration of each wavelength is well corrected. At the same time, there is no obvious dispersion in the curves of each wavelength, indicating that the chromatic aberration of the zoom lens at the wide-angle and telephoto ends is also well corrected, thus meeting the requirements of high-resolution imaging.

[0209] Figure 23 This is a diagram of vertical axial chromatic aberration of the zoom lens provided in Example 3 of the present invention at the wide-angle end. Figure 24 This is a diagram of vertical axial chromatic aberration of the zoom lens provided in Example 3 of the present invention at the telephoto end. The vertical direction represents the normalized field of view, with 0 indicating the optical axis. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength in micrometers (μm). Figure 23 and Figure 24 The maximum field of view is 3.45 mm. Figure 23and Figure 24 It can be seen that the vertical chromatic aberration of different wavelengths is well controlled, indicating that the vertical chromatic aberration of this zoom lens at both the wide-angle and telephoto ends is well controlled, which can meet the needs of wide-spectrum applications.

[0210] In order to more clearly illustrate the above embodiments, 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] Example 1 Example 2 Example 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 embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A zoom lens, characterized in that: The lens system comprises a first fixed lens group, a zoom lens group, a focus lens group, and a second fixed lens group, which are arranged in sequence along the optical axis from the object plane to the image plane. The total number of lens groups is four. The first fixed lens group and the second fixed lens group are fixedly arranged, and the variable magnification lens group and the focus lens group are movable along the optical axis direction; The first fixed lens group has positive optical power, the zoom lens group has negative optical power, the focus 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 negative optical power, the fourth lens has negative optical power, and the fifth lens has 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 positive refractive power, the seventh lens has negative refractive power, the eighth lens has positive refractive power, the ninth lens has negative refractive power, and the tenth lens has positive refractive power; The second fixed lens group includes an eleventh lens; the eleventh lens has negative optical power; The focal length of the first fixed lens group is FG1, the focal length of the zoom 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.

2. 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.

3. 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.

4. 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.

5. 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.

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

341.

7. 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.

8. 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.

9. 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