Zoom lens and lens module

Abstract

The invention discloses a zoom lens and a lens module. The zoom lens comprises a first fixed lens group, a zoom lens group, a focusing lens group and a second fixed lens group; the first lens has negative focal power, the second lens has positive focal power, the third lens has negative focal power, the fourth lens has negative focal power, the fifth lens has positive focal power, the sixth lens has positive focal power, the seventh lens has negative focal power, the eighth lens has positive focal power, and the ninth lens has negative focal power. The tenth lens has positive focal power, and the eleventh lens has positive focal power, so that the zoom lens can ensure that the zoom lens is confocal in a full wave band, is smaller in size, larger in aperture and higher in image quality, and meets wider use requirements.

Description

Technical Field

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

[0002] In the security field, zoom lenses have been widely used due to their advantages such as long shooting distance and large shooting angle; 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 using chips with 1 / 4' target surfaces are widely used in places where standard-sized zoom lenses or pan-tilt cameras cannot be accommodated due to their advantages such as smallest size, lightest weight, and high cost-effectiveness. Currently, 1 / 4' zoom lenses on the market generally have defects such as low zoom ratio, small F number, and cannot be used at night. Summary of the Invention

[0004] The present invention provides a zoom lens and a lens module to solve the problem of a zoom lens with large magnification, large aperture and infrared confocality.

[0005] In a first aspect, the present invention provides a zoom lens comprising a first fixed lens group, a zoom lens group, a focus lens group, and a second fixed lens group 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 fixed, and the zoom lens group and the focus lens group are movable along the optical axis;

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

[0008] The first fixed lens group includes a first lens and a second lens arranged in sequence along the optical axis 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 along the optical axis from the object plane to the image plane, the third lens having negative optical power, the fourth lens having negative optical power, and the fifth lens having 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 along the optical axis from the object plane to the image plane, the sixth lens having positive focal power, the seventh lens having negative focal power, the eighth lens having positive focal power, the ninth lens having negative focal power, and the tenth lens having positive focal power;

[0011] The second fixed lens group includes an eleventh lens having positive refractive power.

[0012] Optionally, the focal length of the first fixed lens group is F1, the focal length of the zoom lens group is F2, the focal length of the focus lens group is F3, the focal length of the second fixed lens group is F4, and the focal length of the zoom lens at the wide-angle end is FW; wherein,

[0013] 12.00≤F1 / FW≤18.50;

[0014] -23.50≤F2 / FW≤-19.00;

[0015] -17.50≤F3 / FW≤-7.00;

[0016] 2.00≤F4 / FW≤24.00.

[0017] Optionally, the maximum movable distance of the zoom lens group is S2, and the maximum movable distance of the focus lens group is S3; wherein, 0.85≤S2 / S3≤0.90.

[0018] Optionally, the fourth lens and the fifth lens form a first cemented lens group; the seventh lens, the eighth lens and the ninth lens form a second cemented lens group;

[0019] The focal length of the first cemented lens group in the zoom lens group is F45, the focal length of the second cemented lens group in the focus lens group is F789, and the focal length of the zoom lens at the wide-angle end is FW; wherein,

[0020] -20.50≤F45 / FW≤-19.00;

[0021] -17.50≤F789 / FW≤-7.00.

[0022] Optionally, the refractive index of the first lens is Nd1, and the Abbe number is Vd1; the refractive index of the fourth lens is Nd4, and the Abbe number is Vd4; the refractive index of the fifth lens is Nd5, and the Abbe number is Vd5; the refractive index of the eighth lens is Nd8, and the Abbe number is Vd8; the refractive index of the eleventh lens is Nd11, and the Abbe number is Vd11, wherein:

[0023] 1.98≤Nd1≤2.06;16.00≤Vd1≤27.50;

[0024] 1.54≤Nd4≤1.56;53.50≤Vd4≤56.00;

[0025] 1.70≤Nd5≤1.72, 19.00≤Vd5≤51.00;

[0026] 1.43≤Nd8≤1.51;80.00≤Vd8≤96.00;

[0027] 1.54≤Nd11≤1.56;53.50≤Vd11≤56.00.

[0028] Optionally, the focal length of the zoom lens at the wide-angle end is FW, and the entrance pupil diameter of the zoom lens at the wide-angle end is EPDW; wherein,

[0029] 1.43≤FW / EPDW≤1.50.

[0030] Optionally, the maximum lens diameter in the first fixed lens group is ΦG1, and the total optical length of the zoom lens at the wide-angle end is TTL; wherein,

[0031] 10.62≤ΦG1 / TTL≤12.60.

[0032] Optionally, at least one plastic aspheric lens is provided in the zoom lens group and the focus lens group;

[0033] The eleventh lens is a plastic aspherical lens.

[0034] Optionally, the zoom lens further includes a diaphragm, and the diaphragm is located between the zoom lens group and the focus lens group.

[0035] In a second aspect, the present invention provides a lens module, comprising a photosensitive chip and the zoom lens according to any one of the first aspects, wherein the photosensitive chip is disposed on the image plane side of the zoom lens;

[0036] The diagonal length of the photosensitive chip is H, the tangent value of the incident angle of the zoom lens at the wide-angle end is TAN(θW), and the tangent value of the incident angle of the zoom lens at the telephoto end is TAN(θT); wherein,

[0037] 2.95≤H / TAN(θW)≤3.50;

[0038] 18.00≤H / TAN(θT)≤22.00.

[0039] The technical solution of the embodiments of the present invention is to provide a zoom lens with a four-element structure and 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, a zoom lens with full focal length confocality in the 436nm-850nm band on a 1 / 4" target surface is achieved, while also having a smaller size, a larger aperture, and higher image quality.

[0040] 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

[0041] 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.

[0042] Figure 1 A schematic structural diagram of a zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0043] Figure 2 A schematic structural diagram of a zoom lens at the telephoto end provided by an embodiment of the present invention;

[0044] Figure 3 This is an axial aberration diagram of the zoom lens provided in Example 1 of the present invention at the wide-angle end;

[0045] Figure 4 This is a ray fan diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end;

[0046] Figure 5 The vertical axis chromatic aberration curve of the zoom lens provided in the first embodiment of the present invention at the wide-angle end;

[0047] Figure 6 This is a diagram of the axial aberration of the zoom lens provided in the first embodiment of the present invention at the telephoto end;

[0048] Figure 7 A ray fan diagram of the zoom lens at the telephoto end provided by the first embodiment of the present invention;

[0049] Figure 8 The vertical axis chromatic aberration curve of the zoom lens provided in the first embodiment of the present invention at the telephoto end;

[0050] Figure 9 A schematic structural diagram of a zoom lens at the wide-angle end provided in the second embodiment of the present invention;

[0051] Figure 10 A schematic structural diagram of a zoom lens at the telephoto end provided by the second embodiment of the present invention;

[0052] Figure 11 This is an axial aberration diagram of the zoom lens provided in Example 2 of the present invention at the wide-angle end;

[0053] Figure 12 This is a ray fan diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end;

[0054] Figure 13 Vertical axis chromatic aberration curve of the zoom lens provided in Example 2 of the present invention at the wide-angle end

[0055] Figure 14 This is a diagram of the axial aberration of the zoom lens provided in the second embodiment of the present invention at the telephoto end;

[0056] Figure 15 A ray fan diagram of the zoom lens at the telephoto end provided by the second embodiment of the present invention;

[0057] Figure 16 The vertical axis chromatic aberration curve of the zoom lens provided in the second embodiment of the present invention at the telephoto end;

[0058] Figure 17 This is a schematic structural diagram of a zoom lens at the wide-angle end provided by Embodiment 3 of the present invention;

[0059] Figure 18 A schematic structural diagram of a zoom lens at the telephoto end provided by the third embodiment of the present invention;

[0060] Figure 19 This is an axial aberration diagram of the zoom lens provided in Example 3 of the present invention at the wide-angle end;

[0061] Figure 20 This is a ray fan diagram of the zoom lens provided in the third embodiment of the present invention at the wide-angle end;

[0062] Figure 21 This is a vertical chromatic aberration curve of the zoom lens provided in the third embodiment of the present invention at the wide-angle end;

[0063] Figure 22 This is a diagram of the axial aberration of the zoom lens provided in the third embodiment of the present invention at the telephoto end;

[0064] Figure 23 This is a ray fan diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention;

[0065] Figure 24 This is the vertical axis chromatic aberration curve of the zoom lens provided in the third embodiment of the present invention at the telephoto end. DETAILED DESCRIPTION

[0066] 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.

[0067] 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.

[0068] 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 2 A schematic diagram of the structure of a zoom lens at the telephoto end provided by an embodiment of the present invention is shown in FIG. Figure 1 and Figure 2As shown, the zoom lens includes a first fixed lens group G1, a zoom lens group G2, a focus lens group G3 and a second fixed lens group G4 which are arranged in sequence along the optical axis from the object plane to the image plane; the first fixed lens group G1 and the second fixed lens group G4 are fixedly arranged, and the zoom lens group G2 and the focus lens group G3 are movable along the optical axis; the first fixed lens group G1 has positive focal power, the zoom lens group G2 has negative focal power, the focus lens group G3 has negative focal power, and the second fixed lens group G4 has positive focal power; the first fixed lens group G1 includes a first lens 101 and a second lens 102 which are arranged in sequence along the optical axis from the object plane to the image plane, the first lens 101 has negative focal power, and the second lens 102 has positive focal power; the zoom lens group G2 includes a first lens 101 and a second lens 102 which are arranged in sequence along the optical axis from the object plane to the image plane, the first lens 101 has negative focal power, and the second lens 102 has positive focal power. A third lens 103, a fourth lens 104 and a fifth lens 105 are arranged in sequence along the optical axis from the object plane to the image plane, the third lens 103 has negative focal power, the fourth lens 104 has negative focal power, and the fifth lens 105 has positive focal power; the focusing lens group G3 includes a sixth lens 106, a seventh lens 107, an eighth lens 108, a ninth lens 109 and a tenth lens 110, which are arranged in sequence along the optical axis from the object plane to the image plane, the sixth lens 106 has positive focal power, the seventh lens 107 has negative focal power, the eighth lens 108 has positive focal power, the ninth lens 109 has negative focal power, and the tenth lens 110 has positive focal power; the second fixed lens group G4 includes an eleventh lens 111, and the eleventh lens 111 has positive focal power.

[0069] For example, in the zoom lens provided in this embodiment, the first fixed lens group G1, the zoom lens group G2, the focus lens group G3 and the second fixed lens group G4 can be arranged in one lens barrel ( Figure 1 The first fixed lens group G1 and the second fixed lens group G4 are fixed in position within the lens barrel, while the zoom lens group G2 and the focus lens group G3 can reciprocate along the optical axis within the lens barrel. Through the combined movement of the zoom lens group G2 and the focus lens group G3, the focal length of the zoom lens can be continuously changed from wide-angle to telephoto, ensuring high image quality at all focal positions while also ensuring the miniaturization of the zoom lens.

[0070] It can be understood that in the process of zooming by moving the zoom lens group G2 and the focus lens group G3, the zoom lens is located at the wide-angle end when the focal length is shortest, and is located 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, and also has different lengths or shapes.

[0071] Furthermore, the optical power 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 optical power, the stronger the ability to bend light, and the smaller the absolute value of the optical power, the weaker the ability to bend light. When the optical power is a positive number, the refraction of light is convergent; when the optical power is a negative number, the refraction of light is divergent. The optical power can be used to characterize a certain refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a certain lens, and can also be used to characterize a system formed by multiple lenses (i.e., a lens group).

[0072] In this embodiment, the first fixed lens group G1 is set to have a positive optical focal length, the zoom lens group G2 is set to have a negative optical focal length, the focus lens group G3 is set to have a negative optical focal length, and the second fixed lens group G4 is set to have a positive optical focal length; the optical focal lengths of the first fixed lens group G1, the zoom lens group G2, the focus lens group G3 and the second fixed lens group G4 cooperate with each other, and can compensate for the aberrations caused by the zoom movement of the zoom lens group G2 and the focus lens group G3, thereby ensuring the clarity of the image under different focal length states.

[0073] Further, such as Figure 1 and Figure 2 As shown, the first fixed lens group G1 includes a first lens 101 with negative optical power and a second lens 102 with positive optical power, which are arranged in sequence along the optical axis from the object plane to the image plane; the first lens 101 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. The second lens 102 has a positive optical power, that is, the combination of a negative lens and a positive lens is beneficial for controlling the light path, allowing it to pass 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. 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. At the same time, it can also reduce the number of air-glass interfaces that the light passes through, thereby reducing reflection losses and improving overall light transmittance. The zoom lens group G2 includes a third lens 103 with negative optical power, a fourth lens 104 with negative optical power and a fifth lens 105 with positive optical power; the focusing lens group G3 includes a sixth lens 106 with positive optical power, a seventh lens 107 with negative optical power, an eighth lens 108 with positive optical power, a ninth lens 109 with negative optical power and a tenth lens 110 with positive optical power, and the second fixed lens group G4 includes an eleventh lens 111 with positive optical power.

[0074] The zoom lens provided by the present invention utilizes only 11 lenses, a relatively small number of which helps reduce the lens length to less than 53mm. By properly combining the focal lengths of these 11 lenses, aberrations can be effectively corrected, resulting in an ultra-wide-angle, large aperture (F1.49 to F3.01) and infrared confocal zoom lens with full focal length. This lens is compatible with sensors as large as 1 / 1.4" (1 / 1.4"), thus meeting a wide range of security surveillance needs.

[0075] In summary, the embodiments of the present invention provide a four-element zoom lens, comprising a first fixed lens group G1, a zoom 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. Specifically, 11 lenses are used, resulting in a relatively small number of lenses, thereby helping to reduce the length of the lens. By properly matching the first fixed lens group G1, the zoom lens group G2, the focus lens group G3, and the second fixed lens group G4, as well as the optical power of each lens therein, aberrations can be effectively corrected, ensuring image clarity at different focal lengths. At the same time, the zoom lens has the advantages of a small size, a large aperture, and a large aperture, meeting a wider range of usage requirements.

[0076] As an implementable method, continue to refer to Figure 1 and Figure 2 In the first fixed lens group G1, the object-side surface of the first lens 101 is convex, and the image-side surface is concave; the object-side surface of the second lens 102 is convex. In the zoom lens group, the image-side surface of the third lens 103 is concave; the object-side surface and the image-side surface of the fourth lens 104 are concave; and the object-side surface and the image-side surface of the fifth lens 105 are convex.

[0077] In the focusing lens group G3, the object-side surface of the sixth lens 106 is convex, and the image-side surface is concave; the object-side surface of the seventh lens 107 is convex, and the image-side surface is concave; the object-side surface of the eighth lens 108 is convex, and the image-side surface is convex; the object-side surface of the ninth lens 109 is concave, and the image-side surface is concave; and the object-side surface of the tenth lens 110 is convex, and the image-side surface is convex. In the second fixed lens group G4, the object-side surface of the eleventh lens 111 is concave, and the image-side surface is convex. The surface shape of a lens affects the direction of light propagation and determines how light bends when passing through the lens, which in turn affects the maximum aperture and light throughput of the lens, as well as the quality and characteristics of the imaging.

[0078] In this embodiment, the imaging effect of the zoom lens can be further adjusted through the surface design of each lens and the optical power of each lens.

[0079] As an implementation method, the focal length of the first fixed lens group G1 is F1, the focal length of the zoom lens group G2 is F2, the focal length of the focus lens group G3 is F3, and the focal length of the second fixed lens group G4 is F4. The focal length of the zoom lens at the wide-angle end is FW. Among them, 12.00 ≤ F1 / FW ≤ 18.50; -23.50 ≤ F2 / FW ≤ -19.00; -17.50 ≤ F3 / FW ≤ -7.00; and 2.00 ≤ F4 / FW ≤ 24.00. This lens combination achieves a reasonable combination of optical power, allowing light to pass through the lens more smoothly, and largely correcting the impact of higher-order lens aberrations on image quality.

[0080] As one possible implementation, the maximum movable distance of the zoom lens group G2 is S2, and the maximum movable distance of the focus lens group G3 is S3; where 0.85 ≤ S2 / S3 ≤ 0.90. By controlling the travel ratio of the zoom lens group G2 and the focus lens group G3 during movement, efficient utilization of the movable areas of the zoom lens group G2 and the focus lens group G3 is achieved, minimizing the lens size to the greatest extent possible.

[0081] In one embodiment, at least one plastic aspheric lens is included in the zoom lens group G2 and the focus lens group G3; the eleventh lens 111 is also a plastic aspheric lens. The fourth and fifth lenses 104 and 105 in the zoom lens group G2 are both plastic aspheric lenses, and the third lens 103 is a glass spherical lens. The tenth lens 110 in the focus lens group G3 is also a plastic aspheric lens, and the sixth, seventh, eighth, and ninth lenses 106 and 107 are all glass spherical lenses. The first and second lenses 101 and 102 in the first fixed lens group G1 are both glass spherical lenses; and the eleventh lens 111 in the second fixed lens group G4 is also a glass spherical lens. The cost of plastic lenses is much lower than that of glass lenses, which can reduce the cost of the zoom lens. Furthermore, the two materials, glass and plastic, can complement each other, balancing high and low temperatures and reducing the overall lens length. This ensures that the zoom lens has stable high and low temperature performance, improving its environmental adaptability.

[0082] In one embodiment, the fourth lens 104 and the fifth lens 105 form a first cemented lens group; and / or the seventh lens 107, the eighth lens 108, and the ninth lens 109 form a second cemented lens group; the focal length of the first cemented lens group in the zoom lens group G2 is F45, the focal length of the second cemented lens group in the focus lens group G3 is F789, and the focal length of the zoom lens at the wide-angle end is FW; wherein, -20.50≤F45 / FW≤-19.00; and -17.50≤F789 / FW≤-7.00. By forming the first cemented lens group with the fourth lens 104 and the fifth lens 105, and forming the second cemented lens group with the seventh lens 107, the eighth lens 108, and the ninth lens 109, the air gap between the fourth lens 104 and the fifth lens 105, and the air gaps between the seventh lens 107, the eighth lens 108, and the ninth lens 109 can be effectively reduced, thereby further reducing the overall length of the lens. The use of cemented lenses effectively corrects lens aberrations. Using cemented lenses in zoom lens group G2 and focus lens group G3 ensures balanced aberrations during zooming, improving image quality. Furthermore, the plastic cemented lens group simultaneously expands the lens's degrees of freedom, enabling the cementation of the two aspheric surfaces of fourth lens element 104 and fifth lens element 105, further controlling high-order aberrations. The energy absorption of the cemented layer also provides improved impact resistance, meeting the demands of use in complex environments. Compared to the doublet composed of fourth lens element 104 and fifth lens element 105, the triplet composed of seventh lens element 107, eighth lens element 108, and ninth lens element 109 offers superior correction for high-order aberrations, improving image quality.

[0083] As one possible embodiment, the zoom lens further includes an aperture STO, which is located between the zoom lens group G2 and the focus lens group G3. The addition of the aperture STO can adjust the propagation direction of the light beam, thereby improving imaging quality. The aperture STO can be located in the optical path between the fifth lens 105 and the sixth lens 106, but the specific location of the aperture STO is not limited in this embodiment of the present invention.

[0084] As an embodiment, the refractive index of the first lens 101 is Nd1 and the Abbe number is Vd1; the refractive index of the fourth lens 104 is Nd4 and the Abbe number is Vd4; the refractive index of the fifth lens 105 is Nd5 and the Abbe number is Vd5; the refractive index of the eighth lens 108 is Nd8 and the Abbe number is Vd8; the refractive index of the eleventh lens 111 is Nd11 and the Abbe number is Vd11, wherein: 1.98≤Nd1 ≤2.06; 16.00≤Vd1≤27.50; 1.54≤Nd4≤1.56; 53.50≤Vd4≤56.00; 1.70≤Nd5≤1.72, 19.00≤Vd5≤51.00; 1.43≤Nd8≤1.51; 80.00≤Vd8≤96.00; 1.54≤Nd11≤1.56; 53.50≤Vd11≤56.00.

[0085] The refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium. It primarily describes a material's ability to refract light, and different materials have different refractive indices. The Abbe number is an index used to indicate the dispersion capacity of a transparent medium. The greater the dispersion, the smaller the Abbe number; conversely, the less dispersion, the larger the Abbe number. Therefore, by matching the refractive index and Abbe number of each lens in a zoom lens, it is possible to achieve a compact zoom lens design while also facilitating higher pixel resolution and a wider aperture.

[0086] In a zoom lens, using a high-refractive-index material for the first lens element 101 can effectively control the light at the wide-angle edge, avoiding severe coma and distortion. Furthermore, the curvature of the first lens element 101 can be controlled to reduce Fresnel reflection, improve the relative illumination of the lens, and avoid issues such as vignetting. Furthermore, using a high-refractive-index material for the first lens element 101 can effectively reduce the size of the lens group, achieving miniaturization of the lens group.

[0087] In a zoom lens, the zoom lens group G2 before the aperture STO plays a dominant role in adjusting the lens magnification. Using the aforementioned refractive index materials in combination with the lens's focal power can not only correct aberrations but also control the lens's high and low temperature conditions. Simultaneously using the aforementioned materials to form a cemented lens group for the fourth and fifth lenses 104 and 105 not only ensures balanced aberrations but also offers advantages in group volume and size. Furthermore, it can increase the lens's F-number and improve the lens's imaging illumination. The eighth lens 108 is the middle lens in the triplet. This lens, made of a high Abbe number material, acts as a "dispersion buffer layer" for the cemented lens, interrupting the continuous stacking effect of the high-dispersion materials on both sides and forming a dispersion-anti-dispersion-dispersion compensation chain to ensure lens imaging quality. Using the aforementioned refractive index materials in combination with the lens shape for the eleventh lens 111 in the second fixed lens group G4 can better control the exit angle of the zoom lens' light, thereby controlling the lens's imaging quality and target surface size.

[0088] As an implementation method, the focal length of the zoom lens at the wide-angle end is FW, and the entrance pupil diameter of the zoom lens at the wide-angle end is EPDW; wherein 1.43≤FW / EPDW≤1.50.

[0089] As an implementation method, the maximum lens diameter in the first fixed lens group G1 is ΦG1, and the total optical length of the zoom lens at the wide-angle end is TTL; wherein 10.62≤ΦG1 / TTL≤12.60.

[0090] The entrance pupil diameter EPDW of the zoom lens at the wide-angle end can be understood as the diameter of the image formed by the iris STO relative to the front lens group of the zoom lens at the wide-angle end. The iris STO of the zoom lens is fixed between the zoom lens group G2 and the focus lens group G3, which can symmetrize the aberration distribution, correct the field curvature while controlling the lens distortion, and also has a certain inhibitory effect on the lens coma; in addition, the fixed position iris STO can ensure that the incident angle of the light remains relatively stable during the zooming process, avoids sudden changes in the aberration type (such as coma at the wide-angle end becomes spherical aberration at the telephoto end), and has better control over the imaging quality. By controlling the ratio of the focal length of the zoom lens at the wide-angle end to the diameter of the image formed by the iris STO relative to the front lens group, and coordinating the ratio of the maximum lens diameter in the first fixed lens group G1 of the zoom lens to the total optical length at the wide-angle end, the amount of light entering the zoom lens can be guaranteed, and the technical purpose of a large aperture can be achieved.

[0091] As an embodiment, the zoom lens further includes a flat glass plate CG, which is located between the image-side surface and the image plane of the eleventh lens element 111. The flat glass plate CG protects the photosensitive chip in the imaging sensor, which is used to convert the optical signals collected by the zoom lens into electrical signals, thereby ensuring the imaging effect of the zoom lens.

[0092] An embodiment of the present invention further provides a lens module, the lens module comprising a photosensitive chip and the zoom lens according to any one of the above embodiments, wherein the photosensitive chip is arranged on the image plane side of the zoom lens;

[0093] The diagonal length of the photosensitive chip is H, the tangent value of the incident angle of the zoom lens at the wide-angle end is TAN(θW), and the tangent value of the incident angle of the zoom lens at the telephoto end is TAN(θT); wherein, 2.95≤H / TAN(θW)≤3.50; 18.00≤H / TAN(θT)≤22.00. By controlling the diagonal length of the photosensitive chip used in the zoom lens and the tangent value of its incident angle at the wide-angle end / telephoto end, the focal length of the zoom lens can be effectively controlled to meet usage requirements.

[0094] Specific embodiments of the zoom lens applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0095] Example 1

[0096] Continue to refer Figure 1 and Figure 2The zoom lens comprises a first fixed lens group G1, a zoom lens group G2, a focus lens group G3 and a second fixed lens group G4, which are arranged in sequence along the optical axis from the object plane to the image plane; the first fixed lens group G1 has positive focal power, the zoom lens group G2 has negative focal power, the focus lens group G3 has negative focal power, and the second fixed lens group G4 has positive focal power; the first fixed lens group G1 comprises a first lens 101 and a second lens 102, which are arranged in sequence along the optical axis from the object plane to the image plane, the first lens 101 has negative focal power, and the second lens 102 has positive focal power; the zoom lens group G2 comprises a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106, a sixth lens 107, a seventh lens 108, a seventh lens 109, a seventh lens 110, a seventh lens 111, a seventh lens 112, a seventh lens 113, a seventh lens 114, a seventh lens 115, a seventh lens 116, a seventh lens 117, a seventh lens 118, a seventh lens 119, a seventh lens 120 The optical system comprises an optical system comprising: ... The object-side surface of the first lens 101 is convex, and the image-side surface is concave; the object-side surface of the second lens 102 is convex, and the image-side surface is concave; the object-side surface of the third lens 103 is flat, and the image-side surface is concave; the object-side surface of the fourth lens 104 is concave, and the image-side surface is concave; the object-side surface of the fifth lens 105 is convex, and the image-side surface is convex; the object-side surface of the sixth lens 106 is convex, and the image-side surface is concave; the object-side surface of the seventh lens 107 is convex, and the image-side surface is concave; the object-side surface of the eighth lens 108 is convex, and the image-side surface is convex; the object-side surface of the ninth lens 109 is concave, and the image-side surface is concave; the object-side surface of the tenth lens 110 is convex, and the image-side surface is convex; and the object-side surface of the eleventh lens 111 is concave, and the image-side surface is convex. The first lens 101 and the second lens 102 form a cemented lens group; the fourth lens 104 and the fifth lens 105 form the first cemented lens group; the seventh lens 107, the eighth lens 108, and the ninth lens 109 form the second cemented lens group. A stop STO is located in the optical path between the fifth lens 105 and the sixth lens 106, and the flat glass plate CG is located on the image-side surface of the eleventh lens 111.

[0097] Table 1 details 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.

[0098] Table 1 Design values ​​of optical physical parameters of zoom lens

[0099] Surface number Surface type Radius of curvature thickness Material (Nd) Material (Vd) 1 Standard surface 21.705 0.500 1.986 16.484 2 Standard surface 15.551 4.000 1.664 35.484 3 Standard surface 910.383 Zoom interval 1 4 Standard surface Inf 0.740 1.729 54.685 5 Standard surface 6.448 5.000 6 Extended aspheric surface -14.335 1.800 1.544 53.812 7 Extended aspheric surface 35.386 1.400 1.671 19.276 8 Extended aspheric surface -40.186 Zoom interval 2 STO Standard surface Inf Zoom interval 3 10 Standard surface 7.181 1.500 1.755 52.322 11 Standard surface 16.507 0.263 12 Standard surface 5.933 0.500 1.755 52.323 13 Standard surface 3.467 4.000 1.437 95.100 14 Standard surface -7.115 0.500 1.664 35.484 15 Standard surface 10.454 0.080 16 Extended aspheric surface 5.790 2.000 1.544 53.812 17 Extended aspheric surface -26.383 Zoom interval 4 18 Extended aspheric surface -13.475 1.957 1.544 53.812 19 Extended aspheric surface -10.736 3.893 CG Standard surface Inf 0.710 1.517 64.199 21 Standard surface Inf 0.100 IMA Standard surface Inf

[0100] Among them, the surface numbers are numbered according to the surface order of each lens. For example, surface number 1 represents the object side surface of the first lens 101, surface number 2 represents the image side surface of the first lens 101, and so on; the radius of curvature represents the degree of curvature of the lens surface, a positive value represents that the surface is curved toward the image side, a negative value represents that the surface is curved toward the object side, and Inf represents that the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface, and the units of the radius of curvature and thickness are both millimeters (mm); 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, and the refractive index is 1; material (Vd) is the dispersion coefficient, which represents the dispersion characteristics of the material between the current surface and the next surface to the light, and a blank space represents that the current position is air; STO represents the aperture; CG represents flat glass; IMA represents the image surface of the lens.

[0101] Table 2 shows the numerical values ​​of the zoom intervals in Table 1.

[0102] Table 2 Design values ​​of zoom intervals at the wide-angle and telephoto ends of zoom lenses

[0103] Wide-angle end Telephoto end Zoom interval 1 0.235 16.294 Zoom interval 2 16.259 0.200 Zoom interval 3 5.808 0.200 Zoom interval 4 1.337 6.945

[0104] 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:

[0105]

[0106] Where Z is the axial distance from the surface at a height r perpendicular to the optical axis to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; a4, a6, a8, a10, a12, a14, a16, a18, and a20 are the high-order aspheric coefficients of the corresponding aspheric surface, namely, the fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, eighteenth, and twentieth orders. i r i The combination becomes the high-order terms corresponding to the aspheric surface; K is the cone coefficient.

[0107] For example, Table 3 describes in detail the aspheric coefficients of each lens in the first embodiment in a feasible implementation manner.

[0108] Table 3 Design values ​​of aspheric coefficients of each lens in zoom lens

[0109]

[0110]

[0111] Among them, 7.078894621069E-04 means that the coefficient B of face number 6 is 7.078894621069*10 -4 , and so on.

[0112] The zoom lens provided in this embodiment 1 achieves the following technical indicators:

[0113] Table 4 Technical specifications of zoom lenses

[0114] Wide-angle end / telephoto end Image size (mm) Φ4.0 magnification 6.28 Wavelength (nm) 436～850 F / # 1.50 / 3.00 Total lens length (mm) 52.350

[0115] Further, Figure 3 This is the axial aberration diagram of the zoom lens at the wide-angle end provided by the first embodiment of the present invention, with a main wavelength of 546.074 nm. The horizontal direction represents the axial offset relative to the specified target surface, in millimeters (mm). Figure 3 It can be seen that the axial aberrations at different wavelengths and normalized apertures of 0 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of this zoom lens at the wide-angle end is well controlled, meeting the basic requirements for clear night imaging and achieving clear imaging across the entire band.

[0116] Figure 4 This is a ray fan diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end, as shown in FIG. Figure 4 As shown. The ray fan diagram is one of the evaluation methods commonly used by optical designers. In a single diagram, the horizontal axis is the normalized beam diameter, and the vertical axis is the vertical axis aberration. Ideally, each curve should completely coincide with the horizontal axis, and all light rays in the field of view are focused on the same point on the image plane; the vertical axis in a single image can also be expressed as 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. By Figure 4 As can be seen, this zoom lens's curves for all wavelengths in all fields of view are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, the curves for each color have no noticeable dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the lens's ability to produce clear images across the entire wavelength range.

[0117] Figure 5 This is the vertical axis chromatic aberration curve of the zoom lens provided in Example 1 of the present invention at the wide-angle end. The vertical direction represents the normalized field of view, 0 represents the optical axis, and the vertical axis vertex represents the maximum field of view. The main wavelength is 546.074nm, and the horizontal direction represents the offset relative to the main wavelength, in microns (μm). Figure 5 It can be seen that the vertical chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end is well controlled and can meet the needs of wide-spectrum applications across the entire band.

[0118] Figure 6 This is the axial aberration diagram of the zoom lens at the telephoto end provided by the first embodiment of the present invention, with a main wavelength of 546.074 nm. The horizontal direction represents the axial offset relative to the specified target surface, in millimeters (mm). Figure 6 It can be seen that the axial aberrations at different wavelengths of 0 to 1.0 normalized aperture are all controlled within a reasonable range, indicating that the axial chromatic aberration of this zoom lens at the telephoto end is well controlled, meeting the basic requirements for clear night imaging and achieving clear imaging across the entire band.

[0119] Figure 7 This is a ray fan diagram of the zoom lens at the telephoto end provided by the first embodiment of the present invention, as shown in FIG. Figure 7 As shown. The ray fan diagram is one of the evaluation methods commonly used by optical designers. In a single diagram, the horizontal axis is the normalized beam diameter, and the vertical axis is the vertical axis aberration. Ideally, each curve should completely coincide with the horizontal axis, and all light rays in the field of view are focused on the same point on the image plane; the vertical axis in a single image can also be expressed as 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. By Figure 7 As can be seen, this zoom lens's curves for all wavelengths in all fields of view are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, the curves for each color have no noticeable dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the lens's ability to produce clear images across the entire wavelength range.

[0120] Figure 8 This is the vertical axis chromatic aberration curve 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, 0 represents the optical axis, and the vertical axis vertex represents the maximum field of view. The main wavelength is 546.074nm, and the horizontal direction represents the offset relative to the main wavelength, in microns (μm). Figure 8 It can be seen that the vertical chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the vertical chromatic aberration of the zoom lens at the telephoto end is well controlled and can meet the requirements of wide-spectrum applications across the entire wavelength band.

[0121] Example 2

[0122] Figure 9 This is a structural diagram of a zoom lens at the wide-angle end provided by Embodiment 2 of the present invention. Figure 10 This is a structural diagram of a zoom lens at the telephoto end provided by the second embodiment of the present invention, as shown in FIG. Figure 9 and Figure 10As shown, the zoom lens includes a first fixed lens group G1, a zoom lens group G2, a focus lens group G3 and a second fixed lens group G4, which are arranged in sequence along the optical axis from the object plane to the image plane; the first fixed lens group G1 has positive focal power, the zoom lens group G2 has negative focal power, the focus lens group G3 has negative focal power, and the second fixed lens group G4 has positive focal power; the first fixed lens group G1 includes a first lens 201 and a second lens 202, which are arranged in sequence along the optical axis from the object plane to the image plane, the first lens 201 has negative focal power, and the second lens 202 has positive focal power; the zoom lens group G2 includes a third lens 203, a fourth lens 204, which are arranged in sequence along the optical axis from the object plane to the image plane The optical system comprises the following components: lens 1204 and the fifth lens 205, the third lens 203 has negative optical power, the fourth lens 204 has negative optical power, and the fifth lens 205 has positive optical power; the focusing lens comprises a sixth lens 206, a seventh lens 207, an eighth lens 208, a ninth lens 209 and a tenth lens 210 arranged in sequence along the optical axis from the object plane to the image plane, the sixth lens 206 has positive optical power, the seventh lens 207 has negative optical power, the eighth lens 208 has positive optical power, the ninth lens 209 has negative optical power, and the tenth lens 210 has positive optical power; the second fixed lens group G4 comprises an eleventh lens 211, and the eleventh lens 211 has positive optical power. The object-side surface of the first lens 101 is convex, and the image-side surface is concave; the object-side surface of the second lens 102 is convex, and the image-side surface is flat; the object-side surface of the third lens 103 is convex, and the image-side surface is concave; the object-side surface of the fourth lens 104 is concave, and the image-side surface is concave; the object-side surface of the fifth lens 105 is convex, and the image-side surface is convex; the object-side surface of the sixth lens 106 is convex, and the image-side surface is concave; the object-side surface of the seventh lens 107 is convex, and the image-side surface is concave; the object-side surface of the eighth lens 108 is convex, and the image-side surface is convex; the object-side surface of the ninth lens 109 is concave, and the image-side surface is concave; the object-side surface of the tenth lens 110 is convex, and the image-side surface is convex; and the object-side surface of the eleventh lens 111 is concave, and the image-side surface is convex. The first lens 201 and the second lens 202 form a cemented lens group; the fourth lens 104 and the fifth lens 205 form the first cemented lens group; the seventh lens 207, the eighth lens 208, and the ninth lens 209 form the second cemented lens group. A stop STO is located in the optical path between the fifth lens 205 and the sixth lens 206, and the flat glass CG is located on the image-side surface of the eleventh lens 211.

[0123] 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 9 and Figure 10 Zoom lens shown.

[0124] Table 5 Design values ​​of optical physical parameters of zoom lens

[0125]

[0126]

[0127] Among them, the surface numbers are numbered according to the surface order of each lens, for example, surface number 1 represents the object side surface of the first lens 201, surface number 2 represents the image side surface of the first lens 201, and so on; the radius of curvature represents the degree of curvature of the lens surface, a positive value represents that the surface is curved toward the image side, a negative value represents that the surface is curved toward the object side, and Inf represents that the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface, and the units of the radius of curvature and thickness are both millimeters (mm); 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, and the refractive index is 1; material (Vd) is the dispersion coefficient, 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; STO represents the aperture; CG represents flat glass; IMA represents the image surface of the lens.

[0128] Table 6 shows the numerical values ​​of the zoom intervals in Table 5.

[0129] Table 6 Design values ​​of zoom intervals at the wide-angle and telephoto ends of zoom lenses

[0130]

[0131]

[0132] 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:

[0133]

[0134] Where Z is the axial distance from the surface at a height r perpendicular to the optical axis to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; a4, a6, a8, a10, a12, a14, a16, a18, and a20 are the high-order aspheric coefficients of the corresponding aspheric surface, namely, the fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, eighteenth, and twentieth orders. i r i The combination becomes the high-order terms corresponding to the aspheric surface; K is the cone coefficient.

[0135] For example, Table 7 describes in detail the aspheric coefficients of each lens in the second embodiment in a feasible implementation manner.

[0136] Table 7 Design values ​​of aspheric coefficients of each lens in the zoom lens

[0137]

[0138]

[0139] Among them, 8.411731653473E-04 means that the coefficient B of face number 6 is 8.411731653473*10 -4 , and so on.

[0140] The zoom lens provided in the second embodiment achieves the following technical indicators:

[0141] Table 8 Technical specifications of zoom lenses

[0142] Wide-angle end / telephoto end Image size (mm) Φ4.0 magnification 6.45 Wavelength (nm) 436～850 F / # 1.49～3.01 Total lens length (mm) 52.371

[0143] Further, Figure 11 This is the axial aberration diagram of the zoom lens at the wide-angle end provided by the second embodiment of the present invention, with a main wavelength of 546.074 nm. The horizontal direction represents the axial offset relative to the specified target surface, in millimeters (mm). Figure 11 It can be seen that the axial aberrations at different wavelengths and normalized apertures of 0 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of this zoom lens at the wide-angle end is well controlled, meeting the basic requirements for clear night imaging and achieving clear imaging across the entire band.

[0144] Figure 12 This is a ray fan diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end, as shown in FIG. Figure 12 As shown. The ray fan diagram is one of the evaluation methods commonly used by optical designers. In a single diagram, the horizontal axis is the normalized beam diameter, and the vertical axis is the vertical axis aberration. Ideally, each curve should completely coincide with the horizontal axis, and all light rays in the field of view are focused on the same point on the image plane; the vertical axis in a single image can also be expressed as 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. By Figure 12 As can be seen, this zoom lens's curves for all wavelengths in all fields of view are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, the curves for each color have no noticeable dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the lens's ability to produce clear images across the entire wavelength range.

[0145] Figure 13 This is the vertical axis chromatic aberration curve of the zoom lens provided in Example 2 of the present invention at the wide-angle end. The vertical direction represents the normalized field of view, 0 represents the optical axis, and the vertical axis vertex represents the maximum field of view. The main wavelength is 546.074nm, and the horizontal direction represents the offset relative to the main wavelength, in microns (μm). Figure 13It can be seen that the vertical chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end is well controlled and can meet the needs of wide-spectrum applications across the entire band.

[0146] Figure 14 This is the axial aberration diagram of the zoom lens at the telephoto end provided by the second embodiment of the present invention, with a main wavelength of 546.074 nm, and the horizontal direction represents the axial offset relative to the specified target surface, in millimeters (mm). Figure 14 It can be seen that the axial aberrations at different wavelengths of 0 to 1.0 normalized aperture are all controlled within a reasonable range, indicating that the axial chromatic aberration of this zoom lens at the telephoto end is well controlled, meeting the basic requirements for clear night imaging and achieving clear imaging across the entire band.

[0147] Figure 15 This is a ray fan diagram of the zoom lens at the telephoto end provided by the second embodiment of the present invention, as shown in FIG. Figure 15 As shown. The ray fan diagram is one of the evaluation methods commonly used by optical designers. In a single diagram, the horizontal axis is the normalized beam diameter, and the vertical axis is the vertical axis aberration. Ideally, each curve should completely coincide with the horizontal axis, and all light rays in the field of view are focused on the same point on the image plane; the vertical axis in a single image can also be expressed as 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. By Figure 15 As can be seen, this zoom lens's curves for all wavelengths in all fields of view are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, the curves for each color have no noticeable dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the lens's ability to produce clear images across the entire wavelength range.

[0148] Figure 16 This is the vertical axis chromatic aberration curve of the zoom lens at the telephoto end provided by Example 2 of the present invention. The vertical direction represents the normalized field of view, 0 represents the optical axis, and the vertical axis vertex represents the maximum field of view. The main wavelength is 546.074nm, and the horizontal direction represents the offset relative to the main wavelength, in microns (μm). Figure 16 It can be seen that the vertical chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the vertical chromatic aberration of the zoom lens at the telephoto end is well controlled and can meet the requirements of wide-spectrum applications across the entire wavelength band.

[0149] Example 3

[0150] Figure 17 This is a schematic structural diagram of a zoom lens at the wide-angle end provided by Embodiment 3 of the present invention. Figure 18 This is a structural diagram of a zoom lens at the telephoto end provided by the third embodiment of the present invention, as shown in FIG. Figure 17 and Figure 18 As shown, the zoom lens includes a first fixed lens group G1, a zoom lens group G2, a focus lens group G3 and a second fixed lens group G4, which are arranged in sequence along the optical axis from the object plane to the image plane; the first fixed lens group G1 has positive focal power, the zoom lens group G2 has negative focal power, the focus lens group G3 has negative focal power, and the second fixed lens group G4 has positive focal power; the first fixed lens group G1 includes a first lens 301 and a second lens 302, which are arranged in sequence along the optical axis from the object plane to the image plane, the first lens 301 has negative focal power, and the second lens 302 has positive focal power; the zoom lens group G2 includes a third lens 303, a fourth lens 304, which are arranged in sequence along the optical axis from the object plane to the image plane The optical system comprises an optical system comprising: ... The object-side surface of the first lens 101 is convex, and the image-side surface is concave; the object-side surface of the second lens 102 is convex, and the image-side surface is concave; the object-side surface of the third lens 103 is convex, and the image-side surface is concave; the object-side surface of the fourth lens 104 is concave, and the image-side surface is concave; the object-side surface of the fifth lens 105 is convex, and the image-side surface is convex; the object-side surface of the sixth lens 106 is convex, and the image-side surface is concave; the object-side surface of the seventh lens 107 is convex, and the image-side surface is concave; the object-side surface of the eighth lens 108 is convex, and the image-side surface is convex; the object-side surface of the ninth lens 109 is concave, and the image-side surface is concave; the object-side surface of the tenth lens 110 is convex, and the image-side surface is convex; and the object-side surface of the eleventh lens 111 is concave, and the image-side surface is convex. The first lens 301 and the second lens 302 form a cemented lens group; the fourth lens 304 and the fifth lens 305 form the first cemented lens group; the seventh lens 307, the eighth lens 108, and the ninth lens 309 form the second cemented lens group. A stop STO is located in the optical path between the fifth lens 305 and the sixth lens 306, and the flat glass CG is located on the image-side surface of the eleventh lens 311.

[0151] Table 9 details 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 17 and Figure 18 Zoom lens shown.

[0152] Table 9 Design values ​​of optical physical parameters of zoom lens

[0153]

[0154]

[0155] Among them, the surface numbers are numbered according to the surface order of each lens, for example, surface number 1 represents the object side surface of the first lens 301, surface number 2 represents the image side surface of the first lens 301, and so on; the radius of curvature represents the degree of curvature of the lens surface, a positive value represents that the surface is curved toward the image side, a negative value represents that the surface is curved toward the object side, and Inf represents that the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface, and the units of the radius of curvature and thickness are both millimeters (mm); 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, and the refractive index is 1; material (Vd) is the dispersion coefficient, which represents the dispersion characteristics of the light between the material between the current surface and the next surface, and a blank space represents that the current position is air; STO represents the aperture; CG represents flat glass; IMA represents the image surface of the lens.

[0156] Table 10 shows the numerical values ​​of the zoom intervals in Table 9.

[0157] Table 9 Design values ​​of zoom intervals at the wide-angle and telephoto ends of zoom lenses

[0158] Wide-angle end Telephoto end Zoom interval 1 1.041 16.315 Zoom interval 2 15.474 0.199 Zoom interval 3 4.397 0.231 Zoom interval 4 2.748 6.914

[0159] 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:

[0160]

[0161] Where Z is the axial distance from the surface at a height r perpendicular to the optical axis to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; a4, a6, a8, a10, a12, a14, a16, a18, and a20 are the high-order aspheric coefficients of the corresponding aspheric surface, namely, the fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, eighteenth, and twentieth orders. i r i The combination becomes the high-order terms corresponding to the aspheric surface; K is the cone coefficient.

[0162] For example, Table 11 describes in detail the aspheric coefficients of each lens in Example 3 in a feasible implementation manner.

[0163] Table 11 Design values ​​of aspheric coefficients of each lens in zoom lens

[0164]

[0165] Among them, 8.584573774925E-05 means that the coefficient B of face number 6 is 8.584573774925*10 -5 , and so on.

[0166] The zoom lens provided in the third embodiment achieves the following technical indicators:

[0167] Table 12 Technical specifications of zoom lenses

[0168] Wide-angle end / telephoto end Image size (mm) Φ4.0 magnification 5.98 Wavelength (nm) 436～850 F / # 1.49～3.01 Total lens length (mm) 52.371

[0169] Further, Figure 19 This is the axial aberration diagram of the zoom lens at the wide-angle end provided by the third embodiment of the present invention, with a main wavelength of 546.074 nm. The horizontal direction represents the axial offset relative to the specified target surface, in millimeters (mm). Figure 19 It can be seen that the axial aberrations at different wavelengths and normalized apertures of 0 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of this zoom lens at the wide-angle end is well controlled, meeting the basic requirements for clear night imaging and achieving clear imaging across the entire band.

[0170] Figure 20 This is a ray fan diagram of the zoom lens provided in the third embodiment of the present invention at the wide-angle end, as shown in FIG. Figure 20 As shown. The ray fan diagram is one of the evaluation methods commonly used by optical designers. In a single diagram, the horizontal axis is the normalized beam diameter, and the vertical axis is the vertical axis aberration. Ideally, each curve should completely coincide with the horizontal axis, and all light rays in the field of view are focused on the same point on the image plane; the vertical axis in a single image can also be expressed as 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. By Figure 20 As can be seen, this zoom lens's curves for all wavelengths in all fields of view are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, the curves for each color have no noticeable dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the lens's ability to produce clear images across the entire wavelength range.

[0171] Figure 21 This is the vertical axis chromatic aberration curve of the zoom lens provided in Example 3 of the present invention at the wide-angle end. The vertical direction represents the normalized field of view, 0 represents the optical axis, and the vertical axis vertex represents the maximum field of view. The main wavelength is 546.074nm, and the horizontal direction represents the offset relative to the main wavelength, in microns (μm). Figure 21 It can be seen that the vertical chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end is well controlled and can meet the needs of wide-spectrum applications across the entire band.

[0172] Figure 22 This is the axial aberration diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention, with a main wavelength of 546.074 nm. The horizontal direction represents the axial offset relative to the specified target surface, in millimeters (mm). Figure 22 It can be seen that the axial aberrations at different wavelengths of 0 to 1.0 normalized aperture are all controlled within a reasonable range, indicating that the axial chromatic aberration of this zoom lens at the telephoto end is well controlled, meeting the basic requirements for clear night imaging and achieving clear imaging across the entire band.

[0173] Figure 23 This is a ray fan diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention, as shown in FIG. Figure 23 As shown. The ray fan diagram is one of the evaluation methods commonly used by optical designers. In a single diagram, the horizontal axis is the normalized beam diameter, and the vertical axis is the vertical axis aberration. Ideally, each curve should completely coincide with the horizontal axis, and all light rays in the field of view are focused on the same point on the image plane; the vertical axis in a single image can also be expressed as 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. By Figure 23 As can be seen, this zoom lens's curves for all wavelengths in all fields of view are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, the curves for each color have no noticeable dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the lens's ability to produce clear images across the entire wavelength range.

[0174] Figure 24 This is the vertical axis chromatic aberration curve of the zoom lens at the telephoto end provided by Example 3 of the present invention. The vertical direction represents the normalized field of view, 0 represents the optical axis, and the vertical axis vertex represents the maximum field of view; the main wavelength is 546.074nm, and the horizontal direction represents the offset relative to the main wavelength, in microns (μm). Figure 24 It can be seen that the vertical chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the vertical chromatic aberration of the zoom lens at the telephoto end is well controlled and can meet the requirements of wide-spectrum applications across the entire wavelength band.

[0175] 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.

[0176] Table 13 Design values ​​of optical physical parameters of zoom lens

[0177] Scope of protection Example 1 Example 2 Example 3 Lower limit Upper limit F1 / FW 12.763 18.684 18.253 12.00 18.50 F2 / FW -19.323 -23.112 -20.161 -23.50 -19.00 F3 / FW -7.140 -12.826 -17.372 -17.50 -7.00 F4 / FW 23.955 2.908 2.087 2.00 24.00 F45FW -19.32 -20.16 -20.16 -20.50 -19.00 F789 / FW -7.14 -17.37 -17.37 -17.50 -7.00 H / TAN(θW) 3.33 2.99 2.99 2.95 3.50 H / TAN(θT) 21.871 18.398 18.240 18.00 22.00 S2 / S3 2.864 3.505 3.666 2.80 3.70 ΦG1 / TTLW 0.33 0.50 0.50 0.30 0.50 FW / EPDW 1.499 1.499 1.432 1.43 1.50 Nd4 1.557 1.547 1.547 1.54 1.56 Nd5 1.720 1.706 1.706 1.70 1.72 Nd8 1.443 1.505 1.505 1.43 1.51 Nd11 1.557 1.547 1.547 1.54 1.56 Vd4 53.812 55.711 55.711 53.5 56.00 Vd5 19.276 20.382 20.382 19.00 21.00 Vd8 95.100 81.608 81.608 80.00 96.00 Vd11 53.812 55.711 55.711 53.50 56.00 Nd1 1.986 2.051 2.001 1.98 2.06 Vd1 16.484 26.986 25.458 16.00 27.50

[0178] 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 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 from the object plane to the image plane along the optical axis; The first fixed lens group and the second fixed lens group are fixed, and the zoom lens group and the focus lens group are movable along the optical axis; The first fixed lens group has positive optical power, the zoom lens group has negative optical power, the focus lens group has negative optical power, and the second fixed lens group has positive optical power; The first fixed lens group includes a first lens and a second lens arranged in sequence along the optical axis 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 along the optical axis from the object plane to the image plane, the third lens having negative optical power, the fourth lens having negative optical power, and the fifth lens having 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 along the optical axis from the object plane to the image plane, the sixth lens having positive focal power, the seventh lens having negative focal power, the eighth lens having positive focal power, the ninth lens having negative focal power, and the tenth lens having positive focal power; The second fixed lens group includes an eleventh lens having positive refractive power.

2. The zoom lens according to claim 1, wherein: The focal length of the first fixed lens group is F1, the focal length of the zoom lens group is F2, the focal length of the focus lens group is F3, the focal length of the second fixed lens group is F4, and the focal length of the zoom lens at the wide-angle end is FW; wherein, 12.00≤F1 / FW≤18.50; -23.50≤F2 / FW≤-19.00; -17.50≤F3 / FW≤-7.00; 2.00≤F4 / FW≤24.

00.

3. The zoom lens according to claim 1, wherein: The maximum movable distance of the zoom lens group is S2, and the maximum movable distance of the focus lens group is S3; wherein, 0.85≤S2 / S3≤0.

90.

4. The zoom lens according to claim 1, wherein: The fourth lens and the fifth lens form a first cemented lens group; the seventh lens, the eighth lens and the ninth lens form a second cemented lens group; The focal length of the first cemented lens group in the zoom lens group is F45, the focal length of the second cemented lens group in the focus lens group is F789, and the focal length of the zoom lens at the wide-angle end is FW; wherein, -20.50≤F45 / FW≤-19.00; -17.50≤F789 / FW≤-7.

00.

5. The zoom lens according to claim 1, wherein: The refractive index of the first lens is Nd1, and the Abbe number is Vd1; the refractive index of the fourth lens is Nd4, and the Abbe number is Vd4; the refractive index of the fifth lens is Nd5, and the Abbe number is Vd5; the refractive index of the eighth lens is Nd8, and the Abbe number is Vd8; the refractive index of the eleventh lens is Nd11, and the Abbe number is Vd11, wherein: 1.98≤Nd1≤2.06;16.00≤Vd1≤27.50; 1.54≤Nd4≤1.56;53.50≤Vd4≤56.00; 1.70≤Nd5≤1.72, 19.00≤Vd5≤51.00; 1.43≤Nd8≤1.51;80.00≤Vd8≤96.00; 1.54≤Nd11≤1.56;53.50≤Vd11≤56.

00.

6. The zoom lens according to claim 1, wherein: The focal length of the zoom lens at the wide-angle end is FW, and the entrance pupil diameter of the zoom lens at the wide-angle end is EPDW; wherein, 1.43≤FW / EPDW≤1.

50.

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 at the wide-angle end is TTL; wherein 10.62≤ΦG1 / TTL≤12.

60.

8. The zoom lens according to claim 1, wherein: At least one plastic aspherical lens is provided in the zoom lens group and the focus lens group; The eleventh lens is a plastic aspherical lens.

9. The zoom lens according to claim 1, wherein: The zoom lens further includes an aperture stop, and the aperture stop is located between the zoom lens group and the focus lens group.

10. A lens module, characterized in that: The lens module comprises a photosensitive chip and the zoom lens according to any one of claims 1 to 9, wherein the photosensitive chip is arranged on the image plane side of the zoom lens; The diagonal length of the photosensitive chip is H, the tangent value of the incident angle of the zoom lens at the wide-angle end is TAN(θW), and the tangent value of the incident angle of the zoom lens at the telephoto end is TAN(θT); wherein, 2.95≤H / TAN(θW)≤3.50; 18.00≤H / TAN(θT)≤22.00.

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