Zoom lens and lens module

Abstract

The application 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 refractive power, the second lens has positive refractive power, the third lens has negative refractive power, the fourth lens has negative refractive power, the fifth lens has positive refractive power, 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, the tenth lens has positive refractive power, and the eleventh lens has positive refractive power. Therefore, the zoom lens can ensure that the zoom lens is in focus in the full wave band, has a smaller volume, a larger aperture and higher image quality, and meets more extensive use requirements.

Description

Technical Field

[0001] This invention relates to the field of optical device technology, and in particular to a zoom lens and lens module. Background Technology

[0002] In the security field, zoom lenses have been widely used due to their advantages such as long shooting distance and wide shooting angle. With the development of technology, cameras are gradually moving towards miniaturization and refinement, which also puts forward more stringent requirements for mainstream zoom lenses.

[0003] Existing zoom lenses using 1 / 4" target surfaces are widely used in places where standard-sized zoom lenses or PTZ cameras cannot be accommodated due to their advantages such as the smallest size, lightest weight, and high cost performance. However, 1 / 4" zoom lenses on the market generally have drawbacks such as low zoom ratio, small F number, and inability to be used at night. Summary of the Invention

[0004] This invention provides a zoom lens and lens module to solve the problem of zoom lenses with high magnification, large aperture, and infrared confocal focus.

[0005] In a first aspect, the present invention provides a zoom lens, comprising a first fixed lens group, a zoom lens group, a focusing lens group, and a second fixed lens group arranged sequentially along the optical axis from the object plane to the image plane;

[0006] The first fixed lens group and the second fixed lens group are fixedly disposed, while the zoom lens group and the focusing 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 focusing 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 sequentially along the optical axis from the object plane to the image plane. The first lens has negative optical power, and the second lens has positive optical power.

[0009] The zoom lens group includes a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis 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 sequentially along the optical axis from the object plane to the image plane. The sixth lens has positive optical power, the seventh lens has negative optical power, the eighth lens has positive optical power, the ninth lens has negative optical power, and the tenth lens has positive optical power.

[0011] The second fixed lens group includes an eleventh lens, which has positive optical 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 focusing 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 focusing lens group is S3; wherein, 2.80≤S2 / S3≤3.70.

[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 zoom lens group has a focal length of F45 for the first cemented lens group and an focal length of F789 for the second cemented lens group in the focusing lens group; the zoom lens has a focal length of FW at the wide-angle end.

[0020] -20.50≤F45 / FW≤-19.00;

[0021] -17.50≤F789 / FW≤-7.00.

[0022] Optionally, the first lens has a refractive index of Nd1 and an Abbe number of Vd1; the fourth lens has a refractive index of Nd4 and an Abbe number of Vd4; the fifth lens has a refractive index of Nd5 and an Abbe number of Vd5; the eighth lens has a refractive index of Nd8 and an Abbe number of Vd8; and the eleventh lens has a refractive index of Nd11 and an Abbe number of 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] 0.30≤ΦG1 / TTL≤0.50.

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

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

[0034] Optionally, the zoom lens further includes an aperture stop located between the zoom lens group and the focusing lens group.

[0035] In a second aspect, the present invention provides a lens module, the lens module including a photosensitive chip and a zoom lens as described in any one of the first aspects, the photosensitive chip being disposed on the image plane side of the zoom lens;

[0036] The diagonal length of the photosensitive chip is H, the tangent of the incident angle at the wide-angle end of the zoom lens is TAN(θW), and the tangent of the incident angle at the telephoto end of the zoom lens 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 this invention, through the zoom lens provided by this 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 matching of the four lens groups and the 11 lenses, a zoom lens with full focal length confocal in the 436nm-850nm band under a 1 / 4″ target surface is achieved, which is smaller in size, larger in aperture and higher in image quality.

[0040] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the structure of a zoom lens at the wide-angle end according to an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the structure 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 at the wide-angle end provided in Embodiment 1 of the present invention;

[0045] Figure 4 This is a ray fan diagram of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention;

[0046] Figure 5 The lateral chromatic aberration curve of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention;

[0047] Figure 6 This is an axial aberration diagram of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention;

[0048] Figure 7 This is a ray fan diagram of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention;

[0049] Figure 8 The vertical chromatic aberration curve of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention;

[0050] Figure 9 This is a schematic diagram of the structure of a zoom lens at the wide-angle end according to Embodiment 2 of the present invention;

[0051] Figure 10 This is a schematic diagram of the structure of a zoom lens at the telephoto end according to Embodiment 2 of the present invention;

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

[0053] Figure 12 This is a ray fan diagram of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention;

[0054] Figure 13 The transverse chromatic aberration curve of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention

[0055] Figure 14 This is an axial aberration diagram of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention;

[0056] Figure 15 This is a ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention;

[0057] Figure 16 This is the vertical chromatic aberration curve of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention;

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

[0059] Figure 18 This is a schematic diagram of the structure of a zoom lens at the telephoto end according to Embodiment 3 of the present invention;

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

[0061] Figure 20 This is a ray fan diagram of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

[0062] Figure 21 The vertical chromatic aberration curve of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

[0063] Figure 22 This is an axial aberration diagram of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention;

[0064] Figure 23 This is a ray fan diagram of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention;

[0065] Figure 24 This is the vertical chromatic aberration curve of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention. Detailed Implementation

[0066] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0067] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

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

[0069] For example, in the zoom lens provided in this embodiment, the first fixed lens group G1, the zoom lens group G2, the focusing lens group G3, and the second fixed lens group G4 can be disposed in one lens barrel. Figure 1 (Not shown in the image). The first fixed lens group G1 and the second fixed lens group G4 are fixed in position within the lens barrel. The zoom lens group G2 and the focusing 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 focusing lens group G3, the focal length of the zoom lens can be continuously varied from wide-angle to telephoto, ensuring high image quality at all focal points while maintaining the miniaturization of the zoom lens.

[0070] It is understandable that during the zoom process achieved by moving the zoom lens group G2 and the focusing lens group G3, the zoom lens is at its shortest focal length, which is when it is at the wide-angle end, and at its longest focal length, which is when it is at the telephoto end. At the wide-angle end and the telephoto end, the zoom lens has different focal lengths and optical powers, as well as different lengths or shapes.

[0071] Furthermore, optical power is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam; it characterizes the ability of an optical system to deflect light rays. The larger the absolute value of the optical power, the stronger the bending ability of light rays; the smaller the absolute value, the weaker the bending ability. When the optical power is positive, the refraction of light rays is converging; when the optical power is negative, the refraction of light rays is diverging. Optical power can be used to characterize a single refractive surface of a lens (i.e., one surface of the lens), a single lens, or a system formed by multiple lenses (i.e., a lens group).

[0072] In this embodiment, by setting the first fixed lens group G1 to have positive optical power, the zoom lens group G2 to have negative optical power, the focusing lens group G3 to have negative optical power, and the second fixed lens group G4 to have positive optical power, the optical powers of the first fixed lens group G1, the zoom lens group G2, the focusing lens group G3, and the second fixed lens group G4 are coordinated to compensate for aberrations caused by the zoom movement of the zoom lens group G2 and the focusing lens group G3, ensuring image clarity at different focal lengths.

[0073] Furthermore, 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, arranged sequentially along the optical axis from the object plane to the image plane. The first lens 101, with its negative optical power, can widen the incident light beam, allowing more light to enter the subsequent lens group, thus facilitating a larger aperture. The second lens 102, with its positive optical power, combines a negative lens and a positive lens, which helps control the light path, allowing it to pass through the subsequent lens group more smoothly. It also helps to counteract each other's dispersion effects, reducing chromatic aberration. It should be noted that by using fewer lenses, the first fixed lens group G1 can reduce the weight and size of the lens. Simultaneously, it can reduce the number of times light passes through the air-glass interface, thereby reducing reflection loss 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 in this embodiment of the invention uses only 11 lenses, which helps to reduce the lens length to less than 53mm. Simultaneously, by rationally combining the optical power of these 11 lenses, aberrations can be effectively corrected, achieving an ultra-wide-angle zoom lens with a large aperture (F1.49~F3.01) and full-range infrared confocal focusing. This allows for the use of 1 / 1.4" large-area photosensitive chips, thus meeting the needs of large-scale security monitoring.

[0075] In summary, this invention provides a four-element zoom lens, comprising a first fixed lens group G1, a zoom lens group G2, a focusing lens group G3, and a second fixed lens group G4 arranged sequentially along the optical axis from the object plane to the image plane. Specifically, it employs 11 lenses, a relatively small number that helps reduce lens length. By rationally combining the first fixed lens group G1, the zoom lens group G2, the focusing lens group G3, and the second fixed lens group G4, along with the optical power of each lens, aberrations can be effectively corrected, ensuring image clarity at different focal lengths. Simultaneously, this zoom lens offers the advantages of small size, large aperture, and wide aperture range, meeting a wider range of usage needs.

[0076] As one possible implementation method, please refer to [reference]. 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 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.

[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; 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 the lens affects the direction of light propagation, determining how light bends as it passes through the lens, thus affecting the lens's maximum aperture and light transmission, as well as the image quality and characteristics.

[0078] In this embodiment, by designing the surface shape of each lens and combining the optical power of each lens, the imaging effect of the zoom lens can be further adjusted.

[0079] As one possible implementation, 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 focusing lens group G3 is F3, the focal length of the second fixed lens group G4 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. Using this lens configuration achieves a reasonable balance of optical power, allowing light to pass through the lens more smoothly and significantly correcting the impact of higher-order 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 focusing lens group G3 is S3; wherein, 2.80≤S2 / S3≤3.70. By controlling the stroke ratio of the zoom lens group G2 and the focusing lens group G3 during their movement, efficient utilization of the moving areas of the zoom lens group G2 and the focusing lens group G3 is achieved, minimizing the lens size to the greatest extent.

[0081] In one possible implementation, at least one plastic aspherical lens is provided in the zoom lens group G2 and the focusing lens group G3; the eleventh lens 111 is a plastic aspherical lens. In the zoom lens group G2, the fourth lens 104 and the fifth lens 105 are both plastic aspherical lenses, and the third lens 103 is a glass spherical lens; in the focusing lens group G3, the tenth lens 110 is a plastic aspherical lens, and the sixth lens 106, the seventh lens 107, the eighth lens 108, and the ninth lens 109 are all glass spherical lenses; in the first fixed lens group G1, the first lens 101 and the second lens 102 are both glass spherical lenses; and in the second fixed lens group G4, the eleventh lens 111 is a glass spherical lens. The cost of plastic lenses is much lower than that of glass lenses, which can reduce the cost of zoom lenses. At the same time, glass and plastic materials can compensate for each other, balancing high and low temperatures and reducing the overall length of the lens, giving the zoom lens stable performance at high and low temperatures and improving its environmental adaptability.

[0082] In one possible implementation, 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 focusing 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; -17.50≤F789 / FW≤-7.00. By using the fourth lens 104 and the fifth lens 105 to form the first cemented lens group, and the seventh lens 107, the eighth lens 108, and the ninth lens 109 to form the second cemented lens group, the air gap between the fourth lens 104 and the fifth lens 105, as well as the air gap 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. Cemented lenses can effectively correct aberrations produced by the lens. Using cemented lenses in the zoom lens group G2 and the focusing lens group G3 ensures aberration balance during zooming, improving image quality. Furthermore, cemented lens groups can simultaneously expand the lens's degrees of freedom, enabling the cementation between the two aspherical surfaces in the fourth lens 104 and the fifth lens 105, further controlling higher-order aberrations. The energy absorption of the cemented layer also provides better shock resistance, meeting the needs of use in complex environments. Compared to a cemented doublet consisting of the fourth lens 104 and the fifth lens 105, a cemented triplet consisting of the seventh lens 107, the eighth lens 108, and the ninth lens 109 offers even better high-order aberration correction capabilities, improving image quality.

[0083] As one possible implementation, the zoom lens also includes an aperture stop STO, which is located between the zoom lens group G2 and the focusing lens group G3. By adding the aperture stop STO, the propagation direction of the light beam can be adjusted, which is beneficial for improving image quality. The aperture stop 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 stop STO is not limited in this embodiment of the invention.

[0084] In one possible implementation, the first lens 101 has a refractive index of Nd1 and an Abbe number of Vd1; the fourth lens 104 has a refractive index of Nd4 and an Abbe number of Vd4; the fifth lens 105 has a refractive index of Nd5 and an Abbe number of Vd5; the eighth lens 108 has a refractive index of Nd8 and an Abbe number of Vd8; and the eleventh lens 111 has a refractive index of Nd11 and an Abbe number of 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 is mainly used to describe a material's ability to refract light; different materials have different refractive indices. The Abbe number is an index used to represent the dispersion ability of a transparent medium. The more severe the dispersion of the medium, the smaller the Abbe number; conversely, the less severe the dispersion, the larger the Abbe number. Therefore, by carefully selecting the refractive index and Abbe number of each lens in a zoom lens, it is beneficial to achieve miniaturization of the zoom lens; at the same time, it is beneficial to achieve higher pixel resolution and a larger aperture.

[0086] In zoom lenses, the use of high-refractive-index materials in the first lens 101 can better control the edge light at the wide-angle end, avoiding severe coma and distortion. In addition, it can control the curvature of the first lens 101, reduce Fresnel reflection, improve the relative illumination of the lens, and avoid problems such as vignetting. Furthermore, the use of high-refractive-index materials in the first lens 101 can effectively reduce the group volume, achieving the goal of miniaturization of the group.

[0087] In zoom lenses, the zoom lens group G2 before the aperture stop STO plays a dominant role in adjusting the lens magnification. Using materials with the aforementioned refractive index, combined with the lens's optical power, it corrects aberrations and controls the lens's high and low temperature conditions. Simultaneously, using the fourth lens 104 and the fifth lens 105, also made of the aforementioned materials, to form a cemented lens group not only ensures aberration balance but also offers advantages in group size and dimensions. Furthermore, it increases the lens's F-number, improving image illumination. The eighth lens 108, the middle lens in the triplet cemented lens group, uses a high Abbe number material to act as a "dispersion buffer layer" for the cemented lens, breaking the continuous superposition effect of the high-dispersion materials on both sides, forming a dispersion-anti-dispersion-dispersion compensation chain, ensuring image quality. The eleventh lens 111 in the second fixed lens group G4, using materials with the aforementioned refractive index, can better control the light emission angle of the zoom lens, thus controlling image quality and target surface size.

[0088] As one possible implementation, 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 one possible implementation, 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, 0.30≤ΦG1 / TTL≤0.50.

[0090] The entrance pupil diameter (EPDW) of a zoom lens at the wide-angle end can be understood as the diameter of the image formed by the aperture stop (STO) relative to its front lens group at the wide-angle end. The aperture stop (STO) of the zoom lens is fixed between the zoom lens group G2 and the focusing lens group G3, which can symmetrically distribute aberrations, correct field curvature while controlling lens distortion, and also suppress coma to some extent. Furthermore, the fixed position of the aperture stop (STO) ensures that the angle of incidence of light remains relatively stable during zooming, avoiding abrupt changes in aberration type (such as coma at the wide-angle end changing to spherical aberration at the telephoto end), and providing better control over image 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 aperture stop (STO) relative to its front lens group, and in conjunction with the ratio of the largest 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, achieving the technical goal of a large aperture.

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

[0092] This invention also provides a lens module, which includes a photosensitive chip and a zoom lens as described in any of the above embodiments, wherein the photosensitive chip is disposed on the image plane side of the zoom lens;

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

[0094] The following describes in further detail, with reference to the accompanying drawings, specific embodiments of the zoom lens applicable to the above-described embodiments.

[0095] Example 1

[0096] Continue to refer to Figure 1 and Figure 2The zoom lens includes a first fixed lens group G1, a zoom lens group G2, a focusing lens group G3, and a second fixed lens group G4 arranged sequentially along the optical axis from the object plane to the image plane. The first fixed lens group G1 has positive optical power, the zoom lens group G2 has negative optical power, the focusing lens group G3 has negative optical power, and the second fixed lens group G4 has positive optical power. The first fixed lens group G1 includes a first lens 101 and a second lens 102 arranged sequentially along the optical axis from the object plane to the image plane. The first lens 101 has negative optical power, and the second lens 102 has positive optical power. The zoom lens group G2 includes a third lens 103 and a fourth lens 104 arranged sequentially along the optical axis from the object plane to the image plane. Lens 104 and fifth lens 105; third lens 103 has negative optical power; fourth lens 104 has negative optical power; fifth lens 105 has positive optical power; focusing lens includes a sixth lens 106, a seventh lens 107, an eighth lens 108, a ninth lens 109, and a tenth lens 110 arranged sequentially along the optical axis from the object plane to the image plane; sixth lens 106 has positive optical power; seventh lens 107 has negative optical power; eighth lens 108 has positive optical power; ninth lens 109 has negative optical power; tenth lens 110 has positive optical power; second fixed lens group G4 includes an eleventh lens 111, which 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 concave; the object-side surface of the third lens 103 is planar, 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; 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 a first cemented lens group; the seventh lens 107, the eighth lens 108, and the ninth lens 109 form a second cemented lens group. The aperture stop STO is located in the optical path between the fifth lens 105 and the sixth lens 106, and the flat glass CG is located on the image side of the eleventh lens 111.

[0097] Table 1 details the specific optical physical parameters of each lens in the zoom lens provided in Embodiment 1 of the present invention, according to a feasible implementation method. The zoom lens in Table 1 corresponds to... Figure 1 and Figure 2 The zoom lens shown.

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

[0099]

[0100] The surface number is assigned according to the order of the surfaces of each lens. For example, surface number 1 represents the object side of the first lens 101, surface number 2 represents the image side of the first lens 101, and so on. The radius of curvature represents the curvature of the lens surface. A positive value means that the surface bends towards the image plane, and a negative value means that the surface bends towards the object plane. Inf represents an infinite radius of curvature. The thickness represents the central axial distance between the current surface and the next surface. The units of the radius of curvature and the thickness are millimeters (mm). The material (Nd) is the refractive index, which represents the ability of the material between the current surface and the next surface to deflect light. A space indicates that the current position is air and the refractive index is 1. The material (Vd) is the dispersion coefficient, which represents the dispersion characteristics of the material between the current surface and the next surface. A space indicates that the current position is air. STO represents the aperture stop. CG represents flat glass. IMA represents the image plane of the lens.

[0101] Table 2 represents the zoom interval values ​​in Table 1.

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

[0103]

[0104] In this embodiment, the aspherical conic coefficient of the aspherical lens in the zoom lens can be defined by the following aspherical formula, but is not limited to the following representation:

[0105]

[0106] Where Z is the axial distance from the vertex of the surface at a position perpendicular to the optical axis and at a height r along the optical axis; c represents the curvature at the vertex of the aspherical surface; a4, a6, a8, a 10 a 12 a 14 a 16 a 18 a 20 For the higher-order aspheric coefficients corresponding to the fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, eighteenth, and twentieth orders of aspheric surfaces, a i r i The combination forms the higher-order terms of the corresponding aspherical surface; K is the conic coefficient.

[0107] For example, Table 3 details the aspherical coefficients of each lens in this embodiment one by way of a feasible implementation.

[0108] Table 3 Design values ​​of aspherical coefficients for various lenses in zoom lenses

[0109]

[0110] Where 7.078894621069E-04 indicates that the coefficient B of face number 6 is 7.078894621069 * 10 -4 And so on.

[0111] The zoom lens provided in this embodiment achieves the following technical specifications:

[0112] Table 4 Technical Specifications of Zoom Lenses

[0113]

[0114] Furthermore, Figure 3 This is an axial aberration diagram of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention. The dominant wavelength is 546.074 nm, and the horizontal direction represents the axial offset relative to a specified target surface, in millimeters (mm). Figure 3 It can be seen that the axial aberrations of different wavelengths from 0 to 1.0 normalized aperture are all controlled within a reasonable range, indicating that the axial chromatic aberration of the zoom lens is well controlled at the wide-angle end, meeting the basic requirement of clear imaging at night and achieving the effect of clear imaging across the entire wavelength range.

[0115] Figure 4 The ray fan pattern of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention is as follows: Figure 4 As shown. The ray fan plot is one of the commonly used evaluation methods by optical designers. In a single plot, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should completely coincide with the horizontal axis, at which point all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The ray fan plot can not only reflect monochromatic aberrations at different wavelengths but also the magnitude of transverse chromatic aberration. Figure 4 It can be seen that this zoom lens closely approximates the horizontal axis at all wavelengths across all fields of view, indicating that its transverse aberrations at all wavelengths are well corrected. In addition, the curves for each color do not show significant dispersion, indicating that this zoom lens also has good correction for chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0116] Figure 5 This is the transverse chromatic aberration curve at the wide-angle end of the zoom lens provided in Embodiment 1 of the present invention. The vertical direction represents the normalized field of view, 0 indicates it is on the optical axis, and the vertex in the transverse direction represents the maximum field of view; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 5 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the wide-angle end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0117] Figure 6 This is an axial aberration diagram of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention. The dominant wavelength is 546.074 nm, and the horizontal direction represents the axial offset relative to a specified target surface, in millimeters (mm). Figure 6 It can be seen that the axial aberrations of the normalized apertures of different wavelengths from 0 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of the zoom lens is well controlled at the telephoto end, meeting the basic requirement of clear imaging at night and achieving the effect of clear imaging across the entire wavelength range.

[0118] Figure 7 The ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention is as follows: Figure 7 As shown. The ray fan plot is one of the commonly used evaluation methods by optical designers. In a single plot, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should completely coincide with the horizontal axis, at which point all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The ray fan plot can not only reflect monochromatic aberrations at different wavelengths but also the magnitude of transverse chromatic aberration. Figure 7 It can be seen that this zoom lens closely approximates the horizontal axis at all wavelengths across all fields of view, indicating that its transverse aberrations at all wavelengths are well corrected. In addition, the curves for each color do not show significant dispersion, indicating that this zoom lens also has good correction for chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0119] Figure 8 The vertical chromatic aberration curve of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention is shown. The vertical direction represents the normalized field of view, 0 indicates on the optical axis, and the vertex in the vertical direction represents the maximum field of view. The dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 8 It can be seen that the transverse chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the telephoto end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0120] Example 2

[0121] Figure 9 This is a schematic diagram of the structure of a zoom lens at the wide-angle end according to Embodiment 2 of the present invention. Figure 10 This is a schematic diagram of the structure of a zoom lens at the telephoto end according to Embodiment 2 of the present invention, as shown below. Figure 9 and Figure 10As shown, the zoom lens includes a first fixed lens group G1, a zoom lens group G2, a focusing lens group G3, and a second fixed lens group G4 arranged sequentially along the optical axis from the object plane to the image plane. The first fixed lens group G1 has positive optical power, the zoom lens group G2 has negative optical power, the focusing lens group G3 has negative optical power, and the second fixed lens group G4 has positive optical power. The first fixed lens group G1 includes a first lens 201 and a second lens 202 arranged sequentially along the optical axis from the object plane to the image plane. The first lens 201 has negative optical power, and the second lens 202 has positive optical power. The zoom lens group G2 includes a third lens 203 and a fourth lens 204 arranged sequentially along the optical axis from the object plane to the image plane. Lens 1204 and fifth lens 205, third lens 203 has negative optical power, fourth lens 204 has negative optical power, and fifth lens 205 has positive optical power; focusing lenses include sixth lens 206, seventh lens 207, eighth lens 208, ninth lens 209 and tenth lens 210 arranged sequentially along the optical axis from the object plane to the image plane, sixth lens 206 has positive optical power, seventh lens 207 has negative optical power, eighth lens 208 has positive optical power, ninth lens 209 has negative optical power and tenth lens 210 has positive optical power; the second fixed lens group G4 includes eleventh lens 211, 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; 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 a first cemented lens group; the seventh lens 207, the eighth lens 208, and the ninth lens 209 form a second cemented lens group. The aperture 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 of the eleventh lens 211.

[0122] Table 5 details the specific optical physical parameters of each lens in the zoom lens provided in Embodiment 2 of the present invention, using a feasible implementation method. The zoom lens in Table 5 corresponds to... Figure 9 and Figure 10 The zoom lens shown.

[0123] Table 5 Design values ​​of optical physical parameters for zoom lenses

[0124]

[0125] The surface number is assigned according to the order of the surfaces of each lens. For example, surface number 1 represents the object side of the first lens 201, surface number 2 represents the image side of the first lens 201, and so on. The radius of curvature represents the curvature of the lens surface. A positive value means that the surface bends towards the image plane, and a negative value means that the surface bends towards the object plane. Inf represents an infinite radius of curvature. The thickness represents the central axial distance between the current surface and the next surface. The units of the radius of curvature and the thickness are millimeters (mm). The material (Nd) is the refractive index, which represents the ability of the material between the current surface and the next surface to deflect light. A space indicates that the current position is air and the refractive index is 1. The material (Vd) is the dispersion coefficient, which represents the dispersion characteristics of the material between the current surface and the next surface. A space indicates that the current position is air. STO represents the aperture stop. CG represents flat glass. IMA represents the image plane of the lens.

[0126] Table 6 represents the zoom interval values ​​from Table 5.

[0127] Table 6 Design values ​​for zoom interval at the wide-angle and telephoto ends of zoom lenses

[0128]

[0129] In this embodiment, the aspherical conic coefficient of the aspherical lens in the zoom lens can be defined by the following aspherical formula, but is not limited to the following representation:

[0130]

[0131] Where Z is the axial distance from the vertex of the surface at a position perpendicular to the optical axis and at a height r along the optical axis; c represents the curvature at the vertex of the aspherical surface; a4, a6, a8, a 10 a 12 a 14 a 16 a 18 a 20 For the higher-order aspheric coefficients corresponding to the fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, eighteenth, and twentieth orders of aspheric surfaces, a i r i The combination forms the higher-order terms of the corresponding aspherical surface; K is the conic coefficient.

[0132] For example, Table 7 details the aspherical coefficients of each lens in this second embodiment with a feasible implementation.

[0133] Table 7 Design values ​​of aspherical coefficients for various lenses in zoom lenses

[0134] Where 8.411731653473E-04 indicates that the coefficient B of face number 6 is 8.411731653473 * 10 -4 And so on.

[0135] The zoom lens provided in this embodiment two achieves the following technical specifications:

[0136] Table 8 Technical Specifications of Zoom Lenses

[0137]

[0138] Furthermore, Figure 11 This is an axial aberration diagram of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention. The dominant wavelength is 546.074 nm, and the horizontal direction represents the axial offset relative to a specified target surface, in millimeters (mm). Figure 11 It can be seen that the axial aberrations of different wavelengths from 0 to 1.0 normalized aperture are all controlled within a reasonable range, indicating that the axial chromatic aberration of the zoom lens is well controlled at the wide-angle end, meeting the basic requirement of clear imaging at night and achieving the effect of clear imaging across the entire wavelength range.

[0139] Figure 12 The ray fan pattern of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention is as follows: Figure 12 As shown. The ray fan plot is one of the commonly used evaluation methods by optical designers. In a single plot, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should completely coincide with the horizontal axis, at which point all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The ray fan plot can not only reflect monochromatic aberrations at different wavelengths but also the magnitude of transverse chromatic aberration. Figure 12 It can be seen that this zoom lens closely approximates the horizontal axis at all wavelengths across all fields of view, indicating that its transverse aberrations at all wavelengths are well corrected. In addition, the curves for each color do not show significant dispersion, indicating that this zoom lens also has good correction for chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0140] Figure 13 This is the transverse chromatic aberration curve at the wide-angle end of the zoom lens provided in Embodiment 2 of the present invention. The vertical direction represents the normalized field of view, 0 indicates that it is on the optical axis, and the vertex in the transverse direction represents the maximum field of view; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 13 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the wide-angle end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0141] Figure 14 This is an axial aberration diagram of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention. The dominant wavelength is 546.074 nm, and the horizontal direction represents the axial offset relative to a specified target surface, in millimeters (mm). Figure 14 It can be seen that the axial aberrations of the normalized apertures of different wavelengths from 0 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of the zoom lens is well controlled at the telephoto end, meeting the basic requirement of clear imaging at night and achieving the effect of clear imaging across the entire wavelength range.

[0142] Figure 15 The ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention is as follows: Figure 15 As shown. The ray fan plot is one of the commonly used evaluation methods by optical designers. In a single plot, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should completely coincide with the horizontal axis, at which point all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The ray fan plot can not only reflect monochromatic aberrations at different wavelengths but also the magnitude of transverse chromatic aberration. Figure 15 It can be seen that this zoom lens closely approximates the horizontal axis at all wavelengths across all fields of view, indicating that its transverse aberrations at all wavelengths are well corrected. In addition, the curves for each color do not show significant dispersion, indicating that this zoom lens also has good correction for chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0143] Figure 16 This is the transverse chromatic aberration curve at the telephoto end of the zoom lens provided in Embodiment 2 of the present invention. The vertical direction represents the normalized field of view, 0 indicates on the optical axis, and the vertex in the transverse direction represents the maximum field of view; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 16 It can be seen that the transverse chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the telephoto end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0144] Example 3

[0145] Figure 17 This is a schematic diagram of the structure of a zoom lens at the wide-angle end according to Embodiment 3 of the present invention. Figure 18 This is a schematic diagram of the structure of a zoom lens at the telephoto end according to Embodiment 3 of the present invention, as shown below. Figure 17 and Figure 18As shown, the zoom lens includes a first fixed lens group G1, a zoom lens group G2, a focusing lens group G3, and a second fixed lens group G4 arranged sequentially along the optical axis from the object plane to the image plane. The first fixed lens group G1 has positive optical power, the zoom lens group G2 has negative optical power, the focusing lens group G3 has negative optical power, and the second fixed lens group G4 has positive optical power. The first fixed lens group G1 includes a first lens 301 and a second lens 302 arranged sequentially along the optical axis from the object plane to the image plane, where the first lens 301 has negative optical power and the second lens 302 has positive optical power. The zoom lens group G2 includes a third lens 303 and a fourth lens 304 arranged sequentially along the optical axis from the object plane to the image plane. Lens 304 and fifth lens 305, third lens 303 has negative optical power, fourth lens 304 has negative optical power, and fifth lens 305 has positive optical power; focusing lenses include sixth lens 306, seventh lens 307, eighth lens 308, ninth lens 309 and tenth lens 310 arranged sequentially along the optical axis from the object plane to the image plane, sixth lens 306 has positive optical power, seventh lens 307 has negative optical power, eighth lens 308 has positive optical power, ninth lens 309 has negative optical power and tenth lens 310 has positive optical power; the second fixed lens group G4 includes eleventh lens 311, eleventh lens 311 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 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; 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 a first cemented lens group; the seventh lens 307, the eighth lens 108, and the ninth lens 309 form a second cemented lens group. The aperture 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 of the eleventh lens 311.

[0146] Table 9 details the specific optical physical parameters of each lens in the zoom lens provided in Embodiment 3 of the present invention, according to a feasible implementation method. The zoom lens in Table 9 corresponds to... Figure 17 and Figure 18 The zoom lens shown.

[0147] Table 9 Design values ​​of optical physical parameters for zoom lenses

[0148] The surface number is assigned according to the order of the surfaces of each lens. For example, surface number 1 represents the object side of the first lens 301, surface number 2 represents the image side of the first lens 301, and so on. The radius of curvature represents the curvature of the lens surface. A positive value means that the surface bends towards the image plane, and a negative value means that the surface bends towards the object plane. Inf represents an infinite radius of curvature. The thickness represents the central axial distance between the current surface and the next surface. The units of the radius of curvature and the thickness are millimeters (mm). The material (Nd) is the refractive index, which represents the ability of the material between the current surface and the next surface to deflect light. A space indicates that the current position is air and the refractive index is 1. The material (Vd) is the dispersion coefficient, which represents the dispersion characteristics of the material between the current surface and the next surface. A space indicates that the current position is air. STO represents the aperture stop. CG represents flat glass. IMA represents the image plane of the lens.

[0149] Table 10 shows the zoom interval values ​​in Table 9.

[0150] Table 9 Design values ​​for zoom interval at the wide-angle and telephoto ends of zoom lenses

[0151]

[0152] In this embodiment, the aspherical conic coefficient of the aspherical lens in the zoom lens can be defined by the following aspherical formula, but is not limited to the following representation:

[0153] Where Z is the axial distance from the vertex of the surface at a position perpendicular to the optical axis at a height r; c represents the curvature at the vertex of the aspherical surface; a4, a6, a8, a 10 a 12 a 14 a 16 a 18 a 20 For the higher-order aspheric coefficients corresponding to the fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, eighteenth, and twentieth orders of aspheric surfaces, a i r i The terms are combined to form higher-order terms for the corresponding aspherical surfaces; K is the conic coefficient.

[0154] For example, Table 11 details the aspherical coefficients of each lens in this embodiment three according to a feasible implementation.

[0155] Table 11 Design values ​​of aspherical coefficients for various lenses in zoom lenses

[0156] Where 8.584573774925E-05 indicates that the coefficient B of face number 6 is 8.584573774925 * 10 -5 And so on.

[0157] The zoom lens provided in this embodiment three achieves the following technical specifications:

[0158] Table 12 Technical Specifications of Zoom Lenses

[0159]

[0160] Furthermore, Figure 19 This is an axial aberration diagram of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention. The dominant wavelength is 546.074 nm, and the horizontal direction represents the axial offset relative to a specified target surface, in millimeters (mm). Figure 19 It can be seen that the axial aberrations of different wavelengths from 0 to 1.0 normalized aperture are all controlled within a reasonable range, indicating that the axial chromatic aberration of the zoom lens is well controlled at the wide-angle end, meeting the basic requirement of clear imaging at night and achieving the effect of clear imaging across the entire wavelength range.

[0161] Figure 20 The ray fan pattern of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention is as follows: Figure 20 As shown. The ray fan plot is one of the commonly used evaluation methods by optical designers. In a single plot, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should completely coincide with the horizontal axis, at which point all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The ray fan plot can not only reflect monochromatic aberrations at different wavelengths but also the magnitude of transverse chromatic aberration. Figure 20 It can be seen that this zoom lens closely approximates the horizontal axis at all wavelengths across all fields of view, indicating that its transverse aberrations at all wavelengths are well corrected. In addition, the curves for each color do not show significant dispersion, indicating that this zoom lens also has good correction for chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0162] Figure 21 This is the transverse chromatic aberration curve at the wide-angle end of the zoom lens provided in Embodiment 3 of the present invention. The vertical direction represents the normalized field of view, 0 indicates that it is on the optical axis, and the vertex in the transverse direction represents the maximum field of view; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 21 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the wide-angle end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0163] Figure 22 This is an axial aberration diagram of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention. The dominant wavelength is 546.074 nm, and the horizontal direction represents the axial offset relative to a specified target surface, in millimeters (mm). Figure 22 It can be seen that the axial aberrations of the normalized apertures of different wavelengths from 0 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of the zoom lens is well controlled at the telephoto end, meeting the basic requirement of clear imaging at night and achieving the effect of clear imaging across the entire wavelength range.

[0164] Figure 23 The ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention is as follows: Figure 23 As shown. The ray fan plot is one of the commonly used evaluation methods by optical designers. In a single plot, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should completely coincide with the horizontal axis, at which point all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The ray fan plot can not only reflect monochromatic aberrations at different wavelengths but also the magnitude of transverse chromatic aberration. Figure 23 It can be seen that this zoom lens closely approximates the horizontal axis at all wavelengths across all fields of view, indicating that its transverse aberrations at all wavelengths are well corrected. In addition, the curves for each color do not show significant dispersion, indicating that this zoom lens also has good correction for chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0165] Figure 24 This is the transverse chromatic aberration curve at the telephoto end of the zoom lens provided in Embodiment 3 of the present invention. The vertical direction represents the normalized field of view, 0 indicates on the optical axis, and the vertex in the transverse direction represents the maximum field of view; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 24 It can be seen that the transverse chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the telephoto end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0166] To provide a clearer explanation of the above embodiments, Table 13 details the specific optical physical parameters of each lens in the zoom lens provided in Embodiments 1 to 3 of the present invention.

[0167] Table 13 Design values ​​of optical physical parameters for zoom lenses

[0168]

[0169] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

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

2. The zoom lens according to claim 1, characterized in that, 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 focusing 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, characterized in that, 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 zoom lens group has a focal length of F45 for the first cemented lens group and an focal length of F789 for the second cemented lens group in the focusing lens group; the zoom lens has a focal length of FW at the wide-angle end. -20.50≤F45 / FW≤-19.00; -17.50≤F789 / FW≤-7.

00.

4. The zoom lens according to claim 1, characterized in that, The first lens has a refractive index of Nd1 and an Abbe number of Vd1; the fourth lens has a refractive index of Nd4 and an Abbe number of Vd4; the fifth lens has a refractive index of Nd5 and an Abbe number of Vd5; the eighth lens has a refractive index of Nd8 and an Abbe number of Vd8; and the eleventh lens has a refractive index of Nd11 and an Abbe number of 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.

5. The zoom lens according to claim 1, characterized in that, The zoom lens has a focal length of FW at the wide-angle end and an entrance pupil diameter of EPDW at the wide-angle end; wherein, 1.43≤FW / EPDW≤1.

50.

6. The zoom lens according to claim 1, characterized in that, At least one plastic aspherical lens is provided in the zoom lens group and the focusing lens group; The eleventh lens is a plastic aspherical lens.

7. The zoom lens according to claim 1, characterized in that, The zoom lens also includes an aperture stop, which is located between the zoom lens group and the focusing lens group.

8. A lens module, characterized in that, The lens module includes an image sensor chip and a zoom lens as described in any one of claims 1 to 7, wherein the image sensor chip is disposed on the image plane side of the zoom lens; The diagonal length of the photosensitive chip is H, the tangent of the incident angle at the wide-angle end of the zoom lens is TAN(θW), and the tangent of the incident angle at the telephoto end of the zoom lens is TAN(θT); wherein, 2.95≤H / TAN(θW) ≤3.50; 18.00≤H / TAN(θT) ≤22.00.

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