Zoom lens

Abstract

The zoom lens comprises a focusing lens group, a zoom lens group and a fixed lens group which are sequentially arranged from an object plane to an image plane along an optical axis, the focusing lens group and the zoom lens group are movably arranged along the optical axis direction; the focusing lens group has negative focal power, the zoom lens group has positive focal power, and the fixed lens group has negative focal power; the focusing lens group comprises a first lens, a second lens, a third lens and a fourth lens with negative focal power, negative focal power, negative focal power and positive focal power in sequence; the zoom lens group comprises a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens with positive focal power, positive focal power, negative focal power, positive focal power and negative focal power in sequence; and the fixed lens group comprises a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens and a fourteenth lens of which the focal powers are negative, positive, positive, negative, positive or negative in sequence. The zoom lens has the advantages of large aperture, high image quality and the like, and can adapt to a large-target-surface chip.

Description

Technical Field

[0001] This invention relates to the field of lens technology, and more particularly to a zoom lens. Background Technology

[0002] In the security field, zoom lenses are widely used due to their advantages such as long shooting distance and wide shooting angle. With technological advancements, cameras are gradually becoming smaller and more refined, which places even stricter demands on mainstream zoom lenses.

[0003] Currently, 1 / 1.2” sensors are becoming increasingly common, but traditional zoom lenses typically use 1 / 2.7” sensors. Traditional zoom lenses using 1 / 1.2” sensors suffer from issues such as small aperture and lack of infrared confocal focus. Therefore, it is essential to develop a high-quality zoom lens that is compact, has a large aperture, and features infrared high and low temperature confocal focus, and can be used with a 1 / 1.2” sensor. Summary of the Invention

[0004] This invention provides a zoom lens that has advantages such as large aperture and high image quality, and can be adapted to large-area chips.

[0005] The zoom lens provided by the present invention includes a focusing lens group, a zoom lens group and a fixed lens group arranged sequentially along the optical axis from the object plane to the image plane; the focusing lens group and the zoom lens group are movable along the optical axis.

[0006] The focusing lens group has negative optical power, the zoom lens group has positive optical power, and the fixed lens group has negative optical power.

[0007] The focusing lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the first lens is negative, the optical power of the second lens is negative, the optical power of the third lens is negative, and the optical power of the fourth lens is positive.

[0008] The zoom lens group includes a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the fifth lens is positive, the optical power of the sixth lens is positive, the optical power of the seventh lens is negative, the optical power of the eighth lens is positive, and the optical power of the ninth lens is negative.

[0009] The fixed lens group includes the tenth, eleventh, twelfth, thirteenth, and fourteenth lenses arranged sequentially from the object plane to the image plane. The optical power of the tenth lens is negative, the optical power of the eleventh lens is positive, the optical power of the twelfth lens is positive, the optical power of the thirteenth lens is negative, and the optical power of the fourteenth lens is either positive or negative.

[0010] Optionally, the surface of the lens adjacent to the object plane is the object-side surface, and the surface of the lens adjacent to the image plane is the image-side surface;

[0011] In the focusing lens group, the first lens is a convex-concave lens, the second lens is a convex-concave lens, the third lens is a biconcave lens, and the object-side surface of the fourth lens convexes towards the object surface.

[0012] In the zoom lens group, the object-side surface of the fifth lens convexes towards the object plane, the sixth lens is a biconvex lens, the seventh lens is a convex-concave lens, the eighth lens is a biconvex lens, and the ninth lens is a concave-convex lens.

[0013] In the fixed lens group, the tenth lens is a biconcave lens, the object-side surface of the eleventh lens is convex towards the object plane, the twelfth lens is a biconvex lens, the thirteenth lens is a meniscus lens, and the paraxial region of the image-side surface of the fourteenth lens is concave towards the image plane.

[0014] Optionally, in the focusing lens group, the third lens is a glass aspherical lens, and the remaining lenses are glass spherical lenses;

[0015] In the zoom lens group, the fifth lens is a glass aspherical lens, and the remaining lenses are glass spherical lenses;

[0016] In the fixed lens group, the fourteenth lens is a glass aspherical lens, and the remaining lenses are glass spherical lenses.

[0017] Optionally, the first lens has a refractive index of nd1 and an Abbe number of vd1; the fifth lens has a refractive index of nd5 and an Abbe number of vd5; the sixth lens has a refractive index of nd6 and an Abbe number of vd6; the thirteenth lens has a refractive index of nd13 and an Abbe number of vd13; and the fourteenth lens has a refractive index of nd14 and an Abbe number of vd14; wherein:

[0018] 1.43≤nd1≤1.50; 70.47≤vd1≤95.25;

[0019] 1.53≤nd5≤1.60; 55.47≤vd5≤71.69;

[0020] 1.43≤nd6≤1.50; 81.50≤vd6≤95.10;

[0021] 1.75≤nd13≤1.93; 20.10≤vd13≤52.40

[0022] 1.75≤nd14≤1.86;40.00≤vd14≤52.40;

[0023] Optionally, the focal length of the focusing lens group is F1, the focal length of the zoom lens group is F2, the focal length of the fixed lens group is F3, and the focal length of the zoom lens at the telephoto end is FT, where:

[0024] -0.77≤F1 / FT≤-0.76;

[0025] 0.85≤F2 / FT≤1.04;

[0026] -21.6≤F3 / FT≤-9.5.

[0027] Optionally, the movable range of the focusing lens group is S1, the total length of the zoom lens at the wide-angle end is TTLW, and the maximum lens diameter in the focusing lens group is ΦG1, where:

[0028] 0.1≤S1 / TTLW≤0.11;

[0029] 0.42 < ΦG1 / TTLW < 0.451.

[0030] Optionally, in the zoom lens group, the seventh, eighth, and ninth lenses form a first cemented lens. The focal length of the first cemented lens is EFL1, the focal length of the zoom lens group is F2, the refractive index of the eighth lens is nd8, and the Abbe number is vd8, wherein:

[0031] 1.43≤nd8≤1.50;81.60≤vd8≤95.24;

[0032] -2.15≤EFL1 / F2≤-0.92.

[0033] Optionally, in the fixed lens group, the tenth and eleventh lenses form a second cemented lens with a focal length of EFL2. The focal length of the zoom lens at the telephoto end is FT. The diameter of the fourteenth lens is Φ14, and the axial distance between the edge and center of the fourteenth lens at its maximum thickness is S14, wherein:

[0034] -2.11≤EFL2 / FT≤-1;

[0035] 0.075≤S14 / Φ14≤0.18.

[0036] Optionally, the focal length of the zoom lens at the telephoto end is FT, and the focal length of the zoom lens at the wide-angle end is FW, where:

[0037] FT / FW ≥ 2.20.

[0038] Optionally, the zoom lens also includes an aperture stop located in the optical path between the focusing lens group and the zoom lens group.

[0039] The technical solution of this invention provides a three-element zoom lens composed of 14 lenses. Specifically, it includes a focusing lens group, a zoom lens group, and a fixed lens group arranged sequentially along the optical axis from the object plane to the image plane. By reasonably matching the optical power of each lens group and each lens, aberrations can be better corrected, ensuring image clarity at different focal lengths. At the same time, this zoom lens has the advantage of a large aperture, which can be adapted to large target surface chips (1 / 1.2”) to meet the needs of security applications.

[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 zoom lens at the wide-angle end provided in Embodiment 1 of the present invention;

[0043] Figure 2 This is a schematic diagram of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention;

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

[0045] Figure 4 This is the axial aberration curve of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention;

[0046] Figure 5 This is the ray fan diagram of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention;

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

[0048] Figure 7 This is the transverse chromatic aberration diagram of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention;

[0049] Figure 8 This is the transverse chromatic aberration diagram of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention;

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

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

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

[0053] Figure 12 This is the axial aberration curve of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention;

[0054] Figure 13 This is the ray fan pattern of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention;

[0055] Figure 14 This is the ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention;

[0056] Figure 15 This is the transverse chromatic aberration diagram of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention;

[0057] Figure 16 This is the transverse chromatic aberration diagram 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 zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

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

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

[0061] Figure 20 This is the axial aberration curve of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention;

[0062] Figure 21 This is the ray fan pattern of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

[0063] Figure 22 This is the ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention;

[0064] Figure 23 This is the transverse chromatic aberration diagram of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

[0065] Figure 24This is the vertical chromatic aberration diagram 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] Various modifications and variations can be made to this application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, this application is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided in this application can be combined with each other without contradiction.

[0068] First, it should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "comprising" and similar terms mean that the element or object preceding the word encompasses the element or object listed after the word and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described object changes. Furthermore, the shapes and sizes of the components in the accompanying drawings do not reflect actual proportions and are only intended to illustrate the content of this invention.

[0069] Figure 1 This is a schematic diagram of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention, as shown below. Figure 1 and Figure 2As shown, the zoom lens provided by the present invention includes a focusing lens group G1, a zoom lens group G2, and a fixed lens group G3 arranged sequentially along the optical axis from the object plane to the image plane; the focusing lens group G1 and the zoom lens group G2 are movable along the optical axis; the focusing lens group G1 has negative optical power, the zoom lens group G2 has positive optical power, and the fixed lens group G3 has negative optical power; the focusing lens group G1 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged sequentially along the optical axis from the object plane to the image plane; the first lens L1 has negative optical power, the second lens L2 has negative optical power, the third lens L3 has negative optical power, and the fourth lens L4 has positive optical power; the zoom lens group G2 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged sequentially along the optical axis from the object plane to the image plane. The fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8, and ninth lens L9 are arranged in a specific order. The optical power of the fifth lens L5 is positive, the optical power of the sixth lens L6 is positive, the optical power of the seventh lens L7 is negative, the optical power of the eighth lens L8 is positive, and the optical power of the ninth lens L9 is negative. The fixed lens group G3 includes a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, and a fourteenth lens L14, arranged sequentially from the object plane to the image plane. The optical power of the tenth lens L10 is negative, the optical power of the eleventh lens L11 is positive, the optical power of the twelfth lens L12 is positive, the optical power of the thirteenth lens L13 is negative, and the optical power of the fourteenth lens L14 is positive. In other embodiments, the optical power of the fourteenth lens L14 may also be negative.

[0070] In the zoom lens provided in this embodiment, the focusing lens group G1, the zoom lens group G2, and the fixed lens group G3 can be arranged in one lens barrel. Figure 1 (Not shown in the image). The focusing lens group G1 and the zoom lens group G2 can reciprocate along the optical axis within the lens barrel, while the fixed lens group G3 is fixed in position within the lens. Through the combined movement of the focusing lens group G1 and the zoom lens group G2, 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.

[0071] Understandably, during the zoom process achieved by moving the focusing lens group G1 and the zoom lens group G2, the zoom lens is at its shortest focal length, i.e., at the wide-angle end, and at its longest focal length, i.e., 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.

[0072] 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).

[0073] In this embodiment, by setting the focusing lens group G1 to have negative optical power, the zoom lens group G2 to have positive optical power, and the fixed lens group G3 to have negative optical power, the optical powers of the focusing lens group G1, the zoom lens group G2, and the fixed lens group G3 are coordinated to compensate for the aberrations caused by the zoom movement of the focusing lens group G1 and the zoom lens group G2, thus ensuring the clarity of the image under different focal lengths.

[0074] Reference Figure 1 Optionally, the zoom lens also includes an aperture stop 130, located in the optical path between the focusing lens group G1 and the zoom lens group G2. By properly positioning the aperture stop 130, coma generated by the system can be significantly reduced. Furthermore, by setting the focusing lens group G1 to have a negative optical power, a larger aperture can be ensured before light enters the aperture stop, thus increasing the lens's aperture.

[0075] Further, such as Figure 1 and Figure 2 As shown, the focusing lens group G1 includes a first lens L1 with negative optical power, a second lens L2 with negative optical power, a third lens L3 with negative optical power, and a fourth lens L4 with positive optical power. By rationally matching the optical powers of each lens in the focusing lens group G1, the optical power distribution in G1 is reasonable, preventing significant light refraction and minimizing ghosting and other problems that occur during zoom lens use. Specifically, setting the fourth lens L4 to have positive optical power slightly reduces the angle of light entering the aperture stop, effectively preventing stray light reflections or difficult-to-handle advanced aberrations at the aperture stop, ensuring the theoretical aberration balance and actual performance of the lens.

[0076] like Figure 1 and Figure 2 As shown, the zoom lens group G2 includes a fifth lens L5 with positive optical power, a sixth lens L6 with positive optical power, a seventh lens L7 with negative optical power, an eighth lens L8 with positive optical power, and a ninth lens L9 with negative optical power. By reasonably matching the optical powers of each lens in the zoom lens group G2, the aberration changes of the zoom lens group G2 are small during use, thus ensuring the optical performance of the lens.

[0077] like Figure 1 and Figure 2 As shown, the fixed lens group G3 includes a tenth lens L10 with negative optical power, an eleventh lens L11 with positive optical power, a twelfth lens L12 with positive optical power, a thirteenth lens L13 with negative optical power, and a fourteenth lens L14 with either positive or negative optical power. By reasonably matching the optical powers of each lens in the fixed lens group G3, aberrations in various states during the zoom process of the zoom lens can be corrected, ensuring that the lens forms a clear image across the entire focal length and meeting the usage requirements under different conditions.

[0078] In summary, this invention provides a three-element zoom lens composed of 14 lenses, specifically including a focusing lens group G1, a zoom lens group G2, and a fixed lens group G3 arranged sequentially along the optical axis from the object plane to the image plane. By reasonably matching the lens groups and the optical power of each lens, aberrations can be effectively corrected, ensuring image clarity at different focal lengths. At the same time, this zoom lens has the advantage of a large aperture, making it compatible with large-area chips (1 / 1.2”) and meeting the needs of a wide range of security applications.

[0079] Based on the above embodiments, such as Figure 1 and Figure 2 As shown, optionally, the surface of the lens adjacent to the object plane is the object-side surface, and the surface of the lens adjacent to the image plane is the image-side surface; in the focusing lens group G1, the first lens L1 is a convex-concave lens, the second lens L2 is a convex-concave lens, the third lens L3 is a biconcave lens, and the object-side surface of the fourth lens L4 convexes towards the object plane; in the zoom lens group G2, the object-side surface of the fifth lens L5 convexes towards the object plane, the sixth lens L6 is a biconvex lens, the seventh lens L7 is a convex-concave lens, the eighth lens L8 is a biconvex lens, and the ninth lens L9 is a concave-convex lens; in the fixed lens group G3, the tenth lens L10 is a biconcave lens, the object-side surface of the eleventh lens L11 convexes towards the object plane, the twelfth lens L12 is a biconvex lens, the thirteenth lens L13 is a meniscus lens, and the paraxial region of the image-side surface of the fourteenth lens L14 is concave towards the image plane.

[0080] Among them, the first lens L1 is a convex-concave lens, specifically meaning that the object-side surface of the first lens L1 is convex towards the object plane, and the image-side surface of the first lens L1 is convex-concave towards the image plane. The surface shapes of other lenses are similar and will not be described in detail.

[0081] Specifically, the paraxial region of the image-side surface of the fourteenth lens L14, that is, the region of the image-side surface closest to the optical axis, has its image-side surface concave towards the image plane. The off-axis region of the image-side surface of the fourteenth lens L14 can be concave or convex towards the image plane, as will be illustrated in subsequent examples.

[0082] It should be noted that, provided that the fourth lens L4 has positive optical power, the embodiment of the present invention does not limit the shape of the image-side surface of the fourth lens L4, and specific examples will be provided later. Similarly, provided that the fifth lens L5 has positive optical power, the embodiment of the present invention does not limit the shape of the image-side surface of the fifth lens L5; provided that the eleventh lens L11 has positive optical power, the embodiment of the present invention does not limit the shape of the image-side surface of the eleventh lens L11; provided that the thirteenth lens L13 has negative optical power, the thirteenth lens L13 is meniscus-shaped, and can be bent towards the image plane or towards the object plane, and the embodiment of the present invention does not limit this.

[0083] This embodiment ensures that the optical power of each lens meets the requirements of the above embodiment by reasonably setting the surface shape of each lens, while also ensuring that the entire zoom lens structure is compact and the zoom lens has a high degree of integration.

[0084] Optionally, at least one glass aspherical lens is present in each of the focusing lens group G1, the zoom lens group G2, and the fixed lens group G3.

[0085] like Figure 1 and Figure 2 As shown, optionally, in the focusing lens group G1, the third lens L3 is a glass aspherical lens, and the remaining lenses are glass spherical lenses; in the zoom lens group G2, the fifth lens L5 is a glass aspherical lens, and the remaining lenses are glass spherical lenses; in the fixed lens group G3, the fourteenth lens L14 is a glass aspherical lens, and the remaining lenses are glass spherical lenses.

[0086] In zoom lenses, ensuring image quality is fundamentally based on maintaining good aberration correction throughout the zoom process. The most effective method is to correct the aberrations of each lens group within the zoom lens separately. Aspherical lenses are particularly effective at correcting higher-order aberrations. In this invention, the third lens L3 in the focusing lens group G1, the fifth lens L5 in the zoom lens group G2, and the fourteenth lens L14 in the fixed lens group G3 are all made of glass aspherical lenses. This allows them to work effectively with other lenses in each lens group to correct aberrations in the zoom lens, achieving aberration balance.

[0087] The glass spherical lens and the glass aspherical lens can be made of various types of glass known to those skilled in the art, and the embodiments of the present invention will not elaborate on or limit them.

[0088] like Figure 1 and Figure 2As shown, optionally, in the zoom lens group G2, the seventh lens L7, the eighth lens L8 and the ninth lens L9 form the first cemented lens 110, and in the fixed lens group G3, the tenth lens L10 and the eleventh lens L11 form the second cemented lens 120.

[0089] Cementing lenses effectively reduces air gaps between them, further reducing the overall lens length. Furthermore, this method reduces chromatic aberration by utilizing the complementary chromatic aberration of the positive and negative optical surfaces of the cemented lenses. Simultaneously, it balances chromatic aberration caused by other components in the zoom lens using residual chromatic aberration, allowing for thorough correction of various aberrations and improved imaging performance. This results in increased resolution, optimized distortion and other optical properties within a compact structure, and reduced light loss due to inter-lens reflections, improving illumination and ultimately enhancing image quality and sharpness. Additionally, cementing reduces the number of assembly components, simplifying assembly procedures, lowering costs, and reducing tolerance sensitivity issues such as tilting / eccentricity of lens units during assembly.

[0090] Furthermore, in the focusing lens group G1, the aspherical lens (fifth lens L5) combined with the seventh lens L7, the eighth lens L8, and the ninth lens L9 to form a cemented triplet lens (first cemented lens 110) can reduce the higher aberrations generated after light passes through the aperture. In the fixed lens group G3, the second cemented lens 120 composed of the tenth lens L10 and the eleventh lens L11, combined with the aspherical lens (fourteenth lens L14), can continue to eliminate higher aberrations at the end of the lens, while also expanding the lens target surface (size) to ensure the operating environment and image quality.

[0091] In addition, the above combination method can ensure the lens's stable high and low temperature performance and meet the usage requirements under more complex conditions.

[0092] like Figure 1 and Figure 2 As shown, optionally, the first lens L1 has a refractive index of nd1 and an Abbe number of vd1; the fifth lens L5 has a refractive index of nd5 and an Abbe number of vd5; the sixth lens L6 has a refractive index of nd6 and an Abbe number of vd6; the thirteenth lens L13 has a refractive index of nd13 and an Abbe number of vd13; and the fourteenth lens L14 has a refractive index of nd14 and an Abbe number of vd14; wherein:

[0093] 1.43≤nd1≤1.50; 70.47≤vd1≤95.25;

[0094] 1.53≤nd5≤1.60; 55.47≤vd5≤71.69;

[0095] 1.43≤nd6≤1.50; 81.50≤vd6≤95.10;

[0096] 1.75≤nd13≤1.93; 20.10≤vd13≤52.40

[0097] 1.75≤nd14≤1.86;40.00≤vd14≤52.40;

[0098] 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, and 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 of the medium, the larger the Abbe number.

[0099] Specifically, in the focusing lens group G1, the first lens L1 uses a material with low refractive index and high Abbe number, which can achieve higher transmittance while achieving the same effect. At the same time, it can control the chromatic aberration of the lens from the front end, making the visual effect of the image more natural.

[0100] In the zoom lens group G2, the fifth lens L5 and the sixth lens L6 are the first two lenses encountered by light after passing through the aperture. The fifth lens L5 and the sixth lens L6 are made of high Abbe number material, which can work with the cemented lens at the rear (first cemented lens 110) to eliminate the lens's advanced aberrations to the greatest extent and ensure that the lens can form clear images in the working band and at different temperatures, achieving the effects of infrared confocal and high and low temperature confocal.

[0101] In the fixed lens group G3, the thirteenth lens L13 and the fourteenth lens L14 use high refractive index lenses, which can reduce the overall weight of the lens and also has a certain limiting effect on the light emission angle.

[0102] like Figure 1 and Figure 2 As shown, optionally, the focal length of the focusing lens group G1 is F1, the focal length of the zoom lens group G2 is F2, the focal length of the fixed lens group G3 is F3, and the focal length of the zoom lens at the telephoto end is FT, where: -0.77≤F1 / FT≤-0.76; 0.85≤F2 / FT≤1.04; -21.6≤F3 / FT≤-9.5.

[0103] By adopting the above focal length combination, a reasonable combination of optical power can be achieved, allowing light to pass through the lens more smoothly and greatly correcting the impact of advanced lens aberrations on image quality.

[0104] like Figure 1 and Figure 2As shown, optionally, the movable range of the focusing lens group G1 is S1, the total length of the zoom lens at the wide-angle end is TTLW, and the maximum lens diameter in the focusing lens group G1 is ΦG1, where: 0.1≤S1 / TTLW≤0.11; 0.42<ΦG1 / TTLW<0.451.

[0105] Specifically, the movable range of the focusing lens group G1 can be understood as the distance between the closest and farthest positions of G1 to the image plane during its movement. The total length of the zoom lens at the wide-angle end can be understood as the distance along the optical axis between the object-side surface of the first lens L1 and the image plane when the zoom lens is at the wide-angle end. By controlling the position of the focusing lens group G1, its movable range can be minimized to the greatest extent possible, thereby significantly reducing the lens size.

[0106] The maximum lens diameter in the focusing lens group G1 can be understood as the diameter of the lens with the largest diameter among all lenses in the focusing lens group G1. In this embodiment, the maximum lens diameter specifically refers to the diameter of the first lens L1. By limiting the maximum lens diameter as described above, the lens size can be controlled, making the lens more compact while maximizing the field of view and light intake to meet the usage requirements under different ambient brightness conditions.

[0107] like Figure 1 and Figure 2 As shown, optionally, in the zoom lens group G2, the focal length of the first cemented lens 110 is EFL1, the focal length of the zoom lens group G2 is F2, the refractive index of the eighth lens L8 is nd8, and the Abbe number is vd8, wherein:

[0108] 1.43≤nd8≤1.50;81.60≤vd8≤95.24;-2.15≤EFL1 / F2≤-0.92;

[0109] After light passes through the aperture stop, the use of a cemented lens in the zoom lens group G2 effectively corrects chromatic aberration, preventing the chromatic aberration from accumulating at the rear of the lens and requiring a large amount of high Abbe number material to pull it back, thus saving costs and improving image quality. By setting the focal length between the first cemented lens 110 and the zoom lens group G2 to satisfy the above relationship, the optical power distribution in the entire zoom lens group G2 is ensured to be uniform, improving the lens's image quality.

[0110] In addition, the use of a low-refractive-index, high-Abbe number material in the eighth lens L8 ensures that the first cemented lens 110 will focus the main wavelengths to the same point during use, thereby significantly improving the color fidelity and image sharpness of the lens and increasing the resolution of the lens.

[0111] like Figure 2As shown, optionally, in the fixed lens group G3, the focal length of the second cemented lens 120 is EFL2, the focal length of the zoom lens at the telephoto end is FT, the diameter of the fourteenth lens L14 is Φ14, and the axial distance between the edge and the center of the fourteenth lens L14 at its maximum thickness is S14, wherein:

[0112] -2.11≤EFL2 / FT≤-1;0.075≤S14 / Φ14≤0.18;

[0113] In the fixed lens group G3, by setting the second cemented lens 120 and the focal length of the zoom lens at the telephoto end to satisfy the above relationship, the single-group chromatic aberration of the fixed lens group G3 can be guaranteed, thereby improving the imaging quality of the zoom lens.

[0114] In addition, the lens at the rear of the zoom lens (the fourteenth lens L14) is an aspherical lens. By limiting the range of the ratio between the axial distance between the edge position and the center position of the fourteenth lens L14 at its maximum thickness and the diameter of the fourteenth lens L14, the direction of the edge light can be controlled while ensuring clear center focus. This controls the imaging height of the incident light at the edge of the lens, thus achieving the purpose of matching a large target surface chip.

[0115] Optionally, the focal length of the zoom lens at the telephoto end is FT, and the focal length of the zoom lens at the wide-angle end is FW, where FT / FW ≥ 2.20. By controlling the focal length ratio of the zoom lens at the wide-angle and telephoto ends, the zoom range and focal length range of the lens can be controlled.

[0116] like Figure 1 and Figure 2 As shown, optionally, the zoom lens also includes a flat glass plate 140 located in the optical path between the fourteenth lens L14 and the image plane. The flat glass plate 140 is used to protect the photosensitive chip in the imaging sensor, which converts the light signals collected by the zoom lens into electrical signals, thereby ensuring the imaging effect of the zoom lens.

[0117] Optionally, the surface profiles of the aforementioned aspherical lenses (third lens L3, fifth lens L5, and fourteenth lens L14) satisfy the formula:

[0118]

[0119] Where Z represents the sag of the aspherical surface; r represents the radial coordinate perpendicular to the optical axis; c represents the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature; k represents the conic section constant; and A, B, C, D, E, F, and G represent the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order coefficients of the aspherical polynomial, respectively.

[0120] In summary, the technical solution of this invention uses 14 lenses to form a three-element zoom lens. By reasonably matching the lens groups and the optical power of each lens, and by reasonably setting the surface shape, refractive index, Abbe number and cementation state of each lens, a zoom lens with small volume, large aperture, large target surface, high image quality and infrared high and low temperature confocal is achieved, which can be used with 1 / 1.2" large target surface photosensitive chips.

[0121] For example, 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. The zoom lens in Table 1 corresponds to... Figure 1 and Figure 2 The zoom lens shown.

[0122] Table 1 Design values ​​of optical physical parameters for zoom lenses

[0123]

[0124]

[0125] The surface number is determined by the order of the lenses. For example, surface number "1" represents the object side of the first lens, surface number "2" represents the image side of the first lens, and so on. "STO" represents the aperture stop of the lens. "CG" represents flat glass. The radius of curvature represents the curvature of the lens surface. A positive value means that the surface bends towards the object side with the center closer to the image side, and a negative value means that the surface bends towards the image side with the center closer to the object side. "PL" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the center of the current surface and the next surface. The material (nd) represents the refractive index, which is 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) represents the Abbe number, which is the dispersion characteristic of the material between the current surface and the next surface. A space indicates that the current position is air.

[0126] For example, Table 2 shows the values ​​for the zoom intervals in Table 1.

[0127] Table 2 Design values ​​for the variable pitch at the wide-angle and telephoto ends of zoom lenses.

[0128] Wide-angle end telephoto end Zoom interval 1 6.5569 0.8689 Zoom interval 2 6.9273 0.300 Zoom interval 3 0.4997 7.1270

[0129] For example, Table 3 details the aspherical coefficients of each lens in this embodiment one by way of a feasible implementation.

[0130] Table 3 Design values ​​of aspherical coefficients for various lenses in zoom lenses.

[0131]

[0132]

[0133] Where 5.90645474574237E-05 indicates that the coefficient A of face number "5" is 5.90645474574237 * 10. -5 And so on.

[0134] The zoom lens provided in this embodiment achieves the following technical specifications:

[0135] Table 4 Technical Specifications of Zoom Lenses

[0136]

[0137] Further, Figure 3 This is an axial aberration curve of a zoom lens at the wide-angle end provided in Embodiment 1 of the present invention. Figure 4 This is an axial aberration curve of a zoom lens at the telephoto end provided in Embodiment 1 of the present invention, such as... Figure 3 and Figure 4 As shown, the vertical direction represents the normalized aperture size, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal coordinate values ​​represent the axial offset relative to the specified target surface, in millimeters (mm); from Figure 3 and Figure 4 It can be seen that at both the wide-angle and telephoto ends, the axial aberrations of different wavelengths (0–1.0 normalized aperture) are all controlled within a reasonable range, indicating that the axial aberrations of the zoom lens are well controlled, meeting the basic requirement of clear imaging at night and achieving the effect of clear imaging across the entire wavelength range.

[0138] Figure 5 This is a ray fan pattern of a zoom lens at the wide-angle end, as provided in Embodiment 1 of the present invention. Figure 6 This is a ray fan pattern of a zoom lens at the telephoto end provided in Embodiment 1 of the present invention, such as... Figure 5 and Figure 6 As shown, in a single image, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should perfectly coincide with the horizontal axis, in which case 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 fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 5 and Figure 6 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.

[0139] Figure 7 This is a transverse chromatic aberration diagram of a zoom lens at the wide-angle end, provided in Embodiment 1 of the present invention. Figure 8 This is a transverse chromatic aberration diagram of a zoom lens at the telephoto end provided in Embodiment 1 of the present invention, such as... Figure 7 and Figure 8 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 7 and 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.

[0140] Example 2

[0141] 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 10 As shown, the zoom lens provided by the present invention includes a focusing lens group G1, a zoom lens group G2, and a fixed lens group G3 arranged sequentially along the optical axis from the object plane to the image plane; the focusing lens group G1 and the zoom lens group G2 are movable along the optical axis; the focusing lens group G1 has negative optical power, the zoom lens group G2 has positive optical power, and the fixed lens group G3 has negative optical power; the focusing lens group G1 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged sequentially along the optical axis from the object plane to the image plane; the first lens L1 has negative optical power, the second lens L2 has negative optical power, the third lens L3 has negative optical power, and the fourth lens L4 has positive optical power; the zoom lens group G2 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged sequentially along the optical axis from the object plane to the image plane; the first lens L1 has negative optical power, the second lens L2 has negative optical power, the third lens L3 has negative optical power, and the fourth lens L4 has positive optical power; the zoom lens group G2 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged sequentially along the optical axis from the object plane to the image plane. The fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8, and ninth lens L9 are arranged sequentially from the object plane to the image plane. The optical power of the fifth lens L5 is positive, the optical power of the sixth lens L6 is positive, the optical power of the seventh lens L7 is negative, the optical power of the eighth lens L8 is positive, and the optical power of the ninth lens L9 is negative. The fixed lens group G3 includes the tenth lens L10, eleventh lens L11, twelfth lens L12, thirteenth lens L13, and fourteenth lens L14, arranged sequentially from the object plane to the image plane. The optical power of the tenth lens L10 is negative, the optical power of the eleventh lens L11 is positive, the optical power of the twelfth lens L12 is positive, and the optical power of the thirteenth lens L13 is negative. Unlike Embodiment 1, in this embodiment, the optical power of the fourteenth lens L14 is negative.

[0142] For example, Table 5 details the specific optical physical parameters of each lens in the zoom lens provided in Embodiment 2 of the present invention, according to a feasible implementation. The zoom lens in Table 5 corresponds to... Figure 9 and Figure 10 The zoom lens shown.

[0143] Table 5 Design values ​​of optical physical parameters for zoom lenses

[0144]

[0145]

[0146] The surface number is determined by the order of the lenses. For example, surface number "1" represents the object side of the first lens, surface number "2" represents the image side of the first lens, and so on. "STO" represents the aperture stop of the lens. "CG" represents flat glass. The radius of curvature represents the curvature of the lens surface. A positive value means that the surface bends towards the object side with the center closer to the image side, and a negative value means that the surface bends towards the image side with the center closer to the object side. "PL" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the center of the current surface and the next surface. The material (nd) represents the refractive index, which is 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) represents the Abbe number, which is the dispersion characteristic of the material between the current surface and the next surface. A space indicates that the current position is air.

[0147] For example, Table 6 shows the values ​​for the zoom intervals in Table 5.

[0148] Table 6. Design values ​​for the variable pitch at the wide-angle and telephoto ends of zoom lenses.

[0149] Wide-angle end telephoto end Zoom interval 1 6.5124 0.8319 Zoom interval 2 6.9273 0.3000 Zoom interval 3 0.4997 7.1270

[0150] For example, Table 7 details the aspherical coefficients of each lens in this second embodiment with a feasible implementation.

[0151] Table 7 Design values ​​of aspherical coefficient for each lens in zoom lenses.

[0152]

[0153] Where -9.79162762717249E-05 indicates that the coefficient A of face number "5" is -9.79162762717249 * 10 -5 And so on.

[0154] The zoom lens provided in this embodiment achieves the following technical specifications:

[0155] Table 8 Technical Specifications of Zoom Lenses

[0156]

[0157] Further, Figure 11 This is an axial aberration curve of a zoom lens at the wide-angle end provided in Embodiment 2 of the present invention. Figure 12 This is an axial aberration curve of a zoom lens at the telephoto end provided in Embodiment 2 of the present invention, such as... Figure 11 and Figure 12 As shown, the vertical direction represents the normalized aperture size, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal coordinate values ​​represent the axial offset relative to the specified target surface, in millimeters (mm); from Figure 11 and Figure 12 It can be seen that at both the wide-angle and telephoto ends, the axial aberrations of different wavelengths (0–1.0 normalized aperture) are all controlled within a reasonable range, indicating that the axial aberrations of the zoom lens are well controlled, meeting the basic requirement of clear imaging at night and achieving the effect of clear imaging across the entire wavelength range.

[0158] Figure 13 This is a ray fan pattern of a zoom lens at the wide-angle end, provided in Embodiment 2 of the present invention. Figure 14 This is a ray fan pattern of a zoom lens at the telephoto end provided in Embodiment 2 of the present invention, such as... Figure 13 and Figure 14 As shown, in a single image, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should perfectly coincide with the horizontal axis, in which case 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 fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 13 and Figure 14 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.

[0159] Figure 15 This is a transverse chromatic aberration diagram of a zoom lens at the wide-angle end, provided in Embodiment 2 of the present invention. Figure 16 This is a transverse chromatic aberration diagram of a zoom lens at the telephoto end provided in Embodiment 2 of the present invention, such as... Figure 15 and Figure 16As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 15 and 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.

[0160] Example 3

[0161] 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 18 As shown, the zoom lens provided by the present invention includes a focusing lens group G1, a zoom lens group G2, and a fixed lens group G3 arranged sequentially along the optical axis from the object plane to the image plane; the focusing lens group G1 and the zoom lens group G2 are movable along the optical axis; the focusing lens group G1 has negative optical power, the zoom lens group G2 has positive optical power, and the fixed lens group G3 has negative optical power; the focusing lens group G1 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged sequentially along the optical axis from the object plane to the image plane; the first lens L1 has negative optical power, the second lens L2 has negative optical power, the third lens L3 has negative optical power, and the fourth lens L4 has positive optical power; the zoom lens group G2 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged sequentially along the optical axis from the object plane to the image plane; the first lens L1 has negative optical power, the second lens L2 has negative optical power, the third lens L3 has negative optical power, and the fourth lens L4 has positive optical power; the zoom lens group G2 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged sequentially along the optical axis from the object plane to the image plane. The fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8, and ninth lens L9 are arranged sequentially from the object plane to the image plane. The optical power of the fifth lens L5 is positive, the optical power of the sixth lens L6 is positive, the optical power of the seventh lens L7 is negative, the optical power of the eighth lens L8 is positive, and the optical power of the ninth lens L9 is negative. The fixed lens group G3 includes the tenth lens L10, eleventh lens L11, twelfth lens L12, thirteenth lens L13, and fourteenth lens L14, arranged sequentially from the object plane to the image plane. The optical power of the tenth lens L10 is negative, the optical power of the eleventh lens L11 is positive, the optical power of the twelfth lens L12 is positive, and the optical power of the thirteenth lens L13 is negative. Unlike Embodiment 1, in this embodiment, the optical power of the fourteenth lens is negative.

[0162] For example, 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. The zoom lens in Table 9 corresponds to... Figure 17 and Figure 18 The zoom lens shown.

[0163] Table 9 Design values ​​of optical physical parameters for zoom lenses

[0164]

[0165]

[0166] The surface number is determined by the order of the lenses. For example, surface number "1" represents the object side of the first lens, surface number "2" represents the image side of the first lens, and so on. "STO" represents the aperture stop of the lens. "CG" represents flat glass. The radius of curvature represents the curvature of the lens surface. A positive value means that the surface bends towards the object side with the center closer to the image side, and a negative value means that the surface bends towards the image side with the center closer to the object side. "PL" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the center of the current surface and the next surface. The material (nd) represents the refractive index, which is 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) represents the Abbe number, which is the dispersion characteristic of the material between the current surface and the next surface. A space indicates that the current position is air.

[0167] For example, Table 10 shows the values ​​for the zoom intervals in Table 9.

[0168] Table 10 Design values ​​for the variable pitch at the wide-angle and telephoto ends of zoom lenses.

[0169] Wide-angle end telephoto end Zoom interval 1 6.4809 0.8414 Zoom interval 2 6.9273 0.3000 Zoom interval 3 0.4997 7.1270

[0170] For example, Table 11 details the aspherical coefficients of each lens in this embodiment three according to a feasible implementation.

[0171] Table 11 Design values ​​of aspherical coefficient for each lens in zoom lenses

[0172]

[0173]

[0174] Wherein, 3.140595422648950E-06 indicates that the coefficient A of face number "5" is 3.140595422648950 * 10 -5 And so on.

[0175] The zoom lens provided in this embodiment achieves the following technical specifications:

[0176] Table 12 Technical Specifications of Zoom Lenses

[0177]

[0178] Further, Figure 19 This is an axial aberration curve of a zoom lens at the wide-angle end provided in Embodiment 3 of the present invention. Figure 20 This is an axial aberration curve of a zoom lens at the telephoto end provided in Embodiment 3 of the present invention, such as... Figure 19 and Figure 20 As shown, the vertical direction represents the normalized aperture size, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal coordinate values ​​represent the axial offset relative to the specified target surface, in millimeters (mm); from Figure 19 and Figure 20 It can be seen that at both the wide-angle and telephoto ends, the axial aberrations of different wavelengths (0–1.0 normalized aperture) are all controlled within a reasonable range, indicating that the axial aberrations of the zoom lens are well controlled, meeting the basic requirement of clear imaging at night and achieving the effect of clear imaging across the entire wavelength range.

[0179] Figure 21 This is a ray fan pattern of a zoom lens at the wide-angle end, provided in Embodiment 3 of the present invention. Figure 22 This is a light fan pattern of a zoom lens at the telephoto end provided in Embodiment 3 of the present invention, such as... Figure 21 and Figure 22 As shown, in a single image, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should perfectly coincide with the horizontal axis, in which case 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 fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 21 and Figure 22 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.

[0180] Figure 23 This is a transverse chromatic aberration diagram of a zoom lens at the wide-angle end, provided in Embodiment 3 of the present invention. Figure 24 This is a transverse chromatic aberration diagram of a zoom lens at the telephoto end provided in Embodiment 3 of the present invention, such as... Figure 23 and Figure 24 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (µm). Figure 23 and Figure 24It 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.

[0181] 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 focusing lens group, a zoom lens group, and a fixed lens group arranged sequentially from the object plane to the image plane along the optical axis; the focusing lens group and the zoom lens group are movable along the optical axis. The focusing lens group has negative optical power, the zoom lens group has positive optical power, and the fixed lens group has negative optical power. The focusing lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged sequentially along the optical axis from the object plane to the image plane; the first lens has a negative optical power, the second lens has a negative optical power, the third lens has a negative optical power, and the fourth lens has a positive optical power. The zoom lens group includes a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the fifth lens is positive, the optical power of the sixth lens is positive, the optical power of the seventh lens is negative, the optical power of the eighth lens is positive, and the optical power of the ninth lens is negative. The fixed lens group includes a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, and a fourteenth lens arranged sequentially from the object plane to the image plane along the optical axis; the tenth lens has a negative optical power, the eleventh lens has a positive optical power, the twelfth lens has a positive optical power, the thirteenth lens has a negative optical power, and the fourteenth lens has either a positive or negative optical power.

2. The zoom lens according to claim 1, characterized in that, The surface of the lens adjacent to the object plane is the object-side surface, and the surface of the lens adjacent to the image plane is the image-side surface; In the focusing lens group, the first lens is a convex-concave lens, the second lens is a convex-concave lens, the third lens is a biconcave lens, and the object-side surface of the fourth lens convexes towards the object surface. In the zoom lens group, the object-side surface of the fifth lens convexes towards the object surface, the sixth lens is a biconvex lens, the seventh lens is a convex-concave lens, the eighth lens is a biconvex lens, and the ninth lens is a concave-convex lens. In the fixed lens group, the tenth lens is a biconcave lens, the object-side surface of the eleventh lens is convex toward the object surface, the twelfth lens is a biconvex lens, the thirteenth lens is a meniscus lens, and the paraxial region of the image-side surface of the fourteenth lens is concave toward the image surface.

3. The zoom lens according to claim 1, characterized in that, In the focusing lens group, the third lens is a glass aspherical lens, and the remaining lenses are glass spherical lenses; In the zoom lens group, the fifth lens is a glass aspherical lens, and the remaining lenses are glass spherical lenses; In the fixed lens group, the fourteenth lens is a glass aspherical lens, and the remaining lenses are glass spherical lenses.

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 fifth lens has a refractive index of nd5 and an Abbe number of vd5; the sixth lens has a refractive index of nd6 and an Abbe number of vd6; the thirteenth lens has a refractive index of nd13 and an Abbe number of vd13; the fourteenth lens has a refractive index of nd14 and an Abbe number of vd14; wherein: 1.43≤nd1≤1.50; 70.47≤vd1≤95.25; 1.53≤nd5≤1.60; 55.47≤vd5≤71.69; 1.43≤nd6≤1.50; 81.50≤vd6≤95.10; 1.75≤nd13≤1.93; 20.10≤vd13≤52.40 1.75≤nd14≤1.86;40.00≤vd14≤52.40; 5. The zoom lens according to claim 1, characterized in that, The focal length of the focusing lens group is F1, the focal length of the zoom lens group is F2, the focal length of the fixed lens group is F3, and the focal length of the zoom lens at the telephoto end is FT, wherein: -0.77≤F1 / FT≤-0.76; 0.85≤F2 / FT≤1.04; -21.6≤F3 / FT≤-9.

5.

6. The zoom lens according to claim 1, characterized in that, The movable range of the focusing lens group is S1, the total length of the zoom lens at the wide-angle end is TTLW, and the maximum lens diameter in the focusing lens group is ΦG1, wherein: 0.1≤S1 / TTLW≤0.11; 0.42 < ΦG1 / TTLW < 0.

451.

7. The zoom lens according to claim 1, characterized in that, In the zoom lens group, the seventh lens, the eighth lens, and the ninth lens form a first cemented lens. The focal length of the first cemented lens is EFL1, the focal length of the zoom lens group is F2, the refractive index of the eighth lens is nd8, and the Abbe number is vd8. 1.43≤nd8≤1.50;81.60≤vd8≤95.24; -2.15≤EFL1 / F2≤-0.

92.

8. The zoom lens according to claim 1, characterized in that, In the fixed lens group, the tenth lens and the eleventh lens form a second cemented lens, the focal length of the second cemented lens is EFL2, the focal length of the zoom lens at the telephoto end is FT, the diameter of the fourteenth lens is Φ14, and the axial distance between the edge and the center of the fourteenth lens at its maximum thickness is S14, wherein: -2.11≤EFL2 / FT≤-1; 0.075≤S14 / Φ14≤0.

18.

9. The zoom lens according to claim 1, characterized in that, The zoom lens has a focal length of FT at the telephoto end and a focal length of FW at the wide-angle end, where: FT / FW ≥ 2.

20.

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

Images