A zoom lens

Abstract

The application discloses a zoom lens, which comprises, in sequence from an object side to an image side along an optical axis, a focusing lens group with negative refractive power, a diaphragm, a variable magnification lens group with positive refractive power, and a fixed lens group with negative refractive power; the focusing lens group comprises a first lens with negative refractive power, a second lens with negative refractive power, and a third lens with positive refractive power; the variable magnification lens group comprises a fourth lens with positive refractive power, a fifth lens with negative refractive power, a sixth lens with positive refractive power, a seventh lens with negative refractive power, an eighth lens with positive refractive power, and a ninth lens with positive or negative refractive power; the lens group composed of the seventh lens and the eighth lens has negative or positive refractive power; the fixed lens group comprises a tenth lens with negative refractive power and an eleventh lens with positive refractive power; and the focusing lens group and the variable magnification lens group are arranged by moving along the direction of the optical axis. The above technical scheme can realize a zoom lens with a large aperture, a large target surface, high image quality, and a small size.

Description

Technical Field

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

[0003] With the development of technology, cameras are gradually moving towards miniaturization and refinement, which also puts forward more stringent requirements for mainstream zoom lenses.

[0004] Therefore, how to achieve zoom lenses with large aperture, large sensor size, high image quality, and small size has become an urgent technical problem to be solved. Summary of the Invention

[0005] This invention provides a zoom lens that achieves a large aperture, large focal length, high image quality, and small size.

[0006] According to the content of this application, a zoom lens is provided, comprising: a focusing lens group with negative optical power, an aperture stop, a zoom lens group with positive optical power, and a fixed lens group with negative optical power, arranged sequentially along the optical axis from the object side to the image side. The focusing lens group includes a first lens with negative optical power, a second lens with negative optical power, and a third lens with positive optical power; The zoom lens group includes a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power, and a ninth lens with either positive or negative optical power; wherein the optical power of the lens group formed by the seventh lens and the eighth lens is either negative or positive. The fixed lens group includes a tenth lens with negative optical power and an eleventh lens with positive optical power; The focusing lens group and the zoom lens group are moved along the direction of the optical axis; when the focusing lens group and the zoom lens group move together along the direction of the optical axis, the zoom lens can switch between the wide-angle end and the telephoto end.

[0007] Optionally, in the focusing lens group, the image-side surface of the first lens is concave, the object-side surface and the image-side surface of the second lens are both concave, the object-side surface of the third lens is convex, and the image-side surface of the third lens is concave. In the fixed lens group, the object-side surface of the tenth lens is convex, the image-side surface of the tenth lens is concave, the object-side surface of the eleventh lens is convex, and the image-side surface of the eleventh lens is concave.

[0008] Optionally, 2.200 ≤ FT / FW ≤ 2.250; Wherein, FT is the focal length of the zoom lens at the telephoto end, and FW is the focal length of the zoom lens at the wide-angle end.

[0009] Optionally, -2.809 ≤ F1q / FW ≤ -2.343; 2.358≤F2q / FW≤2.519; -31.744≤F3q / FW≤-21.870; Wherein, F1q is the focal length of the focusing lens group, F2q is the focal length of the zoom lens group, F3q is the focal length of the fixed lens group, and FW is the focal length of the zoom lens at the wide-angle end.

[0010] Optionally, the fourth lens, the ninth lens, and the eleventh lens are all aspherical lenses.

[0011] Optionally, the fifth lens and the sixth lens form a cemented lens group, and the seventh lens and the eighth lens form a cemented lens group; 1.190≤F56 / F2q≤1.485; -3.294≤F78 / F2q≤4.464; Wherein, F56 is the focal length of the cemented lens group composed of the fifth lens and the sixth lens, F78 is the focal length of the cemented lens group composed of the seventh lens and the eighth lens, and F2q is the focal length of the zoom lens group.

[0012] Optionally, the fifth lens and the sixth lens form a cemented lens group, and the seventh lens and the eighth lens form a cemented lens group; 1.652≤nd5≤1.703; 48.080≤vd5≤58.403; 1.571≤nd6≤1.594; 60.475≤vd6≤71.616; 1.640≤nd7≤1.673; 32.171≤vd7≤34.465; 1.497≤nd8≤1.571; 71.616≤vd8≤81.608; Wherein, nd5 is the refractive index of the fifth lens, nd6 is the refractive index of the sixth lens, nd7 is the refractive index of the seventh lens, nd8 is the refractive index of the eighth lens, vd5 is the Abbe number of the fifth lens, vd6 is the Abbe number of the sixth lens, vd7 is the Abbe number of the seventh lens, and vd8 is the Abbe number of the eighth lens.

[0013] Optional, 1.497≤nd1≤1.554; 71.762≤vd1≤81.608; 1.500≤nd2≤1.550、66.021≤vd2≤75.225; 2.001≤nd3≤2.104;17.018≤vd3≤25.458; 1.497≤nd4≤1.528; 70.371≤vd4≤81.612; 1.821≤nd9≤1.884;37.199≤vd9≤42.706; 1.834≤nd11≤2.002; 20.700≤vd11≤37.285; Wherein, nd1 is the refractive index of the first lens, nd2 is the refractive index of the second lens, nd3 is the refractive index of the third lens, nd4 is the refractive index of the fourth lens, nd9 is the refractive index of the ninth lens, nd11 is the refractive index of the eleventh lens, vd1 is the Abbe number of the first lens, vd2 is the Abbe number of the second lens, vd3 is the Abbe number of the third lens, vd4 is the Abbe number of the fourth lens, vd9 is the Abbe number of the ninth lens, and vd11 is the Abbe number of the eleventh lens.

[0014] Optionally, 1.701 ≤ S1 / S2 ≤ 2.366; Wherein, S1 is the maximum distance that the focusing lens group can move, and S2 is the maximum distance that the zoom lens group can move.

[0015] Optionally, 2.220 ≤ TTL / ΦG1 ≤ 2.548 Wherein, TTL is the total length of the optical system of the zoom lens at the wide-angle end, and ΦG1 is the maximum lens diameter in the focusing lens group.

[0016] Optionally, 25.963 ≤ TTL / M ≤ 29.096; Wherein, TTL is the total length of the optical system of the zoom lens at the wide-angle end, and M is the zoom ratio of the zoom lens.

[0017] The technical solution of this application provides a zoom lens with powerful image acquisition capabilities. While meeting the requirements of high resolution and a large image sensor, it ensures large aperture zoom across the entire focal length range and can still capture high-definition images even with insufficient external lighting. It boasts a long focal length, a large aperture, and a large magnification, while maintaining minimal optical distortion at both the wide-angle and telephoto ends, meeting high-quality imaging requirements and making the zoom lens suitable for a wider range of applications. The zoom lens provided in this embodiment uses eleven lenses, giving it advantages such as a large aperture, a large image sensor, high definition, and small size. It achieves full-band confocal focusing and 2.2X zoom in the visible light band at a 1 / 1.7″ image sensor, resulting in a zoom lens with a large aperture, a large image sensor, high image quality, and a small size.

[0018] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] 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 by an embodiment of the present invention; Figure 3 A transverse chromatic aberration curve of a zoom lens at the wide-angle end is provided in an embodiment of the present invention; Figure 4 An axial aberration map of a zoom lens at the wide-angle end, provided as an embodiment of the present invention; Figure 5 A ray fan pattern of a zoom lens at the wide-angle end is provided for an embodiment of the present invention; Figure 6 A vertical chromatic aberration curve of a zoom lens at the telephoto end is provided as an embodiment of the present invention; Figure 7 An axial aberration map of a zoom lens at the telephoto end is provided for an embodiment of the present invention; Figure 8 A ray fan pattern of a zoom lens at the telephoto end is provided for an embodiment of the present invention; Figure 9This is a schematic diagram of another zoom lens at the wide-angle end provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of another zoom lens at the telephoto end provided in an embodiment of the present invention; Figure 11 Another lateral chromatic aberration curve of a zoom lens at the wide-angle end provided in an embodiment of the present invention; Figure 12 An axial aberration diagram at the wide-angle end of another zoom lens provided in an embodiment of the present invention; Figure 13 Another zoom lens ray fan pattern at the wide-angle end provided in an embodiment of the present invention; Figure 14 Another vertical chromatic aberration curve of a zoom lens at the telephoto end provided in an embodiment of the present invention; Figure 15 Another zoom lens provided in this embodiment of the invention has an axial aberration diagram at the telephoto end; Figure 16 Another ray fan pattern of a zoom lens at the telephoto end provided in an embodiment of the present invention; Figure 17 This is a schematic diagram of the structure of another zoom lens at the wide-angle end provided in an embodiment of the present invention; Figure 18 This is a schematic diagram of the structure of another zoom lens at the telephoto end provided in an embodiment of the present invention; Figure 19 This invention provides another example of a zoom lens's lateral chromatic aberration curve at the wide-angle end. Figure 20 An axial aberration diagram of a zoom lens at the wide-angle end, provided as an embodiment of the present invention; Figure 21 Another ray fan pattern of a zoom lens at the wide-angle end provided in an embodiment of the present invention; Figure 22 This invention provides another type of vertical chromatic aberration curve for a zoom lens at the telephoto end; Figure 23 An axial aberration diagram of a zoom lens at the telephoto end, provided as an embodiment of the present invention; Figure 24 This is another example of a zoom lens at the telephoto end provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be fully described below with reference to the accompanying drawings of the embodiments of this invention through specific implementation methods. Obviously, the described embodiments are only some, not all, embodiments of this invention. Various modifications and variations can be made to this invention without departing from the spirit or scope of this invention, which will be obvious to those skilled in the art. Therefore, this invention is intended to cover modifications and variations of this invention that fall within the scope of the corresponding claims (the claimed technical solutions) and their equivalents.

[0022] Furthermore, the terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, terms such as "an," "one," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "including" or "comprising" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their 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 only used to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes. In addition, descriptions of "same" or "equal" in the embodiments of this disclosure do not mean that two objects are completely equal in size or shape; they are allowed to be approximately the same or approximately equal within a certain error range.

[0023] It should be noted that the implementation methods provided in the embodiments of the present invention can be combined with each other without contradiction.

[0024] 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 according to an embodiment of the present invention, with reference to... Figure 1 and Figure 2The zoom lens includes: a focusing lens group G1 with negative optical power, an aperture stop STO, a zoom lens group G2 with positive optical power, and a fixed lens group G3 with negative optical power, arranged sequentially along the optical axis from the object side to the image side. The focusing lens group G1 includes a first lens L1 with negative optical power, a second lens L2 with negative optical power, and a third lens L3 with positive optical power. The zoom lens group G2 includes a fourth lens L4 with positive optical power, a fifth lens L5 with negative 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 either positive or negative optical power; wherein the lens group consisting of the seventh and eighth lenses has either negative or positive optical power. The fixed lens group G3 includes a tenth lens L10 with negative optical power and an eleventh lens L11 with positive optical power. The focusing lens group G1 and the zoom lens group G2 are moved along the optical axis; when the focusing lens group G1 and the zoom lens group G2 move together along the optical axis, the zoom lens can switch between the wide-angle end and the telephoto end.

[0025] The focusing lens group G1, the aperture stop STO, the zoom lens group G2, and the fixed lens group G3 can be arranged in one lens barrel. Figure 1 and Figure 2 (Not shown in the image) Within the lens barrel, the fixed lens group G3 is fixed in position, remaining stationary relative to the image plane. The focusing lens group G1 and the zoom lens group G2 can reciprocate along the optical axis within the lens barrel. Through the coordinated 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. The zoom lens's aperture stop STO is located between the positive optical power third lens L3 and the positive optical power fourth lens L4. By changing the positions of the focusing lens group G1 and the zoom lens group G2 on the optical axis, the zoom lens can be switched between wide-angle and telephoto ends at any time.

[0026] It is understandable that during the zoom process achieved by moving the focusing lens group G1 and the zoom lens group G2, the zoom lens is at its widest 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.

[0027] In this embodiment of the invention, setting a negative optical power focusing lens group G1 before the aperture stop STO of the zoom lens ensures that a larger light aperture is generated after light passes through, increasing the aperture of the optical system and ensuring clear imaging of objects at different distances simultaneously, as well as clear imaging in low-light environments, meeting the usage requirements under different conditions. The focusing lens group G1, in conjunction with the fourth lens L4 in the zoom lens group G2, allows light to pass smoothly through the aperture stop STO, avoiding stray light such as reflections at the aperture stop STO, while also adjusting the aberrations of the zoom lens to a certain extent, ensuring aberration balance and stable high and low temperature performance of the zoom lens. The fifth lens L5 to the ninth lens L9 in the zoom lens group G2 can correct aberrations at the rear end of the zoom lens, and together with the focusing lens group G1 in front of the aperture stop STO, can stabilize the imaging quality of the optical system. The combination of the zoom lens group G2 and the tenth lens L10 and eleventh lens L11 in the fixed lens group G3 can minimize the lens's advanced aberrations, increase the lens target area (size), improve image quality, shorten the overall system length, and meet the usage requirements in more situations.

[0028] It should be noted that optical power is equal to the difference between the image-side convergence and the object-side convergence, and its value is the reciprocal of the focal length. It characterizes the ability of an optical system to deflect light rays. The larger the absolute value of optical power, the stronger the bending ability of light rays; the smaller the absolute value of optical power, the weaker the bending ability of light rays. 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).

[0029] In this embodiment of the invention, by setting a first lens L1 with negative optical power, a second lens L2 with negative optical power, and a third lens L3 with positive optical power in the focusing lens group G1, the focusing lens group G1 has negative optical power; in the zoom lens group G2, a fourth lens L4 with positive optical power, a fifth lens L5 with negative 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 with either positive or negative optical power are set. Lens L9 provides positive optical power to the zoom lens group G2. In the fixed lens group G3, a tenth lens L10 with negative optical power and an eleventh lens L11 with positive optical power are configured, giving the fixed lens group G3 a negative optical power. Specifically, when the lens group composed of the seventh lens L7 and the eighth lens L8 has negative optical power, the ninth lens L9 has positive optical power; conversely, when the lens group composed of the seventh lens L7 and the eighth lens L8 has positive optical power, the ninth lens L9 has negative optical power. This allows the optical powers of each lens group to work together, ensuring that the zoom lens can have a large aperture and a long focal length. Simultaneously, after light enters through the focusing lens group G1, it can smoothly pass through each lens group, which helps reduce aberrations and chromatic aberration in the zoom lens, ensuring high image quality.

[0030] Furthermore, an aperture stop STO is placed between the focusing lens group G1 and the zoom lens group G2. The aperture stop STO can adjust the propagation direction of the light beam, which helps to improve image quality. By placing the aperture stop STO between the focusing lens group G1 and the zoom lens group G2, the advanced aberrations of the zoom lens can be controlled at the front end, ensuring that the rear end of the zoom lens has a high image height. This expands the imaging target area while improving image quality, making the zoom lens suitable for different application scenarios.

[0031] For example, a planar glass lens CG is also provided along the direction from the object plane to the image plane; the planar glass lens CG is located on one side of the image surface of the eleventh lens L11. The planar glass lens CG can protect the photosensitive chip in the imaging sensor, wherein the photosensitive chip is used to convert the light signal collected by the zoom lens into an electrical signal, thereby ensuring the imaging effect of the zoom lens.

[0032] In summary, the zoom lens provided in this embodiment of the invention possesses powerful image acquisition capabilities. While meeting the requirements of high resolution and a large image sensor, it can ensure large aperture zoom across the entire focal length range and still capture high-definition images even with insufficient external lighting. It features a long focal length, a large aperture, and a large magnification, while maintaining minimal optical distortion at both the wide-angle and telephoto ends, meeting high-quality imaging requirements and making the zoom lens suitable for a wider range of applications. The zoom lens provided in this embodiment of the invention uses eleven lenses, giving it advantages such as a large aperture, a large image sensor, high definition, and small size. It can achieve full-spectrum confocal focusing and 2.2X zoom in the visible light band at a 1 / 1.7″ image sensor, resulting in a zoom lens with a large aperture, a large image sensor, high image quality, and a small size.

[0033] In some embodiments, the zoom lens provided in this invention has an F-number of 1.05-1.55.

[0034] In some embodiments, the zoom lens provided in this invention has a focal length of 5.15mm-11.5mm.

[0035] In some embodiments, the zoom lens provided in this invention is adapted to a 9.4mm target surface.

[0036] In some embodiments, the zoom lens provided by the present invention has an FOVW / FOVT ratio of 2.659, where FOVW is the maximum field of view of the zoom lens at the wide-angle end and FOVT is the maximum field of view of the zoom lens at the telephoto end. By controlling the ratio of the field of view of the zoom lens at the wide-angle end and the telephoto end, the zoom range and focal length range of the lens can be controlled to meet the usage needs under more conditions.

[0037] Optionally, in the focusing lens group G1, the image-side surface of the first lens L1 is concave, the object-side and image-side surfaces of the second lens L2 are both concave, and the object-side and image-side surfaces of the third lens L3 are both convex. In the fixed lens group G3, the object-side and image-side surfaces of the tenth lens L10 are both convex and concave, and the object-side and image-side surfaces of the eleventh lens L11 are both convex and concave. This arrangement allows light rays from the object side to pass smoothly through the zoom lens, effectively reducing optical distortion and improving image quality.

[0038] For example, the object-side surface of the first lens L1 can be convex or concave, the object-side surface of the fourth lens L4 is convex, and the image-side surface of the fourth lens L4 can be convex or concave, the object-side surface of the fifth lens L5 is convex, and the image-side surface of the fifth lens L5 is concave, both the object-side surface and the image-side surface of the sixth lens L6 are convex, both the object-side surface and the image-side surface of the seventh lens L7 are concave, the object-side surface of the eighth lens L8 is convex, and the image-side surface of the eighth lens L8 can be convex or concave, and the object-side surface of the ninth lens L9 is convex, and the image-side surface of the ninth lens L9 can be concave or convex.

[0039] It is important to note that Figure 1 , Figure 2 The structural diagrams in the following embodiments are for illustrative purposes only, and shapes such as aspherical surfaces are not represented in accordance with actual conditions.

[0040] Optionally, 2.200 ≤ FT / FW ≤ 2.250; where FT is the focal length of the zoom lens at the telephoto end, and FW is the focal length of the zoom lens at the wide-angle end. By controlling the ratio of the focal length at the wide-angle end to that at the telephoto end, the zoom range and focal length range of the zoom lens can be controlled to meet the usage needs under more conditions.

[0041] Optionally, -2.809 ≤ F1q / FW ≤ -2.343; 2.358 ≤ F2q / FW ≤ 2.519; -31.744 ≤ F3q / FW ≤ -21.870; where F1q is the focal length of the focusing lens group G1, F2q is the focal length of the zoom lens group G2, F3q is the focal length of the fixed lens group G3, and FW is the focal length of the zoom lens at the wide-angle end. This allows for a reasonable combination of optical power, enabling light to pass through the zoom lens more smoothly and significantly correcting the impact of advanced aberrations on image quality.

[0042] Optionally, the fourth lens L4, the ninth lens L9, and the eleventh lens L11 are all aspherical lenses.

[0043] Among them, aspherical lenses have a better correction effect on advanced aberrations. When used in conjunction with other lenses in the group, they can not only reduce the aberrations of the system and improve image quality, but also correct the aberrations of the group itself, so that the zoom lens has better image quality throughout the zoom process.

[0044] Specifically, higher aberrations are generated after light passes through the aperture stop STO. By setting the fourth lens L4 in the zoom lens group G2 as an aspherical lens, higher aberrations can be reduced at the front end after light passes through the aperture stop STO. By setting the ninth lens L9 in the zoom lens group G2 as an aspherical lens, higher aberrations at the rear end can be reduced. By setting the eleventh lens L11 in the fixed lens group G3 as an aspherical lens, it is beneficial to correct aberrations at the rear end of the lens. The aspherical lenses of the fourth lens L4, the ninth lens L9, and the eleventh lens L11, together with the focusing lens group G1 at the front end of the aperture stop, can stabilize the imaging quality of the optical system.

[0045] In some embodiments, the fourth lens L4, the ninth lens L9, and the eleventh lens L11 are all glass aspherical lenses, while the first lens L1, the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the tenth lens L10 are all glass spherical lenses.

[0046] In some embodiments, the fifth lens L5 and the sixth lens L6 form a cemented lens group, and the seventh lens L7 and the eighth lens L8 form a cemented lens group.

[0047] Optionally, 1.190≤F56 / F2q≤1.485; -3.294≤F78 / F2q≤4.464; where F56 is the focal length of the cemented lens group composed of the fifth lens L5 and the sixth lens L6, F78 is the focal length of the cemented lens group composed of the seventh lens L7 and the eighth lens L8, and F2q is the focal length of the zoom lens group G2.

[0048] Specifically, during the zooming process of the optical system, the zoom lens group G2 is responsible for zooming the optical system with a changed focal length. By setting two cemented lens groups and reasonably setting the optical power of the two cemented lens groups, chromatic aberration and higher aberrations generated in the zoom lens group G2 can be corrected, greatly reducing the aberration pressure of other groups of the lens at different focal lengths, thereby enabling the optical system to focus across the entire focal length.

[0049] Optionally, 1.652≤nd5≤1.703; 48.080≤vd5≤58.403; 1.571≤nd6≤1.594; 60.475≤vd6≤71.616; 1.640≤nd7≤1.673; 32.171≤vd7≤34.465; 1.497≤nd8≤1.571;71.616≤vd8≤81.608;where nd5 is the refractive index of the fifth lens L5, nd6 is the refractive index of the sixth lens L6, nd7 is the refractive index of the seventh lens L7, nd8 is the refractive index of the eighth lens L8, vd5 is the Abbe number of the fifth lens L5, vd6 is the Abbe number of the sixth lens L6, vd7 is the Abbe number of the seventh lens L7, and vd8 is the Abbe number of the eighth lens L8.

[0050] For example, the fifth lens L5 and the sixth lens L6 form a cemented lens group, and the seventh lens L7 and the eighth lens L8 form another cemented lens group. These two groups can correct chromatic aberration and higher-order aberrations in the optical system. Therefore, the selection of materials for the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 is crucial. Cementing two different glass materials can effectively correct chromatic aberration and higher-order aberrations. For instance, a flint glass lens with a lower Abbe number and a crown glass lens with a higher Abbe number can be cemented together. A combination with a large difference in Abbe number can further eliminate chromatic aberration in the optical system, thus achieving 2.2X confocal focusing in the visible light band.

[0051] Optional, 1.497≤nd1≤1.554; 71.762≤vd1≤81.608; 1.500≤nd2≤1.550、66.021≤vd2≤75.225; 2.001≤nd3≤2.104;17.018≤vd3≤25.458; 1.497≤nd4≤1.528; 70.371≤vd4≤81.612; 1.821≤nd9≤1.884;37.199≤vd9≤42.706; 1.834≤nd11≤2.002;20.700≤vd11≤37.285;wherein, nd1 is the refractive index of the first lens L1, nd2 is the refractive index of the second lens L2, nd3 is the refractive index of the third lens L3, nd4 is the refractive index of the fourth lens L4, nd9 is the refractive index of the ninth lens L9, nd11 is the refractive index of the eleventh lens L11, vd1 is the Abbe number of the first lens L1, vd2 is the Abbe number of the second lens L2, vd3 is the Abbe number of the third lens L3, vd4 is the Abbe number of the fourth lens L4, vd9 is the Abbe number of the ninth lens L9, and vd11 is the Abbe number of the eleventh lens L11.

[0052] For the focusing lens group G1, the first lens L1, the second lens L2 and the third lens L3 use the same material combination as the above lenses, which can control the chromatic aberration and aberration entering the zoom lens group within a reasonable range, and prevent them from being excessively magnified during the movement of the zoom lens group, which would make them difficult to correct later.

[0053] For the zoom lens group G2, it plays a dominant role in adjusting the lens magnification. The fourth lens L4 and the ninth lens L9, using materials with the aforementioned refractive index and Abbe number, can correct chromatic aberration and aberrations generated throughout the lens, controlling them within a reasonable range before light enters the image plane. In addition, when the fourth lens L4 and the ninth lens L9 are aspherical lenses, they have a good ability to control higher aberrations of the optical system. The use of aspherical lenses for the fourth lens L4 and the ninth lens L9 can further reduce higher aberrations when light enters the image plane, thereby further improving image quality and meeting the requirements of 4K imaging.

[0054] For the fixed lens group G3, the eleventh lens L11 adopts the refractive index combination of the above lenses, which can reduce the number of lenses required for the fixed lens group G3, and better control the exit angle of the zoom lens before the light enters the image, thereby controlling the image quality and target size of the lens.

[0055] Optionally, 1.701 ≤ S1 / S2 ≤ 2.366; where S1 is the maximum movable distance of the focusing lens group G1, and S2 is the maximum movable distance of the zoom lens group G2. By controlling the moving distances of the focusing lens group G1 and the zoom lens group G2, the volume and range of motion of the focusing lens group G1 can be minimized to the greatest extent, which can significantly reduce the size of the zoom lens, while ensuring that the focusing lens group G1 and the zoom lens group G2 have sufficient travel and do not collide with the fixed groups.

[0056] Optionally, 2.220≤TTL / ΦG1≤2.548, where TTL is the total length of the optical system of the zoom lens at the wide-angle end, and ΦG1 is the maximum lens diameter in the focusing lens group. This allows for control over the lens size, making the lens more compact while maximizing the field of view and light intake to meet usage needs in different environments.

[0057] Optionally, 25.963 ≤ TTL / M ≤ 29.096; where TTL is the total length of the optical system of the zoom lens at the wide-angle end, and M is the zoom ratio of the zoom lens. By limiting the total lens length and zoom ratio, the lens space can be compressed, ensuring that the required image quality and zoom range are met while maintaining a small lens size.

[0058] By allocating parameters such as lens surface type, radius of curvature, thickness, and material of each lens in the zoom lens, this invention can ultimately achieve a zoom lens with full-band confocal focusing, 2.2X zoom, large aperture, large target surface, and clear imaging under a 1 / 1.7″ target surface and in the visible light band.

[0059] In one exemplary embodiment, Table 1 details a feasible implementation. Figure 1 and Figure 2 The specific parameters of the zoom lens shown are as follows.

[0060] Table 1. Parameter Design of a Zoom Lens Table 2 shows the design parameters of a zoom lens corresponding to Table 1, including lens surface type, radius of curvature, thickness, and materials.

[0061] Table 2. Design of optical physical parameters for zoom lenses. In Table 2, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens L1, surface number 2 represents the image side of the first lens L1, and so on. "STO" represents the aperture stop of the zoom lens; IMA represents the image plane; the radius of curvature represents the curvature of the corresponding lens surface in mm, with a positive value indicating that the surface bends towards the image plane and a negative value indicating that the surface bends towards the object plane. "INF" indicates that the surface is flat and the radius of curvature is infinite; the thickness represents the central axial distance between the current surface and the next surface in mm; the refractive index represents the ability of the material between the current surface and the next surface to deflect light, with a blank space indicating that the current position is air and the refractive index is 1; the Abbe number represents the ability of the material between the current surface and the next surface to disperse light, with a blank space indicating that the current position is air and the Abbe number is 1.

[0062] Table 3 shows the design parameters for the zoom interval at the wide-angle and telephoto ends of a zoom lens corresponding to Table 2.

[0063] Table 3. A zoom interval design for the wide-angle and telephoto ends of zoom lenses. Table 4 shows the aspheric coefficient values ​​used in the current embodiment.

[0064] Table 4 Aspherical coefficients of a zoom lens The k values ​​in Table 4 represent the numerical values ​​of the best-fit conic coefficients for the aspheric surface. The conic coefficients of the aspheric surface can be defined using the following aspheric formula, but are not limited to these representations: ; Where z is the axial sagitta in the Z direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature; and k is the fitted conic coefficient. , , , , , , These are the higher-order aspheric coefficients corresponding to the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders of aspheric surfaces. These can be combined to form higher-order terms for the corresponding aspherical surfaces.

[0065] Based on the above parameter design, Table 5 shows the lens parameters of the zoom lens implemented in this embodiment.

[0066] Table 5 Lens parameters of a zoom lens Figure 3 This invention provides a vertical chromatic aberration curve for a zoom lens at the wide-angle end, as part of an embodiment of the invention. Figure 3 This is the transverse chromatic aberration curve at infinity at the wide-angle end of the optical system; the vertical axis represents the field of view, 0 indicates on the optical axis, and the vertex of the vertical axis represents the maximum image height; the dominant wavelength is 546nm, and the horizontal axis represents the offset relative to the dominant wavelength, in micrometers. ).Depend on Figure 3 It can be seen that the chromatic aberration along the vertical axis is controlled within a small range for different wavelengths, indicating that the zoom lens has good control over the chromatic aberration along the vertical axis at the wide-angle end, which can meet the application requirements under normal conditions.

[0067] Figure 4 This invention provides an axial aberration diagram of a zoom lens at the wide-angle end, as part of an embodiment of the invention. Axial aberration diagrams are one of the commonly used evaluation methods by optical designers. Figure 4 This is an axial aberration diagram of the optical system at infinity at the wide-angle end. The vertical direction represents the normalized aperture, with 0 indicating the optical axis and the vertical vertex representing the maximum pupil radius. The horizontal direction represents the offset relative to the ideal focal point, in millimeters (mm). Different linear curves in the diagram represent different wavelengths of the system's imaging, derived from... Figure 4 It can be seen that the axial aberrations of the normalized apertures of different wavelengths (0-1.0) are all controlled within a reasonable range, indicating that the spherical aberration of the optical system is well controlled at each wavelength; it can meet the requirements of wide-spectrum applications.

[0068] Figure 5 This invention provides a ray fan plot of a zoom lens at the wide-angle end, as part of an embodiment. Ray fan plots are a commonly used evaluation method by optical designers. For example... Figure 5As 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, 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 fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 5 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.

[0069] Figure 6 This invention provides a vertical chromatic aberration curve for a zoom lens at the telephoto end. Figure 6 This is the transverse chromatic aberration curve at infinity at the telephoto end of the optical system. The vertical axis represents the field of view, with 0 indicating the optical axis is on the line of sight. The vertex of the vertical axis represents the maximum image height. The dominant wavelength is 546 nm. The horizontal axis represents the offset relative to the dominant wavelength, in micrometers. ).Depend on Figure 6 It can be seen that the chromatic aberration along the vertical axis is controlled within a small range for different wavelengths, indicating that the zoom lens has good control over the chromatic aberration along the vertical axis at the telephoto end, which can meet the application requirements under normal conditions.

[0070] Figure 7 This invention provides an axial aberration map of a zoom lens at the telephoto end. Axial aberration maps are one of the commonly used evaluation methods by optical designers. Figure 7 This is an axial aberration diagram of the optical system at infinity at the telephoto end. The vertical direction represents the normalized aperture, with 0 indicating on the optical axis, and the vertical vertex representing the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focal point, in millimeters (mm). Different linear curves in the diagram represent different wavelengths of the system's imaging, derived from... Figure 7 It can be seen that the axial aberrations of the normalized apertures of different wavelengths (0-1.0) are all controlled within a reasonable range, indicating that the spherical aberration of the optical system is well controlled at each wavelength; it can meet the requirements of wide-spectrum applications.

[0071] Figure 8 This invention provides a ray fan plot of a zoom lens at the telephoto end. Ray fan plots are a commonly used evaluation method by optical designers. For example... Figure 8As 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, 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 fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 8 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.

[0072] In another exemplary embodiment, Figure 9 This is a schematic diagram of another zoom lens at the wide-angle end provided in an embodiment of the present invention. Figure 10 Table 6 provides a schematic diagram of another zoom lens at the telephoto end, illustrating another feasible implementation method. Figure 9 and Figure 10 The specific parameters of the zoom lens shown are as follows.

[0073] Table 6. Another parameter design for zoom lenses Table 7 shows the design parameters of a zoom lens, including lens surface type, radius of curvature, thickness, and materials, corresponding to those in Table 6.

[0074] Table 7. Another optical physical parameter design for zoom lenses In Table 7, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens L1, surface number 2 represents the image side of the first lens L1, and so on. "STO" represents the aperture stop of the zoom lens; IMA represents the image plane; the radius of curvature represents the curvature of the corresponding lens surface in mm, with a positive value indicating that the surface bends towards the image plane and a negative value indicating that the surface bends towards the object plane. "INF" indicates that the surface is flat and the radius of curvature is infinite; the thickness represents the axial distance between the current surface and the next surface in mm; the refractive index represents the ability of the material between the current surface and the next surface to deflect light, with a blank space indicating that the current position is air and the refractive index is 1; the Abbe number represents the ability of the material between the current surface and the next surface to disperse light, with a blank space indicating that the current position is air and the Abbe number is 1.

[0075] Table 8 shows the design parameters for the zoom interval at the wide-angle and telephoto ends of a zoom lens corresponding to Table 7.

[0076] Table 8. Alternative zoom interval design for the wide-angle and telephoto ends of zoom lenses. Table 9 shows the aspheric coefficient values ​​used in the current embodiment.

[0077] Table 9 Aspherical coefficients of another zoom lens The k values ​​in Table 9 represent the numerical values ​​of the best-fit conic coefficients for the aspheric surface. The conic coefficients of the aspheric surface can be defined using the following aspheric formula, but are not limited to the following representations: ; Where z is the axial sagitta in the Z direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature; and k is the fitted conic coefficient. , , , , , , These are the higher-order aspheric coefficients corresponding to the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders of aspheric surfaces. These can be combined to form higher-order terms for the corresponding aspherical surfaces.

[0078] Based on the above parameter design, Table 10 shows the lens parameters of the zoom lens implemented in this embodiment.

[0079] Table 10 Lens parameters of another zoom lens Figure 11 Another zoom lens with a vertical chromatic aberration curve at the wide-angle end, provided as an embodiment of the present invention. Figure 11 This is the transverse chromatic aberration curve at infinity at the wide-angle end of the optical system; the vertical axis represents the field of view, 0 indicates on the optical axis, and the vertex of the vertical axis represents the maximum image height; the dominant wavelength is 546nm, and the horizontal axis represents the offset relative to the dominant wavelength, in micrometers. ).Depend on Figure 11 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a small range, indicating that the transverse chromatic aberration of the zoom optical system is well controlled at the wide-angle end, which can meet the application requirements under normal conditions.

[0080] Figure 12 This invention provides another embodiment of the axial aberration of a zoom lens at the wide-angle end. Axial aberration maps are one of the commonly used evaluation methods by optical designers. Figure 12This is an axial aberration diagram of the optical system at infinity at the wide-angle end. The vertical direction represents the normalized aperture, with 0 indicating the optical axis and the vertical vertex representing the maximum pupil radius. The horizontal direction represents the offset relative to the ideal focal point, in millimeters (mm). Different linear curves in the diagram represent different wavelengths of the system's imaging, derived from... Figure 12 It can be seen that the axial aberrations of the normalized apertures of different wavelengths (0-1.0) are all controlled within a reasonable range, indicating that the spherical aberration of the optical system is well controlled at each wavelength; it can meet the requirements of wide-spectrum applications.

[0081] Figure 13 This invention provides another ray fan diagram of a zoom lens at the wide-angle end, as part of an embodiment of the invention. Ray fan diagrams are one of the commonly used evaluation methods by optical designers. For example... Figure 13 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, 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 fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 13 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.

[0082] Figure 14 Another zoom lens with a vertical chromatic aberration curve at the telephoto end, provided as an embodiment of the present invention. Figure 14 This is the transverse chromatic aberration curve at infinity at the telephoto end of the optical system. The vertical axis represents the field of view, with 0 indicating the optical axis is on the line of sight. The vertex of the vertical axis represents the maximum image height. The dominant wavelength is 546 nm. The horizontal axis represents the offset relative to the dominant wavelength, in micrometers. ).Depend on Figure 14 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a small range, indicating that the transverse chromatic aberration of the zoom optical system is well controlled at the telephoto end, which can meet the application requirements under normal conditions.

[0083] Figure 15 This invention provides another example of an axial aberration map for a zoom lens at the telephoto end. Axial aberration maps are one of the commonly used evaluation methods by optical designers. Figure 15This is an axial aberration diagram of the optical system at infinity at the telephoto end. The vertical direction represents the normalized aperture, with 0 indicating on the optical axis, and the vertical vertex representing the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focal point, in millimeters (mm). Different linear curves in the diagram represent different wavelengths of the system's imaging, derived from... Figure 15 It can be seen that the axial aberrations of the normalized apertures of different wavelengths (0-1.0) are all controlled within a reasonable range, indicating that the spherical aberration of the optical system is well controlled at each wavelength; it can meet the requirements of wide-spectrum applications.

[0084] Figure 16 This invention provides another ray fan plot for a zoom lens at the telephoto end, as part of an embodiment of the invention. Ray fan plots are one of the commonly used evaluation methods by optical designers. For example... Figure 16 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, 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 fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 16 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.

[0085] In yet another exemplary embodiment, Figure 17 This is a schematic diagram of the structure of another zoom lens at the wide-angle end provided in an embodiment of the present invention. Figure 18 Table 11 provides a schematic diagram of the structure of another zoom lens at the telephoto end, illustrating yet another feasible implementation method, as shown in the embodiments of the present invention. Figure 17 and Figure 18 The specific parameters of the zoom lens shown are as follows.

[0086] Table 11 Another parameter design for zoom lenses Table 12 shows the design parameters of a zoom lens, including lens surface type, radius of curvature, thickness, and materials, corresponding to Table 11.

[0087] Table 12 Another optical physical parameter design for zoom lenses In Table 12, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens L1, surface number 2 represents the image side of the first lens L1, and so on. "STO" represents the aperture stop of the zoom lens; IMA represents the image plane; the radius of curvature represents the curvature of the corresponding lens surface in mm, with a positive value indicating that the surface bends towards the image plane and a negative value indicating that the surface bends towards the object plane. "INF" indicates that the surface is flat and the radius of curvature is infinite; the thickness represents the axial distance between the current surface and the next surface in mm; the refractive index represents the ability of the material between the current surface and the next surface to deflect light, with a blank space indicating that the current position is air and the refractive index is 1; the Abbe number represents the ability of the material between the current surface and the next surface to disperse light, with a blank space indicating that the current position is air and the Abbe number is 1.

[0088] Table 13 shows the design parameters for the zoom interval at the wide-angle and telephoto ends of a zoom lens corresponding to Table 12.

[0089] Table 13: Another zoom interval design for the wide-angle and telephoto ends of zoom lenses. Table 14 shows the aspheric coefficient values ​​used in the current embodiment.

[0090] Table 14 Aspherical coefficients of another type of zoom lens The k values ​​in Table 14 represent the numerical values ​​of the best-fit conic coefficients for the aspheric surface. The conic coefficients of the aspheric surface can be defined using the following aspheric formula, but are not limited to the following representations: ; Where z is the axial sagitta in the Z direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature; and k is the fitted conic coefficient. , , , , , , These are the higher-order aspheric coefficients corresponding to the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders of aspheric surfaces. These can be combined to form higher-order terms for the corresponding aspherical surfaces.

[0091] Based on the above parameter design, Table 15 shows the lens parameters of the zoom lens implemented in this embodiment.

[0092] Table 15 Lens parameters for another type of zoom lens Figure 19 This invention provides another type of chromatic aberration curve for a zoom lens at the wide-angle end. Figure 19 This is the transverse chromatic aberration curve at infinity at the wide-angle end of the optical system; the vertical axis represents the field of view, 0 indicates on the optical axis, and the vertex of the vertical axis represents the maximum image height; the dominant wavelength is 546nm, and the horizontal axis represents the offset relative to the dominant wavelength, in micrometers. ).Depend on Figure 19 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a small range, indicating that the transverse chromatic aberration of the zoom optical system is well controlled at the wide-angle end, which can meet the application requirements under normal conditions.

[0093] Figure 20 This invention provides another embodiment of the axial aberration diagram for a zoom lens at the wide-angle end. Axial aberration diagrams are one of the commonly used evaluation methods by optical designers. Figure 20 This is an axial aberration diagram of the optical system at infinity at the wide-angle end. The vertical direction represents the normalized aperture, with 0 indicating the optical axis and the vertical vertex representing the maximum pupil radius. The horizontal direction represents the offset relative to the ideal focal point, in millimeters (mm). Different linear curves in the diagram represent different wavelengths of the system's imaging, derived from... Figure 20 It can be seen that the axial aberrations of the normalized apertures of different wavelengths (0-1.0) are all controlled within a reasonable range, indicating that the spherical aberration of the optical system is well controlled at each wavelength; it can meet the requirements of wide-spectrum applications.

[0094] Figure 21 This invention provides another example of a zoom lens's ray fan plot at the wide-angle end. Ray fan plots are a commonly used evaluation method by optical designers. For example... Figure 21 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, 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 fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 21 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.

[0095] Figure 22 This invention provides another type of vertical chromatic aberration curve for a zoom lens at the telephoto end. Figure 22This is the transverse chromatic aberration curve at infinity at the telephoto end of the optical system. The vertical axis represents the field of view, with 0 indicating the optical axis is on the line of sight. The vertex of the vertical axis represents the maximum image height. The dominant wavelength is 546 nm. The horizontal axis represents the offset relative to the dominant wavelength, in micrometers. ).Depend on Figure 22 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a small range, indicating that the transverse chromatic aberration of the zoom optical system is well controlled at the telephoto end, which can meet the application requirements under normal conditions.

[0096] Figure 23 This invention provides another example of an axial aberration diagram for a zoom lens at the telephoto end. Axial aberration diagrams are one of the commonly used evaluation methods by optical designers. Figure 23 This is an axial aberration diagram of the optical system at infinity at the telephoto end. The vertical direction represents the normalized aperture, with 0 indicating on the optical axis, and the vertical vertex representing the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focal point, in millimeters (mm). Different linear curves in the diagram represent different wavelengths of the system's imaging, derived from... Figure 23 It can be seen that the axial aberrations of the normalized apertures of different wavelengths (0-1.0) are all controlled within a reasonable range, indicating that the spherical aberration of the optical system is well controlled at each wavelength; it can meet the requirements of wide-spectrum applications.

[0097] Figure 24 This invention provides another example of a zoom lens's ray fan plot at the telephoto end. Ray fan plots are a commonly used evaluation method by optical designers. For example... Figure 24 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, 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 fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 24 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.

[0098] Note that the above description is merely a preferred embodiment and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the appended claims.

Claims

1. A zoom lens, characterized in that, include: Along the optical axis, from the object side to the image side, are arranged the focusing lens group with negative optical power, the aperture, the zoom lens group with positive optical power, and the fixed lens group with negative optical power. The focusing lens group includes a first lens with negative optical power, a second lens with negative optical power, and a third lens with positive optical power; The zoom lens group includes a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power, and a ninth lens with either positive or negative optical power; wherein the optical power of the lens group formed by the seventh lens and the eighth lens is either negative or positive. The fixed lens group includes a tenth lens with negative optical power and an eleventh lens with positive optical power; The focusing lens group and the zoom lens group are moved along the direction of the optical axis; when the focusing lens group and the zoom lens group move together along the direction of the optical axis, the zoom lens can switch between the wide-angle end and the telephoto end.

2. The zoom lens according to claim 1, characterized in that, In the focusing lens group, the image-side surface of the first lens is concave, the object-side surface and the image-side surface of the second lens are both concave, the object-side surface of the third lens is convex, and the image-side surface of the third lens is concave. In the fixed lens group, the object-side surface of the tenth lens is convex, the image-side surface of the tenth lens is concave, the object-side surface of the eleventh lens is convex, and the image-side surface of the eleventh lens is concave.

3. The zoom lens according to claim 1, characterized in that, 2.200≤FT / FW≤2.250; Wherein, FT is the focal length of the zoom lens at the telephoto end, and FW is the focal length of the zoom lens at the wide-angle end.

4. The zoom lens according to claim 1, characterized in that, -2.809≤F1q / FW≤-2.343; 2.358≤F2q / FW≤2.519; -31.744≤F3q / FW≤-21.870; Wherein, F1q is the focal length of the focusing lens group, F2q is the focal length of the zoom lens group, F3q is the focal length of the fixed lens group, and FW is the focal length of the zoom lens at the wide-angle end.

5. The zoom lens according to claim 1, characterized in that, The fourth lens, the ninth lens, and the eleventh lens are all aspherical lenses.

6. The zoom lens according to claim 1, characterized in that, The fifth lens and the sixth lens form a cemented lens group, and the seventh lens and the eighth lens form a cemented lens group; 1.190≤F56 / F2q≤1.485; -3.294≤F78 / F2q≤4.464; Wherein, F56 is the focal length of the cemented lens group composed of the fifth lens and the sixth lens, F78 is the focal length of the cemented lens group composed of the seventh lens and the eighth lens, and F2q is the focal length of the zoom lens group.

7. The zoom lens according to claim 1, characterized in that, The fifth lens and the sixth lens form a cemented lens group, and the seventh lens and the eighth lens form a cemented lens group; 1.652≤nd5≤1.703; 48.080≤vd5≤58.403; 1.571≤nd6≤1.594; 60.475≤vd6≤71.616; 1.640≤nd7≤1.673; 32.171≤vd7≤34.465; 1.497≤nd8≤1.571; 71.616≤vd8≤81.608; Wherein, nd5 is the refractive index of the fifth lens, nd6 is the refractive index of the sixth lens, nd7 is the refractive index of the seventh lens, nd8 is the refractive index of the eighth lens, vd5 is the Abbe number of the fifth lens, vd6 is the Abbe number of the sixth lens, vd7 is the Abbe number of the seventh lens, and vd8 is the Abbe number of the eighth lens.

8. The zoom lens according to claim 1, characterized in that, 1.497≤nd1≤1.554;71.762≤vd1≤81.608; 1.500≤nd2≤1.550、66.021≤vd2≤75.225; 2.001≤nd3≤2.104;17.018≤vd3≤25.458; 1.497≤nd4≤1.528; 70.371≤vd4≤81.612; 1.821≤nd9≤1.884;37.199≤vd9≤42.706; 1.834≤nd11≤2.002; 20.700≤vd11≤37.285; Wherein, nd1 is the refractive index of the first lens, nd2 is the refractive index of the second lens, nd3 is the refractive index of the third lens, nd4 is the refractive index of the fourth lens, nd9 is the refractive index of the ninth lens, nd11 is the refractive index of the eleventh lens, vd1 is the Abbe number of the first lens, vd2 is the Abbe number of the second lens, vd3 is the Abbe number of the third lens, vd4 is the Abbe number of the fourth lens, vd9 is the Abbe number of the ninth lens, and vd11 is the Abbe number of the eleventh lens.

9. The zoom lens according to claim 1, characterized in that, 1.701≤S1 / S2≤2.366; Wherein, S1 is the maximum distance that the focusing lens group can move, and S2 is the maximum distance that the zoom lens group can move.

10. The zoom lens according to claim 1, characterized in that, 2.220≤TTL / ΦG1≤2.548 Wherein, TTL is the total length of the optical system of the zoom lens at the wide-angle end, and ΦG1 is the maximum lens diameter in the focusing lens group.

11. The zoom lens according to claim 1, characterized in that, 25.963≤TTL / M≤29.096; Wherein, TTL is the total length of the optical system of the zoom lens at the wide-angle end, and M is the zoom ratio of the zoom lens.

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