A zoom lens and an imaging system

Abstract

The application discloses a zoom lens and an imaging system. The zoom lens comprises a first group, a second group and a third group arranged in sequence along an optical axis from an object plane to an image plane. The first group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens. The second group comprises a sixth lens, a seventh lens, an eighth lens and a ninth lens. The third group comprises a tenth lens, an eleventh lens, a twelfth lens and a thirteenth lens. The first lens, the third lens, the sixth lens, the seventh lens, the ninth lens, the eleventh lens, the twelfth lens and the thirteenth lens are positive focal length lenses. The second lens, the fourth lens, the fifth lens, the eighth lens and the tenth lens are negative focal length lenses. By reasonably setting the number of lenses in the optical system and the focal length matching mode, the imaging effect of the optical system can be improved, and a high-definition zoom effect can be realized.

Description

Technical Field

[0001] The present invention relates to the field of optical device technology, and in particular to a teleconverter lens and an imaging system. Background Technology

[0002] External lenses for mobile phones, especially teleconverters, allow users to clearly capture distant stage details at events such as concerts, bringing new possibilities to mobile photography.

[0003] Currently, there are three main directions for such products: professional models, affordable universal models, and modular lens systems. For consumers, professional models are always the first choice, offering sharp, clear images with excellent quality, dedicated accessories for stable connection and image stabilization, and good compatibility and user experience, making them the most popular choice. Affordable universal models, while cheaper, tend to produce darker images with color cast, resulting in a far inferior user experience compared to professional models. Modular lens systems, on the other hand, are still in the conceptual stage and have poor portability.

[0004] Currently, there are still shortcomings in the market for external detachable lenses that can be installed on the built-in camera of mobile phones to improve the image quality of mobile phones, and they still cannot meet the needs of users. Summary of the Invention

[0005] This invention provides a teleconverter lens that achieves both small size and high image quality by rationally setting the number and combination of lenses, as well as the optical power matching between different lenses.

[0006] In a first aspect, embodiments of the present invention provide a teleconverter lens, comprising a first group, a second group, and a third group arranged sequentially along the optical axis from the object plane to the image plane;

[0007] The first group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; the second group includes a sixth lens, a seventh lens, an eighth lens, and a ninth lens; and the third group includes a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens.

[0008] The first lens, the third lens, the sixth lens, the seventh lens, the ninth lens, the eleventh lens, the twelfth lens, and the thirteenth lens are all positive power lenses; the second lens, the fourth lens, the fifth lens, the eighth lens, and the tenth lens are negative power lenses.

[0009] Optionally, the optical power of the first group is ΦZ1, the optical power of the second group is ΦZ2, and the optical power of the third group is ΦZ3;

[0010] Among them, 0.0027mm -1≤ΦZ1≤0.0033mm -1 0.0268mm -1 ≤ΦZ2≤0.0278mm -1 0.0470mm -1 ≤ΦZ3≤0.0489mm -1 .

[0011] Optionally, the combined optical power of the first lens and the second lens is Φ1-2, the combined optical power of the third lens and the fourth lens is Φ3-4, the optical power of the fifth lens is Φ5, the optical power of the sixth lens is Φ6, the combined optical power of the seventh lens and the eighth lens is Φ7-8, the optical power of the ninth lens is Φ9, the combined optical power of the tenth lens and the eleventh lens is Φ10-11, the optical power of the twelfth lens is Φ12, and the optical power of the thirteenth lens is Φ13.

[0012] Among them, 0.0308mm -1 ≤Φ1-2≤0.0309mm -1 -0.0441mm -1 ≤Φ3-4≤-0.0438mm -1 -0.0043mm -1 ≤Φ5≤-0.0030mm -1 0.0390mm -1 ≤Φ6≤0.0395mm -1 -0.0441mm -1 ≤Φ7-8≤-0.0409mm -1 0.0021mm -1 ≤Φ9≤0.0040mm -1 0.0073mm -1 ≤Φ10-11≤0.0143mm -1 0.0215mm -1 ≤Φ12≤0.0245mm -1 0.0205mm -1 ≤Φ13≤0.0221mm -1 .

[0013] Optionally, the optical power of the second group is ΦZ2, the combined optical power of the tenth lens, the eleventh lens and the twelfth lens is Φ10-12, and the maximum optical distortion of the teleconverter is DISG.MAX;

[0014] Among them, 0.7792≤ΦZ2 / Φ10-12≤0.9433, 0≤|DISG.MAX|≤1.0549%.

[0015] Optionally, the minimum refractive index of the second lens, the fourth lens, the fifth lens, the eighth lens, and the tenth lens is ND_D;

[0016] Wherein, 1.9111≤ND_D≤1.9113.

[0017] Optionally, the first lens and the second lens are cemented together, the third lens and the fourth lens are cemented together, the seventh lens and the eighth lens are cemented together, and the tenth lens and the eleventh lens are cemented together.

[0018] Optionally, the Abbe number of the first lens is VD1, the Abbe number of the second lens is VD2, the Abbe number of the third lens is VD3, the Abbe number of the fourth lens is VD4, the Abbe number of the tenth lens is VD10, and the Abbe number of the eleventh lens is VD11.

[0019] Among them, 2.0145≤VD1 / VD2≤2.1399; 3.3937≤VD3 / VD4≤3.3939; 5.2779≤VD11 / VD10≤5.2879.

[0020] Optionally, the teleconverter has an optical length of TTL, a focal length of EFL, a maximum effective aperture of DM, a field of view of FOV, and a magnification of PMAG.

[0021] Among them, 1.9969≤TTL / EFL≤2.0620; 4.3429≤TTL / DM≤4.4828; 12.3965°≤FOV≤12.4195°; 2.3114≤PMAG≤2.3130.

[0022] Optionally, the first lens includes a first object-side surface near the object surface and a first image-side surface near the image surface, wherein the first object-side surface is convex and the first image-side surface is convex.

[0023] The second lens includes a second object-side surface near the object plane and a second image-side surface near the image plane. The second object-side surface is concave, and the second image-side surface is convex.

[0024] The third lens includes a third object-side surface near the object plane and a third image-side surface near the image plane. The third object-side surface is convex, and the third image-side surface is convex.

[0025] The fourth lens includes a fourth object-side surface near the object plane and a fourth image-side surface near the image plane. The fourth object-side surface is concave, and the fourth image-side surface is concave.

[0026] The fifth lens includes a fifth object-side surface near the object plane and a fifth image-side surface near the image plane. The fifth object-side surface is concave, and the fifth image-side surface is convex.

[0027] The sixth lens includes a sixth object-side surface near the object plane and a sixth image-side surface near the image plane. The sixth object-side surface is convex, and the sixth image-side surface is convex.

[0028] The seventh lens includes a seventh object-side surface near the object plane and a seventh image-side surface near the image plane. The seventh object-side surface is convex, and the seventh image-side surface is convex.

[0029] The eighth lens includes an eighth object-side surface near the object plane and an eighth image-side surface near the image plane. The eighth object-side surface is concave, and the eighth image-side surface is concave.

[0030] The ninth lens includes a ninth object-side surface near the object plane and a ninth image-side surface near the image plane. The ninth object-side surface is concave, and the ninth image-side surface is convex.

[0031] The tenth lens includes a tenth object-side surface near the object plane and a tenth image-side surface near the image plane. The tenth object-side surface is either concave or flat, and the tenth image-side surface is concave.

[0032] The eleventh lens includes an eleventh object-side surface near the object plane and an eleventh image-side surface near the image plane. The eleventh object-side surface is convex, and the eleventh image-side surface is convex.

[0033] The twelfth lens includes a twelfth object-side surface near the object plane and a twelfth image-side surface near the image plane. The twelfth object-side surface is convex, flat, or concave, and the twelfth image-side surface is convex.

[0034] The thirteenth lens includes a thirteenth object-side surface near the object plane and a thirteenth image-side surface near the image plane. The thirteenth object-side surface is convex, and the thirteenth image-side surface is convex.

[0035] Optionally, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens, and the thirteenth lens are all glass spherical lenses.

[0036] Optionally, the teleconverter lens may further include an aperture stop, which is disposed on the image side of the thirteenth lens.

[0037] In a second aspect, embodiments of the present invention also provide an imaging system, including the teleconverter lens described in the first aspect;

[0038] The imaging system also includes an imaging lens, which is located on the light-emitting side of the teleconverter lens.

[0039] The teleconverter lens provided in this embodiment of the invention ensures good imaging effect and magnification effect of the optical system by reasonably setting the number of lens groups included in the lens, the number of lenses included in each lens group, and the optical power matching method of each lens.

[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 this application, the accompanying drawings used in the description of the embodiments of this application 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 the content of the embodiments of this application and these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the structure of a teleconverter lens at infinity object distance provided in Embodiment 1 of the present invention;

[0043] Figure 2 This is a schematic diagram of the light fan of a teleconverter lens at infinity object distance, provided in Embodiment 1 of the present invention:

[0044] Figure 3 This is a schematic diagram of field curvature distortion of a teleconverter lens at infinity object distance, provided in Embodiment 1 of the present invention:

[0045] Figure 4 This is an MTF curve of a teleconverter lens at infinity object distance provided in Embodiment 1 of the present invention:

[0046] Figure 5 Here is an MTF curve of a teleconverter lens at an object distance of 1m, provided in Embodiment 1 of the present invention:

[0047] Figure 6 This is a schematic diagram of the structure of a teleconverter lens at infinity object distance provided in Embodiment 2 of the present invention;

[0048] Figure 7 This is a schematic diagram of the light beam fan of a teleconverter lens at infinity object distance, provided in Embodiment 2 of the present invention:

[0049] Figure 8 This is a schematic diagram of field curvature distortion of a teleconverter lens at infinity object distance, provided in Embodiment 2 of the present invention:

[0050] Figure 9 This is an MTF curve of a teleconverter lens at infinity object distance provided in Embodiment 2 of the present invention:

[0051] Figure 10 Here is an MTF curve of a teleconverter lens at an object distance of 1m, provided in Embodiment 2 of the present invention:

[0052] Figure 11 This is a schematic diagram of the structure of a teleconverter lens at infinity object distance provided in Embodiment 3 of the present invention;

[0053] Figure 12 This is a schematic diagram of the light fan of a teleconverter lens at infinity object distance, provided in Embodiment 3 of the present invention:

[0054] Figure 13 This is a schematic diagram of field curvature distortion of a teleconverter lens at infinity object distance, provided in Embodiment 3 of the present invention:

[0055] Figure 14 This is an MTF curve of a teleconverter lens at infinity object distance provided in Embodiment 3 of the present invention:

[0056] Figure 15 This is an MTF curve of a teleconverter lens at an object distance of 1m, provided in Embodiment 3 of the present invention. Detailed Implementation

[0057] 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.

[0058] Example 1

[0059] Figure 1 This is a schematic diagram of the structure of a teleconverter lens provided in Embodiment 1 of the present invention, as shown below. Figure 1As shown, the teleconverter lens provided in Embodiment 1 of the present invention includes a first group S1, a second group S2, and a third group S3 arranged sequentially along the optical axis from the object plane to the image plane; the first group S1 includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, and a fifth lens 105; the second group S2 includes a sixth lens 106, a seventh lens 107, an eighth lens 108, and a ninth lens 109; the third group S3 includes a tenth lens 110, an eleventh lens 111, a twelfth lens 112, and a thirteenth lens 113; wherein, the first lens 101, the third lens 103, the sixth lens 106, the seventh lens 107, the ninth lens 109, the eleventh lens 111, the twelfth lens 112, and the thirteenth lens 113 are all positive power lenses; the second lens 102, the fourth lens 104, the fifth lens 105, the eighth lens 108, and the tenth lens 110 are negative power lenses.

[0060] Specifically, the teleconverter lens provided in this embodiment of the invention includes a first group S1, a second group S2, and a third group S3 arranged along the optical axis. Further, the first group S1 includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, and a fifth lens 105; the second group S2 includes a sixth lens 106, a seventh lens 107, an eighth lens 108, and a ninth lens 109; and the third group S3 includes a tenth lens 110, an eleventh lens 111, a twelfth lens 112, and a thirteenth lens 113. In other words, the teleconverter lens contains a total of thirteen lenses with optical power. By rationally setting the lens combinations in the first group S1, the second group S2, and the third group S3, the number of lenses in the optical system is ensured to be reasonable. Too many lenses will result in a large optical system size, while too few lenses will cause large aberrations due to a single lens bearing a large focal length. This ensures both miniaturization of the optical system and low imaging aberrations, resulting in high image quality.

[0061] Furthermore, focal length is a measure of the convergence or divergence of light in an optical system; it refers to the distance from the optical center of the lens to the focal point where parallel light converges when incident. The larger the absolute value of the focal length, the weaker the bending ability of light; the smaller the absolute value of the focal length, the stronger the bending ability of light. When the focal length is positive, the refraction of light is converging; when the focal length is negative, the refraction of light is diverging. Focal length can be used to characterize a single refractive surface of a lens (i.e., a surface of the lens), a single lens, or a system formed by multiple lenses (i.e., a lens group). In this embodiment of the invention, the first lens 101 is a positive optical power lens, whose positive optical power setting can significantly correct the edge aberrations of the optical imaging system, thereby improving the imaging resolution of the optical system. The second lens 102 is a negative optical power lens, whose negative optical power setting can effectively deflect the outgoing light, which is beneficial for achieving a large image plane design. Furthermore, the third lens 103 is a positive power lens, the fourth lens 104 and the fifth lens 105 are both negative power lenses, the sixth lens 106 and the seventh lens 107 are both positive power lenses, the eighth lens 108 is a negative power lens, the ninth lens 109 is a positive power lens, the tenth lens 110 is a negative power lens, and the eleventh lens 111, the twelfth lens 112 and the thirteenth lens 113 are all positive power lenses. The lenses or lens groups with positive and negative power are alternately arranged, so that the lenses with positive and negative power can complement each other, balance the defects of the optical system, optimize imaging performance, such as correcting spherical aberration, chromatic aberration and distortion, and control the system length, so as to realize the miniaturized design of the optical system.

[0062] In summary, the teleconverter lens provided in this embodiment of the invention ensures good imaging and magnification effects of the optical system by reasonably setting the number of lens groups included in the lens, the number of lenses included in each lens group, and the optical power matching method of each lens.

[0063] Based on the above embodiments, the optical power of the first group S1 is ΦZ1, the optical power of the second group S2 is ΦZ2, and the optical power of the third group S3 is ΦZ3; wherein, 0.0027mm -1 ≤ΦZ1≤0.0033mm -1 0.0268mm -1 ≤ΦZ2≤0.0278mm -1 0.0470mm -1 ≤ΦZ3≤0.0489mm -1 By appropriately combining different groups of optical power, off-axis aberrations and chromatic aberrations can be effectively corrected, ensuring that the original image's clarity and color contrast are maintained to the maximum extent while achieving 2.3x magnification when paired with a mobile phone lens.

[0064] Based on the above embodiments, the combined optical power of the first lens 101 and the second lens 102 is Φ1-2, the combined optical power of the third lens and the fourth lens is Φ3-4, the optical power of the fifth lens is Φ5, the optical power of the sixth lens is Φ6, the combined optical power of the seventh lens and the eighth lens is Φ7-8, the optical power of the ninth lens is Φ9, the combined optical power of the tenth lens and the eleventh lens is Φ10-11, the optical power of the twelfth lens is Φ12, and the optical power of the thirteenth lens is Φ13; wherein, 0.0308mm -1 ≤Φ1-2≤0.0309mm -1 -0.0441mm -1 ≤Φ3-4≤-0.0438mm -1 -0.0043mm -1 ≤Φ5≤-0.0030mm -1 0.0390mm -1 ≤Φ6≤0.0395mm -1 -0.0441mm -1 ≤Φ7-8≤-0.0409mm -1 0.0021mm -1 ≤Φ9≤0.0040mm -1 0.0073mm -1 ≤Φ10-11≤0.0143mm -1 0.0215mm -1 ≤Φ12≤0.0245mm -1 0.0205mm -1 ≤Φ13≤0.0221mm -1 By properly matching the optical power of lenses or lens groups, off-axis aberrations and chromatic aberrations can be further corrected, while ensuring magnification and image display quality.

[0065] Based on the above embodiments, the optical power of the second group S2 is ΦZ2, the combined optical power of the tenth lens 110, the eleventh lens 111 and the twelfth lens 112 is Φ10-12, and the maximum optical distortion of the teleconverter is DISG.MAX; wherein, 0.7792≤ΦZ2 / Φ10-12≤0.9433, 0≤|DISG.MAX|≤1.0549%.

[0066] Specifically, the lens group formed by the second group S2 and the tenth lens 110, eleventh lens 111, and twelfth lens 112 is positioned before and after the first image in the optical system. The difference in optical power between the two groups is small, resulting in a relatively symmetrical structure. When the optical power of the lens group formed by the second group S2 and the tenth lens 110, eleventh lens 111, and twelfth lens 112 meets the above conditions, it can effectively correct the optical distortion of the system, reduce the impact of imaging distortion, and keep the maximum optical distortion of the system within ±1.06%, better reflecting the actual value of the photographed object and providing users with a better user experience.

[0067] Based on the above embodiments, the minimum refractive index of the second lens 102, the fourth lens 104, the fifth lens 105, the eighth lens 108, and the tenth lens 110 is ND_D; wherein, 1.9111≤ND_D≤1.9113.

[0068] Specifically, the second lens 102, the fourth lens 104, the fifth lens 105, the eighth lens 108, and the tenth lens 110 are all negative optical power lenses. Negative lenses play a crucial role in telephoto systems. The combination of all high-refractive-index negative lenses can maximize the magnification, ensure image quality, effectively control lens thickness, reduce lens weight, make the lens lightweight, and reduce the burden when attached to a mobile phone.

[0069] Based on the above embodiments, the first lens 101 and the second lens 102 are cemented together, the third lens 103 and the fourth lens 104 are cemented together, the seventh lens 107 and the eighth lens 108 are cemented together, and the tenth lens 110 and the eleventh lens 111 are cemented together.

[0070] Specifically, different lens cementation settings can be understood as the image-side surface of the preceding lens and the object-side surface of the following lens being fitted together in the optical path, possessing the same surface shape. For example... Figure 1 As shown, the first lens 101 and the second lens 102 are cemented together, which can be understood as the image-side of the first lens 101 and the object-side of the second lens 102 being bonded together to form two bonded lenses; the third lens 103 and the fourth lens 104 are cemented together, which can be understood as the image-side of the third lens 103 and the object-side of the fourth lens 104 being bonded together to form two bonded lenses; the seventh lens 107 and the eighth lens 108 are cemented together, which can be understood as the image-side of the seventh lens 107 and the object-side of the eighth lens 108 being bonded together to form two bonded lenses; the tenth lens 110 and the eleventh lens 111 are cemented together, which can be understood as the image-side of the tenth lens 110 and the object-side of the eleventh lens 111 being bonded together to form two bonded lenses.

[0071] Furthermore, cemented lenses can be used to minimize or eliminate chromatic aberration. Using cemented lenses in teleconverters improves image quality and reduces light energy reflection loss, thereby enhancing image sharpness. Additionally, the cementation process eliminates the air gap between the two lenses, resulting in a more compact optical system that meets miniaturization requirements. Moreover, the cementation reduces tolerance sensitivity issues such as tilting / eccentricity that occur during lens assembly.

[0072] Furthermore, the two lenses that are glued together can be supported by a gasket or glued together. The specific method of gluing is not limited in the embodiments of the present invention.

[0073] Based on the above embodiments, the Abbe number of the first lens 101 is VD1, the Abbe number of the second lens 102 is VD2, the Abbe number of the third lens 103 is VD3, the Abbe number of the fourth lens 104 is VD4, the Abbe number of the tenth lens 110 is VD10, and the Abbe number of the eleventh lens 111 is VD11; wherein, 2.0145≤VD1 / VD2≤2.1399;

[0074] 3.3937≤VD3 / VD4≤3.3939; 5.2779≤VD11 / VD10≤5.2879. All three pairs of lenses are cemented lenses. A positive and negative lens group meeting these conditions has a low-high Abbe number for the positive lens and a high-low Abbe number for the negative lens, with a significant difference between their Abbe numbers. This effectively corrects chromatic aberration and spherical aberration, improving image quality and making the captured image more realistic.

[0075] Based on the above embodiments, the teleconverter lens has an optical total length of TTL, a focal length of EFL, a maximum effective aperture of DM, a field of view of FOV, and a magnification of PMAG; wherein, 1.9969≤TTL / EFL≤2.0620; 4.3429≤TTL / DM≤4.4828; 12.3965°≤FOV≤12.4195°; 2.3114≤PMAG≤2.3130.

[0076] Specifically, in telephoto optical systems, to achieve a large aperture, the overall length and aperture are typically long. This invention fully utilizes the properties of high-refractive-index materials, satisfying the above-mentioned conditions to achieve a large aperture while reducing the size. Furthermore, this invention uses only thirteen lenses to achieve high-quality imaging in a large-aperture system, keeping the overall length within 108mm while minimizing weight and size, and ensuring clear resolution.

[0077] Based on the above embodiments, the first lens 101 includes a first object-side surface near the object plane and a first image-side surface near the image plane, both of which are convex; the second lens 102 includes a second object-side surface near the object plane and a second image-side surface near the image plane, both of which are concave; the third lens 103 includes a third object-side surface near the object plane and a third image-side surface near the image plane, both of which are convex; the fourth lens 104 includes a first object-side surface near the object plane and a third image-side surface near the image plane. The fourth object-side surface on the object plane side and the fourth image-side surface on the image plane side are both concave; the fifth lens 105 includes a fifth object-side surface on the object plane side and a fifth image-side surface on the image plane side, both concave and convex; the sixth lens 106 includes a sixth object-side surface on the object plane side and a sixth image-side surface on the image plane side, both convex and convex; the seventh lens 107 includes a seventh object-side surface on the object plane side and a seventh image-side surface on the image plane side. The seventh object-side surface is convex, and the seventh image-side surface is convex; the eighth lens 108 includes an eighth object-side surface near the object surface and an eighth image-side surface near the image surface, both of which are concave; the ninth lens 109 includes a ninth object-side surface near the object surface and a ninth image-side surface near the image surface, both of which are concave; the tenth lens 110 includes a tenth object-side surface near the object surface and a tenth image-side surface near the image surface, both of which are concave or planar, and both are concave. The eleventh lens 111 includes an eleventh object-side surface near the object plane and an eleventh image-side surface near the image plane. The eleventh object-side surface and the eleventh image-side surface are both convex. The twelfth lens 112 includes a twelfth object-side surface near the object plane and a twelfth image-side surface near the image plane. The twelfth object-side surface is convex, flat, or concave, and the twelfth image-side surface is convex. The thirteenth lens 113 includes a thirteenth object-side surface near the object plane and a thirteenth image-side surface near the image plane. The thirteenth object-side surface and the thirteenth image-side surface are both convex.

[0078] Specifically, the object-side surface of a lens can be understood as the surface of the lens closest to the object plane, and the image-side surface of a lens can be understood as the surface of the lens closest to the image plane.

[0079] The object-side surface of the first lens 101 is convex, and the image-side surface is also convex. This can be understood as the object-side surface of the first lens 101 convex towards the object surface near the optical axis, and the image-side surface convex towards the image surface near the optical axis. In other words, the first lens 101 is a lens with a biconvex structure.

[0080] The object-side surface of the second lens 102 is concave, and the image-side surface is convex. This can be understood as the object-side surface of the second lens 102 being concave towards the object plane near the optical axis, and the image-side surface being convex towards the image plane near the optical axis. In other words, the second lens 102 is a lens with a concave-convex structure. Furthermore, the concave object-side surface of the second lens 102 can be combined with the convex image-side surface of the first lens 101, facilitating the cemented bonding of the second lens 102 and the first lens 101.

[0081] The object-side surface of the third lens 103 is convex, and the image-side surface is also convex. This can be understood as the object-side surface of the third lens 103 convex towards the object surface near the optical axis, and the image-side surface convex towards the image surface near the optical axis. In other words, the third lens 103 is a lens with a biconvex structure.

[0082] The object-side surface of the fourth lens 104 is concave, and the image-side surface is also concave. This can be understood as the object-side surface of the fourth lens 104 being concave towards the object plane near the optical axis, and the image-side surface being concave towards the image plane near the optical axis. In other words, the fourth lens 104 is a double-concave lens. Furthermore, the concave object-side surface of the fourth lens 104 can be combined with the convex image-side surface of the third lens 101, facilitating the cemented bonding of the fourth lens 104 and the third lens 103.

[0083] The object side of the fifth lens 105 is concave, and the image side is convex. This can be understood as the object side of the fifth lens 105 being concave towards the object surface near the optical axis, and the image side being convex towards the image surface near the optical axis. In other words, the fifth lens 105 has a concave-convex structure.

[0084] The object-side surface of the sixth lens 106 is convex, and the image-side surface is also convex. This can be understood as the object-side surface of the sixth lens 106 convex towards the object surface near the optical axis, and the image-side surface convex towards the image surface near the optical axis. In other words, the sixth lens 106 can be a lens with a biconvex structure.

[0085] The object-side surface of the seventh lens 107 is convex, and the image-side surface is also convex. This can be understood as the object-side surface of the seventh lens 107 convex towards the object surface near the optical axis, and the image-side surface convex towards the image surface near the optical axis. In other words, the seventh lens 107 can be a lens with a biconvex structure.

[0086] The object-side surface of the eighth lens 108 is concave, and the image-side surface is also concave. This can be understood as the object-side surface of the eighth lens 108 being concave towards the object plane near the optical axis, and the image-side surface being concave towards the image plane near the optical axis. In other words, the eighth lens 108 is a double-concave lens. Furthermore, the concave object-side surface of the eighth lens 108 can be combined with the convex image-side surface of the seventh lens 107, facilitating the cemented bonding of the eighth lens 108 and the seventh lens 107.

[0087] The object-side surface of the ninth lens 109 is concave, and the image-side surface is convex. This can be understood as the object-side surface of the ninth lens 109 being concave towards the object surface near the optical axis, and the image-side surface being convex towards the image surface near the optical axis. In other words, the ninth lens 109 can be a lens with a concave-convex structure.

[0088] The object side of the tenth lens 110 is concave or flat, and the image side is concave. This can be understood as the object side of the tenth lens 110 being concave or flat near the optical axis and the image side being concave near the image axis. In other words, the tenth lens 110 is a lens with a double concave structure or a plano-concave structure.

[0089] The object-side surface of the eleventh lens 111 is convex, and the image-side surface is also convex. This can be understood as the object-side surface of the eleventh lens 111 bulging towards the object plane near the optical axis, and the image-side surface bulging towards the image plane near the optical axis. In other words, the eleventh lens 111 can be a biconvex lens. Furthermore, the convex object-side surface of the eleventh lens 111 can be combined with the concave image-side surface of the tenth lens 110, facilitating the cemented bonding of the eleventh lens 111 and the tenth lens 110.

[0090] The object side of the twelfth lens 112 is convex, flat, or concave, and the image side is convex. This can be understood as the object side of the twelfth lens 112 being convex, concave, or flat towards the object surface near the optical axis, and the image side being convex towards the image surface near the optical axis. In other words, the twelfth lens 112 is a lens with a biconvex structure, a plano-convex structure, or a concave-convex structure.

[0091] The object-side surface of the thirteenth lens 113 is convex, and the image-side surface is also convex. This can be understood as the object-side surface of the thirteenth lens 113 convex towards the object plane near the optical axis, and the image-side surface convex towards the image plane near the optical axis. In other words, the thirteenth lens 113 is a lens with a biconvex structure.

[0092] By properly setting the concave and convex surfaces of each lens, the light emission angle of each lens can be modulated. Furthermore, for cemented lenses, it is possible to cement at least two adjacent lenses together. On the other hand, it can also reduce the spacing between adjacent lenses, which is beneficial for designing a small-volume teleconverter lens.

[0093] Based on the above embodiments, the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, the seventh lens 107, the eighth lens 108, the ninth lens 109, the tenth lens 110, the eleventh lens 111, the twelfth lens 112, and the thirteenth lens 113 are all glass spherical lenses.

[0094] Specifically, spherical lenses are characterized by a constant curvature from the center to the periphery, ensuring a simple lens setup. Furthermore, due to the low coefficient of thermal expansion and good stability of glass lenses, all lenses from the first lens 101 to the twelfth lens 112 are glass spherical lenses. The thermal properties of glass spherical lenses are more stable, ensuring good resolving power over a wide temperature range when handling higher optical powers. Moreover, the range of glass materials available is wider, and the choice of refractive index and Abbe number is relatively flexible, allowing for better control of higher aberrations and chromatic aberration, meeting the needs of use under complex conditions.

[0095] Based on the above embodiments, the teleconverter lens also includes an aperture stop (not shown in the figure), which is disposed on the image-side side of the thirteenth lens 113. The aperture stop can adjust the propagation direction of the light beam, which is beneficial for improving image quality.

[0096] Based on the same inventive communication, embodiments of the present invention also provide an imaging system, including the teleconverter lens provided in the above embodiments, and an imaging lens, the imaging lens being located on the light-emitting side of the teleconverter lens. Furthermore, the teleconverter lens and the imaging lens, used in conjunction, can increase the imaging magnification of the imaging system, achieving a high magnification imaging system.

[0097] As one feasible implementation method, the teleconverter lens and imaging system will be described below.

[0098] Table 1. Optical design values ​​for the teleconverter lens in Example 1

[0099]

[0100] Table 2 Design values ​​of optical physical parameters for teleconverter lenses

[0101]

[0102] The surface numbers in Table 2 are assigned according to the surface sequence of each lens; the radius of curvature represents the degree of curvature of the lens surface, with positive values ​​indicating that the surface bends towards the image plane and negative values ​​indicating that the surface bends towards the object plane; the thickness represents the central axial distance between the current surface and the next surface; the refractive index represents the ability of the material between the current surface and the next surface to deflect light; a blank space indicates that the current position is air with a refractive index of 1; the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface. Half-aperture indicates half the aperture size of the current surface. The 23rd surface has a spacing of 25.582 mm, allowing focusing to an object distance of 1 m.

[0103] Furthermore, Figure 2This is a schematic diagram of the light fan of a teleconverter lens at infinity object distance, provided in Embodiment 1 of the present invention. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis represents the beam aperture, and the vertical axis represents the transverse aberration. The ideal curve is a straight line coinciding with the horizontal axis, indicating that all light rays converge at the same point on the image plane. The interval corresponding to the vertical axis of the curve is the maximum dispersion range of the beam on the ideal image plane. The light fan diagram can reflect not only monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 2 It can be seen that the system closely approximates the horizontal axis at all wavelengths (435nm, 470nm, 510nm, 555nm, 610nm and 650nm) in all fields of view, indicating that the vertical aberration of each wavelength is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the system is also well corrected, thus ensuring that the optical system can achieve the high-resolution imaging requirements.

[0104] Figure 3 This is a schematic diagram of field curvature distortion of a teleconverter lens at infinity object distance, provided in Embodiment 1 of the present invention. In the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; Figure 3 It can be seen that the lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small, resulting in good consistency; in the coordinate system on the right, the horizontal coordinate represents the magnitude of distortion, expressed as a percentage, while the vertical coordinate represents the normalized image height, which has no unit; from Figure 3 As can be seen, the distortion of the lens provided in this embodiment has been well corrected, with optical distortion less than ±1.06%.

[0105] Figure 4 This is an MTF curve of a teleconverter lens at infinity, provided in Embodiment 1 of the present invention. The MTF curve represents the resolving power of the optical system for an object at different frequencies in different fields of view, meridional, and sagittal directions. It reflects the image quality of the object after passing through the optical system. The ideal curve represents the diffraction limit at the highest point, indicating the physical limits of the lens under this parameter. The vertical axis of the curve corresponds to the contrast ratio of the black and white line boundaries (M' / M), where M refers to the grating modulation degree before imaging, and M' refers to the grating modulation degree after imaging; therefore, 0 ≤ M' / M ≤ 1. The horizontal axis corresponds to the number of black and white lines within 1 mm. S and T correspond to the sagittal and meridional directions of each field of view. Figure 4 As shown, the image quality of the lens of the present invention is higher than 0.2 MTF from the center field of view to the edge field of view, with a resolution of 223 pl / mm.

[0106] Figure 5This is an MTF curve of a teleconverter lens provided in Embodiment 1 of the present invention at an object distance of 1m. The MTF curve represents the resolving power of the optical system for an object at different frequencies in different fields of view, meridional, and sagittal directions. It reflects the imaging quality of the object after passing through the optical system. The ideal curve is the diffraction limit at the highest point, indicating the physical limit of the lens under this parameter. The vertical axis of the curve corresponds to the contrast ratio of black and white line boundaries (M' / M), where M refers to the grating modulation degree before imaging, and M' refers to the grating modulation degree after imaging. Therefore, 0≤M' / M≤1. The horizontal axis corresponds to the number of black and white lines within 1mm. S and T correspond to the sagittal and meridional directions of each field of view. Figure 5 As shown, the image quality of the lens of the present invention is higher than 0.2 MTF from the center field of view to the edge field of view, with a resolution of 223 pl / mm.

[0107] In summary, the teleconverter lens provided in this embodiment of the invention employs a structure with 13 glass spherical lenses. Through the combination of lens materials and the rational allocation of the optical power of each element, it is adapted to a mobile phone lens with a focal length of 22.48mm, achieving a 2.3x high-definition magnification effect. High resolution can be achieved at focusing distances from 1m to infinity. At infinity, it can maintain low distortion and high-resolution shooting with a large aperture. The overall system focal length is 52mm, the maximum aperture is F2.5, the maximum optical distortion is <1.06%, and the image quality can reach 223pl / mm>0.2MTF. Furthermore, the distance from the front end of the first lens to the rear end of the last lens is less than 108mm, the maximum effective diameter of the lens is less than 24mm, and the maximum target surface can support Φ11.44mm.

[0108] Example 2

[0109] Figure 6 This is a schematic diagram of the structure of a teleconverter lens provided in Embodiment 2 of the present invention, as shown below. Figure 6 As shown, the teleconverter lens provided in Embodiment 2 of the present invention includes a first group S1, a second group S2, and a third group S3 arranged sequentially along the optical axis from the object plane to the image plane; the first group S1 includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, and a fifth lens 105; the second group S2 includes a sixth lens 106, a seventh lens 107, an eighth lens 108, and a ninth lens 109; the third group S3 includes a tenth lens 110, an eleventh lens 111, a twelfth lens 112, and a thirteenth lens 113; wherein, the first lens 101, the third lens 103, the sixth lens 106, the seventh lens 107, the ninth lens 109, the eleventh lens 111, the twelfth lens 112, and the thirteenth lens 113 are all positive power lenses; the second lens 102, the fourth lens 104, the fifth lens 105, the eighth lens 108, and the tenth lens 110 are negative power lenses.

[0110] Other parameters are the same as in Example 1, and will not be repeated here.

[0111] As another feasible implementation method, the specific parameters of the teleconverter lens are explained below.

[0112] Table 3. Optical design values ​​for the teleconverter lens in Example 2

[0113]

[0114] Table 4 Design values ​​of optical physical parameters for teleconverter lenses

[0115]

[0116] The surface numbers in Table 4 are assigned according to the surface sequence of each lens; the radius of curvature represents the degree of curvature of the lens surface, with positive values ​​indicating that the surface bends towards the image plane and negative values ​​indicating that the surface bends towards the object plane; the thickness represents the central axial distance between the current surface and the next surface; the refractive index represents the ability of the material between the current surface and the next surface to deflect light; a blank space indicates that the current position is air with a refractive index of 1; the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface. Half-aperture indicates half the aperture size of the current surface. The 23rd surface has a spacing of 25.939 mm, allowing focusing to an object distance of 1 m.

[0117] Furthermore, Figure 7 This is a schematic diagram of the light fan of a teleconverter lens at infinity object distance, provided in Embodiment 2 of the present invention. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis represents the beam aperture, and the vertical axis represents the transverse aberration. The ideal curve is a straight line coinciding with the horizontal axis, indicating that all light rays converge at the same point on the image plane. The interval corresponding to the vertical axis of the curve is the maximum dispersion range of the beam on the ideal image plane. The light fan diagram can reflect not only monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 7 It can be seen that the system closely approximates the horizontal axis at all wavelengths (435nm, 470nm, 510nm, 555nm, 610nm and 650nm) in all fields of view, indicating that the vertical aberration of each wavelength is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the system is also well corrected, thus ensuring that the optical system can achieve the high-resolution imaging requirements.

[0118] Figure 8 This is a schematic diagram of field curvature distortion of a teleconverter lens at infinity object distance, provided in Embodiment 2 of the present invention. In the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; Figure 8It can be seen that the lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small, resulting in good consistency; in the coordinate system on the right, the horizontal coordinate represents the magnitude of distortion, expressed as a percentage, while the vertical coordinate represents the normalized image height, which has no unit; from Figure 8 As can be seen, the distortion of the lens provided in this embodiment has been well corrected, with optical distortion less than ±1.06%.

[0119] Figure 9 This is an MTF curve of a teleconverter lens at infinity, provided in Embodiment 2 of the present invention. The MTF curve represents the resolving power of the optical system for an object at different frequencies in different fields of view, meridional, and sagittal directions. It reflects the imaging quality of the object after passing through the optical system. The ideal curve is the diffraction limit at the highest point, indicating the physical limit of the lens under this parameter. The vertical axis of the curve corresponds to the contrast ratio of black and white line boundaries (M' / M), where M refers to the grating modulation degree before imaging, and M' refers to the grating modulation degree after imaging; therefore, 0 ≤ M' / M ≤ 1. The horizontal axis corresponds to the number of black and white lines within 1 mm. S and T correspond to the sagittal and meridional directions of each field of view. Figure 9 As shown, the image quality of the lens of the present invention is higher than 0.2 MTF from the center field of view to the edge field of view, with a resolution of 223 pl / mm.

[0120] Figure 10 This is an MTF curve of a teleconverter lens provided in Embodiment 2 of the present invention at an object distance of 1m. The MTF curve represents the resolving power of the optical system for an object at different frequencies in different fields of view, meridional, and sagittal directions. It reflects the imaging quality of the object after passing through the optical system. The ideal curve is the diffraction limit at the highest point, indicating the physical limit of the lens under this parameter. The vertical axis of the curve corresponds to the contrast ratio of black and white line boundaries (M' / M), where M refers to the grating modulation degree before imaging, and M' refers to the grating modulation degree after imaging. Therefore, 0≤M' / M≤1. The horizontal axis corresponds to the number of black and white lines within 1mm. S and T correspond to the sagittal and meridional directions of each field of view. Figure 10 As shown, the image quality of the lens of the present invention is higher than 0.2 MTF from the center field of view to the edge field of view, with a resolution of 223 pl / mm.

[0121] In summary, the teleconverter lens provided in this embodiment of the invention employs a structure with 13 glass spherical lenses. Through the combination of lens materials and the rational allocation of the optical power of each element, it is adapted to a mobile phone lens with a focal length of 22.48mm, achieving a 2.3x high-definition magnification effect. High resolution can be achieved at focusing distances from 1m to infinity. At infinity, it can maintain low distortion and high-resolution shooting with a large aperture. The overall system focal length is 52mm, the maximum aperture is F2.5, the maximum optical distortion is <1.06%, and the image quality can reach 223pl / mm>0.2MTF. Furthermore, the distance from the front end of the first lens to the rear end of the last lens is less than 108mm, the maximum effective diameter of the lens is less than 24mm, and the maximum target surface can support Φ11.44mm.

[0122] Example 3

[0123] Figure 11 This is a schematic diagram of the structure of a teleconverter lens provided in Embodiment 3 of the present invention, as shown below. Figure 11 As shown, the teleconverter lens provided in Embodiment 3 of the present invention includes a first group S1, a second group S2, and a third group S3 arranged sequentially along the optical axis from the object plane to the image plane; the first group S1 includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, and a fifth lens 105; the second group S2 includes a sixth lens 106, a seventh lens 107, an eighth lens 108, and a ninth lens 109; the third group S3 includes a tenth lens 110, an eleventh lens 111, a twelfth lens 112, and a thirteenth lens 113; wherein, the first lens 101, the third lens 103, the sixth lens 106, the seventh lens 107, the ninth lens 109, the eleventh lens 111, the twelfth lens 112, and the thirteenth lens 113 are all positive power lenses; the second lens 102, the fourth lens 104, the fifth lens 105, the eighth lens 108, and the tenth lens 110 are negative power lenses.

[0124] The rest is the same as in Example 1, and will not be repeated here.

[0125] As another feasible implementation method, the specific parameters of the teleconverter lens are explained below.

[0126] Table 5. Optical design values ​​for the teleconverter lens in Example 2

[0127]

[0128] Table 6 Design values ​​of optical physical parameters for teleconverter lenses

[0129]

[0130] The surface numbers in Table 6 are assigned according to the surface sequence of each lens; the radius of curvature represents the degree of curvature of the lens surface, with positive values ​​indicating that the surface bends towards the image plane and negative values ​​indicating that the surface bends towards the object plane; the thickness represents the central axial distance between the current surface and the next surface; the refractive index represents the ability of the material between the current surface and the next surface to deflect light; a blank space indicates that the current position is air with a refractive index of 1; the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface. Half-aperture indicates half the aperture size of the current surface. The 23rd surface has a spacing of 26.583 mm, allowing focusing to an object distance of 1 m.

[0131] Furthermore, Figure 12 This is a schematic diagram of the beam fan of a teleconverter lens at infinity object distance, provided in Embodiment 3 of the present invention. The beam fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis represents the beam aperture, and the vertical axis represents the transverse aberration. The ideal curve is a straight line coinciding with the horizontal axis, indicating that all rays converge at the same point on the image plane. The interval corresponding to the vertical axis of the curve is the maximum dispersion range of the beam on the ideal image plane. The beam fan diagram can reflect not only monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 12 It can be seen that the system closely approximates the horizontal axis at all wavelengths (435nm, 470nm, 510nm, 555nm, 610nm and 650nm) in all fields of view, indicating that the vertical aberration of each wavelength is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the system is also well corrected, thus ensuring that the optical system can achieve the high-resolution imaging requirements.

[0132] Figure 13 This is a schematic diagram of field curvature distortion of a teleconverter lens at infinity object distance, provided in Embodiment 3 of the present invention. In the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; Figure 13 It can be seen that the lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small, resulting in good consistency; in the coordinate system on the right, the horizontal coordinate represents the magnitude of distortion, expressed as a percentage, while the vertical coordinate represents the normalized image height, which has no unit; from Figure 13 As can be seen, the distortion of the lens provided in this embodiment has been well corrected, with optical distortion less than ±1.06%.

[0133] Figure 14This is an MTF curve of a teleconverter lens at infinity, provided in Embodiment 3 of the present invention. The MTF curve represents the resolving power of the optical system for an object at different frequencies in different fields of view, meridional, and sagittal directions. It reflects the image quality of the object after passing through the optical system. The ideal curve is the diffraction limit at the highest point, indicating the physical limit of the lens under this parameter. The vertical axis of the curve corresponds to the contrast ratio of black and white line boundaries (M' / M), where M refers to the grating modulation degree before imaging, and M' refers to the grating modulation degree after imaging; therefore, 0 ≤ M' / M ≤ 1. The horizontal axis corresponds to the number of black and white lines within 1 mm. S and T correspond to the sagittal and meridional directions of each field of view. Figure 14 As shown, the image quality of the lens of the present invention is higher than 0.2 MTF from the center field of view to the edge field of view, with a resolution of 223 pl / mm.

[0134] Figure 15 This is an MTF curve of a teleconverter lens provided in Embodiment 3 of the present invention at an object distance of 1m. The MTF curve represents the resolving power of the optical system for an object at different frequencies in different fields of view, meridional, and sagittal directions. It reflects the degree of image quality after the object passes through the optical system. The ideal curve is the diffraction limit at the highest point, indicating the physical limit of the lens under this parameter. The vertical axis of the curve corresponds to the contrast ratio of black and white line boundaries (M' / M), where M refers to the grating modulation degree before imaging, and M' refers to the grating modulation degree after imaging. Therefore, 0 ≤ M' / M ≤ 1. The horizontal axis corresponds to the number of black and white lines within 1mm. S and T correspond to the sagittal and meridional directions of each field of view. Figure 15 As shown, the image quality of the lens of the present invention is higher than 0.2 MTF from the center field of view to the edge field of view, with a resolution of 223 pl / mm.

[0135] In summary, the teleconverter lens provided in this embodiment of the invention employs a structure with 13 glass spherical lenses. Through the combination of lens materials and the rational allocation of the optical power of each element, it is adapted to a mobile phone lens with a focal length of 22.48mm, achieving a 2.3x high-definition magnification effect. High resolution can be achieved at focusing distances from 1m to infinity. At infinity, it can maintain low distortion and high-resolution shooting with a large aperture. The overall system focal length is 52mm, the maximum aperture is F2.5, the maximum optical distortion is <1.06%, and the image quality can reach 223pl / mm>0.2MTF. Furthermore, the distance from the front end of the first lens to the rear end of the last lens is less than 108mm, the maximum effective diameter of the lens is less than 24mm, and the maximum target surface can support Φ11.44mm.

[0136] 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 teleconverter lens, characterized in that, This includes the first group, the second group, and the third group, arranged sequentially from the object plane to the image plane along the optical axis; The first group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; the second group includes a sixth lens, a seventh lens, an eighth lens, and a ninth lens; the third group includes a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens; the teleconverter lens has thirteen lenses with optical power. Wherein, the first lens, the third lens, the sixth lens, the seventh lens, the ninth lens, the eleventh lens, the twelfth lens, and the thirteenth lens are all positive power lenses; the second lens, the fourth lens, the fifth lens, the eighth lens, and the tenth lens are negative power lenses; The optical power of the first group is ΦZ1, the optical power of the second group is ΦZ2, and the optical power of the third group is ΦZ3; Among them, 0.0027mm -1 ≤ΦZ1≤0.0033mm -1 0.0268mm -1 ≤ΦZ2≤0.0278mm -1 0.0470mm -1 ≤ΦZ3≤0.0489mm -1 ; The first lens includes a first object-side surface near the object plane and a first image-side surface near the image plane. The first object-side surface is convex, and the first image-side surface is convex. The second lens includes a second object-side surface near the object plane and a second image-side surface near the image plane. The second object-side surface is concave, and the second image-side surface is convex. The third lens includes a third object-side surface near the object plane and a third image-side surface near the image plane. The third object-side surface is convex, and the third image-side surface is convex. The fourth lens includes a fourth object-side surface near the object plane and a fourth image-side surface near the image plane. The fourth object-side surface is concave, and the fourth image-side surface is concave. The fifth lens includes a fifth object-side surface near the object plane and a fifth image-side surface near the image plane. The fifth object-side surface is concave, and the fifth image-side surface is convex. The sixth lens includes a sixth object-side surface near the object plane and a sixth image-side surface near the image plane. The sixth object-side surface is convex, and the sixth image-side surface is convex. The seventh lens includes a seventh object-side surface near the object plane and a seventh image-side surface near the image plane. The seventh object-side surface is convex, and the seventh image-side surface is convex. The eighth lens includes an eighth object-side surface near the object plane and an eighth image-side surface near the image plane. The eighth object-side surface is concave, and the eighth image-side surface is concave. The ninth lens includes a ninth object-side surface near the object plane and a ninth image-side surface near the image plane. The ninth object-side surface is concave, and the ninth image-side surface is convex. The tenth lens includes a tenth object-side surface near the object plane and a tenth image-side surface near the image plane. The tenth object-side surface is either concave or flat, and the tenth image-side surface is concave. The eleventh lens includes an eleventh object-side surface near the object plane and an eleventh image-side surface near the image plane. The eleventh object-side surface is convex, and the eleventh image-side surface is convex. The twelfth lens includes a twelfth object-side surface near the object plane and a twelfth image-side surface near the image plane. The twelfth object-side surface is convex, flat, or concave, and the twelfth image-side surface is convex. The thirteenth lens includes a thirteenth object-side surface near the object plane and a thirteenth image-side surface near the image plane. The thirteenth object-side surface is convex, and the thirteenth image-side surface is convex.

2. The teleconverter lens according to claim 1, characterized in that, The combined optical power of the first and second lenses is Φ1-2, the combined optical power of the third and fourth lenses is Φ3-4, the optical power of the fifth lens is Φ5, the optical power of the sixth lens is Φ6, the combined optical power of the seventh and eighth lenses is Φ7-8, the optical power of the ninth lens is Φ9, the combined optical power of the tenth and eleventh lenses is Φ10-11, the optical power of the twelfth lens is Φ12, and the optical power of the thirteenth lens is Φ13. Among them, 0.0308mm -1 ≤Φ1-2≤0.0309mm -1 -0.0441mm -1 ≤Φ3-4≤-0.0438mm -1 -0.0043mm -1 ≤Φ5≤-0.0030mm -1 0.0390mm -1 ≤Φ6≤0.0395mm -1 -0.0441mm -1 ≤Φ7-8≤-0.0409mm -1 0.0021mm -1 ≤Φ9≤0.0040mm -1 0.0073mm -1 ≤Φ10-11≤0.0143mm -1 0.0215mm -1 ≤Φ12≤0.0245mm -1 0.0205mm -1 ≤Φ13≤0.0221mm -1 .

3. The teleconverter lens according to claim 1, characterized in that, The optical power of the second group is ΦZ2, the combined optical power of the tenth lens, the eleventh lens and the twelfth lens is Φ10-12, and the maximum optical distortion of the teleconverter lens is DISG.MAX; Among them, 0.7792≤ΦZ2 / Φ10-12≤0.9433, 0≤|DISG.MAX|≤1.0549%.

4. The teleconverter lens according to claim 1, characterized in that, The minimum refractive index of the second lens, the fourth lens, the fifth lens, the eighth lens, and the tenth lens is ND_D; Wherein, 1.9111≤ND_D≤1.9113.

5. The teleconverter lens according to claim 1, characterized in that, The first lens and the second lens are cemented together, the third lens and the fourth lens are cemented together, the seventh lens and the eighth lens are cemented together, and the tenth lens and the eleventh lens are cemented together.

6. The teleconverter lens according to claim 5, characterized in that, The Abbe number of the first lens is VD1, the Abbe number of the second lens is VD2, the Abbe number of the third lens is VD3, the Abbe number of the fourth lens is VD4, the Abbe number of the tenth lens is VD10, and the Abbe number of the eleventh lens is VD11. Among them, 2.0145≤VD1 / VD2≤2.1399; 3.3937≤VD3 / VD4≤3.3939; 5.2779≤VD11 / VD10≤5.2879.

7. The teleconverter lens according to claim 1, characterized in that, The teleconverter has an optical length of TTL, a focal length of EFL, a maximum effective aperture of DM, a field of view of FOV, and a magnification of PMAG. Among them, 1.9969≤TTL / EFL≤2.0620; 4.3429≤TTL / DM≤4.4828; 12.3965°≤FOV≤12.4195°; 2.3114≤PMAG≤2.3130.

8. The teleconverter lens according to claim 1, characterized in that, The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens, and the thirteenth lens are all glass spherical lenses.

9. The teleconverter lens according to claim 1, characterized in that, The teleconverter also includes an aperture stop, which is disposed on the image side of the thirteenth lens.

10. An imaging system, characterized in that, Includes the teleconverter lens as described in any one of claims 1-9; The imaging system also includes an imaging lens, which is located on the light-emitting side of the teleconverter lens.

Images