Optical lens

Abstract

The present application relates to an optical lens, which comprises, in order from the object side to the image side along the optical axis, a first lens with negative refractive power, a second lens with negative refractive power, a third lens with positive refractive power, a fourth lens with negative refractive power, a fifth lens with positive refractive power, a sixth lens with negative refractive power, a seventh lens with positive refractive power, an eighth lens with negative refractive power, a ninth lens with negative refractive power, a tenth lens with positive refractive power and an eleventh lens with positive refractive power. The optical lens has at least one of the following characteristics: a large aperture (F1.2), an infrared confocal function, 2K high image quality, support for dual optical path imaging and distance measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to an optical lens with one of the following characteristics: large aperture, infrared confocal, 2K high image quality, supporting dual optical path imaging and ranging. BACKGROUND

[0002] In many observation application scenarios, accurate observation of object details is crucial. However, due to the small object field angle in actual applications, it is urgent to have a lens with a long focal length. A long focal length lens can focus on a specific area, magnify distant objects, and allow the observer to clearly capture the fine details of the object, greatly improving the accuracy of observation.

[0003] At the same time, in actual use environment, there are often insufficient lighting conditions such as night scene, dusk, rainy day, etc. In order to obtain clear images under these conditions, the requirement of large aperture arises at the historic moment.

[0004] In order to meet the needs of night observation, infrared confocal technology becomes the key. At night, the lack of visible light makes the observation effect of traditional lenses greatly discounted.

[0005] Further, in order to realize the functions of simultaneous imaging and ranging, the requirement of long back focal length is indispensable. Long back focal length can reserve enough space for the rear of the lens, which is conducive to the design of dual optical path imaging of the optical system, and also helps to realize ranging, providing important data support for subsequent analysis and decision-making.

[0006] The optical lenses on the market today still have the following shortcomings:

[0007] 1. The existing optical lenses are difficult to balance large aperture and high image quality;

[0008] 2. The existing optical lenses are difficult to correct chromatic aberration and realize infrared confocal;

[0009] 3. The existing optical lenses balance short total length and long back focal length.

[0010] Therefore, it has become a market development trend to design an optical lens with one of the following characteristics: large aperture, infrared confocal, 2K high image quality, etc. SUMMARY

[0011] In order to solve the problems existing in the prior art, the purpose of the present application is to provide an optical lens with at least one of the following characteristics: large aperture, infrared confocal, 2K high image quality, etc.

[0012] In order to achieve the above application purpose, the present application provides an optical lens, which comprises, in order along the optical axis from the object side to the image side:

[0013] The first lens has a negative optical power, the second lens has a negative optical power, the third lens has a positive optical power, the fourth lens has a negative optical power, the fifth lens has a positive optical power, the sixth lens has a negative optical power, the seventh lens has a positive optical power, the eighth lens has a negative optical power, the ninth lens has a negative optical power, the tenth lens has a positive optical power, and the eleventh lens has a positive optical power.

[0014] According to one of the technical solutions of the present application, the first lens is a convex-concave lens, the second lens is a concave-convex lens, the third lens is a convex-concave lens, the image side surface of the fourth lens is a concave surface, the image side surface of the fifth lens is a convex surface, the sixth lens is a concave-concave lens, the seventh lens is a convex-convex lens, and the eighth lens is a concave-convex lens.

[0015] According to one of the technical solutions of the present application, the ninth lens is a convex-concave lens, the object side surface of the tenth lens is a convex surface, and the object side surface of the eleventh lens is a convex surface.

[0016] According to one of the technical solutions of the present application, the fifth lens and the sixth lens form a first doublet cemented lens.

[0017] According to one of the technical solutions of the present application, the seventh lens and the eighth lens form a second doublet cemented lens.

[0018] According to one of the technical solutions of the present application, the ninth lens and the tenth lens form a third doublet cemented lens.

[0019] According to one of the technical solutions of the present application, the maximum total aperture Dmax of the optical lens and the total optical length TTL satisfy the following relationship: 0.3≤Dmax / TTL≤0.4.

[0020] According to one of the technical solutions of the present application, the total optical length TTL of the optical lens and the effective focal length F satisfy the following relationship: 4.0≤TTL / F≤4.3.

[0021] According to one of the technical solutions of the present application, the total optical length TTL of the optical lens and the back focal length BFL satisfy the following relationship: 2.5≤TTL / BFL≤2.8.

[0022] According to one of the technical solutions of the present application, the effective focal length F1 of the first lens and the effective focal length F of the optical lens satisfy the following relationship: -5.4≤F1 / F≤-3.0.

[0023] According to one of the technical solutions of the present application, the effective focal length F2 of the second lens and the effective focal length F of the optical lens satisfy the following relationship: -4.3≤F2 / F≤-3.3.

[0024] According to one of the technical solutions of the present application, the effective focal length F3 of the third lens and the effective focal length F of the optical lens satisfy the following relationship: 1.2≤F3 / F≤2.3.

[0025] According to one of the technical solutions of the present application, the effective focal length F4 of the fourth lens and the effective focal length F of the optical lens satisfy the following relationship: -1.7≤F4 / F≤-0.7.

[0026] According to one of the technical solutions of the present application, the effective focal length F5 of the fifth lens and the effective focal length F of the optical lens satisfy the following relationship: 0.7≤F5 / F≤1.7.

[0027] According to one of the technical solutions of the present application, the effective focal length F6 of the sixth lens and the effective focal length F of the optical lens satisfy the following relationship: -1.0≤F6 / F≤-0.5.

[0028] According to one of the technical solutions of the present application, the effective focal length F7 of the seventh lens and the effective focal length F of the optical lens satisfy the following relationship: 0.85≤F7 / F≤1.00.

[0029] According to one of the technical solutions of the present application, the effective focal length F8 of the eighth lens and the effective focal length F of the optical lens satisfy the following relationship: -2.6≤F8 / F≤-1.7.

[0030] According to one of the technical solutions of the present application, the effective focal length F9 of the ninth lens and the effective focal length F of the optical lens satisfy the following relationship: -3.0≤F9 / F≤-1.6.

[0031] According to one of the technical solutions of the present application, the effective focal length F10 of the tenth lens and the effective focal length F of the optical lens satisfy the following relationship: 1.0≤F10 / F≤2.0.

[0032] According to one of the technical solutions of the present application, the effective focal length F11 of the eleventh lens and the effective focal length F of the optical lens satisfy the following relationship: 1.6≤F11 / F≤3.2.

[0033] According to one of the technical solutions of the present application, the combined focal length Fa of the fifth lens and the sixth lens and the effective focal length F of the optical lens satisfy the following relationship: -4.2≤Fa / F≤-1.3.

[0034] According to one of the technical solutions of the present application, the combined focal length Fb of the seventh lens and the eighth lens and the effective focal length F of the optical lens satisfy the following relationship: 1.3≤Fb / F≤1.8.

[0035] According to one of the technical solutions of the present application, the combined focal length Fc of the ninth lens and the tenth lens and the effective focal length F of the optical lens satisfy the following relationship: 1.6≤Fc / F≤6.0.

[0036] According to one of the technical solutions of the present application, the combined focal length FI of the first lens to the sixth lens and the effective focal length F of the optical lens satisfy the following relationship: -1.0≤FI / F≤-0.5.

[0037] According to one of the technical solutions of the present application, the combined focal length FII of the seventh lens to the eleventh lens and the effective focal length F of the optical lens satisfy the following relationship: 0.6≤FII / F≤1.0.

[0038] According to one of the technical solutions of the present application, the combined focal length FI of the first lens to the sixth lens and the combined focal length FII of the seventh lens to the eleventh lens satisfy the following relationship: -1.2≤FI / FII≤-0.6.

[0039] According to one of the technical solutions of the present application, the optical lens at least satisfies one of the following conditions:

[0040] 0.3≤Dmax / TTL≤0.4,

[0041] 4.0≤TTL / F≤4.1,

[0042] 2.55≤TTL / BFL≤2.75,

[0043] -5.1≤F1 / F≤-3.3,

[0044] -4.15≤F2 / F≤-3.45,

[0045] 1.4≤F3 / F≤2.1,

[0046] -1.5≤F4 / F≤-0.9,

[0047] 0.9≤F5 / F≤1.3,

[0048] -0.9≤F6 / F≤-0.6,

[0049] 0.85≤F7 / F≤1.00,

[0050] -2.4≤F8 / F≤-1.85,

[0051] -2.85≤F9 / F≤-1.8,

[0052] 1.2≤F10 / F≤1.8,

[0053] 1.8≤F11 / F≤3,

[0054] -4≤Fa / F≤-1.48,

[0055] 1.4≤Fb / F≤1.7,

[0056] 2≤Fc / F≤5.68,

[0057] -0.85≤FI / F≤-0.65,

[0058] 0.75≤FII / F≤0.9,

[0059] -1.05≤FI / FII≤-0.8,

[0060] Wherein, Dmax is the maximum light passing full aperture of the optical lens, TTL is the optical total length of the optical lens, F is the effective focal length of the optical lens, BFL is the back focal length of the optical lens, F1 is the effective focal length of the first lens, F2 is the effective focal length of the second lens, F3 is the effective focal length of the third lens, F4 is the effective focal length of the fourth lens, F5 is the effective focal length of the fifth lens, F6 is the effective focal length of the sixth lens, F7 is the effective focal length of the seventh lens, F8 is the effective focal length of the eighth lens, F9 is the effective focal length of the ninth lens, F10 is the effective focal length of the tenth lens, F11 is the effective focal length of the eleventh lens, Fa is the combined focal length of the fifth lens and the sixth lens, Fb is the combined focal length of the seventh lens and the eighth lens, Fc is the combined focal length of the ninth lens and the tenth lens, FI is the combined focal length of the first lens to the sixth lens, FII is the combined focal length of the seventh lens to the eleventh lens.

[0061] According to the scheme of the present application, by setting the optical lens to include eleven lenses, and setting the optical power of the first lens to the eighth lens to be negative optical power, negative optical power, positive optical power, negative optical power, positive optical power, negative optical power, positive optical power, negative optical power, negative optical power, positive optical power, and positive optical power respectively, the present application can take into account both large aperture and high image quality, and can also take into account short total length and long back focus, so that the optical lens at least has one of the characteristics of large aperture (F1.2), can realize infrared confocal, 2K high image quality, supports double optical path imaging and ranging, etc. BRIEF DESCRIPTION OF DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0063] Figure 1 Structure diagram of the optical lens of embodiment one in the present application;

[0064] Figure 2 Relative luminance diagram of the optical lens of embodiment one in the present application;

[0065] Figure 3 Transverse ray fan diagram of the optical lens of embodiment one in the present application;

[0066] Figure 4 Structure diagram of the optical lens of embodiment two in the present application;

[0067] Figure 5 Relative luminance diagram of the optical lens of embodiment two in the present application;

[0068] Figure 6 Transverse ray fan diagram of the optical lens of embodiment two in the present application;

[0069] Figure 7 Structure diagram of the optical lens of embodiment three in the present application;

[0070] Figure 8 Relative luminance diagram of the optical lens of embodiment three in the present application;

[0071] Figure 9 Transverse ray fan diagram of the optical lens of embodiment three in the present application;

[0072] Figure 10 Structure diagram of the optical lens of embodiment four in the present application;

[0073] Figure 11 Relative luminance diagram of the optical lens of embodiment four in the present application;

[0074] Figure 12 Transverse ray fan diagram of the optical lens of embodiment four in the present application. DETAILED DESCRIPTION

[0075] For a better understanding of the present application, various aspects of the application will be described in more detail below with reference to the accompanying drawings. It is to be understood that the detailed description is merely descriptive of exemplary embodiments of the application and not intended to limit the scope of the application in any way. Throughout the description, like reference numerals refer to like elements. The expression “and / or” includes any and all combinations of one or more of the associated listed items.

[0076] It should be noted that the expressions first, second, third, etc. in the present specification are only used to distinguish one feature from another, and do not represent any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the first lens.

[0077] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0078] In this context, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If the lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0079] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. Furthermore, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0080] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the terms should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0081] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The following embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but should not be understood as limitations on the scope of the patent of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application.

[0082] As shown in Figures 1 to 12 An embodiment of the present application provides an optical lens, which comprises, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a stop STO, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L8, an eighth lens L9, a ninth lens L10, a tenth lens L11 and a protective flat glass CG.

[0083] The first lens L1 has a negative focal power, is beneficial to expand the incident light of the rear optical lens, corrects the large aperture light aberration, and realizes a large aperture.

[0084] The first lens L1 is located at the first piece and is a convex-concave crescent-shaped lens, which is beneficial to reduce the incident angle of the on-axis light and reduce the generation of spherical aberration, and is beneficial to reduce the tolerance sensitivity.

[0085] Further, the first lens L1 can select a material with positive abnormal dispersion and a large value, such as FK / ZPK series material with low refractive index and high Abbe number, or ZF series material with high refractive index and low Abbe number, which is beneficial to wide-spectrum compound achromatism and realizes infrared confocal.

[0086] The second lens L2 has a negative focal power, shares the negative focal power of the first lens L1, reduces the surface curvature, reduces the generation of aberration, and is beneficial to realize high image quality.

[0087] The first lens L1 and the second lens L2 are used in cooperation, and the combined focal length has a large negative focal power, which is beneficial to expand the incident light of the rear optical lens, correct the large aperture light aberration, and realize a large aperture.

[0088] The first lens L1 and the second lens L2 are symmetric crescent-shaped and located at the front end of the lens, farthest from the stop, introduce axial aberrations such as astigmatism and coma, thereby balancing the large field of view light aberration, and are beneficial to realize a large target surface.

[0089] The third lens L3 has a positive focal power, converges the light of the optical lens, is beneficial to correct the high-order aberration of the optical lens, and realizes a large aperture.

[0090] The object side surface of the third lens L3 is a convex surface, introduces positive spherical aberration to balance the negative spherical aberration generated by the first lens L1 and the second lens L2, and is beneficial to realize high image quality.

[0091] The image side surface of the third lens L3 is a concave surface, which is beneficial to reduce the incident angle of the on-axis light and reduce the generation of spherical aberration, and is beneficial to reduce the tolerance sensitivity.

[0092] The third lens L3 can select a high refractive index material, increase the positive focal power, reduce the surface curvature, be beneficial to reduce the generation of aberration, and realize high image quality.

[0093] The third lens L3 can select a material with positive and large abnormal dispersion, which is beneficial to wide spectrum complex aplanatization and realization of infrared confocal.

[0094] The fourth lens L4 has negative optical power, which is beneficial to the incident light of the beam expansion rear system, correction of large aperture aberration, and realization of large aperture;

[0095] The image side of the fourth lens L4 is a concave surface, which introduces negative spherical aberration to balance the positive spherical aberration generated by the third lens L3, and is beneficial to realization of high image quality; when the object side and the image side of the fourth lens L4 are both concave, the optical power can be shared, the surface curvature is reduced, the generation of aberration is reduced, and high image quality is beneficial to realization of high image quality; when the object side of the fourth lens L4 is a convex surface, it is beneficial to reduce the incidence angle of the on-axis light and reduce the generation of spherical aberration, and is beneficial to reduce the tolerance sensitivity;

[0096] The fourth lens L4 can select a material with negative and small abnormal dispersion, such as TF series material, which is beneficial to wide spectrum complex aplanatization and realization of infrared confocal.

[0097] The fifth lens L5 and the sixth lens L6 form a first double cemented lens, the fifth lens L5 has positive optical power in the first double cemented lens, the sixth lens L6 has negative optical power in the first double cemented lens, and the fifth lens L5 and the sixth lens L6 cooperate to realize complex aplanatization, which is beneficial to realization of high image quality; when the object side and the image side of the fifth lens L5 are both convex, the optical power is shared, the surface curvature is reduced, the generation of aberration is reduced, and high image quality is beneficial to realization of high image quality; or when the object side of the fifth lens L5 is a plane, the incidence angle of the on-axis light is reduced, the generation of spherical aberration is reduced, and high image quality is beneficial to realization of high image quality;

[0098] The fifth lens L5 can select a material with positive and large abnormal dispersion, which is beneficial to wide spectrum complex aplanatization and realization of infrared confocal.

[0099] The object side and the image side of the sixth lens L6 are both negative, which shares the optical power, reduces the surface curvature, reduces the generation of aberration, and is beneficial to realization of high image quality.

[0100] The seventh lens L7 and the eighth lens L8 form a second double cemented lens, the seventh lens L7 has positive optical power in the second double cemented lens, the eighth lens L8 has negative optical power in the second double cemented lens, and the seventh lens L7 and the eighth lens L8 cooperate to realize complex aplanatization, which is beneficial to realization of high image quality;

[0101] The object side and the image side of the seventh lens L7 are both convex, which shares the optical power, reduces the surface curvature, reduces the generation of aberration, and is beneficial to realization of high image quality;

[0102] The seventh lens L7 can be made of a material with positive anomalous dispersion and a large numerical value, which is beneficial to wide-spectrum complex aplanatization and realization of infrared confocal.

[0103] The eighth lens L8 is a concave-convex lens, which is beneficial to reducing the incidence angle of on-axis light and reducing the generation of spherical aberration, and is beneficial to reducing the tolerance sensitivity.

[0104] The ninth lens L9 and the tenth lens L10 form a third doublet lens, the ninth lens L9 has negative refractive power in the third doublet lens, the tenth lens L10 has positive refractive power in the third doublet lens, and the ninth lens L9 and the tenth lens L10 cooperate to realize complex aplanatization and are beneficial to realizing high image quality.

[0105] The ninth lens L9 is a convex-concave lens, which effectively controls the light path and is beneficial to reducing the incidence angle of on-axis light, reducing the generation of spherical aberration, and reducing the tolerance sensitivity.

[0106] The object side of the tenth lens L10 is convex, and the image side is concave, which effectively controls the light path, is beneficial to reducing the incidence angle of on-axis light, reducing the generation of spherical aberration, and reducing the tolerance sensitivity.

[0107] The object side and the image side of the tenth lens L10 are both convex, which share the optical power, reduces the surface curvature, reduces the generation of aberration, and is beneficial to realizing high image quality.

[0108] The tenth lens L10 can be made of a material with positive anomalous dispersion and a large numerical value, which is beneficial to wide-spectrum complex aplanatization and realization of infrared confocal.

[0109] The eleventh lens L11 has positive refractive power, forms a rear group lens with large positive refractive power together with the seventh lens L7, the eighth lens L8, the ninth lens L9, and the tenth lens L10, and constitutes a reverse telephoto architecture together with a front group lens (the first lens L1 to the sixth lens L6), which is beneficial to increasing the back focus and providing a structure space to realize split-beam ranging.

[0110] The object side of the eleventh lens L11 is a convex surface, which is beneficial to reducing the generation of spherical aberration and realizing high image quality of the lens.

[0111] By controlling the size of the system entrance pupil diameter, the system has a small aperture value, which is beneficial to realizing a large aperture, and the aperture value can reach F1.0-F1.3.

[0112] In some embodiments of the present application, the maximum total light aperture Dmax of the optical lens and the total optical length TTL satisfy the following relationship: 0.3≤Dmax / TTL≤0.4. By controlling the maximum total light aperture of the system under certain total optical length, the maximum total light aperture of the system is small, which is beneficial to miniaturization.

[0113] In some embodiments of the present application, the optical total length TTL of the optical lens and the effective focal length F satisfy the following relationship: 4.0≤TTL / F≤4.3, preferably 4.0≤TTL / F≤4.1. In the case of a certain focal length value, by controlling the optical total length of the optical lens, the system optical total length is small, which is beneficial to miniaturization.

[0114] In some embodiments of the present application, the optical total length TTL of the optical lens and the back focal length BFL satisfy the following relationship: 2.5≤TTL / BFL≤2.8, preferably 2.55≤TTL / BFL≤2.75. On the basis of realizing miniaturization, by controlling the system optical back focal length, the long back focal length of the lens is beneficial to guarantee, which can reserve enough space for the rear of the lens, is beneficial to realize the double optical path imaging design of the optical system, and is also helpful for the realization of ranging.

[0115] In some embodiments of the present application, the effective focal length F1 of the first lens L1 and the effective focal length F of the optical lens satisfy the following relationship: -5.4≤F1 / F≤-3.0, preferably -5.1≤F1 / F≤-3.3. By reasonably allocating the focal length value of the first lens L1, the incident light of the system behind the beam expander is beneficial to be expanded, the large aperture light aberration is corrected, the resolving power of the lens is improved, and a large aperture is also helpful.

[0116] In some embodiments of the present application, the effective focal length F2 of the second lens L2 and the effective focal length F of the optical lens satisfy the following relationship: -4.3≤F2 / F≤-3.3, preferably -4.15≤F2 / F≤-3.45. By reasonably allocating the focal length value of the second lens L2, the negative optical power of the first lens L1 is shared, the surface curvature is reduced, the aberration is reduced, and high image quality is beneficial to realize.

[0117] In some embodiments of the present application, the effective focal length F3 of the third lens L3 and the effective focal length F of the optical lens satisfy the following relationship: 1.2≤F3 / F≤2.3, preferably 1.4≤F3 / F≤2.1. By reasonably allocating the focal length value of the third lens L3, the system light is convergent, which is beneficial to correct the high-order aberration of the system, improve the resolving power of the lens, and also help to realize a large aperture.

[0118] In some embodiments of the present application, the effective focal length F4 of the fourth lens L4 and the effective focal length F of the optical lens satisfy the following relationship: -1.7≤F4 / F≤-0.7, preferably -1.5≤F4 / F≤-0.9. By reasonably allocating the focal length value of the fourth lens L4, the incident light of the system behind the beam expander is beneficial to be expanded, the large aperture light aberration is corrected, the resolving power of the lens is improved, and a large aperture is also helpful.

[0119] In some embodiments of the present application, the effective focal length F5 of the fifth lens L5 and the effective focal length F of the optical lens satisfy the following relationship: 0.7≤F5 / F≤1.7, preferably, 0.9≤F5 / F≤1.3. By reasonably allocating the focal length value of the fifth lens L5 so that it has positive refractive power in the double cemented lens, selecting a material with large anomalous dispersion, and cooperating with the sixth lens L6 to achieve complex aplanatism, high image quality is facilitated.

[0120] In some embodiments of the present application, the effective focal length F6 of the sixth lens L6 and the effective focal length F of the optical lens satisfy the following relationship: -1.0≤F6 / F≤-0.5, preferably, -0.9≤F6 / F≤-0.6. By reasonably allocating the focal length value of the sixth lens L6 so that it has negative refractive power in the double cemented lens, cooperating with the fifth lens L5 with positive refractive power to facilitate the realization of complex aplanatism and high image quality of the lens.

[0121] In some embodiments of the present application, the effective focal length F7 of the seventh lens L7 and the effective focal length F of the optical lens satisfy the following relationship: 0.85≤F7 / F≤1.00. By reasonably allocating the focal length value of the seventh lens L7 so that it has positive refractive power in the double cemented lens, selecting a material with large anomalous dispersion, and cooperating with the eighth lens L8 with negative refractive power to achieve complex aplanatism, high image quality is facilitated.

[0122] In some embodiments of the present application, the effective focal length F8 of the eighth lens L8 and the effective focal length F of the optical lens satisfy the following relationship: -2.6≤F8 / F≤-1.7, preferably, -2.4≤F8 / F≤-1.85. By reasonably allocating the focal length value of the eighth lens L8 so that it has negative refractive power in the double cemented lens, cooperating with the seventh lens L7 with positive refractive power to facilitate the realization of complex aplanatism and high image quality.

[0123] In some embodiments of the present application, the effective focal length F9 of the ninth lens L9 and the effective focal length F of the optical lens satisfy the following relationship: -3.0≤F9 / F≤-1.6, preferably, -2.85≤F9 / F≤-1.8. By reasonably allocating the focal length value of the ninth lens L9 so that it has negative refractive power in the double cemented lens, cooperating with the tenth lens L10 with positive refractive power to facilitate the realization of complex aplanatism and high image quality.

[0124] In some embodiments of the present application, the effective focal length F10 of the tenth lens L10 and the effective focal length F of the optical lens satisfy the following relationship: 1.0≤F10 / F≤2.0, preferably, 1.2≤F10 / F≤1.8. By reasonably allocating the focal length value of the tenth lens L10 so that it has positive refractive power in the double cemented lens, selecting a material with large anomalous dispersion, and cooperating with the ninth lens L9 with negative refractive power to achieve complex aplanatism, high image quality is facilitated.

[0125] In some embodiments of the present application, the effective focal length F11 of the eleventh lens L11 and the effective focal length F of the optical lens satisfy the following relationship: 1.6≤F11 / F≤3.2, preferably, 1.8≤F11 / F≤3. By reasonably allocating the focal length value of the eleventh lens L11, making it have positive refractive power, introducing negative spherical aberration, it is beneficial to correct the residual spherical aberration of the system, and it is beneficial to realize high image quality.

[0126] In some embodiments of the present application, the combined focal length Fa of the fifth lens L5 and the sixth lens L6 and the effective focal length F of the optical lens satisfy the following relationship: -4.2≤Fa / F≤-1.3, preferably, -4≤Fa / F≤-1.48. By reasonably allocating the focal length values of the fifth lens L5 and the sixth lens L6 of the doublet lens, cooperating with a larger light aperture, it is beneficial to correct the on-axis chromatic aberration of a large aperture, improve the quality of the lens, and at the same time help to realize a large aperture.

[0127] In some embodiments of the present application, the combined focal length Fb of the seventh lens L7 and the eighth lens L8 and the effective focal length F of the optical lens satisfy the following relationship: 1.3≤Fb / F≤1.8, preferably, 1.4≤Fb / F≤1.7. By reasonably allocating the focal length values of the seventh lens L7 and the eighth lens L8 of the doublet lens, cooperating with a larger light aperture, it is beneficial to correct the on-axis chromatic aberration of a large aperture, improve the quality of the lens, and at the same time help to realize a large aperture.

[0128] In some embodiments of the present application, the combined focal length Fc of the ninth lens L9 and the tenth lens L10 and the effective focal length F of the optical lens satisfy the following relationship: 1.6≤Fc / F≤6.0, preferably, 2≤Fc / F≤5.68. By reasonably allocating the focal length values of the ninth lens L9 and the tenth lens L10 of the doublet lens, cooperating with a larger light aperture, it is beneficial to correct the on-axis chromatic aberration of a large aperture, improve the quality of the lens, and at the same time help to realize a large aperture.

[0129] In some embodiments of the present application, the combined focal length FI of the first lens L1 to the sixth lens L6 and the effective focal length F of the optical lens satisfy the following relationship: -1.0≤FI / F≤-0.5, preferably, -0.85≤FI / F≤-0.65;

[0130] The combined focal length FII of the seventh lens L7 to the eleventh lens L11 and the effective focal length F of the optical lens satisfy the following relationship: 0.6≤FII / F≤1.0, preferably, 0.75≤FII / F≤0.9;

[0131] The combined focal length FI of the first lens L1 to the sixth lens L6 and the combined focal length FII of the seventh lens L7 to the eleventh lens L11 satisfy the following relationship: -1.2≤FI / FII≤-0.6, preferably -1.05≤FI / FII≤-0.8.

[0132] In some embodiments of the present application, any lens of the optical lens of the present application can be selected from a spherical lens or an aspherical lens. According to the need, the present application does not specifically limit the specific number of spherical lenses and aspherical lenses. When the imaging quality is emphasized, the number of aspherical lenses can be increased, and even all lenses use aspherical lenses. For example, the first lens to the eleventh lens in the present application are spherical lenses.

[0133] In some embodiments of the present application, the optical lens of the present application can use a glass-plastic hybrid material or a full glass material. The optical lens made of glass can suppress the shift of the back focus of the optical lens with the change of temperature, so as to improve the system stability. At the same time, the use of glass material can avoid the imaging blur of the lens caused by the high and low temperature changes in the use environment, which affects the normal use of the lens, and also can better correct the system chromatic aberration, improve the resolution of the lens, and reduce the generation of ghosting. The optical lens made of plastic can effectively reduce the manufacturing cost, and reasonable collocation of plastic lenses is conducive to the balance of high and low temperature and the realization of infrared confocal. For example, the first lens to the eleventh lens in the present application are glass lenses. The optical lens with full glass design has a wide temperature range, and can maintain stable optical performance in the range of -40℃ to 85℃.

[0134] By reasonably distributing the combined focal length values of the first lens L1 to the sixth lens L6 and the combined focal length values of the seventh lens L7 to the eleventh lens L11, a reverse telephoto architecture is formed, which is conducive to increasing the back focus length and providing sufficient structural space to realize the light splitting and ranging of the lens.

[0135] Further, a light splitting plate is arranged behind (image side) the eleventh lens. The light splitting plate can be a beam splitter. A protective glass and a ranging detector are arranged behind the beam splitter. Another protective glass and an image plane are arranged above or below the beam splitter, so as to realize the synchronous completion of imaging and ranging.

[0136] The following four groups of specific embodiments are given according to the above settings of the present application to specifically illustrate the optical lens according to the present application. The optical lens according to the present application has a total of eleven lenses. Each cemented surface of the cemented lens is recorded as a surface. In addition, there are a diaphragm STO, a protective glass CG and an image plane IMA / ranging detector, a total of 23 surfaces. The diaphragm STO is arranged between the eighth lens L8 and the ninth lens L9.

[0137] The data of the four groups of embodiments are as follows in Table 1:

[0138]

[0139]

[0140] Table 1

[0141] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments, which cannot be exhaustively listed here, but the embodiments of the present application are not limited to the following embodiments.

[0142] Embodiment One

[0143] Figure 1 Structure diagram of the optical lens in Embodiment One of the present application;

[0144] Figure 2 Relative luminance diagram of the optical lens in Embodiment One of the present application;

[0145] Figure 3 Transverse ray fan diagram of the optical lens in Embodiment One of the present application.

[0146] In Embodiment One, the first lens L1 is a convex-concave lens with negative focal power, the second lens L2 is a concave-convex lens with negative focal power, the third lens L3 is a convex-concave lens with positive focal power, the fourth lens L4 is a concave-concave lens with negative focal power, the fifth lens L5 is a convex-convex lens with positive focal power, the sixth lens L6 is a concave-concave lens with negative focal power, the seventh lens L7 is a convex-convex lens with positive focal power, the eighth lens L8 is a concave-convex lens with negative focal power, the ninth lens L9 is a convex-concave lens with negative focal power, the tenth lens L10 is a convex-concave / convex-flat lens with positive focal power, and the eleventh lens L11 is a convex-concave lens with positive focal power.

[0147] The first lens L1 to the eleventh lens L11 are all spherical lenses; the stop STO is arranged between the eighth lens L8 and the ninth lens L9.

[0148] Table 2 lists the related parameters of each lens in the optical lens of the present embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd of the material, and Abbe number Vd.

[0149]

[0150]

[0151] Table 2

[0152] In combination Figures 1 to 3 In combination with the above Table 1 and Table 2, in Embodiment One, the effective focal length F of the optical lens is 31 mm, the total optical length is 125 mm, and the F number Fno is 1.22.

[0153] The first embodiment is an optical lens having at least one of the following characteristics: a large aperture (F1.2), infrared confocal, 2K high image quality, support for dual optical path imaging and ranging, etc.

[0154] Embodiment two

[0155] Figure 4 The structure diagram of the optical lens of embodiment two in the application is shown in the figure;

[0156] Figure 5 The relative luminance diagram of the optical lens of embodiment two in the application is shown in the figure;

[0157] Figure 6 The transverse ray fan diagram of the optical lens of embodiment two in the application is shown in the figure.

[0158] In embodiment two, the first lens L1 is a convex-concave lens with negative focal power, the second lens L2 is a concave-convex lens with negative focal power, the third lens L3 is a convex-concave lens with positive focal power, the fourth lens L4 is a concave-concave lens with negative focal power, the fifth lens L5 is a plano-convex lens with positive focal power, the sixth lens L6 is a concave-concave lens with negative focal power, the seventh lens L7 is a convex-convex lens with positive focal power, the eighth lens L8 is a concave-convex lens with negative focal power, the ninth lens L9 is a convex-concave lens with negative focal power, the tenth lens L10 is a convex-convex lens with positive focal power, and the eleventh lens L11 is a convex-concave lens with positive focal power.

[0159] The first lens L1 to the eleventh lens L11 are all spherical lenses; and the stop STO is arranged between the eighth lens L8 and the ninth lens L9.

[0160] Table 3 lists the related parameters of each lens in the optical lens of the embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd of the material, and Abbe number Vd.

[0161] Surface No. Surface Type Radius of Curvature R Thickness d Refractive Index Nd Abbe Number Vd S1 Sphere 28.282 6.08 1.70 35.3 S2 Sphere 20.507 6.43 S3 Sphere -25.746 5.89 1.49 70.4 S4 Sphere -50.974 0.30 S5 Sphere 24.498 6.33 1.92 18.9 S6 Sphere 37.234 3.06 S7 Sphere -453.405 0.80 1.65 39.5 S8 Sphere 25.056 4.11 S9 Sphere Sphere 8.35 1.44 95.1 S10 Infinity -16.808 0.80 1.61 44.1 S11 Sphere 315.683 0.30 S12 Sphere 88.396 14.62 1.59 68.3 S13 Sphere -20.451 0.80 1.61 44.1 S14 Sphere -38.395 0.30 Sphere STO 0.300 42.26 S16 Sphere 143.787 0.80 1.74 30.5 S17 Sphere 33.181 12.42 1.59 68.3 S18 Sphere -69.930 0.30 S19 Sphere 42.880 6.30 1.74 44.9 S20 Sphere 535.839 45.05 S21 Sphere Infinity 0.70 1.52 64.2 S22 Sphere Infinity 1.00 IMA Sphere Infinity

[0162] Table 3

[0163] In combination Figures 4 to 6 In addition, as shown in Table 1 and Table 3, in embodiment two, the effective focal length F of the optical lens is 31 mm, the total optical length is 125 mm, and the aperture number Fno is 1.22.

[0164] The second embodiment is an optical lens having at least one of the following characteristics: a large aperture (F1.2), infrared confocal, 2K high image quality, support for dual optical path imaging and ranging, etc.

[0165] Embodiment three

[0166] Figure 7 Structure diagram of the optical lens in Embodiment Three of the present application;

[0167] Figure 8 Relative luminance diagram of the optical lens in Embodiment Three of the present application;

[0168] Figure 9 Transverse ray fan diagram of the optical lens in Embodiment Three of the present application.

[0169] In Embodiment Three, the first lens L1 is a convex-concave lens with negative focal power, the second lens L2 is a concave-convex lens with negative focal power, the third lens L3 is a convex-concave lens with positive focal power, the fourth lens L4 is a convex-concave lens with negative focal power, the fifth lens L5 is a convex-convex lens with positive focal power, the sixth lens L6 is a concave-concave lens with negative focal power, the seventh lens L7 is a convex-convex lens with positive focal power, the eighth lens L8 is a concave-convex lens with negative focal power, the ninth lens L9 is a convex-concave lens with negative focal power, the tenth lens L10 is a convex-convex lens with positive focal power, and the eleventh lens L11 is a convex-concave lens with positive focal power.

[0170] The first lens L1 to the eleventh lens L11 are all spherical lenses; and the stop STO is arranged between the eighth lens L8 and the ninth lens L9.

[0171] Table 4 lists the related parameters of each lens in the optical lens of the present embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd of the material, and Abbe number Vd.

[0172] Surface No. Surface Type Radius of Curvature R Thickness d Refractive Index Nd Abbe Number Vd S1 Sphere 35.280 0.80 1.49 70.4 S2 Sphere 22.236 7.24 S3 Sphere -27.208 2.62 1.50 61.6 S4 Sphere -51.431 0.30 S5 Sphere 27.149 10.28 1.92 20.9 S6 Sphere 46.160 1.85 S7 Sphere 167.378 0.80 1.65 39.5 S8 Sphere 25.082 3.87 S9 Sphere 263.024 9.85 1.44 95.1 S10 Sphere -16.555 0.80 1.65 39.5 S11 Sphere 66.102 0.55 S12 Sphere 76.742 14.83 1.59 68.3 S13 Sphere -20.124 0.80 1.58 41.6 S14 Sphere -40.644 0.30 STO Sphere Infinity 0.30 S16 Sphere 112.918 0.80 1.64 34.8 S17 Sphere 37.142 15.40 1.59 68.3 S18 Sphere -50.018 0.30 S19 Sphere 44.015 5.03 1.74 44.9 S20 Sphere 117.784 46.57 S21 Sphere Infinity 0.70 1.52 64.2 S22 Sphere Infinity 1.00 IMA Sphere Infinity

[0173] Table 4

[0174] In combination Figures 7 to 9 In addition, as shown in Table 1 and Table 4 above, in Embodiment Three, the effective focal length F of the optical lens is 31 mm, the total optical length is 125 mm, and the F number Fno is 1.22.

[0175] Embodiment Three is an optical lens having at least one of the following characteristics: large aperture (F1.2), infrared confocal, 2K high image quality, supporting dual optical path imaging and ranging, etc.

[0176] Embodiment Four

[0177] Figure 10 Structure diagram of the optical lens in Embodiment Four of the present application;

[0178] Figure 11 Relative luminance diagram of the optical lens in Embodiment Four of the present application;

[0179] Figure 12 A transverse ray fan diagram of the optical lens of Example Four of the present application.

[0180] In Example Four, the first lens L1 is a convex-concave lens with negative refractive power, the second lens L2 is a concave-convex lens with negative refractive power, the third lens L3 is a convex-concave lens with positive refractive power, the fourth lens L4 is a concave-concave lens with negative refractive power, the fifth lens L5 is a convex-convex lens with positive refractive power, the sixth lens L6 is a concave-concave lens with negative refractive power, the seventh lens L7 is a convex-convex lens with positive refractive power, the eighth lens L8 is a concave-convex lens with negative refractive power, the ninth lens L9 is a convex-concave lens with negative refractive power, the tenth lens L10 is a convex-convex flat lens with positive refractive power, and the eleventh lens L11 is a convex-concave lens with positive refractive power.

[0181] The first lens L1 to the eleventh lens L11 are all spherical lenses; and the stop STO is arranged between the eighth lens L8 and the ninth lens L9.

[0182] Table 5 lists the related parameters of each lens in the optical lens of the present embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd of the material, and Abbe number Vd.

[0183]

[0184]

[0185] Table 5

[0186] In combination Figures 10 to 12 In addition, as shown in Table 1 and Table 5 above, in Example Four, the effective focal length F of the optical lens is 31 mm, the total optical length is 125 mm, and the F number Fno is 1.22.

[0187] The present Example Four is an optical lens having at least one of the following characteristics: large aperture (F1.2), infrared confocal, 2K high image quality, supporting dual optical path imaging and ranging, etc.

[0188] The above description is merely preferred embodiments of this application and variations thereof and is presented for the purpose of illustration only. Those skilled in the art will readily appreciate that the scope of the application is not limited to the specific combinations of technical features as described above and that the application is also applicable to other technical solutions that are obtained by any combination of the technical features disclosed herein or equivalent technical features without departing from the inventive concept. For example, the above technical features can be replaced with other technical features disclosed herein (but not limited to) that have similar functions to form a technical solution.

Claims

1. An optical lens, characterized in that, Along the optical axis from the object side to the image side, the directions include, in sequence: There are eleven lenses with optical power: a first lens (L1) with negative optical power, a second lens (L2) with negative optical power, a third lens (L3) with positive optical power, a fourth lens (L4) with negative optical power, a fifth lens (L5) with positive optical power, a sixth lens (L6) with negative optical power, a seventh lens (L7) with positive optical power, an eighth lens (L8) with negative optical power, a ninth lens (L9) with negative optical power, a tenth lens (L10) with positive optical power, and an eleventh lens (L11) with positive optical power. The total optical length (TTL) and back focal length (BFL) of the optical lens satisfy the following relationship: 2.5 ≤ TTL / BFL ≤ 2.

8.

2. The optical lens according to claim 1, characterized in that, The first lens (L1) is a convex-concave lens, the second lens (L2) is a concave-convex lens, the third lens (L3) is a convex-concave lens, the image-side surface of the fourth lens (L4) is concave, the image-side surface of the fifth lens (L5) is convex, the sixth lens (L6) is a concave-concave lens, the seventh lens (L7) is a convex-convex lens, and the eighth lens (L8) is a concave-convex lens.

3. The optical lens according to claim 1, characterized in that, The ninth lens (L9) is a convex-concave lens, the object side of the tenth lens (L10) is convex, and the object side of the eleventh lens (L11) is convex.

4. The optical lens according to claim 1, characterized in that, The fifth lens (L5) and the sixth lens (L6) together form the first cemented doublet lens.

5. The optical lens according to claim 1, characterized in that, The seventh lens (L7) and the eighth lens (L8) together form a second cemented doublet lens.

6. The optical lens according to claim 1, characterized in that, The ninth lens (L9) and the tenth lens (L10) together form a third cemented doublet lens.

7. The optical lens according to any one of claims 1-6, characterized in that, The maximum aperture (Dmax) of the optical lens and the total optical length (TTL) satisfy the following relationship: 0.3 ≤ Dmax / TTL ≤ 0.

4.

8. The optical lens according to any one of claims 1-6, characterized in that, The total optical length (TTL) and effective focal length (F) of the optical lens satisfy the following relationship: 4.0 ≤ TTL / F ≤ 4.

3.

9. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F1 of the first lens (L1) and the effective focal length F of the optical lens satisfy the following relationship: -5.4≤F1 / F≤-3.

0.

10. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F2 of the second lens (L2) and the effective focal length F of the optical lens satisfy the following relationship: -4.3≤F2 / F≤-3.

3.

11. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F3 of the third lens (L3) and the effective focal length F of the optical lens satisfy the following relationship: 1.2≤F3 / F≤2.

3.

12. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F4 of the fourth lens (L4) and the effective focal length F of the optical lens satisfy the following relationship: -1.7≤F4 / F≤-0.

7.

13. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F5 of the fifth lens (L5) and the effective focal length F of the optical lens satisfy the following relationship: 0.7≤F5 / F≤1.

7.

14. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F6 of the sixth lens (L6) and the effective focal length F of the optical lens satisfy the following relationship: -1.0≤F6 / F≤-0.

5.

15. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F7 of the seventh lens (L7) and the effective focal length F of the optical lens satisfy the following relationship: 0.85≤F7 / F≤1.

00.

16. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F8 of the eighth lens (L8) and the effective focal length F of the optical lens satisfy the following relationship: -2.6≤F8 / F≤-1.

7.

17. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F9 of the ninth lens (L9) and the effective focal length F of the optical lens satisfy the following relationship: -3.0≤F9 / F≤-1.

6.

18. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F10 of the tenth lens (L10) and the effective focal length F of the optical lens satisfy the following relationship: 1.0≤F10 / F≤2.

0.

19. The optical lens according to any one of claims 1-6, characterized in that, The effective focal length F11 of the eleventh lens (L11) and the effective focal length F of the optical lens satisfy the following relationship: 1.6≤F11 / F≤3.

2.

20. The optical lens according to any one of claims 1-6, characterized in that, The combined focal length Fa of the fifth lens (L5) and the sixth lens (L6) satisfies the following relationship with the effective focal length F of the optical lens: -4.2≤Fa / F≤-1.

3.

21. The optical lens according to any one of claims 1-6, characterized in that, The combined focal length Fb of the seventh lens (L7) and the eighth lens (L8) and the effective focal length F of the optical lens satisfy the following relationship: 1.3≤Fb / F≤1.

8.

22. The optical lens according to any one of claims 1-6, characterized in that, The combined focal length Fc of the ninth lens (L9) and the tenth lens (L10) and the effective focal length F of the optical lens satisfy the following relationship: 1.6≤Fc / F≤6.

0.

23. The optical lens according to any one of claims 1-6, characterized in that, The combined focal length FI of the first lens (L1) to the sixth lens (L6) and the effective focal length F of the optical lens satisfy the following relationship: -1.0≤FI / F≤-0.

5.

24. The optical lens according to any one of claims 1-6, characterized in that, The combined focal length FII of the seventh lens (L7) to the eleventh lens (L11) and the effective focal length F of the optical lens satisfy the following relationship: 0.6≤FII / F≤1.

0.

25. The optical lens according to any one of claims 1-6, characterized in that, The combined focal length FI of the first lens (L1) to the sixth lens (L6) and the combined focal length FII of the seventh lens (L7) to the eleventh lens (L11) satisfy the following relationship: -1.2≤FI / FII≤-0.

6.

26. The optical lens according to claim 1, characterized in that, The optical lens must meet at least one of the following conditions: 0.3≤Dmax / TTL≤0.4 4.0≤TTL / F≤4.1 2.55≤TTL / BFL≤2.75 -5.1≤F1 / F≤-3.3, -4.15≤F² / F≤-3.45 1.4≤F3 / F≤2.1 -1.5≤F4 / F≤-0.9, 0.9≤F5 / F≤1.3 -0.9≤F6 / F≤-0.6, 0.85≤F7 / F≤1.00 -2.4≤F8 / F≤-1.85, -2.85≤F9 / F≤-1.8, 1.2≤F10 / F≤1.8 1.8≤F11 / F≤3 -4≤Fa / F≤-1.48, 1.4≤Fb / F≤1.7 2≤Fc / F≤5.68, -0.85≤FI / F≤-0.65, 0.75≤FII / F≤0.9 -1.05≤FI / FII≤-0.8, Wherein, Dmax is the maximum aperture of the optical lens, TTL is the total optical length of the optical lens, F is the effective focal length of the optical lens, BFL is the back focal length of the optical lens, F1 is the effective focal length of the first lens (L1), F2 is the effective focal length of the second lens (L2), F3 is the effective focal length of the third lens (L3), F4 is the effective focal length of the fourth lens (L4), F5 is the effective focal length of the fifth lens (L5), F6 is the effective focal length of the sixth lens (L6), F7 is the effective focal length of the seventh lens (L7), and F8 is the effective focal length of the eighth lens (L8). Focal length: F9 is the effective focal length of the ninth lens (L9), F10 is the effective focal length of the tenth lens (L10), F11 is the effective focal length of the eleventh lens (L11), Fa is the combined focal length of the fifth lens (L5) and the sixth lens (L6), Fb is the combined focal length of the seventh lens (L7) and the eighth lens (L8), Fc is the combined focal length of the ninth lens (L9) and the tenth lens (L10), FI is the combined focal length of the first lens (L1) to the sixth lens (L6), and FII is the combined focal length of the seventh lens (L7) to the eleventh lens (L11).

Images