A long focal length and large target surface lens

Abstract

An embodiment of the present invention discloses a long-focus large-format lens. The lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a diaphragm, a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens sequentially arranged along the optical axis from the object side to the image side; the first lens, the fifth lens, the eighth lens, and the ninth lens have positive optical powers, the second lens, the sixth lens, the seventh lens, and the tenth lens have negative optical powers, and the lens group composed of the third lens and the fourth lens has a negative optical power, which can realize a fixed-focus lens with an aperture F < 2.1. The use of all-glass lenses can achieve stable performance at high and low temperatures, and can meet the usage conditions of -40°C to 80°C. At the same time, it has a large format and can be maximally matched with a 4 / 3″ format sensor chip, featuring day-night confocal, large format, and small purple fringing.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of optical lenses, and in particular, to a telephoto large-format lens. Background Art

[0002] In recent years, with the development of the security trend, surveillance lens technology has brought new changes to the networking of cameras. The most obvious changes in lenses are reflected in two aspects: high definition and large format. In the era of networking and digitization, the pursuit of high definition in surveillance has led to higher requirements for the size of the image sensor in cameras. Generally speaking, the larger the area of the photosensitive device, the better the photosensitive performance, the higher the signal-to-noise ratio, and the better the imaging effect. In order to improve the picture quality, high-definition network camera products often use large-format photosensitive chips. However, most of the fixed-focus lenses on the market currently cannot meet the requirements of large apertures and large formats, which is not conducive to the networking development of surveillance lenses. Summary of the Invention

[0003] The present invention provides a telephoto large-format lens, which has the characteristics of day-night confocal, large format, and small purple fringing, and can be maximally matched with a 4 / 3″ sensor chip.

[0004] Embodiments of the present invention provide a telephoto large-format lens, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a diaphragm, a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens arranged in sequence from the object side to the image side along the optical axis;

[0005] The first lens, the fifth lens, the eighth lens, and the ninth lens have positive optical powers, the second lens, the sixth lens, the seventh lens, and the tenth lens have negative optical powers, and the lens group composed of the third lens and the fourth lens has a negative optical power.

[0006] Optionally, the third lens and the fourth lens are cemented to form a first cemented lens group, and the third lens and the fourth lens have opposite optical powers.

[0007] Optionally, the seventh lens and the eighth lens are cemented to form a second cemented lens group, and the second cemented lens group has a positive or negative optical power.

[0008] Optionally, the object side surface of the first lens is convex and the image side surface is concave;

[0009] The object side surface of the second lens is convex and the image side surface is concave;

[0010] The object side surface of the third lens is concave or convex;

[0011] The object side surface of the fourth lens is convex or concave, and the image side surface is convex or concave;

[0012] The object side of the fifth lens is convex, and the image side is convex;

[0013] The object side of the sixth lens is concave or convex, and the image side is concave;

[0014] The object side of the seventh lens is concave or convex;

[0015] The object side of the eighth lens is convex, and the image side is convex;

[0016] The object side of the ninth lens is convex, and the image side is concave or convex;

[0017] The object side of the tenth lens is convex, and the image side is concave.

[0018] Optionally, the optical powers of the lenses in the long focal length large format lens satisfy the following conditions:

[0019] 0.19 < ψ1 / ψ < 0.49;

[0020] -0.55 < ψ2 / ψ < -0.2;

[0021] -1.29 < ψ3 / ψ < 0.14;

[0022] -1.40 < ψ4 / ψ < 0.67;

[0023] 1.12 < ψ5 / ψ < 1.36;

[0024] -0.87 < ψ6 / ψ < -0.39;

[0025] -1.26 < ψ7 / ψ < -0.04;

[0026] 0 < ψ8 / ψ < 0.59;

[0027] 0.67 < ψ9 / ψ < 1.09;

[0028] -0.74 < ψ10 / ψ < -0.12;

[0029] Wherein, ψ is the optical power of the long focal length large format lens, ψn is the optical power of the nth lens, and n takes an integer from 1 to 10.

[0030] Optionally, the first lens to the tenth lens are all glass spherical lenses.

[0031] Optionally, the refractive index nd and Abbe number vd of the lenses in the long focal length large format lens satisfy the following conditions:

[0032] 1.65 < L1_nd < 1.99, 15 < L1_vd < 41;

[0033] 1.40 < L2_nd < 1.54, 15 < L2_vd < 69;

[0034] 1.40 < L3_nd < 1.90, 15 < L3_vd < 95;

[0035] 1.47 < L4_nd < 1.84, 29 < L4_vd < 90;

[0036] 1.91 < L5_nd < 2.05, 15 < L5_vd < 63;

[0037] 1.51 < L6_nd < 1.69, 29 < L6_vd < 95;

[0038] 1.81 < L7_nd < 2.05, 15 < L7_vd < 31;

[0039] 1.56 < L8_nd < 1.79, 76 < L8_vd < 95;

[0040] 1.50 < L9_nd < 1.82, 15 < L9_vd < 20;

[0041] 1.65 < L10_nd < 2.05, 19 < L10_vd < 95;

[0042] Among them, Ln_nd is the refractive index of the nth lens, and Ln_vd is the Abbe number of the nth lens, where n is an integer from 1 to 10.

[0043] The long - focal - length large - image - plane lens provided by the embodiment of the present invention is configured by sequentially arranging a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a diaphragm, a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens along the optical axis from the object side to the image side; the first lens, the fifth lens, the eighth lens, and the ninth lens have positive optical power, the second lens, the sixth lens, the seventh lens, and the tenth lens have negative optical power, and the lens group composed of the third lens and the fourth lens has negative optical power, which can realize a fixed - focus lens with an aperture F < 2.1, having a large image plane, and can be maximally matched with a 4 / 3″ image - plane sensor chip, featuring a large image plane and little purple fringing. Description of the Drawings

[0044] Figure 1 It is a schematic structural diagram of a long - focal - length large - image - plane lens provided by the embodiment of the present invention;

[0045] Figure 2 It is Figure 1 the axial aberration curve diagram of the shown long - focal - length large - image - plane lens;

[0046] Figure 3 It is Figure 1Chromatic aberration curve graph of the long focal length and large target surface lens shown;

[0047] Figure 4 is a schematic structural diagram of a long focal length and large target surface lens provided in the second embodiment of the present invention;

[0048] Figure 5 is Figure 4 axial aberration curve graph of the long focal length and large target surface lens shown;

[0049] Figure 6 is Figure 4 chromatic aberration curve graph of the long focal length and large target surface lens shown;

[0050] Figure 7 is a schematic structural diagram of a long focal length and large target surface lens provided in the third embodiment of the present invention;

[0051] Figure 8 is Figure 7 axial aberration curve graph of the long focal length and large target surface lens shown;

[0052] Figure 9 is Figure 7 chromatic aberration curve graph of the long focal length and large target surface lens shown;

[0053] Figure 10 is a schematic structural diagram of a long focal length and large target surface lens provided in the fourth embodiment of the present invention;

[0054] Figure 11 is Figure 10 axial aberration curve graph of the long focal length and large target surface lens shown;

[0055] Figure 12 is Figure 10 chromatic aberration curve graph of the long focal length and large target surface lens shown. Detailed implementation manners

[0056] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings rather than all the structures.

[0057] Figure 1 is a schematic structural diagram of a long focal length and large target surface lens provided in the embodiment of the present invention, refer to Figure 1, the long focal length large format lens includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a diaphragm 20, a sixth lens 16, a seventh lens 17, an eighth lens 18, a ninth lens 19, and a tenth lens 110 arranged in sequence from the object side to the image side along the optical axis; the first lens 11, the fifth lens 15, the eighth lens 18, and the ninth lens 19 have positive optical powers, the second lens 12, the sixth lens 16, the seventh lens 17, and the tenth lens 110 have negative optical powers, and the lens group composed of the third lens 13 and the fourth lens 14 has a negative optical power.

[0058] It can be understood that the optical power is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam, which characterizes the ability of the optical system to deflect light rays. The greater the absolute value of the optical power, the stronger the bending ability of the light rays; the smaller the absolute value of the optical power, the weaker the bending ability of the light rays. When the optical power is positive, the refraction of the light rays is convergent; when the optical power is negative, the refraction of the light rays is divergent. As Figure 1 shown in the long focal length large format lens, setting the first lens 11 to have a positive optical power can increase the field of view of the entire lens using the first lens and obtain a larger image acquisition range. At the same time, setting the diaphragm 20 between the fifth lens 15 and the sixth lens 16, for the five lenses in front of the diaphragm, the first lens 11 and the fifth lens 15 have positive optical powers, and the second lens 12 and the lens group of the third lens 13 and the fourth lens 14 have negative optical powers, which can cause the light beam to converge, diverge, and converge again in sequence; for the five lenses behind the diaphragm, the sixth lens 16, the seventh lens 17, and the tenth lens 110 have negative optical powers, which can ensure that the light beam passing through the diaphragm diverges multiple times. From the above process of light beam convergence and divergence, it can be understood that the long focal length large format lens can diverge the light beam as much as possible, thereby realizing a large format.

[0059] In addition, it should be noted that in the lens combinations before and after the above diaphragm, not all lenses are set to have negative optical powers to achieve the purpose of increasing the format. Setting some lenses to have positive optical powers can enable the entire lens to cooperate with positive and negative optical powers, aiming to correct the aberration formed during the process of light beam convergence and divergence, so as to ensure the clarity of the final image while realizing a long focal length and large format. In addition, setting the diaphragm between the fifth lens 15 with positive optical power and the sixth lens 16 with negative optical power can correct the off-axis aberration using the diaphragm after the fifth lens 15 converges the light beam, and improve the axial chromatic aberration, etc.

[0060] The lens provided by the embodiment of the present invention sequentially arranges a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a diaphragm, a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens along the optical axis from the object side to the image side; the first lens, the fifth lens, the eighth lens, and the ninth lens have positive optical powers, the second lens, the sixth lens, the seventh lens, and the tenth lens have negative optical powers, and the lens group composed of the third lens and the fourth lens has a negative optical power, which can realize a fixed-focus lens with an aperture F < 2.1, has a large target surface, and can match a 4 / 3″ target surface sensor chip at most, and has the characteristics of a large target surface and less purple fringing.

[0061] Optionally, in the above embodiment, it can be set that the first lens to the tenth lens are all glass spherical lenses. Preparing the lens with glass, that is, using all-glass lenses, the imaging quality can be not affected by the ambient temperature, the performance can be stable at high and low temperatures, and the use conditions of -40°C - 80°C can be met, realizing the characteristic of day and night confocal.

[0062] In a specific embodiment, it is optional that the third lens 13 and the fourth lens 14 are glued together to form a first glued lens group 100, and the first glued lens group 100 has a negative optical power.

[0063] For the third lens 13 and the fourth lens 14, setting the surface types of their opposite surfaces to be the same and gluing them can reduce the air gap between the two lenses, can appropriately correct chromatic aberration, and can also improve field curvature and coma. While overall realizing the beam divergence effect, the imaging quality can be further optimized.

[0064] Furthermore, in a preferred embodiment, it can also be set that the seventh lens 17 and the eighth lens 18 are glued together to form a second glued lens group 200, and the second glued lens group 200 has a positive optical power or a negative optical power. Similarly, for the glued seventh lens 17 and eighth lens 18, it can also realize the improvement of chromatic aberration, field curvature, and coma, and further optimize the imaging quality.

[0065] Continue to refer to Figure 1 , on the basis of the above embodiment, it can be set that the object side surface of the first lens 11 is convex and the image side surface is concave; the object side surface of the second lens 12 is convex and the image side surface is concave; the object side surface of the third lens 13 is concave or convex; the object side surface of the fourth lens 14 is convex or concave and the image side surface is convex or concave; the object side surface of the fifth lens 15 is convex and the image side surface is convex; the object side surface of the sixth lens 16 is concave or convex and the image side surface is concave; the object side surface of the seventh lens 17 is concave or convex; the object side surface of the eighth lens 18 is convex and the image side surface is convex; the object side surface of the ninth lens 19 is convex and the image side surface is concave or convex; the object side surface of the tenth lens 110 is convex and the image side surface is concave.

[0066] Among them, since the third lens 13 and the fourth lens 14 are cemented, and the seventh lens 17 and the eighth lens 18 are cemented, the opposing surfaces of the two cemented lenses are actually the same in surface shape. The image side of the third lens 13 is actually equivalent to the object side of the fourth lens 14, and the image side of the seventh lens 17 is actually equivalent to the object side of the eighth lens 18.

[0067] Continuing to refer to Figure 1 , in this long focal length large format lens, the optical powers of the optional lenses satisfy the following conditions:

[0068] 0.19 < ψ1 / ψ < 0.49;

[0069] -0.55 < ψ2 / ψ < -0.2;

[0070] -1.29 < ψ3 / ψ < 0.14;

[0071] -1.40 < ψ4 / ψ < 0.67;

[0072] 1.12 < ψ5 / ψ < 1.36;

[0073] -0.87 < ψ6 / ψ < -0.39;

[0074] -1.26 < ψ7 / ψ < -0.04;

[0075] 0 < ψ8 / ψ < 0.59;

[0076] 0.67 < ψ9 / ψ < 1.09;

[0077] -0.74 < ψ10 / ψ < -0.12;

[0078] Among them, ψ is the optical power of the long focal length large format lens, ψn is the optical power of the nth lens, and n takes integers from 1 to 10.

[0079] The above optical power ranges of the lenses ensure that each lens has a relatively fixed beam divergence and convergence effect, and cooperate with each other in the optical path of the entire lens to effectively correct axial aberration and chromatic aberration. While achieving clear imaging of a large format, the aberration balance under high and low temperature conditions is ensured.

[0080] Furthermore, the refractive index nd and Abbe number vd of the lenses in this long focal length large format lens can be selected to satisfy the following conditions:

[0081] 1.65 < L1_nd < 1.99, 15 < L1_vd < 41;

[0082] 1.40 < L2_nd < 1.54, 15 < L2_vd < 69;

[0083] 1.40 < L3_nd < 1.90, 15 < L3_vd < 95;

[0084] 1.47 < L4_nd < 1.84, 29 < L4_vd < 90;

[0085] 1.91 < L5_nd < 2.05, 15 < L5_vd < 63;

[0086] 1.51 < L6_nd < 1.69, 29 < L6_vd < 95;

[0087] 1.81 < L7_nd < 2.05, 15 < L7_vd < 31;

[0088] 1.56 < L8_nd < 1.79, 76 < L8_vd < 95;

[0089] 1.50 < L9_nd < 1.82, 15 < L9_vd < 20;

[0090] 1.65 < L10_nd < 2.05, 19 < L10_vd < 95;

[0091] Among them, Ln_nd is the refractive index of the nth lens, and Ln_vd is the Abbe number of the nth lens, where n is an integer from 1 to 10.

[0092] It should be noted that in the above embodiments, the use of glass spherical lenses for the lenses is only an optional embodiment of the present invention. Those skilled in the art can understand that based on the requirements of various aberration corrections, designing and using aspherical lenses can achieve better aberration correction effects. On this basis, in order to reduce the difficulty of fabricating aspherical surfaces for glass lenses, plastic lenses can also be optionally used. Those skilled in the art can make selections by balancing the aberration correction effects and the advantages of the stable performance of glass lenses at different temperatures, and no limitations are imposed here. Moreover, the scheme of gluing the third lens and the fourth lens together and gluing the seventh lens and the eighth lens together is also only an optional scheme of the present invention. Those skilled in the art can also choose to separately arrange the third lens, the fourth lens, the seventh lens, and the eighth lens, that is, a certain distance is set between the third lens and the fourth lens, and a certain distance is set between the seventh lens and the eighth lens.

[0093] The following uses four specific embodiments to illustrate the above long-focus large-format lens. As Figure 1As shown, in the first embodiment, the long focal length large format lens includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a diaphragm 20, a sixth lens 16, a seventh lens 17, an eighth lens 18, a ninth lens 19, and a tenth lens 110 arranged in sequence from the object side to the image side along the optical axis; the first lens 11, the fifth lens 15, the eighth lens 18, and the ninth lens 19 have positive optical powers, the second lens 12, the sixth lens 16, the seventh lens 17, and the tenth lens 110 have negative optical powers, and the lens group composed of the third lens 13 and the fourth lens 14 has a negative optical power.

[0094] The third lens 13 and the fourth lens 14 are cemented to form a first cemented lens group 100, and the first cemented lens group 100 has a negative optical power. The seventh lens 17 and the eighth lens 18 are cemented to form a second cemented lens group 200, and the second cemented lens group 200 has a positive optical power or a negative optical power.

[0095] More specifically, in the first embodiment, the third lens 13 has a positive optical power, the fourth lens 14 has a negative optical power, and the optical power of the cemented lens group composed of the seventh lens 17 and the eighth lens 18 is positive.

[0096] In the first embodiment, the design values of each lens of the long focal length large format lens are shown in Table 1 below.

[0097] Table 1 shows a set of design values of the long focal length large format lens in the first embodiment of the present invention (f = 34.85 mm; aperture F2.08)

[0098]

[0099]

[0100] The surface numbers in Table 1 are numbered according to the surface order of each lens. Among them, "S1" represents the front surface of the first lens, "S2" represents the rear surface of the first lens, and so on; "STO" represents the diaphragm of the lens; the radius of curvature represents the degree of curvature of the lens surface, with the unit of millimeter. A positive value represents that the surface bends towards the image side, and a negative value represents that the surface bends towards the object side. Among them, "PL" represents that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface, with the unit of millimeter; the refractive index represents the ability of the material between the current surface and the next surface to deflect light. A space represents that the current position is air and the refractive index is 1; the Abbe number represents the dispersion characteristic of the material between the current surface and the next surface to light. A space represents that the current position is air; "ψ1" represents the optical power of the first lens, "ψ2" represents the optical power of the second lens, and so on.

[0101] Figure 2 is Figure 1Axial aberration curve of the long focal length and large image plane lens shown Figure 3 is Figure 1 the chromatic aberration curve of the long focal length and large image plane lens shown. According to Figure 2 it can be seen that the axial aberration of light rays with different wavelengths (0.436μm, 0.486μm, 0.588μm, 0.5656μm, and 0.850μm) in this long focal length and large image plane lens is not greater than 0.09mm. From Figure 3 it can be seen that the axial chromatic aberration generated by light rays with different wavelengths (0.436μm, 0.486μm, 0.588μm, 0.5656μm, and 0.850μm) is within ±5μm. Especially for the light ray with purple wavelength (0.436μm), its chromatic aberration is lower compared with the existing lens design, so as to achieve the effect of small purple edges for this large image plane lens. In summary, it can be known that the long focal length and large image plane provided in the first embodiment of the present invention can not only correct the axial aberration well, but also ensure that there is a small difference in the imaging chromatic aberration between infrared light and visible light, which is beneficial to realizing the confocal of visible light and infrared light and providing high-resolution and high-quality images.

[0102] Figure 4 is a schematic structural diagram of a long focal length and large image plane lens provided in the second embodiment of the present invention. Referring to Figure 4 , similarly, this long focal length and large image plane lens includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a diaphragm 20, a sixth lens 16, a seventh lens 17, an eighth lens 18, a ninth lens 19, and a tenth lens 110 arranged in sequence from the object side to the image side along the optical axis; the first lens 11, the fifth lens 15, the eighth lens 18, and the ninth lens 19 have positive optical power, the second lens 12, the sixth lens 16, the seventh lens 17, and the tenth lens 110 have negative optical power, and the lens group composed of the third lens 13 and the fourth lens 14 has negative optical power.

[0103] The third lens 13 and the fourth lens 14 are glued to form a first glued lens group 100, and the first glued lens group 100 has negative optical power. The seventh lens 17 and the eighth lens 18 are glued to form a second glued lens group 200, and the second glued lens group 200 has positive optical power or negative optical power.

[0104] More specifically, in this second embodiment, the third lens 13 has positive optical power, the fourth lens 14 has negative optical power, and the optical power of the glued lens group composed of the seventh lens 17 and the eighth lens 18 is positive.

[0105] In this second embodiment, the design values of each lens of the long focal length and large image plane lens are shown in Table 2 below.

[0106] Table 2 shows a set of design values (f = 34.85mm; aperture F2.08) of the long focal length and large image plane lens in the second embodiment of the present invention

[0107]

[0108]

[0109] Figure 5 is Figure 4 the axial aberration curve diagram of the long focal length and large image plane lens shown Figure 6 is Figure 4 the chromatic aberration curve diagram of the long focal length and large image plane lens shown. According to Figure 5 it can be known that the axial aberrations of light rays with different wavelengths (0.436μm, 0.486μm, 0.588μm, 0.5656μm, and 0.850μm) in this long focal length and large image plane lens are all not greater than 0.09mm. From Figure 6 it can be known that the axial chromatic aberrations generated by light rays with different wavelengths (0.436μm, 0.486μm, 0.588μm, 0.5656μm, and 0.850μm) are within ±5μm. Especially for the light ray with purple wavelength (0.436μm), its chromatic aberration has a lower chromatic aberration compared with the existing lens design, so as to achieve the effect of small purple fringing of this large image plane lens. In summary, it can be known that the long focal length and large image plane provided in the second embodiment of the present invention can not only correct the axial aberration better, but also ensure that there is a small difference in the imaging chromatic aberration between infrared light and visible light, which is beneficial to realizing the confocal of visible light and infrared light and providing high-resolution and high-quality images.

[0110] Figure 7 is a structural schematic diagram of a long focal length and large image plane lens provided in the third embodiment of the present invention. Referring to Figure 7 , similarly, this long focal length and large image plane lens includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a diaphragm 20, a sixth lens 16, a seventh lens 17, an eighth lens 18, a ninth lens 19, and a tenth lens 110 arranged in sequence from the object side to the image side along the optical axis; the first lens 11, the fifth lens 15, the eighth lens 18, and the ninth lens 19 have positive optical powers, the second lens 12, the sixth lens 16, the seventh lens 17, and the tenth lens 110 have negative optical powers, and the lens group composed of the third lens 13 and the fourth lens 14 has a negative optical power.

[0111] The third lens 13 and the fourth lens 14 are glued to form a first glued lens group 100, and the first glued lens group 100 has a negative optical power. The seventh lens 17 and the eighth lens 18 are glued to form a second glued lens group 200, and the second glued lens group 200 has a positive optical power or a negative optical power.

[0112] More specifically, in the third embodiment, the third lens 13 has a positive optical power, the fourth lens 14 has a negative optical power, and the optical power of the cemented lens group composed of the seventh lens 17 and the eighth lens 18 is negative.

[0113] In the third embodiment, the design values of the lenses of the long focal length large format lens are shown in Table 3 below.

[0114] Table 3 shows a set of design values of the long focal length large format lens according to the third embodiment of the present invention (f = 34.85 mm; aperture F2.095)

[0115]

[0116]

[0117] Figure 8 Yes Figure 7 is the axial aberration curve graph of the long focal length large format lens shown, Figure 9 Yes Figure 7 is the chromatic aberration curve graph of the long focal length large format lens shown. According to Figure 8 it can be seen that the axial aberrations of different wavelength lights (0.436 μm, 0.486 μm, 0.588 μm, 0.5656 μm, and 0.850 μm) in the long focal length large format lens are not greater than 0.09 mm. From Figure 9 it can be seen that the axial chromatic aberrations generated by different wavelength lights (0.436 μm, 0.486 μm, 0.588 μm, 0.5656 μm, and 0.850 μm) are within ±5 μm. In particular, for the purple wavelength (0.436 μm) light, its chromatic aberration is lower compared with the existing lens designs, so that the effect of small purple fringes of the large format lens can be achieved. In summary, it can be known that the long focal length large format lens provided by the third embodiment of the present invention can not only correct the axial aberration well, but also ensure that there is a small difference in the imaging chromatic aberration between infrared light and visible light, which is beneficial to realizing the confocal of visible light and infrared light and providing high-resolution and high-quality images.

[0118] Figure 10 is a schematic structural diagram of a long focal length large format lens provided by the fourth embodiment of the present invention. Referring to Figure 10 , similarly, the long focal length large format lens includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a diaphragm 20, a sixth lens 16, a seventh lens 17, an eighth lens 18, a ninth lens 19, and a tenth lens 110 arranged in sequence from the object side to the image side along the optical axis; the first lens 11, the fifth lens 15, the eighth lens 18, and the ninth lens 19 have positive optical powers, the second lens 12, the sixth lens 16, the seventh lens 17, and the tenth lens 110 have negative optical powers, and the lens group composed of the third lens 13 and the fourth lens 14 has a negative optical power.

[0119] The third lens 13 and the fourth lens 14 are cemented to form the first cemented lens group 100, and the first cemented lens group 100 has a negative optical power. The seventh lens 17 and the eighth lens 18 are cemented to form the second cemented lens group 200, and the second cemented lens group 200 has a positive optical power or a negative optical power.

[0120] More specifically, in the fourth embodiment, the third lens 13 has a negative optical power, the fourth lens 14 has a positive optical power, and the optical power of the cemented lens group composed of the seventh lens 17 and the eighth lens 18 is positive.

[0121] In the fourth embodiment, the design values of each lens of the long focal length large format lens are shown in Table 4 below.

[0122] Table 4 shows a set of design values of the long focal length large format lens according to the fourth embodiment of the present invention (f = 34.85 mm; aperture F2.08)

[0123]

[0124]

[0125] Figure 11 Yes Figure 10 is the axial aberration curve diagram of the long focal length large format lens shown, Figure 12 is Figure 10 the chromatic aberration curve diagram of the long focal length large format lens shown. According to Figure 11 it can be seen that the axial aberrations of light rays with different wavelengths (0.436 μm, 0.486 μm, 0.588 μm, 0.5656 μm, and 0.850 μm) in the long focal length large format lens are not greater than 0.1 mm. From Figure 12 it can be seen that the axial chromatic aberrations generated by light rays with different wavelengths (0.436 μm, 0.486 μm, 0.588 μm, 0.5656 μm, and 0.850 μm) are within ±6 μm. In particular, for light rays with a purple wavelength (0.436 μm), the chromatic aberration is lower compared with the existing lens designs, so that the effect of small purple fringes of the large format lens can be achieved. In summary, it can be seen that the long focal length large format lens provided in the fourth embodiment of the present invention can not only correct the axial aberration well, but also ensure that there is a small difference in the imaging chromatic aberration between infrared light and visible light, which is beneficial to achieving confocal of visible light and infrared light and providing high-resolution and high-quality images.

[0126] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A long focal length large target surface lens, characterized in that, It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a diaphragm, a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens arranged in sequence from the object side to the image side along the optical axis; The first lens, the fifth lens, the eighth lens, and the ninth lens have positive optical powers, the second lens, the sixth lens, the seventh lens, and the tenth lens have negative optical powers, and the lens group composed of the third lens and the fourth lens has a negative optical power; The third lens and the fourth lens are cemented to form a first cemented lens group, and the third lens and the fourth lens have opposite optical powers; The seventh lens and the eighth lens are cemented to form a second cemented lens group, and the second cemented lens group has a positive or negative optical power; The object side surface of the first lens is convex and the image side surface is concave; The object side surface of the second lens is convex and the image side surface is concave; The object side surface of the third lens is concave or convex; The object side surface of the fourth lens is convex or concave, and the image side surface is convex or concave; The object side surface of the fifth lens is convex and the image side surface is convex; The object side surface of the sixth lens is concave or convex, and the image side surface is concave; The object side surface of the seventh lens is concave or convex; The object side surface of the eighth lens is convex and the image side surface is convex; The object side surface of the ninth lens is convex, and the image side surface is concave or convex; The object side surface of the tenth lens is convex and the image side surface is concave; The optical powers of the lenses in the long focal length large format lens satisfy the following conditions: 0.19 < ψ1 / ψ < 0.49; -0.55 < ψ2 / ψ < -0.2; -1.29 < ψ3 / ψ < 0.14; -1.40 < ψ4 / ψ < 0.67; 1.12 < ψ5 / ψ < 1.36; -0.87 < ψ6 / ψ < -0.39; -1.26 < ψ7 / ψ < -0.04; 0 < ψ8 / ψ < 0.59; 0.67 < ψ9 / ψ < 1.09; -0.74 < ψ10 / ψ < -0.12; Wherein, ψ is the optical power of the long focal length large format lens, ψn is the optical power of the nth lens, and n takes an integer from 1 to 10.

2. The telephoto large image circle lens according to claim 1, wherein The first lens to the tenth lens are all glass spherical lenses.

3. The telephoto large image circle lens according to claim 2, wherein, The refractive indices nd and Abbe numbers vd of the lenses in the long focal length large format lens satisfy the following conditions: 1.65 < L1_nd < 1.99, 15 < L1_vd < 41; 1.40 < L2_nd < 1.54, 15 < L2_vd < 69; 1.40 < L3_nd < 1.90, 15 < L3_vd < 95; 1.47 < L4_nd < 1.84, 29 < L4_vd < 90; 1.91 < L5_nd < 2.05, 15 < L5_vd < 63; 1.51 < L6_nd < 1.69, 29 < L6_vd < 95; 1.81 < L7_nd < 2.05, 15 < L7_vd < 31; 1.56 < L8_nd < 1.79, 76 < L8_vd < 95; 1.50 < L9_nd < 1.82, 15 < L9_vd < 20; 1.65 < L10_nd < 2.05, 19 < L10_vd < 95; Wherein, Ln_nd is the refractive index of the nth lens, Ln_vd is the Abbe number of the nth lens, and n is an integer from 1 to 10.

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