Optical lens

Abstract

The optical lens comprises a first lens group, a second lens group and a third lens group which are sequentially arranged from an object plane to an image plane along an optical axis, and the first lens group comprises a first lens, a second lens and a third lens and is used for enlarging the light beam size of the object plane; the second lens group comprises at least one group of balsaming lenses, comprises a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens, and is used for shaping the light beam; and the third lens group comprises a thirteenth lens, a fourteenth lens, a fifteenth lens, a sixteenth lens and a seventeenth lens and is used for focusing the light beams. According to the technical scheme, the number of the lens groups included in the optical lens and the number of the lenses included in each lens group are reasonably set, so that clear imaging within the wavelength range of 550-850 nm can be realized, and the total optical length range of the lens is relatively small. Moreover, the second lens group comprises at least one group of balsaming lenses, so that the imaging chromatic aberration can be reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of optical devices, and in particular to an optical lens. Background Art

[0002] In order to identify the mark points on the surface of the workpiece, a camera and a recognition lens are required. Different plates have different reflectivity to light of different wavelengths. The reflectivity determines the recognition accuracy of the camera. For example, the suitable wavelength for solder mask ink plates is 850nm, and the suitable wavelength for ordinary circuit boards is 550nm~650nm. In order to clearly identify the mark points, detection light sources with different wavelengths are required. The detection light source is irradiated on the board, and the board reflects light to the recognition lens, which is then imaged on the camera.

[0003] In the above process, light of different wavelengths needs to pass through the recognition lens, and the traditional recognition lens will have dispersion when receiving light of different wavelengths. Therefore, it is necessary to design a recognition lens that can avoid chromatic aberration. In addition, due to the height limit of the machine, the distance from the object distance to the image distance of the recognition object is relatively small, so the total length of the lens design should be as short as possible. Summary of the invention

[0004] The present invention provides an optical lens, which can match different wavelengths, has small chromatic aberration and has a small total length by reasonably setting the composition of the lens and the bonding method between the lenses.

[0005] An embodiment of the present invention provides an optical lens, comprising a first lens group, a second lens group, and a third lens group arranged in sequence from an object plane to an image plane along an optical axis;

[0006] The first lens group includes a first lens, a second lens and a third lens; the second lens group includes at least one group of cemented lenses, and includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens; the third lens group includes a thirteenth lens, a fourteenth lens, a fifteenth lens, a sixteenth lens and a seventeenth lens;

[0007] The first lens group is used to enlarge the light beam size of the object plane, the second lens group is used to shape the light beam, and the third lens group is used to focus the light beam.

[0008] Optionally, the fourth lens and the fifth lens are cemented together, the sixth lens, the seventh lens, the eighth lens and the ninth lens are cemented together, and the tenth lens, the eleventh lens and the twelfth lens are cemented together.

[0009] Optionally, the first lens includes a first object-side surface close to the object plane and a first image-side surface close to the image plane, the first object-side surface is a concave surface, and the first image-side surface is a convex surface;

[0010] The second lens comprises a second object-side surface close to the object plane and a second image-side surface close to the image plane, the second object-side surface is a concave surface, and the second image-side surface is a convex surface;

[0011] The third lens comprises a third object-side surface close to the object plane and a third image-side surface close to the image plane, the third object-side surface is a convex surface, and the third image-side surface is a convex surface;

[0012] The fourth lens comprises a fourth object-side surface close to the object plane and a fourth image-side surface close to the image plane, the fourth object-side surface is a convex surface, and the fourth image-side surface is a convex surface;

[0013] The fifth lens comprises a fifth object-side surface close to the object plane and a fifth image-side surface close to the image plane, the fifth object-side surface is a concave surface, and the fifth image-side surface is a concave surface;

[0014] The sixth lens comprises a sixth object-side surface close to the object plane and a sixth image-side surface close to the image plane, the sixth object-side surface is a convex surface, and the sixth image-side surface is a concave surface;

[0015] The seventh lens comprises a seventh object-side surface close to the object plane and a seventh image-side surface close to the image plane, the seventh object-side surface is a convex surface, and the seventh image-side surface is a convex surface;

[0016] The eighth lens comprises an eighth object-side surface close to the object plane and an eighth image-side surface close to the image plane, the eighth object-side surface is a concave surface, and the eighth image-side surface is a concave surface;

[0017] The ninth lens comprises a ninth object-side surface close to the object plane and a ninth image-side surface close to the image plane, the ninth object-side surface is a convex surface, and the ninth image-side surface is a convex surface;

[0018] The tenth lens comprises a tenth object-side surface close to the object plane and a tenth image-side surface close to the image plane, the tenth object-side surface is a convex surface, and the tenth image-side surface is a convex surface;

[0019] The eleventh lens comprises an eleventh object-side surface close to the object plane and an eleventh image-side surface close to the image plane, the eleventh object-side surface is a concave surface, and the eleventh image-side surface is a concave surface;

[0020] The twelfth lens comprises a twelfth object-side surface close to the object plane and a twelfth image-side surface close to the image plane, the twelfth object-side surface is a convex surface, and the twelfth image-side surface is a concave surface;

[0021] The thirteenth lens comprises a thirteenth object-side surface close to the object plane and a thirteenth image-side surface close to the image plane, the thirteenth object-side surface is a convex surface, and the thirteenth image-side surface is a convex surface;

[0022] The fourteenth lens comprises a fourteenth object-side surface close to the object plane and a fourteenth image-side surface close to the image plane, the fourteenth object-side surface is a convex surface, and the fourteenth image-side surface is a concave surface;

[0023] The fifteenth lens comprises a fifteenth object-side surface close to the object plane and a fifteenth image-side surface close to the image plane, the fifteenth object-side surface is a convex surface, and the fifteenth image-side surface is a concave surface;

[0024] The sixteenth lens comprises a sixteenth object-side surface close to the object plane and a sixteenth image-side surface close to the image plane, the sixteenth object-side surface is a concave surface, and the sixteenth image-side surface is a concave surface;

[0025] The seventeenth lens includes a seventeenth object-side surface close to the object plane and a seventeenth image-side surface close to the image plane. The seventeenth object-side surface is a convex surface, and the seventeenth image-side surface is a convex surface.

[0026] Optionally, a radius of curvature of the first object-side surface is R11, and a radius of curvature of the first image-side surface is R12, wherein 7 mm < R11 < 9 mm, and 10 mm < R12 < 14 mm;

[0027] The curvature radius of the second object-side surface is R21, and the curvature radius of the second image-side surface is R22, wherein 24 mm < R21 < 30 mm, and 14 mm < R22 < 18 mm;

[0028] The curvature radius of the third object-side surface is R31, and the curvature radius of the third image-side surface is R32, wherein 65 mm < R31 < 75 mm, and 56 mm < R32 < 66 mm;

[0029] The curvature radius of the fourth object-side surface is R41, and the curvature radius of the fourth image-side surface is R42, wherein 26 mm < R41 < 30 mm, and 20 mm < R42 < 30 mm;

[0030] The curvature radius of the fifth object-side surface is R51, and the curvature radius of the fifth image-side surface is R52, wherein 20 mm < R51 < 30 mm, and 22 mm < R52 < 28 mm;

[0031] The curvature radius of the sixth object-side surface is R61, and the curvature radius of the sixth image-side surface is R62, wherein 50 mm < R61 < 60 mm, and 17 mm < R62 < 22 mm;

[0032] The curvature radius of the seventh object-side surface is R71, and the curvature radius of the seventh image-side surface is R72, wherein 17 mm < R71 < 22 mm, and 13 mm < R72 < 23 mm;

[0033] The curvature radius of the eighth object-side surface is R81, and the curvature radius of the eighth image-side surface is R82, wherein 13 mm < R81 < 23 mm, and 19 mm < R82 < 28 mm;

[0034] The curvature radius of the ninth object-side surface is R91, and the curvature radius of the ninth image-side surface is R92, wherein 19 mm < R91 < 28 mm, and 28 mm < R92 < 34 mm;

[0035] The curvature radius of the tenth object-side surface is R101, and the curvature radius of the tenth image-side surface is R102, wherein 19 mm < R101 < 23 mm, and 75 mm < R102 < 85 mm;

[0036] The curvature radius of the eleventh object-side surface is R111, and the curvature radius of the eleventh image-side surface is R112, wherein 75 mm < R111 < 85 mm, and 13 mm < R112 < 18 mm;

[0037] The curvature radius of the twelfth object side surface is R121, and the curvature radius of the twelfth image side surface is R122, wherein 13 mm < R121 < 18 mm, and 54 mm < R122 < 62 mm;

[0038] The curvature radius of the thirteenth object-side surface is R131, and the curvature radius of the thirteenth image-side surface is R132, wherein 51 mm < R131 < 61 mm, and 40 mm < R132 < 50 mm;

[0039] The curvature radius of the fourteenth object side surface is R141, and the curvature radius of the fourteenth image side surface is R142, wherein 17 mm < R141 < 21 mm, and 11 mm < R142 < 15 mm;

[0040] The curvature radius of the fifteenth object side surface is R151, and the curvature radius of the fifteenth image side surface is R152, wherein 13 mm < R151 < 17 mm, and 12 mm < R152 < 14 mm;

[0041] The curvature radius of the sixteenth object-side surface is R161, and the curvature radius of the sixteenth image-side surface is R162, wherein 12 mm < R161 < 14 mm, and 22 mm < R162 < 32 mm;

[0042] The curvature radius of the seventeenth object side surface is R171, and the curvature radius of the seventeenth image side surface is R172, wherein 30 mm<R171<36 mm, and 120 mm<R172<135 mm.

[0043] Optionally, a distance between the third image-side surface and the fourth object-side surface on the optical axis is L1, wherein 10 mm ≤ L1 ≤ 19 mm;

[0044] And / or, a distance between the fifth image-side surface and the sixth object-side surface on the optical axis is L2, wherein 0.5 mm ≤ L2 ≤ 3 mm.

[0045] Optionally, a distance between the twelfth image-side surface and the thirteenth object-side surface on the optical axis is L3, wherein 12 mm ≤ L3 ≤ 14 mm;

[0046] The distance between the fourteenth image-side surface and the fifteenth object-side surface on the optical axis is L4, where 0 mm < L4 ≤ 2 mm;

[0047] The distance between the fifteenth image-side surface and the sixteenth object-side surface on the optical axis is L5, where 4 mm ≤ L5 ≤ 6 mm;

[0048] A distance between the sixteenth image-side surface and the seventeenth object-side surface on the optical axis is L6, wherein 6 mm ≤ L6 ≤ 8 mm.

[0049] Optionally, the refractive index of the first lens is n1, wherein 1.85<n1<1.95;

[0050] The refractive index of the second lens is n2, wherein 1.8<n2<1.95;

[0051] The refractive index of the third lens is n3, wherein 1.75<n3<1.8;

[0052] The refractive index of the fourth lens is n4, wherein 1.55<n4<1.65;

[0053] The refractive index of the fifth lens is n5, wherein 1.51<n5<1.65;

[0054] The refractive index of the sixth lens is n6, wherein 1.8<n6<1.9;

[0055] The refractive index of the seventh lens is n7, wherein 1.6<n7<1.65;

[0056] The refractive index of the eighth lens is n8, wherein 1.8<n8<1.9;

[0057] The refractive index of the ninth lens is n9, wherein 1.6<n9<1.65;

[0058] The refractive index of the tenth lens is n10, wherein 1.6<n10<1.65;

[0059] The refractive index of the eleventh lens is n11, wherein 1.8<n11<1.95;

[0060] The refractive index of the twelfth lens is n12, wherein 1.6<n12<1.65;

[0061] The refractive index of the thirteenth lens is n13, wherein 1.8<n13<1.95;

[0062] The refractive index of the fourteenth lens is n14, wherein 1.6<n14<1.7;

[0063] The refractive index of the fifteenth lens is n15, wherein 1.7<n15<1.8;

[0064] The refractive index of the sixteenth lens is n16, wherein 1.4<n16<1.5;

[0065] The refractive index of the seventeenth lens is n17, wherein 1.85<n17<2.

[0066] Optionally, the optical focal power of the first lens is negative, the optical focal power of the second lens is positive, the optical focal power of the third lens is positive, the optical focal power of the fourth lens is positive, the optical focal power of the fifth lens is negative, the optical focal power of the sixth lens is negative, the optical focal power of the seventh lens is positive or negative, the optical focal power of the eighth lens is negative, the optical focal power of the ninth lens is positive, the optical focal power of the tenth lens is positive, the optical focal power of the eleventh lens is negative, the optical focal power of the twelfth lens is positive or negative, the optical focal power of the thirteenth lens is positive, the optical focal power of the fourteenth lens is negative or positive, the optical focal power of the fifteenth lens is positive or negative, the optical focal power of the sixteenth lens is negative, and the optical focal power of the seventeenth lens is positive.

[0067] Optionally, the optical system further includes an aperture, and the aperture is located in the optical path between the ninth lens and the tenth lens.

[0068] Optionally, the total optical length of the optical lens is TTL, where TTL is less than 150 mm.

[0069] The optical lens provided by the embodiment of the present invention includes a first lens group, a second lens group and a third lens group, wherein the first lens group further includes a first lens, a second lens and a third lens, and the first lens group is used to magnify the light spot on the object side to a suitable size. The second lens group includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens, and the second lens group is used to achieve light shaping to ensure that light from different directions at a certain point on the object surface can converge into a point on the image plane; and the second lens group includes at least one group of cemented lenses, so that chromatic aberration can be reduced or eliminated. The third lens group includes a thirteenth lens, a fourteenth lens, a fifteenth lens, a sixteenth lens and a seventeenth lens, and the third lens group is used to shrink the light beam so that the light spot can match the image plane to achieve a focusing effect to ensure good imaging. In addition, the setting of seventeen lenses can ensure that a single lens bears less optical power and correspondingly less aberration, so that the entire optical length can be compressed to achieve an optical system with a smaller optical length.

[0070] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0072] Figure 1 is a schematic structural diagram of an optical lens provided in Embodiment 1 of the present invention;

[0073] Figure 2 Schematic diagram of an MTF curve of an optical lens provided in Embodiment 1 of the present invention;

[0074] Figure 3 is a schematic diagram of a distortion curve of an optical lens provided in Embodiment 1 of the present invention;

[0075] Figure 4 is a schematic diagram of a vertical axis chromatic aberration curve of an optical lens provided in Embodiment 1 of the present invention;

[0076] Figure 5 is a schematic structural diagram of an optical lens provided by Embodiment 2 of the present invention;

[0077] Figure 6is a schematic diagram of an MTF curve of an optical lens provided in Embodiment 2 of the present invention;

[0078] Figure 7 is a schematic diagram of a distortion curve of an optical lens provided in Embodiment 2 of the present invention;

[0079] Figure 8 It is a schematic diagram of a vertical axis chromatic aberration curve of an optical lens provided in Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0080] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0081] Embodiment 1

[0082] Figure 1 is a schematic diagram of the structure of an optical lens provided in Embodiment 1 of the present invention, such as Figure 1 As shown, the optical lens provided in the first embodiment of the present invention comprises a first lens group S1, a second lens group S2 and a third lens group S3 which are arranged in sequence from the object plane to the image plane along the optical axis; the first lens group S1 comprises a first lens 101, a second lens 102 and a third lens 103; the second lens group comprises at least one group of cemented lenses, and comprises a fourth lens 104, a fifth lens 105, a sixth lens 106, a seventh lens 107, an eighth lens 108, a ninth lens 109, a tenth lens 110, an eleventh lens 111 and a twelfth lens 112; the third lens group S3 comprises a thirteenth lens 113, a fourteenth lens 114, a fifteenth lens 115, a sixteenth lens 116 and a seventeenth lens 117; the first lens group S1 is used to enlarge the light beam size of the object plane, the second lens group S2 is used to shape the light beam, and the third lens group S3 is used to focus the light beam.

[0083] Specifically, the optical lens provided in the embodiment of the present invention includes three lens groups with a total of seventeen lenses, wherein the first lens group S1 includes a first lens 101, a second lens 102 and a third lens 103. The function of the first lens group S1 is to magnify the light spot on the object side to a suitable size to ensure that the light beam entering the second lens group S2 has a suitable light spot size, so as to facilitate light shaping of the light beam in the second lens group S2.

[0084] The second lens group S2 includes a fourth lens 104, a fifth lens 105, a sixth lens 106, a seventh lens 107, an eighth lens 108, a ninth lens 109, a tenth lens 110, an eleventh lens 111 and a twelfth lens 112. The second lens group S2 has a large number of lenses, that is, the time limit of light shaping in the second lens group S2 depends on multiple lenses to be realized together. In this way, the second lens group S2 can avoid a large range of adjustment of the light output angle between two adjacent lenses on the basis of realizing light shaping, that is, the light beam can be transmitted relatively smoothly between the two adjacent lenses, so that the distortion caused by the large range of adjustment of the light output angle can be avoided, and a good imaging effect can be achieved on the basis of realizing light shaping. Further, the second lens group S2 includes at least one group of cemented lenses. The cemented lenses can be understood as two lenses arranged adjacent to each other in the optical path, where the image side of the front lens is cemented with the object side of the rear lens. The setting of the cemented lenses can minimize or eliminate chromatic aberration. The use of cemented lenses in optical imaging systems can improve image quality and reduce reflection loss of light energy, thereby improving image quality and enhancing the clarity of lens imaging. In addition, the setting of the cemented lenses can eliminate the air gap between two or more lenses that are glued to each other, which helps to reduce the total optical length of the lens, and can also reduce the tolerance sensitivity problems such as tilt / eccentricity generated during the assembly process of the optical lens, simplify the assembly procedure during the lens manufacturing process, and improve equipment efficiency. Further, the setting of the cemented lenses can also reduce the light loss caused by reflection between lenses, improve illumination, and reduce the risk of ghosting. Furthermore, since the second lens group S2 includes more lenses, the arrangement of the cemented lenses can have a variety of different forms, such as a double cemented lens, a triple cemented lens or a quadruple cemented lens. The chromatic aberration can be further corrected or eliminated by arranging a variety of different cemented lens arrangements to improve the imaging quality.

[0085] The third lens group S3 includes a thirteenth lens 113, a fourteenth lens 114, a fifteenth lens 115, a sixteenth lens 116 and a seventeenth lens 117. The third lens group S3 mainly shrinks the light beam so that the light spot can match the image plane; at the same time, the focusing and clear imaging effects are achieved.

[0086] Furthermore, in a given optical system, the total focal length is a quantitative value, and the distribution of focal length in different lenses is essentially the distribution of the total focal length in the optical system. The amount of focal length distribution directly determines the amount of aberration of a single lens. Fewer lenses means that the focal length of a single lens must be distributed more, and at the same time, the aberration will be distributed more. In this way, only a long focal length optical system can be used to reduce the aberration by reducing the angle of light change, so the overall optical length will be lengthened. In an embodiment of the present invention, the optical system is arranged to include seventeen lenses. Under the premise of more lens settings, the average focal length of a single lens is less, and the corresponding aberration is also less. The aberration with large light angle changes can also be shared by more lenses. In this way, it can be ensured that the entire optical length can be compressed, and an optical system with a smaller total optical length can be realized to meet the distance limit between the specific object distance and the image distance due to the height limit of the machine.

[0087] In summary, the optical system provided by the embodiment of the present invention can realize an optical lens with a short total optical length and small chromatic aberration by reasonably setting the number of lens groups, the number of lenses, and the bonding conditions of the lenses, thereby ensuring that imaging requirements are met.

[0088] On the basis of the above embodiment, the total optical length of the optical lens is TTL, wherein TTL<150 mm, for example, it may be 123.55 mm, thereby ensuring that an optical lens with a shorter total optical length can be realized.

[0089] Furthermore, the optical lens provided in the embodiment of the present invention may have an object-space resolution of 1 μm, which has a relatively high resolution.

[0090] Based on the above embodiments, continue to refer to Figure 1 As shown, the fourth lens 104 and the fifth lens 105 are cemented together, the sixth lens 106, the seventh lens 107, the eighth lens 108 and the ninth lens 109 are cemented together, and the tenth lens 110, the eleventh lens 111 and the twelfth lens 112 are cemented together.

[0091] like Figure 1As shown, the cementing arrangement of the fourth lens 104 and the fifth lens 105 can be understood as the image side surface of the fourth lens 104 being cemented with the object side surface of the fifth lens 105, thereby forming a double cemented lens. The cementing arrangement of the sixth lens 106, the seventh lens 107, the eighth lens 108 and the ninth lens 109 can be understood as the image side surface of the sixth lens 106 being cemented with the object side surface of the seventh lens 107, the image side surface of the seventh lens 107 being cemented with the object side surface of the eighth lens 108, and the image side surface of the eighth lens 108 being cemented with the object side surface of the ninth lens 109, thereby forming a quadruple cemented lens. The cementing arrangement of the tenth lens 110, the eleventh lens 111 and the twelfth lens 112 can be understood as the image side surface of the tenth lens 110 being cemented with the object side surface of the eleventh lens 111, and the image side surface of the eleventh lens 111 being cemented with the object side surface of the twelfth lens 112, thereby forming a triple cemented lens. By arranging doublets, triplets and quadruplets of lenses, chromatic aberration can be further reduced or eliminated to ensure imaging quality.

[0092] Based on the above embodiments, continue to refer to Figure 1 As shown, the optical lens provided by the embodiment of the present invention may further include a stop STO, and the stop STO is located in the optical path between the ninth lens 109 and the tenth lens 110 .

[0093] Specifically, the aperture STO is arranged in the optical path of the optical lens, which can effectively reduce the aperture size of the lens in front of the aperture STO and reduce the weight of the lens on the one hand; on the other hand, it is conducive to reducing the aperture FNO value and realizing a large aperture design. In addition, the aperture STO is located in the optical path between the ninth lens 109 and the tenth lens 110, that is, in the optical path after the aperture STO, a triplet lens formed by the tenth lens 110, the eleventh lens 111 and the twelfth lens 112 is arranged, which can ensure that the uniform energy light after passing through the aperture STO does not have chromatic aberration, that is, avoids the formation of chromatic aberration again after the light of uniform brightness is emitted.

[0094] On the basis of the above embodiments, the first lens 101 includes a first object-side surface close to the object plane and a first image-side surface close to the image plane, the first object-side surface is a concave surface, and the first image-side surface is a convex surface; the second lens 102 includes a second object-side surface close to the object plane and a second image-side surface close to the image plane, the second object-side surface is a concave surface, and the second image-side surface is a convex surface; the third lens 103 includes a third object-side surface close to the object plane and a third image-side surface close to the image plane, the third object-side surface is a convex surface, and the third image-side surface is a convex surface; the fourth lens 104 includes a fourth object-side surface close to the object plane and a fourth image-side surface close to the image plane, the fourth object-side surface is a convex surface, and the fourth image-side surface is a convex surface; the fifth lens 105 includes a second object-side surface close to the object plane and a second image-side surface close to the image plane, the second object-side surface is a concave surface, and the second image-side surface is a convex surface. The fifth object side surface is on the side close to the image plane and the fifth image side surface is on the side close to the image plane, the fifth object side surface is concave, and the fifth image side surface is concave; the sixth lens 106 includes a sixth object side surface on the side close to the object plane and a sixth image side surface on the side close to the image plane, the sixth object side surface is convex, and the sixth image side surface is concave; the seventh lens 107 includes a seventh object side surface on the side close to the object plane and a seventh image side surface on the side close to the image plane, the seventh object side surface is convex, and the seventh image side surface is convex; the eighth lens 108 includes an eighth object side surface on the side close to the object plane and an eighth image side surface on the side close to the image plane, the eighth object side surface is concave, and the eighth image side surface is concave; the ninth lens 109 includes a ninth object side surface on the side close to the object plane and a ninth image side surface on the side close to the image plane, the ninth object side surface is The side surfaces are convex, and the ninth image side surface is convex; the tenth lens 110 includes a tenth object side surface close to the object plane and a tenth image side surface close to the image plane, the tenth object side surface is convex, and the tenth image side surface is convex; the eleventh lens 111 includes an eleventh object side surface close to the object plane and an eleventh image side surface close to the image plane, the eleventh object side surface is concave, and the eleventh image side surface is concave; the twelfth lens 112 includes a twelfth object side surface close to the object plane and a twelfth image side surface close to the image plane, the twelfth object side surface is convex, and the twelfth image side surface is concave; the thirteenth lens 113 includes a thirteenth object side surface close to the object plane and a thirteenth image side surface close to the image plane, the thirteenth object side surface is convex, and the thirteenth image side surface is concave. The surface is convex; the fourteenth lens 114 includes a fourteenth object-side surface close to the object plane and a fourteenth image-side surface close to the image plane, the fourteenth object-side surface is convex, and the fourteenth image-side surface is concave; the fifteenth lens 115 includes a fifteenth object-side surface close to the object plane and a fifteenth image-side surface close to the image plane, the fifteenth object-side surface is convex, and the fifteenth image-side surface is concave; the sixteenth lens 116 includes a sixteenth object-side surface close to the object plane and a sixteenth image-side surface close to the image plane, the sixteenth object-side surface is concave, and the sixteenth image-side surface is concave; the seventeenth lens 117 includes a seventeenth object-side surface close to the object plane and a seventeenth image-side surface close to the image plane, the seventeenth object-side surface is convex, and the seventeenth image-side surface is convex.

[0095] Specifically, the object-side surface of the lens can be understood as the surface of the lens close to the object plane, and the image-side surface of the lens can be understood as the surface of the lens close to the image plane.

[0096] The object side surface of the first lens 101 is concave, and the image side surface is convex. It can be understood that the object side surface of the first lens 101 is concave toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the first lens 101 is a lens with a concave-convex structure. In addition, the first lens 101 can be a meniscus-shaped negative lens, so that the light rays of the shadow cone angle in the field of view can be collected to achieve the magnification of the light spot. The object side surface of the second lens 102 is concave, and the image side surface is convex. It can be understood that the object side surface of the second lens 102 is concave toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the second lens 102 is a lens with a concave-convex structure. In addition, the second lens 102 can be a meniscus-shaped negative lens, so that the light spot can be further magnified. The object side surface of the third lens 103 is convex, and the image side surface is convex. It can be understood that the object side surface of the third lens 103 is convex toward the object surface at the near optical axis position, and the image side surface is convex toward the image surface at the near optical axis position, that is, the third lens 103 is a lens with a double convex structure, which is used to fix the magnification and slightly converge the light. The third lens 103 slightly converges the light, and its main purpose is to prevent the light spot from being too large and unable to match the image surface after the light passes through the second lens group. In addition, a third lens 103 with a double convex structure is set after the second lens 102 of the meniscus type. Through the cooperation of the second lens 102 and the third lens 103, the light is quickly smoothed to a near-horizontal state and the size of the light spot is slightly reduced, thereby avoiding the second lens group S2 for light shaping from being too long. In summary, the three lenses in the first lens group S1 are set according to the concave-convex, concave-convex and double convex surface types, which can ensure that the light spot on the object side is enlarged to a suitable size, which can not only meet the shaping requirements of the second lens group S2 for the light beam, but also avoid the problem of being unable to match the image surface due to excessive enlargement.

[0097] The object side surface of the fourth lens 104 is convex, and the image side surface is convex. It can be understood that the object side surface of the fourth lens 104 is convex toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the fourth lens 104 is a lens of a double convex structure. The object side surface of the fifth lens 105 is a concave surface, and the image side surface is a concave surface. It can be understood that the object side surface of the fifth lens 105 is concave toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the fifth lens 105 is a lens of a double concave structure. The double convex setting of the fourth lens 104 combined with the double concave setting of the fifth lens can realize the bonding setting of the fourth lens 104 and the fifth lens 105, which is conducive to smaller chromatic aberration. Further, the aberrations generated by the fourth lens 104 and the fifth lens 105 can basically cancel each other, while making the light smoother. In addition, the Abbe coefficients of the fourth lens 104 and the fifth lens 105 are different, so that chromatic aberration can be further reduced.

[0098] Further, the object side surface of the sixth lens 106 is a convex surface, and the image side surface is a concave surface, which can be understood as the object side surface of the sixth lens 106 is convex toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the sixth lens 106 is a lens with a convex-concave structure. The object side surface of the seventh lens 107 is a convex surface, and the image side surface is a convex surface, which can be understood as the object side surface of the seventh lens 107 is convex toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the seventh lens 107 is a lens with a double convex structure. The object side surface of the eighth lens 108 is a concave surface, and the image side surface is a concave surface, which can be understood as the object side surface of the eighth lens 108 is concave toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the eighth lens 108 is a lens with a double concave structure. The object side surface of the ninth lens 109 is convex, and the image side surface is convex. It can be understood that the object side surface of the ninth lens 109 is convex toward the object surface at the near optical axis position, and the image side surface is convex toward the image surface at the near optical axis position, that is, the ninth lens 109 is a lens with a double convex structure. The convex-concave setting of the sixth lens 106, the double convex setting of the seventh lens 107, the double concave setting of the eighth lens 108, and the double convex setting of the ninth lens 109 are combined to ensure that the sixth lens 106, the seventh lens 107, the eighth lens 108, and the ninth lens 109 are glued to realize a four-cemented lens. On the basis of reducing chromatic aberration, the image quality can be further improved, the reflection loss of light energy can be reduced, thereby improving the image quality and enhancing the clarity of the lens imaging. At the same time, the gap between two adjacent lenses can be reduced to ensure that the optical lens structure is more compact.

[0099] Further, the object side surface of the tenth lens 110 is a convex surface, and the image side surface is a convex surface, which can be understood as the object side surface of the tenth lens 110 is convex toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the tenth lens 110 is a lens with a double convex structure. The object side surface of the eleventh lens 111 is a concave surface, and the image side surface is a concave surface, which can be understood as the object side surface of the eleventh lens 111 is concave toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the eleventh lens 111 is a lens with a double concave structure. The object side surface of the twelfth lens 112 is a convex surface, and the image side surface is a concave surface, which can be understood as the object side surface of the twelfth lens 112 is convex toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the twelfth lens 112 is a lens with a convex-concave structure. The biconvex setting of the tenth lens 110, the biconcave setting of the eleventh lens 111 and the convex-concave setting of the twelfth lens 112 are combined to ensure that the tenth lens 110, the eleventh lens 111 and the twelfth lens 112 are glued to form a triplet lens, which can further improve image quality and reduce reflection loss of light energy on the basis of reducing chromatic aberration, thereby improving image quality and enhancing the clarity of lens imaging.

[0100] In summary, the nine lenses in the second lens group S2 are arranged in a doublet lens formed by double convex and double concave, a quadruplet lens formed by convex-concave, double convex, double concave and double convex, and a triplet lens formed by double convex, double concave and convex-concave. Through multiple groups of cemented lenses, chromatic aberration can be effectively eliminated and imaging quality can be improved.

[0101] The object side surface of the thirteenth lens 113 is convex, and the image side surface is convex, which can be understood as the object side surface of the thirteenth lens 113 is convex toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the thirteenth lens 113 is a lens with a double convex structure. The thirteenth lens 113 receives the light from the second lens group and shrinks the light to a certain angle so that the light spot matches the image plane size. The object side surface of the fourteenth lens 114 is convex, and the image side surface is concave, which can be understood as the object side surface of the fourteenth lens 114 is convex toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the fourteenth lens 114 is a lens with a convex-concave structure, and the fourteenth lens 114 is a meniscus lens. The object side surface of the fifteenth lens 115 is convex, and the image side surface is concave. It can be understood that the object side surface of the fifteenth lens 115 is convex toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the fifteenth lens 115 is a lens with a convex-concave structure, and the fifteenth lens 115 is a meniscus lens. The fourteenth lens 114, combined with the double meniscus lens setting of the fifteenth lens 115, can further reduce the spot size to match the image plane. In addition, the third lens group S3 is provided with two meniscus lenses, so that the light is quickly converged, further shortening the length of the optical lens. The object side surface of the sixteenth lens 116 is concave, and the image side surface is concave. It can be understood that the object side surface of the sixteenth lens 116 is concave toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the sixteenth lens 116 is a lens with a double concave structure. The object side surface of the seventeenth lens 117 is convex, and the image side surface is convex. It can be understood that the object side surface of the seventeenth lens 117 is convex toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the seventeenth lens 117 is a lens with a double convex structure. The double concave setting of the sixteenth lens and the double convex setting of the seventeenth lens can allow light to be incident on the image plane at a reasonable angle to achieve a focusing effect. In summary, the five lenses in the third lens group S3 are arranged in a double convex, convex-concave, convex-concave, double concave and double convex manner to fully shrink the light beam and focus the light beam on the image plane to match the image plane size.

[0102] On the basis of the above embodiment, the radius of curvature of the first object side surface is R11, and the radius of curvature of the first image side surface is R12, wherein 7mm<R11<9mm, 10mm<R12<14mm, and the concave-convex surface type of the first lens 101 combined with the curvature radii of the object side surface and the image side surface can further ensure that the first lens 101 amplifies the light beam. The radius of curvature of the second object side surface is R21, and the radius of curvature of the second image side surface is R22, wherein 24mm<R21<30mm, 14mm<R22<18mm, and the concave-convex surface type of the second lens 102 combined with the curvature radii of the object side surface and the image side surface can ensure that the second lens 102 further amplifies the light beam. The radius of curvature of the third object side surface is R31, and the radius of curvature of the third image side surface is R32, wherein 65mm<R31<75mm, 56mm<R32<66mm, and the biconvex type of the third lens 103 combined with the radius of curvature of the object side surface and the image side surface can further ensure that the third lens 103 has a fixed magnification and slightly converges the light. The radius of curvature of the fourth object side surface is R41, and the radius of curvature of the fourth image side surface is R42, wherein 26mm<R41<30mm, 20mm<R42<30mm. The radius of curvature of the fifth object side surface is R51, and the radius of curvature of the fifth image side surface is R52, wherein 20mm<R51<30mm, 22mm<R52<28mm. The radius of curvature of the sixth object side surface is R61, and the radius of curvature of the sixth image side surface is R62, wherein 50mm<R61<60mm, 17mm<R62<22mm. The curvature radius of the seventh object side surface is R71, and the curvature radius of the seventh image side surface is R72, wherein 17mm<R71<22mm, and 13mm<R72<23mm. The curvature radius of the eighth object side surface is R81, and the curvature radius of the eighth image side surface is R82, wherein 13mm<R81<23mm, and 19mm<R82<28mm. The curvature radius of the ninth object side surface is R91, and the curvature radius of the ninth image side surface is R92, wherein 19mm<R91<28mm, and 28mm<R92<34mm. The curvature radius of the tenth object side surface is R101, and the curvature radius of the tenth image side surface is R102, wherein 19mm<R101<23mm, and 75mm<R102<85mm. The radius of curvature of the eleventh object side surface is R111, and the radius of curvature of the eleventh image side surface is R112, wherein 75 mm < R111 < 85 mm, and 13 mm < R112 < 18 mm. The radius of curvature of the twelfth object side surface is R121, and the radius of curvature of the twelfth image side surface is R122, wherein 13 mm < R121 < 18 mm, and 54 mm < R122 < 62 mm.The concave and convex surface of each lens in the second lens group S2, combined with the curvature radius of the object side and the image side, can further achieve the shaping effect of the light beam, so that the non-parallel light in different directions at the same point is converted into parallel light, so as to achieve light beam focusing through the third lens group S3 later. The curvature radius of the thirteenth object side is R131, and the curvature radius of the thirteenth image side is R132, wherein 51mm<R131<61mm, 40mm<R132<50mm. The curvature radius of the fourteenth object side is R141, and the curvature radius of the fourteenth image side is R142, wherein 17mm<R141<21mm, 11mm<R142<15mm. The curvature radius of the fifteenth object side is R151, and the curvature radius of the fifteenth image side is R152, wherein 13mm<R151<17mm, 12mm<R152<14mm. The radius of curvature of the sixteenth object side surface is R161, and the radius of curvature of the sixteenth image side surface is R162, wherein 12mm<R161<14mm, 22mm<R162<32mm. The radius of curvature of the seventeenth object side surface is R171, and the radius of curvature of the seventeenth image side surface is R172, wherein 30mm<R171<36mm, 120mm<R172<135mm. The concave-convex surface type of each lens in the third lens group S3 combined with the radius of curvature of its object side surface and image side surface can further shrink the light beam, so that the light beam finally focused on the image plane can match the size of the image plane, ensuring complete imaging on the image plane.

[0103] On the basis of the above embodiment, the refractive index of the first lens 101 is n1, where 1.85<n1<1.95. The concave-convex surface type of the first lens 101 combined with the curvature radius of its object side and image side and the refractive index of the first lens 101 can further ensure the light beam magnification effect of the first lens 101. The refractive index of the second lens 102 is n2, where 1.8<n2<1.95. Reasonable setting of the refractive index of the second lens 102 can ensure that the second lens 102 can smoothly adjust the light emitted from the first lens 101 on the basis of magnifying the light beam, slow down the magnification rate, and avoid distortion. The refractive index of the third lens 103 is n3, where 1.75<n3<1.8. Reasonable setting of the biconvex surface type, the curvature radius of the object side and the image side and the refractive index of the third lens 103 can ensure that the third lens 103 micro-convexes the light emitted from the second lens 102, and prevent the light spot from being too large after the light passes through the second lens group S3 and cannot match the image surface.

[0104] Further, the refractive index of the fourth lens 104 is n4, wherein 1.55<n4<1.65; the refractive index of the fifth lens 105 is n5, wherein 1.51<n5<1.65; the refractive index of the sixth lens 106 is n6, wherein 1.8<n6<1.9; the refractive index of the seventh lens 107 is n7, wherein 1.6<n7<1.65; the refractive index of the eighth lens 108 is n8, wherein 1.8<n8<1.9; the refractive index of the ninth lens 109 is n9, wherein 1.6<n9<1.65; the refractive index of the tenth lens 110 is n10, wherein 1.6<n10<1.65; the refractive index of the eleventh lens 111 is n11, wherein 1.8<n11<1.95; the refractive index of the twelfth lens 112 is n12, wherein 1.6<n12<1.65. Since the third lens group S3 can be regarded as a convex lens as a whole, and only parallel light can converge to the focal plane after passing through the convex lens, and only one convergence point is formed, it is necessary to make the light parallel before entering the third lens group S3, so that light from different directions at the same point is incident to the third lens group S3 in the form of parallel light. Therefore, by reasonably setting the curvature radius and refractive index of each lens in the second lens group S2 to cooperate with each other, non-parallel light from different directions at the same point can be converted into parallel light, so as to ensure that the third lens group S3 can realize the focusing of the light beam on the focal plane based on parallel light.

[0105] Furthermore, the refractive index of the thirteenth lens 113 is n13, where 1.8<n13<1.95; the refractive index of the fourteenth lens 114 is n14, where 1.6<n14<1.7; the refractive index of the fifteenth lens 115 is n15, where 1.7<n15<1.8; the refractive index of the sixteenth lens 116 is n16, where 1.4<n16<1.5; the refractive index of the seventeenth lens 117 is n17, where 1.85<n17<2. By reasonably setting the refractive index of each lens in the third lens group S3, it is ensured that the third lens group S3 can achieve the effect of shrinking and focusing the light beam, and ensure that the light spot can match the image plane. In addition, the curvature radius and refractive index of the two meniscus lenses, the fourteenth lens 114 and the fifteenth lens 115, can be combined to further improve the focusing effect of the third lens group S3.

[0106] Furthermore, the refractive index of the sixteenth lens 116 is significantly different from the refractive indexes of the first lens 101 , the second lens 102 , the third lens 103 , the sixth lens 106 , the eighth lens 108 , the eleventh lens 111 , the thirteenth lens 113 and the seventeenth lens 117 , so that chromatic aberration can be further reduced.

[0107] Based on the above embodiment, the distance between the third image side surface and the fourth object side surface on the optical axis is L1, where 10mm≤L1≤19mm; the distance between the fifth image side surface and the sixth object side surface on the optical axis is L2, where 0.5mm≤L2≤3mm.

[0108] Specifically, the distance between the third image side surface and the fourth object side surface on the optical axis, that is, the distance between the first lens group S1 and the second lens group S2 on the optical axis, can be reduced by reasonably setting the distance L1 between the third image side surface and the fourth object side surface on the optical axis to satisfy 10mm≤L1≤19mm, so as to reduce the height of the doublet lens formed by the fourth lens 104 and the fifth lens 105. Since the smaller the aperture of the entering light, the smaller the aberration, setting L1 within a reasonable range can reduce the aberration. In addition, the appropriate light aperture is conducive to the change of the angle of the light by the lens behind the optical path, so as to meet the final imaging requirements. Further, 10mm≤L1≤19mm, L1 can specifically be 10mm, 11mm, 11.7mm, 12.5mm, 13.6mm, 15mm, 16.7mm, 17.9mm and 19mm, and the embodiment of the present invention does not specifically limit the distance between the third image side surface and the fourth object side surface on the optical axis.

[0109] The distance between the fifth image side surface and the sixth object side surface on the optical axis, that is, the distance between the fifth lens 105 and the sixth lens 106 on the optical axis, is that the fifth lens 105 is a double concave lens, which can be understood as a concave lens in the modulation of the light path, and the object side surface of the sixth lens 106 is a convex surface, which can be understood as a convex lens in the modulation of the light path. If the distance between the fifth lens 105 and the sixth lens 106 is too large, interference will occur. Therefore, by reasonably setting the distance L2 between the fifth image side surface and the sixth object side surface on the optical axis to meet 0.5mm≤L2≤3mm, on the one hand, it is possible to avoid interference between the fifth lens 105 and the sixth lens 106, and on the other hand, it is possible to avoid increasing the size of the entire optical lens due to the excessive distance between the fifth image side surface and the sixth object side surface. Specifically, 0.5mm≤L2≤3mm, L2 can be 0.5mm, 0.8mm, 1.1mm, 1.5mm, 2.0mm, 2.3mm, 2.6mm and 3mm. The embodiment of the present invention does not specifically limit the distance between the fifth image side surface and the sixth object side surface on the optical axis.

[0110] On the basis of the above embodiments, the distance between the twelfth image side surface and the thirteenth object side surface on the optical axis is L3, wherein 12mm≤L3≤14mm; the distance between the fourteenth image side surface and the fifteenth object side surface on the optical axis is L4, wherein 0mm<L4≤2mm; the distance between the fifteenth image side surface and the sixteenth object side surface on the optical axis is L5, wherein 4mm≤L5≤6mm; the distance between the sixteenth image side surface and the seventeenth object side surface on the optical axis is L6, wherein 6mm≤L6≤8mm.

[0111] Specifically, the distance between the twelfth image side surface and the thirteenth object side surface on the optical axis, that is, the distance between the second lens group S2 and the third lens group S3 on the optical axis, is reasonably set so that the thirteenth lens 113 can shrink the light transmitted by the second lens group S2 by a certain angle so that the light spot matches the image size. Further, 12mm≤L3≤14mm, L3 can specifically be 12mm, 12.3mm, 12.7mm, 13mm, 13.2mm, 13.4mm, 13.7mm and 14mm. The embodiment of the present invention does not specifically limit the distance between the twelfth image side surface and the thirteenth object side surface on the optical axis.

[0112] The distance between the fourteenth image side surface and the fifteenth object side surface on the optical axis, that is, the distance between the fourteenth lens 114 and the fifteenth lens 115 on the optical axis, combined with the design that the fourteenth lens 114 and the fifteenth lens 115 are both meniscus lenses, reasonably sets the distance between the fourteenth image side surface and the fifteenth object side surface on the optical axis, which can further reduce the spot size to match the image plane. Further, 0mm<L4≤2mm, L4 can specifically be 0.3mm, 0.7mm, 1.0mm, 1.2mm, 1.5mm, 1.8mm and 2mm, and the embodiment of the present invention does not specifically limit the distance between the fourteenth image side surface and the fifteenth object side surface on the optical axis.

[0113] The distance between the fifteenth image side surface and the sixteenth object side surface on the optical axis, that is, the distance between the fifteenth lens 115 and the sixteenth lens 116 on the optical axis, the distance between the fifteenth image side surface and the sixteenth object side surface on the optical axis, combined with the convex-concave meniscus lens design of the fifteenth lens 115, the biconcave lens design of the sixteenth lens 116, the curvature radius design of the fifteenth lens 115 and the sixteenth lens 116, and the refractive index design, can converge the main light and the edge light, reducing the edge aberration. Further, 4mm≤L5≤6mm, L5 can specifically be 4mm, 4.3mm, 4.6mm, 4.9mm, 5.1mm, 5.5mm and 6mm, and the embodiment of the present invention does not specifically limit the distance between the fifteenth image side surface and the sixteenth object side surface on the optical axis.

[0114] The distance between the sixteenth image side surface and the seventeenth object side surface on the optical axis, that is, the distance between the sixteenth lens 116 and the seventeenth lens 117 on the optical axis, and the distance between the sixteenth image side surface and the seventeenth object side surface on the optical axis, combined with the biconvex lens design of the seventeenth lens 117, can allow light to be incident on the image plane at a reasonable angle to achieve a focusing effect. Further, 6mm≤L6≤8mm, L6 can specifically be 6mm, 6.3mm, 6.5mm, 6.9mm, 7.2mm, 7.6mm and 8mm, and the embodiment of the present invention does not specifically limit the distance between the sixteenth image side surface and the seventeenth object side surface on the optical axis.

[0115] In summary, by reasonably setting the distance between the third lens group S3 and the second lens group S2 on the optical axis and the distance between the lenses in the third lens group S3 on the optical axis, the focusing effect of the third lens group S3 on the light beam is fully guaranteed, and good imaging is guaranteed on the image plane in a manner that matches the image plane size.

[0116] On the basis of the above embodiments, the optical focal power of the first lens 101 is negative, the optical focal power of the second lens 102 is positive, the optical focal power of the third lens 103 is positive, the optical focal power of the fourth lens 104 is positive, the optical focal power of the fifth lens 105 is negative, the optical focal power of the sixth lens 106 is negative, the optical focal power of the seventh lens 107 is positive or negative, the optical focal power of the eighth lens 108 is negative, the optical focal power of the ninth lens 109 is positive, the optical focal power of the tenth lens 110 is positive, the optical focal power of the eleventh lens 111 is negative, the optical focal power of the twelfth lens 112 is positive or negative, the optical focal power of the thirteenth lens 113 is positive, the optical focal power of the fourteenth lens 114 is negative or positive, the optical focal power of the fifteenth lens 115 is positive or negative, the optical focal power of the sixteenth lens 116 is negative, and the optical focal power of the seventeenth lens 117 is positive.

[0117] Specifically, the focal length is equal to the difference between the convergence degree of the image plane light beam and the convergence degree of the object plane light beam, which characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal length, the stronger the ability to bend light, and the smaller the absolute value of the focal length, the weaker the ability to bend light. When the focal length is a positive number, the refraction of light is convergent; when the focal length is a negative number, the refraction of light is divergent. In an embodiment of the present invention, the first lens 101 is a negative focal length lens. The first lens 101 is a lens group that first adjusts the incident light in the optical lens. The negative focal length setting can effectively deflect the incident light at a large angle, ensure that more light enters the optical system, and thus effectively increase the field of view of the optical lens. Furthermore, the second lens 102, the third lens 103 and the fourth lens 105 are all positive power lenses, so that the second lens 102, the third lens 103 and the fourth lens 104 can timely correct the large aberrations generated by the first lens 101, especially can play a significant correction effect on the edge aberrations of the optical lens, thereby improving the imaging resolution of the optical system. Furthermore, among the multiple lenses from the fifth lens 105 to the seventeenth lens 117, the power distribution roughly follows the method of alternating positive and negative power settings, and there are both positive power lenses and negative power lenses in the four adjacent lenses, which is conducive to correcting aberrations.

[0118] As a feasible implementation method, the specific parameters in the optical lens are described below.

[0119] Table 1 Optical design values ​​of the optical lens in Example 1

[0120]

[0121] In the above table, the radius of curvature represents the degree of curvature of the lens surface, the center thickness represents the center axial distance from the current surface to the next surface, the refractive index represents the ability of the material between the current surface and the next surface to deflect light, and the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface to the light.

[0122] In this embodiment, the optical power distribution manner of the first lens 101 to the seventeenth lens 117 may be negative-positive-positive-positive-negative-negative-positive-negative-positive-positive-negative-positive-positive-negative-positive-positive-negative-positive-positive-negative-positive.

[0123] Furthermore, in this embodiment, the total length of the optical system can be 123.55 mm.

[0124] Furthermore, Figure 2It is a schematic diagram of the MTF curve of an optical lens provided in Example 1 of the present invention. The MTF curve characterizes the ability of the lens to restore the details of the subject. The horizontal axis is the spatial frequency of the line pairs in the object space that are imaged on the image plane through the optical system, and the unit is cycle / mm. The vertical axis is the modulus of the optical transfer function. In the meridian and sagittal directions corresponding to different fields of view (0.000mm, 0.500mm, 1.000mm, 1.500mm and 2.000mm as shown in the figure), the change trend of the optical transfer function increases with the increase of spatial frequency. The most ideal curve is a straight line that coincides with the diffraction limit of the system, indicating that the geometric aberration of the light at all positions is smaller than the wave phase difference caused by the physical limitations of the system itself, and can be ignored. By Figure 2 It can be seen that the optical transfer functions of the system's various fields of view are all greater than or close to 0.1 when imaged at 230lp / mm, indicating that the optical lens has a high resolution.

[0125] Figure 3 : is a schematic diagram of a distortion curve of an optical lens provided in Example 1 of the present invention, wherein the horizontal coordinate represents the magnitude of the distortion, in units of %; the vertical coordinate represents the normalized image height, in units of %. Figure 3 It can be seen that the maximum distortion of the optical lens provided in this embodiment is controlled within 1.2%, the distortion is well corrected, the imaging distortion is small, and the difference between the image and the actual object is small.

[0126] Figure 4 This is a schematic diagram of the vertical axis chromatic aberration curve of an optical lens provided in Example 1 of the present invention. The vertical direction represents the normalized aperture, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum pupil radius. The main wavelength is 587.6nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (μm). Figure 4 It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a good range, indicating that the vertical chromatic aberration of the optical system is well controlled and can meet the needs of wide spectrum applications.

[0127] In summary, the optical lens provided in Embodiment 1 of the present invention adopts an arrangement of three lens groups with a total of seventeen lenses. By reasonably setting the number of lenses in each lens group, the bonding condition, the concave-convex surface condition, the curvature radius parameter, the refractive index parameter, the lens spacing parameter and the optical power (focal length) parameter, etc., clear imaging within the wavelength range of 550 to 850 nm is achieved, and the imaging chromatic aberration is small, the image quality is good and the total optical length range of the lens is short.

[0128] Embodiment 2

[0129] Figure 5 is a schematic diagram of the structure of an optical lens provided in the second embodiment of the present invention, such as Figure 5As shown, the optical lens provided in the first embodiment of the present invention comprises a first lens group S1, a second lens group S2 and a third lens group S3 which are arranged in sequence from the object plane to the image plane along the optical axis; the first lens group S1 comprises a first lens 101, a second lens 102 and a third lens 103; the second lens group comprises at least one group of cemented lenses, and comprises a fourth lens 104, a fifth lens 105, a sixth lens 106, a seventh lens 107, an eighth lens 108, a ninth lens 109, a tenth lens 110, an eleventh lens 111 and a twelfth lens 112; the third lens group S3 comprises a thirteenth lens 113, a fourteenth lens 114, a fifteenth lens 115, a sixteenth lens 116 and a seventeenth lens 117; the first lens group S1 is used to enlarge the light beam size of the object plane, the second lens group S2 is used to shape the light beam, and the third lens group S3 is used to focus the light beam.

[0130] The arrangement of the above-mentioned lens is the same as that of the first embodiment, and will not be described in detail here. Figure 5 and Figure 1 The difference is that Figure 5 The propagation path of the light is shown as an example.

[0131] As another feasible implementation, specific parameters in the optical lens are described below.

[0132] Table 2 An optical design value of the optical lens in Example 2

[0133]

[0134]

[0135] In the above table, the radius of curvature represents the degree of curvature of the lens surface, the center thickness represents the center axial distance from the current surface to the next surface, the refractive index represents the ability of the material between the current surface and the next surface to deflect light, and the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface to the light.

[0136] In this embodiment, the optical power distribution manner of the first lens 101 to the seventeenth lens 117 may be negative-positive-positive-positive-negative-negative-negative-negative-positive-positive-negative-negative-positive-positive-negative-negative-positive-positive-negative-positive.

[0137] Furthermore, in this embodiment, the total length of the optical system can be 147.7 mm.

[0138] Furthermore, Figure 6It is a schematic diagram of the MTF curve of an optical lens provided in Example 2 of the present invention. The MTF curve characterizes the ability of the lens to restore the details of the subject. The horizontal axis is the spatial frequency of the line pairs in the object space that are imaged on the image plane through the optical system, and the unit is cycle / mm. The vertical axis is the modulus of the optical transfer function. In the meridian and sagittal directions corresponding to different fields of view (0.000mm, 1.000mm, 2.000mm, 3.000mm and 4.000mm as shown in the figure), the change trend of the optical transfer function increases with the increase of spatial frequency. The most ideal curve is a straight line that coincides with the diffraction limit of the system, indicating that the geometric aberration of the light at all positions is smaller than the wave phase difference caused by the physical limitations of the system itself, and can be ignored. By Figure 6 It can be seen that the optical transfer functions of the system's various fields of view are all greater than or close to 0.1 when imaged at 230lp / mm, indicating that the optical lens has a high resolution.

[0139] Figure 7 : is a schematic diagram of a distortion curve of an optical lens provided in the second embodiment of the present invention, wherein the horizontal coordinate represents the magnitude of the distortion, in units of %; the vertical coordinate represents the normalized image height, in units of %. Figure 7 It can be seen that the maximum distortion of the optical lens provided in this embodiment is controlled within 0.05%, the distortion is well corrected, the imaging distortion is small, and the difference between the image and the actual object is small.

[0140] Figure 8 This is a schematic diagram of the vertical axis chromatic aberration curve of an optical lens provided in Example 2 of the present invention. The vertical direction represents the normalized aperture, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum pupil radius. The main wavelength is 587.6nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (μm). Figure 8 It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a good range, indicating that the vertical chromatic aberration of the optical system is well controlled and can meet the needs of wide spectrum applications.

[0141] In summary, the optical lens provided in the second embodiment of the present invention adopts an arrangement of three lens groups with a total of seventeen lenses. By reasonably setting the number of lenses in each lens group, the bonding condition, the concave and convex surface condition, the curvature radius parameter, the refractive index parameter, the lens spacing parameter and the optical power (focal length) parameter, etc., clear imaging within the wavelength range of 550 to 850 nm is achieved, and the imaging chromatic aberration is small, the image quality is good, and the total optical length range of the lens is short.

[0142] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical lens, characterized in that: It includes a first lens group, a second lens group and a third lens group which are arranged in sequence from the object plane to the image plane along the optical axis; The first lens group includes a first lens, a second lens and a third lens; the second lens group includes at least one group of cemented lenses, and includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens; the third lens group includes a thirteenth lens, a fourteenth lens, a fifteenth lens, a sixteenth lens and a seventeenth lens; The first lens group is used to enlarge the light beam size of the object plane, the second lens group is used to shape the light beam, and the third lens group is used to focus the light beam.

2. The optical lens according to claim 1, characterized in that: The fourth lens and the fifth lens are cemented together, the sixth lens, the seventh lens, the eighth lens and the ninth lens are cemented together, and the tenth lens, the eleventh lens and the twelfth lens are cemented together.

3. The optical lens according to claim 1, characterized in that: The first lens comprises a first object-side surface close to the object plane and a first image-side surface close to the image plane, the first object-side surface is a concave surface, and the first image-side surface is a convex surface; The second lens comprises a second object-side surface close to the object plane and a second image-side surface close to the image plane, the second object-side surface is a concave surface, and the second image-side surface is a convex surface; The third lens comprises a third object-side surface close to the object plane and a third image-side surface close to the image plane, the third object-side surface is a convex surface, and the third image-side surface is a convex surface; The fourth lens comprises a fourth object-side surface close to the object plane and a fourth image-side surface close to the image plane, the fourth object-side surface is a convex surface, and the fourth image-side surface is a convex surface; The fifth lens comprises a fifth object-side surface close to the object plane and a fifth image-side surface close to the image plane, the fifth object-side surface is a concave surface, and the fifth image-side surface is a concave surface; The sixth lens comprises a sixth object-side surface close to the object plane and a sixth image-side surface close to the image plane, the sixth object-side surface is a convex surface, and the sixth image-side surface is a concave surface; The seventh lens comprises a seventh object-side surface close to the object plane and a seventh image-side surface close to the image plane, the seventh object-side surface is a convex surface, and the seventh image-side surface is a convex surface; The eighth lens comprises an eighth object-side surface close to the object plane and an eighth image-side surface close to the image plane, the eighth object-side surface is a concave surface, and the eighth image-side surface is a concave surface; The ninth lens comprises a ninth object-side surface close to the object plane and a ninth image-side surface close to the image plane, the ninth object-side surface is a convex surface, and the ninth image-side surface is a convex surface; The tenth lens comprises a tenth object-side surface close to the object plane and a tenth image-side surface close to the image plane, the tenth object-side surface is a convex surface, and the tenth image-side surface is a convex surface; The eleventh lens comprises an eleventh object-side surface close to the object plane and an eleventh image-side surface close to the image plane, the eleventh object-side surface is a concave surface, and the eleventh image-side surface is a concave surface; The twelfth lens comprises a twelfth object-side surface close to the object plane and a twelfth image-side surface close to the image plane, the twelfth object-side surface is a convex surface, and the twelfth image-side surface is a concave surface; The thirteenth lens comprises a thirteenth object-side surface close to the object plane and a thirteenth image-side surface close to the image plane, the thirteenth object-side surface is a convex surface, and the thirteenth image-side surface is a convex surface; The fourteenth lens comprises a fourteenth object-side surface close to the object plane and a fourteenth image-side surface close to the image plane, the fourteenth object-side surface is a convex surface, and the fourteenth image-side surface is a concave surface; The fifteenth lens comprises a fifteenth object-side surface close to the object plane and a fifteenth image-side surface close to the image plane, the fifteenth object-side surface is a convex surface, and the fifteenth image-side surface is a concave surface; The sixteenth lens comprises a sixteenth object-side surface close to the object plane and a sixteenth image-side surface close to the image plane, the sixteenth object-side surface is a concave surface, and the sixteenth image-side surface is a concave surface; The seventeenth lens includes a seventeenth object-side surface close to the object plane and a seventeenth image-side surface close to the image plane. The seventeenth object-side surface is a convex surface, and the seventeenth image-side surface is a convex surface.

4. The optical lens according to claim 3, characterized in that: The curvature radius of the first object-side surface is R11, and the curvature radius of the first image-side surface is R12, wherein 7 mm < R11 < 9 mm, and 10 mm < R12 < 14 mm; The curvature radius of the second object-side surface is R21, and the curvature radius of the second image-side surface is R22, wherein 24 mm < R21 < 30 mm, and 14 mm < R22 < 18 mm; The curvature radius of the third object-side surface is R31, and the curvature radius of the third image-side surface is R32, wherein 65 mm < R31 < 75 mm, and 56 mm < R32 < 66 mm; The curvature radius of the fourth object-side surface is R41, and the curvature radius of the fourth image-side surface is R42, wherein 26 mm < R41 < 30 mm, and 20 mm < R42 < 30 mm; The curvature radius of the fifth object-side surface is R51, and the curvature radius of the fifth image-side surface is R52, wherein 20 mm < R51 < 30 mm, and 22 mm < R52 < 28 mm; The curvature radius of the sixth object-side surface is R61, and the curvature radius of the sixth image-side surface is R62, wherein 50 mm < R61 < 60 mm, and 17 mm < R62 < 22 mm; The curvature radius of the seventh object-side surface is R71, and the curvature radius of the seventh image-side surface is R72, wherein 17 mm < R71 < 22 mm, and 13 mm < R72 < 23 mm; The curvature radius of the eighth object-side surface is R81, and the curvature radius of the eighth image-side surface is R82, wherein 13 mm < R81 < 23 mm, and 19 mm < R82 < 28 mm; The curvature radius of the ninth object-side surface is R91, and the curvature radius of the ninth image-side surface is R92, wherein 19 mm < R91 < 28 mm, and 28 mm < R92 < 34 mm; The curvature radius of the tenth object-side surface is R101, and the curvature radius of the tenth image-side surface is R102, wherein 19 mm < R101 < 23 mm, and 75 mm < R102 < 85 mm; The curvature radius of the eleventh object-side surface is R111, and the curvature radius of the eleventh image-side surface is R112, wherein 75 mm < R111 < 85 mm, and 13 mm < R112 < 18 mm; The curvature radius of the twelfth object side surface is R121, and the curvature radius of the twelfth image side surface is R122, wherein 13 mm < R121 < 18 mm, and 54 mm < R122 < 62 mm; The curvature radius of the thirteenth object side surface is R131, and the curvature radius of the thirteenth image side surface is R132, wherein 51 mm<R131<61 mm, and 40 mm<R132<50 mm; The curvature radius of the fourteenth object side surface is R141, and the curvature radius of the fourteenth image side surface is R142, wherein 17 mm < R141 < 21 mm, and 11 mm < R142 < 15 mm; The curvature radius of the fifteenth object side surface is R151, and the curvature radius of the fifteenth image side surface is R152, wherein 13 mm < R151 < 17 mm, and 12 mm < R152 < 14 mm; The curvature radius of the sixteenth object-side surface is R161, and the curvature radius of the sixteenth image-side surface is R162, wherein 12 mm < R161 < 14 mm, and 22 mm < R162 < 32 mm; The curvature radius of the seventeenth object side surface is R171, and the curvature radius of the seventeenth image side surface is R172, wherein 30 mm<R171<36 mm, and 120 mm<R172<135 mm.

5. The optical lens according to claim 3, characterized in that: The distance between the third image-side surface and the fourth object-side surface on the optical axis is L1, wherein 10 mm ≤ L1 ≤ 19 mm; And / or, a distance between the fifth image-side surface and the sixth object-side surface on the optical axis is L2, wherein 0.5 mm ≤ L2 ≤ 3 mm.

6. The optical lens according to claim 3, characterized in that: The distance between the twelfth image-side surface and the thirteenth object-side surface on the optical axis is L3, wherein 12 mm ≤ L3 ≤ 14 mm; The distance between the fourteenth image-side surface and the fifteenth object-side surface on the optical axis is L4, where 0 mm < L4 ≤ 2 mm; The distance between the fifteenth image-side surface and the sixteenth object-side surface on the optical axis is L5, where 4 mm ≤ L5 ≤ 6 mm; A distance between the sixteenth image-side surface and the seventeenth object-side surface on the optical axis is L6, wherein 6 mm ≤ L6 ≤ 8 mm.

7. The optical lens according to claim 1, characterized in that: The refractive index of the first lens is n1, wherein 1.85<n1<1.95; The refractive index of the second lens is n2, wherein 1.8<n2<1.95; The refractive index of the third lens is n3, wherein 1.75<n3<1.8; The refractive index of the fourth lens is n4, wherein 1.55<n4<1.65; The refractive index of the fifth lens is n5, wherein 1.51<n5<1.65; The refractive index of the sixth lens is n6, wherein 1.8<n6<1.9; The refractive index of the seventh lens is n7, wherein 1.6<n7<1.65; The refractive index of the eighth lens is n8, wherein 1.8<n8<1.9; The refractive index of the ninth lens is n9, wherein 1.6<n9<1.65; The refractive index of the tenth lens is n10, wherein 1.6<n10<1.65; The refractive index of the eleventh lens is n11, wherein 1.8<n11<1.95; The refractive index of the twelfth lens is n12, wherein 1.6<n12<1.65; The refractive index of the thirteenth lens is n13, wherein 1.8<n13<1.95; The refractive index of the fourteenth lens is n14, wherein 1.6<n14<1.7; The refractive index of the fifteenth lens is n15, wherein 1.7<n15<1.8; The refractive index of the sixteenth lens is n16, wherein 1.4<n16<1.5; The refractive index of the seventeenth lens is n17, wherein 1.85<n17<2.

8. The optical lens according to claim 1, characterized in that: The optical focal power of the first lens is negative, the optical focal power of the second lens is positive, the optical focal power of the third lens is positive, the optical focal power of the fourth lens is positive, the optical focal power of the fifth lens is negative, the optical focal power of the sixth lens is negative, the optical focal power of the seventh lens is positive or negative, the optical focal power of the eighth lens is negative, the optical focal power of the ninth lens is positive, the optical focal power of the tenth lens is positive, the optical focal power of the eleventh lens is negative, the optical focal power of the twelfth lens is positive or negative, the optical focal power of the thirteenth lens is positive, the optical focal power of the fourteenth lens is negative or positive, the optical focal power of the fifteenth lens is positive or negative, the optical focal power of the sixteenth lens is negative, and the optical focal power of the seventeenth lens is positive.

9. The optical lens according to claim 1, characterized in that: The optical system further includes a stop located in an optical path between the ninth lens and the tenth lens.

10. The optical lens according to claim 1, characterized in that: The total optical length of the optical lens is TTL, wherein TTL is less than 150 mm.

Images