An industrial lens

Abstract

The invention discloses an industrial lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a protective glass, which are arranged in sequence from an object plane to an image plane along an optical axis; the combined focal power of the first lens and the second lens is Φ1_2, the combined focal power of the third lens to the seventh lens is Φ3_7, the focal power of the eighth lens is Φ8, the focal power of the ninth lens is Φ9, the combined focal power of the tenth lens to the twelfth lens is Φ10_12, and the focal power of the industrial lens is Φ; and the conditions satisfy: -0.981<Φ1_2 / Φ<-0.782, 0.886<Φ3_7 / Φ<1.144; -0.694<Φ8 / Φ<0.694, -2.047<Φ9 / Φ<0.986; and 0.554<Φ10_12 / Φ<1.620. Using 12 lenses, by reasonably setting the ratio range of the focal length of each lens to the focal length of the lens, it can support a resolution of 25MP, a target surface of 1.2″, and |optical distortion| ≤ 0.5%, meeting the application requirements of industrial lenses.

Description

Technical Field

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

[0002] With the rise of modern industry, optical lenses are used more and more widely, especially in the field of large field of view detection, such as large-size measurement, PCB (Printed Circuit Board, PCB) board defect detection, floor tile surface texture and color detection, etc. However, short-focal-length optical lenses with large field of view are very scarce in the market today. As the requirements for detection accuracy in large field of view detection in modern industry gradually increase, the industry's performance requirements for optical lenses in terms of field of view, resolution, optical distortion, etc. are becoming more and more stringent.

[0003] The existing industrial lens targets are generally small, usually less than 1". At the same time, camera chips are also gradually becoming larger, and 1.2" imaging chips have gradually become one of the mainstream chips. However, optical lenses for 1.2" imaging chips are currently very scarce, especially high-resolution, large-target wide-angle optical lenses. The existing lenses are also unsatisfactory in terms of distortion, resolution and lens size.

[0004] Therefore, industrial lenses that meet the requirements of high resolution, large target area, and low optical distortion have become an urgent need for applications in this field. Summary of the invention

[0005] The present invention provides an industrial lens, which adopts 12 lenses and can support a resolution of 25MP, a target surface of 1.2″, and an optical distortion of ≤0.5% by reasonably setting the ratio range of the focal power of each lens to the focal power of the lens, thereby meeting the application requirements of the industrial lens.

[0006] An embodiment of the present invention provides an industrial lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a protective glass arranged in sequence from an object plane to an image plane along an optical axis; an aperture is located in the optical path between the seventh lens and the eighth lens;

[0007] The combined focal power of the first lens and the second lens is Φ1_2, the combined focal power of the third lens to the seventh lens is Φ3_7, the focal power of the eighth lens is Φ8, the focal power of the ninth lens is Φ9, the combined focal power of the tenth lens to the twelfth lens is Φ10_12, and the focal power of the industrial lens is Φ;

[0008] Among them, -0.981<Φ1_2 / Φ<-0.782, 0.886<Φ3_7 / Φ<1.144;

[0009] -0.694<Φ8 / Φ<0.694, -2.047<Φ9 / Φ<0.986; 0.554<Φ10_12 / Φ<1.620.

[0010] Optionally, the aperture corresponding to the maximum image height of the image side surface of the first lens is D1S2, the radius of curvature of the image side surface of the first lens at the optical axis is R1S2, the aperture corresponding to the maximum image height of the image side surface of the fifth lens is D5S2, the radius of curvature of the image side surface of the fifth lens at the optical axis is R5S2, the aperture corresponding to the maximum image height of the image side surface of the sixth lens is D6S2, the radius of curvature of the image side surface of the sixth lens at the optical axis is R6S2, the aperture corresponding to the maximum image height of the image side surface of the seventh lens is D7S2, and the radius of curvature of the image side surface of the seventh lens at the optical axis is R7S2; wherein, 1.159≤D1S2 / R1S2≤1.505; 0.142≤D5S2 / R5S2≤0.868;

[0011] 0.113≤D6S2 / R6S2≤1.034; 0.287≤D7S2 / R7S2≤1.158.

[0012] Optionally, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens form a focusing group, and the tenth lens, the eleventh lens and the twelfth lens form a fixed group.

[0013] Optionally, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens form a focusing group, and the twelfth lens is a fixed group.

[0014] Optionally, the focal length of the focusing group is EFL1, and the focal length of the fixed group is EFL2, wherein 0.787≤EFL1 / EFL2≤1.051.

[0015] Optionally, the moving distance of the focusing group is ZOL, the distance from the center of the optical axis of the image side surface of the twelfth lens industrial lens to the image plane is BFL; 0.423≤ZOL / BFL≤0.569.

[0016] Optionally, the refractive index of the first lens is n1, the refractive index of the second lens is n2, the refractive index of the third lens is n3, the refractive index of the fourth lens is n4, the refractive index of the fifth lens is n5, the refractive index of the sixth lens is n6, and the refractive index of the seventh lens is n7; the refractive index of the eighth lens is n8, the refractive index of the ninth lens is n9, the refractive index of the tenth lens is n10, the refractive index of the eleventh lens is n11, and the refractive index of the twelfth lens is n12;

[0017] Among them, 1.437≤n1≤2.072; 1.347≤n2≤1.869, 1.521≤n3≤2.163;

[0018] 1.434≤n4≤2.205; 1.434≤n5≤2.075; 1.434≤n6≤1.845;

[0019] 1.664≤n7≤2.139; 1.346≤n8≤2.134; 1.453≤n9≤2.094;

[0020] 1.346≤n10≤1.991; 1.625≤n11≤2.079; 1.694≤n12≤2.210.

[0021] Optionally, the Abbe number of the first lens is v1, the Abbe number of the second lens is v2, the Abbe number of the third lens is v3, the Abbe number of the fourth lens is v4, the Abbe number of the fifth lens is v5, the Abbe number of the sixth lens is v6, and the Abbe number of the seventh lens is v7; the Abbe number of the eighth lens is v8, the Abbe number of the ninth lens is v9, the Abbe number of the tenth lens is v10, the Abbe number of the eleventh lens is v11, and the Abbe number of the twelfth lens is v12;

[0022] Among them, 37.386≤v1≤99.000; 28.636≤v2≤90.714, 27.781≤v3≤62.528;

[0023] 25.494≤v4≤75.919; 36.518≤v5≤88.887; 53.198≤v6≤84.304;

[0024] 14.956≤v7≤33.076; 22.846≤v8≤83.329; 28.318≤v9≤57.502;

[0025] 20.132≤v10≤99.000; 22.998≤v11≤93.511; 26.562≤v12≤39.772.

[0026] Optionally, the first lens to the twelfth lens are all glass spherical lenses.

[0027] Optionally, a surface of the lens close to the object plane is an object side surface, and a surface of the lens close to the image plane is an image side surface;

[0028] The object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface;

[0029] The object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface;

[0030] The object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface;

[0031] The object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface;

[0032] The object side surface of the fifth lens is convex, and the image side surface of the first lens is concave;

[0033] The object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface;

[0034] The object side surface of the seventh lens is convex, and the image side surface of the sixth lens is concave;

[0035] The object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens is a convex surface;

[0036] The object side surface of the ninth lens is a concave surface, and the image side surface of the ninth lens is a convex surface;

[0037] The object side surface of the tenth lens is a concave surface, and the image side surface of the tenth lens is a concave surface;

[0038] The object side surface of the eleventh lens is a concave surface, and the image side surface of the eleventh lens is a convex surface;

[0039] The object side surface of the twelfth lens is a convex surface, and the image side surface of the twelfth lens is a convex surface.

[0040] The industrial lens provided by the embodiment of the present invention comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a protective glass arranged in sequence from an object plane to an image plane along an optical axis; the combined focal power of the first lens and the second lens is Φ1_2, the combined focal power of the third lens to the seventh lens is Φ3_7, the focal power of the eighth lens is Φ8, the focal power of the ninth lens is Φ9, the combined focal power of the tenth lens to the twelfth lens is Φ10_12, and the focal power of the industrial lens is Φ; -0.981<Φ1_2 / Φ<-0.782, 0.886<Φ3_7 / Φ<1.144; -0.694<Φ8 / Φ<0.694, -2.047<Φ9 / Φ<0.986; 0.554<Φ10_12 / Φ<1.620 are satisfied. Using 12 lenses, by reasonably setting the ratio range of the focal length of each lens to the focal length of the lens, it can support a resolution of 25MP, a target surface of 1.2″, and |optical distortion| ≤ 0.5%, meeting the application requirements of industrial lenses. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of the structure of an industrial lens provided in Example 1:

[0042] Figure 2 A ray fan diagram of an industrial lens provided in Example 1:

[0043] Figure 3 A field curvature distortion curve diagram of an industrial lens provided in Example 1:

[0044] Figure 4 A schematic diagram of the structure of an industrial lens provided for Example 2:

[0045] Figure 5 A ray fan diagram of an industrial lens provided in Example 2:

[0046] Figure 6 A field curvature distortion curve diagram of an industrial lens provided in Example 2:

[0047] Figure 7 A schematic diagram of the structure of an industrial lens provided for Example 3:

[0048] Figure 8 A ray fan diagram of an industrial lens provided in Example 3:

[0049] Fig. 9 This is a field curvature distortion curve diagram of an industrial lens provided in Example 3. DETAILED DESCRIPTION

[0050] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0051] Embodiment 1

[0052] Figure 1 This is a schematic diagram of the structure of an industrial lens provided in Example 1. Figure 1 As shown, an industrial lens provided by an embodiment of the present invention includes a first lens 101, a second lens 102, a third lens 103, 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, a twelfth lens 112 and a protective glass 113 arranged in sequence from an object plane to an image plane along an optical axis; an aperture 114 is located in the optical path between the seventh lens 107 and the eighth lens 108; the combined optical focal length of the first lens 101 and the second lens 102 is Φ1_2, the combined optical focal length of the third lens 103 to the seventh lens 107 is Φ3_7, the optical focal length of the eighth lens 108 is Φ8, the optical focal length of the ninth lens 109 is Φ9, the combined optical focal length of the tenth lens 110 to the twelfth lens 112 is Φ10_12, and the optical focal length of the industrial lens is Φ. Among them, -0.981<Φ1_2 / Φ<-0.782, 0.886<Φ3_7 / Φ<1.144; -0.694<Φ8 / Φ<0.694, -2.047<Φ9 / Φ<0.986; 0.554<Φ10_12 / Φ<1.620.

[0053] Specifically, the surface of the lens adjacent to the object plane is the object side surface, and the surface of the lens adjacent to the image plane is the image side surface. The optical focal length is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam. Its value is the reciprocal of the focal length, and it characterizes the ability of the optical system to deflect light. The larger the absolute value of the optical focal length, the stronger the ability to bend light, and the smaller the absolute value of the optical focal length, the weaker the ability to bend light. When the optical focal length is a positive number, the refraction of light is convergent; when the optical focal length is a negative number, the refraction of light is divergent. The optical focal length can be used to characterize a refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a certain lens, and can also be used to characterize a system formed by multiple lenses (i.e., a lens group).

[0054] Combination Figure 1As shown, in this embodiment, 12 lenses are used, including a first lens 101, a second lens 102, a third lens 103, 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, a twelfth lens 112 and a protective glass 113 which are arranged in sequence from the object plane to the image plane along the optical axis. In this embodiment, an aperture 114 is arranged in the optical path between the seventh lens 107 and the eighth lens 108 to adjust the propagation direction of the light beam and the incident angle of the light, which is beneficial to improving the imaging quality.

[0055] The optical power of each lens is further set, such as setting the ratio of the combined optical power Φ1_2 of the first lens 101 and the second lens 102 to the optical power Φ of the industrial lens to Φ, which satisfies -0.981<Φ1_2 / Φ<-0.782; setting the ratio of the combined optical power Φ3_7 of the third lens 103 to the seventh lens 107 to the optical power Φ of the industrial lens to Φ to Φ3_7 / Φ satisfies 0.886<Φ3_7 / Φ<1.144. Since the off-axis light of the industrial lens is at a high height, it has a greater impact on the aberration. In the embodiment of the present application, by constraining the ratio of the optical power of the first lens 101 to the seventh lens 107 at the front end of the aperture 114 to the industrial lens, the ratio constrains the optical power to be within the above range, which can converge the off-axis light and reduce the aberration caused by it.

[0056] Since the system distortion is the sum of the distortions generated by all lenses, the present application further constrains the focal power of each lens at the rear end of the aperture 114 to balance the distortions generated by all lenses, such as setting the focal power Φ8 of the eighth lens 108 to the focal power Φ of the industrial lens to be a ratio of Φ8 / Φ, which satisfies -0.694<Φ8 / Φ<0.694; the focal power of the ninth lens 109 is Φ9 and the focal power of the industrial lens is Φ9 / Φ, which satisfies -2.047<Φ9 / Φ<0.9 86; Setting the ratio of the combined optical power Φ10_12 of the tenth lens 110 to the twelfth lens 112 to the optical power Φ of the industrial lens Φ10_12 / Φ to satisfy 0.554<Φ10_12 / Φ<1.620 can balance the lens distortion and make the |optical distortion| of the lens ≤0.5%; and setting the optical power of the first lens 101 to the twelfth lens 112 within this range can balance the aberration, thereby meeting the application requirements of a large target surface of 1.2″.

[0057] In summary, the industrial lens provided in the embodiment of the present application adopts the form of a combination of 12 lenses. By reasonably setting the ratio range of the focal length of each lens to the focal length of the lens, it can support a resolution of 25MP, a target surface of 1.2″, and |optical distortion|≤0.5%, meeting the application requirements of industrial lenses.

[0058] Based on the above embodiments, continue to refer to Figure 1 As shown, the surface of the lens close to the object plane is the object side surface, and the surface of the lens close to the image plane is the image side surface. The object side surface of the first lens 101 is convex, and the image side surface of the first lens 101 is concave; the object side surface of the second lens 102 is concave, and the image side surface of the second lens 102 is concave; the object side surface of the third lens 103 is concave, and the image side surface of the third lens 103 is convex; the object side surface of the fourth lens 104 is convex, and the image side surface of the fourth lens 104 is convex; the object side surface of the fifth lens 105 is convex, and the image side surface of the first lens 101 is concave; the object side surface of the sixth lens 106 is convex, and the image side surface of the sixth lens 106 is convex; The object side surface of the seventh lens 107 is convex, and the image side surface of the sixth lens 106 is concave; the object side surface of the eighth lens 108 is concave, and the image side surface of the eighth lens 108 is convex; the object side surface of the ninth lens 109 is concave, and the image side surface of the ninth lens 109 is convex; the object side surface of the tenth lens 110 is concave, and the image side surface of the tenth lens 110 is concave; the object side surface of the eleventh lens 111 is concave, and the image side surface of the eleventh lens 111 is convex; the object side surface of the twelfth lens 112 is convex, and the image side surface of the twelfth lens 112 is convex.

[0059] Specifically, by reasonably setting the surface shapes of the object side and the image side of the first lens 101 to the twelfth lens 112, the light passing through each lens is controlled to ensure that the optical focal length of each lens meets the optical focal length requirements in the above embodiment, while also ensuring that the entire industrial lens structure is compact and the lens integration is improved.

[0060] Based on the above embodiments, Figure 1As shown, considering that the lens of a large target surface has a large aperture, the processability of the lens is a major difficulty. The present application improves the manufacturability of each lens by setting the ratio of the aperture to the radius of curvature of the lens. Specifically, the aperture corresponding to the maximum image height of the image side of the first lens 101 is set to D1S2, the radius of curvature of the image side of the first lens 101 at the optical axis is R1S2, and the ratio D1S2 / R1S2 satisfies 1.159≤D1S2 / R1S2≤1.505; the aperture corresponding to the maximum image height of the image side of the fifth lens 105 is set to D5S2, the radius of curvature of the image side of the fifth lens 105 at the optical axis is R5S2, and the ratio D5S2 / R5S2 satisfies 0.142≤D5S2 / R5S2≤0.8 68; the maximum image height of the image side surface of the sixth lens 106 corresponds to an aperture of D6S2, the radius of curvature of the image side surface of the sixth lens 106 at the optical axis is R6S2, the ratio D6S2 / R6S2 satisfies 0.113≤D6S2 / R6S2≤1.034, the maximum image height of the image side surface of the seventh lens 107 corresponds to an aperture of D7S2, the radius of curvature of the image side surface of the seventh lens 107 at the optical axis is R7S2, the ratio D7S2 / R7S2 satisfies 0.287≤D7S2 / R7S2≤1.158. Wherein, the image side surface refers to the side surface of the lens facing the image plane.

[0061] Based on the above embodiments, Figure 1 As shown, the industrial lens provided in the embodiment of the present application can be focused by moving the lens group. In a feasible implementation manner, the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, the seventh lens 107, the eighth lens 108 and the ninth lens 109 are the focusing group S1, and the tenth lens 110, the eleventh lens 111, and the twelfth lens 112 are the fixed group S2.

[0062] Specifically, by moving the focus interval between the focus group S1 and the fixed group S2, it can be ensured that the focal length of the industrial lens remains unchanged and the image quality deteriorates less during the focusing process. As an example, the focal length of the industrial lens provided in the embodiment of the present application is 16.000±0.005mm.

[0063] Based on the above embodiments, Figure 1 As shown, the focal length of the focus group S1 is EFL1, and the focal length of the fixed group S2 is EFL2, wherein 0.787≤EFL1 / EFL2≤1.051. By limiting the focal length EFL1 of the focus group S1 and the focal length EFL2 of the fixed group S2 to meet the above requirements, the focal lengths of the focus group S1 and the fixed group S2 are reasonably allocated, which is conducive to ensuring the focal length of the lens and the image quality during the focusing process.

[0064] Based on the above embodiments, Figure 1As shown, the moving distance of the focus group S1 along the optical axis L0 is ZOL, and the distance from the optical axis center of the image side of the twelfth lens 112 industrial lens to the image plane M is BFL; 0.423≤ZOL / BFL≤0.569. By limiting the moving distance ZOL of the focus group S1 along the optical axis L0 and the distance BFL from the optical axis center of the image side of the twelfth lens 112 industrial lens to the image plane M to meet the above requirements, it is beneficial to compress the total optical length TTL of the industrial lens and realize the miniaturization of the lens. Among them, the distance from the optical axis center of the object side of the first lens 101 to the image plane is the total optical length TTL of the industrial lens.

[0065] Based on the above embodiments, Figure 1 As shown, the refractive index of the first lens 101 is n1, the refractive index of the second lens 102 is n2, the refractive index of the third lens 103 is n3, the refractive index of the fourth lens 104 is n4, the refractive index of the fifth lens 105 is n5, the refractive index of the sixth lens 106 is n6, and the refractive index of the seventh lens 107 is n7; the refractive index of the eighth lens 108 is n8, the refractive index of the ninth lens 109 is n9, the refractive index of the tenth lens 110 is n10, the refractive index of the eleventh lens 111 is n11, and the refractive index of the twelfth lens 112 is n1 2; among which, 1.437≤n1≤2.072; 1.347≤n2≤1.869, 1.521≤n3≤2.163; 1.434≤n4≤2.205; 1.434≤n5≤2.075; 1.434≤n6≤1.845; .664≤n7≤2.139; .346≤n8≤2.134; 1.453≤n9≤2.094; 1.346≤n10≤1.991; 1.625≤n11≤2.079; 1.694≤n12≤2.210.

[0066] Based on the above embodiments, Figure 1As shown, the Abbe number of the first lens 101 is v1, the Abbe number of the second lens 102 is v2, the Abbe number of the third lens 103 is v3, the Abbe number of the fourth lens 104 is v4, the Abbe number of the fifth lens 105 is v5, the Abbe number of the sixth lens 106 is v6, and the Abbe number of the seventh lens 107 is v7; the Abbe number of the eighth lens 108 is v8, the Abbe number of the ninth lens 109 is v9, the Abbe number of the tenth lens 110 is v10, the Abbe number of the eleventh lens 111 is v11, and the Abbe number of the twelfth lens 112 is v12; wherein, 37.386≤v 1≤99.000;28.636≤v2≤90.714,27.781≤v3≤62.528;25.494≤v4≤75.919;36.518≤v5≤88.887;53.198≤v6≤84.304;14.956≤v7≤33.076;22.846≤v8≤83.329;28.318≤v9≤57.502;20.132≤v10≤99.000;22.998≤v11≤93.511;26.562≤v12≤39.772。

[0067] Among them, the refractive index is the ratio of the propagation speed of light in a vacuum to the propagation speed of light in the medium. It is mainly used to describe the material's ability to refract light. Different materials have different refractive indices. The Abbe number is an index used to represent the dispersion ability of a transparent medium. The more severe the dispersion of the medium, the smaller the Abbe number; conversely, the milder the dispersion of the medium, the larger the Abbe number.

[0068] In this embodiment, by matching the refractive index and Abbe number of the first lens 101 to the twelfth lens 112 in the industrial lens, the balance of the incident angles of the front and rear lens groups can be ensured, the sensitivity of the lens can be reduced, and it is beneficial to achieve a miniaturized design of the industrial lens; at the same time, it is also beneficial to achieve a higher pixel resolution and a larger aperture.

[0069] Based on the above embodiments, Figure 1 As shown, considering that glass lenses have a strong light-reflecting ability, setting the first lens 101 to the twelfth lens 112 to be glass spherical lenses helps to compress the volume of the 12 lenses and also reduce the number of lenses, thereby reducing the total volume of the industrial lens.

[0070] It should be noted that the material of the glass spherical lens is various types of glass known to those skilled in the art, and the embodiment of the present invention will not elaborate on this and will not limit this.

[0071] As an example, Table 1 details the specific optical and physical parameters of each lens in an industrial lens provided in Embodiment 1 of the present invention.

[0072] Table 1 Design values ​​of optical physical parameters of industrial lenses

[0073]

[0074]

[0075] Among them, the surface numbers in Table 1 are numbered according to the surface order of each lens, for example, surface number 1 represents the object side surface of the first lens, surface number 2 represents the image side surface of the first lens, surface number 3 represents the object side surface of the second lens, surface number 4 represents the image side surface of the second lens, and so on; R is the radius of curvature, representing the curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; T is the thickness, representing the central axial distance from the current surface to the next surface, and the units of the radius of curvature and thickness are both millimeters (mm); nd is the refractive index, representing the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air, and the refractive index is 1; vd is the Abbe number, representing the dispersion characteristics of the material between the current surface and the next surface to light; D is the semi-aperture, representing half of the aperture size of the current surface.

[0076] Table 2 shows the values ​​of the focus intervals in Table 1, in millimeters (mm). The focus interval in the first embodiment of the present application refers to the central axial distance from the image side surface of the ninth lens to the object side surface of the tenth lens.

[0077] Table 2 Design values ​​of focus interval

[0078] Object distance Object distance 100mm Object distance 1000mm Focus interval 6.010 1.328

[0079] Combination Figure 1 As shown in Table 1 and Table 2, as an example, when the lens object distance is 100mm, the focus group S1 is moved along the optical axis L0, so that the focus interval between the focus group S1 and the fixed group S2 is 6.010mm; as an example, when the lens object distance is 1000mm, the focus group S1 is moved along the optical axis L0, so that the focus interval between the focus group S1 and the fixed group S2 is 1.328mm. According to the object distance, the lens focus interval is adjusted to ensure that the focal length of the industrial lens remains unchanged. According to Table 1 and Table 2, the focal length of the industrial lens is 15.998mm. The object distance refers to the distance from the center of the optical axis of the object side of the first lens to the object plane.

[0080] Figure 2A ray fan diagram of an industrial lens provided in Example 1. The ray fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis in the ray fan diagram is the beam aperture, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane. The corresponding interval on the vertical axis of the curve is the maximum dispersion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberrations of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. By Figure 2 It can be seen that the industrial lens provided in Example 1 of the present application is well close to the horizontal axis at each wavelength in each field of view, indicating that the vertical axis aberration of each wavelength of the industrial lens is well corrected. At the same time, there is no obvious dispersion of each wavelength from the light with a wavelength of 449nm to the light with a wavelength of 680nm, indicating that the system chromatic aberration is also well corrected, thereby ensuring that the industrial lens can achieve high-resolution imaging requirements.

[0081] Figure 3 This is a field curvature distortion curve diagram of an industrial lens provided in Example 1. Figure 3 As shown, in the left coordinate system, the horizontal coordinate represents the magnitude of field curvature, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, S represents arc loss; Figure 3 It can be seen from the left coordinate system that the field curvature of the industrial lens provided in this embodiment is effectively controlled, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; in the right coordinate system, the horizontal coordinate represents the size of the distortion, in units of %; the vertical coordinate represents the normalized image height, without units, represented by Figure 3 It can be seen from the left coordinate system that the field curvature of the industrial lens provided in the first embodiment from the light with a wavelength of 449nm to the light with a wavelength of 680nm is effectively controlled within (-0.04, +0.09), and is well corrected, with small imaging distortion, meeting the requirement of low distortion.

[0082] In summary, the present invention adopts a combination structure of 12 all-glass lenses, and realizes an industrial lens design that can take into account high resolution, large target surface, and low optical distortion by matching lens materials and reasonably allocating the optical power of each lens element. The resolution can support 25MP, the target surface is 1.2″, and |optical distortion|≤0.5%.

[0083] Embodiment 2

[0084] Figure 4 This is a schematic diagram of the structure of an industrial lens provided in Example 2. Figure 4As shown, an industrial lens provided by an embodiment of the present invention comprises a first lens 201, a second lens 202, a third lens 203, a fourth lens 204, a fifth lens 205, a sixth lens 206, a seventh lens 207, an eighth lens 208, a ninth lens 209, a tenth lens 210, an eleventh lens 211, a twelfth lens 212 and a protective glass 113 arranged in sequence along the optical axis from the object plane to the image plane. The aperture 114 is arranged in the optical path between the seventh lens 107 and the eighth lens 108, and is used to adjust the propagation direction of the light beam and the incident angle of the light, which is conducive to improving the imaging quality.

[0085] As an example, Table 3 details the specific optical and physical parameters of each lens in the industrial lens provided in Embodiment 2 of the present invention.

[0086] Table 3 Design values ​​of optical physical parameters of industrial lenses

[0087]

[0088]

[0089] Among them, the surface numbers in Table 1 are numbered according to the surface order of each lens, for example, surface number 1 represents the object side surface of the first lens, surface number 2 represents the image side surface of the first lens, surface number 3 represents the object side surface of the second lens, surface number 4 represents the image side surface of the second lens, and so on; R is the radius of curvature, representing the curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; T is the thickness, representing the central axial distance from the current surface to the next surface, and the units of the radius of curvature and thickness are both millimeters (mm); nd is the refractive index, representing the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air, and the refractive index is 1; vd is the Abbe number, representing the dispersion characteristics of the material between the current surface and the next surface to light; D is the semi-aperture, representing half of the aperture size of the current surface.

[0090] Based on the above embodiments, Figure 4 As shown, the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, the seventh lens 107, the eighth lens 108, the ninth lens 109, the tenth lens 110 and the eleventh lens 111 are a focusing group S1, and the twelfth lens 112 is a fixed group S2.

[0091] Table 4 shows the values ​​of the focus intervals in Table 3, in millimeters (mm). The focus interval in Example 2 of the present application refers to the central axial distance from the image side surface of the eleventh lens to the object side surface of the twelfth lens, that is, the moving distance of the focus group along the optical axis is ZOL.

[0092] Table 6 Design values ​​of focus interval

[0093] Object distance Object distance 100mm Object distance 1000mm Focus interval 6.636 1.476

[0094] Combination Figure 4 As shown in Table 3 and Table 4, as an example, when the lens object distance is 100mm, the focus group S1 is moved along the optical axis L0, so that the focus interval between the focus group S1 and the fixed group S2 is 6.636mm; as an example, when the lens object distance is 1000mm, the focus group S1 is moved along the optical axis L0, so that the focus interval between the focus group S1 and the fixed group S2 is 1.476mm. According to the object distance, the lens focus interval is adjusted to ensure that the focal length of the industrial lens remains unchanged. According to the parameters in Table 3 and Table 4, the focal length of the industrial lens is 15.996mmmm.

[0095] Figure 5 This is a ray fan diagram of an industrial lens provided in Example 2. Figure 5 It can be seen that the industrial lens provided in Example 2 of the present application is well close to the horizontal axis at each wavelength in each field of view, indicating that the vertical axis aberration of each wavelength of the industrial lens is well corrected. At the same time, there is no obvious dispersion of each wavelength from the light with a wavelength of 449nm to the light with a wavelength of 680nm, indicating that the system chromatic aberration is also well corrected, thereby ensuring that the industrial lens can achieve high-resolution imaging requirements.

[0096] Figure 6 This is a field curvature distortion curve diagram of an industrial lens provided in Example 2. Figure 6 As shown, in the left coordinate system, the horizontal coordinate represents the magnitude of field curvature, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, S represents arc loss; Figure 6 It can be seen from the left coordinate system that the field curvature of the industrial lens provided in this embodiment is effectively controlled, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; in the right coordinate system, the horizontal coordinate represents the size of the distortion, in units of %; the vertical coordinate represents the normalized image height, without units, represented by Figure 6 It can be seen from the left coordinate system that the field curvature of the industrial lens provided in the first embodiment from the light with a wavelength of 449nm to the light with a wavelength of 680nm is effectively controlled within (-0.05, +0.1), and is well corrected, with small imaging distortion, meeting the requirement of low distortion.

[0097] Embodiment 3

[0098] Figure 7 This is a schematic diagram of the structure of an industrial lens provided in Example 3. Figure 7As shown, an industrial lens provided by an embodiment of the present invention comprises a first lens 301, a second lens 302, a third lens 303, a fourth lens 304, a fifth lens 305, a sixth lens 306, a seventh lens 307, an eighth lens 308, a ninth lens 309, a tenth lens 310, an eleventh lens 311, a twelfth lens 312 and a protective glass 313 arranged in sequence along the optical axis from the object plane to the image plane. A stop 314 is provided in the optical path between the seventh lens 307 and the eighth lens 308, and is used to adjust the propagation direction of the light beam and the incident angle of the light, which is conducive to improving the imaging quality.

[0099] As an example, Table 5 details the specific optical and physical parameters of each lens in the industrial lens provided in Embodiment 3 of the present invention.

[0100] Table 5 Design values ​​of optical physical parameters of industrial lenses

[0101]

[0102]

[0103] Among them, the surface numbers in Table 5 are numbered according to the surface order of each lens, for example, surface number 1 represents the object side surface of the first lens, surface number 2 represents the image side surface of the first lens, surface number 3 represents the object side surface of the second lens, surface number 4 represents the image side surface of the second lens, and so on; R is the radius of curvature, representing the curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; T is the thickness, representing the central axial distance from the current surface to the next surface, and the units of the radius of curvature and thickness are both millimeters (mm); nd is the refractive index, representing the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air, and the refractive index is 1; vd is the Abbe number, representing the dispersion characteristics of the material between the current surface and the next surface to light; D is the semi-aperture, representing half of the aperture size of the current surface.

[0104] Based on the above embodiments, Figure 7 As shown, the industrial lens provided in the embodiment of the present application is focused by group movement, and the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, the seventh lens 107, the eighth lens 108 and the ninth lens 109 are set as the focusing group S1, and the tenth lens 110, the eleventh lens 111, and the twelfth lens 112 are set as the fixed group S2.

[0105] Table 6 shows the values ​​of the focus intervals in Table 5, in millimeters (mm). The focus interval in Example 3 of the present application refers to the central axial distance from the image side surface of the ninth lens to the object side surface of the tenth lens, and the moving distance of the focus group along the optical axis is ZOL.

[0106] Table 6 Design values ​​of focusing intervals for industrial lenses

[0107] Object distance Object distance 100mm Object distance 1000mm Focus interval 6.191 1.565

[0108] Combination Figure 7 As shown in Table 5 and Table 6, as an example, when the lens object distance is 100mm, the focus group S1 is moved along the optical axis L0, so that the focus interval between the focus group S1 and the fixed group S2 is 6.191mm; as an example, when the lens object distance is 1000mm, the focus group S1 is moved along the optical axis L0, so that the focus interval between the focus group S1 and the fixed group S2 is 1.565mm. According to the object distance, the lens focus interval is adjusted to ensure that the focal length of the industrial lens remains unchanged. According to the parameters in Table 5 and Table 6, the focal length of the industrial lens is 16.004mm.

[0109] Figure 8 This is a ray fan diagram of an industrial lens provided in Example 3. Figure 8 It can be seen that the industrial lens provided in Example 3 of the present application is well close to the horizontal axis at each wavelength in each field of view, indicating that the vertical axis aberration of each wavelength of the industrial lens is well corrected. At the same time, from the light with a wavelength of 449nm to the light with a wavelength of 680nm, there is no obvious dispersion of each wavelength, indicating that the system chromatic aberration is also well corrected, thereby ensuring that the industrial lens can achieve high-resolution imaging requirements.

[0110] Fig. 9 This is a field curvature distortion curve diagram of an industrial lens provided in Example 3. Fig. 9 As shown, in the left coordinate system, the horizontal coordinate represents the magnitude of field curvature, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, S represents arc loss; Fig. 9 It can be seen from the left coordinate system that the field curvature of the industrial lens provided in this embodiment is effectively controlled, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; in the right coordinate system, the horizontal coordinate represents the size of the distortion, in units of %; the vertical coordinate represents the normalized image height, without units, represented by Fig. 9 It can be seen from the left coordinate system that the field curvature of the industrial lens provided in the first embodiment from the light with a wavelength of 449nm to the light with a wavelength of 680nm is effectively controlled within (-0.05, +0.1), and is well corrected, with small imaging distortion, meeting the requirement of low distortion.

[0111] In order to more clearly illustrate the above embodiments, Table 7 details the specific optical and physical parameters of each lens in the industrial lens provided by Embodiments 1 to 3 of the present invention and other feasible optical and physical parameters.

[0112] Table 7 Design values ​​of optical physical parameters of industrial lenses

[0113] Scope of protection Example 1 Example 2 Example 3 Lower limit Upper limit D1S2 / R1S2 1.324 1.368 1.288 1.159 1.505 D5S2 / R5S2 0.788 0.517 0.157 0.142 0.868 D6S2 / R6S2 0.125 0.940 0.525 0.113 1.034 D7S2 / R7S2 0.861 0.319 1.053 0.287 1.158 Φ1_2 / Φ -0.893 -0.870 -0.870 -0.981 -0.782 Φ3_7 / Φ 1.041 0.984 0.984 0.886 1.144 Φ8 / Φ -0.632 0.632 -0.549 -0.694 0.694 Φ9 / Φ 0.897 -2.247 0.671 -2.047 0.986 Φ10_12 / Φ 0.650 1.473 0.615 0.554 1.620 ZOL / BFL 0.477 0.518 0.469 0.423 0.569 EFL1 / EFL2 0.956 0.874 0.886 0.787 1.051

[0114] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection 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, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An industrial lens, characterized in that: The industrial lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a protective glass arranged in sequence from the object plane to the image plane along the optical axis; the aperture is located in the optical path between the seventh lens and the eighth lens; the number of lenses with optical power in the industrial lens is twelve; The first lens has negative optical power, the second lens has negative optical power, the fourth lens has positive optical power, the fifth lens has positive optical power, the sixth lens has positive optical power, the seventh lens has negative optical power, and the twelfth lens has positive optical power; The combined focal power of the first lens and the second lens is Φ1_2, the combined focal power of the third lens to the seventh lens is Φ3_7, the focal power of the eighth lens is Φ8, the focal power of the ninth lens is Φ9, the combined focal power of the tenth lens to the twelfth lens is Φ10_12, and the focal power of the industrial lens is Φ; Among them, -0.981<Φ1_2 / Φ<-0.782, 0.886<Φ3_7 / Φ<1.144; -0.694<Φ8 / Φ<0.694, -2.047<Φ9 / Φ<0.986; 0.554<Φ10_12 / Φ<1.

620.

2. The industrial lens according to claim 1, characterized in that: The aperture corresponding to the maximum image height of the image side surface of the first lens is D1S2, the radius of curvature of the image side surface of the first lens at the optical axis is R1S2, the aperture corresponding to the maximum image height of the image side surface of the fifth lens is D5S2, the radius of curvature of the image side surface of the fifth lens at the optical axis is R5S2, the aperture corresponding to the maximum image height of the image side surface of the sixth lens is D6S2, the radius of curvature of the image side surface of the sixth lens at the optical axis is R6S2, the aperture corresponding to the maximum image height of the image side surface of the seventh lens is D7S2, and the radius of curvature of the image side surface of the seventh lens at the optical axis is R7S2; wherein, 1.159≤D1S2 / R1S2≤1.505; 0.142≤D5S2 / R5S2≤0.868; 0.113≤D6S2 / R6S2≤1.034; 0.287≤D7S2 / R7S2≤1.

158.

3. The industrial lens according to claim 1, characterized in that: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens form a focusing group, and the tenth lens, the eleventh lens and the twelfth lens form a fixed group.

4. The industrial lens according to claim 1, characterized in that: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens form a focusing group, and the twelfth lens is a fixed group.

5. The industrial lens according to claim 3 or 4, characterized in that: The focal length of the focus group is EFL1, and the focal length of the fixed group is EFL2, wherein 0.787≤EFL1 / EFL2≤1.

051.

6. The industrial lens according to claim 3 or 4, characterized in that: The moving distance of the focusing group is ZOL, the distance from the optical axis center of the image side surface of the twelfth lens to the image plane is BFL; 0.423≤ZOL / BFL≤0.

569.

7. The industrial lens according to claim 1, characterized in that: The refractive index of the first lens is n1, the refractive index of the second lens is n2, the refractive index of the third lens is n3, the refractive index of the fourth lens is n4, the refractive index of the fifth lens is n5, the refractive index of the sixth lens is n6, and the refractive index of the seventh lens is n7; the refractive index of the eighth lens is n8, the refractive index of the ninth lens is n9, the refractive index of the tenth lens is n10, the refractive index of the eleventh lens is n11, and the refractive index of the twelfth lens is n12; Among them, 1.437≤n1≤2.072; 1.347≤n2≤1.869, 1.521≤n3≤2.163; 1.434≤n4≤2.205; 1.434≤n5≤2.075; 1.434≤n6≤1.845; 1.664≤n7≤2.139; 1.346≤n8≤2.134; 1.453≤n9≤2.094; 1.346≤n10≤1.991; 1.625≤n11≤2.079; 1.694≤n12≤2.

210.

8. The industrial lens according to claim 1, characterized in that: The Abbe number of the first lens is v1, the Abbe number of the second lens is v2, the Abbe number of the third lens is v3, the Abbe number of the fourth lens is v4, the Abbe number of the fifth lens is v5, the Abbe number of the sixth lens is v6, and the Abbe number of the seventh lens is v7; the Abbe number of the eighth lens is v8, the Abbe number of the ninth lens is v9, the Abbe number of the tenth lens is v10, the Abbe number of the eleventh lens is v11, and the Abbe number of the twelfth lens is v12; Among them, 37.386≤v1≤99.000; 28.636≤v2≤90.714, 27.781≤v3≤62.528; 25.494≤v4≤75.919; 36.518≤v5≤88.887; 53.198≤v6≤84.304; 14.956≤v7≤33.076; 22.846≤v8≤83.329; 28.318≤v9≤57.502; 20.132≤v10≤99.000; 22.998≤v11≤93.511; 26.562≤v12≤39.

772.

9. The industrial lens according to claim 1, characterized in that: The first lens to the twelfth lens are all glass spherical lenses.

10. The industrial lens according to claim 1, characterized in that: The surface of the lens close to the object plane is the object side surface, and the surface of the lens close to the image plane is the image side surface; The object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; The object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; The object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; The object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; The object side surface of the fifth lens is convex, and the image side surface of the first lens is concave; The object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a concave surface; The object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface; The object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens is a convex surface; The object side surface of the ninth lens is a concave surface, and the image side surface of the ninth lens is a convex surface; The object side surface of the tenth lens is a concave surface, and the image side surface of the tenth lens is a concave surface; The object side surface of the eleventh lens is a concave surface, and the image side surface of the eleventh lens is a convex surface; The object side surface of the twelfth lens is a convex surface, and the image side surface of the twelfth lens is a convex surface.

Images