A high-resolution industrial lens

Abstract

The present application discloses a high-resolution industrial lens, which belongs to the field of optical lenses. The high-resolution industrial lens includes multiple lenses, which are a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens, which are coaxially arranged in sequence from the object side to the image side, each lens having an object-side surface facing the object side and an image-side surface facing the image side; an aperture is provided between the third lens and the fourth lens, and the aperture is coaxially arranged with the multiple lenses; the first lens, the second lens, the fifth lens, the sixth lens, and the seventh lens have positive focal powers, and the third lens, the fourth lens, and the eighth lens have negative focal powers; the industrial lens satisfies the following relationship: ‑6.69≤(R 51 ‑R 52 ) / R 52 ≤‑4.05; 1.78≤(TTL / f)≤1.81; where R 51 is the radius of curvature of the object side of the fifth lens, R 52 is the radius of curvature of the image side of the fifth lens, TTL is the total optical length of the industrial lens, and f is the effective focal length of the industrial lens. This application takes into account both image clarity and lens miniaturization, meets the market's urgent demand for high-performance industrial lenses, and promotes the further development of industrial automation technology.

Description

Technical Field

[0001] The present application relates to the technical field of optical lenses, and in particular to a high-resolution industrial lens. Background Art

[0002] Industrial lenses, as core visual components, play a crucial role in industrial automation systems. Widely used in fields such as machine vision, quality control, and automated manufacturing, they accurately capture image data and provide critical visual feedback to the system. The performance of industrial lenses directly determines the effectiveness of the entire vision system, making their importance self-evident.

[0003] Given the unique characteristics and high demands of industrial applications, industrial lenses must meet even more stringent design standards than conventional lenses. Critical among these are high definition and compact size. High definition ensures the complete presentation of image details and accurate information transmission, and is crucial for improving the recognition accuracy and efficiency of machine vision systems. Furthermore, the advancement of industrial automation technology is driving the demand for even more compact industrial lenses to accommodate increasingly complex and space-constrained production environments.

[0004] However, despite the wide range of industrial lenses available on the market, some still fall short in meeting these high standards. In particular, in the field of industrial lenses, which demand the ultimate in image quality, existing products struggle to fully meet this growing market demand. This not only limits the overall performance of industrial automation systems but also hinders innovation and development in related industries.

[0005] Therefore, developing an industrial lens that combines high definition with compact size is an urgent problem to be solved in this field. Summary of the Invention

[0006] This application provides a high-resolution industrial lens that takes into account both imaging clarity and lens miniaturization, meets the market's urgent demand for high-performance industrial lenses, and promotes the further development of industrial automation technology.

[0007] This application provides a high-resolution industrial lens, which adopts the following technical solution:

[0008] A high-resolution industrial lens, comprising a plurality of lenses, wherein the plurality of lenses are coaxially arranged in sequence from the object side to the image side, namely, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens, each of the lenses having an object-side surface facing the object side and an image-side surface facing the image side;

[0009] An aperture is provided between the third lens and the fourth lens, and the aperture is coaxially arranged with the plurality of lenses;

[0010] The first lens, the second lens, the fifth lens, the sixth lens, and the seventh lens have positive refractive power, and the third lens, the fourth lens, and the eighth lens have negative refractive power;

[0011] Industrial lenses satisfy the following relationship:

[0012] -6.69≤(R 51 -R 52 ) / R 52 ≤-4.05;

[0013] 1.78≤(TTL / f)≤1.81;

[0014] Among them, R 51 is the radius of curvature of the object side of the fifth lens, R 52 is the curvature radius of the image side surface of the fifth lens, TTL is the total optical length of the industrial lens, and f is the effective focal length of the industrial lens.

[0015] By adopting the above technical solution, the curvature radii of the object-side and image-side surfaces of the fifth lens are rationally adjusted, thereby adjusting the lens shape, thereby achieving the high-resolution requirements of industrial lenses and ensuring the quality and clarity of imaging. At the same time, by controlling the relationship between the total optical length and the effective focal length of the industrial lens, the miniaturization of the entire industrial lens is achieved.

[0016] Preferably, the second lens is a biconvex positive lens, the third lens is a biconcave negative lens, and the second lens and the third lens form a first cemented lens group.

[0017] By adopting the above technical solution, the second lens and the third lens are glued together, which can effectively improve the chromatic aberration and distortion of the optical system and reduce the assembly sensitivity of the optical system.

[0018] Preferably, the industrial lens also satisfies the following relationship:

[0019] -2.7≤(f G1 / f)≤-1.8;

[0020] Among them, f G1 is the effective focal length of the first cemented lens group.

[0021] By adopting the above technical solution, the optical power of the first cemented lens group is reasonably distributed, low distortion and low chromatic aberration of the industrial lens are achieved, high-quality imaging is guaranteed, and imaging clarity is improved.

[0022] Preferably, the fourth lens is a biconcave negative lens, the fifth lens is a biconvex positive lens, and the fourth lens and the fifth lens form a second cemented lens group.

[0023] By adopting the above technical solution, the fourth lens and the fifth lens are glued together, which can effectively improve the chromatic aberration and distortion of the optical system and reduce the assembly sensitivity of the optical system.

[0024] Preferably, the industrial lens also satisfies the following relationship:

[0025] -12.2≤(f G2 / f)≤-5.6;

[0026] Among them, f G2 is the effective focal length of the second cemented lens group.

[0027] By adopting the above technical solution, the optical power of the second cemented lens group is reasonably distributed, low distortion and low chromatic aberration of the industrial lens are achieved, high-quality imaging is guaranteed, and imaging clarity is improved.

[0028] Preferably, the industrial lens also satisfies the following relationship:

[0029] 1.04≤|f1 / f|≤1.14;

[0030] 0.75≤|f6 / f|≤0.99;

[0031] Wherein, f1 is the effective focal length of the first lens, and f6 is the effective focal length of the sixth lens.

[0032] By adopting the above technical solution, the effective focal lengths of the first lens and the sixth lens are reasonably set in proportion to the effective focal length of the industrial lens, thereby further improving the resolving power of the industrial lens and enhancing the imaging clarity.

[0033] Preferably, the sixth lens is a biconvex positive lens, and the refractive index of the sixth lens is Nd6, satisfying the following relationship:

[0034] Nd6≥1.74.

[0035] By adopting the above technical solution, the imaging picture is made more uniform, thereby forming a clear image, and at the same time it helps to achieve miniaturization of the lens.

[0036] Preferably, the first lens is a positive meniscus lens convex toward the object, the seventh lens is a positive meniscus lens convex toward the object, and the eighth lens is a biconcave negative lens.

[0037] Preferably, the first lens is a biconvex positive lens, the seventh lens is a meniscus positive lens convex toward the object side, and the eighth lens is a biconcave negative lens.

[0038] Preferably, the first lens is a biconvex positive lens, the seventh lens is a biconvex positive lens, and the eighth lens is a biconcave negative lens.

[0039] By adopting the above technical solution, three feasible lens shape combinations of each lens in the industrial lens are given, providing a basis for the specific implementation of this solution.

[0040] In summary, this application has at least the following beneficial effects:

[0041] 1. This application achieves the high-resolution requirements of industrial lenses by rationally adjusting the curvature radii of the object-side and image-side surfaces of the fifth lens, thereby adjusting the lens shape. This ensures image quality and clarity. Furthermore, by controlling the relationship between the overall optical length and the effective focal length of the industrial lens, the entire industrial lens is miniaturized, enabling it to adapt to complex and space-constrained production environments, thereby promoting the further development of industrial automation technology.

[0042] 2. This application effectively optimizes optical performance, significantly reduces image chromatic aberration, and further achieves lens miniaturization by using cemented lenses in lens design.

[0043] 3. This application optimizes the shape of the lens to reduce lens distortion while maintaining optical performance.

[0044] 4. This application further improves the resolution of the industrial lens and ensures the quality and clarity of the image by reasonably setting the effective focal lengths of the first lens and the sixth lens in the effective focal length of the industrial lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a lens layout diagram of an embodiment of the present application.

[0046] Figure 2 This is the optical path diagram of Example 1 of the present application;

[0047] Figure 3 This is the MFT curve of Example 1 of the present application under visible light 455nm-656nm;

[0048] Figure 4 2 is a schematic diagram of field curvature / distortion of Example 1 of the present application;

[0049] Figure 5 This is a vertical axis chromatic aberration diagram of Example 1 of the present application under visible light 549nm;

[0050] Figure 6 This is an axial aberration diagram of Example 1 of the present application under visible light 455nm-656nm;

[0051] Figure 7 This is the optical path diagram of Example 2 of the present application;

[0052] Figure 8 This is the MFT curve of Example 2 of the present application under visible light 455nm-656nm;

[0053] Figure 9 2 is a schematic diagram of field curvature / distortion of Example 2 of the present application;

[0054] Figure 10 This is a vertical axis chromatic aberration diagram of Example 2 of the present application under visible light 549nm;

[0055] Figure 11 This is an axial aberration diagram of Example 2 of the present application under visible light 455nm-656nm;

[0056] Figure 12 This is the optical path diagram of Example 3 of the present application;

[0057] Figure 13 This is the MFT curve of Example 3 of the present application under visible light 455nm-656nm;

[0058] Figure 14 2 is a schematic diagram of field curvature / distortion of Example 3 of the present application;

[0059] Figure 15 This is a vertical axis chromatic aberration diagram of Example 3 of the present application under visible light 549nm;

[0060] Figure 16 This is an axial aberration diagram of Example 3 of the present application under visible light 455nm-656nm.

[0061] Description of reference numerals:

[0062] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens; 8. Eighth lens; 9. Aperture stop; 10. Protective glass; 11. Imaging surface. DETAILED DESCRIPTION

[0063] The present application provides a high-resolution industrial lens. To make the purpose, technical solutions, and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below.

[0064] The technical solutions in some embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the specification. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0065] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0066] The present application provides a high-resolution industrial lens, comprising a plurality of lenses, wherein the plurality of lenses are a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, and an eighth lens 8, which are coaxially arranged in sequence from the object side to the image side. Each lens has an object-side surface facing the object side and an image-side surface facing the image side.

[0067] A stop 9 (ie, STO) is provided between the third lens 3 and the fourth lens 4 , and the stop 9 is coaxially arranged with the plurality of lenses.

[0068] Aperture 9 improves the imaging quality and the performance of the optical system by limiting the propagation range and direction of the light beam.

[0069] The first lens 1 , the second lens 2 , the fifth lens 5 , the sixth lens 6 and the seventh lens 7 have positive refractive power, and the third lens 3 , the fourth lens 4 and the eighth lens 8 have negative refractive power.

[0070] Industrial lenses satisfy the following relationship:

[0071] -6.69≤(R 51 -R 52 / R 52 )≤-4.05;

[0072] 1.78≤(TTL / f)≤1.81;

[0073] Among them, R 51 is the radius of curvature of the object-side surface of the fifth lens 5;

[0074] R 52 is the curvature radius of the image-side surface of the fifth lens 5;

[0075] TTL is the total optical length of the industrial lens;

[0076] f is the effective focal length of the industrial lens.

[0077] In the embodiments of the present application, controlling the curvature of the fifth lens and thereby adjusting the shape of the lens can achieve the high-resolution requirements of industrial lenses, improve the resolving power of industrial lenses, facilitate capturing more details, make the final image clearer, and improve the image quality.

[0078] The effective focal length f1 of the first lens 1 and the effective focal length f6 of the sixth lens 6 are controlled so that the proportion of the effective focal length f of the entire industrial lens is within the above-specified range.

[0079] In addition, controlling the relationship between the total optical length and the effective focal length f can also meet the demand for miniaturization of industrial lenses and adapt to complex and space-limited production environments.

[0080] In a specific implementation of the present application, the second lens 2 is a biconvex positive lens, the third lens 3 is a biconcave negative lens, and the second lens 2 and the third lens 3 form a first cemented lens group.

[0081] The fourth lens 4 is a biconcave negative lens, the fifth lens 5 is a biconvex positive lens, and the fourth lens 4 and the fifth lens 5 form a second cemented lens group.

[0082] When the second lens 2 and the third lens 3 are glued together, and the fourth lens 4 and the fifth lens 5 are glued together, the industrial lens also satisfies the following relationship:

[0083] -2.7≤(f G1 / f)≤-1.8;

[0084] -12.2≤(f G2 / f)≤-5.6;

[0085] Among them, f G1 is the effective focal length of the first cemented lens group; f G2 is the effective focal length of the second cemented lens group.

[0086] In the embodiment of the present application, the second lens 2 and the third lens 3 are glued to each other, and the fourth lens 4 and the fifth lens 5 are glued to each other, and the optical power of the first glued lens group and the second glued lens group are reasonably distributed according to the above formula. This can effectively improve the chromatic aberration and distortion of the optical system, reduce the assembly sensitivity of the optical system, further enhance the clarity of the image, achieve low distortion and low chromatic aberration of the industrial lens, and ensure high-quality imaging.

[0087] In summary, the second lens 2, the third lens 3, the fourth lens 4, and the fifth lens 5 are all cemented lenses. In order to further improve the clarity of the image, this embodiment reasonably allocates the effective focal lengths of the first lens 1 and the sixth lens 6 adjacent to the above-mentioned cemented lens to the proportion of the effective focal length of the entire industrial lens, thereby further improving the resolving power of the industrial lens and thus improving the image clarity.

[0088] Specifically, the effective focal length f1 of the first lens 1 of the industrial lens, the effective focal length f6 of the sixth lens 6, and the effective focal length f of the industrial lens satisfy the following relationship:

[0089] 1.04≤|f1 / f|≤1.14;

[0090] 0.75≤|f6 / f|≤0.99.

[0091] Through the above relationship, the resolving power of the industrial lens is improved, the imaging clarity is further improved, the imaging quality is guaranteed, and the optical performance of the industrial lens is optimized.

[0092] In one specific implementation of the present application, the sixth lens 6 is a biconvex positive lens, and the refractive index of the sixth lens 6 is Nd6, which satisfies the following relationship:

[0093] Nd6≥1.74.

[0094] By controlling the refractive index of the sixth lens 6 , the imaging picture is made more uniform, thereby forming a clear image, and at the same time helps to achieve miniaturization of the lens.

[0095] In this embodiment, the use of thermally resistant glass can effectively improve the stability of the lens assembly.

[0096] All lenses of this embodiment are made of glass material with a conventional refractive index, which effectively reduces the cost.

[0097] In an embodiment of the present application, the industrial lens is provided with a first lens 1, a second lens 2, a third lens 3, an aperture 9, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a protective glass 10 and an imaging surface 11 in sequence along the optical axis from the object side to the image side.

[0098] The first lens 1 has positive refractive power, and its curved shape helps the lens to capture light at a large angle and expand the viewing angle.

[0099] The second lens 2 is a biconvex positive lens, and the third lens 3 is a biconcave negative lens. The two are glued together to eliminate or balance the chromatic aberration and distortion produced by the lens, reduce tolerance sensitivity, and improve imaging quality.

[0100] The aperture 9 can control the imaging quality and the performance of the optical system by limiting the propagation range and direction of the light beam.

[0101] The fourth lens 4 is a biconcave negative lens, and the fifth lens 5 is a biconvex positive lens. The two are glued together to eliminate or balance the chromatic aberration and distortion produced by the lens, reduce tolerance sensitivity, and improve imaging quality.

[0102] At the same time, in a specific embodiment, the fifth lens 5 reasonably controls the optical focal length so that the total optical length TTL is less than or equal to 60.06 mm, thereby further meeting the miniaturization requirements of the lens.

[0103] The sixth lens 6 is a biconvex positive lens, which is used to compress the light collected by the fifth lens 5 so that the light can be smoothly transferred to the rear optical system, making the picture brightness more uniform and further improving the imaging quality.

[0104] The seventh lens 7 has positive optical power and is used to focus the light collected by the sixth lens 6, which is beneficial to the field correction of the lens, optimizes the imaging performance of the lens group, and improves the imaging quality.

[0105] The eighth lens 8 is a biconcave negative lens, which is used to diverge the light collected by the seventh lens 7 and correct the aberration, thereby optimizing the imaging performance of the lens group and improving the imaging quality.

[0106] In order to explain the above solution more clearly, three different embodiments that comply with the above solution are given below.

[0107] Example 1:

[0108] This embodiment provides a high-resolution industrial lens, such as Figure 2 As shown, in this embodiment, the first lens 1 is a meniscus positive lens convex toward the object, the second lens 2 is a biconvex positive lens, the third lens 3 is a biconcave negative lens, the fourth lens 4 is a biconcave negative lens, the fifth lens 5 is a biconvex positive lens, the sixth lens 6 is a biconvex positive lens, the seventh lens 7 is a meniscus positive lens convex toward the object, and the eighth lens 8 is a biconcave negative lens.

[0109] Based on the structure of the industrial lens provided above, the industrial lens includes, from the object side to the image side, a meniscus positive lens convex toward the object side, a double convex positive lens, a double concave negative lens, an aperture 9, a double concave negative lens, a double convex positive lens, a double convex positive lens, a meniscus positive lens convex toward the object side, a double concave negative lens, a protective glass 10, and an imaging surface 11, which are arranged coaxially in sequence.

[0110] Table 1 shows various parameters of multiple lenses of the industrial lens in this embodiment 1.

[0111] Table 1:

[0112]

[0113]

[0114] Combine Figure 1 and Figure 2 As shown, the first lens 1 of this embodiment, i.e., a positive meniscus lens convex toward the object side, has a convex object-side surface S1 and a concave image-side surface S2;

[0115] The second lens 2, i.e., a biconvex positive lens, has a convex object-side surface S3 and a convex image-side surface S4.

[0116] The object-side surface S4 of the third lens element 3, i.e., the biconcave negative lens, is concave, and the image-side surface S5 is concave;

[0117] The second lens 2 and the third lens 3 are cemented together and share S4. Therefore, S4 is convex relative to the second lens 2 and concave relative to the third lens 3.

[0118] The fourth lens element 4, i.e., a biconcave negative lens, has a concave object-side surface S7 and a concave image-side surface S8.

[0119] The fifth lens element 5, i.e., a biconvex positive lens, has a convex object-side surface S8 and a convex image-side surface S9.

[0120] The fourth lens 4 and the fifth lens 5 are cemented together and share S8. Therefore, S8 is concave relative to the fourth lens 4 and convex relative to the fifth lens 5.

[0121] The sixth lens element 6, i.e., a biconvex positive lens, has an object-side surface S10 that is convex, and an image-side surface S11 that is convex.

[0122] The seventh lens element 7, i.e., a positive meniscus lens convex toward the object, has a convex object-side surface S12 and a concave image-side surface S13.

[0123] The object-side surface S14 of the eighth lens element 8, i.e., the biconcave negative lens, is concave, and the image-side surface S15 is concave.

[0124] S16 and S17 are two sides of the protective glass 10;

[0125] IMA is the imaging surface 11 .

[0126] In this embodiment, the parameters of the industrial lens are shown in Table 2.

[0127] Table 2:

[0128]

[0129]

[0130] As can be seen from Table 2 above, in this embodiment, the curvature radius R of the object side surface of the fifth lens 5 is 51 The curvature radius R of the image side 52 The relationship between: (R 51 -R 52 ) / R 52 =-6.6857, satisfying -6.69≤(R 51 -R 52 ) / R 52 ≤-4.05;

[0131] The relationship between the total optical length TTL and the effective focal length f of an industrial lens is: TTL / f=1.7888, satisfying 1.78≤(TTL / f)≤1.81;

[0132] The effective focal length f of the first cemented lens group G1 The relationship between the effective focal length f of the industrial lens: f G1 / f=-1.8666, satisfying -2.7≤(f G1 / f)≤-1.8;

[0133] The effective focal length f of the second cemented lens group G2 The relationship between the effective focal length f of the industrial lens: f G2 / f=-5.6764, satisfying -12.2≤(f G2 / f)≤-5.6;

[0134] The relationship between the effective focal length f1 of the first lens 1 and the effective focal length f of the industrial lens is: |f1 / f|=1.1032, satisfying 1.04≤|f1 / f|≤1.14;

[0135] The relationship between the effective focal length f6 of the sixth lens 6 and the effective focal length f of the industrial lens is: |f6 / f|=0.9825, satisfying 0.75≤|f6 / f|≤0.99;

[0136] The refractive index of the sixth lens 6 is Nd6=1.7440, satisfying Nd6≥1.74.

[0137] like Figure 3 The figure shows the MTF graph of this embodiment. Curves of different colors represent different fields of view. It can be seen that the MTF values of each field of view are relatively concentrated. The imaging quality of this industrial lens is very uniform from the center to the edge of the field of view, that is, the entire image is very clear. At 60lp / mm, the optical transfer function is greater than 0.6, and the image clarity is guaranteed.

[0138] Figure 4 This is the field curvature / distortion diagram of this embodiment. The left part shows the field curvature. As can be seen from the figure, the field curvature values are all controlled within ±0.1mm, indicating that the field curvature of the industrial lens is well corrected. The right part shows the distortion, where the horizontal axis represents the distortion magnitude. As can be seen from the figure, the distortion value is controlled within -1.4%, indicating that the distortion of the industrial lens is well corrected and the distortion of the imaging image is well controlled, ensuring the clarity and quality of the image.

[0139] Figure 5 This is a diagram of vertical chromatic aberration for this embodiment, showing the chromatic aberration of each wavelength at different image heights on the imaging plane. As can be seen from the figure, the vertical chromatic aberration between the shortest and longest wavelengths is controlled within ±0.6μm, indicating that the industrial lens can effectively correct chromatic aberration in the peripheral field of view and has high image color reproduction within the diffraction range, ensuring image clarity and quality.

[0140] Figure 6 This is the axial aberration diagram of this embodiment. It can be seen from the figure that the axial aberration of the shortest wavelength and the longest wavelength is controlled within ±0.1mm, indicating that the axial aberration of the industrial lens is well corrected, ensuring the clarity and quality of the imaging.

[0141] Depend on Figure 3-Figure 6 It can be seen that this embodiment has the advantages of low distortion, low chromatic aberration, and high resolution, which ensures the clarity of the imaging, can achieve better imaging effects, and has good optical performance.

[0142] Example 2:

[0143] This embodiment provides a high-resolution industrial lens, such as Figure 7 As shown, in this embodiment, the first lens 1 is a biconvex positive lens, the second lens 2 is a biconvex positive lens, the third lens 3 is a biconcave negative lens, the fourth lens 4 is a biconcave negative lens, the fifth lens 5 is a biconvex positive lens, the sixth lens 6 is a biconvex positive lens, the seventh lens 7 is a meniscus positive lens convex toward the object side, and the eighth lens 8 is a biconcave negative lens.

[0144] Based on the structure of the industrial lens provided above, the industrial lens includes a biconvex positive lens, a biconvex positive lens, a biconcave negative lens, an aperture 9, a biconcave negative lens, a biconvex positive lens, a biconvex positive lens, a meniscus positive lens convex toward the object side, a biconcave negative lens, a protective glass 10 and an imaging surface 11 arranged coaxially from the object side to the image side.

[0145] Table 3 shows various parameters of multiple lenses of the industrial lens in this embodiment 2.

[0146] Table 3:

[0147]

[0148]

[0149] Combine Figure 1 and Figure 7 As shown, the object-side surface S1 of the first lens element 1 of this embodiment, i.e., the biconvex positive lens, is convex, and the image-side surface S2 is convex;

[0150] The second lens 2, i.e., a biconvex positive lens, has a convex object-side surface S3 and a convex image-side surface S4.

[0151] The object-side surface S4 of the third lens element 3, i.e., the biconcave negative lens, is concave, and the image-side surface S5 is concave;

[0152] The second lens 2 and the third lens 3 are cemented together and share S4. Therefore, S4 is convex relative to the second lens 2 and concave relative to the third lens 3.

[0153] The fourth lens element 4, i.e., a biconcave negative lens, has a concave object-side surface S7 and a concave image-side surface S8.

[0154] The fifth lens element 5, i.e., a biconvex positive lens, has a convex object-side surface S8 and a convex image-side surface S9.

[0155] The fourth lens 4 and the fifth lens 5 are cemented together and share S8. Therefore, S8 is concave relative to the fourth lens 4 and convex relative to the fifth lens 5.

[0156] The sixth lens element 6, i.e., a biconvex positive lens, has an object-side surface S10 that is convex, and an image-side surface S11 that is convex.

[0157] The seventh lens element 7, i.e., a positive meniscus lens convex toward the object, has a convex object-side surface S12 and a concave image-side surface S13.

[0158] The object-side surface S14 of the eighth lens element 8, i.e., the biconcave negative lens, is concave, and the image-side surface S15 is concave.

[0159] S16 and S17 are two sides of the protective glass 10;

[0160] IMA is the imaging surface 11 .

[0161] In this embodiment, the parameters of the industrial lens are shown in Table 4.

[0162] Table 4:

[0163] <![CDATA[f G1 ]]> -71.8084 <![CDATA[f G2 ]]> -397.4813 f 32.6501 <![CDATA[f1]]> 33.995117 <![CDATA[f6]]> 24.596693 TTL 58.4751 <![CDATA[R 51 ]]> 83.5233 <![CDATA[R 52 ]]> -17.9243 <![CDATA[Nd6]]> 1.7440

[0164] As can be seen from Table 4 above, in this embodiment, the curvature radius R of the object side surface of the fifth lens 5 is 51 The curvature radius R of the image side 52 The relationship between: (R 51 -R 52 ) / R 52 =-5.6598, satisfying -6.69≤(R 51 -R 52 ) / R 52 ≤-4.05;

[0165] The relationship between the total optical length TTL and the effective focal length f of an industrial lens is: TTL / f=1.7910, satisfying 1.78≤(TTL / f)≤1.81;

[0166] The effective focal length f of the first cemented lens group G1 The relationship between the effective focal length f of the industrial lens: f G1 / f=-2.1993, satisfying -2.7≤(f G1 / f)≤-1.8;

[0167] The effective focal length f of the second cemented lens group G2 The relationship between the effective focal length f of the industrial lens: f G2 / f=-12.1740, satisfying -12.2≤(f G2 / f)≤-5.6;

[0168] The relationship between the effective focal length f1 of the first lens 1 and the effective focal length f of the industrial lens is: |f1 / f|=1.0412, satisfying 1.04≤|f1 / f|≤1.14;

[0169] The relationship between the effective focal length f6 of the sixth lens 6 and the effective focal length f of the industrial lens is: |f6 / f|=0.7533, satisfying 0.75≤|f6 / f|≤0.99;

[0170] The refractive index of the sixth lens 6 is Nd6=1.7440, satisfying Nd6≥1.74.

[0171] like Figure 8 The figure shows the MTF graph of this embodiment. Curves of different colors represent different fields of view. It can be seen that the MTF values of each field of view are relatively concentrated. The imaging quality of this industrial lens is very uniform from the center to the edge of the field of view, that is, the entire image is very clear. At 60lp / mm, the optical transfer function is greater than 0.65, and the image clarity is guaranteed.

[0172] Figure 9 This is the field curvature / distortion diagram of this embodiment. The left part shows the field curvature. As can be seen from the figure, the field curvature values are all controlled within ±0.08mm, indicating that the field curvature of the industrial lens is well corrected. The right part shows the distortion, where the horizontal axis represents the distortion magnitude. As can be seen from the figure, the distortion value is controlled within 0.08%, indicating that the distortion of the industrial lens is well corrected and the distortion of the imaging image is well controlled, ensuring the clarity and quality of the imaging.

[0173] Figure 10 This is a diagram of vertical chromatic aberration for this embodiment, showing the chromatic aberration of each wavelength at different image heights on the imaging plane. As can be seen from the diagram, the vertical chromatic aberration between the shortest and longest wavelengths is controlled within ±2.5μm, indicating that the industrial lens can effectively correct chromatic aberration in the peripheral field of view and has high image color reproduction within the diffraction range, ensuring image clarity and quality.

[0174] Figure 11 This is the axial aberration diagram of this embodiment. It can be seen from the figure that the axial aberration of the shortest wavelength and the longest wavelength is controlled within ±0.08mm, indicating that the axial aberration of the industrial lens is well corrected, ensuring the clarity and quality of the imaging.

[0175] Depend on Figures 8-11 It can be seen that this embodiment has the advantages of low distortion, low chromatic aberration, and high resolution, which ensures the clarity of the imaging, can achieve better imaging effects, and has good optical performance.

[0176] Example 3:

[0177] This embodiment provides a high-resolution industrial lens, such as Figure 12 As shown, in this embodiment, the first lens 1 is a biconvex positive lens, the second lens 2 is a biconvex positive lens, the third lens 3 is a biconcave negative lens, the fourth lens 4 is a biconcave negative lens, the fifth lens 5 is a biconvex positive lens, the sixth lens 6 is a biconvex positive lens, the seventh lens 7 is a biconvex positive lens, and the eighth lens 8 is a biconcave negative lens.

[0178] Based on the structure of the industrial lens provided above, the industrial lens includes a biconvex positive lens, a biconvex positive lens, a biconcave negative lens, an aperture 9, a biconcave negative lens, a biconvex positive lens, a biconvex positive lens, a biconvex positive lens, a biconvex positive lens, a biconcave negative lens, a protective glass 10 and an imaging surface 11 arranged coaxially from the object side to the image side.

[0179] Table 5 shows various parameters of multiple lenses of the industrial lens in this embodiment 3.

[0180] Table 5:

[0181]

[0182]

[0183] Combine Figure 1 and Figure 12 As shown, the object-side surface S1 of the first lens element 1 of this embodiment, i.e., the biconvex positive lens, is convex, and the image-side surface S2 is convex;

[0184] The second lens 2, i.e., a biconvex positive lens, has a convex object-side surface S3 and a convex image-side surface S4.

[0185] The object-side surface S4 of the third lens element 3, i.e., the biconcave negative lens, is concave, and the image-side surface S5 is concave;

[0186] The second lens 2 and the third lens 3 are cemented together and share S4. Therefore, S4 is convex relative to the second lens 2 and concave relative to the third lens 3.

[0187] The fourth lens element 4, i.e., a biconcave negative lens, has a concave object-side surface S7 and a concave image-side surface S8.

[0188] The fifth lens element 5, i.e., a biconvex positive lens, has a convex object-side surface S8 and a convex image-side surface S9.

[0189] The fourth lens 4 and the fifth lens 5 are cemented together and share S8. Therefore, S8 is concave relative to the fourth lens 4 and convex relative to the fifth lens 5.

[0190] The sixth lens element 6, i.e., a biconvex positive lens, has an object-side surface S10 that is convex, and an image-side surface S11 that is convex.

[0191] The seventh lens element 7, i.e., a biconvex positive lens, has a convex object-side surface S12 and a convex image-side surface S13.

[0192] The object-side surface S14 of the eighth lens element 8, i.e., the biconcave negative lens, is concave, and the image-side surface S15 is concave.

[0193] S16 and S17 are two sides of the protective glass 10;

[0194] IMA is the imaging surface 11 .

[0195] In this embodiment, the parameters of the industrial lens are shown in Table 6.

[0196] Table 6:

[0197] <![CDATA[f G1 ]]> -85.2346 <![CDATA[f G2 ]]> -190.5752 f 32.5526 <![CDATA[f1]]> 36.820647 <![CDATA[f6]]> 29.840537 TTL 58.6601 <![CDATA[R 51 ]]> 64.1769 <![CDATA[R 52 ]]> -21.0113 <![CDATA[Nd6]]> 1.7440

[0198] As can be seen from Table 6 above, in this embodiment, the curvature radius R of the object side surface of the fifth lens 5 is 51 The curvature radius R of the image side 52 The relationship between: (R 51 -R 52 ) / R 52 =-4.0544, satisfying -6.69≤(R 51 -R 52 ) / R 52 ≤-4.05;

[0199] The relationship between the total optical length TTL and the effective focal length f of an industrial lens is: TTL / f=1.8020, satisfying 1.78≤(TTL / f)≤1.81;

[0200] The effective focal length f of the first cemented lens group G1 The relationship between the effective focal length f of the industrial lens: f G1 / f=-2.6184, satisfying -2.7≤(f G1 / f)≤-1.8;

[0201] The effective focal length f of the second cemented lens group G2 The relationship between the effective focal length f of the industrial lens: f G2 / f=-5.8544, satisfying -12.2≤(f G2 / f)≤-5.6;

[0202] The relationship between the effective focal length f1 of the first lens 1 and the effective focal length f of the industrial lens is: |f1 / f|=1.1311, satisfying 1.04≤|f1 / f|≤1.14;

[0203] The relationship between the effective focal length f6 of the sixth lens 6 and the effective focal length f of the industrial lens is: |f6 / f|=0.9167, satisfying 0.75≤|f6 / f|≤0.99;

[0204] The refractive index of the sixth lens 6 is Nd6=1.7440, satisfying Nd6≥1.74.

[0205] like Figure 13 The figure shows the MTF graph of this embodiment. Curves of different colors represent different fields of view. It can be seen that the MTF values of each field of view are relatively concentrated. The imaging quality of this industrial lens is very uniform from the center to the edge of the field of view, that is, the entire image is very clear. At 60lp / mm, the optical transfer function is greater than 0.6, and the image clarity is guaranteed.

[0206] Figure 14 This is the field curvature / distortion diagram of this embodiment. The left part represents the field curvature. As can be seen from the figure, the field curvature values are all controlled within ±0.1mm, indicating that the field curvature of the industrial lens is well corrected. The right part represents the distortion, where the horizontal axis represents the distortion size. As can be seen from the figure, the distortion value is controlled within 0.05%, indicating that the distortion of the industrial lens is well corrected and the distortion of the imaging image is well controlled, ensuring the clarity and quality of the image.

[0207] Figure 15 This is a diagram of vertical chromatic aberration for this embodiment, showing the chromatic aberration of each wavelength at different image heights on the imaging plane. As can be seen from the figure, the vertical chromatic aberration of the shortest and longest wavelengths is controlled within ±2μm, indicating that the industrial lens can effectively correct chromatic aberration in the peripheral field of view and has high image color reproduction within the diffraction range, ensuring image clarity and quality.

[0208] Figure 16 This is the axial aberration diagram of this embodiment. It can be seen from the figure that the axial aberration of the shortest wavelength and the longest wavelength is controlled within ±0.1mm, indicating that the axial aberration of the industrial lens is well corrected, ensuring the clarity and quality of the imaging.

[0209] Depend on Figure 13-16 It can be seen that this embodiment has the advantages of low distortion, low chromatic aberration, and high resolution, which ensures the clarity of the imaging, can achieve better imaging effects, and has good optical performance.

[0210] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A high-resolution industrial lens, characterized by: The invention comprises a plurality of lenses, wherein the plurality of lenses are a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5), a sixth lens (6), a seventh lens (7) and an eighth lens (8) which are coaxially arranged in sequence from the object side to the image side, and each of the lenses has an object-side surface facing the object side and an image-side surface facing the image side; An aperture (9) is provided between the third lens (3) and the fourth lens (4), and the aperture (9) is coaxially arranged with the plurality of lenses; The first lens (1), the second lens (2), the fifth lens (5), the sixth lens (6) and the seventh lens (7) have positive optical power, and the third lens (3), the fourth lens (4) and the eighth lens (8) have negative optical power; Industrial lenses satisfy the following relationship: -6.69≤(R 51 -R 52 ) / R 52 ≤-4.05; 1.78≤(TTL / f)≤1.81; Among them, R 51 is the curvature radius of the object side of the fifth lens (5), R 52 is the curvature radius of the image side surface of the fifth lens (5), TTL is the total optical length of the industrial lens, and f is the effective focal length of the industrial lens.

2. The high-resolution industrial lens according to claim 1, characterized in that: The second lens (2) is a biconvex positive lens, the third lens (3) is a biconcave negative lens, and the second lens (2) and the third lens (3) form a first cemented lens group.

3. The high-resolution industrial lens according to claim 2, characterized in that: The industrial lens also satisfies the following relationship: -2.7≤(f G1 / f)≤-1.8; Among them, f G1 is the effective focal length of the first cemented lens group.

4. The high-resolution industrial lens according to claim 1, characterized in that: The fourth lens (4) is a double-concave negative lens, the fifth lens (5) is a double-convex positive lens, and the fourth lens (4) and the fifth lens (5) form a second cemented lens group.

5. The high-resolution industrial lens according to claim 4, characterized in that: The industrial lens also satisfies the following relationship: -12.2≤(f G2 / f)≤-5.6; Among them, f G2 is the effective focal length of the second cemented lens group.

6. The high-resolution industrial lens according to claim 1, characterized in that: The industrial lens also satisfies the following relationship: 1.04≤|f1 / f|≤1.14; 0.75≤|f6 / f|≤0.99; Wherein, f1 is the effective focal length of the first lens (1), and f6 is the effective focal length of the sixth lens (6).

7. The high-resolution industrial lens according to claim 1, characterized in that: The sixth lens (6) is a biconvex positive lens, and the refractive index of the sixth lens (6) is Nd6, which satisfies the following relationship: Nd6≥1.

74.

8. The high-resolution industrial lens according to claim 1, characterized in that: The first lens (1) is a positive meniscus lens convex toward the object side, the seventh lens (7) is a positive meniscus lens convex toward the object side, and the eighth lens (8) is a double concave negative lens.

9. The high-resolution industrial lens according to claim 1, characterized in that: The first lens (1) is a biconvex positive lens, the seventh lens (7) is a meniscus positive lens convex toward the object side, and the eighth lens (8) is a biconcave negative lens.

10. The high-resolution industrial lens according to claim 1, characterized in that: The first lens (1) is a biconvex positive lens, the seventh lens (7) is a biconvex positive lens, and the eighth lens (8) is a biconcave negative lens.

Images