An industrial lens

Abstract

The present application discloses an industrial lens, which includes a first lens group and a second lens group coaxially arranged in sequence from the object side to the image side. A diaphragm is arranged between the first lens group and the second lens group; the first lens group includes a front lens group, and the front lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object side to the image side. The first lens group further includes a fifth lens, and the fifth lens is located on the image side of the fourth lens; the second lens group includes a sixth lens, a seventh lens, an eighth lens, and a ninth lens; the industrial lens satisfies the following relational expressions: |f u1 / f| ≤ 5.8; |f u2 / f| ≥ 1.8; SD max / TTL ≤ 0.36; where f u1 is the effective focal length of the first lens group in the industrial lens, f u2 is the effective focal length of the second lens group in the industrial lens, f is the effective focal length of the industrial lens, SD max is the clear aperture of the largest lens in the industrial lens, and TTL is the overall optical length of the industrial lens. The present application can improve the imaging quality and at the same time meet the industrial requirements of miniaturization.

Description

Technical Field

[0001] The present application relates to the field of optical lenses, and in particular to an industrial lens. Background Art

[0002] In industrial automation systems, industrial lenses play a vital role as key components for capturing real-time data on production sites. Their performance directly determines the accuracy and reliability of information obtained by the system. Given the particularity of the industrial environment, industrial lenses often need to perform far better than ordinary lenses, including but not limited to: ensuring high definition and imaging quality of captured images, and designing a more compact size to adapt to complex and changing industrial environments.

[0003] On the one hand, ensuring that the high resolution of industrial lenses can capture tiny and critical production details is the key to ensuring clear image details and complete information, which requires industrial lenses to have excellent optical performance. On the other hand, high relative illumination lenses can maintain image consistency and readability in complex lighting environments, which also affects image clarity and is also crucial to ensuring the accuracy and stability of production monitoring. In addition, as industrial automation equipment develops towards a more compact and efficient direction, miniaturization has become an important trend in industrial lens design, which requires lenses to be as small as possible while maintaining high performance to adapt to increasingly compact equipment layouts.

[0004] However, although there are many industrial lens products on the market, they still have obvious shortcomings in meeting the above-mentioned specific high-performance requirements at the same time. Therefore, developing an industrial lens that can overcome the defects of existing technologies and has the characteristics of high resolution, high relative illumination and miniaturization has become an urgent need to promote the advancement of industrial automation technology and industrial upgrading. Summary of the invention

[0005] In order to promote the overall improvement of production efficiency and product quality in the industrial production process, the present application provides an industrial lens that can ensure high-definition images, improve imaging quality, and meet the industrial needs of miniaturization.

[0006] The industrial lens provided in this application adopts the following technical solution:

[0007] An industrial lens comprises a first lens group and a second lens group coaxially arranged in sequence from an object side to an image side, wherein an aperture is arranged between the first lens group and the second lens group;

[0008] The first lens group includes a front lens group, the front lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object side to the image side, the first lens group further includes a fifth lens, and the fifth lens is located on the image side of the fourth lens;

[0009] The second lens group includes a sixth lens, a seventh lens, an eighth lens, and a ninth lens;

[0010] This industrial lens satisfies the following relational expressions,

[0011] |f u1 / f| ≤ 5.8;

[0012] |f u2 / f| ≥ 1.8;

[0013] SD max / TTL ≤ 0.36;

[0014] Wherein, f u1 is the effective focal length of the first lens group in the industrial lens, f u2 is the effective focal length of the second lens group in the industrial lens, f is the effective focal length of the industrial lens, SD max is the clear aperture of the largest lens in the industrial lens, and TTL is the optical total length of the industrial lens.

[0015] By adopting the above technical solution, the industrial lens is divided into two lens groups, and the ratios of the effective focal lengths of the two lens groups to the effective focal length of the whole lens are reasonably allocated, so as to achieve high relative illumination and high resolution of the optical system. The incident light is controlled through the clear aperture to further achieve high relative illumination. At the same time, the ratio of the clear aperture of the largest lens in the industrial lens to the optical total length is controlled to realize the miniaturization of the whole lens.

[0016] Preferably, the industrial lens also satisfies the following relational expressions,

[0017] 3.3 ≤ FOV / CRA ≤ 3.6;

[0018] Wherein, FOV is the maximum field of view angle of the industrial lens, and CRA is the principal ray angle of the optical system formed by the industrial lens.

[0019] By adopting the above technical solution, the positions of the lenses in the optical system are reasonably allocated, so as to control the ratio between the maximum field of view angle and the principal ray angle, meet the requirement of low distortion imaging, and further improve the imaging quality.

[0020] Preferably, the sixth lens is a biconvex positive lens, the seventh lens is a biconcave negative lens, and the sixth lens and the seventh lens are cemented lenses.

[0021] By adopting the above technical solution, the sixth lens and the seventh lens are cemented lenses, which are used to eliminate or balance the chromatic aberration and distortion generated by the lens, reduce the tolerance sensitivity, and improve the imaging quality.

[0022] Preferably, the industrial lens satisfies the following relationship:

[0023] 32.8 ≤ |VD6 - VD7|;

[0024] wherein, VD6 is the Abbe number of the sixth lens, and VD7 is the Abbe number of the seventh lens.

[0025] By adopting the above technical solution, by reasonably selecting the Abbe numbers of the sixth lens and the seventh lens that make up the cemented lens, the chromatic aberration of the optical system can be effectively reduced, and the imaging quality can be improved.

[0026] Preferably, the industrial lens satisfies the following relationship:

[0027] Nd5 ≥ 1.8;

[0028] wherein, Nd5 is the refractive index of the fifth lens.

[0029] By adopting the above technical solution, by using a material with a high refractive index for the fifth lens and controlling the optical power of the fifth lens, the miniaturization of the optical lens can be further realized.

[0030] Preferably, the industrial lens satisfies the following relationship:

[0031] Nd9 ≤ 1.8; VD9 ≥ 47.9;

[0032] wherein, Nd9 is the refractive index of the ninth lens, and VD9 is the Abbe number of the ninth lens.

[0033] By adopting the above technical solution, by controlling the Abbe number and refractive index of the ninth lens and selecting a suitable combination of Abbe number and refractive index, it helps to reduce the aberration and distortion of the lens, and can ensure that the lens can provide clear and accurate imaging effects under various light conditions.

[0034] Preferably, the first lens of the front lens group is a biconvex positive lens, the second lens is a meniscus positive lens convex toward the object side, the third lens is a biconcave negative lens, and the fourth lens is a meniscus positive lens convex toward the image side.

[0035] Preferably, the fifth lens is a meniscus positive lens convex toward the object side, the eighth lens is a plano-convex positive lens convex toward the image side, and the ninth lens is a biconvex positive lens.

[0036] Preferably, the fifth lens is a biconvex positive lens, the eighth lens is a plano-convex positive lens convex toward the image side, and the ninth lens is a plano-convex positive lens convex toward the object side.

[0037] Preferably, the fifth lens is a biconvex positive lens, the eighth lens is a plano-convex positive lens convex toward the image side, and the ninth lens is a meniscus positive lens convex toward the object side.

[0038] By adopting the above technical solutions, the lens shapes of the fifth lens and the ninth lens are adjusted, and three different implementable lens shape combinations in the industrial lens are given, providing a basis for the specific implementation of this solution.

[0039] In summary, the present application has at least the following beneficial effects:

[0040] 1. The industrial lens of the present application is divided into two lens groups, and the ratios of the effective focal lengths of the two lens groups to the effective focal length of the entire lens are reasonably allocated, so as to achieve high relative illumination and high resolution of the optical system, improve the imaging clarity and quality; at the same time, control the ratio of the light passing aperture of the largest lens in the industrial lens to the optical total length to achieve the miniaturization of the entire lens.

[0041] 2. By reasonably allocating the positions of the lenses in the optical system, the present application controls the ratio between the maximum field angle and the chief ray angle, while meeting the requirement of low distortion, maintaining the optical performance of the lens, and further improving the imaging quality.

[0042] 3. By introducing a cemented lens into the imaging system and controlling the Abbe number of the cemented lens, the present invention reduces the chromatic aberration of imaging and further realizes the miniaturization of the lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a lens layout diagram of an industrial lens of the present application;

[0044] Figure 2 is the optical path diagram of Embodiment 1 of the present application;

[0045] Figure 3 is the MTF curve diagram of Embodiment 1 of the present application under visible light of 450 nm - 656 nm;

[0046] Figure 4 is the field curvature / distortion diagram of Embodiment 1 of the present application under visible light of 450 nm - 656 nm;

[0047] Figure 5 is the longitudinal aberration diagram of Embodiment 1 of the present application under visible light of 450 nm - 656 nm;

[0048] Figure 6It is the lateral chromatic aberration diagram of Embodiment 1 of the present application at 656 nm of visible light;

[0049] Figure 7 It is the relative illuminance diagram of Embodiment 1 of the present application at 656 nm of visible light;

[0050] Figure 8 It is the optical path diagram of Embodiment 2 of the present application;

[0051] Figure 9 It is the MTF curve diagram of Embodiment 2 of the present application at visible light of 450 nm - 656 nm;

[0052] Figure 10 It is the field curvature / distortion diagram of Embodiment 2 of the present application at visible light of 450 nm - 656 nm;

[0053] Figure 11 It is the longitudinal aberration diagram of Embodiment 2 of the present application at visible light of 450 nm - 656 nm;

[0054] Figure 12 It is the lateral chromatic aberration diagram of Embodiment 2 of the present application at 656 nm of visible light;

[0055] Figure 13 It is the relative illuminance diagram of Embodiment 2 of the present application at 656 nm of visible light;

[0056] Figure 14 It is the optical path diagram of Embodiment 3 of the present application;

[0057] Figure 15 It is the MTF curve diagram of Embodiment 3 of the present application at visible light of 450 nm - 656 nm;

[0058] Figure 16 It is the field curvature / distortion diagram of Embodiment 3 of the present application at visible light of 450 nm - 656 nm;

[0059] Figure 17 It is the longitudinal aberration diagram of Embodiment 3 of the present application at visible light of 450 nm - 656 nm;

[0060] Figure 18 It is the lateral chromatic aberration diagram of Embodiment 3 of the present application at 656 nm of visible light;

[0061] Figure 19 It is the relative illuminance diagram of Embodiment 3 of the present application at 656 nm of visible light.

[0062] Explanation of reference numerals:

[0063] 1. First lens group; 2. Second lens group; 3. Diaphragm; 4. First lens; 5. Second lens; 6. Third lens; 7. Fourth lens; 8. Fifth lens; 9. Sixth lens; 10. Seventh lens; 11. Eighth lens; 12. Ninth lens; 13. Protective glass; 14. Imaging surface. Detailed implementation manners

[0064] This application provides an industrial lens. To make the objectives, technical solutions, and advantages of this application clearer, the following will further elaborate on the implementation manners of this application in detail.

[0065] The following will clearly and completely describe the technical solutions in some embodiments of this application with reference to the accompanying drawings of the specification. Obviously, the described embodiments are only some embodiments of this application, rather than all embodiments.

[0066] It should be noted that in this specification, the expressions such as first, second, and third are only used to distinguish one feature from another, and do not represent any limitation on the features. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0067] As Figure 1 shown, this application proposes an industrial lens, which includes a first lens group 1 and a second lens group 2 coaxially arranged in sequence from the object side to the image side. A diaphragm 3 is arranged between the first lens group 1 and the second lens group 2;

[0068] The industrial lens is divided into two lens groups, namely the first lens group 1 and the second lens group 2, which is convenient for separately controlling the optical power, so as to allocate the positions or parameters of each lens to improve the optical performance.

[0069] The first lens group 1 includes a pre-sequence lens group, and the pre-sequence lens group includes a first lens 4, a second lens 5, a third lens 6, and a fourth lens 7 arranged in sequence from the object side to the image side.

[0070] In the embodiments of this application, the first lens 4 of the pre-sequence lens group is a biconvex positive lens, the second lens 5 is a meniscus positive lens convex toward the object side, the third lens 6 is a biconcave negative lens, and the fourth lens 7 is a meniscus positive lens convex toward the image side.

[0071] The first lens group 1 further includes a fifth lens 8, and the fifth lens 8 is located on the image side of the fourth lens 7;

[0072] The second lens group 2 includes a sixth lens 9, a seventh lens 10, an eighth lens 11, and a ninth lens 12.

[0073] To improve the imaging clarity and at the same time achieve the miniaturization of the industrial lens, the industrial lens satisfies the following relational expressions:

[0074] |f u1 / f| ≤ 5.8;

[0075] |f u2 / f| ≥ 1.8;

[0076] SD max / TTL ≤ 0.36;

[0077] Wherein, f u1 is the effective focal length of the first lens group 1 in the industrial lens;

[0078] f u2 is the effective focal length of the second lens group 2 in the industrial lens;

[0079] f is the effective focal length of the industrial lens;

[0080] SD max is the clear aperture of the largest lens in the industrial lens;

[0081] TTL is the overall optical length of the industrial lens.

[0082] Reasonably distributing the proportion of the effective focal lengths f u1 、f u2 of the two lens groups to the effective focal length f of the entire lens respectively can achieve high relative illumination and high resolution of the optical system, and further improve the imaging clarity and quality.

[0083] Controlling the ratio of the clear aperture SD max of the largest lens in the industrial lens to the overall optical length TTL can achieve miniaturization of the entire lens.

[0084] In order to further improve the imaging quality, the maximum field of view angle FOV of the industrial lens and the chief ray angle CRA of the optical system formed by the industrial lens also satisfy the following relationship:

[0085] 3.3 ≤ FOV / CRA ≤ 3.6.

[0086] By the above relationship, reasonably distributing the positions of the lenses in the optical system, thereby controlling the ratio between the maximum field of view angle and the chief ray angle, can meet the requirement of low imaging distortion and further improve the imaging quality and imaging clarity.

[0087] In the embodiment of the present application, the sixth lens 9 is a biconvex positive lens, the seventh lens 10 is a biconcave negative lens, and the sixth lens 9 and the seventh lens 10 are cemented lenses.

[0088] Adopting cemented lenses for the sixth lens 9 and the seventh lens 10 can eliminate or balance the chromatic aberration and distortion generated by the lens, reduce the tolerance sensitivity, improve the imaging quality, and further enhance the imaging clarity.

[0089] Furthermore, for the Abbe number VD6 of the sixth lens 9 and the Abbe number VD7 of the seventh lens 10, the following relational expression is satisfied:

[0090] 32.8 ≤ |VD6 - VD7|;

[0091] By controlling the Abbe numbers of the sixth lens 9 and the seventh lens 10 that form the cemented lens, the chromatic aberration of the optical system can be effectively reduced, the imaging quality can be improved, and the imaging clarity can be further enhanced.

[0092] Furthermore, the refractive index Nd5 of the fifth lens 8 satisfies the following relational expression:

[0093] Nd5 ≥ 1.8.

[0094] By controlling the optical power of the fifth lens 8, specifically, by using a material with a high refractive index for the fifth lens 8, the miniaturization of the optical lens can be further achieved.

[0095] Furthermore, the refractive index Nd9 of the ninth lens 12 satisfies the following relational expression:

[0096] Nd9 ≤ 1.8;

[0097] Meanwhile, the Abbe number VD9 of the ninth lens 12 satisfies the following relational expression:

[0098] VD9 ≥ 47.9.

[0099] By controlling the Abbe number and refractive index of the ninth lens 12 and selecting a suitable combination of Abbe number and refractive index, it helps to reduce the aberration and distortion of the lens, and can ensure that the lens provides clear and accurate imaging effects under various light conditions, enhancing the imaging clarity.

[0100] In summary, it can be known that in the embodiments of the present application, an industrial lens is sequentially provided with a first lens 4, a second lens 5, a third lens 6, a fourth lens 7, a fifth lens 8, a sixth lens 9, a seventh lens 10, an eighth lens 11, and a ninth lens 12 along the optical axis from the object side to the image side.

[0101] Among them, the first lens 4 is a biconvex positive lens with a positive optical power. It has a large aperture and a large radius of curvature, which is beneficial for the industrial lens to capture light at a large angle and make it enter the rear optical system smoothly.

[0102] The second lens 5 is a meniscus positive lens convex toward the object side with a positive optical power. It can compress the light collected by the first lens 4 and reduce the diameter of the incident light, which is beneficial for controlling the volume of the lens and achieving miniaturization.

[0103] The third lens 6 is a biconcave negative lens with a negative optical power, which can diverge the light rays collected by the second lens 5, achieve the correction of light rays with different wavelengths, and is beneficial to improving the imaging quality.

[0104] The fourth lens 7 is a meniscus positive lens convex toward the image side with a positive optical power, which can focus the light rays collected by the third lens 6, is beneficial to controlling the volume of the lens, and achieving miniaturization.

[0105] The fifth lens 8 has a positive optical power, which can focus the light rays collected by the fourth lens 7, so that the light rays irradiate the target area more evenly;

[0106] At the same time, in a specific implementable manner, the optical power of the fifth lens 8 is reasonably controlled so that TTL ≤ 72.9202 mm to meet the requirements of miniaturization.

[0107] The sixth lens 9 is a biconvex positive lens with a positive optical power, and the seventh lens 10 is a biconcave negative lens with a negative optical power. The sixth lens 9 and the seventh lens 10 are cemented lenses, which can eliminate or balance the chromatic aberration and distortion generated by the lens, and reduce the tolerance sensitivity;

[0108] At the same time, both the sixth lens 9 and the seventh lens 10 are glass lenses, which can effectively improve the stability and durability of the lens.

[0109] The eighth lens 11 is a plano-convex positive lens convex toward the image side with a positive optical power, which can focus the light rays collected by the cemented lens, so that the light rays are incident on the ninth lens 12 smoothly.

[0110] The ninth lens 12 has a positive optical power, which can focus the light rays collected by the eighth lens 11 and correct the aberration, optimizing the imaging performance of the lens group;

[0111] At the same time, in this embodiment, the ninth lens 12 uses glass that is friendly to thermal drift, which can effectively improve the stability of the lens.

[0112] All the lenses of this application adopt glass materials with conventional refractive indices, effectively reducing the manufacturing cost.

[0113] In order to illustrate the above solution more clearly, the following gives three different embodiments that conform to the above solution as the specific implementation manners of this application.

[0114] Embodiment 1:

[0115] As Figure 2 shown, in Embodiment 1, the fifth lens 8 is a meniscus positive lens convex toward the object side, and the ninth lens 12 is a biconvex positive lens.

[0116] Based on the structure of the industrial lens provided above, in this embodiment, the industrial lens includes a double-convex positive lens, a meniscus positive lens convex toward the object side, a double-concave negative lens, a meniscus positive lens convex toward the image side, a meniscus positive lens convex toward the object side, a diaphragm 3, a double-convex positive lens, a double-concave negative lens, a plano-convex positive lens convex toward the image side, a double-convex positive lens, a protective glass 13, and an imaging surface 14, which are arranged coaxially in sequence.

[0117] Table 1 shows the parameters of multiple lenses in the industrial lens of Embodiment 1.

[0118] Table 1:

[0119]

[0120]

[0121] Combined Figure 1 and as Figure 2 shown, for the first lens 4, which is a double-convex positive lens, both the object side surface S1 and the image side surface S2 are convex surfaces;

[0122] For the second lens 5, which is a meniscus positive lens convex toward the object side, the object side surface S3 is convex and the image side surface S4 is concave;

[0123] For the third lens 6, which is a double-concave negative lens, both the object side surface S5 and the image side surface S6 are concave surfaces;

[0124] For the fourth lens 7, which is a meniscus positive lens convex toward the image side, the object side surface S7 is concave and the image side surface S8 is convex;

[0125] For the fifth lens 8, which is a meniscus positive lens convex toward the object side, the object side surface S9 is convex and the image side surface S10 is concave;

[0126] For the sixth lens 9, which is a double-convex positive lens, both the object side surface S12 and the image side surface S13 are convex surfaces;

[0127] For the seventh lens 10, which is a double-concave negative lens, both the object side surface S13 and the image side surface S14 are concave surfaces;

[0128] Since the sixth lens 9 and the seventh lens 10 are cemented lenses, they share S13. S13 is convex with respect to the sixth lens 9 and concave with respect to the seventh lens 10;

[0129] For the eighth lens 11, which is a plano-convex positive lens convex toward the image side, the object side surface S15 is a plane and the image side surface S16 is convex;

[0130] For the ninth lens 12, which is a double-convex positive lens, both the object side surface S17 and the image side surface S18 are convex surfaces;

[0131] S18 and S19 are the two sides of the protective glass 13.

[0132] IMA is the imaging surface 14.

[0133] In this Embodiment 1, the parameters of the industrial lens are shown in Table 2.

[0134] Table 2:

[0135] FOV 48.0000 <![CDATA[f u1 > 41.2930 <![CDATA[f u2 > 23.6917 <![CDATA[VD6]]> 60.37 <![CDATA[VD7]]> 27.55 <![CDATA[VD9]]> 47.92 f 12.2838 TTL 63.2593 CRA 14.1250 <![CDATA[SD max > 22.5723 <![CDATA[Nd5]]> 1.81 <![CDATA[Nd9]]> 1.72

[0136] As can be seen from Table 2 above, in this Embodiment 1, for the effective focal length f of the first lens group 1 in the industrial lens u1 and the effective focal length f of the entire lens, the relationship is: |f u1 / f| = 3.3616, satisfying |f u1 / f| ≤ 5.8.

[0137] For the effective focal length f of the second lens group 2 in the industrial lens u2 and the effective focal length f of the entire lens, the relationship is: |f u2 / f| = 1.9287, satisfying |f u2 / f| ≥ 1.8.

[0138] The relationship between the clear aperture SD of the largest lens max and the overall optical length TTL is: SD max / TTL = 0.3568, satisfying SD max / TTL ≤ 0.36.

[0139] The relationship between the maximum field of view FOV of the industrial lens and the chief ray angle CRA of the optical system formed by the industrial lens is: FOV / CRA = 3.3982, satisfying 3.3 ≤ FOV / CRA ≤ 3.6.

[0140] The relationship between the Abbe number VD6 of the sixth lens 9 and the Abbe number VD7 of the seventh lens 10 is: |VD6 - VD7| = 32.8208, satisfying 32.8 ≤ |VD6 - VD7|.

[0141] The refractive index Nd5 of the fifth lens 8 = 1.8052, satisfying Nd5 ≥ 1.8.

[0142] The refractive index Nd9 of the ninth lens 12 = 1.72, satisfying Nd9 ≤ 1.8.

[0143] The Abbe number VD9 of the ninth lens 12 = 47.92, satisfying VD9 ≥ 47.9.

[0144] Such as Figure 3The MTF graph of Example 1 under visible light of 450nm - 656nm is shown. The distance from the image field center to the image field edge is taken as the abscissa, and 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 picture quality has good uniformity. When it is 60lp / mm, the optical transfer function is greater than 0.7, ensuring the imaging sharpness, which reflects that this industrial lens has high resolution.

[0145] Figure 4 The field curvature / aberration graph of Example 1 is shown. The left part represents the field curvature. It can be seen from the graph that the field curvature values in the graph are all controlled within ±0.07mm, indicating that the field curvature of the industrial lens has been well corrected; the right part represents the distortion, where the abscissa represents the distortion magnitude. It can be seen from the graph that the distortion value is controlled within -1%, indicating that the distortion of the industrial lens has been well corrected and the distortion of the imaging picture has been well controlled.

[0146] Figure 5 The longitudinal aberration graph of Example 1 is shown. It can be seen from the graph that the aberration values from the shortest wavelength to the longest wavelength in the graph are all controlled within ±0.07mm, indicating that the longitudinal aberration of the industrial lens has been well corrected.

[0147] Figure 6 The lateral chromatic aberration graph of Example 1 is shown. It can be seen from the graph that the lateral chromatic aberration is small, and within the diffraction range, it has high image color reducibility.

[0148] Figure 7 The relative illumination graph of Example 1 is shown. It can be seen from the graph that the brightness change from the center to the edge is relatively uniform, so the imaging effect is good.

[0149] As Figures 3 - 7 can be seen, this industrial lens has the effects of high resolution, high relative illumination, low distortion, and low chromatic aberration, with high imaging quality and good optical performance.

[0150] Example 2:

[0151] As Figure 8 shown, in Example 2, the fifth lens 8 is a biconvex positive lens, and the ninth lens 12 is a plano-convex positive lens convex towards the object side.

[0152] Based on the structure of the industrial lens provided above, in this example, the industrial lens includes a biconvex positive lens, a meniscus positive lens convex towards the object side, a biconcave negative lens, a meniscus positive lens convex towards the image side, a biconvex positive lens, a diaphragm 3, a biconvex positive lens, a biconcave negative lens, a plano-convex positive lens convex towards the image side, a plano-convex positive lens convex towards the object side, a protective glass 13, and an imaging surface 14 arranged coaxially in sequence.

[0153] Table 3 shows the parameters of multiple lenses of the industrial lens in Embodiment 2 of the present invention.

[0154] Table 3:

[0155]

[0156]

[0157] Combined Figure 1 and as Figure 8 shown, for the first lens 4, which is a biconvex positive lens, both the object side S1 and the image side S2 are convex surfaces; for the second lens 5, which is a meniscus positive lens convex towards the object side, the object side S3 is a convex surface and the image side S4 is a concave surface;

[0158] for the third lens 6, which is a biconcave negative lens, both the object side S5 and the image side S6 are concave surfaces;

[0159] for the fourth lens 7, which is a meniscus positive lens convex towards the image side, the object side S7 is a concave surface and the image side S8 is a convex surface;

[0160] for the fifth lens 8, which is a biconvex positive lens, both the object side S9 and the image side S10 are convex surfaces;

[0161] for the sixth lens 9, which is a biconvex positive lens, both the object side S12 and the image side S13 are convex surfaces;

[0162] for the seventh lens 10, which is a biconcave negative lens, both the object side S13 and the image side S14 are concave surfaces;

[0163] Since the sixth lens 9 and the seventh lens 10 are cemented lenses, they share S13. S13 is a convex surface with respect to the sixth lens 9 and a concave surface with respect to the seventh lens 10;

[0164] for the eighth lens 11, which is a plano-convex positive lens convex towards the image side, the object side S15 is a plane and the image side S16 is a convex surface;

[0165] for the ninth lens 12, which is a plano-convex positive lens convex towards the object side, the object side S17 is a convex surface and the image side S18 is a plane;

[0166] S18 and S19 are the two sides of the protective glass 13;

[0167] IMA is the imaging surface 14.

[0168] In Embodiment 2 of the present invention, the parameters of the industrial lens are shown in Table 4.

[0169] Table 4:

[0170] FOV 48.0000 <![CDATA[f u1 > 71.1533 <![CDATA[f u2 > 22.4856 <![CDATA[VD6]]> 60.37 <![CDATA[VD7]]> 27.55 <![CDATA[VD9]]> 47.92 f 12.4055 TTL 72.9202 CRA 14.1341 <![CDATA[SD max > 22.0214 <![CDATA[Nd5]]> 1.81 <![CDATA[Nd9]]> 1.72

[0171] As can be seen from Table 4 above, in Embodiment 2 of the present invention, for the effective focal length f of the first lens group 1 in the industrial lens u1 and the relationship between the effective focal length f of the entire lens: |f u1 / f| = 5.7356, satisfying |f u1 / f| ≤ 5.8.

[0172] For the effective focal length f of the second lens group 2 in the industrial lens u2 and the relationship between the effective focal length f of the entire lens: |f u2 / f| = 1.8125, satisfying |f u2 / f| ≥ 1.8.

[0173] The relationship between the clear aperture SD of the largest lens and the overall optical length TTL: SD max / TTL = 0.3020, satisfying SD max / TTL ≤ 0.36. max / TTL ≤ 0.36.

[0174] The relationship between the maximum field of view FOV of the industrial lens and the chief ray angle CRA of the optical system formed by the industrial lens: FOV / CRA = 3.3960, satisfying 3.3 ≤ FOV / CRA ≤ 3.6.

[0175] The relationship between the Abbe number VD6 of the sixth lens 9 and the Abbe number VD7 of the seventh lens 10: |VD6 - VD7| = 32.8208, satisfying 32.8 ≤ |VD6 - VD7|.

[0176] The refractive index Nd5 of the fifth lens 8 = 1.8052, satisfying Nd5 ≥ 1.8.

[0177] The refractive index Nd9 of the ninth lens 12 = 1.72, satisfying Nd9 ≤ 1.8.

[0178] The Abbe number VD9 of the ninth lens 12 = 47.92, satisfying VD9 ≥ 47.9.

[0179] As Figure 9 shown is the MTF graph of this embodiment under visible light of 450nm - 656nm. Taking the distance from the image field center to the image field edge as the abscissa, 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 picture quality has good uniformity, and at 60 lp / mm, the optical transfer function is greater than 0.7, ensuring the imaging clarity, reflecting that this industrial lens has a high resolution.

[0180] Figure 10This 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 in the figure are all controlled within ±0.05 mm, indicating that the field curvature of the industrial lens has been well corrected. The right part represents the distortion, where the abscissa represents the distortion magnitude. As can be seen from the figure, the distortion value is controlled within -3%, indicating that the distortion of the industrial lens has been well corrected and the distortion of the imaging picture has been well controlled.

[0181] Figure 11 This is the longitudinal aberration diagram of this embodiment. As can be seen from the figure, the aberration values from the shortest wavelength to the longest wavelength in the figure are all controlled within ±0.05 mm, indicating that the longitudinal aberration of the industrial lens has been well corrected.

[0182] Figure 12 This is the lateral chromatic aberration diagram of this embodiment. As can be seen from the figure, the lateral chromatic aberration is small and has high image color reducibility within the diffraction range.

[0183] Figure 13 This is the relative illumination diagram of this embodiment. As can be seen from the figure, when the field of view angle in the Y direction is within 16.9, the relative illumination is greater than 90%, so the imaging effect is good.

[0184] From Figures 9 - 13 It can be seen that this industrial lens has the effects of high resolution, high relative illumination, low distortion, and low chromatic aberration, with high imaging quality and good optical performance.

[0185] Embodiment 3:

[0186] As Figure 14 shown, in Embodiment 3, the fifth lens 8 is a biconvex positive lens, the eighth lens 11 is a plano-convex positive lens convex toward the image side, and the ninth lens 12 is a meniscus positive lens convex toward the object side.

[0187] Based on the structure of the industrial lens provided above, in this embodiment, the industrial lens includes a biconvex positive lens, a meniscus positive lens convex toward the object side, a biconcave negative lens, a meniscus positive lens convex toward the image side, a biconvex positive lens, a diaphragm 3, a biconvex positive lens, a biconcave negative lens, a plano-convex positive lens convex toward the image side, a meniscus positive lens convex toward the object side, a protective glass 13, and an imaging surface 14 arranged coaxially in sequence.

[0188] Table 5 shows the parameters of multiple lenses of the industrial lens in this Embodiment 3.

[0189] Table 5:

[0190]

[0191]

[0192] Combined with Figure 1Heru Figure 14 As shown in Figure 14 , both the object side S1 and the image side S2 of the first lens 4, which is a biconvex positive lens, are convex surfaces;

[0193] For the second lens 5, which is a meniscus positive lens convex toward the object side, the object side S3 is a convex surface and the image side S4 is a concave surface;

[0194] For the third lens 6, which is a biconcave negative lens, both the object side S5 and the image side S6 are concave surfaces;

[0195] For the fourth lens 7, which is a meniscus positive lens convex toward the image side, the object side S7 is a concave surface and the image side S8 is a convex surface;

[0196] For the fifth lens 8, which is a biconvex positive lens, both the object side S9 and the image side S10 are convex surfaces;

[0197] For the sixth lens 9, which is a biconvex positive lens, both the object side S12 and the image side S13 are convex surfaces;

[0198] For the seventh lens 10, which is a biconcave negative lens, both the object side S13 and the image side S14 are concave surfaces;

[0199] Since the sixth lens 9 and the seventh lens 10 are cemented lenses, they share S13. S13 is a convex surface with respect to the sixth lens 9 and a concave surface with respect to the seventh lens 10;

[0200] For the eighth lens 11, which is a plano-convex positive lens convex toward the image side, the object side S15 is a plane and the image side S16 is a convex surface;

[0201] For the ninth lens 12, which is a meniscus positive lens convex toward the object side, the object side S17 is a convex surface and the image side S18 is a concave surface;

[0202] S18 and S19 are the two sides of the protective glass 13;

[0203] IMA is the imaging surface 14.

[0204] In this Embodiment 3, the parameters of the industrial lens are shown in Table 6.

[0205] Table 6:

[0206]

[0207]

[0208] As can be seen from the above Table 6, in this Embodiment 3, the relationship between the effective focal length f u1 of the first lens group 1 in the industrial lens and the effective focal length f of the entire lens is: |f u1 / f| = 5.2198, which satisfies |f u1 / f| ≤ 5.8.

[0209] The relationship between the effective focal length f of the second lens group 2 in the industrial lens and the effective focal length f of the entire lens: |f u2 / f| = 1.8524, satisfying |f u2 / f| ≥ 1.8. u2 / f|≥1.8

[0210] The relationship between the clear aperture SD of the largest lens and the overall optical length TTL: SD max / TTL = 0.3262, satisfying SD max / TTL ≤ 0.36. max / TTL≤0.36

[0211] The relationship between the maximum field of view FOV of the industrial lens and the chief ray angle CRA of the optical system formed by the industrial lens: FOV / CRA = 3.5935, satisfying 3.3 ≤ FOV / CRA ≤ 3.6.

[0212] The relationship between the Abbe number VD6 of the sixth lens 9 and the Abbe number VD7 of the seventh lens 10: |VD6 - VD7| = 32.8208, satisfying 32.8 ≤ |VD6 - VD7|.

[0213] The refractive index Nd5 of the fifth lens 8 = 1.8052, satisfying Nd5 ≥ 1.8.

[0214] The refractive index Nd9 of the ninth lens 12 = 1.72, satisfying Nd9 ≤ 1.8.

[0215] The Abbe number VD9 of the ninth lens 12 = 47.92, satisfying VD9 ≥ 47.9.

[0216] As Figure 15 shown is the MTF graph of this embodiment under visible light of 450nm - 656nm. With the distance from the image field center to the image field edge as the abscissa, 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 picture quality has good uniformity. At 60 lp / mm, the optical transfer function is greater than 0.7, ensuring the imaging clarity, reflecting that this industrial lens has high resolution.

[0217] Figure 16 Shown is the field curvature / distortion graph of this embodiment. The left part represents the field curvature. From the graph, it can be seen that the field curvature values in the graph are all controlled within ±0.07 mm, indicating that the field curvature of the industrial lens has been well corrected; the right part represents the distortion, where the abscissa represents the distortion magnitude. From the graph, it can be seen that the distortion value is controlled within -2%, indicating that the distortion of the industrial lens has been well corrected and the distortion of the imaging picture has been well controlled.

[0218] Figure 17This is the longitudinal aberration diagram of this embodiment. As can be seen from the figure, the aberration values from the shortest wavelength to the longest wavelength in the figure are all controlled within ±0.07 mm, indicating that the longitudinal aberration of the industrial lens has been well corrected.

[0219] Figure 18 This is the lateral chromatic aberration diagram of this embodiment. As can be seen from the figure, the lateral chromatic aberration is small, and within the diffraction range, it has high image color reducibility.

[0220] Figure 19 This is the relative illumination diagram of this embodiment. As can be seen from the figure, the brightness change from the center to the edge is relatively uniform, so the imaging effect is good.

[0221] It can be seen from Figures 15 - 19 that this industrial lens has the effects of high resolution, high relative illumination, low distortion, and low chromatic aberration, with high imaging quality and good optical performance.

[0222] The above are only optional embodiments of this application, and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. An industrial lens, characterized in that: It includes a first lens group (1) and a second lens group (2) which are coaxially arranged in sequence from the object side to the image side, and a diaphragm (3) is arranged between the first lens group (1) and the second lens group (2); The first lens group (1) includes a pre - order lens group, and the pre - order lens group includes a first lens (4), a second lens (5), a third lens (6) and a fourth lens (7) arranged in sequence from the object side to the image side. The first lens (4) of the pre - order lens group is a biconvex positive lens, the second lens (5) is a meniscus positive lens convex towards the object side, the third lens (6) is a biconcave negative lens, and the fourth lens (7) is a meniscus positive lens convex towards the image side; The first lens group (1) further includes a fifth lens (8), and the fifth lens (8) is located on the image side of the fourth lens (7), and the fifth lens (8) is a positive lens; The second lens group (2) includes a sixth lens (9), a seventh lens (10), an eighth lens (11) and a ninth lens (12). The sixth lens (9) is a biconvex positive lens, the seventh lens (10) is a biconcave negative lens, and the sixth lens (9) and the seventh lens (10) are cemented lenses; This industrial lens satisfies the following relational expressions, |f u1 / f| ≤ 5.8; |f u2 / f| ≥ 1.8; SD max / TTL ≤ 0.36; where f u1 is the effective focal length of the first lens group (1) in the industrial lens, f u2 is the effective focal length of the second lens group (2) in the industrial lens, f is the effective focal length of the industrial lens, SD max is the clear aperture of the largest lens in the industrial lens, and TTL is the overall optical length of the industrial lens.

2. The industrial lens according to claim 1, wherein: This industrial lens also satisfies the following relational expressions, 3.3 ≤ FOV / CRA ≤ 3.6; Wherein, FOV is the maximum field of view angle of this industrial lens, and CRA is the chief ray angle of the optical system formed by this industrial lens.

3. An industrial lens according to claim 1, characterized in that: This industrial lens satisfies the following relational expressions, 32.8 ≤ |VD6 - VD7|; Wherein, VD6 is the Abbe number of the sixth lens (9), and VD7 is the Abbe number of the seventh lens (10).

4. An industrial lens according to claim 1, characterized in that: This industrial lens satisfies the following relational expressions, Nd5 ≥ 1.8; Wherein, Nd5 is the refractive index of the fifth lens (8).

5. An industrial lens according to claim 1, characterized in that: This industrial lens satisfies the following relational expressions, Nd9 ≤ 1.8; VD9 ≥ 47.9; Wherein, Nd9 is the refractive index of the ninth lens (12), and VD9 is the Abbe number of the ninth lens (12).

6. An industrial lens according to claim 1, characterized in that: The fifth lens (8) is a meniscus positive lens convex towards the object side, the eighth lens (11) is a plano - convex positive lens convex towards the image side, and the ninth lens (12) is a biconvex positive lens.

7. An industrial lens according to claim 1, characterized in that: The fifth lens (8) is a biconvex positive lens, the eighth lens (11) is a plano - convex positive lens convex towards the image side, and the ninth lens (12) is a plano - convex positive lens convex towards the object side.

8. An industrial lens according to claim 1, characterized in that: The fifth lens (8) is a biconvex positive lens, the eighth lens (11) is a plano - convex positive lens convex towards the image side, and the ninth lens (12) is a meniscus positive lens convex towards the object side.

Images