Industrial lens

Abstract

The invention discloses an industrial lens, and belongs to the field of optical lenses. An industrial lens comprises a first lens group and a second lens group which are coaxially arranged, a diaphragm is arranged between the first lens group and the second lens group, the first lens group comprises a first lens, a second lens and a third lens which are sequentially arranged from an object space to an image space, the first lens and the second lens have positive focal power, and the third lens has negative focal power; the second lens group comprises a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from the object space to the image space, the fourth lens and the seventh lens have negative focal power, and the fifth lens and the sixth lens have positive focal power; the industrial lens satisfies the following relational expression: IH / FNO is greater than or equal to 3.12; fu1 / f is less than or equal to 2.1; fu2 / f is greater than or equal to 0.65; fOV / (D * TTL) > = 0.03; wherein IH is the maximum image plane height of the industrial lens, FNO is the aperture value of the industrial lens, fu1 is the effective focal length of a first lens group in the industrial lens, fu2 is the effective focal length of a second lens group in the industrial lens, f is the effective focal length of the whole industrial lens, FOV is the maximum field angle of the industrial lens, D is the head aperture size of the industrial lens, and TTL is the total optical length of the industrial lens. The industrial lens provided by the invention has the advantages of wide visual field, high resolution and compact size, and is of great significance in promoting the technical progress in the field of industrial automation.

Description

Technical Field

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

[0002] Industrial lenses are a vital component in the field of industrial automation. They play a core role in machine vision, quality inspection, and automated production lines, and their main task is to capture image information. These industrial lenses can be regarded as the "visual organs" of the machine, and their performance directly affects the efficiency and accuracy of the entire visual system. However, traditional industrial lenses often show certain limitations when facing the complex demands of modern industrial environments.

[0003] Specifically, given the special needs of industrial environments, industrial lenses usually need to meet higher technical specifications than general lenses. For example, modern industrial production lines often need to be monitored within a larger field of view to ensure full coverage of the production process; at the same time, higher requirements are also placed on image contrast to ensure that the machine vision system can accurately identify and process various details. In addition, with the development trend of equipment miniaturization, industrial lenses also need to have a more compact size to adapt to limited space layouts.

[0004] Although there are many industrial lens products on the market, not many can meet the above high standards at the same time. Therefore, developing a new industrial lens with a wide field of view, high resolution and compact size is of great significance to promoting technological progress in the field of industrial automation. Summary of the invention

[0005] In order to meet market demand and improve the overall performance of industrial automation systems, this application provides an industrialized lens.

[0006] The industrial lens provided in this application adopts the following technical solution: An industrial lens, comprising a first lens group and a second lens group arranged coaxially, an aperture is arranged between the first lens group and the second lens group, the first lens group comprises a first lens, a second lens and a third lens arranged in sequence from the object side to the image side, the first lens and the second lens have positive focal power, and the third lens has negative focal power; The second lens group includes a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence from the object side to the image side, the fourth lens and the seventh lens have negative optical power, and the fifth lens and the sixth lens have positive optical power; the industrial lens satisfies the following relationship: IH / FNO≥3.12; |f u1 / f|≤2.1; |f u2 / f|≥0.65; FOV / (D*TTL)≥0.03; Wherein, IH is the maximum image plane height of the industrial lens, FNO is the aperture value of the industrial lens, and 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 entire industrial lens, FOV is the maximum field of view of the industrial lens, D is the head aperture size of the industrial lens, and TTL is the total optical length of the industrial lens.

[0007] By adopting the above technical solution, the ratio between the maximum image plane height and the aperture value of the industrial lens is controlled, thereby meeting the demand for large target surface imaging of the industrial lens; at the same time, the industrial lens is divided into two lens groups, and the demand for high resolution of the industrial lens is met by reasonably allocating the proportion of the optical power of the two lens groups and the entire industrial lens optical power. The above solution enables the industrial lens to maintain the compactness of its own structure while meeting the requirements of large target surface imaging and high resolution, which is more conducive to the use of industrial lenses in industrial production lines.

[0008] Preferably, the industrial lens also satisfies the following relationship: 0.8≤|f u1 / f u2 |≤2.8.

[0009] By adopting the above technical solution, the optical focal length of the two lens groups is reasonably allocated and the ratio relationship between the two is controlled, so as to meet the demand for clear imaging of large target surfaces of industrial lenses.

[0010] 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.

[0011] By adopting the above technical solution, the second lens and the third lens are made into a cemented part, which can effectively improve the relative brightness and reduce the tolerance sensitivity.

[0012] 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.

[0013] By adopting the above technical solution, the fourth lens and the fifth lens are made into a cemented part, which can effectively improve the relative brightness and reduce the tolerance sensitivity.

[0014] Preferably, the industrial lens also satisfies the following relationship: 0.05≤(f G1 / (f G2 *f))*tan(FOV / 3)≤0.08; Among them, is the effective focal length of the first cemented lens group in the industrial lens, and is the effective focal length of the second cemented lens group in the industrial lens.

[0015] By adopting the above technical solution, the optical power of the two groups of cemented lenses is reasonably distributed, thereby meeting the demand for high relative brightness of industrial lenses and reducing the assembly sensitivity of industrial lenses.

[0016] Preferably, the second lens, the third lens, the fourth lens and the fifth lens are all glass lenses.

[0017] By adopting the above technical solution, the second lens, the third lens, the fourth lens and the fifth lens are all glass lenses, which can effectively improve the stability and durability of the lens group.

[0018] Preferably, the first lens is a meniscus positive lens convex toward the object side, the second lens is a double convex positive lens, the third lens is a double concave negative lens, the fourth lens is a double concave negative lens, the fifth lens is a double convex positive lens, the sixth lens is a double convex positive lens, and the seventh lens is a meniscus negative lens convex toward the image side.

[0019] Preferably, the first lens is a meniscus positive lens convex toward the object side, the second lens is a biconvex positive lens, the third lens is a biconcave negative lens, the fourth lens is a biconcave negative lens, the fifth lens is a biconvex positive lens, the sixth lens is a biconvex positive lens, and the seventh lens is a biconcave negative lens.

[0020] Preferably, the first lens is a biconvex positive lens, the second lens is a biconvex positive lens, the third lens is a biconcave negative lens, the fourth lens is a biconcave negative lens, the fifth lens is a biconvex positive lens, the sixth lens is a biconvex positive lens, and the seventh lens is a meniscus negative lens convex toward the image side.

[0021] By adopting the above technical solution, three feasible lens shape combinations of each lens in the industrial lens are given, which provides a basis for the specific implementation of this solution.

[0022] In summary, this application has at least the following beneficial effects: (1) The present application controls the ratio between the maximum image plane height and the aperture value of the industrial lens, thereby expanding the imaging target surface; at the same time, the industrial lens is divided into two lens groups, and the optical power of the two lens groups is reasonably allocated to the proportion of the optical power of the entire industrial lens, thereby achieving the high resolution requirement of the industrial lens while maintaining the optical performance.

[0023] (2) The present application optimizes the optical performance by introducing two groups of cemented lenses in the lens design, and reasonably distributes the optical focal length of the two groups of cemented lenses, thereby improving the relative brightness and helping to achieve miniaturization of the lens.

[0024] (3) The present application can maintain image clarity over a wider field of view by precisely controlling the distribution of optical power between the two lens groups, thereby meeting the need for clear imaging of large target surfaces of industrial lenses, and enabling the lenses to more accurately capture and identify in industrial environments, thereby functioning efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a lens layout diagram of an embodiment of the present application; Figure 2 is the optical path diagram of Example 1 of the present application; Figure 3 This is the MTF curve of Example 1 of the present application under visible light 486nm-656nm; Figure 4 is a relative illumination diagram of Example 1 of the present application under visible light 588nm; Figure 5 is the optical path diagram of Example 2 of the present application; Figure 6 This is the MTF curve diagram of Example 2 of the present application under visible light 486nm-656nm; Figure 7 is a relative illumination diagram of Example 2 of the present application under visible light 588nm; Figure 8 is a light path diagram of Example 3 of the present application; Fig. 9 This is the MTF curve diagram of Example 3 of the present application under visible light 486nm-656nm; Fig.10 This is a relative illumination diagram of Example 3 of the present application under visible light of 588 nm.

[0026] Description of reference numerals: 1. First lens group; 2. Second lens group; 3. Aperture; 4. First lens; 5. Second lens; 6. Third lens; 7. Fourth lens; 8. Fifth lens; 9. Sixth lens; 10. Seventh lens; 11. Imaging surface; 12. Protective glass. DETAILED DESCRIPTION

[0027] The present application provides an industrial lens. To make the purpose, technical solution and advantages of the present application clearer, the implementation method of the present application will be further described in detail below.

[0028] 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.

[0029] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0030] The present application proposes an industrial lens, comprising a first lens group 1, a stop 3 (ie, STO) and a second lens group 2 which are coaxially arranged.

[0031] In an embodiment of the present application, two front and rear lens groups are arranged in the direction from the object side to the image side. The front lens group is close to the object side, which is the first lens group 1, and the rear lens group is close to the image side, which is the second lens group 2.

[0032] An aperture 3 is arranged between the first lens group 1 and the second lens group 2. The aperture 3 controls the imaging quality and the performance of the optical system by limiting the propagation range and direction of the light beam.

[0033] The first lens group 1 includes a first lens 4, a second lens 5 and a third lens 6 which are arranged in sequence from the object side to the image side. The first lens 4 and the second lens 5 have positive optical power, and the third lens 6 has negative optical power.

[0034] The second lens group 2 includes a fourth lens 7, a fifth lens 8, a sixth lens 9 and a seventh lens 10 which are arranged in sequence from the object side to the image side. The fourth lens 7 and the seventh lens 10 have negative optical power, and the fifth lens 8 and the sixth lens 9 have positive optical power.

[0035] Industrial lenses satisfy the following relationship: IH / FNO≥3.12; |f u1 / f|≤2.1; |f u2 / f|≥0.65; FOV / (D*TTL)≥0.03; Where IH is the maximum image height of the industrial lens; FNO is the aperture value of the industrial lens; 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 entire industrial lens; FOV: the maximum field of view of an industrial lens; D is the head aperture size of the industrial lens; TTL is the total optical length of the industrial lens, that is, the distance from the center of the object side of the first lens 4 to the imaging surface 11.

[0036] In the embodiments of the present application, the relationship between the maximum image plane height IH and the aperture value FNO of the industrial lens is reasonably allocated, so that a large target surface can be imaged. The proportion of the optical power of the front and rear lens groups to the optical power f of the entire lens is reasonably allocated, so that the high resolution of the lens can be achieved. Furthermore, controlling the relationship between the maximum field of view FOV, aperture size D and total optical length TTL of the industrial lens can make the structure of the entire industrial lens more compact, thereby realizing the miniaturization of the industrial lens and making it more convenient to use on industrial production lines.

[0037] In the embodiment of the present application, the second lens 5 is a biconvex positive lens, the third lens 6 is a biconcave negative lens, and the second lens 5 and the third lens 6 form a first cemented lens group.

[0038] The fourth lens 7 is a double concave negative lens, the fifth lens 8 is a double convex positive lens, and the fourth lens 7 and the fifth lens 8 form a second cemented lens group.

[0039] The second lens 5 and the third lens 6 form a cemented part, and the fourth lens and the fifth lens form a cemented part, which can effectively improve the relative brightness and reduce the tolerance sensitivity.

[0040] In the embodiment of the present application, the effective focal length f of the first cemented lens group is G1 , the effective focal length f of the second cemented lens group G2 The following relationship is also satisfied between the effective focal length f of the industrial lens and the maximum field of view FOV: 0.05≤(f G1 / (f G2 *f))*tan(FOV / 3)≤0.08.

[0041] By properly distributing the optical power of two sets of cemented lenses, the demand for high relative brightness of industrial lenses can be met while reducing the assembly sensitivity of industrial lenses.

[0042] At the same time, the second lens 5, the third lens 6, the fourth lens 7 and the fifth lens 8 in the embodiment of the present application are all glass lenses, which can effectively improve the stability and durability of the lens group.

[0043] Through the above solution, it is possible to achieve large-scale imaging while ensuring high resolution and relative illumination of the lens. Both high resolution and relative illumination can improve the clarity of industrial lenses.

[0044] In order to further ensure the high definition requirements of industrial lenses, the effective focal length f of the first lens group 1 isu1 and the effective focal length f of the second lens group 2 u2 The following relationship is also satisfied: 0.8≤|f u1 / f u2 |≤2.8; By using the above formula, the optical focal length of the two lens groups can be reasonably allocated and the ratio between the two can be controlled, which can further improve the clarity of large target surface imaging.

[0045] In an embodiment of the present application, the industrial lens is provided with a first lens 4, a second lens 5, a third lens 6, an aperture 3, a fourth lens 7, a fifth lens 8, a sixth lens 9, a seventh lens 10, a protective glass 12 and an imaging surface 11 in sequence along the optical axis from the object side to the image side.

[0046] The first lens 4 has positive optical power, and its curved shape is conducive to the lens acquiring light at a large angle.

[0047] The second lens 5 has positive optical power and is a biconvex positive lens, and the third lens 6 has negative optical power and is a biconcave negative lens. The second lens 5 and the third lens 6 are glued together to effectively improve relative brightness and reduce tolerance sensitivity.

[0048] The aperture 3 controls the imaging quality by limiting the propagation range and direction of the light beam.

[0049] The fourth lens 7 has negative optical power and is a double concave negative lens. The fifth lens 8 has positive optical power and is a double convex positive lens. The fourth lens 7 and the fifth lens 8 are glued together to effectively improve relative brightness and reduce tolerance sensitivity.

[0050] Meanwhile, in a specific implementable manner, the fourth lens 7 controls the optical focal length so that the total optical length TTL is ≤ 42 mm, so as to meet the requirement of miniaturization of the lens.

[0051] The sixth lens 9 has positive optical power and is a double convex positive lens. It focuses the light collected by the fifth lens 8 and corrects the aberration to optimize the imaging performance of the lens group.

[0052] The seventh lens 10 has negative optical power and is used to focus the light collected by the sixth lens 9, which is beneficial to the field correction of the lens and optimizes the imaging performance of the lens group.

[0053] In order to explain the above scheme more clearly, three different embodiments that conform to the above scheme are given below:.

[0054] Embodiment 1: like Figure 2As shown, in Example 1, the first lens 4 is a meniscus positive lens convex to the object side, the second lens 5 is a double convex positive lens, the third lens 6 is a double concave negative lens, the fourth lens 7 is a double concave negative lens, the fifth lens 8 is a double convex positive lens, the sixth lens 9 is a double convex positive lens, and the seventh lens 10 is a meniscus negative lens convex to the image side.

[0055] Based on the structure of the industrial lens provided above, the industrial lens includes a meniscus positive lens convex toward the object side, a double convex positive lens, a double concave negative lens, an aperture 3, a double concave negative lens, a double convex positive lens, a double convex positive lens, a meniscus negative lens convex toward the image side, a protective glass 12 and an imaging surface 11, which are coaxially arranged in sequence.

[0056] Table 1 shows various parameters of multiple lenses of the industrial lens in this embodiment 1.

[0057] Table 1: Combination Figure 1 and Figure 2 As shown, the object side surface S1 of the first lens 4, i.e., the positive meniscus lens convex toward the object side, is a convex surface, and the image side surface S2 is a concave surface; The object side surface S3 of the second lens 5, i.e., the biconvex positive lens, is convex, and the image side surface S4 is convex; The object side surface S4 of the third lens element 6, i.e., the double concave negative lens, is concave, and the image side surface S5 is concave; The second lens 5 and the third lens 6 are cemented together and share S4, so S4 is convex relative to the second lens 5 and concave relative to the third lens 6.

[0058] The fourth lens element 7, i.e., a double concave negative lens, has an object side surface S7 which is a concave surface, and an image side surface S8 which is a concave surface; The object side surface S8 of the fifth lens element 8, i.e., the biconvex positive lens, is convex, and the image side surface S9 is convex; The fourth lens 7 and the fifth lens 8 are cemented together and share S8, so S8 is concave relative to the fourth lens 7 and is convex relative to the fifth lens 8.

[0059] The object side surface S10 of the sixth lens element 9, i.e., the biconvex positive lens, is a convex surface, and the image side surface S11 is a convex surface; The seventh lens element 10, i.e., a negative meniscus lens convex toward the image side, has an object side surface S12 that is concave, and an image side surface S13 that is convex; S14 and S15 are two sides of the protective glass 12; IMA is an imaging surface 11 .

[0060] In this embodiment 1, the parameters of the industrial lens are shown in Table 2.

[0061] Table 2: FOV 25.0000 <![CDATA[f G1 ]]> -46.2543 <![CDATA[f G2 ]]> 52.0771 <![CDATA[f u1 ]]> 50.1620 <![CDATA[f u2 ]]> 19.0905 f 25.0178 D 19.4521 TTL 39.9356 IH 5.6150 FNO 1.7788 It can be seen from Table 2 above that in this embodiment 1, the relationship between the maximum image plane height IH and the aperture value FNO of the industrial lens is: IH / FNO=3.1566, satisfying IH / FNO≥3.12; The effective focal length f of the first lens group 1 u1 The relationship between the effective focal length f of the entire industrial lens: |f u1 / f|=2.0051, satisfying |f u1 / f|≤2.1; The effective focal length f of the second lens group 2 u2 The relationship between the effective focal length f of the entire industrial lens: |f u2 / f|=0.7631, satisfying |f u2 / f|≥0.65; The relationship between the maximum field of view FOV of the industrial lens, the head aperture size D and the total optical length TTL is: FOV / (D*TTL)=0.0322, satisfying FOV / (D*TTL)≥0.03; The effective focal length f of the first cemented lens group G1 , the effective focal length f of the second cemented lens group G2 , the effective focal length f of the industrial lens and the maximum field of view FOV: G1 / (f G2 *f))*tan(FOV / 3)=0.0683, satisfying 0.05≤(f G1 / (f G2 *f))*tan(FOV / 3)≤0.08; The effective focal length f of the first lens group 1 u1 and the effective focal length f of the second lens group 2 u2 The relationship between: |f u1 / f u2 |=2.6276, satisfying 0.8≤|f u1 / f u2 |≤2.8; and Figure 2 The total optical length TTL of the industrial lens is 39.93555mm, satisfying TTL≤42mm.

[0062] like Figure 3 The MTF diagram of Example 1 is shown. The horizontal axis is the distance from the center of the image field to the edge of the image field. It can be seen from the figure that at 60lp / mm, the optical transfer function is greater than 0.6, and the clarity of the image is guaranteed, reflecting that the industrial lens has a high resolution.

[0063] Figure 4This is a relative illumination diagram of the present embodiment 1. It can be seen from the diagram that the relative brightness of the edge field of view is greater than 60%, so the imaging effect is good.

[0064] Depend on Figure 3 and Figure 4 It can be seen that the industrial lens of this embodiment has the effects of high resolution and high relative illumination, improves the clarity of imaging, has high imaging quality and good optical performance.

[0065] Embodiment 2: like Figure 5 As shown, in Example 2, the first lens 4 is a meniscus positive lens convex toward the object side, the second lens 5 is a double convex positive lens, the third lens 6 is a double concave negative lens, the fourth lens 7 is a double concave negative lens, the fifth lens 8 is a double convex positive lens, the sixth lens 9 is a double convex positive lens, and the seventh lens 10 is a double concave negative lens.

[0066] Based on the structure of the industrial lens provided above, the industrial lens includes a meniscus positive lens convex toward the object, a double convex positive lens, a double concave negative lens, an aperture 3, a double concave negative lens, a double convex positive lens, a double convex positive lens, a double concave negative lens, a protective glass 12 and an imaging surface 11 arranged coaxially in sequence.

[0067] Table 3 shows various parameters of multiple lenses of the industrial lens in this embodiment 2.

[0068] Table 3: like Figure 1 and Figure 5 As shown, the object side surface S1 of the first lens 4, i.e., the positive meniscus lens convex toward the object side, is a convex surface, and the image side surface S2 is a concave surface; The object side surface S3 of the second lens 5, i.e., the biconvex positive lens, is convex, and the image side surface S4 is convex; The object side surface S4 of the third lens element 6, i.e., the double concave negative lens, is concave, and the image side surface S5 is concave; The second lens 5 and the third lens 6 are cemented together and share S4, so S4 is convex relative to the second lens 5 and concave relative to the third lens 6.

[0069] The fourth lens element 7, i.e., a double concave negative lens, has an object side surface S7 which is a concave surface, and an image side surface S8 which is a concave surface; The object side surface S8 of the fifth lens element 8, i.e., the biconvex positive lens, is convex, and the image side surface S9 is convex; The fourth lens 7 and the fifth lens 8 are cemented together and share S8, so S8 is concave relative to the fourth lens 7 and is convex relative to the fifth lens 8.

[0070] The object side surface S10 of the sixth lens element 9, i.e., the biconvex positive lens, is a convex surface, and the image side surface S11 is a convex surface; The object side surface S12 of the seventh lens element 10, i.e., the double concave negative lens, is a concave surface, and the image side surface S13 is a concave surface; S14 and S15 are two sides of the protective glass 12; IMA is an imaging surface 11 .

[0071] In this embodiment 2, the parameters of the industrial lens are shown in Table 4.

[0072] Table 4: It can be seen from Table 4 above that in this embodiment 2, the relationship between the maximum image plane height IH and the aperture value FNO of the industrial lens is: IH / FNO=3.2847, satisfying IH / FNO≥3.12; The effective focal length f of the first lens group 1 u1 The relationship between the effective focal length f of the entire industrial lens: |f u1 / f|=2.0858, satisfying |f u1 / f|≤2.1; The effective focal length f of the second lens group 2 u2 The relationship between the effective focal length f of the entire industrial lens: |f u2 / f|=0.7681, satisfying |f u2 / f|≥0.65; The relationship between the maximum field of view FOV of the industrial lens, the head aperture size D and the total optical length TTL is: FOV / (D*TTL)=0.0354, satisfying FOV / (D*TTL)≥0.03; The effective focal length f of the first cemented lens group G1 , the effective focal length f of the second cemented lens group G2 , the effective focal length f of the industrial lens and the maximum field of view FOV: G1 / (f G2 *f))*tan(FOV / 3)=0.0552, satisfying 0.05≤(f G1 / (f G2 *f))*tan(FOV / 3)≤0.08; The effective focal length f of the first lens group 1 u1 and the effective focal length f of the second lens group 2 u2 The relationship between: |f u1 / f u2 |=2.7155, satisfying 0.8≤|f u1 / f u2 |≤2.8; and Figure 5The total optical length TTL of the industrial lens is 41.65514mm, satisfying TTL≤42mm.

[0073] like Figure 6 The MTF diagram of Example 2 is shown, and the horizontal axis is the distance from the center of the image field to the edge of the image field. It can be seen from the figure that at 60lp / mm, the optical transfer function is greater than 0.7, and the clarity of the image is guaranteed, reflecting that this industrial lens has a high resolution.

[0074] Figure 7 This is a relative illumination diagram of the second embodiment. It can be seen from the diagram that the relative brightness of the edge field of view is greater than 70%, so the imaging effect is good.

[0075] Depend on Figure 6 and Figure 7 It can be seen that the industrial lens of this embodiment has the effects of high resolution and high relative illumination, improves the clarity of imaging, has high imaging quality and good optical performance.

[0076] Embodiment 3: like Figure 8 As shown, in Example 3, the first lens 4 is a biconvex positive lens, the second lens 5 is a biconvex positive lens, the third lens 6 is a biconcave negative lens, the fourth lens 7 is a biconcave negative lens, the fifth lens 8 is a biconvex positive lens, the sixth lens 9 is a biconvex positive lens, and the seventh lens 10 is a meniscus negative lens convex toward the image side.

[0077] 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 3, a biconcave negative lens, a biconvex positive lens, a biconvex positive lens, a meniscus negative lens convex toward the image side, an imaging surface 11 and a protective glass 12 arranged coaxially in sequence.

[0078] Table 5 shows various parameters of multiple lenses of the industrial lens in this embodiment 3.

[0079] Table 5: Combination Figure 1 and Figure 8 As shown, the object side surface S1 of the first lens 4, i.e., the biconvex positive lens, is a convex surface, and the image side surface S2 is a convex surface; The object side surface S3 of the second lens 5, i.e., the biconvex positive lens, is convex, and the image side surface S4 is convex; The object side surface S4 of the third lens element 6, i.e., the double concave negative lens, is concave, and the image side surface S5 is concave; The second lens 5 and the third lens 6 are cemented together and share S4, so S4 is convex relative to the second lens 5 and concave relative to the third lens 6.

[0080] The fourth lens element 7, i.e., a double concave negative lens, has an object side surface S7 which is a concave surface, and an image side surface S8 which is a concave surface; The object side surface S8 of the fifth lens element 8, i.e., the biconvex positive lens, is convex, and the image side surface S9 is convex; The fourth lens 7 and the fifth lens 8 are cemented together and share S8, so S8 is concave relative to the fourth lens 7 and is convex relative to the fifth lens 8.

[0081] The object side surface S10 of the sixth lens element 9, i.e., the biconvex positive lens, is a convex surface, and the image side surface S11 is a convex surface; The seventh lens element 10, i.e., a negative meniscus lens convex toward the image side, has an object side surface S12 that is concave, and an image side surface S13 that is convex; S14 and S15 are two sides of the protective glass 12; IMA is an imaging surface 11 .

[0082] In this embodiment 3, the parameters of the industrial lens are shown in Table 6.

[0083] Table 6: It can be seen from Table 6 above that in this embodiment 3, the relationship between the maximum image plane height IH and the aperture value FNO of the industrial lens is: IH / FNO=3.1324, satisfying IH / FNO≥3.12; The effective focal length f of the first lens group 1 u1 The relationship between the effective focal length f of the entire industrial lens: |f u1 / f|=0.5383, satisfying |f u1 / f|≤2.1; The effective focal length f of the second lens group 2 u2 The relationship between the effective focal length f of the entire industrial lens: |f u2 / f|=0.6578, satisfying |f u2 / f|≥0.65; The relationship between the maximum field of view FOV of the industrial lens, the head aperture size D and the total optical length TTL is: FOV / (D*TTL)=0.0352, satisfying FOV / (D*TTL)≥0.03; The effective focal length f of the first cemented lens group G1 , the effective focal length f of the second cemented lens group G2 , the effective focal length f of the industrial lens and the maximum field of view FOV: G1 / (f G2 *f))*tan(FOV / 3)=0.0752, satisfying 0.05≤(f G1 / (fG2 *f))*tan(FOV / 3)≤0.08; The effective focal length f of the first lens group 1 u1 and the effective focal length f of the second lens group 2 u2 The relationship between: |f u1 / f u2 |=0.8183, satisfying 0.8≤|f u1 / f u2 |≤2.8; and Figure 8 The total optical length TTL of the industrial lens is 41.82273mm, satisfying TTL≤42mm.

[0084] like Fig. 9 The MTF diagram of Example 3 is shown, and the horizontal axis is the distance from the center of the image field to the edge of the image field. It can be seen from the figure that at 60lp / mm, the optical transfer function is greater than 0.6, and the clarity of the image is guaranteed, reflecting that the industrial lens has a high resolution.

[0085] Fig.10 This is a relative illumination diagram of the present embodiment 3. It can be seen from the diagram that the relative brightness of the edge field of view is greater than 60%, so the imaging effect is good.

[0086] Depend on Fig. 9 and Fig.10 It can be seen that the industrial lens of this embodiment has the effects of high resolution and high relative illumination, improves the clarity of imaging, has high imaging quality and good optical performance.

[0087] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An industrial lens, characterized in that: The invention comprises a first lens group (1) and a second lens group (2) which are coaxially arranged, wherein an aperture (3) is arranged between the first lens group (1) and the second lens group (2), wherein the first lens group (1) comprises a first lens (4), a second lens (5) and a third lens (6) which are arranged in sequence from the object side to the image side, wherein the first lens (4) and the second lens (5) have positive focal powers, and the third lens (6) has negative focal powers; The second lens group (2) comprises a fourth lens (7), a fifth lens (8), a sixth lens (9) and a seventh lens (10) which are arranged in sequence from the object side to the image side, the fourth lens (7) and the seventh lens (10) having negative optical power, and the fifth lens (8) and the sixth lens (9) having positive optical power; Industrial lenses satisfy the following relationship: IH / FNO≥3.12; |f u1 / f|≤2.1; |f u2 / f|≥0.65; FOV / (D*TTL)≥0.03; Wherein, IH is the maximum image plane height of the industrial lens, FNO is the aperture value of the industrial lens, and 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 entire industrial lens, FOV is the maximum field of view of the industrial lens, D is the head aperture size of the industrial lens, and TTL is the total optical length of the industrial lens.

2. An industrial lens according to claim 1, characterized in that: The industrial lens also satisfies the following relationship: 8≤|f u1 / f u2 |≤2.8。 3. An industrial lens according to claim 1, characterized in that: The second lens (5) is a double convex positive lens, the third lens (6) is a double concave negative lens, and the second lens (5) and the third lens (6) form a first cemented lens group.

4. An industrial lens according to claim 3, characterized in that: The fourth lens (7) is a double concave negative lens, the fifth lens (8) is a double convex positive lens, and the fourth lens (7) and the fifth lens (8) form a second cemented lens group.

5. An industrial lens according to claim 4, characterized in that: The industrial lens also satisfies the following relationship: 05≤(f G1 / (f G2 *f))*tan(FOV / 3)≤0.08; Among them, is the effective focal length of the first cemented lens group in the industrial lens, and is the effective focal length of the second cemented lens group in the industrial lens.

6. An industrial lens according to claim 4, characterized in that: The second lens (5), the third lens (6), the fourth lens (7) and the fifth lens (8) are all glass lenses.

7. An industrial lens according to claim 1, characterized in that: The first lens (4) is a positive meniscus lens convex toward the object side, the second lens (5) is a double convex positive lens, the third lens (6) is a double concave negative lens, the fourth lens (7) is a double concave negative lens, the fifth lens (8) is a double convex positive lens, the sixth lens (9) is a double convex positive lens, and the seventh lens (10) is a negative meniscus lens convex toward the image side.

8. The industrial lens according to claim 1, characterized in that: The first lens (4) is a positive meniscus lens convex toward the object side, the second lens (5) is a double convex positive lens, the third lens (6) is a double concave negative lens, the fourth lens (7) is a double concave negative lens, the fifth lens (8) is a double convex positive lens, the sixth lens (9) is a double convex positive lens, and the seventh lens (10) is a double concave negative lens.

9. The industrial lens according to claim 1, characterized in that: The first lens (4) is a biconvex positive lens, the second lens (5) is a biconvex positive lens, the third lens (6) is a biconcave negative lens, the fourth lens (7) is a biconcave negative lens, the fifth lens (8) is a biconvex positive lens, the sixth lens (9) is a biconvex positive lens, and the seventh lens (10) is a meniscus negative lens convex toward the image side.

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