Machine vision optical system and camera module using the same

Abstract

The application provides a kind of machine vision optical system and its application camera module, mainly by 7 lenses, the first lens is convex on object side, concave on image side, and the focal power is negative, the second lens is convex on object side, concave on image side, and the focal power is negative, the third lens is concave on object side, convex on image side, and the focal power is positive, the fourth lens is convex on object side and image side, and the focal power is positive, the fifth lens is convex on object side and image side, and the focal power is positive, the sixth lens is concave on object side and image side, and the focal power is negative, the seventh lens is convex on object side, concave on image side, and the focal power is positive, the number of lenses is reasonable, the structure is simple, by reasonably distributing the focal power of lens, effectively meet the design requirements of ultra-wide angle and miniaturization of optical system, the high-pixel machine vision recognition optical system configured by the application has the advantages of high pixel, strong resolution and ultra-wide angle design, compact structure, easy to process and install, further improve the imaging effect of the system equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging, in particular to a machine vision optical system and a camera module using the same. BACKGROUND

[0002] Kinetic games are popular in European and American countries, and gradually spread to Asian and European countries. New kinetic games can simulate three-dimensional scenes, control the actions of characters in the game through their own body movements, and let players fully immerse themselves in the game and enjoy green and healthy games. Because the audience is extensive, it has broad market development prospects. As the core component of the kinetic game device, the camera lens also has broad development prospects. Therefore, how to provide a high-pixel, ultra-wide-angle and small-sized high-performance system has become the goal of everyone's pursuit. SUMMARY

[0003] The present application aims to provide a machine vision optical system with high pixels, ultra-wide angle and small size.

[0004] To achieve the purpose, the present application adopts the following technical solutions:

[0005] A machine vision optical system, sequentially comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens along the optical axis from the object plane to the image plane;

[0006] The object plane side of the first lens is convex, and the image plane side is concave, and the focal power thereof is negative;

[0007] The object plane side of the second lens is convex, and the image plane side is concave, and the focal power thereof is negative;

[0008] The object plane side of the third lens is concave, and the image plane side is convex, and the focal power thereof is positive;

[0009] The object plane side and the image plane side of the fourth lens are both convex, and the focal power thereof is positive;

[0010] The object plane side and the image plane side of the fifth lens are both convex, and the focal power thereof is positive;

[0011] The object plane side and the image plane side of the sixth lens are both concave, and the focal power thereof is negative;

[0012] The object plane side of the seventh lens is convex, and the image plane side is concave, and the focal power thereof is positive.

[0013] Further, each lens of the optical system satisfies the following conditions:

[0014] -6.5 mm < f1 < -2.5 mm;

[0015] -16.3 mm < f2 < -10 mm;

[0016] 50 mm < f3 < 130 mm;

[0017] 3.50 mm < f4 < 6.5 mm;

[0018] 1.5 mm < f5 < 3.5 mm;

[0019] -3.5 mm < f6 < -1.5 mm;

[0020] 13 mm < f7 < 30 mm;

[0021] wherein, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

[0022] Further, the radius of curvature R1 of the first lens on the object side satisfies: R1 < 11 mm.

[0023] Further, the optical system satisfies the following condition: TTL ≤ 15.9 mm;

[0024] wherein, TTL is the on-axis distance from the object side of the first lens to the image plane.

[0025] Further, each lens of the optical system satisfies the following condition:

[0026] 1.5 < Nd1 < 2.1, 20.00 < Vd1 < 50;

[0027] 1.51 < Nd2 < 1.62, 52.50 < Vd2 < 58.00;

[0028] 1.61 < Nd3 < 2.1, 16 < Vd3 < 35;

[0029] 1.45 < Nd4 < 1.65, 53.5 < Vd4 < 70;

[0030] 1.51 < Nd5 < 1.62, 52.50 < Vd5 < 58.00;

[0031] 1.61 < Nd6 < 2.1, 16 < Vd6 < 35;

[0032] 1.51 < Nd7 < 1.62, 52.50 < Vd7 < 58.00;

[0033] Wherein, Nd1 is the refractive index of the first lens, Vd1 is the Abbe number of the first lens; Nd2 is the refractive index of the second lens, Vd2 is the Abbe number of the second lens; Nd3 is the refractive index of the third lens, Vd3 is the Abbe number of the third lens; Nd4 is the refractive index of the fourth lens, Vd4 is the Abbe number of the fourth lens; Nd5 is the refractive index of the fifth lens, Vd5 is the Abbe number of the fifth lens; Nd6 is the refractive index of the sixth lens, Vd6 is the Abbe number of the sixth lens; Nd7 is the refractive index of the seventh lens, Vd7 is the Abbe number of the seventh lens.

[0034] Further, the fourth lens is a spherical lens.

[0035] Further, the FNO of the optical system satisfies: FNO≤2.1.

[0036] Further, the full field of view FOV of the optical system satisfies: 185°≤FOV.

[0037] Further, the fifth lens and the sixth lens are cemented lenses.

[0038] Further, the refractive index Nd and the Abbe number Vd of the two lenses of the cemented lens satisfy: 1.51<Nd5<1.62, 52.50<Vd5<58.00; 1.61<Nd6<2.1, 16<Vd6<35.

[0039] In another aspect, the embodiment of the present application also provides a camera module, which at least comprises an optical lens, and the optical lens is internally mounted with the machine vision optical system.

[0040] Compared with the prior art, the beneficial effects of the present application are as follows:

[0041] The present application provides a machine vision optical system and a camera module using the same, which is mainly composed of seven lenses, the number of lenses is reasonable, the structure is simple, and the design requirements of ultra-wide angle and miniaturization of the optical system are effectively met by reasonably distributing the optical power of the lenses. The optical system configured by the present application has the advantages of high pixel, strong resolution and ultra-wide angle design, and the structure is compact, which is convenient for processing and installation, and further improves the imaging effect of the equipment matched with the system. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows.

[0043] Figure 1 is a structural schematic diagram of the optical system or the camera lens of the embodiment 1 of the present application;

[0044] Figure 2is a field curvature and distortion curve diagram of the optical system or camera lens of Embodiment 1 of the present application;

[0045] Figure 3 is an MTF curve diagram of the optical system or camera lens of Embodiment 1 of the present application;

[0046] Figure 4 is a structural schematic diagram of the optical system or camera lens of Embodiment 2 of the present application;

[0047] Figure 5 is a field curvature and distortion curve diagram of the optical system or camera lens of Embodiment 2 of the present application;

[0048] Figure 6 is an MTF curve diagram of the optical system or camera lens of Embodiment 2 of the present application;

[0049] Figure 7 is a structural schematic diagram of the optical system or camera lens of Embodiment 3 of the present application;

[0050] Figure 8 is a field curvature and distortion curve diagram of the optical system or camera lens of Embodiment 3 of the present application;

[0051] Figure 9 is an MTF curve diagram of the optical system or camera module of Embodiment 3 of the present application. DETAILED DESCRIPTION

[0052] As shown in Figures 1-9 , the present application provides a machine vision optical system, which is composed of a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a stop STO, a fifth lens E5, a sixth lens E6 and a seventh lens E7 in sequence along an optical axis from an object plane to an image plane;

[0053] The object plane side of the first lens is convex, the image plane side is concave, and the optical power thereof is negative;

[0054] The object plane side of the second lens is convex, the image plane side is concave, and the optical power thereof is negative;

[0055] The object plane side of the third lens is concave, the image plane side is convex, and the optical power thereof is positive;

[0056] The object plane side and the image plane side of the fourth lens are both convex, and the optical power thereof is positive;

[0057] The object plane side and the image plane side of the fifth lens are both convex, and the optical power thereof is positive;

[0058] The object plane side and the image plane side of the sixth lens are both concave, and the optical power thereof is negative;

[0059] The object plane side of the seventh lens is convex, the image plane side is concave, and the optical power thereof is positive.

[0060] The optical system of the embodiment of the application is mainly composed of 7 lenses, the number of lenses is reasonable, the structure is simple, the optical power of the lenses is reasonably distributed, the design requirements of the optical system for ultra-wide angle and miniaturization are effectively met, the optical system configured by the application for high-pixel machine vision recognition has the advantages of high pixel, strong resolution, ultra-wide angle design, compact structure, convenient processing and installation, and the imaging effect of the equipment matched with the system is further improved.

[0061] Further, as a preferred embodiment of the application but not limited, each lens of the optical system satisfies the following conditions: wherein, f1 is the focal length of the first lens E1, f2 is the focal length of the second lens E2, f3 is the focal length of the third lens E3, f4 is the focal length of the fourth lens E4, f5 is the focal length of the fifth lens E5, f6 is the focal length of the sixth lens E6, and f7 is the focal length of the seventh lens E7.

[0062] -6.5mm < f1 < -2.5 mm, by constraining the effective focal length of the first lens E1 in a reasonable range, the distortion of the system is controlled, and the center of the imaging has higher angular resolution;

[0063] -16.3 mm < f2 < -10 mm; by constraining the effective focal length of the second lens E2 in a reasonable range, the lens aberration is optimized, and the imaging quality is improved;

[0064] 50 mm < f3 < 130 mm; by constraining the effective focal length of the third lens E3 in a reasonable range, the spherical aberration of the system is fine-tuned and controlled, and the imaging quality of the system is effectively improved;

[0065] 3.50 mm < f4 < 6.5 mm; by reasonably controlling the effective focal length of the fourth lens E4 in a reasonable range, the imaging quality of the system is effectively improved;

[0066] 1.5 mm < f5 < 3.5 mm; by constraining the effective focal length of the fifth lens E5 in a reasonable range, the imaging quality is improved;

[0067] -3.5 mm < f6 < -1.5 mm; by constraining the effective focal length of the sixth lens E6 in a reasonable range, the lens aberration is optimized, and the resolution performance is improved;

[0068] 13 mm < f7 < 30 mm; by constraining the effective focal length of the seventh lens E7 in a reasonable range, the lens aberration is optimized, and the field curvature of the system is improved.

[0069] Further, the first lens E1 has a refractive index Nd1 and an Abbe number Vd1 satisfying 1.5 < Nd1 < 2.1 and 20.00 < Vd1 < 50, which can effectively reduce chromatic aberration, optimize lens aberration, and improve the imaging quality of the system.

[0070] Further, the second lens E2 has a refractive index Nd2 and an Abbe number Vd2 satisfying 1.51 < Nd2 < 1.62 and 52.50 < Vd2 < 58.00, which can effectively reduce chromatic aberration, optimize lens aberration, and improve the imaging quality of the system.

[0071] Further, the third lens E3 has a refractive index Nd3 and an Abbe number Vd3 satisfying 1.61 < Nd3 < 2.1 and 16 < Vd3 < 35, which can effectively reduce chromatic aberration, optimize lens aberration, and improve the imaging quality of the system.

[0072] Further, the fourth lens E4 has a refractive index Nd4 and an Abbe number Vd4 satisfying 1.45 < Nd4 < 1.65 and 53.5 < Vd4 < 70, which can effectively reduce chromatic aberration, optimize lens aberration, and improve the imaging quality of the system.

[0073] Further, the fifth lens E5 has a refractive index Nd5 and an Abbe number Vd5 satisfying 1.51 < Nd5 < 1.62 and 52.50 < Vd5 < 58.00, which can effectively reduce chromatic aberration, optimize lens aberration, and improve the imaging quality of the system.

[0074] Further, the sixth lens E6 has a refractive index Nd6 and an Abbe number Vd6 satisfying 1.61 < Nd6 < 2.1 and 16 < Vd6 < 35, which can effectively reduce chromatic aberration, optimize lens aberration, and improve the imaging quality of the system.

[0075] Further, the seventh lens E7 has a refractive index Nd7 and an Abbe number Vd7 satisfying 1.51 < Nd7 < 1.62 and 52.50 < Vd7 < 58.00, which can effectively reduce chromatic aberration, optimize lens aberration, and improve the imaging quality of the system.

[0076] Further, as a preferred embodiment of the present application, the fourth lens E4 is a spherical surface, which can optimize lens aberration and improve the resolving performance by reasonably distributing the focal length of the lens.

[0077] Further, as a preferred embodiment of the present application, the curvature radius R1 of the object side of the first lens satisfies R1 < 11 mm, which can reasonably control the total deflection angle of the object side of the first lens 1 at the edge field within a reasonable range by controlling the object side of the first lens E1.

[0078] Further, as a preferred embodiment of the present application but not limited, the optical system satisfies the condition: TTL ≤ 15.9mm, which can reduce the total optical length and make the lens smaller, so that the small wide-angle lens has more competitiveness in the market.

[0079] Further, as a preferred embodiment of the present application but not limited, the full field angle FOV of the optical system satisfies: 185° ≤ FOV and FNO ≤ 2.1, which is beneficial to expand the field of view of the lens and improve the light transmittance of the lens.

[0080] Further, as a preferred embodiment of the present application but not limited, the refractive index Nd and Abbe number Vd of the two lenses satisfy: 1.51 < Nd5 < 1.62, 52.50 < Vd5 < 58.00; 1.61 < Nd6 < 2.1, 16 < Vd6 < 35, which can effectively reduce chromatic aberration by increasing the difference between the refractive index and Abbe number of the lenses.

[0081] Specifically, as a preferred embodiment of the present application but not limited, Figure 1 The structure diagram of the optical imaging lens according to the embodiment 1 of the present application is shown in FIG. 1. Figure 1 As shown in FIG. 1, the object side S1 of the first lens E1 is a convex surface, the image side S2 is a concave surface, and the optical power is negative; the object side S1 of the second lens E2 is a convex surface, the image side S2 is a concave surface, and the optical power is negative; the object side S1 of the third lens E3 is a concave surface, the image side S2 is a convex surface, and the optical power is positive; the object side S1 and the image side S2 of the fourth lens E4 are both convex surfaces, and the optical power is positive; the object side and the image side of the fifth lens E5 are both convex surfaces, and the optical power is positive; the object side and the image side of the sixth lens E6 are both concave surfaces, and the optical power is negative; the object side S1 of the seventh lens E7 is convex, the image side S2 is concave, and the optical power is positive; the filter E7; the light from the object sequentially passes through each surface and finally forms an image on the imaging surface.

[0082] Table 1 shows the surface type, curvature radius, thickness and material of each lens of the optical imaging lens of the embodiment 1, wherein the units of the curvature radius and the thickness are millimeters (mm):

[0083] Table 1: basic parameters of the optical system of the embodiment 1

[0084]

[0085] In the above table 1, the object side and the image side of each of the second lens E2, the third lens E3, the fifth lens E5, the sixth lens E6 and the seventh lens E7 are aspherical surfaces, and the surface type of each aspherical lens can be defined by but not limited to the following aspherical formula:

[0086]

[0087] wherein x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th high order term in the aspherical surface formula. Table 2 shows the conic coefficients and high order term coefficients A4, A6, A8, A10, A12, A14, A16, A20 of the aspherical surfaces used in Embodiment 1.

[0088] Table 2: Aspherical surface related values of the lens in Embodiment 1

[0089]

[0090] Figure 2 The astigmatism and distortion curves of the optical imaging lens of Embodiment 1 are shown. The astigmatism represents the meridional image surface curvature and sagittal image surface curvature; the distortion represents the distortion size values corresponding to different image heights.

[0091] Figure 3 The MTF curves of the optical imaging lens of Embodiment 1 are shown, which represent the meridional and sagittal direction MTF values at different fields of view.

[0092] From Figure 2 and Figure 3 It can be seen that the optical lens given in Embodiment 1 can achieve good imaging quality.

[0093] Specifically, as a preferred embodiment of the present application but not limited, Figure 4 The structure diagram of the optical imaging lens according to Embodiment 2 of the present application is shown, as shown in Figure 4 The object side S1 of the first lens E1 is a convex surface, the image side S2 is a concave surface, and the optical power is negative; the object side S1 of the second lens E2 is a convex surface, the image side S2 is a concave surface, and the optical power is negative; the object side S1 of the third lens E3 is a concave surface, the image side S2 is a convex surface, and the optical power is positive; the object side S1 and the image side S2 of the fourth lens E4 are both convex surfaces, and the optical power is positive; the object side and the image side of the fifth lens E5 are both convex surfaces, and the optical power is positive; the object side and the image side of the sixth lens E6 are both concave surfaces, and the optical power is negative; the object side S1 of the seventh lens E7 is convex, the image side S2 is concave, and the optical power is positive; the filter E7; the light from the object sequentially passes through each surface and finally forms an image on the imaging surface.

[0094] Table 3 shows the surface type, curvature radius, thickness and material of each lens of the optical imaging lens of Embodiment 2, wherein the units of the curvature radius and the thickness are millimeters (mm):

[0095] Table 3: Basic parameters of the optical system of Example 2

[0096]

[0097] In the above Table 3, the object side surface and the image side surface of each of the second lens E2, the fourth lens E4, the fifth lens E5, the sixth lens E6 and the seventh lens E7 are aspherical surfaces, and the surface shape of each aspherical surface can be defined by, but is not limited to, the following aspherical surface formula:

[0098]

[0099] wherein x is the distance from the corresponding point on the aspherical surface to the tangent plane at the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature at the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th high order term in the aspherical surface formula. Table 4 shows the conic coefficients and the high order term coefficients A4, A6, A8, A10, A12, A14, A16 and A20 of the aspherical surfaces used in Example 2.

[0100] Table 4: Aspherical surface related values of the lenses in Example 2

[0101]

[0102] Figure 5 The astigmatism and distortion curves of the optical imaging lens of Example 2 are shown. The astigmatism represents the meridional image surface curvature and the sagittal image surface curvature; the distortion represents the distortion size values corresponding to different image heights.

[0103] Figure 6 The MTF curves of the optical imaging lens of Example 2 are shown, which represent the meridional and sagittal MTF values at different fields of view.

[0104] From Figure 5 and Figure 6 It can be seen that the optical lens given in Example 2 can achieve good imaging quality.

[0105] Specifically, as a preferred embodiment of the present application but not limited, Figure 7 The structure of the optical imaging lens according to Example 3 of the present application is shown in the schematic diagram, as Figure 4As shown, the object side S1 of the first lens E1 is convex, the image side S2 is concave, and the optical power is negative; the object side S1 of the second lens E2 is convex, the image side S2 is concave, and the optical power is negative; the object side S1 of the third lens E3 is concave, the image side S2 is convex, and the optical power is positive; the object side S1 and the image side S2 of the fourth lens E4 are both convex, and the optical power is positive; the object side and the image side of the fifth lens E5 are both convex, and the optical power is positive; the object side and the image side of the sixth lens E6 are both concave, and the optical power is negative; the object side S1 of the seventh lens E7 is convex, the image side S2 is concave, and the optical power is positive; the filter E7; the light from the object sequentially passes through each surface and finally forms an image on the imaging surface.

[0106] Table 5 shows the surface type, radius of curvature, thickness and material of each lens of the optical imaging lens of Example 3, wherein the units of the radius of curvature and the thickness are millimeters (mm):

[0107] Table 5: Basic parameters of the optical system of Example 3

[0108]

[0109] In Table 5 above, the object side and the image side of any one of the second lens E2, the fourth lens E4, the fifth lens E5, the sixth lens E6 and the seventh lens E7 are aspherical surfaces, and the surface type of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0110]

[0111] wherein x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th high order term in the aspherical surface formula. Table 6 shows the conic coefficient and the high order term coefficients A4, A6, A8, A10, A12, A14, A16 and A20 of each aspherical surface that can be used in Example 3.

[0112] Table 6: Aspherical surface related values of the lenses of Example 3

[0113]

[0114] Figure 8 The astigmatism and distortion curves of the optical imaging lens of Example 3 are shown. The astigmatism represents the meridional image curvature and the sagittal image curvature; the distortion represents the distortion size values corresponding to different image heights.

[0115] Figure 9 The MTF curves of the optical imaging lens of Example 3 are shown, which represent the meridional and sagittal MTF values at different fields of view.

[0116] By Figure 8 And Figure 9 It can be seen that the optical lens given in embodiment 3 can achieve good imaging quality.

[0117] In embodiments 1-3, the basic data is shown in Table 7:

[0118] Table 7 Basic data of embodiments 1-3

[0119]

[0120] A camera lens at least comprises an optical lens, and the optical lens is installed with the machine vision optical system. The camera lens provided by the embodiment of the application has reasonable number of lenses, simple structure, and effectively meets the design requirements of the optical system for ultra-wide angle and miniaturization by reasonably distributing the optical power of the lenses. The optical system configured in the application has the advantages of high pixel, strong resolution, and ultra-wide angle design. The structure is compact, easy to process and install, and further improves the imaging effect of the equipment matched with the system.

[0121] The above only describes the preferred embodiments of the application and is not intended to limit the application. Any modification, equivalent replacement, and improvement within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A machine vision optical system, sequentially comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens along an optical axis from an object plane to an image plane, characterized in that: the first lens has a convex object side and a concave image side, and has a negative focal power; the second lens has a convex object side and a concave image side, and has a negative focal power; the third lens has a concave object side and a convex image side, and has a positive focal power; the fourth lens has a convex object side and a convex image side, and has a positive focal power; the fifth lens has a convex object side and a convex image side, and has a positive focal power; the sixth lens has a concave object side and a concave image side, and has a negative focal power; the seventh lens has a convex object side and a concave image side, and has a positive focal power; each lens of the optical system satisfies the following conditions: -6.5 mm < f1 < -2.5 mm; -16.3 mm < f2 < -10 mm; 50 mm < f3 < 130 mm; 3.50 mm < f4 < 6.5 mm; 1.5 mm < f5 < 3.5 mm; -3.5 mm < f6 < -1.5 mm; 13 mm < f7 < 30 mm; wherein, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens. The first lens has a convex object side and a concave image side, and has a negative focal power; the second lens has a convex object side and a concave image side, and has a negative focal power; the third lens has a concave object side and a convex image side, and has a positive focal power; the fourth lens has a convex object side and a convex image side, and has a positive focal power; the fifth lens has a convex object side and a convex image side, and has a positive focal power; the sixth lens has a concave object side and a concave image side, and has a negative focal power; the seventh lens has a convex object side and a concave image side, and has a positive focal power; each lens of the optical system satisfies the following conditions: -6.5 mm < f1 < -2.5 mm; -16.3 mm < f2 < -10 mm; 50 mm < f3 < 130 mm; 3.50 mm < f4 < 6.5 mm; 1.5 mm < f5 < 3.5 mm; -3.5 mm < f6 < -1.5 mm; 13 mm < f7 < 30 mm; wherein, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens. The first lens has a convex object side and a concave image side, and has a negative focal power; the second lens has a convex object side and a concave image side, and has a negative focal power; the third lens has a concave object side and a convex image side, and has a positive focal power; the fourth lens has a convex object side and a convex image side, and has a positive focal power; the fifth lens has a convex object side and a convex image side, and has a positive focal power; the sixth lens has a concave object side and a concave image side, and has a negative focal power; the seventh lens has a convex object side and a concave image side, and has a positive focal power; each lens of the optical system satisfies the following conditions: -6.5 mm < f1 < -2.5 mm; -16.3 mm < f2 < -10 mm; 50 mm < f3 < 130 mm; 3.50 mm < f4 < 6.5 mm; 1.5 mm < f5 < 3.5 mm; -3.5 mm < f6 < -1.5 mm; 13 mm < f7 < 30 mm; wherein, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens. The first lens has a convex object side and a concave image side, and has a negative focal power; the second lens has a convex object side and a concave image side, and has a negative focal power; the third lens has a concave object side and a convex image side, and has a positive focal power; the fourth lens has a convex object side and a convex image side, and has a positive focal power; the fifth lens has a convex object side and a convex image side, and has a positive focal power; the sixth lens has a concave object side and a concave image side, and has a negative focal power; the seventh lens has a convex object side and a concave image side, and has a positive focal power; each lens of the optical system satisfies the following conditions: -6.5 mm < f1 < -2.5 mm; -16.3 mm < f2 < -10 mm; 50 mm < f3 < 130 mm; 3.50 mm < f4 < 6.5 mm; 1.5 mm < f5 < 3.5 mm; -3.5 mm < f6 < -1.5 mm; 13 mm < f7 < 30 mm; wherein, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The machine vision optical system of claim 1, wherein: ​ 3. The machine vision optical system of claim 1, wherein: ​ ​ 4. The machine vision optical system according to any one of claims 1-3, wherein: ​ ​ ​ ​ ​ ​ ​ ​ ​ 5. The machine vision optical system according to any of claims 1-3, characterized in that: ​ 6. The machine vision optical system according to any one of claims 1-3, wherein: ​ 7. The machine vision optical system according to any one of claims 1-3, wherein: ​ 8. The machine vision optical system of claim 7, wherein: The refractive index Nd and Abbe number Vd of the two lenses of the glued lens satisfy: 1.51 < Nd5 < 1.62, 52.50 < Vd5 < 58.00; 1.61 < Nd6 < 2.1, 16 < Vd6 < 35.

9. An image capturing module comprising at least an optical lens, characterized in that: The machine vision optical system of any one of claims 1-8 is installed in the optical lens.

Images