An industrial lens

Abstract

The application discloses an industrial lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens; the first lens, the fifth lens, the seventh lens and the ninth lens are positive focal power lenses; the third lens, the fourth lens and the sixth lens are negative focal power lenses; the focal power of the second lens is positive or negative, and the focal power of the eighth lens is positive or negative; the first lens, the second lens, the third lens and the fourth lens are convex-concave surface type lenses, the object side surface of the fifth lens is a convex surface, the image side surface of the sixth lens is a concave surface, the object side surface of the seventh lens is a convex surface, the image side surface of the eighth lens is a convex surface, and the ninth lens is a double-convex surface type lens. By reasonably setting the number of lenses contained in the lens, the focal power matching mode of each lens and the surface matching mode, the industrial lens with high image quality imaging performance can be realized.

Description

Technical Field

[0001] This invention relates to the field of optical device technology, and more particularly to an industrial lens. Background Technology

[0002] In recent years, with the development of industrial automation, the market demand for lenses that can have a sufficiently large scanning range while also capturing fine details has increased significantly. Currently, most of these lenses on the market suffer from low scanning accuracy due to uncontrollable distortion or significant color difference. Summary of the Invention

[0003] This invention provides an industrial lens that achieves high image quality imaging performance.

[0004] This invention provides an industrial lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially along the optical axis from the object plane to the image plane; the first lens, the fifth lens, the seventh lens, and the ninth lens are positive power lenses; the third lens, the fourth lens, and the sixth lens are negative power lenses; the second lens is either a positive power lens or a negative power lens; and the eighth lens is either a positive power lens or a negative power lens.

[0005] The first lens includes a first object-side surface near the object plane and a first image-side surface near the image plane. The first object-side surface is convex, and the first image-side surface is concave.

[0006] The second lens includes a second object-side surface near the object plane and a second image-side surface near the image plane, wherein the second object-side surface is convex and the second image-side surface is concave.

[0007] The third lens includes a third object-side surface near the object plane and a third image-side surface near the image plane. The third object-side surface is convex, and the third image-side surface is concave.

[0008] The fourth lens includes a fourth object-side surface near the object plane and a fourth image-side surface near the image plane. The fourth object-side surface is convex, and the fourth image-side surface is concave.

[0009] The fifth lens includes a fifth object-side surface near the object surface, and the fifth object-side surface is a convex surface;

[0010] The sixth lens includes a sixth image side surface near the image plane, and the sixth image side surface is concave.

[0011] The seventh lens includes a seventh object-side surface near the object surface, and the seventh object-side surface is convex.

[0012] The eighth lens includes an eighth image side surface near the image plane, and the eighth image side surface is convex.

[0013] The ninth lens includes a ninth object-side surface near the object plane and a ninth image-side surface near the image plane. The ninth object-side surface is convex, and the ninth image-side surface is convex.

[0014] Optionally, the fifth lens further includes a fifth image-side surface near the image plane, which is either convex or concave.

[0015] The sixth lens also includes a sixth object-side surface near the object surface, which is either convex or concave.

[0016] The seventh lens also includes a seventh image side surface near the image plane, which is either convex or concave.

[0017] The eighth lens also includes an eighth object-side surface near the object surface, which is either convex or concave.

[0018] Optionally, the focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, the focal length of the eighth lens is f8, the focal length of the ninth lens is f9, and the focal length of the industrial lens is f.

[0019] Among them, 4.19 <f1 / f<5.70,-1.49<f2 / f<13.32,-1.50<f3 / f<-1.23,-1.23<f4 / f<-0.66,0.64<f5 / f<1.10,-3.34<f6 / f<-1.00,0.96<f7 / f<1.45,-1.86<f8 / f<1.71,1.65<f9 / f<1.88。

[0020] Optionally, the first lens has a refractive index of Nd1 and an Abbe number of Vd1; the second lens has a refractive index of Nd2 and an Abbe number of Vd2; the third lens has a refractive index of Nd3 and an Abbe number of Vd3; the fourth lens has a refractive index of Nd4 and an Abbe number of Vd4; the fifth lens has a refractive index of Nd5 and an Abbe number of Vd5; the sixth lens has a refractive index of Nd6 and an Abbe number of Vd6; the seventh lens has a refractive index of Nd7 and an Abbe number of Vd7; the eighth lens has a refractive index of Nd8 and an Abbe number of Vd8; and the ninth lens has a refractive index of Nd9 and an Abbe number of Vd9.

[0021] Among them, 1.63≤Nd1≤1.91, 35≤Vd1≤73; 1.78≤Nd2≤2, 18≤Vd2≤37; 1.56≤Nd3≤1.75, 50≤Vd3≤75; 1.45≤Nd4≤1.62, 50≤Vd4≤97; 2≤Nd5≤2.01, 24.9≤Vd5≤35; 1.86≤Nd6≤1.96, 15.3≤Vd6≤24.8; 1.6≤Nd7≤2.05, 17≤Vd7≤58; 1.55≤Nd8≤1.75, 20.2≤Vd8≤80; 1.95≤Nd9≤2.02, 19.7≤Vd9≤25.5.

[0022] Optionally, the maximum field of view of the industrial lens is FOV, and the aperture number of the industrial lens is FNO;

[0023] Among them, 12.22≤FOV / FNO≤12.39.

[0024] Optionally, the distortion of the industrial lens is Dis;

[0025] Among them, 0.28%≤|Dis|≤0.58%.

[0026] Optionally, the back focal length of the industrial lens is BFL, and the total length of the industrial lens is TTL;

[0027] Wherein, 0.171≤BEL / TTL≤0.192.

[0028] Optionally, the fifth lens and the sixth lens are cemented together, and the seventh lens and the eighth lens are cemented together;

[0029] Alternatively, the sixth lens and the seventh lens may be cemented together.

[0030] Optionally, the first lens, the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens are all glass spherical lenses;

[0031] The fourth lens is a glass spherical lens or a glass aspherical lens.

[0032] Optionally, the industrial lens further includes an aperture stop, which is disposed in the optical path between the fifth lens and the sixth lens;

[0033] Alternatively, the aperture may be positioned in the optical path between the sixth lens and the seventh lens.

[0034] The industrial lens provided in this invention includes nine lenses with optical power. The arrangement of these nine lenses ensures a reasonable number of lenses in the optical system, preventing an excessively large lens size due to too many lenses, and avoiding significant aberrations caused by a single lens bearing too much optical power due to too few lenses. This ensures both miniaturization of the optical system and low imaging aberrations, resulting in high image quality. Furthermore, by rationally configuring the optical power and surface shape combinations of the lenses, not only can the aperture size of the optical system be effectively increased to achieve a large aperture, but the imaging quality of the optical system can also be further improved, enabling a miniaturized industrial lens design.

[0035] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of an industrial lens provided in Embodiment 1 of the present invention;

[0038] Figure 2 This is a schematic diagram of the axial aberration of an industrial lens provided in Embodiment 1 of the present invention;

[0039] Figure 3 This is a schematic diagram of the vertical chromatic aberration of an industrial lens provided in Embodiment 1 of the present invention;

[0040] Figure 4 This is a schematic diagram of field curvature distortion of an industrial lens provided in Embodiment 1 of the present invention;

[0041] Figure 5 This is a schematic diagram of the structure of an industrial lens provided in Embodiment 2 of the present invention;

[0042] Figure 6 This is a schematic diagram of the axial aberration of an industrial lens provided in Embodiment 2 of the present invention;

[0043] Figure 7 This is a schematic diagram of the vertical chromatic aberration of an industrial lens provided in Embodiment 2 of the present invention;

[0044] Figure 8 This is a schematic diagram of field curvature distortion of an industrial lens provided in Embodiment 2 of the present invention;

[0045] Figure 9 This is a schematic diagram of the structure of an industrial lens provided in Embodiment 3 of the present invention;

[0046] Figure 10 This is a schematic diagram of the axial aberration of an industrial lens provided in Embodiment 3 of the present invention;

[0047] Figure 11 This is a schematic diagram of the vertical chromatic aberration of an industrial lens provided in Embodiment 3 of the present invention;

[0048] Figure 12 This is a schematic diagram of field curvature distortion of an industrial lens provided in Embodiment 3 of the present invention. Detailed Implementation

[0049] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0050] Example 1

[0051] Figure 1 This is a schematic diagram of the structure of an industrial lens provided in Embodiment 1 of the present invention, as shown below. Figure 1As shown, the industrial lens provided in this embodiment of the invention includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106, a seventh lens 107, an eighth lens 108, and a ninth lens 109 arranged sequentially along the optical axis from the object plane to the image plane; the first lens 101, the fifth lens 105, the seventh lens 107, and the ninth lens 109 are positive power lenses; the third lens 103, the fourth lens 104, and the sixth lens 106 are negative power lenses; the second lens 102 is either a positive power lens or a negative power lens, and the eighth lens 108 is either a positive power lens or a negative power lens; the first lens 101 includes a first object-side surface near the object plane and a first image-side surface near the image plane, the first object-side surface being convex and the first image-side surface being concave; the second lens 102 includes a second object-side surface near the object plane and a second image-side surface near the image plane. The second object-side surface is convex, and the second image-side surface is concave; the third lens 103 includes a third object-side surface near the object surface and a third image-side surface near the image surface, the third object-side surface being convex and the third image-side surface being concave; the fourth lens 104 includes a fourth object-side surface near the object surface and a fourth image-side surface near the image surface, the fourth object-side surface being convex and the fourth image-side surface being concave; the fifth lens 105 includes a fifth object-side surface near the object surface, the fifth object-side surface being convex; the sixth lens 106 includes a sixth image-side surface near the image surface, the sixth image-side surface being concave; the seventh lens 107 includes a seventh object-side surface near the object surface, the seventh object-side surface being convex; the eighth lens 108 includes an eighth image-side surface near the image surface, the eighth image-side surface being convex; the ninth lens 109 includes a ninth object-side surface near the object surface and a ninth image-side surface near the image surface, the ninth object-side surface being convex and the ninth image-side surface being convex.

[0052] Specifically, the industrial lens provided in this embodiment of the invention includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106, a seventh lens 107, an eighth lens 108, and a ninth lens 109. That is, the industrial lens includes nine lenses with optical power. The arrangement of nine lenses ensures that the number of lenses in the optical system is reasonable. Too many lenses will result in a large lens size, and too few lenses will result in large aberrations due to a single lens bearing a large optical power. This ensures that the optical system is miniaturized while ensuring small imaging aberrations and high imaging quality.

[0053] Furthermore, optical power is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam, characterizing the ability of an optical system to deflect light. The larger the absolute value of the optical power, the stronger the bending ability of light; the smaller the absolute value, the weaker the bending ability. When the optical power is positive, the refraction of light is converging; when the optical power is negative, the refraction of light is diverging. In this embodiment of the invention, the first lens 101 is a positive optical power lens, and its positive optical power setting can significantly correct the edge aberrations of the optical imaging system, thereby improving the imaging resolution of the optical system. When the second lens 102 is a positive optical power lens, the positive optical power setting of the second lens 102 can further correct the edge aberrations of the optical imaging system, further improving the imaging resolution of the optical system. When the second lens 102 is a negative power lens, the arrangement of the three negative power lenses—second lens 102, third lens 103, and fourth lens 104—can effectively deflect the outgoing light rays, which is beneficial for achieving a large image plane and a large aperture design. The positive power setting of the fifth lens 105, the negative power setting of the sixth lens 106, the positive power setting of the seventh lens 107, the positive or negative power setting of the eighth lens 108, and the positive power setting of the ninth lens 109, with their complementary positive and negative power functions, can balance the defects of the optical system and optimize imaging performance, such as correcting spherical aberration, chromatic aberration, and distortion. Furthermore, it can control the system length, enabling a compact design for industrial lenses.

[0054] Furthermore, the object-side surface of a lens can be understood as the surface of the lens closest to the object plane, and the image-side surface can be understood as the surface of the lens closest to the image plane. The object-side surface of the first lens 101 is convex, and the image-side surface is concave; the object-side surface of the second lens 102 is convex, and the image-side surface is concave; the object-side surface of the third lens 103 is convex, and the image-side surface is concave; the object-side surface of the fourth lens 104 is convex, and the image-side surface is concave. This can be understood as the object-side surfaces of the first lens 101, second lens 102, third lens 103, and fourth lens 104 all convex towards the object plane near the optical axis, and the image-side surfaces all concave towards the image plane near the optical axis. In other words, the first lens 101, second lens 102, third lens 103, and fourth lens 104 are all lenses with a convex-concave structure. The surface shapes of the first lens 101, second lens 102, third lens 103, and fourth lens 104, combined with their optical power settings, can converge light rays from a large field of view into the system as much as possible, which is beneficial for improving the field of view of the optical system. The object-side surface of the fifth lens 105 is convex, meaning that the object-side surface of the fifth lens 105 convexes towards the object plane at the near-optical axis position. The image-side surface of the sixth lens 106 is concave, meaning that the image-side surface of the sixth lens 106 is concave towards the image plane at the near-optical axis position. The object-side surface of the seventh lens 107 is convex, meaning that the object-side surface of the seventh lens 107 convexes towards the object plane at the near-optical axis position. The image-side surface of the eighth lens 108 is convex, meaning that the image-side surface of the eighth lens 108 convexes towards the image plane at the near-optical axis position. The object-side surface of the ninth lens 109 is convex, and the image-side surface is also convex, meaning that the object-side surface of the ninth lens 109 convexes towards the object plane at the near-optical axis position, and the image-side surface convexes towards the image plane at the near-optical axis position. The ninth lens 109 is a biconvex lens. By rationally setting the concave and convex surface shapes of each lens, on the one hand, the light propagation path can be modulated by the surface shape, optimizing the optical path and ensuring imaging effect; on the other hand, the distance between adjacent lenses can be reduced, which is beneficial for realizing the design of small-volume industrial lenses.

[0055] In summary, the industrial lens provided by this invention includes nine lenses with optical power. The arrangement of these nine lenses ensures a reasonable number of lenses in the optical system, preventing an excessively large lens size due to too many lenses, and avoiding significant aberrations caused by a single lens bearing too much optical power due to too few lenses. This approach ensures both miniaturization of the optical system and low imaging aberrations, resulting in high image quality. Furthermore, by rationally configuring the optical power and surface shape combinations of the lenses, not only can the aperture size of the optical system be effectively increased to achieve a large aperture, but the imaging quality of the optical system can also be further improved, enabling a miniaturized industrial lens design.

[0056] Based on the above embodiments, continue to refer to Figure 1As shown, the industrial lens provided in this embodiment of the invention also includes an aperture stop STO, which can be disposed in the optical path between the fifth lens 105 and the sixth lens 106; or, the aperture stop STO can be disposed in the optical path between the sixth lens 106 and the seventh lens 107.

[0057] like Figure 1 As shown, the optical system provided in this embodiment of the invention may further include an aperture stop STO. The aperture stop STO may be disposed in the optical path between the fifth lens 105 and the sixth lens 106, or in the optical path between the sixth lens 106 and the seventh lens 107. That is, the aperture stop STO is disposed in the optical system, which is beneficial to reduce the aperture value and achieve a large aperture.

[0058] Furthermore, when the aperture stop STO is set in the optical path between the fifth lens 105 and the sixth lens 106, the optical power of the fifth lens 105 can be positive. Combined with the negative optical power setting of the sixth lens 106, that is, the optical powers of the two lenses before and after the aperture stop STO are different, so as to achieve the effect of increasing the aperture size and eliminating advanced aberrations.

[0059] Alternatively, when the aperture stop STO is placed in the optical path between the sixth lens 106 and the seventh lens 107, since the sixth lens 106 is a negative optical power lens and the seventh lens 107 is a negative optical power lens, that is, the optical powers of the two lenses before and after the aperture stop STO are different, thus achieving the effect of increasing the aperture size and eliminating advanced aberrations.

[0060] Further reference Figure 1 As shown, the industrial lens provided in this embodiment of the invention may further include a filter 110. The filter 110 is disposed in the optical path between the ninth lens 109 and the image plane, and can filter out stray light and improve the imaging effect.

[0061] Furthermore, the industrial lens provided in this embodiment of the invention may also include a protective glass and an image acquisition element. The protective glass may be disposed on the image-side of the filter, and the image acquisition element may be disposed on the image-side of the protective glass. The optical system is protected by the protective glass, and images are acquired by the image acquisition element, thus enabling the optical system to perform its normal imaging function.

[0062] Based on the above embodiments, the fifth lens 105 further includes a fifth image-side surface near the image plane, which is convex or concave; the sixth lens 106 further includes a sixth object-side surface near the object plane, which is convex or concave; the seventh lens 107 further includes a seventh image-side surface near the image plane, which is convex or concave; and the eighth lens 108 further includes an eighth object-side surface near the object plane, which is convex or concave.

[0063] Specifically, the image-side surface of the fifth lens 105 is either convex or concave. That is, the image-side surface of the fifth lens 105 is convex or concave towards the image plane near the optical axis. Combined with the convex object-side surface of the fifth lens 105, this means the fifth lens 105 is a biconvex or convex-concave lens. Similarly, the object-side surface of the sixth lens 106 is either convex or concave. That is, the object-side surface of the sixth lens 106 is convex or concave towards the object plane near the optical axis. Combined with the concave image-side surface of the sixth lens 106, this means the sixth lens 106 is a convex-concave or biconcave lens. Likewise, the image-side surface of the seventh lens 107 is either convex or concave. That is, the image-side surface of the seventh lens 107 is convex or concave towards the image plane near the optical axis. Combined with the convex object-side surface of the seventh lens 107, this means the seventh lens 107 is a biconvex or convex-concave lens. The object-side surface of the eighth lens 108 is either convex or concave. That is, the object-side surface of the eighth lens 108 is convex or concave towards the object surface near the optical axis. Combined with the convex design of the image-side surface of the eighth lens 108, this means that the eighth lens 108 is a lens with a biconvex or concave-convex structure. By further refining the concave-convex shape of each lens, the optical path can be further optimized, improving the display effect; and the spacing between adjacent lenses can be further reduced, further enabling the design of a compact industrial lens.

[0064] Based on the above embodiments, the focal length of the first lens 101 is f1, the focal length of the second lens 102 is f2, the focal length of the third lens 103 is f3, the focal length of the fourth lens 104 is f4, the focal length of the fifth lens 105 is f5, the focal length of the sixth lens 106 is f6, the focal length of the seventh lens 107 is f7, the focal length of the eighth lens 108 is f8, the focal length of the ninth lens 109 is f9, and the focal length of the industrial lens is f; wherein, 4.19 <f1 / f<5.70,-1.49<f2 / f<13.32,-1.50<f3 / f<-1.23,-1.23<f4 / f<-0.66,0.64<f5 / f<1.10,-3.34<f6 / f<-1.00,0.96<f7 / f<1.45,-1.86<f8 / f<1.71,1.65<f9 / f<1.88。

[0065] Specifically, the focal length of a lens characterizes its ability to deflect light. A larger focal length results in a weaker ability to deflect light, while a smaller focal length results in a stronger ability. When the focal length is positive, the refraction of light is converging; when the focal length is negative, the refraction is diverging. Furthermore, this invention, through a reasonable allocation of lens focal lengths, can effectively reduce the overall aberrations of the optical system, ensuring a balance in the incident angles of the front and rear lenses, thereby reducing lens sensitivity and minimizing distortion. Moreover, the focal length allocation of the lenses in front of the aperture stop STO allows light to pass smoothly through the STO, reducing higher-order aberrations generated near the STO. The area behind the aperture stop further balances aberrations in the optical system, improving the imaging quality of the optical system.

[0066] Based on the above embodiments, the refractive index of the first lens 101 is Nd1, and the Abbe number is Vd1; the refractive index of the second lens 102 is Nd2, and the Abbe number is Vd2; the refractive index of the third lens 103 is Nd3, and the Abbe number is Vd3; the refractive index of the fourth lens 104 is Nd4, and the Abbe number is Vd4; the refractive index of the fifth lens 105 is Nd5, and the Abbe number is Vd5; the refractive index of the sixth lens 106 is Nd6, and the Abbe number is Vd6; the refractive index of the seventh lens 107 is Nd7, and the Abbe number is Vd7; the refractive index of the eighth lens 108 is Nd8, and the Abbe number is Vd8; and the refractive index of the ninth lens 109 is Nd9, and the Abbe number is Vd1. 9; where 1.63≤Nd1≤1.91, 35≤Vd1≤73; 1.78≤Nd2≤2, 18≤Vd2≤37; 1.56≤Nd3≤1.75, 50≤Vd3≤75; 1.45≤Nd4≤1.62, 50≤Vd4≤97; 2≤Nd5≤2.01, 24.9≤Vd5≤35; 1.86≤Nd6≤1.96, 15.3≤Vd6≤24.8; 1.6≤Nd7≤2.05, 17≤Vd7≤58; 1.55≤Nd8≤1.75, 20.2≤Vd8≤80; 1.95≤Nd9≤2.02, 19.7≤Vd9≤25.5.

[0067] Specifically, refractive index is the ratio of the speed of light in a vacuum to the speed of light in a medium, primarily used to describe a material's ability to refract light; different materials have different refractive indices. The Abbe number is an index used to represent the dispersion ability of a transparent medium; the more severe the dispersion, the smaller the Abbe number; conversely, the less severe the dispersion, the larger the Abbe number. This invention uses a large amount of high-refractive-index materials, which can effectively correct aberrations and further meet the high-resolution requirements of industrial lenses. Using a large number of high-refractive-index lenses also reduces the curvature of spherical lenses, thereby reducing the difficulty of lens manufacturing.

[0068] Based on the above embodiments, the maximum field of view (FOV) of the industrial lens is defined as FOV, and the aperture number is defined as FNO; where 12.22 ≤ FOV / FNO ≤ 12.39. These relationships limit the maximum field of view (FOV) and aperture number (FNO) of the lens, ensuring image quality with a large field of view at a sufficiently large aperture, further improving the overall image quality of the optical system. Limiting the ratio of FOV to FNO also further reduces the distortion of the optical system, achieving the low distortion effect required for industrial lenses.

[0069] Based on the above embodiments, the distortion of the industrial lens is Dis; wherein, 0.28%≤|Dis|≤0.58%. Distortion describes the deformation between the actual image plane and the ideal image plane. Controlling distortion can control the geometry of the image and also change the data quality of the image. The embodiments of the present invention ensure high imaging quality and low distortion by controlling the distortion data of the lens.

[0070] Based on the above embodiments, the back focal length of the industrial lens is BFL, and the total length of the industrial lens is TTL; wherein, 0.171≤BEL / TTL≤0.192. The reasonable selection of the back focal length and total length ensures that the lens meets the focal length requirements while guaranteeing sufficient installation space for the image acquisition element and flat panel filter. This also ensures that the lens will not interfere with the base and housing during installation, thus simplifying the assembly process of the industrial lens.

[0071] Based on the above embodiments, the fifth lens 105 and the sixth lens 106 are cemented together, and the seventh lens 107 and the eighth lens 108 are cemented together; or, the sixth lens 106 and the seventh lens 107 are cemented together.

[0072] Specifically, cemented lenses allow the image-side of one lens to be immediately bonded to the object-side of the next, resulting in identical surface shapes. For example, the cemented configuration of the fifth lens 105 and the sixth lens 106 can be understood as the image-side of the fifth lens 105 being bonded to the object-side of the sixth lens 106, resulting in identical surface shapes; similarly, the cemented configuration of the seventh lens 107 and the eighth lens 108 can be understood as the image-side of the seventh lens 107 being bonded to the object-side of the eighth lens 108, resulting in identical surface shapes; and the cemented configuration of the sixth lens 106 and the seventh lens 107 can be understood as the image-side of the sixth lens 106 being bonded to the object-side of the seventh lens 107, resulting in identical surface shapes. Cemented lenses can be used to minimize or eliminate chromatic aberration. In industrial lenses, the use of cemented lenses can improve image quality and reduce light energy reflection loss, thereby enhancing the sharpness of the lens image. Furthermore, the cementation of lenses eliminates the air gap between the two lenses, making the overall optical system compact and meeting the requirements for system miniaturization. Furthermore, the bonding of the lenses reduces tolerance sensitivity issues such as tilting / eccentricity that occur during the assembly of the lens units. For example, the fifth lens 105 and the sixth lens 106 can be bonded together using a spacer or by adhesive; the seventh lens 107 and the eighth lens 108 can be bonded together using a spacer or by adhesive; or, the sixth lens 106 and the seventh lens 107 can be bonded together using a spacer or by adhesive.

[0073] Based on the above embodiments, the first lens 101, the second lens 102, the third lens 103, the fifth lens 105, the sixth lens 106, the seventh lens 107, the eighth lens 108 and the ninth lens 109 are all glass spherical lenses; the fourth lens 104 is a glass spherical lens or a glass aspherical lens.

[0074] Specifically, spherical lenses are characterized by a constant curvature from the center to the periphery, ensuring a simple lens setup. Aspherical lenses, on the other hand, have a continuously changing curvature from the center to the periphery. Unlike spherical lenses, which have a constant curvature, aspherical lenses possess superior curvature radius characteristics, offering advantages in improving distortion and astigmatism.

[0075] Furthermore, due to the low coefficient of thermal expansion and good stability of glass lenses, all nine lenses with optical power in the optical system are glass lenses, which improves the stability of industrial lenses. In addition, compared to plastic lenses, glass offers a wider range of material options, with more freedom in choosing the refractive index and Abbe number. This allows for better control over higher aberrations and chromatic aberrations, meeting the needs of use under complex conditions.

[0076] Furthermore, the first lens 101, second lens 102, third lens 103, fifth lens 105, sixth lens 106, seventh lens 107, eighth lens 108, and ninth lens 109 are all glass spherical lenses. The thermal properties of glass spherical lenses are more stable, ensuring good resolving power over a wider temperature range when handling higher optical powers. Additionally, the fourth lens 104 is a glass aspherical lens, which meets the requirement of using a high Abbe number, reduces chromatic aberration in the optical system, and improves image quality.

[0077] As a feasible implementation method, the parameters of each lens in the industrial lens will be explained next.

[0078] Table 1. Optical design values ​​for an industrial lens in Example 1

[0079]

[0080] Table 2 Design values ​​of optical physical parameters for industrial lenses

[0081]

[0082] The surface numbers in Table 2 are assigned according to the surface sequence of each lens. "STO" represents the aperture stop of the lens. The radius of curvature represents the curvature of the corresponding lens surface. A positive value means that the surface bends towards the image plane, and a negative value means that the surface bends towards the object plane. "INF" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the central axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space represents that the current position is air and the refractive index is 1.

[0083] Table 3 shows the aspheric coefficient values ​​used in the current embodiment.

[0084] Table 3. Design values ​​for the aspherical coefficient of industrial lenses.

[0085]

[0086] The K values ​​in Table 2 represent the numerical values ​​of the best-fit conic coefficients for the aspheric surface. The conic coefficients of the aspheric surface can be defined using the following aspheric formula, but are not limited to the following representations:

[0087]

[0088] Where z is the axial sagitta in the Z direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature; k is the coefficient of the fitted cone; and AG are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th and 16th orders of the aspherical polynomial.

[0089] In the table above, 5.9406E-05 represents 5.9406 × 10⁻⁵. -5 All other coefficients are represented in this way.

[0090] Furthermore, Figure 2 This is a schematic diagram of axial aberration of an industrial lens provided in Embodiment 1 of the present invention. The vertical direction represents the normalized aperture, 0 indicates that it is on the optical axis, and the vertical vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focal point, in millimeters (mm). Different linear curves in the figure represent different wavelengths of system imaging (specifically 450nm, 480nm, 500nm, 550nm, 600nm, and 650nm), which are... Figure 2 It can be seen that the axial aberrations at different wavelengths are all controlled within a reasonable range, indicating that the axial aberrations of this industrial lens at each wavelength are well controlled and can meet the requirements of wide spectrum applications.

[0091] Figure 3 This is a schematic diagram of the transverse chromatic aberration of an industrial lens provided in Embodiment 1 of the present invention. The vertical direction represents the normalization of the field of view, and 0 indicates that it is on the optical axis. The dominant wavelength is 546nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 3 As can be seen, the transverse chromatic aberration at different wavelengths (specifically 450nm, 480nm, 500nm, 550nm, 600nm and 650nm) is controlled within a good range, indicating that the transverse chromatic aberration of this industrial lens is well controlled in industrial applications and can meet the requirements of wide spectrum applications.

[0092] Figure 4 This is a schematic diagram of field curvature distortion of an industrial lens provided in Embodiment 1 of the present invention. In the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature, in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; Figure 4 As can be seen, the lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small, resulting in good consistency. In the coordinate system on the right, the horizontal axis represents the magnitude of distortion, expressed as a percentage (%), while the vertical axis represents the normalized image height, which has no unit. Figure 4 As can be seen, the distortion of the lens provided in this embodiment has been well corrected, with optical distortion less than ±0.4%.

[0093] In summary, the industrial lens provided in this embodiment of the invention adopts an all-glass 9G structure. Through the combination of lens materials and the reasonable allocation of the optical power and surface shape of each component, it achieves the characteristics of distortion less than 0.58% and low chromatic aberration while maintaining a sufficiently large field of view. The lens meets the requirements of sufficient detection range and accuracy even at a shooting distance of 50CM.

[0094] Example 2

[0095] Figure 5 This is a schematic diagram of the structure of an industrial lens provided in Embodiment 2 of the present invention, as shown below. Figure 5 As shown, the industrial lens provided in Embodiment 2 of the present invention includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106, a seventh lens 107, an eighth lens 108, and a ninth lens 109 arranged sequentially from the object plane to the image plane. The first lens 101, fifth lens 105, seventh lens 107, and ninth lens 109 are positive power lenses; the third lens 103, fourth lens 104, and sixth lens 106 are negative power lenses; the second lens 102 is either a positive power lens or a negative power lens, and the eighth lens 108 is either a positive power lens or a negative power lens. The first lens 101 includes a first object-side surface near the object plane and a first image-side surface near the image plane, the first object-side surface being convex and the first image-side surface being concave. The second lens 102 includes a second object-side surface near the object plane and a second image-side surface near the image plane. The second object-side surface is convex, and the second image-side surface is concave; the third lens 103 includes a third object-side surface near the object surface and a third image-side surface near the image surface, the third object-side surface being convex and the third image-side surface being concave; the fourth lens 104 includes a fourth object-side surface near the object surface and a fourth image-side surface near the image surface, the fourth object-side surface being convex and the fourth image-side surface being concave; the fifth lens 105 includes a fifth object-side surface near the object surface, the fifth object-side surface being convex; the sixth lens 106 includes a sixth image-side surface near the image surface, the sixth image-side surface being concave; the seventh lens 107 includes a seventh object-side surface near the object surface, the seventh object-side surface being convex; the eighth lens 108 includes an eighth image-side surface near the image surface, the eighth image-side surface being convex; the ninth lens 109 includes a ninth object-side surface near the object surface and a ninth image-side surface near the image surface, the ninth object-side surface being convex and the ninth image-side surface being convex.

[0096] The difference between Example 2 and Example 1 lies in the bonding method of the lens and some optical parameters. Other parameters are the same as in Example 1, and will not be repeated here.

[0097] As another feasible implementation method, the specific parameters in industrial lenses are explained below.

[0098] Table 4. Optical design values ​​for an industrial lens in Example 2

[0099]

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

[0101]

[0102] The surface numbers in Table 5 are assigned according to the surface sequence of each lens. "STO" represents the aperture stop of the lens. The radius of curvature represents the curvature of the corresponding lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "INF" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the central axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1.

[0103] Table 6 shows some specific parameters implemented in this embodiment.

[0104] Table 6 Specific parameters for this embodiment

[0105]

[0106] Furthermore, Figure 6 This is a schematic diagram of axial aberration of an industrial lens provided in Embodiment 2 of the present invention. The vertical direction represents the normalized aperture, 0 indicates that it is on the optical axis, and the vertical vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Different linear curves in the figure represent different wavelengths of system imaging (specifically 450nm, 480nm, 500nm, 550nm, 600nm, and 650nm), which are determined by... Figure 6 It can be seen that the axial aberrations at different wavelengths are all controlled within a reasonable range, indicating that the axial aberrations of this industrial lens at each wavelength are well controlled and can meet the requirements of wide spectrum applications.

[0107] Figure 7 This is a schematic diagram of the transverse chromatic aberration of an industrial lens provided in Embodiment 2 of the present invention. The vertical direction represents the normalization of the field of view, and 0 indicates that it is on the optical axis. The dominant wavelength is 546nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 7 As can be seen, the transverse chromatic aberration at different wavelengths (specifically 450nm, 480nm, 500nm, 550nm, 600nm and 650nm) is controlled within a good range, indicating that the transverse chromatic aberration of this industrial lens is well controlled in industrial applications and can meet the requirements of wide spectrum applications.

[0108] Figure 8 This is a schematic diagram of field curvature distortion of an industrial lens provided in Embodiment 2 of the present invention. In the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature, in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; Figure 8As can be seen, the lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small, resulting in good consistency. In the coordinate system on the right, the horizontal axis represents the magnitude of distortion, expressed as a percentage (%), while the vertical axis represents the normalized image height, which has no unit. Figure 8 As can be seen, the distortion of the lens provided in this embodiment has been well corrected, with optical distortion less than ±0.8%.

[0109] In summary, the industrial lens provided in this embodiment of the invention adopts an all-glass 9G structure. Through the combination of lens materials and the reasonable allocation of the optical power and surface shape of each component, it achieves the characteristics of distortion less than 0.58% and low chromatic aberration while maintaining a sufficiently large field of view. The lens meets the requirements of sufficient detection range and accuracy even at a shooting distance of 50CM.

[0110] Example 3

[0111] Figure 9 This is a schematic diagram of the structure of an industrial lens provided in Embodiment 3 of the present invention, as shown below. Figure 9As shown, the industrial lens provided in Embodiment 3 of the present invention includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106, a seventh lens 107, an eighth lens 108, and a ninth lens 109 arranged sequentially from the object plane to the image plane. The first lens 101, fifth lens 105, seventh lens 107, and ninth lens 109 are positive power lenses; the third lens 103, fourth lens 104, and sixth lens 106 are negative power lenses; the second lens 102 is either a positive power lens or a negative power lens, and the eighth lens 108 is either a positive power lens or a negative power lens. The first lens 101 includes a first object-side surface near the object plane and a first image-side surface near the image plane, the first object-side surface being convex and the first image-side surface being concave. The second lens 102 includes a second object-side surface near the object plane and a second image-side surface near the image plane. The second object-side surface is convex, and the second image-side surface is concave; the third lens 103 includes a third object-side surface near the object surface and a third image-side surface near the image surface, the third object-side surface being convex and the third image-side surface being concave; the fourth lens 104 includes a fourth object-side surface near the object surface and a fourth image-side surface near the image surface, the fourth object-side surface being convex and the fourth image-side surface being concave; the fifth lens 105 includes a fifth object-side surface near the object surface, the fifth object-side surface being convex; the sixth lens 106 includes a sixth image-side surface near the image surface, the sixth image-side surface being concave; the seventh lens 107 includes a seventh object-side surface near the object surface, the seventh object-side surface being convex; the eighth lens 108 includes an eighth image-side surface near the image surface, the eighth image-side surface being convex; the ninth lens 109 includes a ninth object-side surface near the object surface and a ninth image-side surface near the image surface, the ninth object-side surface being convex and the ninth image-side surface being convex.

[0112] The difference between Example 3 and Example 1 lies in some optical parameters, while the other parameters are the same as in Example 1, and will not be repeated here.

[0113] As another feasible implementation method, the specific parameters in industrial lenses are explained below.

[0114] Table 7. Optical design values ​​for a fixed-focus lens in Example 3

[0115]

[0116] Table 8 Optical Design Values ​​of Various Lenses in Industrial Lenses

[0117]

[0118] The surface numbers in Table 8 are assigned according to the surface sequence of each lens. "STO" represents the aperture stop of the lens. The radius of curvature represents the curvature of the corresponding lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "INF" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the central axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1.

[0119] Table 9 shows some specific parameters implemented in this embodiment.

[0120] Table 9 Specific parameters for this embodiment

[0121]

[0122] Furthermore, Figure 10 This is a schematic diagram of axial aberration of an industrial lens provided in Embodiment 3 of the present invention. The vertical direction represents the normalized aperture, 0 indicates that it is on the optical axis, and the vertical vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). The different linear curves in the figure represent different wavelengths of system imaging (specifically 450nm, 480nm, 500nm, 550nm, 600nm, and 650nm), which are determined by... Figure 10 It can be seen that the axial aberrations at different wavelengths are all controlled within a reasonable range, indicating that the axial aberrations of this industrial lens at each wavelength are well controlled and can meet the requirements of wide spectrum applications.

[0123] Figure 11 This is a schematic diagram of the transverse chromatic aberration of an industrial lens provided in Embodiment 3 of the present invention. The vertical direction represents the normalization of the field of view, and 0 indicates that it is on the optical axis. The dominant wavelength is 546nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 11 As can be seen, the transverse chromatic aberration at different wavelengths (specifically 450nm, 480nm, 500nm, 550nm, 600nm and 650nm) is controlled within a good range, indicating that the transverse chromatic aberration of this industrial lens is well controlled in industrial applications and can meet the requirements of wide spectrum applications.

[0124] Figure 12 This is a schematic diagram of field curvature distortion of an industrial lens provided in Embodiment 3 of the present invention. In the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature, in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; Figure 12As can be seen, the lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small, resulting in good consistency. In the coordinate system on the right, the horizontal axis represents the magnitude of distortion, expressed as a percentage (%), while the vertical axis represents the normalized image height, which has no unit. Figure 12 As can be seen, the distortion of the lens provided in this embodiment has been well corrected, with optical distortion less than ±0.6%.

[0125] In summary, the industrial lens provided in this embodiment of the invention adopts an all-glass 9G structure. Through the combination of lens materials and the reasonable allocation of the optical power and surface shape of each component, it achieves the characteristics of distortion less than 0.58% and low chromatic aberration while maintaining a sufficiently large field of view. The lens meets the requirements of sufficient detection range and accuracy even at a shooting distance of 50CM.

[0126] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An industrial lens, characterized in that, It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially along the optical axis from the object plane to the image plane; the first lens, the fifth lens, the seventh lens, and the ninth lens are positive power lenses; the third lens, the fourth lens, and the sixth lens are negative power lenses; the second lens is either a positive power lens or a negative power lens; and the eighth lens is either a positive power lens or a negative power lens. The first lens includes a first object-side surface near the object plane and a first image-side surface near the image plane. The first object-side surface is convex, and the first image-side surface is concave. The second lens includes a second object-side surface near the object plane and a second image-side surface near the image plane, wherein the second object-side surface is convex and the second image-side surface is concave. The third lens includes a third object-side surface near the object plane and a third image-side surface near the image plane. The third object-side surface is convex, and the third image-side surface is concave. The fourth lens includes a fourth object-side surface near the object plane and a fourth image-side surface near the image plane. The fourth object-side surface is convex, and the fourth image-side surface is concave. The fifth lens includes a fifth object-side surface near the object surface, and the fifth object-side surface is a convex surface; The sixth lens includes a sixth image side surface near the image plane, and the sixth image side surface is concave. The seventh lens includes a seventh object-side surface near the object surface, and the seventh object-side surface is convex. The eighth lens includes an eighth image side surface near the image plane, and the eighth image side surface is convex. The ninth lens includes a ninth object-side surface near the object plane and a ninth image-side surface near the image plane. The ninth object-side surface is convex, and the ninth image-side surface is convex.

2. The industrial lens according to claim 1, characterized in that, The fifth lens also includes a fifth image-side surface near the image plane, which is either convex or concave. The sixth lens also includes a sixth object-side surface near the object surface, which is either convex or concave. The seventh lens also includes a seventh image side surface near the image plane, which is either convex or concave. The eighth lens also includes an eighth object-side surface near the object surface, which is either convex or concave.

3. The industrial lens according to claim 2, characterized in that, The focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, the focal length of the eighth lens is f8, the focal length of the ninth lens is f9, and the focal length of the industrial lens is f. Among them, 4.19 <f1 / f<5.70,-1.49<f2 / f<13.32,-1.50<f3 / f<-1.23,-1.23<f4 / f<-0.66,0.64<f5 / f<1.10,-3.34<f6 / f<-1.00,0.96<f7 / f<1.45,-1.86<f8 / f<1.71,1.65<f9 / f<1.88。 4. The industrial lens according to claim 1, characterized in that, The first lens has a refractive index of Nd1 and an Abbe number of Vd1; the second lens has a refractive index of Nd2 and an Abbe number of Vd2; the third lens has a refractive index of Nd3 and an Abbe number of Vd3; the fourth lens has a refractive index of Nd4 and an Abbe number of Vd4; the fifth lens has a refractive index of Nd5 and an Abbe number of Vd5; the sixth lens has a refractive index of Nd6 and an Abbe number of Vd6; the seventh lens has a refractive index of Nd7 and an Abbe number of Vd7; the eighth lens has a refractive index of Nd8 and an Abbe number of Vd8; and the ninth lens has a refractive index of Nd9 and an Abbe number of Vd9. Among them, 1.63≤Nd1≤1.91, 35≤Vd1≤73; 1.78≤Nd2≤2, 18≤Vd2≤37; 1.56≤Nd3≤1.75, 50≤Vd3≤75; 1.45≤Nd4≤1.62, 50≤Vd4≤97; 2≤Nd5≤2.01, 24.9≤Vd5≤35; 1.86≤Nd6≤1.96, 15.3≤Vd6≤24.8; 1.6≤Nd7≤2.05, 17≤Vd7≤58; 1.55≤Nd8≤1.75, 20.2≤Vd8≤80; 1.95≤Nd9≤2.02, 19.7≤Vd9≤25.

5.

5. The industrial lens according to claim 1, characterized in that, The industrial lens has a maximum field of view (FOV) and an aperture number (FNO). Among them, 12.22≤FOV / FNO≤12.

39.

6. The industrial lens according to claim 1, characterized in that, The distortion of the industrial lens is Dis; Among them, 0.28%≤|Dis|≤0.58%.

7. The industrial lens according to claim 1, characterized in that, The industrial lens has a back focal length of BFL and a total length of TTL. Wherein, 0.171≤BEL / TTL≤0.

192.

8. The industrial lens according to claim 1, characterized in that, The fifth lens and the sixth lens are cemented together, and the seventh lens and the eighth lens are cemented together; Alternatively, the sixth lens and the seventh lens may be cemented together.

9. The industrial lens according to claim 1, characterized in that, The first lens, the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens are all glass spherical lenses; The fourth lens is a glass spherical lens or a glass aspherical lens.

10. The industrial lens according to claim 1, characterized in that, The industrial lens also includes an aperture stop, which is disposed in the optical path between the fifth lens and the sixth lens; Alternatively, the aperture may be positioned in the optical path between the sixth lens and the seventh lens.

Images