Industrial lens
By combining the optical power of seven lenses and designing a reasonable focal length, the problems of distortion and single-band operation in industrial lenses are solved, achieving high-precision imaging with low distortion and applicability to different bands, which is suitable for the miniaturization design of industrial lenses.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-07
AI Technical Summary
Existing industrial lenses suffer from poor distortion control, resulting in low scanning accuracy and limited spectral bands, despite the need for large scanning ranges and fine imaging details.
Design an industrial lens that uses a combination of seven lenses with varying optical power, including positive and negative optical power lenses. Optical focal lengths and aperture positions are rationally set. Glass spherical lenses are used, and cemented lens technology is employed to reduce chromatic aberration and light loss. This lens is suitable for optical systems operating in different wavelength bands.
It achieves imaging effects with low distortion and applicability to different wavelengths, improving scanning accuracy and imaging quality. At the same time, the lens is miniaturized and suitable for wavelengths around 450nm and 850nm.
Smart Images
Figure CN121806244A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The embodiment of the present application relates to the technical field of optical devices, in particular to an industrial lens. BACKGROUND
[0002] In recent years, with the development of industrial automation, the market demand for lenses with large scanning range and high imaging quality has greatly increased. However, the lenses on the market have defects such as low scanning accuracy and single waveband. SUMMARY
[0003] The present application provides an industrial lens, which realizes small distortion, different wavebands and good imaging effect.
[0004] The embodiment of the present application provides an industrial lens, which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along an optical axis from an object plane to an image plane.
[0005] The first lens, the fourth lens and the seventh lens are positive focal length lenses; the second lens is a negative focal length lens; the third lens is a positive focal length lens or a negative focal length lens; the fifth lens is a positive focal length lens or a negative focal length lens, and the sixth lens is a positive focal length lens or a negative focal length lens.
[0006] 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, and the focal length of the industrial lens is f.
[0007] Wherein, 7.653 < f1 / f < 8.53, -1.178 < f2 / f < -1.106, -1.512 < f3 / f < 2.528, 1.084 < f4 / f < 1.952, -29.197 < f5 / f < 1.768, -1.079 < f6 / f < 2.833, 1.406 < f7 / f < 3.866.
[0008] Optionally, the industrial lens further comprises a diaphragm.
[0009] The third lens is a positive focal length lens, and the diaphragm is arranged in the optical path between the third lens and the fourth lens.
[0010] Alternatively, the diaphragm is arranged in the optical path between the fourth lens and the fifth lens.
[0011] Optionally, the first lens comprises a first object-side surface close to the object plane and a first image-side surface close to the image plane, the first object-side surface is convex, and the first image-side surface is concave.
[0012] The second lens comprises a second object-side surface close to the object plane and a second image-side surface close to the image plane, the second object-side surface is convex, and the second image-side surface is concave.
[0013] The third lens comprises a third object-side surface close to the object plane and a third image-side surface close to the image plane, the third object-side surface is convex or concave, and the third image-side surface is convex or concave.
[0014] The fourth lens comprises a fourth object-side surface close to the object plane and a fourth image-side surface close to the image plane, the fourth object-side surface is convex, and the fourth image-side surface is convex or concave.
[0015] The fifth lens comprises a fifth object-side surface close to the object plane and a fifth image-side surface close to the image plane, the fifth object-side surface is convex, and the fifth image-side surface is convex or concave.
[0016] The sixth lens comprises a sixth object-side surface close to the object plane and a sixth image-side surface close to the image plane, the sixth object-side surface is convex or concave, and the sixth image-side surface is convex or concave.
[0017] The seventh lens comprises a seventh object-side surface close to the object plane and a seventh image-side surface close to the image plane, the seventh object-side surface is convex or concave, and the seventh image-side surface is convex or concave.
[0018] Optionally, the first lens has a refractive index Nd1 and an Abbe number Vd1, the second lens has a refractive index Nd1 and an Abbe number Vd2, the third lens has a refractive index Nd3 and an Abbe number Vd3, the fourth lens has a refractive index Nd4 and an Abbe number Vd4, the fifth lens has a refractive index Nd5 and an Abbe number Vd5, the sixth lens has a refractive index Nd6 and an Abbe number Vd6, and the seventh lens has a refractive index Nd7 and an Abbe number Vd7.
[0019] Wherein, 1.69≤Nd1≤1.76, 47≤Vd1≤80; 1.73≤Nd2≤1.79, 49.2≤Vd2≤80; 1.72≤Nd3≤1.81, 39.9≤Vd3≤70; 1.5≤Nd4≤1.63, 26.8≤Vd4≤90; 1.69≤Nd5≤1.87, 18.5≤Vd5≤30.1; 1.7≤Nd6≤1.8, 23.2≤Vd6≤58.6; 1.75≤Nd7≤1.9, 22.9≤Vd7≤45.
[0020] Optionally, the maximum field angle of the industrial lens is FOV, and the F-number is FNO.
[0021] Wherein, FOV / FNO≤19.85.
[0022] Optionally, the back focal length of the industrial lens is BFL, and the total optical length is TTL.
[0023] Wherein, BEL / TTL≥0.301.
[0024] Optionally, the fifth lens and the sixth lens are cemented.
[0025] Optionally, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all glass spherical lenses.
[0026] Optionally, the distortion of the industrial lens is Dis.
[0027] Wherein, |Dis|≤2.74%.
[0028] Optionally, the applicable wavelength λ of the industrial lens satisfies 430nm≤λ≤470nm and 840nm≤λ≤860nm.
[0029] The industrial lens provided by the embodiment of the present application can guarantee the total length of the industrial lens by reasonably setting the number of lenses, realize the design of relatively small size of the industrial lens while guaranteeing small imaging aberration and high imaging quality, and further correct aberration and distortion by reasonably matching the power design mode of seven lenses and the specific focal length parameters, so that the industrial lens design with small distortion and applicable to different wave bands is realized.
[0030] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS
[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.
[0032] Figure 1 is a structural schematic diagram of an industrial lens provided by the first embodiment of the present application;
[0033] Figure 2 is a light ray light fan schematic diagram of the industrial lens provided by the first embodiment of the present application;
[0034] Figure 3 is another light ray light fan schematic diagram of the industrial lens provided by the first embodiment of the present application;
[0035] Figure 4 is a field curvature distortion schematic diagram of the industrial lens provided by the first embodiment of the present application;
[0036] Figure 5 is another field curvature distortion schematic diagram of the industrial lens provided by the first embodiment of the present application;
[0037] Figure 6 is a vertical axis chromatic aberration schematic diagram of the industrial lens provided by the first embodiment of the present application;
[0038] Figure 7 is another vertical axis chromatic aberration schematic diagram of the industrial lens provided by the first embodiment of the present application;
[0039] Figure 8 is a structural schematic diagram of an industrial lens provided by the second embodiment of the present application;
[0040] Figure 9 is a light ray light fan schematic diagram of the industrial lens provided by the second embodiment of the present application;
[0041] Figure 10 is another light ray light fan schematic diagram of the industrial lens provided by the second embodiment of the present application;
[0042] Figure 11 is a field curvature distortion schematic diagram of the industrial lens provided by the second embodiment of the present application;
[0043] Figure 12 is another field curvature distortion schematic diagram of the industrial lens provided by the second embodiment of the present application;
[0044] Figure 13 is a vertical axis chromatic aberration schematic diagram of the industrial lens provided by the second embodiment of the present application;
[0045] Figure 14is another vertical color aberration diagram of an industrial lens provided by the second embodiment of the present application;
[0046] Figure 15 is a structural diagram of an industrial lens provided by the third embodiment of the present application;
[0047] Figure 16 is a light ray light fan diagram of an industrial lens provided by the third embodiment of the present application;
[0048] Figure 17 is another light ray light fan diagram of an industrial lens provided by the third embodiment of the present application;
[0049] Figure 18 is a field curvature distortion diagram of an industrial lens provided by the third embodiment of the present application;
[0050] Figure 19 is another field curvature distortion diagram of an industrial lens provided by the third embodiment of the present application;
[0051] Figure 20 is a vertical color aberration diagram of an industrial lens provided by the third embodiment of the present application;
[0052] Figure 21 is another vertical color aberration diagram of an industrial lens provided by the third embodiment of the present application. DETAILED DESCRIPTION
[0053] In order to make the personnel in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by the person of ordinary skill in the art without creative labor should belong to the scope of protection of the present application.
[0054] Embodiment one
[0055] Figure 1 is a structural diagram of an industrial lens provided by the first embodiment of the present application, as shown in 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, and a seventh lens 107 arranged sequentially along the optical axis from the object plane to the image plane; the first lens 101, the fourth lens 104, and the seventh lens 107 are all positive power lenses; the second lens 102 is a negative power lens; the third lens 103 is either a positive power lens or a negative power lens; the fifth lens 106... Lens 105 is either a positive or negative power lens, and the sixth lens 106 is either a positive or negative power lens; the focal length of the first lens 101 is f1, the second lens 102 is f2, the third lens 103 is f3, the fourth lens 104 is f4, the fifth lens 105 is f5, the sixth lens 106 is f6, the seventh lens 107 is f7, and the focal length of the industrial lens is f; among which, 7.653 <f1 / f<8.53,-1.178<f2 / f<-1.106,-1.512<f3 / f<2.528,1.084<f4 / f<1.952,-29.197<f5 / f<1.768,-1.079<f6 / f<2.833,1.406<f7 / f<3.866。
[0056] like Figure 1 As shown, the industrial lens provided in this embodiment of the invention includes seven lenses with optical power. The arrangement of seven lenses with optical power ensures that the number of lenses in the industrial lens is reasonable. Too many lenses will result in a large lens size, and too few lenses will result in a large aberration due to a single lens bearing a large optical power. This ensures that the industrial lens is miniaturized while ensuring small imaging aberrations and high imaging quality.
[0057] Further, the optical power is equal to the difference between the converging degree of the image plane and the converging degree of the object plane, which represents the ability of the optical system to deflect light. The greater the absolute value of the optical power, the stronger the bending ability of the light, and the smaller the absolute value of the optical power, the weaker the bending ability of the light. When the optical power is positive, the refraction of the light is convergent; when the optical power is negative, the refraction of the light is divergent. The optical power can be used to represent a certain refractive surface of a lens (i.e., a surface of the lens), a certain lens, or a system formed by multiple lenses (i.e., a lens group). In the embodiment of the application, the first lens 101 is a positive optical power lens, which can collect light for large-aperture light rays of the industrial lens, so that the light rays of large angles can smoothly enter the optical system, effectively controlling the length and aperture of the industrial lens, and being conducive to the design of small size and light weight. The second lens 102 is a negative optical power lens, which adjusts the incident light as the first lens in the industrial lens. The negative optical power of the second lens 102 can ensure that the light has a larger aperture before entering the diaphragm, increase the aperture of the industrial lens, and enable the lens to clearly image in dim or dark conditions. Further, the third lens 103 is a positive optical power lens or a negative optical power lens. When the third lens 103 is a negative optical power lens, the third lens 103 can adjust the incident light together with the second lens 102. The negative optical power of the third lens 103 can ensure that the light has a larger aperture before entering the diaphragm, increase the aperture of the industrial lens, and enable the lens to clearly image in dim or dark conditions. When the third lens 103 is a positive optical power lens, the third lens 103 can correct the large aberration generated by the second lens 102 in time, especially the edge aberration of the industrial lens, thereby improving the imaging resolution of the optical system. Further, the fifth lens 105 is a positive optical power lens or a negative optical power lens, the sixth lens 106 is a positive optical power lens or a negative optical power lens, and the optical power of the fifth lens 105 is matched with the optical power of the sixth lens 106, and the optical power of the fifth lens 105 is matched with the optical power of the front four lenses. The optical power of the fifth lens 105 can further adjust the light path and correct the large aberration in time, especially the edge aberration of the industrial lens, thereby improving the imaging resolution of the optical system. Further, the seventh lens 107 is the last lens with optical power in front of the image plane. The positive optical power of the seventh lens 107 can correct the aberration such as field curvature and astigmatism to improve the imaging quality, and can also shorten the back focal distance of the industrial lens to realize the miniaturization of the industrial lens.
[0058] Further, the focal length f1 of the first lens 101, the focal length f2 of the second lens 102, the focal length f3 of the third lens 103, the focal length f4 of the fourth lens 104, the focal length f5 of the fifth lens 105, the focal length f6 of the sixth lens 106, the focal length f7 of the seventh lens 107, and the focal length f of the industrial lens satisfy 7.653 < f1 / f < 8.53, -1.178 < f2 / f < -1.106, -1.512 < f3 / f < 2.528, 1.084 < f4 / f < 1.952, -29.197 < f5 / f < 1.768, -1.079 < f6 / f < 2.833, 1.406 < f7 / f < 3.866, by reasonable distribution of the focal length of the lens, the aberration of the whole optical system can be effectively reduced, the balance of the incident angle of the front and rear lenses is ensured, the sensitivity of the lens is reduced, and the distortion is reduced. Moreover, the distribution of the focal length of the lens at the front end of the stop can make the light pass through the stop smoothly, reduce the high-order aberration generated near the stop, and further balance the aberration of the optical system, thereby improving the imaging quality of the optical system.
[0059] In summary, the industrial lens provided by the embodiment of the present application includes seven lenses with optical power, and the number of lenses is reasonably set to ensure that the total length of the industrial lens is appropriate, and the industrial lens is relatively small in size while ensuring small imaging aberration and high imaging quality. Further, the optical power of the seven lenses is arranged in the form of positive-negative-positive / positive-positive-positive / negative-positive / positive-positive, and the optical power of the seven lenses is reasonably arranged to increase the aperture of the industrial lens and correct aberration and distortion, thereby improving the imaging resolution of the industrial lens.
[0060] Moreover, the industrial lens provided by the embodiment of the present application can be applied to different wave bands, specifically, the applicable wavelength λ of the industrial lens satisfies 430nm ≤ λ ≤ 470nm and 840nm ≤ λ ≤ 860nm, that is, the optical system can be applied to a wave band of about 450nm and a wave band of about 850nm, and has good imaging effect in the two wave band ranges.
[0061] On the basis of the above embodiment, the industrial lens further includes a stop STO, the third lens 103 is a positive power lens, and the stop STO is arranged in the optical path between the third lens 103 and the fourth lens 104, or the stop STO is arranged in the optical path between the fourth lens 104 and the fifth lens 105.
[0062] Specifically, the diaphragm STO is arranged to adjust the propagation direction of the light beam, which is conducive to improving the imaging quality, and the diaphragm STO is arranged at the middle of the industrial lens to minimize the front and back apertures of the industrial lens. Further, when the third lens 103 is a positive lens, the diaphragm STO can be arranged between the third lens 103 and the fourth lens 104; or when the third lens 103 is a negative lens, the diaphragm STO can be arranged between the fourth lens 104 and the fifth lens 105. That is, the diaphragm STO is arranged at different positions for different combinations of lens focal lengths, which can effectively increase the aperture size of the optical system and achieve a large aperture. In addition, the diaphragm position is different for different lens focal length distributions, which can also reduce the high-order aberrations generated near the diaphragm STO of the optical system, further improving the imaging quality of the optical system.
[0063] Further, the industrial lens provided by the embodiment of the present application can further include a filter 108, a protective glass and an imaging sensor (not shown in the figure). The filter 108 is arranged in the light path between the seventh lens 107 and the image plane. The protective glass can be arranged on the image side of the filter. The imaging sensor can be arranged on the image side of the protective glass. The filter 108 can filter out stray light spectrum to ensure the imaging quality. The protective glass can protect the optical system. The imaging sensor can collect images to realize the normal imaging function of the optical system.
[0064] On the basis of the above-mentioned embodiment, the first lens 101 includes a first object side surface close to the object plane and a first image side surface close to the image plane. The first object side surface is convex, and the first image side surface is concave. The second lens 102 includes a second object side surface close to the object plane and a second image side surface close to 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 close to the object plane and a third image side surface close to the image plane. The third object side surface is convex or concave, and the third image side surface is convex or concave. The fourth lens 104 includes a fourth object side surface close to the object plane and a fourth image side surface close to the image plane. The fourth object side surface is convex, and the fourth image side surface is convex or concave. The fifth lens 105 includes a fifth object side surface close to the object plane and a fifth image side surface close to the image plane. The fifth object side surface is convex, and the fifth image side surface is convex or concave. The sixth lens 106 includes a sixth object side surface close to the object plane and a sixth image side surface close to the image plane. The sixth object side surface is convex or concave, and the sixth image side surface is convex or concave. The seventh lens 107 includes a seventh object side surface close to the object plane and a seventh image side surface close to the image plane. The seventh object side surface is convex or concave, and the seventh image side surface is convex or concave.
[0065] Specifically, the object side of the lens can be understood as the surface of the lens close to the object plane, and the image side of the lens can be understood as the surface of the lens close to the image plane.
[0066] The object side of the first lens 101 is a convex surface, and the image side is a concave surface, which can be understood as the object side of the first lens 101 protruding towards the object plane at the position near the optical axis, and the image side is concave towards the image plane at the position near the optical axis, that is, the first lens 101 is a convex-concave structure lens.
[0067] The object side of the second lens 102 is a convex surface, and the image side is a concave surface, which can be understood as the object side of the second lens 102 protruding towards the object plane at the position near the optical axis, and the image side is concave towards the image plane at the position near the optical axis, that is, the second lens 102 is a convex-concave structure lens.
[0068] The object side of the third lens 103 is a convex surface or a concave surface, and the image side is a convex surface or a concave surface, which can be understood as the object side of the third lens 103 protruding towards the object plane or concave at the position near the optical axis, and the image side is convex or concave towards the image plane at the position near the optical axis, that is, the third lens 103 is a double-convex structure, convex-concave structure, double-concave structure or concave-convex structure lens.
[0069] The object side of the fourth lens 104 is a convex surface, and the image side is a convex surface or a concave surface, which can be understood as the object side of the fourth lens 104 protruding towards the object plane at the position near the optical axis, and the image side is convex or concave towards the image plane at the position near the optical axis, that is, the fourth lens 104 is a double-convex structure or convex-concave structure lens.
[0070] The object side of the fifth lens 105 is a convex surface, and the image side is a convex surface or a concave surface, which can be understood as the object side of the fifth lens 105 protruding towards the object plane at the position near the optical axis, and the image side is convex or concave towards the image plane at the position near the optical axis, that is, the fifth lens 105 is a double-convex structure or convex-concave structure lens.
[0071] The object side of the sixth lens 106 is a convex surface or a concave surface, and the image side is a convex surface or a concave surface, which can be understood as the object side of the sixth lens 106 protruding towards the object plane or concave at the position near the optical axis, and the image side is convex or concave towards the image plane at the position near the optical axis, that is, the sixth lens 103 is a double-convex structure, convex-concave structure, double-concave structure or concave-convex structure lens.
[0072] The object side of the seventh lens 107 is a convex surface or a concave surface, and the image side is a convex surface or a concave surface, which can be understood as the object side of the seventh lens 107 protruding towards the object plane or concave at the position near the optical axis, and the image side is convex or concave towards the image plane at the position near the optical axis, that is, the seventh lens 107 is a double-convex structure, convex-concave structure, double-concave structure or concave-convex structure lens.
[0073] By reasonably setting the concave-convex surface type of each lens, the modulation of the light ray exit angle by each lens can be ensured, and for the cemented lens, the cemented setting of at least two adjacent lenses can be realized, on the other hand, the spacing between adjacent lenses can be reduced, which is beneficial to realize the design of small volume industrial lens.
[0074] On the basis of the above embodiment, the refractive index of the first lens 101 is Nd1, the Abbe number is Vd1; the refractive index of the second lens 102 is Nd1, the Abbe number is Vd2; the refractive index of the third lens 103 is Nd3, the Abbe number is Vd3; the refractive index of the fourth lens 104 is Nd4, the Abbe number is Vd4; the refractive index of the fifth lens 105 is Nd5, the Abbe number is Vd5; the refractive index of the sixth lens 106 is Nd6, the Abbe number is Vd6; the refractive index of the seventh lens is Nd7, the Abbe number is Vd7; wherein 1.69≤Nd1≤1.76, 47≤Vd1≤80; 1.73≤Nd2≤1.79, 49.2≤Vd2≤80; 1.72≤Nd3≤1.81, 39.9≤Vd3≤70; 1.5≤Nd4≤1.63, 26.8≤Vd4≤90; 1.69≤Nd5≤1.87, 18.5≤Vd5≤30.1; 1.7≤Nd6≤1.8, 23.2≤Vd6≤58.6; 1.75≤Nd7≤1.9, 22.9≤Vd7≤45.
[0075] Specifically, the refractive index is the ratio of the propagation speed of light in vacuum to the propagation speed of light in the medium, mainly used to describe the refractive ability of the material to light, and the refractive index of different materials is different. Abbe number is an index used to represent the dispersion ability of transparent medium. The more serious the dispersion of the medium is, the smaller the Abbe number is; on the contrary, the lighter the dispersion of the medium is, the larger the Abbe number is. The present application uses more refractive index materials, which can effectively correct aberration and further meet the high definition required by industrial lens. Using more high refractive index lenses can also reduce the curvature of spherical lenses to reduce the processing difficulty of lenses.
[0076] On the basis of the above embodiment, the numerical value of the maximum field angle of the industrial lens is FOV, and the aperture number is FNO; wherein FOV / FNO≤19.85. By limiting the corresponding relationship between the numerical value FOV of the maximum field angle of the industrial lens and the aperture number FNO of the industrial lens, the optical system can ensure the image quality of the lens with a large field angle under a large enough aperture, and further improve the overall image quality of the optical system. Moreover, limiting the ratio of the maximum field angle FOV of the lens and the aperture number FNO of the lens can further reduce the distortion size of the optical system, and achieve the effect of small distortion required by the industrial lens.
[0077] Specifically, in the embodiment of the present application, the distortion of the industrial lens is Dis; wherein, |Dis|≤2.74%, the distortion is small, which meets the imaging requirement of small distortion and ensures the imaging effect.
[0078] On the basis of the above embodiment, the back focal length of the industrial lens is BFL, and the total optical length is TTL; wherein, BEL / TTL≥0.301. The reasonable selection of the optical back focal length and the total optical length ensures that the industrial lens can meet the focal length requirement while ensuring that the imaging sensor and the flat filter have sufficient installation space, which can ensure that the lens will not interfere with the base and the shell during installation, and ensures that the industrial lens has a simple mounting process.
[0079] On the basis of the above embodiment, the fifth lens 105 and the sixth lens 106 are glued.
[0080] Specifically, the glue between the lenses can be immediately attached to the image side of the previous lens and the object side of the next lens. In the embodiment of the present application, the glued setting of the fifth lens 105 and the sixth lens 106 can be understood as the image side of the fifth lens 105 and the object side of the sixth lens 106. By setting the glued setting of the fifth lens 105 and the sixth lens 106, the air gap between the fifth lens 105 and the sixth lens 106 can be reduced, which helps to reduce the total optical length of the lens, and also reduces the tolerance sensitivity problem such as tilt / offset of the lens unit during assembly process, simplifies the assembly procedure in the lens manufacturing process, and improves the equipment efficiency. At the same time, the glued setting of the fifth lens 105 and the sixth lens 106 can also reduce the light loss caused by reflection between lenses, improve the illumination, and reduce the ghost risk; and the glued lens can be used to minimize chromatic aberration or eliminate chromatic aberration, and the use of glued lens in the industrial lens can improve the image quality and reduce the reflection loss of light energy, thereby improving the image quality and improving the clarity of the lens imaging. Further, the fifth lens 105 and the sixth lens 106 can be supported by a gasket, or can be glued by glue, and the specific gluing method is not limited in the embodiment of the present application.
[0081] On the basis of the above embodiment, the first lens 101, the second lens 02, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, and the seventh lens 107 are all glass spherical lenses.
[0082] Specifically, the spherical lens has a constant curvature from the center of the lens to the periphery of the lens, ensuring that the lens is simple to set. Further, since the glass material has a small thermal expansion coefficient and good stability, the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106 and the seventh lens 107 are all glass spherical lenses, and the thermal properties of the glass spherical lenses are more stable, which can ensure good resolving power of the lens within a wide temperature range when bearing more optical power. Moreover, the glass material has a wider selection range, and the refractive index and Abbe number are relatively free to choose, which can control the high-order aberration and chromatic aberration of the lens to a certain extent, and meet the use requirements under complex conditions.
[0083] As a feasible implementation manner, the parameters of each lens in the industrial lens are described below.
[0084] Table 1: Optical design values of the industrial lens in Example 1
[0085]
[0086] Table 2: Design values of optical physical parameters of the industrial lens
[0087]
[0088] The surface number in Table 2 is numbered according to the surface order of each lens, wherein "1" represents the front surface of the first lens, "2" represents the rear surface of the first lens, and the like; "STO" represents the stop of the lens; "IMA" represents the image surface of the lens; the radius of curvature represents the bending degree of the corresponding lens surface, a positive value represents that the surface is bent towards the image surface, and a negative value represents that the surface is bent towards the object surface, wherein "INF" represents that the surface is a plane, and the radius of curvature is infinite; the thickness represents the center axis distance from the current surface to the next surface; the refractive index represents the deflection ability of the material between the current surface and the next surface; and the space represents that the current position is air, and the refractive index is 1.
[0089] Table 3: Realization of specific parameters in this embodiment
[0090]
[0091] Figure 2 FIG. 1 is a schematic diagram of a light fan of an industrial lens provided by Example 1 of the present application, specifically a schematic diagram of a light fan of a light beam with a wavelength of about 450 nm. Figure 3is another ray fan diagram of an industrial lens provided by embodiment one of the present application, specifically a ray fan diagram of a wavelength of about 850nm. The horizontal axis of the ray fan diagram represents a normalized pupil aperture, and the vertical axis represents the distance of corresponding rays from the chief ray on the image plane. It should be noted that the chief ray is the ray passing through the center of the entrance pupil. In an ideal state, each curve is completely coincident with the horizontal coordinate axis, at which time all rays in the field of view converge to a single point on the image plane. As shown in the figure, the curves of the ray fan diagram of all wavelengths of the field of view are close to the horizontal coordinate, and the curve concentration of each color is high, indicating that the aberration of each field of view of the lens is well corrected, which can ensure clear imaging of the lens in a wide spectral range.
[0092] Figure 4 is a field curvature distortion diagram of an industrial lens provided by embodiment one of the present application, specifically a field curvature distortion diagram of a wavelength of about 450nm. Figure 5 is another field curvature distortion diagram of an industrial lens provided by embodiment one of the present application, specifically a field curvature distortion diagram of a wavelength of about 850nm. As shown in the figure, in the left coordinate system, the horizontal coordinate system represents the size of the field curvature, with units of mm; the vertical coordinate system represents the normalized image height, without units; wherein T represents the meridian, and S represents the sagittal. From Figure 4 and Figure 5 the left coordinate system, it can be seen that the field curvature of the industrial lens provided by embodiment one is effectively controlled for different wavelengths, ensuring that the central image quality and the peripheral image quality are relatively small when imaging. In the right coordinate system, the horizontal coordinate represents the size of the distortion, with units of %; the vertical coordinate represents the normalized image height, without units. From Figure 4 and Figure 5 the right coordinate system, it can be seen that the distortion of the industrial lens provided by embodiment one of the present application is effectively controlled.
[0093] Figure 6 is a vertical axis chromatic aberration diagram of an industrial lens provided by embodiment one of the present application, specifically a vertical axis chromatic aberration diagram of a wavelength of about 450nm. Figure 7 is another vertical axis chromatic aberration diagram of an industrial lens provided by embodiment one of the present application, specifically a vertical axis chromatic aberration diagram of a wavelength of about 850nm. As Figure 6 and Figure 7 shown, the vertical direction represents the normalization of the field of view, and 0 represents on the optical axis; Figure 6 450nm is used as the main wavelength in the middle, Figure 7 850nm is used as the main wavelength in the middle; the horizontal direction represents the offset from the main wavelength, with units of microns (μm), from Figure 6 and Figure 7 it can be seen that the vertical axis chromatic aberration of different wavelengths is controlled in a good range, indicating that the vertical axis chromatic aberration of the industrial lens is well controlled in the industrial end, which can meet the wide spectral application requirements.
[0094] In summary, the embodiment one of the present application provides an industrial lens suitable for two different wave bands, i.e. 450 (±20) nm and 850 (±10) nm. The lens is composed of seven glass ball lenses and a certain thickness of flat glass, which realizes a large enough field angle (φ 9.2 corresponding to a field angle of 80°) and a maximum distortion of less than <2.74%, and has a small chromatic aberration. The lens meets the conditions of sufficient detection range and required accuracy at a shooting distance of 200 mm to infinity.
[0095] Embodiment two
[0096] Figure 8 is a structural schematic diagram of an industrial lens provided by the embodiment two of the present application, as Figure 8 shown, the industrial lens provided by the embodiment two of the present application comprises, in order along the optical axis from the object plane to the image plane, a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106 and a seventh lens 107; the first lens 101, the fourth lens 104 and the seventh lens 107 are positive focal power lenses; the second lens 102 is a negative focal power lens; the third lens 103 is a positive focal power lens or a negative focal power lens; the fifth lens 105 is a positive focal power lens or a negative focal power lens, and the sixth lens 106 is a positive focal power lens or a negative focal power lens; 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, and the focal length of the seventh lens 107 is f7; the focal length of the industrial lens is f; wherein 7.653 < f1 / f < 8.53, -1.178 < f2 / f < -1.106, -1.512 < f3 / f < 2.528, 1.084 < f4 / f < 1.952, -29.197 < f5 / f < 1.768, -1.079 < f6 / f < 2.833, and 1.406 < f7 / f < 3.866.
[0097] Other parameters are the same as those in the embodiment one, which will not be described herein.
[0098] As another possible implementation, the specific parameters in the industrial lens are described as follows.
[0099] Table 4: Optical design values of the industrial lens in the embodiment two
[0100]
[0101] Table 5: Design values of optical physical parameters of the industrial lens
[0102]
[0103] The surface sequence number in Table 5 is numbered according to the surface sequence of each lens, wherein "1" represents the front surface of the first lens, "2" represents the back surface of the first lens, and the like; "STO" represents the diaphragm of the lens; "IMA" represents the image surface of the lens; the radius of curvature represents the bending degree of the corresponding lens surface, a positive value represents that the surface is bent to the image side, and a negative value represents that the surface is bent to the object side, wherein "INF" indicates that the surface is a plane, and the radius of curvature is infinite; the thickness represents the center axis distance from the current surface to the next surface; the refractive index represents the deflection ability of the material between the current surface and the next surface; and the space represents that the current position is air, and the refractive index is 1.
[0104] Table 6: Realization of specific parameters in this embodiment
[0105]
[0106] Figure 9 is a ray fan diagram of an industrial lens provided by Embodiment Two of the present application, specifically a ray fan diagram of a light band of about 450 nm. Figure 10 is another ray fan diagram of an industrial lens provided by Embodiment Two of the present application, specifically a ray fan diagram of a light band of about 850 nm. The horizontal axis of the ray fan diagram represents a normalized pupil aperture, and the vertical axis represents the distance of the corresponding light on the image surface from the chief ray. It should be noted that the chief ray is the light passing through the center of the entrance pupil. In an ideal state, each curve completely coincides with the horizontal coordinate axis, and at this time, all the light in the field of view converges on the same point on the image surface. As shown in the figure, the curves of the ray fan diagrams of all the wavelengths of light in the field of view are close to the horizontal coordinate, and the concentration of the curves of each color is high, which indicates that the aberration of each field of view of the lens is well corrected, and the lens can ensure clear imaging in a wide spectral range.
[0107] Figure 11 is a field curvature distortion diagram of an industrial lens provided by Embodiment Two of the present application, specifically a field curvature distortion diagram of a light band of about 450 nm. Figure 12 is another field curvature distortion diagram of an industrial lens provided by Embodiment Two of the present application, specifically a field curvature distortion diagram of a light band of about 850 nm. As shown in the figure, in the left coordinate system, the horizontal coordinate system represents the size of the field curvature, and the unit is mm; the vertical coordinate system represents the normalized image height, and there is no unit; wherein T represents meridian, and S represents sagittal. From the figure, it can be seen that the field curvature of the lens is very small, and the distortion of the lens is very small, which indicates that the lens has good imaging quality. Figure 11 and Figure 12As can be seen from the left coordinate system, the field curvature of the industrial lens provided in Embodiment Two is effectively controlled for different wavelengths, so that the center image quality and the peripheral image quality are ensured to have a small difference. In the right coordinate system, the horizontal coordinate represents the size of distortion, and the unit is %; the vertical coordinate represents the normalized image height, and there is no unit. As can be seen from the left coordinate system, Figure 11 and Figure 12 As can be seen from the right coordinate system, the distortion of the industrial lens provided in Embodiment Two is effectively controlled.
[0108] Figure 13 is a schematic view of the axial chromatic aberration of an industrial lens provided in Embodiment Two of the present application, and specifically a schematic view of the axial chromatic aberration of a waveband of about 450 nm. Figure 14 is another schematic view of the axial chromatic aberration of an industrial lens provided in Embodiment Two of the present application, and specifically a schematic view of the axial chromatic aberration of a waveband of about 850 nm. As can be seen from Figure 13 and Figure 14 indicated, the vertical direction represents the normalized field of view, and 0 represents on the optical axis; Figure 13 the main wavelength used in the middle is 450 nm, Figure 14 the main wavelength used in the middle is 850 nm; the horizontal direction represents the offset amount relative to the main wavelength, and the unit is micrometers (μm), and as can be seen from Figure 13 and Figure 14 As can be seen, the axial chromatic aberration of different wavelengths is controlled in a good range, which indicates that the axial chromatic aberration of the industrial lens in the industrial end is well controlled, and the wide-spectrum application requirement can be met.
[0109] In summary, Embodiment Two of the present application provides an industrial lens suitable for two different wavebands, i.e., 450 (±20) nm and 850 (±10) nm. The lens is composed of seven glass ball lenses and a certain thickness of flat plate glass, and has a large enough field of view (φ 9.2 corresponds to a field of view of 80°) and | maximum distortion | less than <2.74%, and has the characteristics of small chromatic aberration. The lens meets the conditions of sufficient detection range and required accuracy under a shooting distance of 200 mm to infinity.
[0110] Embodiment Three
[0111] Figure 15 is a schematic view of the structure of an industrial lens provided in Embodiment Three of the present application, as Figure 15As shown, the industrial lens provided by the third embodiment of the present application comprises, in sequence along the optical axis from the object plane to the image plane, a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106 and a seventh lens 107; the first lens 101, the fourth lens 104 and the seventh lens 107 are positive focal length lenses; the second lens 102 is a negative focal length lens; the third lens 103 is a positive focal length lens or a negative focal length lens; the fifth lens 105 is a positive focal length lens or a negative focal length lens, and the sixth lens 106 is a positive focal length lens or a negative focal length lens; 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, and the focal length of the industrial lens is f; wherein 7.653 < f1 / f < 8.53, -1.178 < f2 / f < -1.106, -1.512 < f3 / f < 2.528, 1.084 < f4 / f < 1.952, -29.197 < f5 / f < 1.768, -1.079 < f6 / f < 2.833, and 1.406 < f7 / f < 3.866.
[0112] Other parameters are the same as those in the first embodiment, which will not be repeated here.
[0113] As another possible implementation, the specific parameters in the industrial lens are described below.
[0114] Table 7. One optical design value of the industrial lens in the third embodiment
[0115]
[0116] Table 8. Design value of the optical physical parameters of the industrial lens
[0117]
[0118] The surface number in Table 8 is numbered according to the surface order of each lens, wherein "1" represents the front surface of the first lens, "2" represents the rear surface of the first lens, and so on; "STO" represents the stop of the lens; "IMA" represents the image plane of the lens; the curvature radius represents the bending degree of the corresponding lens surface, a positive value represents that the surface is bent towards the image plane side, and a negative value represents that the surface is bent towards the object plane side, wherein "INF" indicates that the surface is a plane with an infinite curvature radius; the thickness represents the center axis distance from the current surface to the next surface; the refractive index represents the refraction ability of the material between the current surface and the next surface; and the space represents that the current position is empty with a refractive index of 1.
[0119] Table 9. Realization of specific parameters in this embodiment
[0120]
[0121] Figure 16 is a light ray light fan diagram of an industrial lens provided by embodiment three of the present application, specifically a light ray light fan diagram of a wave band of about 450nm. Figure 17 is another light ray light fan diagram of an industrial lens provided by embodiment three of the present application, specifically a light ray light fan diagram of a wave band of about 850nm. The horizontal axis of the light ray light fan diagram represents a normalized pupil aperture, and the vertical axis represents the distance of the corresponding light ray from the chief ray on the image plane. It should be noted that the chief ray is the light ray passing through the center of the entrance pupil. In an ideal state, each curve completely coincides with the horizontal coordinate axis, at which time all light rays in the field of view converge to the same point on the image plane. As shown in the figure, the curves of the light ray light fan diagrams of all wavelengths of the field of view are close to the horizontal coordinate, and the concentration of the curves of each color is high, indicating that the aberration of each field of view of the lens is well corrected, which can ensure clear imaging of the lens in a wide spectral range.
[0122] Figure 18 is a field curvature distortion diagram of an industrial lens provided by embodiment three of the present application, specifically a field curvature distortion diagram of a wave band of about 450nm. Figure 19 is another field curvature distortion diagram of an industrial lens provided by embodiment three of the present application, specifically a field curvature distortion diagram of a wave band of about 850nm. As shown in the figure, in the left coordinate system, the horizontal coordinate system represents the size of the field curvature, with units of mm; the vertical coordinate system represents the normalized image height, without units; wherein T represents the meridian, and S represents the sagittal. From Figure 18 and Figure 19 the left coordinate system, it can be seen that the field curvature of the industrial lens provided by embodiment three is effectively controlled, which ensures that the central image quality and the peripheral image quality are relatively small when imaging. In the right coordinate system, the horizontal coordinate represents the size of the distortion, with units of %; the vertical coordinate represents the normalized image height, without units. From Figure 18 and Figure 19 the right coordinate system, it can be seen that the distortion of the industrial lens provided by embodiment three of the present application is effectively controlled.
[0123] Figure 20 is a vertical axis chromatic aberration diagram of an industrial lens provided by embodiment three of the present application, specifically a vertical axis chromatic aberration diagram of a wave band of about 450nm. Figure 21 is another vertical axis chromatic aberration diagram of an industrial lens provided by embodiment three of the present application, specifically a vertical axis chromatic aberration diagram of a wave band of about 850nm. As Figure 20 and Figure 21 shown, the vertical direction represents the normalization of the field of view, and 0 represents on the optical axis. Figure 20 the main wavelength uses 450nm,Figure 21 The central wavelength uses 850 nm; the horizontal direction represents the offset of the relative central wavelength, and the unit is microns (μm), which is calculated by Figure 20 and Figure 21 It can be seen that the axial chromatic aberration of different wavelengths is controlled in a good range, which shows that the axial chromatic aberration of the industrial lens at the industrial end is well controlled, and the wide-spectrum application requirement can be met.
[0124] In summary, the third embodiment of the present application provides an industrial lens suitable for two different wavebands, i.e., 450 (±20) nm and 850 (±10) nm. The lens is composed of seven glass ball lenses and a certain thickness of flat plate glass, which realizes a large enough field of view (φ 9.2 corresponding to a field of view of 80°) and a maximum distortion of less than <2.74%, and has the characteristics of small chromatic aberration. The lens meets the conditions of sufficient detection range and required accuracy under a shooting distance of 200 mm to infinity.
[0125] The above specific embodiments do not constitute a limitation on the protection scope of the present application. 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 replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.
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, and a seventh lens arranged sequentially along the optical axis from the object plane to the image plane; The first lens, the fourth lens, and the seventh lens are all positive power lenses; the second lens is a negative power lens; the third lens is either a positive power lens or a negative power lens; the fifth lens is either a positive power lens or a negative power lens; and the sixth lens is either a positive power lens or a negative power lens. 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, and the focal length of the industrial lens is f. Among them, 7.653 <f1 / f<8.53,-1.178<f2 / f<-1.106,-1.512<f3 / f<2.528,1.084<f4 / f<1.952,-29.197<f5 / f<1.768,-1.079<f6 / f<2.833,1.406<f7 / f<3.866。 2. The industrial lens according to claim 1, characterized in that, The industrial lens also includes an aperture stop; The third lens is a positive power lens, and the aperture stop is disposed in the optical path between the third lens and the fourth lens; Alternatively, the aperture may be positioned in the optical path between the fourth lens and the fifth lens.
3. The industrial lens according to claim 1, characterized in that, 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 either convex or concave, and the third image-side surface is either convex or 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 either convex or concave. The fifth lens includes a fifth object-side surface near the object plane and a fifth image-side surface near the image plane. The fifth object-side surface is convex, and the fifth image-side surface is either convex or concave. The sixth lens includes a sixth object-side surface near the object plane and a sixth image-side surface near the image plane. The sixth object-side surface is either convex or concave, and the sixth image-side surface is either convex or concave. The seventh lens includes a seventh object-side surface near the object plane and a seventh image-side surface near the image plane. The seventh object-side surface is either convex or concave, and the seventh image-side surface is either convex or concave.
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 Nd1 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; and the seventh lens has a refractive index of Nd7 and an Abbe number of Vd7. Among them, 1.69≤Nd1≤1.76, 47≤Vd1≤80; 1.73≤Nd2≤1.79, 49.2≤Vd2≤80; 1.72≤Nd3≤1.81, 39.9≤Vd3≤70; 1.5≤Nd4≤1.63, 26.8≤Vd4≤90; 1.69≤Nd5≤1.87, 18.5≤Vd5≤30.1; 1.7≤Nd6≤1.8, 23.2≤Vd6≤58.6; 1.75≤Nd7≤1.9, 22.9≤Vd7≤45.
5. The industrial lens according to claim 1, characterized in that, The maximum field of view of the industrial lens is FOV, and the aperture number is FNO; Among them, FOV / FNO≤19.
85.
6. The industrial lens according to claim 1, characterized in that, The industrial lens has a back focal length of BFL and an optical length of TTL. Among them, BEL / TTL≥0.
301.
7. The industrial lens according to claim 1, characterized in that, The fifth lens and the sixth lens are cemented together.
8. The industrial lens according to claim 1, characterized in that, The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all glass spherical lenses.
9. The industrial lens according to claim 1, characterized in that, The distortion of the industrial lens is Dis; Among them, |Dis|≤2.74%.
10. The industrial lens according to claim 1, characterized in that, The applicable wavelength λ of the industrial lens satisfies 430nm≤λ≤470nm and 840nm≤λ≤860nm.