Optical imaging lens

Abstract

The utility model provides an optical imaging lens, which comprises 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 which are sequentially arranged along an optical axis from an object side to an image side, by reasonably distributing the diopter of each lens and optimizing the surface type and the thickness of each lens and the distance between the lenses, the lens can have good imaging quality, so that the problems mentioned in the background technology are solved, three different object distances including the optimized main working distance, the optimized closer working distance and the optimized farther working distance are adopted, and the imaging quality of the lens is improved. The same optical back focus of the same optical path is controlled, and a continuous focusing scheme commonly used in the industry is omitted under the condition that the optical performance requirements of customers are met.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, in particular to an optical imaging lens. Background Art

[0002] Most existing optical lenses have one or more of the following defects:

[0003] First, existing lenses are only designed for infinite object working distance. When the object working distance is close, the lens aberration compatibility is poor and the resolution is low, especially in the edge imaging area, where the resolution drops sharply.

[0004] Second, the existing macro lens is a special lens used for macro photography, which can only be used to shoot very fine objects. The industry generally adjusts a certain lens group to be able to quickly switch from a close-up state to a normal photography state. The structure is relatively complex, and it is cumbersome to use with automated machines, and the accuracy of the photography cannot be guaranteed;

[0005] Third, in order to meet the requirements of micro working distance imaging, existing macro lenses have a large compromise on light transmission (aperture);

[0006] Fourth, existing lenses tend to lose focus when working at high or low temperatures, and fail to solve the problem of lens temperature drift caused by heating of components;

[0007] Fifth, the ghost image energy of existing lenses is large, and the ghost images occupy a large number of pixels. Utility Model Content

[0008] In view of the deficiencies in the prior art, the purpose of the present invention is to provide an optical imaging lens which can provide good imaging quality by reasonably allocating the diopter of each lens and optimizing the surface shape, thickness and distance between lenses of each lens, thereby solving the problems mentioned in the above background technology section.

[0009] The utility model is realized by the following technical solutions:

[0010] An optical imaging lens comprises 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 in sequence along an optical axis from an object side to an image side, wherein:

[0011] The first lens has positive refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a convex surface;

[0012] The second lens has a negative refractive power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface;

[0013] The third lens has a negative refractive power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface;

[0014] The fourth lens has a negative refractive power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a concave surface;

[0015] The fifth lens has positive refractive power, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is convex;

[0016] The sixth lens has positive refractive power, the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface;

[0017] The seventh lens has a negative refractive power, the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface;

[0018] The eighth lens has a negative refractive power, the object side surface of the eighth lens is a convex surface, and the image side surface of the eighth lens is a concave surface;

[0019] The ninth lens element has positive refractive power, the object side surface of the ninth lens element is a convex surface, and the image side surface of the ninth lens element is a convex surface.

[0020] The beneficial effects of this embodiment are: by optimizing the three different object distances of the main working distance, the closer working distance and the farther working distance, the same optical path and the same optical back focus are controlled, and the continuous focusing solution commonly used in the industry is omitted while meeting the customer's optical performance requirements.

[0021] Furthermore, the lens satisfies the following relationship: T1 / D1≥9.5, and R1, R2 are both>0, 10<f1<60, wherein T1 is the center thickness of the first lens, D1 is the outer diameter of the first lens, R1 is the curvature radius of the object side of the first lens, R2 is the curvature radius of the image side of the first lens; and f1 is the focal length of the first lens.

[0022] The beneficial effect of this embodiment is that the above range is satisfied, which is conducive to making the lens meet the close object distance and distortion-free characteristics.

[0023] Furthermore, the lens satisfies the following relationship: -15<f2<-5, -15<f3<-5, -15<f4<-5, wherein f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f4 is the focal length of the fourth lens.

[0024] The beneficial effects of this embodiment are as follows: satisfying the above range is conducive to enabling the lens to meet the requirements of close object distance and wide angle; the second lens, the third lens and the fourth lens use three continuous meniscus compound lenses, which can ensure a large field of view, a large angle and a large aperture ratio for the optical system, and is conducive to compressing the aperture of the optical element to achieve a miniaturized design of the lens.

[0025] Furthermore, the lens satisfies the following relationship: 5<f5<15, wherein f5 is the focal length of the fifth lens.

[0026] The beneficial effects of this embodiment are: satisfying the above range is conducive to balancing the focal length of the lens to ensure a smaller deflection angle, and playing a role in smoothing the transition of light.

[0027] Furthermore, the lens satisfies the following relationship: Nd 6 >1.65,Vd 6 <55,5<f6<15,where Nd 6 is the refractive index of the sixth lens, Vd 6 is the Abbe coefficient of the sixth lens, and f6 is the focal length of the sixth lens.

[0028] Furthermore, the lens satisfies the following relationship: Nd 7 >1.90,Vd 6 <20,-20<f7<-5,where Nd 7 is the refractive index coefficient of the seventh lens, Vd 7 is the Abbe coefficient of the seventh lens; f7 is the focal length of the seventh lens.

[0029] Furthermore, the lens satisfies the following relationship: Nd 8 >1.95,Vd 8 <25,-15<f8<-5,where Nd 8 is the refractive index of the eighth lens, Vd 8 is the Abbe coefficient of the eighth lens, and f8 is the focal length of the eighth lens.

[0030] The beneficial effect of this embodiment is as follows: by satisfying the above range and matching the eighth lens with the ninth lens made of low dispersion material, it is beneficial to correct the secondary chromatic aberration and can effectively improve the imaging quality.

[0031] Furthermore, the lens satisfies the following relationship: Nd 9 <1.6,Vd 9 >65, 5<f9<10, dn / dT<-6.5*10E-6 in the temperature range of -40℃~105℃, where Nd 9 is the refractive index Vd of the ninth lens 9 is the Abbe coefficient of the ninth lens, f9 is the focal length of the ninth lens, and dn / dT is the refractive index temperature coefficient of the material used for the ninth lens.

[0032] The beneficial effect of this embodiment is that the ninth lens is made of a material with a negative refractive index temperature coefficient, which can effectively balance the temperature drift and realize the athermal design of the lens.

[0033] Furthermore, the lens satisfies the following relationship: Vd 9 -Vd 8>40, wherein the eighth lens and the ninth lens are a cemented lens group, Vd 8 is the Abbe coefficient of the eighth lens, Vd 9 is the Abbe coefficient of the ninth lens.

[0034] The beneficial effect of this embodiment is that the eighth lens and the ninth lens adopt a combination of high and low dispersion, which is conducive to correcting secondary chromatic aberration and can effectively improve the imaging quality of the lens.

[0035] Furthermore, a tenth lens is provided on the image side of the ninth lens, the tenth lens has a positive refractive power, the object side surface of the tenth lens is a convex surface, and the image side surface of the tenth lens is a convex surface; the lens satisfies the following relationship: Nd 10 >1.75, where Nd 10 is the refractive index coefficient of the tenth lens.

[0036] The beneficial effects of this embodiment are as follows: the tenth lens is made of a high refractive index material, which is beneficial to improving the resolution of the lens and compressing the diameter of the rear port of the lens.

[0037] Furthermore, the lens satisfies the following relationship: TTL<28.5, BFL≥3.45, wherein TTL is the total length of the lens optical system; BFL is the optical back focus of the lens optical system.

[0038] The beneficial effect of this embodiment is: by satisfying the range of the above formula, the lens has an appropriate back focus, and the appropriate back focus is beneficial to reducing the temperature drift caused by mechanical parts, which can reduce the temperature drift of the entire lens optical system and is beneficial to the athermal design of the lens.

[0039] Furthermore, the lens satisfies the following relationship: D / I MH>1.5, wherein D is the effective aperture of the last lens of the lens optical system, and I MH is the size of the target surface of the lens optical system.

[0040] The beneficial effect of this embodiment is that by satisfying the range of the above formula, the overall light can be relatively smoothly transitioned to the image plane, reducing CRA and tolerance, making the lens more manufacturable and more mass-producible. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The following is an explanation of the various figures:

[0042] Figure 1 FIG. 4 is a structural diagram of the optical system of the lens in the first embodiment.

[0043] Figure 2 This is the MTF diagram of the first embodiment when the visible light is at 435-650nm.

[0044] Figure 3This is a distortion diagram when the visible light is at 435-650nm in the first embodiment.

[0045] Figure 4 This is a longitudinal chromatic aberration curve diagram when the visible light is in the range of 435-650nm in the first embodiment.

[0046] Figure 5 This is a lateral chromatic aberration curve diagram when the visible light is in the range of 435-650nm in the first embodiment.

[0047] Figure 6 This is a spot diagram when the visible light is at 435-650nm in the first embodiment.

[0048] Figure 7 It is the relative illumination under the condition of visible light being at 435-650nm in the first embodiment.

[0049] Figure 8 FIG. 4 is a structural diagram of the optical system of the lens in the second embodiment.

[0050] Fig. 9 This is the MTF diagram of the second embodiment when the visible light is at 435-650nm.

[0051] Fig.10 This is a distortion diagram when the visible light is at 435-650nm in the second embodiment.

[0052] Fig.11 This is a longitudinal chromatic aberration curve diagram when the visible light is in the range of 435-650nm in the second embodiment.

[0053] Fig.12 FIG. 4 is a lateral chromatic aberration curve diagram when the visible light is within the range of 435-650 nm in the second embodiment.

[0054] Fig.13 This is a spot diagram when the visible light is at 435-650nm in the second embodiment.

[0055] Fig.14 It is the relative illumination when the visible light is at 435-650nm in the second embodiment.

[0056] Fig.15 FIG. 4 is a structural diagram of the optical system of the lens in the third embodiment.

[0057] Fig.16 This is the MTF diagram of the third embodiment when the visible light is at 435-650nm.

[0058] Fig.17 This is a distortion diagram when the visible light is at 435-650nm in the third embodiment.

[0059] Fig.18 This is a longitudinal chromatic aberration curve diagram when the visible light is in the range of 435-650nm in the third embodiment.

[0060] Fig.19 FIG. 4 is a lateral chromatic aberration curve diagram when the visible light is within the range of 435-650 nm in the third embodiment.

[0061] Fig. 20 This is a spot diagram when the visible light is at 435-650nm in the third embodiment.

[0062] Fig.21 It is the relative illumination when the visible light is at 435-650nm in the third embodiment.

[0063] The above drawings include the following reference numerals:

[0064] 01. First lens; 02. Second lens; 03. Third lens; 04. Fourth lens; 05. Fifth lens; 06. Sixth lens; 07. Seventh lens; 08. Eighth lens; 09. Ninth lens; 10. Tenth lens; 11. Aperture; 12. Filter; 13. Protective glass. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0066] Reference Figures 1 to 21 As shown, an optical imaging lens (hereinafter referred to as lens) includes a first lens 01, a second lens 02, a third lens 03, a fourth lens 04, a fifth lens 05, a sixth lens 06, a seventh lens 07, an eighth lens 08, a ninth lens 09 and a tenth lens 10 which are arranged in sequence along an optical axis from an object side to an image side, and an aperture 11 is provided between the fifth lens 05 and the sixth lens 06:

[0067] The first lens 01 has a positive refractive power, the object side surface of the first lens 01 is a convex surface, and the image side surface of the first lens 01 is a convex surface;

[0068] The second lens 02 has a negative refractive power, the object side surface of the second lens 02 is a convex surface, and the image side surface of the second lens 02 is a concave surface;

[0069] The third lens 03 has a negative refractive power, the object side surface of the third lens 03 is a convex surface, and the image side surface of the third lens 03 is a concave surface;

[0070] The fourth lens 04 has a negative refractive power, the object side surface of the fourth lens 04 is a convex surface, and the image side surface of the fourth lens 04 is a concave surface;

[0071] The fifth lens 05 has a positive refractive power, the object side surface of the fifth lens 05 is a convex surface, and the image side surface of the fifth lens 05 is a convex surface;

[0072] The sixth lens 06 has a positive refractive power, the object side surface of the sixth lens 06 is a convex surface, and the image side surface of the sixth lens 06 is a convex surface;

[0073] The seventh lens 07 has a negative refractive power, the object side surface of the seventh lens 07 is a convex surface, and the image side surface of the seventh lens 07 is a concave surface;

[0074] The eighth lens 08 has a negative refractive power, the object side surface of the eighth lens 08 is a convex surface, and the image side surface of the eighth lens 08 is a concave surface;

[0075] The ninth lens 09 has a positive refractive power, the object side surface of the ninth lens 09 is a convex surface, and the image side surface of the ninth lens 09 is a convex surface;

[0076] The tenth lens element 10 has positive refractive power, the object side surface of the tenth lens element 10 is a convex surface, and the image side surface of the tenth lens element 10 is a convex surface.

[0077] The beneficial effects of this embodiment are: by optimizing the three different object distances of the main working distance, the closer working distance and the farther working distance, the same optical path and the same optical back focus are controlled, and the continuous focusing solution commonly used in the industry is omitted while meeting the customer's optical performance requirements.

[0078] It should be noted that the utility model provides three embodiments of an optical imaging lens. In the first embodiment and the third embodiment, the lens includes a first lens 01 to a tenth lens 10, and a filter 12 and a protective glass 13 are provided on the image side of the tenth lens 10. In the second embodiment, the lens includes a first lens 01 to a ninth lens 09, and a filter 12 and a protective glass 13 are provided on the image side of the ninth lens 09.

[0079] Furthermore, the lens satisfies the following relationship: T1 / D1≥9.5, and R1, R2 are both>0, 10<f1<60, wherein T1 is the center thickness of the first lens 01, D1 is the outer diameter of the first lens 01, R1 is the curvature radius of the object side of the first lens 01, R2 is the curvature radius of the image side of the first lens 01; f1 is the focal length of the first lens 01.

[0080] The beneficial effect of this embodiment is that the above range is satisfied, which is conducive to making the lens meet the close object distance and distortion-free characteristics.

[0081] Furthermore, the lens satisfies the following relationship: -15<f2<-5, -15<f3<-5, -15<f4<-5, wherein f2 is the focal length of the second lens 02, f3 is the focal length of the third lens 03, and f4 is the focal length of the fourth lens 04.

[0082] The beneficial effects of this embodiment are as follows: satisfying the above range is conducive to enabling the lens to meet the requirements of close object distance and wide angle; the second lens 02, the third lens 03 and the fourth lens 04 use three continuous meniscus complex lenses, which can ensure a large field of view, a large angle and a large aperture ratio for the optical system, and is conducive to compressing the aperture of the optical element to achieve a miniaturized design of the lens.

[0083] Furthermore, the lens satisfies the following relationship: 5<f5<15, wherein f5 is the focal length of the fifth lens 05.

[0084] The beneficial effects of this embodiment are: satisfying the above range is conducive to balancing the focal length of the lens to ensure a smaller deflection angle, and playing a role in smoothing the transition of light.

[0085] Furthermore, the lens satisfies the following relationship: Nd 6 >1.65,Vd 6 <55,5<f6<15,where Nd 6 is the refractive index coefficient of the sixth lens 06, Vd 6 is the Abbe coefficient of the sixth lens 06, and f6 is the focal length of the sixth lens 06.

[0086] Furthermore, the lens satisfies the following relationship: Nd 7 >1.90,Vd 6 <20,-20<f7<-5,where Nd 7 is the refractive index coefficient of the seventh lens 07, Vd 7 is the Abbe coefficient of the seventh lens 07; f7 is the focal length of the seventh lens 07.

[0087] Furthermore, the lens satisfies the following relationship: Nd 8 >1.95,Vd 8 <25,-15<f8<-5,where Nd 8 is the refractive index of the eighth lens 08, Vd 8 is the Abbe coefficient of the eighth lens 08, and f8 is the focal length of the eighth lens 08.

[0088] The beneficial effect of this embodiment is that by satisfying the above range and matching the eighth lens 08 with the ninth lens 09 made of low dispersion material, it is beneficial to correct the secondary chromatic aberration and can effectively improve the imaging quality.

[0089] Furthermore, the lens satisfies the following relationship: Nd 9 <1.6,Vd 9 >65, 5<f9<10, dn / dT<-6.5*10E-6 in the temperature range of -40℃~105℃, where Nd 9 is the refractive index Vd of the ninth lens 09 9 is the Abbe coefficient of the ninth lens 09, f9 is the focal length of the ninth lens 09, and dn / dT is the refractive index temperature coefficient of the material used for the ninth lens 09.

[0090] The beneficial effect of this embodiment is that the ninth lens 09 is made of a material with a negative refractive index temperature coefficient, which can effectively balance the temperature drift and realize the athermal design of the lens.

[0091] Furthermore, in the first embodiment and the third embodiment, the lens satisfies the following relationship: Vd 9 -Vd 8 >40, wherein the eighth lens 08 and the ninth lens 09 are a cemented lens group, Vd 8 is the Abbe coefficient of the eighth lens 08, Vd 9 is the Abbe coefficient of the ninth lens element 09.

[0092] The beneficial effects of this embodiment are as follows: the eighth lens 08 and the ninth lens 09 adopt a combination of high and low dispersion, which is beneficial to correcting secondary chromatic aberration and can effectively improve the imaging quality of the lens.

[0093] Furthermore, in the second embodiment, the lens satisfies the following relationship: Vd 8 -Vd 7 >50, wherein the seventh lens 07 and the eighth lens 08 are a cemented lens group, Vd 7 is the Abbe coefficient of the seventh lens 07, Vd 8 is the Abbe coefficient of the eighth lens 08.

[0094] The beneficial effects of this embodiment are as follows: the seventh lens 07 and the eighth lens 08 adopt a combination of high and low dispersion, which is beneficial to correcting secondary chromatic aberration and can effectively improve the imaging quality of the lens.

[0095] Furthermore, the lens satisfies the following relationship: Nd 10 >1.75, where Nd 10 is the refractive index coefficient of the tenth lens 10.

[0096] The beneficial effects of this embodiment are as follows: the tenth lens 10 is made of a high refractive index material, which is beneficial to improving the resolution of the lens and compressing the diameter of the rear port of the lens.

[0097] Furthermore, the lens satisfies the following relationship: TTL<28.5, BFL≥3.45, wherein TTL is the total length of the lens optical system; BFL is the optical back focus of the lens optical system.

[0098] The beneficial effect of this embodiment is: by satisfying the range of the above formula, the lens has an appropriate back focus, and the appropriate back focus is beneficial to reducing the temperature drift caused by mechanical parts, which can reduce the temperature drift of the entire lens optical system and is beneficial to the athermal design of the lens.

[0099] Furthermore, the lens satisfies the following relationship: D / I MH>1.5, where D is the effective aperture of the last lens of the lens optical system, and I MH is the target surface size of the lens optical system. That is, in the first and third embodiments, D is the effective aperture of the tenth lens 10; in the second embodiment, D is the effective aperture of the ninth lens 09.

[0100] The beneficial effect of this embodiment is that by satisfying the range of the above formula, the overall light can be relatively smoothly transitioned to the image plane, reducing CRA and tolerance, making the lens more manufacturable and more mass-producible.

[0101] In summary, the advantages of the lens of the utility model are:

[0102] First, the lens takes into account the various trust requirements of special scene recognition and has high reliability. The first lens 01 is made of spherical glass material with high hardness;

[0103] Secondly, when designing the lens, we optimize the three different object distances: the main working distance, the closer working distance, and the farther working distance, and control the same optical path and the same optical back focus. This eliminates the continuous focusing solution commonly used in the industry while meeting the customer's optical performance requirements.

[0104] Third, the lens has moderate light transmission, the lens aperture is F=2.0, and the relative aperture is moderate, which can better take into account both shallow depth of field, small amount of picture information, and poor low illumination.

[0105] Fourthly, it has high mass producibility, small lens outer diameter and short total length; it solves the problem of macro lenses that cannot take into account both high image quality and miniaturization.

[0106] Fifth, the lens meets the working temperature drift requirements of -40℃ to 105℃, and cooperates with the lens and receiver to achieve a heatless design; solving the problem of poor optical performance of the lens when the system components heat up.

[0107] Sixth, the ghost image has low energy and occupies small pixels.

[0108] The present invention will be described in more detail below in conjunction with Tables 1 to 4. It should be noted that the following tables are only specific embodiments of the present invention, rather than limiting examples.

[0109] Table 1 is a specific arrangement table of parameters such as the curvature radius, thickness, and refractive index of each lens in the first embodiment of the utility model.

[0110]

[0111] In the first embodiment, the focal length of the optical system is f=3.65 mm, the light transmission FNO=2.0, the field of view angle FOV=85°, the target surface size IMH=6.56 mm, and the total optical length TTL=28.23 mm.

[0112] Table 2 is a specific arrangement table of parameters such as the curvature radius, thickness, and refractive index of each lens in the second embodiment of the utility model.

[0113]

[0114] In the second embodiment, the focal length of the optical system is f=3.8 mm, the light transmission FNO=2.0, the field of view angle FOV=85°, the target surface size IMH=6.56 mm, and the total optical length TTL=31.2 mm.

[0115] Table 3 is a specific arrangement table of parameters such as the curvature radius, thickness, and refractive index of each lens in the third embodiment of the present utility model.

[0116]

[0117] In the third embodiment, the focal length of the optical system is f=3.66 mm, the light transmission FNO=2.0, the field of view angle FOV=85°, the target surface size IMH=6.56 mm, and the total optical length TTL=28.25 mm.

[0118] Table 4 is a specific arrangement table of parameters such as optical back focus and field angle of the first to third embodiments of the utility model. In the table, f is the focal length, BFL is the optical back focus, y is the image height of the lens, TTL is the total optical length of the lens, FOV is the field angle, T1 is the center thickness of the first lens, D1 is the outer diameter of the first lens, D is the effective aperture of the last lens of the lens optical system, and h is the total image height of the lens.

[0119] parameter First embodiment Second embodiment Third embodiment D1 12.5 10.75 11.67 T1 1.322 1.7 3 D1 / T1≤12 9.46 6.32 3.89 TTL 28.23 31.2 28.25 BFL 3.46 4 3.67 TTL / BFL 8.158959538 7.8 7.697547684 h 6.56 6.56 5.244 TTL / h≤5.5 4.30 4.76 5.39 f 3.65 3.80 3.66 FOV 85 85 72.3 FOV*f / h 47.29420732 45.33333333 38.56 D / h 1.905487805 1.638719512 2.225400458

[0120] The following is an explanation of the various figures:

[0121] Figure 2This is the MTF diagram of the first embodiment when the visible light is at 435-650nm. It can be seen from the figure that when the field of view angle FOV = 79.52° and the target surface size IMH = 5.914mm, the MTF value is 1001p / mm>0.35; when the field of view angle FOV = 85° and the target surface size IMH = 6.56mm, the MTF value is 801p / mm>0.25. The above shows that the lens of this embodiment has high resolution and good imaging quality.

[0122] Figure 3 This is a distortion diagram of the first embodiment when the visible light is at 435-650nm. It can be seen from the figure that the edge field distortion values ​​are all less than ±3%, the optical distortion is small under a large field angle, the imaging effect is good, and the imaging restoration degree is high.

[0123] Figure 4 This is a longitudinal chromatic aberration curve diagram of the first embodiment when the visible light is in the range of 435-650nm. It can be seen from the figure that the axial chromatic aberration of the lens is small, the longitudinal chromatic aberration of the full field of view is less than 4.5um, the color reproduction is good, the color difference is small, and the blue-purple edge phenomenon is not obvious.

[0124] Figure 5 The lateral chromatic aberration curve of the first embodiment when the visible light is in the range of 435-650nm is shown in the figure. It can be seen from the figure that the lens has a small spherical aberration, high color reproduction, and the color focus shift is less than 0.08mm in the entire field of view.

[0125] Figure 6 This is the spot diagram of the first embodiment when the visible light is in the range of 435-650 nm. It can be seen from the figure that the more compact the spot diagram is, the smaller the aberration is.

[0126] Figure 7 It is the relative illumination of the first embodiment when the visible light is at 435-650nm. It can be seen from the figure that when the half field of view HFOV of the lens is ensured to be 42.5, the relative illumination is greater than 55%.

[0127] Fig. 9 This is the MTF diagram of the second embodiment when the visible light is at 435-650nm. It can be seen from the figure that when the field of view angle FOV = 79.52° and the target surface size IMH = 5.914mm, the MTF value is 100lp / mm>0.30; when the field of view angle FOV = 85° and the target surface size IMH = 6.56mm, the MTF value is 80lp / mm>0.18. The above shows that the lens of this embodiment has high resolution and good imaging quality.

[0128] Fig.10This is a distortion diagram of the second embodiment when the visible light is at 435-650nm. It can be seen from the figure that the edge field distortion values ​​are all less than ±10%, the optical distortion under a large field angle is small but slightly worse than the first embodiment, the imaging effect is good, and the imaging restoration degree is high.

[0129] Fig.11 The longitudinal chromatic aberration curve of the second embodiment under the condition of visible light being 435-650nm is shown in the figure. It can be seen from the figure that the axial chromatic aberration of the lens is small, the longitudinal chromatic aberration of the whole field of view is less than 4.5um, the color reproduction is good, the color difference is small, and the blue-purple edge phenomenon is not obvious.

[0130] Fig.12 The lateral chromatic aberration curve of the second embodiment when the visible light is in the range of 435-650nm is shown in the figure. It can be seen from the figure that the lens has a small spherical aberration, high color restoration, and the color focus shift is less than 0.05mm in the entire field of view.

[0131] Fig.13 This is the spot diagram of the second embodiment when the visible light is at 435-650nm. It can be seen from the figure that the more compact the spot diagram is, the smaller the aberration is, but it is slightly worse than the first embodiment.

[0132] Fig.14 It is the relative illumination of the second embodiment when the visible light is at 435-650nm. It can be seen from the figure that when the half field of view HFOV is 42.5, the relative illumination is greater than 75%, which is better than the first embodiment.

[0133] Fig.16 This is the MTF diagram of the third embodiment when the visible light is at 435-650nm. It can be seen from the figure that when the field of view angle FOV = 79.52° and the target surface size IMH = 5.914mm, the MTF value is 100lp / mm>0.4; when the field of view angle FOV = 85° and the target surface size IMH = 6.56mm, the MTF value is 80lp / mm>0.3. The above shows that the lens of this embodiment has high resolution and good imaging quality, which is better than the first and second embodiments.

[0134] Fig.17 This is a distortion diagram of the third embodiment when the visible light is at 435-650nm. It can be seen from the figure that the edge field distortion values ​​are all less than ±2.5%, the optical distortion is small under a large field angle, the imaging effect is good, and the imaging restoration degree is high.

[0135] Fig.18 The longitudinal chromatic aberration curve of the third embodiment under the condition of visible light being 435-650nm is shown in the figure. It can be seen from the figure that the axial chromatic aberration of the lens is small, the longitudinal chromatic aberration of the whole field of view is less than 4um, the color reproduction is good, the color difference is small, and the blue-purple edge phenomenon is not obvious, which is better than the first and second embodiments.

[0136] Fig.19 The lateral chromatic aberration curve of the third embodiment when the visible light is in the range of 435-650nm is shown in the figure. It can be seen from the figure that the lens has a small spherical aberration, high color reproduction, and the color focus shift is less than 0.1mm in the whole field of view.

[0137] Fig. 20 This is the spot diagram of the third embodiment when the visible light is in the range of 435-650nm. It can be seen from the figure that the more compact the spot diagram is, the smaller the aberration is, which is better than the first and second embodiments.

[0138] Fig.21 It is the relative illumination of the third embodiment when the visible light is at 435-650nm. It can be seen from the figure that when the half field of view HFOV is 42.5, the relative illumination is greater than 70%, which is better than the first embodiment.

[0139] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0140] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0141] The above description is only the preferred implementation of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An optical imaging lens, characterized in that: The invention comprises 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 which are arranged in sequence along the optical axis from the object side to the image side, wherein: The first lens has positive refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a convex surface; The second lens has a negative refractive power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; The third lens has a negative refractive power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; The fourth lens has a negative refractive power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a concave surface; The fifth lens has positive refractive power, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is convex; The sixth lens has positive refractive power, the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface; The seventh lens has a negative refractive power, the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface; The eighth lens has a negative refractive power, the object side surface of the eighth lens is a convex surface, and the image side surface of the eighth lens is a concave surface; The ninth lens element has positive refractive power, the object side surface of the ninth lens element is a convex surface, and the image side surface of the ninth lens element is a convex surface.

2. The optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: T1 / D1≥9.5, and R1, R2 are both>0, 10<f1<60, wherein T1 is the center thickness of the first lens, D1 is the outer diameter of the first lens, R1 is the curvature radius of the object side of the first lens, R2 is the curvature radius of the image side of the first lens; and f1 is the focal length of the first lens.

3. The optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: -15<f2<-5, -15<f3<-5, -15<f4<-5, wherein f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f4 is the focal length of the fourth lens.

4. The optical imaging lens according to claim 1, wherein: The lens satisfies the following relationship: 5<f5<15, wherein f5 is the focal length of the fifth lens.

5. The optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Nd6>1.65, Vd6<55, 5<f6<15, wherein Nd6 is the refractive index coefficient of the sixth lens, Vd6 is the Abbe coefficient of the sixth lens, and f6 is the focal length of the sixth lens.

6. The optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Nd7>1.90, Vd6<20, -20<f7<-5, wherein Nd7 is the refractive index coefficient of the seventh lens, Vd7 is the Abbe coefficient of the seventh lens; and f7 is the focal length of the seventh lens.

7. The optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Nd8>1.95, Vd8<25, -15<f8<-5, wherein Nd8 is the refractive index of the eighth lens, Vd8 is the Abbe coefficient of the eighth lens, and f8 is the focal length of the eighth lens.

8. The optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Nd9<1.6, Vd9>65, 5<f9<10, and dn / dT<-6.5*10E-6 in the temperature range of -40℃~105℃, wherein Nd9 is the refractive index of the ninth lens, Vd9 is the Abbe coefficient of the ninth lens, and f9 is the focal length of the ninth lens. dn / dT is the refractive index temperature coefficient of the material used for the ninth lens.

9. The optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Vd9-Vd8>40, wherein the eighth lens and the ninth lens are a cemented lens group, Vd8 is the Abbe coefficient of the eighth lens, and Vd9 is the Abbe coefficient of the ninth lens.

10. The optical imaging lens according to claim 1, characterized in that: A tenth lens is disposed on the image side of the ninth lens, the tenth lens has a positive refractive power, the object side surface of the tenth lens is a convex surface, and the image side surface of the tenth lens is a convex surface; The lens satisfies the following relationship: Nd 10 >1.75, where Nd 10 is the refractive index coefficient of the tenth lens.

Images