Imaging lens

Abstract

The utility model provides an imaging 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 which are sequentially arranged along an optical axis from an object side to an image side, and the optical structure can be better optimized by reasonably distributing the positions and gluing relations of a lens group formed by the lenses. Lens distortion is reduced, and lens structure design and assembly are facilitated; the lens is large in image surface design and high in pixel, and meets the requirements of a 4K-level vehicle-mounted sensor; the lens is large in light transmission, the aperture is F1.7, and the low-illumination effect is good; the lens is high in mass production, small in outer diameter and long in total length; the lens meets the temperature drift requirement of a vehicle gauge from-40 DEG C to 105 DEG C, and athermalization design is adopted; the ghost image is considered in real time in the lens design process, the ghost image energy is low, and the pixel occupied by the ghost image is small.

Description

Technical Field

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

[0002] As people's requirements for driving experience continue to increase, automotive optical lenses are increasingly used in intelligent driving, and the status of automotive optical lenses in the automotive-related industries continues to improve.

[0003] Advanced driver assistance system (ADAS) plays an important role in intelligent driving. It uses various lenses and sensors to collect environmental information to ensure the driver's driving safety. In the existing technology, the defects of the lens of ADAS system are: first, the resolution is not high, especially in the large target area, the resolution drops sharply; second, the light transmission is small, the energy utilization rate is not high, and the low-light effect is not good; third, to achieve high quality of the lens, it will cause a complex structure, a large outer diameter, and a long total length; fourth, the lens is easy to lose focus at high and low temperatures, which cannot meet the requirements of vehicle regulations; fifth, the ghost image of the lens has a large energy and the ghost image occupies a large number of pixels. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide an imaging lens to solve the problems mentioned in the above background technology section.

[0005] The utility model is realized by the following technical solutions:

[0006] An imaging lens 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 side to an image side, wherein:

[0007] The object side surface of the first lens is convex, the image side surface of the first lens is concave, and the first lens has negative refractive power;

[0008] The object side surface of the second lens is a convex surface, the image side surface of the second lens is a convex surface, and the second lens has a positive refractive power;

[0009] The object side surface of the third lens is a concave surface, the image side surface of the third lens is a convex surface, and the third lens has a negative refractive power;

[0010] The object side surface of the fourth lens is a convex surface, the image side surface of the fourth lens is a convex surface, and the fourth lens has a positive refractive power;

[0011] The object side surface of the fifth lens is a concave surface, the image side surface of the fifth lens is a concave surface, and the fifth lens has a negative refractive power;

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

[0013] The object side surface of the seventh lens is a convex surface, the image side surface of the seventh lens is a convex surface, and the seventh lens has positive refractive power.

[0014] The beneficial effect of this embodiment is that by reasonably allocating the positions and gluing relationships of the lenses constituting the lens group, the optical structure can be optimized relatively well, lens distortion can be reduced, and at the same time, it is more conducive to lens structure design and assembly.

[0015] Furthermore,

[0016] The lens satisfies the following relationship: D1 / T1≥6.5, and DR2 / R2≤0.5, wherein T1 is the center thickness of the first lens, D1 is the outer diameter of the first lens, DR2 is the aperture of the image side of the first lens, and R2 is the curvature radius of the image side of the first lens.

[0017] The beneficial effects of this embodiment are: by satisfying the above range, the reliability and dependability of the lens system can be improved, and reliability tests such as falling ball and falling gravel can be satisfied.

[0018] Furthermore, the lens satisfies the following relationship: 0.8<f1 / f2<1.3, wherein f1 is the focal length of the first lens, and f2 is the focal length of the second lens.

[0019] The beneficial effects of this embodiment are: satisfying the range of the above formula is beneficial to balancing the optical focal length and improving the performance of the lens system.

[0020] Furthermore, the lens satisfies the following relationship: -0.8>f3 / f4>-1.3, wherein f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens.

[0021] The beneficial effect of this embodiment is: satisfying the above range is conducive to balancing the optical power and controlling temperature drift. Further, the lens satisfies the following relationship: Nd2>2.0, where Nd2 is the refractive index coefficient of the second lens.

[0022] The beneficial effect of this embodiment is that: by satisfying the above range, the second lens can have a very high refractive index, which can effectively increase the field of view FOV and meet the requirements of miniaturization of the optical system.

[0023] Furthermore, the lens satisfies the following relationship: Vd3<50, wherein Vd3 is the Abbe coefficient of the third lens.

[0024] The beneficial effect of this embodiment is that the use of low-dispersion material for the third lens is conducive to correcting secondary chromatic aberration and can effectively improve imaging quality.

[0025] Further, Vd4>70, Nd4<1.6, wherein Vd4 is the Abbe coefficient of the third lens, Nd4 is the refractive index of the fourth lens, and the fourth lens is a positive lens;

[0026] And the lens satisfies the following relationship: In the temperature range of -40℃-105℃ dn / dT<

[0027] -8.5*10E-6, where dn / dT is the temperature coefficient of the refractive index of the material.

[0028] The beneficial effect of this embodiment is that the fourth lens is made of a material with a negative refractive index coefficient, which can effectively balance the temperature drift and achieve athermalization.

[0029] Furthermore, the lens satisfies the following relationship: Vd5<50, wherein Vd5 is the Abbe coefficient of the fifth lens.

[0030] The beneficial effects of this embodiment are: the fifth lens adopts low dispersion material, which is conducive to correcting secondary chromatic aberration and can effectively improve the imaging quality.

[0031] Furthermore, the fourth lens and the fifth lens are a cemented lens group, and the lens satisfies the following relationship: Vd4-Vd5>50, wherein Vd4 is the Abbe coefficient of the fourth lens, and Vd5 is the Abbe coefficient of the fifth lens.

[0032] The beneficial effect of this embodiment is that the high and low dispersion combination of the fourth lens and the fifth lens is conducive to correcting the secondary chromatic aberration and can effectively improve the imaging quality.

[0033] Furthermore, the lens satisfies the following relationship: Nd6>1.8, Nd7>1.8, wherein Nd6 is the refractive index coefficient of the sixth lens, and Nd7 is the refractive index coefficient of the seventh lens.

[0034] The beneficial effects of this embodiment are as follows: the sixth lens and the seventh lens are made of high refractive index materials, which can improve the resolution and compress the diameter of the rear port of the lens.

[0035] Furthermore, the lens satisfies the following relationship: TTL / BFL≥4, wherein TTL is the total length of the lens system; and BFL is the optical back focus of the lens system.

[0036] The beneficial effects of this embodiment are as follows: appropriate back focus is helpful to reduce the temperature drift caused by mechanical parts, which can reduce the temperature drift of the entire system and is conducive to athermalization.

[0037] Furthermore, the lens satisfies the following relationship: D / IMH>0.9, wherein D is the effective aperture of the last lens of the optical system, and IMH is the size of the target surface of the optical system.

[0038] The beneficial effects of this embodiment are: satisfying the range of the above formula, the overall light can be relatively smoothly transitioned to the image plane, CRA is reduced, tolerance and manufacturability are strong, and mass production is more possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the optical path of the first embodiment of the utility model.

[0040] Figure 2 This is the MTF diagram of the first embodiment under the visible light range of 435-650nm.

[0041] Figure 3 This is the distortion diagram under visible light 435-650nm in Example 1.

[0042] Figure 4 This is a longitudinal chromatic aberration curve diagram under visible light 435-650nm in Example 1.

[0043] Figure 5 This is a lateral chromatic aberration curve diagram under visible light 435-650nm in Example 1.

[0044] Figure 6 This is the spot diagram under visible light 435-650nm in Example 1.

[0045] Figure 7 This is a relative illumination diagram under visible light 435-650nm in Example 1.

[0046] Figure 8 This is a light path principle diagram of the second embodiment of the utility model.

[0047] Fig. 9 This is the MTF diagram of the second embodiment under visible light 435-650nm.

[0048] Fig.10 This is a distortion diagram under visible light 435-650nm in the second embodiment.

[0049] Fig.11 It is a longitudinal chromatic aberration curve diagram under visible light 435-650nm in the second embodiment.

[0050] Fig.12 It is a lateral chromatic aberration curve diagram under visible light 435-650nm in the second embodiment.

[0051] Fig.13 It is the spot diagram under visible light 435-650nm in the second embodiment.

[0052] Fig.14 This is a relative illumination diagram under visible light 435-650nm in the second embodiment.

[0053] Fig.15 This is a schematic diagram of the optical path of the third embodiment of the utility model.

[0054] Fig.16 This is the MTF diagram of the third embodiment under visible light 435-650nm.

[0055] Fig.17 This is a distortion diagram under visible light 435-650nm in the third embodiment.

[0056] Fig.18 It is a longitudinal chromatic aberration curve diagram under visible light 435-650nm in the third embodiment.

[0057] Fig.19 It is a lateral chromatic aberration curve diagram under visible light 435-650nm in the third embodiment.

[0058] Fig. 20 It is the spot diagram under visible light 435-650nm in the third embodiment.

[0059] Fig.21 This is a relative illumination diagram under visible light 435-650nm in the third embodiment.

[0060] The above drawings include the following reference numerals:

[0061] 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. Aperture; 10. Filter; 11. Protective glass. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is claimed, but merely represents selected embodiments of the utility model.

[0063] 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.

[0064] Reference Figures 1 to 21 As shown, an imaging lens comprises a first lens 01, a second lens 02, a third lens 03, a fourth lens 04, a fifth lens 05, a sixth lens 06 and a seventh lens 07 which are arranged in sequence along an optical axis from an object side to an image side, wherein:

[0065] The object side surface of the first lens 01 is convex, the image side surface of the first lens 01 is concave, and the first lens 01 has negative refractive power;

[0066] The object side surface of the second lens 02 is a convex surface, the image side surface of the second lens 02 is a convex surface, and the second lens 02 has a positive refractive power;

[0067] The object side surface of the third lens 03 is a concave surface, the image side surface of the third lens 03 is a convex surface, and the third lens 03 has a negative refractive power;

[0068] The object side surface of the fourth lens 04 is a convex surface, the image side surface of the fourth lens 04 is a convex surface, and the fourth lens 04 has a positive refractive power;

[0069] The object side surface of the fifth lens 05 is a concave surface, the image side surface of the fifth lens 05 is a concave surface, and the fifth lens 05 has a negative refractive power;

[0070] The object side surface of the sixth lens 06 is a concave surface, the image side surface of the sixth lens 06 is a convex surface, and the sixth lens 06 has a positive refractive power;

[0071] The object side surface of the seventh lens 07 is a convex surface, the image side surface of the seventh lens 07 is a convex surface, and the seventh lens 07 has a positive refractive power.

[0072] The beneficial effect of this embodiment is that by reasonably allocating the positions and gluing relationships of the lenses constituting the lens group, the optical structure can be optimized relatively well, lens distortion can be reduced, and at the same time, it is more conducive to lens structure design and assembly.

[0073] Furthermore,

[0074] The lens satisfies the following relationship: D1 / T1≥6.5, and DR2 / R2≤0.5, wherein T1 is the center thickness of the first lens 01, D1 is the outer diameter of the first lens 01, DR2 is the aperture of the image side of the first lens 01, and R2 is the curvature radius of the image side of the first lens 01.

[0075] The beneficial effects of this embodiment are: by satisfying the above range, the reliability and dependability of the lens system can be improved, and reliability tests such as falling ball and falling gravel can be satisfied.

[0076] Furthermore, the lens satisfies the following relationship: 0.8<f1 / f2<1.3, wherein f1 is the focal length of the first lens 01 , and f2 is the focal length of the second lens 02 .

[0077] The beneficial effects of this embodiment are: satisfying the range of the above formula is beneficial to balancing the optical focal length and improving the performance of the lens system.

[0078] Furthermore, the lens satisfies the following relationship: -0.8>f3 / f4>-1.3, wherein f4 is the focal length of the fourth lens 04 , and f5 is the focal length of the fifth lens 05 .

[0079] The beneficial effect of this embodiment is: satisfying the above range is conducive to balancing the optical power and controlling temperature drift. Further, the lens satisfies the following relationship: Nd2>2.0, where Nd2 is the refractive index coefficient of the second lens 02.

[0080] The beneficial effects of this embodiment are as follows: by satisfying the above range, the second lens 02 can have a very high refractive index, which can effectively increase the field of view FOV and meet the requirements for miniaturization of the optical system.

[0081] Furthermore, the lens satisfies the following relationship: Vd3<50, where Vd3 is the Abbe coefficient of the third lens 03.

[0082] The beneficial effects of this embodiment are as follows: the third lens 03 is made of low-dispersion material, which is conducive to correcting secondary chromatic aberration and can effectively improve imaging quality.

[0083] Further, Vd4>70, Nd4<1.6, wherein Vd4 is the Abbe coefficient of the third lens 03, Nd4 is the refractive index of the fourth lens 04, and the fourth lens 04 is a positive lens;

[0084] And the lens satisfies the following relationship: In the temperature range of -40℃-105℃ dn / dT<

[0085] -8.5*10E-6, where dn / dT is the temperature coefficient of the refractive index of the material.

[0086] The beneficial effect of this embodiment is that the fourth lens 04 is made of a material with a negative refractive index coefficient, which can effectively balance the temperature drift and achieve athermalization.

[0087] Furthermore, the lens satisfies the following relationship: Vd5<50, wherein Vd5 is the Abbe coefficient of the fifth lens 05 .

[0088] The beneficial effects of this embodiment are: the fifth lens 05 uses a low-dispersion material, which is conducive to correcting secondary chromatic aberration and can effectively improve the imaging quality.

[0089] Furthermore, the fourth lens 04 and the fifth lens 05 are a cemented lens group, and the lens satisfies the following relationship: Vd4-Vd5>50, wherein Vd4 is the Abbe coefficient of the fourth lens 04, and Vd5 is the Abbe coefficient of the fifth lens 05.

[0090] The beneficial effects of this embodiment are as follows: the high and low dispersion combination of the fourth lens 04 and the fifth lens 05 is conducive to correcting secondary chromatic aberration and can effectively improve imaging quality.

[0091] Furthermore, the lens satisfies the following relationship: Nd6>1.8, Nd7>1.8, wherein Nd6 is the refractive index coefficient of the sixth lens 06 , and Nd7 is the refractive index coefficient of the seventh lens 07 .

[0092] The beneficial effects of this embodiment are as follows: the sixth lens 06 and the seventh lens 07 are made of high refractive index materials, which can improve the resolution and reduce the diameter of the lens rear port.

[0093] Furthermore, the lens satisfies the following relationship: TTL / BFL≥4, wherein TTL is the total length of the lens system; and BFL is the optical back focus of the lens system.

[0094] The beneficial effects of this embodiment are as follows: appropriate back focus is helpful to reduce the temperature drift caused by mechanical parts, which can reduce the temperature drift of the entire system and is conducive to athermalization.

[0095] Furthermore, the lens satisfies the following relationship: D / IMH>0.9, wherein D is the effective aperture of the last lens of the optical system, and IMH is the size of the target surface of the optical system.

[0096] The beneficial effects of this embodiment are: satisfying the range of the above formula, the overall light can be relatively smoothly transitioned to the image plane, CRA is reduced, tolerance and manufacturability are strong, and mass production is more possible.

[0097] The utility model provides detailed optical data of the first embodiment to the third embodiment as shown in Tables 1-1 to 1-3.

[0098] The conditional expressions of the first to third embodiments are as follows:

[0099] parameter First embodiment Second embodiment Third embodiment D1 11 12 11.6 T1 1.6 3.13 1 D1 / T1≤12 6.88 3.83 11.60 TTL 35 34.9 34.9 h 10.285 10.285 10.285 TTL / h≤5.5 3.40 3.39 3.39 f 7.90 7.90 7.90 FOV 75 75 75 FOV*f / h 40 40 40

[0100] Detailed optical data in Table 1-1. In the first embodiment, the focal length of the optical system is f=7.9 mm, the transmittance FNO=1.7, the field of view angle FOV=75°, the target surface size IMH=10.285 mm, and the total optical length TTL=35 mm.

[0101]

[0102] Detailed optical data in Table 1-2. In the second embodiment, the focal length of the optical system is f=7.9 mm, the transmittance FNO=1.7, the field of view angle FOV=75°, the target surface size IMH=10.285 mm, and the total optical length TTL=34.9 mm.

[0103]

[0104] Detailed optical data in Table 1-3, in the third embodiment, the focal length of the optical system is f=7.9 mm, the light transmission FNO=1.7, the field of view angle FOV=75°, the target surface size IMH=10.285 mm, and the total optical length TTL=34.9 mm.

[0105]

[0106] Figure 1 This is a schematic diagram of the optical path of the first embodiment of the utility model. In the first embodiment, the lens includes the first lens 01 to the seventh lens 07, the second lens 02 and the third lens 03 are glued together, the fourth lens 04 and the fifth lens 05 are glued together, an aperture 09 is provided between the third lens 03 and the fourth lens 04, and a filter 10 and a protective glass 11 are provided after the seventh lens 07.

[0107] Figure 2 This is the MTF diagram of the visible light 435-650nm in Example 1. It can be seen from the figure that under the conditions of field of view angle FOV = 75° and target surface size IMH = 10.285mm, the MTF value is greater than 0.4 at 80lp / mm; under the conditions of field of view angle FOV = 62.5° and target surface size IMH = 8.6mm, the MTF value is greater than 0.6 at 80lp / mm; the above shows that this example has high resolution and good imaging quality.

[0108] Figure 3 This is the distortion diagram under visible light 435-650nm in Example 1. It can be seen from the figure that the edge field distortion values ​​are all less than ±15%, the optical distortion under a large field angle is small, the imaging effect is good, and the imaging restoration degree is high.

[0109] Figure 4This is a longitudinal chromatic aberration curve under visible light 435-650nm in Example 1. 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 5um, the color reproduction is good, the color difference is small, and the blue-purple edge phenomenon is not obvious.

[0110] Figure 5 This is a lateral chromatic aberration curve diagram under visible light 435-650nm in Example 1. It can be seen from the figure that the lens has a small spherical aberration, high color restoration, and a color focus shift of less than 0.05mm in the entire field of view.

[0111] Figure 6 This is the spot diagram under visible light 435-650nm in Example 1. It can be seen from the figure that the more compact the spot diagram is, the smaller the aberration is.

[0112] Figure 7 This is a relative illumination diagram under visible light 435-650nm in Example 1. It can be seen from the figure that the relative illumination of the lens is greater than 80% when the horizontal viewing angle HFOV=37.5 is ensured.

[0113] Figure 8 This is a schematic diagram of the optical path of the second embodiment of the utility model. In the second embodiment, the lens includes the first lens 01 to the eighth lens 08, the fourth lens 04 and the fifth lens 05 are glued together, the sixth lens 06 and the seventh lens 07 are glued together, an aperture 09 is provided between the third lens 03 and the fourth lens 04, and a filter 10 and a protective glass 11 are provided after the eighth lens 08.

[0114] Fig. 9 This is the MTF diagram of the visible light 435-650nm in the second embodiment. It can be seen from the figure that under the conditions of field of view angle FOV = 75° and target surface size IMH = 10.285mm, the MTF value is greater than 0.4 at 80lp / mm; under the conditions of field of view angle FOV = 62.5° and target surface size IMH = 8.6mm, the MTF value is greater than 0.5 at 80lp / mm; the above shows that this example has high resolution and good imaging quality.

[0115] Fig.10 This is a distortion diagram of the second embodiment under visible light 435-650nm. It can be seen from the figure that the edge field distortion values ​​are all less than ±15%, the optical distortion is small under a large field angle, the imaging effect is good, and the imaging restoration degree is high.

[0116] Fig.11 The longitudinal chromatic aberration curve of the visible light 435-650nm in the second embodiment 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 full field of view is less than 6um, the color reproduction is good, the color difference is small, and the blue-purple edge phenomenon is not obvious.

[0117] Fig.12 The lateral chromatic aberration curve diagram of the second embodiment under the visible light 435-650nm. It can be seen from the figure that the lens has small spherical aberration, high color restoration, and the color focus shift is less than 0.05mm in the whole field of view.

[0118] Fig.13 This is the spot diagram of the second embodiment under the visible light 435-650nm. It can be seen from the figure that the more compact the spot diagram is, the smaller the aberration is.

[0119] Fig.14 This is a relative illumination diagram of the second embodiment under visible light 435-650nm. It can be seen from the figure that the relative illumination of the lens is greater than 60% when the horizontal viewing angle HFOV=37.5.

[0120] Fig.15 This is a schematic diagram of the optical path of the third embodiment of the utility model. In the third embodiment, the lens includes the first lens 01 to the eighth lens 08, the third lens 03 and the fourth lens 04 are glued together, the fifth lens 05 and the sixth lens 06 are glued together, an aperture 09 is provided between the fourth lens 04 and the fifth lens 05, and a filter 10 and a protective glass 11 are provided after the eighth lens 08.

[0121] Fig.16 This is the MTF diagram of the third embodiment under visible light 435-650nm. It can be seen from the figure that under the conditions of field of view FOV = 75° and target surface size IMH = 10.285mm, the MTF value is greater than 0.55 at 80lp / mm; the above shows that this example has high resolution and good imaging quality.

[0122] Fig.17 This is the distortion diagram of the third embodiment under visible light 435-650nm. It can be seen from the figure that the edge field distortion values ​​are all less than ±20%, the optical distortion is small under a large field angle, the imaging effect is good, and the imaging restoration degree is high

[0123] Fig.18 The longitudinal chromatic aberration curve diagram of the third embodiment under the visible light 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 whole field of view is less than 5um, the color reproduction is good, the color aberration is small, and the blue-purple edge phenomenon is not obvious.

[0124] Fig.19 This is a lateral chromatic aberration curve diagram of the third embodiment under visible light 435-650nm. 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 entire field of view.

[0125] Fig. 20This is the spot diagram of the third embodiment under visible light 435-650nm. It can be seen from the figure that the more compact the spot diagram, the smaller the aberration

[0126] Fig.21 This is a relative illumination diagram of the third embodiment under visible light 435-650nm. It can be seen from the figure that the relative illumination of the lens is greater than 60% when the horizontal viewing angle HFOV=37.5.

[0127] In summary, the advantages of the lens of the present invention are as follows:

[0128] First, the lens takes into account the various reliability requirements of automotive regulations and has high reliability. The first lens 01 is made of spherical glass material and has high hardness.

[0129] Second, the lens has a large image surface design and high pixels, supporting 4K-level vehicle-mounted sensor requirements.

[0130] Third, the lens has a large aperture of F1.7, which provides good low-light effects.

[0131] Fourth, the lens is highly manufacturable, has a small outer diameter, and a short overall length.

[0132] Fifth, the lens meets the automotive standard temperature drift requirements of -40℃ to 105℃, and has a non-thermal design.

[0133] Sixth, ghost images are taken into consideration in real time during the lens design process. Ghost images have low energy and occupy small pixels.

[0134] 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 imaging lens, characterized in that: The optical system 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 the optical axis from the object side to the image side, wherein: The object side surface of the first lens is convex, the image side surface of the first lens is concave, and the first lens has negative refractive power; The object side surface of the second lens is a convex surface, the image side surface of the second lens is a convex surface, and the second lens has a positive refractive power; The object side surface of the third lens is a concave surface, the image side surface of the third lens is a convex surface, and the third lens has a negative refractive power; The object side surface of the fourth lens is a convex surface, the image side surface of the fourth lens is a convex surface, and the fourth lens has a positive refractive power; The object side surface of the fifth lens is a concave surface, the image side surface of the fifth lens is a concave surface, and the fifth lens has a negative refractive power; The object side surface of the sixth lens is a concave surface, the image side surface of the sixth lens is a convex surface, and the sixth lens has a positive refractive power; The object side surface of the seventh lens is a convex surface, the image side surface of the seventh lens is a convex surface, and the seventh lens has positive refractive power.

2. The imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: D1 / T1≥6.5, and DR2 / R2≤0.5, wherein T1 is the center thickness of the first lens, D1 is the outer diameter of the first lens, DR2 is the aperture of the image side of the first lens, and R2 is the curvature radius of the image side of the first lens.

3. The imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: 0.8<f1 / f2<1.3, wherein f1 is the focal length of the first lens, and f2 is the focal length of the second lens.

4. The imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: -0.8>f3 / f4>-1.3, wherein f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens.

5. The imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Nd2>2.0, where Nd2 is the refractive index coefficient of the second lens.

6. The imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Vd3<50, where Vd3 is the Abbe coefficient of the third lens.

7. The imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Vd4>70, Nd4<1.6, wherein Vd4 is the Abbe coefficient of the third lens, Nd4 is the refractive index of the fourth lens, and the fourth lens is a positive lens; And the lens satisfies the following relationship: dn / dT<-8.5*10E-6 in the temperature range of -40°C-105°C, where dn / dT is the refractive index temperature coefficient of the material.

8. The imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Vd5<50, wherein Vd5 is the Abbe coefficient of the fifth lens.

9. The imaging lens according to claim 1, characterized in that: The fourth lens and the fifth lens are a cemented lens group, and the lens satisfies the following relationship: Vd4-Vd5>50, wherein Vd4 is the Abbe coefficient of the fourth lens, and Vd5 is the Abbe coefficient of the fifth lens.

10. The imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: Nd6>1.8, Nd7>1.8, wherein Nd6 is the refractive index coefficient of the sixth lens; Nd7 is the refractive index coefficient of the seventh lens.

Images