Optical lens

Abstract

The utility model discloses an optical lens. The optical lens 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 from an object plane to an image plane along an optical axis, the first lens is a negative-focal-power convex-concave lens, the second lens is a negative-focal-power concave-convex lens, the third lens is a positive-focal-power biconvex lens, and the seventh lens is a positive-focal-power biconvex lens. The fourth lens is a positive-focal-power biconvex lens, the fifth lens is a positive-focal-power biconvex lens, the sixth lens is a negative-focal-power biconcave lens or a negative-focal-power concave-flat lens, and the seventh lens is a positive-focal-power convex-concave lens; meanwhile, the focal length F of the optical lens and the distance TTL from the center of the optical axis of the object side face of the first lens to the image face are set, TTL / F is smaller than or equal to 5.5, and under the condition that it is guaranteed that the optical lens is small in size, the high pixel, the large aperture and the large angle are achieved, and the use requirements are met.

Description

Technical Field

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

[0002] With the improvement of the scientific and technological level, automobiles have gradually become indispensable consumer goods. Naturally, people's attention to driving safety has become higher and higher, and various assisted driving functions have emerged accordingly. With the rapid development of the Advanced Driver Assistance System (ADAS), in-vehicle lenses have a wider range of applications and developments. Although the existing optical in-vehicle lenses can basically meet the basic needs of large-field-of-view in-vehicle lenses, there are still many defects. Under the condition of dim weather, the picture clarity is not enough and it cannot be recognized more intelligently. In addition, when the lens is installed on a car, the miniaturization problem has to be considered. If the lens size is too large, there will be problems in the actual use of the lens. Therefore, the miniaturization of the lens is also one of the goals we pursue.

[0003] In view of this, it is necessary to provide a lens with high pixels, a large aperture, a large angle and miniaturization to solve the above technical problems. Summary of the Utility Model

[0004] The utility model provides an optical lens to meet the use requirements of high pixels, a large aperture, a large angle and miniaturization.

[0005] According to one aspect of the utility model, there is provided an optical 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 in sequence from the object plane to the image plane along the optical axis;

[0006] The first lens has a negative optical power, the second lens has a negative optical power, the third lens has a positive optical power, the fourth lens has a positive optical power, the fifth lens has a positive optical power, the sixth lens has a negative optical power, and the seventh lens has a positive optical power;

[0007] The surface of the lens on the side adjacent to the object surface is the object side surface, and the surface of the lens on the side adjacent to the image surface is the image side surface; the object side surface of the first lens bulges towards the object surface, and the image side surface of the first lens bulges towards the object surface; the object side surface of the second lens is concave towards the object surface, and the image side surface of the second lens is concave towards the object surface; the object side surface of the third lens bulges towards the object surface, and the image side surface of the third lens is concave towards the object surface; the object side surface of the fourth lens bulges towards the object surface, and the image side surface of the fourth lens is concave towards the object surface; the object side surface of the fifth lens bulges towards the object surface, and the image side surface of the fifth lens is concave towards the object surface; the object side surface of the sixth lens is concave towards the object surface, and the image side surface of the sixth lens bulges towards the object surface or the image side surface of the sixth lens is a plane; the object side surface of the seventh lens bulges towards the object surface, and the image side surface of the seventh lens bulges towards the object surface;

[0008] Wherein, the focal length of the optical lens is F, and the distance from the optical axis center of the object side surface of the first lens to the image surface is TTL, satisfying: TTL / F ≤ 5.5.

[0009] Optionally, the focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, and the focal length of the optical lens is F, where: -2 < f1 / F < 0, -20 < f2 / F < 0, 0 < f3 / F < 4, 0 < f4 / F < 3, 0 < f5 / F < 2, -2 < f6 / F < 0, 0 < f7 / F < 4.

[0010] Optionally, the focal length value of the cemented lens formed by cementing and fixing the fifth lens and the sixth lens is f56, and the focal length of the optical lens is F, where 5 ≤ |f56 / F| ≤ 10.

[0011] Optionally, the maximum field of view angle of the optical lens is FOV, the focal length of the optical lens is F, and the image height corresponding to the maximum field of view angle of the optical lens is H, where (FOV × F) / H ≥ 76.

[0012] Optionally, the distance from the optical axis center of the image side surface of the seventh lens to the image surface is BFL, and the distance from the optical axis center of the object side surface of the first lens to the image surface is TTL, where BFL / TTL ≥ 0.5.

[0013] Optionally, the entrance pupil diameter of the optical lens is ENPD, and the distance from the optical axis center of the object side surface of the first lens to the image surface is TTL, where ENPD / TTL ≥ 0.1.

[0014] Optionally, the refractive index of the first lens is n1, where: n1 ≥ 1.7.

[0015] Optionally, the radius of curvature of the object side surface of the first lens is R11, the radius of curvature of the image side surface of the first lens is R12, the radius of curvature of the object side surface of the second lens is R21, the radius of curvature of the image side surface of the second lens is R22, the central thickness of the first lens is d1, and the central thickness of the second lens is d2, where 0.8 ≤ R11 / (R12 + d1) ≤ 1.3, 0.8 ≤ R21 / (R22 + d2) ≤ 1.3, and -4.0 ≤ (R12 - R21) / (R12 + R21) ≤ 1.

[0016] Optionally, the radius of curvature of the object side surface of the first lens is R11, and the focal length of the optical lens is F, where: 0.5 < R11 / F < 2.

[0017] Optionally, the optical lens further includes a diaphragm; the diaphragm is located in the optical path between the third lens and the fourth lens.

[0018] In the technical solution of the embodiment of the present invention, the optical lens includes 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 surface to the image surface. By reasonably setting the optical power and surface shape of each lens, and simultaneously setting the focal length of the optical lens as F and the distance from the optical axis center of the object side surface of the first lens to the image surface as TTL, satisfying: TTL / F ≤ 5.5, it is ensured that the optical lens can meet the requirements of high pixels, large apertures, and large angles in the case of a small volume, meeting the usage requirements.

[0019] 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 invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic structural diagram of an optical lens provided in Embodiment 1 of the present invention;

[0022] Figure 2 It is a light fan diagram of an optical lens provided in Embodiment 1 of the present invention;

[0023] Figure 3An axial aberration curve graph of an optical lens provided in the first embodiment of the present utility model;

[0024] Figure 4 A field curvature and distortion curve graph of an optical lens provided in the first embodiment of the present utility model;

[0025] Figure 5 A structural schematic diagram of an optical lens provided in the second embodiment of the present utility model;

[0026] Figure 6 A ray fan diagram of an optical lens provided in the second embodiment of the present utility model;

[0027] Figure 7 An axial aberration curve graph of an optical lens provided in the second embodiment of the present utility model;

[0028] Figure 8 A field curvature and distortion curve graph of an optical lens provided in the second embodiment of the present utility model;

[0029] Figure 9 A structural schematic diagram of an optical lens provided in the third embodiment of the present utility model;

[0030] Figure 10 A ray fan diagram of an optical lens provided in the third embodiment of the present utility model;

[0031] Figure 11 An axial aberration curve graph of an optical lens provided in the third embodiment of the present utility model;

[0032] Figure 12 A field curvature and distortion curve graph of an optical lens provided in the third embodiment of the present utility model. Detailed implementation manners

[0033] In order to enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0034] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present utility model are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0035] Embodiment 1

[0036] Figure 1 As shown in the structural schematic diagram of an optical lens provided in Embodiment 1 of the present utility model, Figure 1 as shown, the optical lens 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 in sequence along the optical axis from the object plane to the image plane; the first lens 101 has a negative optical power, the second lens 102 has a negative optical power, the third lens 103 has a positive optical power, the fourth lens 104 has a positive optical power, the fifth lens 105 has a positive optical power, the sixth lens 106 has a negative optical power, and the seventh lens 107 has a positive optical power; the surface of the lens adjacent to the object plane is the object side surface, and the surface of the lens adjacent to the image plane is the image side surface; the object side surface of the first lens 101 protrudes towards the object plane, and the image side surface of the first lens 101 protrudes towards the object plane; the object side surface of the second lens 102 is recessed towards the object plane, and the image side surface of the second lens 102 is recessed towards the object plane; the object side surface of the third lens 103 protrudes towards the object plane, and the image side surface of the third lens 103 is recessed towards the object plane; the object side surface of the fourth lens 104 protrudes towards the object plane, and the image side surface of the fourth lens 104 is recessed towards the object plane; the object side surface of the fifth lens 105 protrudes towards the object plane, and the image side surface of the fifth lens 105 is recessed towards the object plane; the object side surface of the sixth lens 106 is recessed towards the object plane, and the image side surface of the sixth lens 106 protrudes towards the object plane or the image side surface of the sixth lens 106 is a plane; the object side surface of the seventh lens 107 protrudes towards the object plane, and the image side surface of the seventh lens 107 protrudes towards the object plane; wherein, the focal length of the optical lens is F, and the distance from the optical axis center of the object side surface of the first lens 101 to the image plane is TTL, satisfying: TTL / F ≤ 5.5.

[0037] Exemplarily, the optical power is equal to the difference between the image-space beam convergence and the object-space beam convergence, which characterizes the ability of an optical system to deflect light rays. The greater the absolute value of the optical power, the stronger the bending ability of the light rays; the smaller the absolute value of the optical power, the weaker the bending ability of the light rays. When the optical power is positive, the refraction of the light rays is convergent; when the optical power is negative, the refraction of the light rays is divergent. The optical power can be used to characterize a certain refracting surface of a lens (i.e., a surface of the lens), can be used to characterize a certain lens, or can be used to characterize a system formed by multiple lenses together (i.e., a lens group). In the optical lens provided in this embodiment, each lens can be fixed in a lens barrel ( Figure 1 not shown in the figure). The first lens 101 has a negative optical power, the second lens 102 has a negative optical power, the third lens 103 has a positive optical power, the fourth lens 104 has a positive optical power, the fifth lens 105 has a positive optical power, the sixth lens 106 has a negative optical power, and the seventh lens 104 has a positive optical power. At the same time, the surface shapes of the lenses are reasonably adjusted so that the optical power of the entire optical lens is distributed according to a certain ratio, ensuring the balance of the incident angle sizes of the front and rear lens groups, so as to reduce the sensitivity of the lens and improve the production possibility. At the same time, it can also ensure that the entire optical lens structure is compact and the integration of the optical lens is high. Further adjust the focal length F of the optical lens and the distance TTL from the optical axis center of the object side of the first lens 101 to the image plane to satisfy: TTL / F ≤ 5.5, effectively controlling the total length of the lens. Therefore, according to the embodiments of the present invention, a miniaturized optical lens can be obtained.

[0038] Optionally, 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 optical lens is F, where: -2 < f1 / F < 0, -20 < f2 / F < 0, 0 < f3 / F < 4, 0 < f4 / F < 3, 0 < f5 / F < 2, -2 < f6 / F < 0, 0 < f7 / F < 4.

[0039] Among them, the first lens 101 has a negative optical power, which is beneficial to expanding the field of view angle of the optical lens. The second lens 102 has a negative optical power and can share the negative optical power at the front end of the optical lens, thus helping to avoid excessive light deflection caused by the over-concentration of the optical power of the first lens 101 and reducing the difficulty of chromatic aberration correction of the optical lens. The third lens 103 has a positive optical power, which is beneficial to the smooth transition of light, facilitating the correction of astigmatism and field curvature, and improving the imaging quality of the optical lens. By controlling the focal length of the fourth lens 104, the optical power of the entire optical system can be reasonably distributed, which is beneficial to achieving temperature characteristics and ensuring good imaging quality of the lens under high and low temperature conditions. The fifth lens 105 has an appropriate positive optical power, which is beneficial to the smooth transition of light, facilitating the correction of astigmatism and field curvature, and improving the imaging quality of the optical lens. The sixth lens 106 has an appropriate negative optical power, which is beneficial to increasing the imaging area of the optical lens and at the same time balancing various aberrations generated by the fifth lens 105, improving the imaging quality of the optical lens. The seventh lens 107 has a short focal length, which helps to collect light, ensure the light passing amount, improve the relative illuminance, and enhance the brightness of the optical lens at the image plane. Ensure that the focal lengths of each lens meet the optical performance, and at the same time ensure that the structure of the optical lens is compact, reduce the lens size, and achieve miniaturized applications.

[0040] Optionally, the focal length value of the cemented lens formed by cementing and fixing the fifth lens 105 and the sixth lens 106 is f56, and the focal length of the optical lens is F, where 5 ≤ |f56 / F| ≤ 10.

[0041] Among them, the image side of the fifth lens 105 and the object side of the sixth lens 106 are cemented, so that the fifth lens 105 and the sixth lens 106 can be combined into a cemented lens. The use of a cemented lens can effectively reduce the air gap between the fifth lens 105 and the sixth lens 106, thereby reducing the overall length of the lens. In addition, the cemented lens can be used to minimize or eliminate chromatic aberration to fully correct various aberrations of the optical lens. On the premise of a compact structure, it can improve the resolution, optimize optical performance such as distortion and CRA, control the light path between the fifth lens 105 and the sixth lens 106, reduce aberrations caused by large angles, balance the aberrations of the optical lens, and improve the imaging quality of the optical lens; and it can reduce the light loss caused by reflection between lenses, improve the illuminance, thereby improving the image quality and enhancing the clarity of the lens imaging. In addition, the use of a cemented lens can also reduce the assembly components between the two lenses, simplify the assembly procedure in the lens manufacturing process, reduce costs, and reduce the tolerance sensitivity problems such as tilt / eccentricity generated during the assembly process of the lens unit, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0042] Optionally, the maximum field of view angle of the optical lens is FOV, the focal length of the optical lens is F, and the image height corresponding to the maximum field of view angle of the optical lens is H, where (FOV × F) / H ≥ 76.

[0043] Among them, when ignoring distortion, the relationship between the focal length F of the optical lens, the maximum field of view angle FOV, and the image height H is: F = H / tan(FOV). That is, at the same focal length value, the larger the image height, the larger the image height reflects the matching sensor size, and the larger the maximum field of view angle FOV; at the same image height, the larger the focal length value, the smaller the maximum field of view angle FOV; reasonably adjust the maximum field of view angle of the optical lens to FOV, the focal length of the optical lens to F, and the image height corresponding to the maximum field of view angle of the optical lens to H, satisfying (FOV × F) / H ≥ 76. At the same focal length value and matching the same size sensor, a large field of view angle meets the optical requirements of the optical lens.

[0044] Optionally, the distance from the optical axis center of the image side of the seventh lens 107 to the image plane is BFL, and the distance from the optical axis center of the object side of the first lens 101 to the image plane is TTL, where BFL / TTL ≥ 0.5.

[0045] Exemplarily, the distance from the optical axis center of the image side of the seventh lens 107 to the image plane can be understood as the back focal length of the optical lens, and the distance from the optical axis center of the object side of the first lens 101 to the image plane can be understood as the total length of the optical lens. By reasonably setting the relationship between the back focal length and the total length of the optical lens, in the embodiments of the present invention, by setting BFL / TTL ≥ 0.5, it can ensure that the entire optical lens structure is compact. On the basis of realizing miniaturization, the back focal length is long, which is beneficial to the assembly of the module, and the integration degree of the optical lens is high.

[0046] Optionally, the entrance pupil diameter of the optical lens is ENPD, and the distance from the optical axis center of the object side of the first lens 101 to the image plane is TTL, where ENPD / TTL ≥ 0.1.

[0047] Among them, the larger the entrance pupil diameter of the optical lens, the larger the light passing amount, and a small FNO is realized. The entrance pupil diameter ENPD of the optical lens and the distance TTL from the optical axis center of the object side of the first lens to the image plane satisfy ENPD / TTL ≥ 0.1, which is beneficial to realizing the large aperture characteristic and providing more incident light for the optical lens.

[0048] Optionally, the refractive index of the first lens 101 is n1, where: n1 ≥ 1.7.

[0049] Among them, the refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium, mainly used to describe the refractive ability of the material to light, and the refractive indices of different materials are different. In this embodiment, by matching the refractive indices of the lenses in the optical lens, it is beneficial to realize the miniaturized design of the optical lens. At the same time, the balance of the incident angle sizes of the front and rear lens groups can be ensured to reduce the sensitivity of the lens and improve the production possibility.

[0050] Optionally, the curvature radius of the object side surface of the first lens 101 is R11, the curvature radius of the image side surface of the first lens 101 is R12, the curvature radius of the object side surface of the second lens 102 is R21, the curvature radius of the image side surface of the second lens 102 is R22, the central thickness of the first lens 101 is d1, and the central thickness of the second lens 102 is d2, where 0.8 ≤ R11 / (R12 + d1) ≤ 1.3, 0.8 ≤ R21 / (R22 + d2) ≤ 1.3, -4.0 ≤ (R12 - R21) / (R12 + R21) ≤ 1.

[0051] Among them, by adjusting the surface shapes of the first lens 101 and the second lens 102, through special lens shape settings, the shape is close to a concentric circle, so that there is an optical path difference between the peripheral light and the central light, the central light is diverged, enters the rear optical system, and the front aperture of the lens is reduced, and the volume is reduced, which is beneficial to miniaturization and cost reduction. At the same time, adjusting the image side surface of the first lens 101 and the object side surface of the second lens 102 to satisfy: -4.0 ≤ (R12 - R21) / (R12 + R21) ≤ 1 can correct the aberration of the optical lens, and ensure that when the light emitted from the first lens 101 is incident on the first surface of the second lens 102, the incident light is relatively gentle, thereby reducing the tolerance sensitivity of the optical system.

[0052] Optionally, the curvature radius of the object side surface of the first lens 101 is R11, and the focal length of the optical lens is F, where: 0.5 < R11 / F < 2.

[0053] Among them, controlling the ratio of the curvature radius R11 of the object side surface of the first lens 101 to the focal length F of the optical lens to be greater than 0.5 is beneficial to increasing the field of view angle of the optical lens, so as to meet the large-range shooting requirements; controlling the ratio of the curvature radius R11 of the object side surface of the first lens 101 to the focal length F of the optical lens to be less than 2 is beneficial to reducing the effective aperture of the lens and realizing miniaturization.

[0054] Optionally, the optical lens further includes a diaphragm 10; the diaphragm is located in the optical path between the third lens 103 and the fourth lens 104.

[0055] Among them, by adding a diaphragm 10 near the image side of the third lens 103, the generation of astigmatism of the optical lens can be reduced, and it is beneficial to converge the light entering the optical system, reduce the aperture of the rear port of the optical lens, and is beneficial to improving the imaging quality.

[0056] Optionally, a filter 11 is further provided along the object plane to the image plane; the filter 11 is located on the image side of the seventh lens 107.

[0057] Among them, by providing a filter 11 on the image side of the seventh lens 107, unnecessary stray light can be filtered out, thereby improving the image quality of the optical lens. For example, by filtering out infrared light during the day through the filter 11, the imaging quality of the optical lens can be improved.

[0058] Exemplarily, Table 1 details the specific optical physical parameters of each lens in the optical lens provided in the first embodiment of the present invention in a feasible implementation manner. The optical lens in Table 1 corresponds to Figure 1 the optical lens shown.

[0059] Table 1 Design values of optical parameters of the optical lens

[0060]

[0061]

[0062] Among them, the surface numbers are numbered according to the surface order of each lens. For example, the surface number "S1" represents the object side of the first lens 101, the surface number "S2" represents the image side of the first lens 101, the surface number "S12" represents the image side of the sixth lens 106, and so on; "STO" represents the diaphragm 10 of the lens; the radius of curvature represents the degree of curvature of the lens surface. A positive value represents that the surface bends towards the object side, and the center of the circle is close to the image side. A negative value represents that the surface bends towards the image side, and the center of the circle is close to the object side. Among them, "PL" represents that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the material (nd) represents the refractive index, that is, the ability of the material between the current surface and the next surface to deflect light. A space represents that the current position is air and the refractive index is 1; the material (vd) represents the Abbe number, that is, the dispersion characteristics of the material between the current surface and the next surface to light. A space represents that the current position is air. The semi-diameter represents the semi-aperture of the lens.

[0063] In this embodiment, the first lens 101 and the seventh lens 107 are aspherical lenses. The aspherical conic coefficient can be defined by the following aspherical formula, but is not limited to the following representation methods:

[0064]

[0065] In the formula, Z is the distance sagitta from the vertex of the aspheric surface when the aspheric surface is at a position with a height of y along the optical axis direction; c = 1 / R, where R represents the paraxial curvature radius of the mirror surface; K is the conic coefficient; A, B, C, D, and E are the coefficients of the 4th, 6th, 8th, 10th, 12th, and 14th order terms of the aspheric polynomial, respectively.

[0066] Exemplarily, Table 2 details the aspheric coefficients of each lens in this embodiment in a feasible implementation manner.

[0067] Table 2 A design value of the aspheric coefficients in the optical lens

[0068]

[0069] Among them, -1.75E-03 indicates that the coefficient A of the surface serial number S1 is -1.75×10 -3 , and so on.

[0070] Figure 2 The light fan diagram of an optical lens provided in the first embodiment of the present invention is shown in Figure 2 As shown, the imaging ranges of different wavelength lights (0.436μm, 0.486μm, 0.546μm, 0.588μm, and 0.656μm) at different field angles of this optical lens are all within 30μm and the curves are very concentrated, ensuring that the aberration in different field regions is small, that is, it shows that this optical lens corrects the aberration of the optical system well.

[0071] Figure 3 The axial aberration curve diagram of an optical lens provided in the first embodiment of the present invention is shown in Figure 2 As shown, the aberrations of this optical lens at different wavelengths (0.436μm, 0.486μm, 0.546μm, 0.588μm, and 0.656μm) are all within 0.02mm, and the curves of different wavelengths are relatively concentrated, indicating that the axial aberration of this optical lens is very small. Thus, it can be known that the optical lens provided in the first embodiment of the present invention can correct the aberration well.

[0072] Figure 4 The field curvature and distortion curve diagram of an optical lens provided in the first embodiment of the present invention is shown in Figure 4 As shown, in the field curvature curve diagram, the horizontal coordinate represents the magnitude of the field curvature, with the unit of mm; the vertical coordinate represents the normalized image height, without a unit; where T represents the meridian and S represents the sagittal; from Figure 4 It can be seen that the field curvature of the optical lens provided in this embodiment is effectively controlled from the light with a wavelength of 436nm to the light with a wavelength of 656nm, that is, when imaging, the image quality at the center and the image quality at the periphery have a small difference. In the distortion curve diagram, the horizontal coordinate represents the magnitude of the distortion, with the unit of %; the vertical coordinate represents the normalized image height, without a unit; fromFigure 4 It can be seen that the distortion of the optical lens provided in this embodiment is well corrected, the imaging distortion is small, meeting the requirements of low distortion and conforming to the general level of optical lenses.

[0073] Embodiment 2

[0074] Figure 5 As shown in the schematic structural diagram of an optical lens provided in Embodiment 2 of the present invention, Figure 5 as shown, the optical lens includes: a first lens 201, a second lens 202, a third lens 203, a fourth lens 204, a fifth lens 205, a sixth lens 206, and a seventh lens 207 arranged in sequence along the optical axis from the object plane to the image plane; the first lens 201 has a negative optical power, the second lens 202 has a negative optical power, the third lens 203 has a positive optical power, the fourth lens 204 has a positive optical power, the fifth lens 205 has a positive optical power, the sixth lens 206 has a negative optical power, and the seventh lens 207 has a positive optical power; the surface of the lens adjacent to the object plane side is the object side surface, and the surface of the lens adjacent to the image plane side is the image side surface; the object side surface of the first lens 201 bulges towards the object plane, and the image side surface of the first lens 201 bulges towards the object plane; the object side surface of the second lens 202 depresses towards the object plane, and the image side surface of the second lens 202 depresses towards the object plane; the object side surface of the third lens 203 bulges towards the object plane, and the image side surface of the third lens 203 depresses towards the object plane; the object side surface of the fourth lens 204 bulges towards the object plane, and the image side surface of the fourth lens 204 depresses towards the object plane; the object side surface of the fifth lens 205 bulges towards the object plane, and the image side surface of the fifth lens 205 depresses towards the object plane; the object side surface of the sixth lens 206 depresses towards the object plane, and the image side surface of the sixth lens 206 is a plane; the object side surface of the seventh lens 207 bulges towards the object plane, and the image side surface of the seventh lens 207 bulges towards the object plane; wherein, the focal length of the optical lens is F, and the distance from the optical axis center of the object side surface of the first lens 201 to the image plane is TTL, satisfying: TTL / F ≤ 5.5.

[0075] Among them, the optical power, focal length of each lens, and the position setting of the optical lens aperture are the same as those in Embodiment 1, and will not be elaborated here.

[0076] Exemplarily, Table 3 details the specific optical physical parameters of each lens in the optical lens provided in Embodiment 2 of the present invention in a feasible implementation manner. The optical lens in Table 3 corresponds to Figure 5 the optical lens shown.

[0077] Table 3 Design values of the optical parameters of the optical lens

[0078] Surface Serial Number Surface Type Radius of Curvature Thickness Material (nd) Material (vd) 1 Aspherical Surface 5.77 2.20 1.81 41 2 Aspherical Surface 2.58 3.25 3 Spherical Surface -4.91 2.13 1.87 41 4 Spherical Surface -6.65 0.10 5 Spherical Surface 21.73 2.06 1.91 35.2 6 Spherical Surface -44.00 0.69 STO (Diaphragm) PL Infinity 0.42 8 Spherical Surface 11.57 5.00 1.6 65.5 9 Spherical Surface -9.86 0.10 10 Spherical Surface 14.07 2.20 1.5 81.6 11 Spherical Surface -5.32 1.30 1.85 23.8 12 Spherical Surface Infinity 0.60 13 Aspherical Surface 11.97 3.90 1.87 41 14 Aspherical Surface 52.31 1.00 15 Spherical Surface Infinity 0.80 1.52 64 16 Spherical Surface Infinity 1.44 IMA Infinity

[0079] Among them, the surface numbers are numbered according to the surface order of each lens. For example, the surface number "S1" represents the object side surface of the first lens 201, the surface number "S2" represents the image side surface of the first lens 201, the surface number "S12" represents the image side surface of the sixth lens 206, and so on; "STO" represents the aperture 10 of the lens; the radius of curvature represents the degree of curvature of the lens surface. A positive value represents that the surface bends towards the object side, and the center of the circle is close to the image side. A negative value represents that the surface bends towards the image side, and the center of the circle is close to the object side. Among them, "PL" represents that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the material (nd) represents the refractive index, that is, the ability of the material between the current surface and the next surface to deflect light. A space represents that the current position is air and the refractive index is 1; the material (vd) represents the Abbe number, that is, the dispersion characteristics of the material between the current surface and the next surface to light. The semi-diameter represents the semi-aperture of the lens.

[0080] In this embodiment, the first lens 201 and the seventh lens 207 are aspherical lenses. The aspherical conic coefficient can be defined by the following aspherical formula, but is not limited to the following representation:

[0081]

[0082] In the formula, Z is the sagitta, the distance from the vertex of the aspherical surface to the aspherical surface along the optical axis at a position with a height of y; c = 1 / R, where R represents the paraxial radius of curvature of the mirror surface; K is the conic coefficient; A, B, C, D, and E are the coefficients of the 4th, 6th, 8th, 10th, 12th, and 14th order terms of the aspherical polynomial, respectively.

[0083] Exemplarily, Table 4 details the aspherical coefficients of each lens in this embodiment in a feasible implementation manner.

[0084] Table 4 A design value of the aspherical coefficient in the optical lens

[0085] Serial Number A B C D E F 1 -1.77E-03 -3.42E-05 7.99E-07 9.01E-08 -4.23E-09 6.20E-11 2 -4.93E-03 -5.34E-04 8.14E-05 -1.33E-05 9.77E-07 -7.50E-09

[0086] Among them, -1.77E-03 means that the coefficient A of the surface number S1 is -1.77×10 -3 , and so on.

[0087] Figure 6 This is the light fan diagram of an optical lens provided in the second embodiment of the present invention. As Figure 6As shown, the imaging ranges of light rays with different wavelengths (0.436 μm, 0.486 μm, 0.546 μm, 0.588 μm, and 0.656 μm) at different field angles of the optical lens are all within 30 μm and the curves are very concentrated, ensuring that the aberration in different field regions is small, which also means that the optical lens corrects the aberration of the optical system well.

[0088] Figure 7 This is the axial aberration curve diagram of an optical lens provided in the second embodiment of the present invention. As Figure 7 shown, the aberrations of the optical lens at different wavelengths (0.436 μm, 0.486 μm, 0.546 μm, 0.588 μm, and 0.656 μm) are all within 0.02 mm, and the curves at different wavelengths are relatively concentrated, indicating that the axial aberration of the optical lens is very small. Thus, it can be known that the optical lens provided in the second embodiment of the present invention can correct the aberration well.

[0089] Figure 8 This is the field curvature and distortion curve diagram of an optical lens provided in the second embodiment of the present invention. As Figure 8 shown, the horizontal coordinate in the field curvature curve diagram represents the magnitude of field curvature, with the unit of mm; the vertical coordinate represents the normalized image height, without a unit; where T represents meridian and S represents sagittal; from Figure 8 it can be seen that the field curvature of the optical lens provided in this embodiment is effectively controlled from the light with a wavelength of 436 nm to the light with a wavelength of 656 nm, that is, during imaging, the image quality at the center and the image quality at the periphery have a small difference. In the distortion curve diagram, the horizontal coordinate represents the magnitude of distortion, with the unit of %; the vertical coordinate represents the normalized image height, without a unit; from Figure 8 it can be seen that the distortion of the optical lens provided in this embodiment is well corrected, the imaging distortion is small, meeting the requirements of low distortion and conforming to the general level of optical lenses.

[0090] Embodiment Three

[0091] Figure 9 This is the structural schematic diagram of an optical lens provided in the third embodiment of the present invention. As Figure 9As shown in the figure, the optical lens includes: a first lens 301, a second lens 302, a third lens 303, a fourth lens 304, a fifth lens 305, a sixth lens 306, and a seventh lens 307 arranged in sequence along the optical axis from the object plane to the image plane; the first lens 301 has a negative optical power, the second lens 302 has a negative optical power, the third lens 303 has a positive optical power, the fourth lens 304 has a positive optical power, the fifth lens 305 has a positive optical power, the sixth lens 306 has a negative optical power, and the seventh lens 307 has a positive optical power; the surface of the lens adjacent to the object plane is the object side surface, and the surface of the lens adjacent to the image plane is the image side surface; the object side surface of the first lens 301 protrudes towards the object plane, and the image side surface of the first lens 301 protrudes towards the object plane; the object side surface of the second lens 302 is recessed towards the object plane, and the image side surface of the second lens 302 is recessed towards the object plane; the object side surface of the third lens 303 protrudes towards the object plane, and the image side surface of the third lens 303 is recessed towards the object plane; the object side surface of the fourth lens 304 protrudes towards the object plane, and the image side surface of the fourth lens 304 is recessed towards the object plane; the object side surface of the fifth lens 305 protrudes towards the object plane, and the image side surface of the fifth lens 305 is recessed towards the object plane; the object side surface of the sixth lens 306 is recessed towards the object plane, and the image side surface of the sixth lens 306 protrudes towards the object plane; the object side surface of the seventh lens 307 protrudes towards the object plane, and the image side surface of the seventh lens 307 protrudes towards the object plane; wherein, the focal length of the optical lens is F, and the distance from the optical axis center of the object side surface of the first lens 301 to the image plane is TTL, satisfying: TTL / F ≤ 5.5.

[0092] Among them, the optical power, focal length, and the position setting of the optical diaphragm of each lens are the same as those in the first embodiment, and will not be elaborated here.

[0093] Exemplarily, Table 5 details the specific optical physical parameters of each lens in the optical lens provided in the first embodiment of the present invention in a feasible implementation manner. The optical lens in Table 5 corresponds to Figure 9 the optical lens shown in the figure.

[0094] Table 5 Design values of the optical parameters of the optical lens

[0095] Surface Serial Number Surface Type Radius of Curvature Thickness Material (nd) Material (vd) 1 Aspherical Surface 5.65 2.20 1.81 41 2 Aspherical Surface 2.56 3.59 3 Spherical Surface -4.97 2.16 1.88 39 4 Spherical Surface -6.52 0.10 5 Spherical Surface 20.32 2.06 1.88 39 6 Spherical Surface -43.16 0.62 STO (Diaphragm) PL Infinity 0.42 8 Spherical Surface 11.38 5.00 1.6 65.5 9 Spherical Surface -10.18 0.10 10 Spherical Surface 14.10 2.20 1.5 81.6 11 Spherical Surface -5.24 1.30 1.85 23.8 12 Spherical Surface 130.00 0.56 13 Aspherical Surface 12.60 3.76 1.88 39 14 Aspherical Surface 71.89 1.00 15 Spherical Surface Infinity 0.80 1.52 64 16 Spherical Surface Infinity 1.28 IMA Infinity

[0096] Among them, the surface serial numbers are numbered according to the surface order of each lens. For example, the surface serial number "S1" represents the object side surface of the first lens 301, the surface serial number "S2" represents the image side surface of the first lens 301, the surface serial number "S12" represents the image side surface of the sixth lens 306, and so on; "STO" represents the aperture stop 10 of the lens; the radius of curvature represents the degree of curvature of the lens surface. A positive value indicates that the surface bends towards the object side, and the center of the circle is close to the image side. A negative value indicates that the surface bends towards the image side, and the center of the circle is close to the object side. Among them, "PL" represents that the surface is a plane, and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the material (nd) represents the refractive index, that is, the ability of the material between the current surface and the next surface to refract light. A space represents that the current position is air, and the refractive index is 1; the material (vd) represents the Abbe number, that is, the dispersion characteristic of the material between the current surface and the next surface to light. The semi-diameter represents the semi-aperture of the lens.

[0097] In this embodiment, the first lens 301 and the seventh lens 307 are aspherical lenses. The aspherical conic coefficient can be defined by the following aspherical formula, but is not limited to the following representation:

[0098]

[0099] In the formula, Z is the distance sagitta from the vertex of the aspherical surface at the position with height y along the optical axis direction; c = 1 / R, where R represents the paraxial radius of curvature of the mirror surface; K is the conic coefficient; A, B, C, D, and E are the coefficients of the 4th, 6th, 8th, 10th, 12th, and 14th order terms of the aspherical polynomial respectively.

[0100] Exemplarily, Table 6 details the aspherical coefficients of each lens in this embodiment in a feasible implementation manner.

[0101] Table 6 A design value of the aspherical coefficient in the optical lens

[0102] Serial Number A B C D E F 1 -1.80E-03 -3.78E-05 6.43E-07 9.07E-08 -4.15E-09 6.29E-11 2 -4.74E-03 -5.50E-04 8.76E-05 -1.37E-05 9.38E-07 -1.02E-08

[0103] Among them, -1.80E-03 means that the coefficient A of the surface with serial number S1 is -1.80 * 10 -3 , and so on.

[0104] Figure 10 This is the light fan diagram of an optical lens provided in the third embodiment of the present invention. As Figure 10As shown, the imaging ranges of light rays with different wavelengths (0.436μm, 0.486μm, 0.546μm, 0.588μm, and 0.656μm) at different field angles of this optical lens are all within 30μm and the curves are very concentrated, ensuring that the aberrations in different field regions are small, which also indicates that this optical lens corrects the aberrations of the optical system well.

[0105] Figure 11 This is the axial aberration curve graph of an optical lens provided in the third embodiment of the present invention. As Figure 11 shown, the aberrations of this optical lens at different wavelengths (0.436μm, 0.486μm, 0.546μm, 0.588μm, and 0.656μm) are all within 0.02mm, and the curves of different wavelengths are relatively concentrated, indicating that the axial aberration of this optical lens is very small. Thus, it can be known that the optical lens provided in the third embodiment of the present invention can correct aberrations well.

[0106] Figure 12 This is the field curvature and distortion curve graph of an optical lens provided in the third embodiment of the present invention. As Figure 12 shown, the horizontal coordinate in the field curvature curve graph represents the magnitude of the field curvature, with the unit of mm; the vertical coordinate represents the normalized image height, without a unit; where T represents meridional and S represents sagittal; From Figure 12 it can be seen that for the optical lens provided in this embodiment, from the light with a wavelength of 436nm to the light with a wavelength of 656nm, the field curvature is effectively controlled, that is, during imaging, the image quality at the center and the image quality at the periphery have a small difference. In the distortion curve graph, the horizontal coordinate represents the magnitude of the distortion, with the unit of %; the vertical coordinate represents the normalized image height, without a unit; From Figure 12 it can be seen that the distortion of the optical lens provided in this embodiment is well corrected, the imaging distortion is small, meeting the requirement of low distortion and conforming to the general level of optical lenses.

[0107] To more clearly illustrate the above embodiments, Table 7 details the specific optical physical parameters of each lens in the optical lenses provided in the first to third embodiments of the present invention and other feasible optical physical parameters.

[0108] Table 7 Design values of the optical physical parameters of the optical lens

[0109] Example 1 Example 2 Example 3 Lower Limit Upper Limit (FOV × F) / H 76.319 76.953 76.835 76.000 TTL / H / FOV 1.325 1.314 1.316 1.4 TTL / F 5.340 5.300 5.306 5.5 BFL / F 0.591 0.631 0.605 0.500 ENPD / TTL 0.114 0.114 0.114 0.100 f1 / F -1.628 -1.630 -1.655 -2.000 0 f2 / F -10.870 -9.636 -13.283 -20.000 0 f3 / F 3.116 3.139 3.085 0 4 f4 / F 1.922 1.880 1.900 0 3 f5 / F 1.500 1.569 1.556 0 2 f6 / F -1.155 -1.213 -1.146 -2 0 f7 / F 3.625 3.305 3.262 0 4 |f5 / f6| 1.298 1.294 1.358 0.5 2 |f56 / F| 7.366 6.933 5.500 5 10 R1 / (R2 + d1) 1.213 1.206 1.187 0.8 1.3 R3 / (R4 + d2) 1.100 1.084 1.139 0.8 1.30 R1 / F 1.141 1.125 1.103 0.5 2 (R2 - R3) / (R2 + R3) -3.134 -3.228 -3.124 -4 1

[0110] The above specific implementation manners do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An optical lens, characterized in that, Including: A first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens are arranged in sequence along the optical axis from the object plane to the image plane; The first lens has a negative optical power, the second lens has a negative optical power, the third lens has a positive optical power, the fourth lens has a positive optical power, the fifth lens has a positive optical power, the sixth lens has a negative optical power, and the seventh lens has a positive optical power; The surface of the lens adjacent to the object plane side is the object side surface, and the surface of the lens adjacent to the image plane side is the image side surface; the object side surface of the first lens bulges towards the object plane, and the image side surface of the first lens bulges towards the object plane; the object side surface of the second lens depresses towards the object plane, and the image side surface of the second lens depresses towards the object plane; the object side surface of the third lens bulges towards the object plane, and the image side surface of the third lens depresses towards the object plane; the object side surface of the fourth lens bulges towards the object plane, and the image side surface of the fourth lens depresses towards the object plane; the object side surface of the fifth lens bulges towards the object plane, and the image side surface of the fifth lens depresses towards the object plane; the object side surface of the sixth lens depresses towards the object plane, and the image side surface of the sixth lens bulges towards the object plane or the image side surface of the sixth lens is a plane; the object side surface of the seventh lens bulges towards the object plane, and the image side surface of the seventh lens bulges towards the object plane; Wherein, the focal length of the optical lens is F, and the distance from the optical axis center of the object side surface of the first lens to the image plane is TTL, satisfying: TTL / F ≤ 5.

5.

2. The optical lens according to claim 1, wherein 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 optical lens is F, where: -2 < f1 / F < 0, -20 < f2 / F < 0, 0 < f3 / F < 4, 0 < f4 / F < 3, 0 < f5 / F < 2, -2 < f6 / F < 0, 0 < f7 / F < 4.

3. The optical lens according to claim 1, characterized in that, The focal length value of the cemented lens composed of the fifth lens and the sixth lens cemented and fixed is f56, and the focal length of the optical lens is F, where 5 ≤ |f56 / F| ≤ 10.

4. The optical lens according to claim 1, wherein The maximum field of view angle of the optical lens is FOV, the focal length of the optical lens is F, and the image height corresponding to the maximum field of view angle of the optical lens is H, where (FOV × F) / H ≥ 76.

5. The optical lens according to claim 1, characterized in that, The distance from the optical axis center of the image side surface of the seventh lens to the image plane is BFL, and the distance from the optical axis center of the object side surface of the first lens to the image plane is TTL, where BFL / TTL ≥ 0.

5.

6. The optical lens according to claim 1, characterized in that, The entrance pupil diameter of the optical lens is ENPD, and the distance from the optical axis center of the object side surface of the first lens to the image plane is TTL, where ENPD / TTL ≥ 0.

1.

7. The optical lens according to claim 1, wherein The refractive index of the first lens is n1, where: n1 ≥ 1.

7.

8. The optical lens according to claim 1, wherein, The radius of curvature of the object side surface of the first lens is R11, the radius of curvature of the image side surface of the first lens is R12, the radius of curvature of the object side surface of the second lens is R21, the radius of curvature of the image side surface of the second lens is R22, the central thickness of the first lens is d1, and the central thickness of the second lens is d2, where 0.8 ≤ R11 / (R12 + d1) ≤ 1.3, 0.8 ≤ R21 / (R22 + d2) ≤ 1.3, and -4.0 ≤ (R12 - R21) / (R12 + R21) ≤ 1.

9. The optical lens according to claim 1, wherein The radius of curvature of the object side surface of the first lens is R11, and the focal length of the optical lens is F, where: 0.5 < R11 / F < 2.

10. The optical lens according to claim 1, characterized in that, The optical lens further includes a diaphragm; the diaphragm is located in the optical path between the third lens and the fourth lens.

Images