Optical lens

Abstract

The invention discloses an optical 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 from an object plane to an image plane along an optical axis, the first lens has negative focal power, the second lens has negative focal power, the third lens has positive focal power, the fourth lens has positive focal power, the fifth lens has negative focal power, the sixth lens has positive focal power, and the seventh lens has negative focal power. The fifth lens has positive focal power, the sixth lens has negative focal power, and the seventh lens has positive focal power. According to the optical lens provided by the embodiment of the invention, the seven lenses are adopted, and the focal power and the surface type of each lens are distributed, so that the total optical length of the lens is within 30mm, the aperture number is less than 1.65, the imaging requirement in a dark environment can be met, the imaging is clear, an imaging chip with more than 8 million pixels can be matched, stable high and low temperature resolution can be ensured, and the image quality is improved. The optical lens which is miniaturized, high in pixel, high in definition, large in aperture, high in relative illumination, large in field angle and weak in ghost image is realized.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to an optical lens. Background Art

[0002] With the development of autonomous driving functions, automotive lenses, as key components of autonomous driving assistance systems, have also seen rapid development, and the requirements for such lenses have become increasingly higher. Automotive optical lenses are key components for autonomous driving assistance systems to obtain external information, and higher requirements have been placed on the performance and structure of optical lenses used for forward vision. For example, forward vision optical lenses are required to have high resolution, large field of view, and miniaturization, and at the same time have large apertures, high relative illumination, and high resolution to meet the needs of automotive applications.

[0003] However, most of the existing automotive optical lenses are difficult to meet these requirements. For example, existing automotive optical lenses cannot simultaneously meet the requirements of high resolution and miniaturization; although existing automotive optical lenses can achieve a resolution of one million pixels, the lens aberrations such as chromatic aberration, astigmatism, and distortion are relatively serious; existing automotive optical lenses have low light transmission capabilities and cannot adapt to darker environments such as night or rainy days; existing automotive optical lenses cannot simultaneously meet the requirements of large aperture and high resolution; existing automotive optical lenses cannot simultaneously meet the requirements of small aperture and weak ghost images, etc. Summary of the invention

[0004] The present invention provides an optical lens to realize an optical lens which can take into account miniaturization, high pixel and high definition, large aperture, high relative illumination, large field angle and weak ghost image.

[0005] The present invention provides an optical lens, comprising 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 an object plane to an image plane along an optical axis;

[0006] The first lens has negative optical power, and its object side surface is convex, and its image side surface is concave;

[0007] The second lens has negative optical power, and its object side surface is concave, and its image side surface is concave;

[0008] The third lens has positive refractive power, and its object side surface is convex, and its image side surface is convex;

[0009] The fourth lens has positive refractive power, and its object side surface is convex, and its image side surface is convex;

[0010] The fifth lens has positive refractive power, and its image side surface is convex, and its image side surface is convex;

[0011] The sixth lens has negative optical power, its object side surface is concave, and its image side surface is convex;

[0012] The seventh lens has positive refractive power, and its object side surface is convex, and its image side surface is convex.

[0013] Optionally, the focal length of the optical lens is F, 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, and the focal length of the seventh lens is f7;

[0014] -2 <f1 / F<0;-3<f2 / F<0;0<f3 / F<2;0<f4 / F<3;

[0015] 0 <f5 / F<2;-2<f6 / F<0;0<f7 / F<3.5。

[0016] Optionally, the focal length of the optical lens is F, and the total optical length of the optical lens is TTL;

[0017] TTL / F<5.5.

[0018] Optionally, the fifth lens and the sixth lens form a cemented lens group.

[0019] Optionally, the focal length of the cemented lens group is f56, and the focal length of the optical lens is F;

[0020] 10≤|f56 / F|≤15.

[0021] Optionally, the optical lens further includes a diaphragm;

[0022] The aperture stop is located in an optical path between the third lens and the fourth lens.

[0023] Optionally, the total optical length of the optical lens is TTL, and the image height corresponding to the maximum field angle of the optical lens is H;

[0024] 6<TTL / H<7.

[0025] Optionally, the optical back focus of the optical lens is BFL, and the total optical length of the optical lens is TTL;

[0026] BFL / TTL>1.0.

[0027] Optionally, the entrance pupil diameter of the optical lens is ENPD, and the total optical length of the optical lens is TTL;

[0028] ENPD / TTL≥0.1.

[0029] Optionally, the refractive index of the first lens is Nd1, where Nd1≥1.7.

[0030] Optionally, the focal length of the fifth lens is f5, and the focal length of the sixth lens is f6;

[0031] 0.5<|f5 / f6|<1.5.

[0032] Optionally, the focal length of the second lens is f2, and the focal length of the seventh lens is f7;

[0033] -1<f2 / f7<-0.7.

[0034] Optionally, the Abbe number of the fifth lens is Vd5, and the refractive index is Nd5;

[0035] The Abbe number of the sixth lens is Vd6, and the refractive index is Nd6;

[0036] 3<Vd5 / Vd6<3.5; 0.8<Nd5 / Nd6<0.9.

[0037] Optionally, a central curvature radius of the object side surface of the first lens is R1, a central curvature radius of the image side surface of the first lens is R2, and a central thickness of the first lens is d1;

[0038] 0.8≤R1 / (R2+d1)≤1.5.

[0039] Optionally, the central curvature radius of the object side surface of the second lens is R3, the central curvature radius of the image surface of the seventh lens is R13, and the focal length of the optical lens is F;

[0040] -5.5<R3 / F<-4.5; 6<R13 / F<7.

[0041] Optionally, the central curvature radius of the object side surface of the first lens is R1, and the focal length of the optical lens is F;

[0042] 0.5<R1 / F<1.5.

[0043] The optical lens provided in the embodiment of the present invention adopts seven lenses. By reasonably allocating the optical power and surface shape of each lens, the total optical length of the lens is within 30 mm and the aperture number is below 1.65. It can meet the imaging needs of darker environments and has clear imaging. It can match imaging chips with more than 8 million pixels and can ensure stable high and low temperature resolution, thereby realizing an optical lens that can take into account miniaturization, high pixels and high definition, large aperture, high relative illumination, large field of view and weak ghost images.

[0044] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 A schematic diagram of the structure of an optical lens provided by an embodiment of the present invention;

[0047] Figure 2 A schematic diagram of the structure of another optical lens provided by an embodiment of the present invention;

[0048] Figure 3 A schematic diagram of the structure of another optical lens provided by an embodiment of the present invention;

[0049] Figure 4 A light fan diagram of the optical lens provided in the first embodiment of the present invention;

[0050] Figure 5 An axial aberration curve diagram of the optical lens provided in Embodiment 1 of the present invention;

[0051] Figure 6 A field curvature distortion diagram of the optical lens provided in Embodiment 1 of the present invention;

[0052] Figure 7 A light fan diagram of the optical lens provided in the second embodiment of the present invention;

[0053] Figure 8 An axial aberration curve diagram of the optical lens provided in Embodiment 2 of the present invention;

[0054] Fig. 9 A field curvature distortion diagram of the optical lens provided in the second embodiment of the present invention;

[0055] Fig.10 A light fan diagram of the optical lens provided in the third embodiment of the present invention;

[0056] Fig.11 Axial aberration curve diagram of the optical lens provided in Embodiment 3 of the present invention;

[0057] Fig.12 This is a field curvature distortion diagram of the optical lens provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0058] In order to enable those skilled in the art to better understand the scheme of the present invention, 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. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0059] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention 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 inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0060] Figure 1 A schematic diagram of the structure of an optical lens provided by an embodiment of the present invention, Figure 2 A schematic diagram of the structure of another optical lens provided by an embodiment of the present invention, Figure 3 A schematic diagram of the structure of another optical lens provided by an embodiment of the present invention is shown in FIG. Figure 1-Figure 3 As shown, the optical lens provided by the embodiment of the present invention includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a seventh lens L7 which are arranged in sequence from the object plane to the image plane along the optical axis.

[0061] The first lens L1 has negative refractive power, and its object-side surface is convex and its image-side surface is concave.

[0062] The second lens L2 has negative refractive power, and its object-side surface is concave and its image-side surface is concave.

[0063] The third lens L3 has positive refractive power, and its object-side surface is convex and its image-side surface is convex.

[0064] The fourth lens L4 has positive refractive power, and its object-side surface is convex and its image-side surface is convex.

[0065] The fifth lens L5 has positive refractive power, and its image-side surface is convex.

[0066] The sixth lens L6 has negative refractive power, its object-side surface is concave, and its image-side surface is convex.

[0067] The seventh lens L7 has positive refractive power, and its object-side surface is convex and its image-side surface is convex.

[0068] Specifically, the focal length is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam, and it characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal length, the stronger the ability to bend light, and the smaller the absolute value of the focal length, the weaker the ability to bend light. When the focal length is a positive number, the refraction of light is convergent; when the focal length is a negative number, the refraction of light is divergent. The focal length can be used to characterize a refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a lens, or can be used to characterize a system formed by multiple lenses (i.e., a lens group).

[0069] In the lens provided in this embodiment, each lens can be fixed to a lens barrel ( Figure 1 (not shown), but is not limited to this.

[0070] Among them, the first lens L1 has negative optical power, which diverges the light at the front end of the optical lens, allowing more light to enter the subsequent lens at a larger angle, which is beneficial to expanding the field of view of the optical lens, thereby capturing a wider scene, and can be suitable for panoramic photography.

[0071] The second lens L2 has negative optical power, which can share the negative optical power of the front end of the optical lens, thereby helping to avoid excessive light deflection caused by excessive concentration of the optical power of the first lens L1, and reducing the difficulty of chromatic aberration correction of the optical lens.

[0072] The third lens L3 has positive refractive power, which is beneficial to the smooth transition of light, facilitates the correction of astigmatism and field curvature, and improves the imaging quality of the optical lens.

[0073] The fourth lens L4 has positive refractive power, which can reasonably distribute the refractive power of the entire optical lens, is conducive to realizing temperature characteristics, and ensures that the lens can still maintain good imaging quality under high and low temperature conditions.

[0074] The fifth lens L5 has positive refractive power, which is conducive to the smooth transition of light, facilitates the correction of astigmatism and field curvature, and improves the imaging quality of the optical lens.

[0075] The sixth lens L6 has negative optical power, which is beneficial to increasing the imaging area of ​​the optical lens, while balancing various aberrations generated by the fifth lens L5, thereby improving the imaging quality of the optical lens.

[0076] The seventh lens L7 has positive refractive power, which helps to collect light, ensure the amount of light transmitted, and improve the relative illumination, so that the brightness of the optical lens at the image plane is improved.

[0077] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 adopt a negative-negative-positive-positive-positive-positive-negative-positive optical power combination, which can reasonably distribute the optical power of each lens so that the light can propagate smoothly in the optical lens and avoid excessive bending of the light on a certain lens surface, which is beneficial to improving the imaging quality and can match imaging chips with more than 8 million pixels.

[0078] At the same time, the surface shape of the lens affects the direction of light propagation and determines how the light bends when passing through the lens, which in turn affects the maximum aperture and light throughput of the lens, as well as the quality and characteristics of the imaging.

[0079] In this embodiment, the surface shapes of the lenses are further reasonably matched, which is conducive to further reducing the total optical length of the entire lens and realizing a miniaturized lens design while satisfying the optical power requirements of each lens and achieving the required optical performance indicators (such as miniaturization, high pixels and high definition, large aperture, high relative illumination, large field of view and weak ghost images, etc.). In addition, the path of light passing through the entire lens can be made smoother, unnecessary reflections and absorption can be reduced, and imaging quality can be improved.

[0080] The optical lens provided in the embodiment of the present invention adopts seven lenses. By reasonably allocating the optical power and surface shape of each lens, the total optical length of the lens is within 30 mm (can be below 27.5 mm), and the aperture number is below 1.65. It can meet the imaging needs of darker environments, and the imaging is clear. It can match imaging chips with more than 8 million pixels and can ensure stable high and low temperature resolution, thereby realizing an optical lens that can take into account miniaturization, high pixels and high definition, large aperture, high relative illumination, large field of view and weak ghost images.

[0081] As a feasible implementation manner, the focal length of the optical lens is F, the focal length of the first lens L1 is f1, the focal length of the second lens L2 is f2, the focal length of the third lens L3 is f3, the focal length of the fourth lens L4 is f4, the focal length of the fifth lens L5 is f5, the focal length of the sixth lens L6 is f6, and the focal length of the seventh lens L7 is f7; -2 <f1 / F<0;-3<f2 / F<0;0<f3 / F<2;0<f4 / F<3;0<f5 / F<2;-2<f6 / F<0;0<f7 / F<3.5。

[0082] Among them, the first lens L1 has an appropriate negative focal length, which is beneficial to expanding the field of view of the optical lens.

[0083] The second lens L2 has an appropriate negative focal length, which can share the negative optical power of the front end of the optical lens, thereby helping to avoid excessive light deflection caused by excessive concentration of the optical power of the first lens L1, and reducing the difficulty of chromatic aberration correction of the optical lens.

[0084] At the same time, reasonable focal length distribution can help reduce dependence on the accuracy of a single lens and alleviate error accumulation during the assembly process, thereby reducing the negative impact of assembly tolerances and improving production yield.

[0085] The third lens L3 has an appropriate positive focal length, which is beneficial to the smooth transition of light, facilitates the correction of astigmatism and field curvature, and improves the imaging quality of the optical lens.

[0086] Further controlling the focal length of the fourth lens L4 can reasonably distribute the optical power of the entire optical lens, which is conducive to realizing temperature characteristics and ensuring that the lens can still maintain good imaging quality under high and low temperature conditions.

[0087] The fifth lens L5 has an appropriate positive focal length, which is beneficial to the smooth transition of light, facilitates the correction of astigmatism and field curvature, and improves the imaging quality of the optical lens.

[0088] The sixth lens L6 has an appropriate negative focal length, which is beneficial to increasing the imaging area of ​​the optical lens, while balancing various aberrations generated by the fifth lens L5, thereby improving the imaging quality of the optical lens.

[0089] The seventh lens L7, as the last lens, adopts a short focal length, which helps to collect light, ensure the amount of light transmitted, and improve the relative illumination, so that the brightness of the optical lens at the image plane is improved.

[0090] As a feasible implementation manner, the focal length of the optical lens is F, the total optical length of the optical lens is TTL, and TTL / F<5.5.

[0091] The total length TTL of the optical lens refers to the distance from the center of the optical axis of the object side of the first lens L1 to the image plane.

[0092] In this embodiment, by controlling the ratio between the total optical length TTL of the optical lens and the focal length F of the optical lens, it is possible to ensure that the overall length of the optical lens is shortened as much as possible while maintaining a certain focal length, thereby making the lens more compact and lightweight and achieving a miniaturized design.

[0093] As a feasible implementation method, Figure 1-Figure 3 As shown, the fifth lens L5 and the sixth lens L6 form a cemented lens group G.

[0094] Among them, Figure 1-Figure 3 As shown, gluing the fifth lens L5 and the sixth lens L6 together can effectively correct the chromatic aberration of the optical lens, reduce the decentering sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; at the same time, it can also reduce the assembly sensitivity of the optical lens, thereby reducing the difficulty of the processing technology of the optical lens and improving the assembly yield of the optical lens.

[0095] As a feasible implementation manner, the focal length of the cemented lens group G is f56, the focal length of the optical lens is F, and 10≤|f56 / F|≤15.

[0096] Among them, by controlling the absolute value of the ratio of the focal length f56 of the cemented lens group G to the focal length F of the optical lens within the range of 10 to 15, the light trend between the fourth lens L4 and the fifth lens L5 can be controlled, the aberration caused by the light incident at a large angle can be reduced, and the light can be more smoothly transitioned to the subsequent lenses, thereby improving the imaging quality.

[0097] At the same time, controlling the f56 / F range also helps to make the lens structure compact, shortening the overall length of the lens, facilitating miniaturization and reducing sensitivity.

[0098] As a feasible implementation method, Figure 1-Figure 3 As shown, the optical lens further includes a stop STO, which is located in the optical path between the third lens L3 and the fourth lens L4.

[0099] Among them, an aperture STO for limiting the light beam is arranged between the third lens L3 and the fourth lens L4. The aperture STO can be arranged near the object side of the fourth lens L4. This can reduce the generation of astigmatism of the optical lens, and is conducive to focusing the light entering the optical system and reducing the rear port diameter of the optical lens.

[0100] As a feasible implementation method, the total optical length of the optical lens is TTL, the image height corresponding to the maximum field angle of the optical lens is H, and 6<TTL / H<7.

[0101] Among them, by limiting the ratio between the total optical length TTL of the optical lens and the image height H corresponding to the maximum field of view angle of the optical lens, the total length of the lens can be better compressed while achieving a large image surface, so that the lens can achieve the design goal of miniaturization, making it easier to mount the optical lens on other imaging devices.

[0102] As a feasible implementation method, the optical back focus of the optical lens is BFL, the total optical length of the optical lens is TTL, and BFL / TTL>1.0.

[0103] The optical back focus BFL of the optical lens refers to the distance from the center of the optical axis of the image side surface of the seventh lens L7 to the image plane.

[0104] In this embodiment, by reasonably limiting the ratio of the optical back focus BFL and the total optical length TTL of the lens, the back focus is longer while achieving miniaturization, which can ensure that structures such as imaging chips and flat filters have sufficient installation space, thereby ensuring that the lens will not interfere with the base and the housing during installation, which is beneficial to the assembly of the module.

[0105] As a feasible implementation method, the entrance pupil diameter of the optical lens is ENPD, the total optical length of the optical lens is TTL, and ENPD / TTL≥0.1.

[0106] Among them, by limiting the ratio between the entrance pupil diameter ENPD of the optical lens and the total optical length TTL of the optical lens, it can be ensured that the lens has a larger entrance pupil diameter, thereby achieving a small aperture number (FNO), which is conducive to achieving a large aperture characteristic, providing more incident light for the optical lens, and is conducive to improving the imaging quality under low light conditions.

[0107] As a feasible implementation manner, the refractive index of the first lens L1 is Nd1, and Nd1≥1.7.

[0108] The first lens L1 is made of a high refractive index material, which is beneficial for reducing the front port diameter and improving the imaging quality.

[0109] As a feasible implementation manner, the focal length of the fifth lens L5 is f5, the focal length of the sixth lens L6 is f6, and 0.5<|f5 / f6|<1.5.

[0110] Among them, by arranging the fifth lens L5 (positive optical power) and the sixth lens L6 (negative optical power) to be glued together and having a reasonable focal length ratio, the effect of eliminating chromatic aberration can be achieved.

[0111] As a feasible implementation manner, the focal length of the second lens L2 is f2, the focal length of the seventh lens L7 is f7, and -1<f2 / f7<-0.7.

[0112] Among them, by reasonably configuring the focal length ratio of the second lens L2 and the seventh lens L7, the aberrations formed by the second lens L2 and the seventh lens L7 can offset each other, thereby effectively improving the resolution of the lens.

[0113] As a feasible implementation manner, the Abbe number of the fifth lens L5 is Vd5, and the refractive index is Nd5; the Abbe number of the sixth lens L6 is Vd6, and the refractive index is Nd6; 3<Vd5 / Vd6<3.5; 0.8<Nd5 / Nd6<0.9.

[0114] In particular, increasing the difference in Abbe number and refractive index between the fifth lens L5 and the sixth lens L6 is more conducive to eliminating chromatic aberration.

[0115] As a feasible implementation, the central curvature radius of the object side surface of the first lens L1 is R1, the central curvature radius of the image side surface of the first lens L1 is R2, the central thickness of the first lens L1 is d1, and 0.8≤R1 / (R2+d1)≤1.5.

[0116] Among them, by setting the first lens L1 in a special lens shape (the shape of the first lens L1 is close to a concentric circle), an optical path difference exists between the peripheral light and the central light, which helps to diverge the central light so that it enters the rear optical system more evenly, and reduces the front port diameter of the lens and the volume, which is conducive to miniaturization and cost reduction.

[0117] As a feasible implementation manner, the central curvature radius of the object side surface of the second lens L2 is R3, the central curvature radius of the image surface of the seventh lens L7 is R13, and the focal length of the optical lens is F, -5.5<R3 / F<-4.5; 6<R13 / F<7.

[0118] Among them, by controlling the curvature radii of the second lens L2 and the seventh lens L7, the relative positions of the pupil images of the secondary reflected ghost images on the object side surfaces of the second lens L2 and the seventh lens L7 on the focal plane can be changed, so that the pupil images of the ghost images are away from the focal plane, effectively reducing the relative energy value of the ghost images and meeting the demand for weak ghost images.

[0119] As a feasible implementation, the central curvature radius of the object-side surface of the first lens L1 is R1, the focal length of the optical lens is F, and 0.5<R1 / F<1.5.

[0120] Among them, by controlling the lower limit of R1 / F, it is helpful to increase the field of view of the optical lens, thereby meeting the needs of wide-range shooting; at the same time, by controlling the upper limit of R1 / F, it is helpful to reduce the effective aperture of the lens and realize miniaturization design.

[0121] As a feasible implementation manner, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all glass lenses.

[0122] Among them, compared with plastic lenses, the refractive index of glass lenses changes less with temperature. Setting each lens to be a glass lens helps to maintain the stability of the focal length of each lens at different temperatures, thereby making the lens insensitive to high and low temperatures, and can well balance the impact of high and low temperatures on the entire lens. No obvious aberrations or other optical problems will occur due to temperature changes, allowing the optical lens to produce clear images within the temperature range of -40℃ to +85℃, which is particularly suitable for camera fields such as sports cameras and car cameras that have harsh environments.

[0123] As a feasible implementation manner, the first lens L1 is an aspherical lens, and the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all spherical lenses.

[0124] Among them, the first lens L1 adopts an aspherical lens, which is beneficial to reducing the effective aperture of the front end of the optical lens, making the entire lens more compact and lightweight.

[0125] Meanwhile, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are spherical lenses, which helps to reduce costs and facilitates manufacturing.

[0126] As a feasible implementation method, Figure 1-Figure 3 As shown, the optical lens provided by the embodiment of the present invention also includes a flat filter CG, which is located on the image side of the seventh lens L7. The flat filter CG can protect the imaging chip from dust and pollution, thereby ensuring the imaging effect of the lens.

[0127] In some cases, the flat filter CG may also be used to correct specific aberrations or filter out unnecessary light, which is not specifically limited in the embodiment of the present invention.

[0128] Specific embodiments of the optical lens applicable to the above-mentioned embodiments are further described below with reference to the accompanying drawings.

[0129] Embodiment 1

[0130] Continue to refer Figure 1 The optical lens provided in the first embodiment of the present invention includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a seventh lens L7 which are arranged in sequence from the object plane to the image plane along the optical axis.

[0131] The fifth lens L5 and the sixth lens L6 form a cemented lens group G; the aperture STO is located in the optical path between the third lens L3 and the fourth lens L4; and the flat filter CG is located on the image side of the seventh lens L7.

[0132] Table 1 describes in detail the surface type, curvature radius, thickness, refractive index and Abbe number of each lens in the optical lens provided in Example 1 in a feasible implementation manner. The optical lens in Table 1 corresponds to Figure 1 Optical lens shown.

[0133] Table 1 Design values ​​of optical physical parameters of optical lenses

[0134]

[0135]

[0136] Among them, the surface numbers in Table 1 are numbered according to the surface order of each lens, where "1" represents the object side of the first lens, "2" represents the image side of the first lens, and so on; the radius of curvature represents the curvature of the lens surface, and the unit is millimeter (mm). A positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, where "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, and the unit is millimeter (mm); the material (nd) represents the refractive index, which refers to the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air, and the refractive index is 1; the material (vd) represents the Abbe number, which refers to the dispersion characteristics of the material between the current surface and the next surface to light, and a blank space represents that the current position is air.

[0137] In this embodiment, the first lens is an aspherical lens, and both the object side surface 1 and the image side surface 2 thereof are aspherical surfaces.

[0138] Its aspherical surface shape equation Z can satisfy:

[0139]

[0140] Wherein, Z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of y along the optical axis; c = 1 / R, R represents the paraxial curvature radius of the mirror surface; K is the cone coefficient; A, B, C, D, and E are high-order aspheric coefficients.

[0141] Exemplarily, Table 2 describes in detail the cone coefficient K and the higher-order coefficients A, B, C, D, and E of the aspheric lens surface 1 and surface 2 in the first embodiment in a feasible implementation manner.

[0142] Table 2 Design values ​​of aspheric cone coefficients of aspheric lenses in optical lenses

[0143] Serial number K A B C D E 1 -1.06 -8.2E-04 -8.5E-05 2.9E-06 -3.2E-08 4.4E-11 2 -0.64 -2.0E-03 -5.7E-04 6.2E-05 -5.6E-06 2.0E-07

[0144] The total optical length of the optical lens provided in the first embodiment is 27.17372 mm.

[0145] Figure 4 The light fan diagram of the optical lens provided in the first embodiment of the present invention can not only reflect the monochromatic aberrations of different wavelengths, but also indicate the magnitude of the vertical axis chromatic aberration. The figure shows the light fan diagram of the optical lens at infinite object distance. The horizontal axis in a single figure is the normalized beam aperture, and the vertical axis is the vertical axis aberration. The vertical axis in a single image can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. Ideally, each curve should completely coincide with the horizontal axis, and at this time all light rays in the field of view are focused on the same point on the image plane. By Figure 4It can be seen that the vertical axis aberration of each wavelength of the optical lens is well corrected. In addition, the curves of each color do not have obvious dispersion, which shows that the optical lens also has good correction for chromatic aberration and can meet the use requirements of the optical lens.

[0146] Figure 5 This is an axial aberration curve diagram of the optical lens provided in Example 1 of the present invention, wherein the axial aberration curve of the lens can better show the state of parameters such as spherical aberration of the optical system under different wavelength conditions. The vertical direction in the figure represents the normalization of the aperture, 0 represents the optical axis, and the vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Figure 5 It can be seen that the axial aberrations of normalized apertures at different wavelengths are all within a reasonable range, and a clear image can be achieved.

[0147] Figure 6 This is a field curvature distortion diagram of the optical lens provided in Example 1 of the present invention. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, without units, where T represents the meridian and S represents the arc loss. In the right coordinate system of the figure, the horizontal coordinate represents the magnitude of the distortion (F-Tan(Theta)), in units of %; the vertical coordinate represents the normalized image height, without units. Figure 6 It can be seen that the field curvature of the optical lens provided in this embodiment is effectively controlled, and at the same time, the distortion is also well corrected.

[0148] Embodiment 2

[0149] Continue to refer Figure 2 The optical lens provided in the second embodiment of the present invention includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a seventh lens L7 which are arranged in sequence from the object plane to the image plane along the optical axis.

[0150] The fifth lens L5 and the sixth lens L6 form a cemented lens group G; the aperture STO is located in the optical path between the third lens L3 and the fourth lens L4; and the flat filter CG is located on the image side of the seventh lens L7.

[0151] Table 3 describes in detail the surface type, curvature radius, thickness, refractive index and Abbe number of each lens in the optical lens provided in Example 2 in a feasible implementation manner. The optical lens in Table 3 corresponds to Figure 2 Optical lens shown.

[0152] Table 3 Design values ​​of optical physical parameters of optical lenses

[0153] Surface number Surface type Radius of curvature thickness Materials (n.d.) Material (vd) 1 Aspheric 5.00 1.95 1.806 40.91 2 Aspheric 2.48 2.70 3 Spherical -25.00 0.70 1.487 70.44 4 Spherical 8.30 1.90 5 Spherical 24.31 2.20 1.871 40.73 6 Spherical -11.75 3.01 STO(Aperture) PL Infinity 0.25 8 Spherical 50.00 1.90 1.593 68.34 9 Spherical -8.75 0.10 10 Spherical 40.00 2.80 1.497 81.61 11 Spherical -5.26 0.60 1.847 23.78 12 Spherical -21.91 0.10 13 Spherical 34.00 2.20 1.743 49.22 14 Spherical -15.94 2.00 15 Spherical Infinity 0.30 1.517 64.20 16 Spherical Infinity 3.89 17 Spherical Infinity 0.50 1.517 64.20 18 Spherical Infinity 0.05 IMA Infinity /

[0154] Among them, the surface numbers in Table 3 are numbered according to the surface order of each lens, where "1" represents the object side of the first lens, "2" represents the image side of the first lens, and so on; the radius of curvature represents the curvature of the lens surface, and the unit is millimeter (mm). A positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, where "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, and the unit is millimeter (mm); the material (nd) represents the refractive index, which refers to the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air, and the refractive index is 1; the material (vd) represents the Abbe number, which refers to the dispersion characteristics of the material between the current surface and the next surface to light, and a blank space represents that the current position is air.

[0155] In this embodiment, the first lens is an aspherical lens, and both the object side surface 1 and the image side surface 2 thereof are aspherical surfaces.

[0156] Its aspherical surface shape equation Z can satisfy:

[0157]

[0158] Wherein, Z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of y along the optical axis; c = 1 / R, R represents the paraxial curvature radius of the mirror surface; K is the cone coefficient; A, B, C, D, and E are high-order aspheric coefficients.

[0159] Exemplarily, Table 4 describes in detail the cone coefficient K and the higher-order coefficients A, B, C, D, and E of the aspheric lens surface 1 and surface 2 in the second embodiment in a feasible implementation manner.

[0160] Table 4 Design values ​​of aspheric cone coefficients of aspheric lenses in optical lenses

[0161] Serial number K A B C D E 1 -1.06 -9.1E-04 -9.7E-05 3.7E-06 -5.4E-08 2.8E-10 2 -0.65 -2.0E-03 -7.0E-04 9.3E-05 -1.0E-05 6.3E-07

[0162] The total optical length of the optical lens provided in the second embodiment is 27.14996 mm.

[0163] Figure 7 The light fan diagram of the optical lens provided in the second embodiment of the present invention can not only reflect the monochromatic aberrations of different wavelengths, but also indicate the magnitude of the vertical axis chromatic aberration. The figure shows the light fan diagram of the optical lens at infinite object distance. The horizontal axis in a single figure is the normalized beam aperture, and the vertical axis is the vertical axis aberration. The vertical axis in a single image can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. Ideally, each curve should completely coincide with the horizontal axis, and at this time all light rays in the field of view are focused on the same point on the image plane. By Figure 7It can be seen that the vertical axis aberration of each wavelength of the optical lens is well corrected. In addition, the curves of each color do not have obvious dispersion, which shows that the optical lens also has good correction for chromatic aberration and can meet the use requirements of the optical lens.

[0164] Figure 8 This is an axial aberration curve diagram of the optical lens provided in Example 2 of the present invention, wherein the axial aberration curve of the lens can better show the state of parameters such as spherical aberration of the optical system under different wavelength conditions. The vertical direction in the figure represents the normalization of the aperture, 0 represents the optical axis, and the vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Figure 8 It can be seen that the axial aberrations of normalized apertures at different wavelengths are all within a reasonable range, and a clear image can be achieved.

[0165] Fig. 9 This is a field curvature distortion diagram of the optical lens provided in Example 2 of the present invention. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, without units, where T represents the meridian and S represents the arc loss. In the right coordinate system of the figure, the horizontal coordinate represents the magnitude of the distortion (F-Tan(Theta)), in units of %; the vertical coordinate represents the normalized image height, without units. Fig. 9 It can be seen that the field curvature of the optical lens provided in this embodiment is effectively controlled, and at the same time, the distortion is also well corrected.

[0166] Embodiment 3

[0167] Continue to refer Figure 3 The optical lens provided in the third embodiment of the present invention includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a seventh lens L7 which are arranged in sequence from the object plane to the image plane along the optical axis.

[0168] The fifth lens L5 and the sixth lens L6 form a cemented lens group G; the aperture STO is located in the optical path between the third lens L3 and the fourth lens L4; and the flat filter CG is located on the image side of the seventh lens L7.

[0169] Table 5 describes in detail the surface type, curvature radius, thickness, refractive index and Abbe number of each lens in the optical lens provided in Example 3 in a feasible implementation manner. The optical lens in Table 5 corresponds to Figure 3 Optical lens shown.

[0170] Table 5 Design values ​​of optical physical parameters of optical lenses

[0171]

[0172]

[0173] Among them, the surface numbers in Table 5 are numbered according to the surface order of each lens, where "1" represents the object side of the first lens, "2" represents the image side of the first lens, and so on; the radius of curvature represents the curvature of the lens surface, and the unit is millimeter (mm). A positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, where "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, and the unit is millimeter (mm); the material (nd) represents the refractive index, which refers to the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air, and the refractive index is 1; the material (vd) represents the Abbe number, which refers to the dispersion characteristics of the material between the current surface and the next surface to light, and a blank space represents that the current position is air.

[0174] In this embodiment, the first lens is an aspherical lens, and both the object side surface 1 and the image side surface 2 thereof are aspherical surfaces.

[0175] Its aspherical surface shape equation Z can satisfy:

[0176]

[0177] Wherein, Z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of y along the optical axis; c = 1 / R, R represents the paraxial curvature radius of the mirror surface; K is the cone coefficient; A, B, C, D, and E are high-order aspheric coefficients.

[0178] Exemplarily, Table 6 describes in detail the cone coefficient K and the higher-order coefficients A, B, C, D, and E of the aspheric lens surface 1 and surface 2 in this embodiment 3 in a feasible implementation manner.

[0179] Table 6 Design values ​​of aspheric cone coefficients of aspheric lenses in optical lenses

[0180] Serial number K A B C D E 1 -1.01 -8.4E-04 -6.2E-05 1.8E-06 -9.1E-09 -1.3E-10 2 -0.58 -2.6E-03 -4.5E-04 3.1E-05 -9.0E-07 -4.0E-07

[0181] The total optical length of the optical lens provided in the third embodiment is 27.30174 mm.

[0182] Fig.10The light fan diagram of the optical lens provided in the third embodiment of the present invention can not only reflect the monochromatic aberrations of different wavelengths, but also indicate the magnitude of the vertical axis chromatic aberration. The figure shows the light fan diagram of the optical lens at infinite object distance. The horizontal axis in a single figure is the normalized beam aperture, and the vertical axis is the vertical axis aberration. The vertical axis in a single image can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. Ideally, each curve should completely coincide with the horizontal axis, and at this time all light rays in the field of view are focused on the same point on the image plane. By Fig.10 It can be seen that the vertical axis aberration of each wavelength of the optical lens is well corrected. In addition, the curves of each color do not have obvious dispersion, which shows that the optical lens also has good correction for chromatic aberration and can meet the use requirements of the optical lens.

[0183] Fig.11 This is an axial aberration curve diagram of the optical lens provided in Example 3 of the present invention, wherein the axial aberration curve of the lens can better show the state of parameters such as spherical aberration of the optical system under different wavelength conditions. The vertical direction in the figure represents the normalization of the aperture, 0 represents the optical axis, and the vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Fig.11 It can be seen that the axial aberrations of normalized apertures at different wavelengths are all within a reasonable range, and a clear image can be achieved.

[0184] Fig.12 This is a field curvature distortion diagram of the optical lens provided in Example 3 of the present invention. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, without units, where T represents the meridian and S represents the arc loss. In the right coordinate system of the figure, the horizontal coordinate represents the magnitude of the distortion (F-Tan(Theta)), in units of %; the vertical coordinate represents the normalized image height, without units. Fig.12 It can be seen that the field curvature of the optical lens provided in this embodiment is effectively controlled, and at the same time, the distortion is also well corrected.

[0185] In order to more clearly illustrate the above embodiments, Table 7 details the specific optical physical parameters of each lens in the optical lens provided in Embodiments 1 to 3 of the present invention.

[0186] Table 7 Design values ​​of optical physical parameters of optical lenses

[0187] Embodiment 1 Embodiment 2 Embodiment 3 TTL / H 6.740 6.734 6.771 TTL / F 5.345 5.334 5.369 BFL / TTL 1.341 1.324 1.184 ENPD / TTL 0.113 0.115 0.114 f1 / F -1.809 -1.827 -1.696 f2 / F -2.534 -2.486 -2.488 f3 / F 1.802 1.829 1.650 f4 / F 2.583 2.490 2.493 f5 / F 1.839 1.870 1.724 f6 / F -1.493 -1.550 -1.382 |f5 / f6| 1.232 1.206 1.247 f7 / F 2.815 2.909 2.914 f2 / f7 -0.900 -0.854 -0.854 |f56 / F| 12.688 13.099 11.954 Vd5 / Vd6 3.431 3.431 3.431 Nd5 / Nd6 0.811 0.811 0.811 R1 / (R2+d1) 1.130 1.128 1.145 R3 / F -4.918 -4.911 -4.917 R13 / F 6.491 6.680 6.588 R1 / F 0.997 0.982 1.082

[0188] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. 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 which are arranged in sequence from the object plane to the image plane along the optical axis; The first lens has negative optical power, and its object side surface is convex, and its image side surface is concave; The second lens has negative optical power, and its object side surface is concave, and its image side surface is concave; The third lens has positive refractive power, and its object side surface is convex, and its image side surface is convex; The fourth lens has positive refractive power, and its object side surface is convex, and its image side surface is convex; The fifth lens has positive refractive power, and its image side surface is convex, and its image side surface is convex; The sixth lens has negative optical power, its object side surface is concave, and its image side surface is convex; The seventh lens has positive refractive power, and its object side surface is convex, and its image side surface is convex.

2. The optical lens according to claim 1, characterized in that: The focal length of the optical lens is F, 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, and the focal length of the seventh lens is f7; -2 <f1 / F<0;-3<f2 / F<0;0<f3 / F<2;0<f4 / F<3; 0 <f5 / F<2;-2<f6 / F<0;0<f7 / F<3.5。 3. The optical lens according to claim 1, characterized in that: The focal length of the optical lens is F, and the total optical length of the optical lens is TTL; TTL / F<5.

5.

4. The optical lens according to claim 1, characterized in that: The fifth lens and the sixth lens form a cemented lens group.

5. The optical lens according to claim 4, characterized in that: The focal length of the cemented lens group is f56, and the focal length of the optical lens is F; 10≤|f56 / F|≤15.

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

7. The optical lens according to claim 1, characterized in that: The total optical length of the optical lens is TTL, and the image height corresponding to the maximum field angle of the optical lens is H; 6<TTL / H<7.

8. The optical lens according to claim 1, characterized in that: The optical back focus of the optical lens is BFL, and the total optical length of the optical lens is TTL; BFL / TTL>1.

0.

9. The optical lens according to claim 1, characterized in that: The entrance pupil diameter of the optical lens is ENPD, and the total optical length of the optical lens is TTL; ENPD / TTL≥0.

1.

10. The optical lens according to claim 1, characterized in that: The refractive index of the first lens is Nd1, where Nd1≥1.

7.

11. The optical lens according to claim 1, characterized in that: The focal length of the fifth lens is f5, and the focal length of the sixth lens is f6; 0.5<|f5 / f6|<1.

5.

12. The optical lens according to claim 1, characterized in that: The focal length of the second lens is f2, and the focal length of the seventh lens is f7; -1<f2 / f7<-0.

7.

13. The optical lens according to claim 1, characterized in that: The Abbe number of the fifth lens is Vd5, and the refractive index is Nd5; The Abbe number of the sixth lens is Vd6, and the refractive index is Nd6; 3<Vd5 / Vd6<3.5; 0.8<Nd5 / Nd6<0.

9.

14. The optical lens according to claim 1, characterized in that: The central curvature radius of the object side surface of the first lens is R1, the central curvature radius of the image side surface of the first lens is R2, and the central thickness of the first lens is d1; 0.8≤R1 / (R2+d1)≤1.

5.

15. The optical lens according to claim 1, characterized in that: The central curvature radius of the object side surface of the second lens is R3, the central curvature radius of the image surface of the seventh lens is R13, and the focal length of the optical lens is F; -5.5<R3 / F<-4.5; 6<R13 / F<7.

16. The optical lens according to claim 1, characterized in that: The central curvature radius of the object side of the first lens is R1, and the focal length of the optical lens is F; 0.5<R1 / F<1.5.

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