An optical lens

Abstract

The utility model discloses an optical lens, including first lens, second lens, third lens, fourth lens, fifth lens and sixth lens that arrange in proper order from object plane to image plane along the optical axis, the optical power of first lens, second lens and fifth lens is negative, the optical power of third lens, fourth lens and sixth lens is positive, the field angle of optical lens is FOV, and the half of image height corresponding to the maximum field of view is ImgH, and the total length of light is TTL, wherein, 21 degree less than or equal to FOV x ImgH / TTL less than or equal to 23 degree. Through the reasonable setting lens number in optical lens, the optimization each lens's optical power and its relative position, have realized the balanced design of compact structure, big field angle and big target surface size while satisfying the imaging quality requirement.

Description

Technical Field

[0001] This utility model relates to the field of optical device technology, and in particular to an optical lens. Background Technology

[0002] As an important in-vehicle safety monitoring device, dashcams must be able to continuously and stably capture clear and accurate images in complex driving environments. This requires its core imaging component—the optical lens—to not only have a large aperture to ensure sufficient light transmission in low-light and nighttime conditions, but also a wide dynamic range to cope with drastic changes in lighting. Simultaneously, the lens structure must be compact and cost-effective to suit in-vehicle applications. Currently, dashcam optical lenses on the market employ complex structures in pursuit of large apertures, resulting in problems such as long overall lens length, high cost, and unstable performance. Utility Model Content

[0003] This invention provides an optical lens that achieves a compact structure and a balanced design of a large field of view and a large target surface size.

[0004] This utility model embodiment provides an optical lens, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical axis from the object plane to the image plane;

[0005] The first lens, the second lens, and the fifth lens have negative optical power, while the third lens, the fourth lens, and the sixth lens have positive optical power.

[0006] The field of view of the optical lens is FOV, half of the image height corresponding to the maximum field of view is ImgH, and the total optical length is TTL;

[0007] Wherein, 21°≤FOV×ImgH / TTL≤23°.

[0008] Optionally, the field of view of the optical lens is FOV, and the effective optical focal length is f;

[0009] Among them, 45° / mm < FOV / f < 55° / mm.

[0010] Optionally, the effective focal length of the optical lens is f, and half of the image height corresponding to the maximum field of view is ImgH;

[0011] Among them, 0.8 < f / ImgH < 0.9.

[0012] Optionally, the optical power of the first lens is Φ1, the optical power of the second lens is Φ2, the optical power of the third lens is Φ3, the combined optical power of the fourth and fifth lenses is Φ45, the optical power of the sixth lens is Φ6, and the optical power of the optical lens is Φ.

[0013] Among them, -0.59<Φ1 / Φ<-0.39, -0.59<Φ2 / Φ<-0.39, 0.34<Φ3 / Φ<0.58, -0.03<Φ45 / Φ<0.0075, 0<Φ6 / Φ<0.55.

[0014] Optionally, the refractive index of the third lens is Nd3, where 1.7 <Nd3<2.05;

[0015] The fourth lens and the fifth lens are cemented together. The Abbe number of the fourth lens is Vd4, and the Abbe number of the fifth lens is Vd5, wherein 55 < Vd4 < 61.7, 19.3 < Vd5 < 21.3.

[0016] The Abbe number of the sixth lens is Vd6, where 55 < Vd6 < 59.7.

[0017] Optionally, the total optical length of the optical lens is TTL, and the effective optical focal length is f;

[0018] Where 7≤TTL / f≤8.

[0019] Optionally, the optical lens has a BFL back focal length and a TTL total optical length.

[0020] Among them, BFL / TTL > 0.18.

[0021] Optionally, the first lens includes a first object-side surface near the object surface and a first image-side surface near the image surface, wherein the first object-side surface is convex and the first image-side surface is concave.

[0022] The second lens includes a second object-side surface near the object plane and a second image-side surface near the image plane. The second object-side surface is concave, and the second image-side surface is either convex or concave.

[0023] The third lens includes a third object-side surface near the object plane and a third image-side surface near the image plane. The third object-side surface is convex, and the third image-side surface is convex.

[0024] The fourth lens includes a fourth object-side surface near the object plane and a fourth image-side surface near the image plane. The fourth object-side surface is convex, and the fourth image-side surface is convex.

[0025] The fifth lens includes a fifth object-side surface near the object plane and a fifth image-side surface near the image plane. The fifth object-side surface is concave, and the fifth image-side surface is concave.

[0026] The sixth lens includes a sixth object-side surface near the object plane and a sixth image-side surface near the image plane. The sixth object-side surface is convex, and the sixth image-side surface is convex.

[0027] Optionally, the first lens and the third lens are glass spherical lenses, and the second lens, the fourth lens, the fifth lens and the sixth lens are plastic aspherical lenses.

[0028] Optionally, the optical lens may further include an aperture stop and a filter;

[0029] The aperture stop is disposed in the optical path between the third lens and the fourth lens;

[0030] The filter is disposed in the optical path between the sixth lens and the image plane.

[0031] The optical lens provided by this utility model comprises six lenses with optical power. By rationally setting the number of lenses, the total length of the optical lens can be ensured to be appropriate, achieving a relatively miniaturized design while maintaining small imaging aberrations and high image quality. Furthermore, the optical power of the six lenses is arranged in a negative-negative-positive-positive-negative-positive pattern. This rational arrangement of the optical power of the six lenses increases the aperture of the optical lens and improves its imaging resolution. The field of view (FOV), half the image height corresponding to the maximum field of view (ImgH), and the total optical length (TTL) satisfy the condition 21°≤FOV×ImgH / TTL≤23°. This allows for a large field of view and a large target surface, while effectively suppressing distortion, reducing the risk of distortion, and ensuring the imaging effect of the optical lens.

[0032] It should be understood that the description in this section is not intended to identify key or essential features of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily apparent from the following description. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of the optical lens provided in Embodiment 1 of this utility model;

[0035] Figure 2 A schematic diagram of the spherical aberration curve of the optical lens provided in Embodiment 1 of this utility model;

[0036] Figure 3 This is a schematic diagram of the structure of the optical lens provided in Embodiment 2 of this utility model;

[0037] Figure 4 A schematic diagram of the spherical aberration curve of the optical lens provided in Embodiment 2 of this utility model;

[0038] Figure 5 This is a schematic diagram of the structure of the optical lens provided in Embodiment 3 of this utility model;

[0039] Figure 6 This is a schematic diagram of the spherical aberration curve of the optical lens provided in Embodiment 3 of this utility model. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0041] Example 1

[0042] Figure 1 This is a schematic diagram of the structure of the optical lens provided in Embodiment 1 of this utility model, as shown below. Figure 1 As shown, the optical lens provided in Embodiment 1 of this utility model includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106 arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the first lens 101, the second lens 102, and the fifth lens 105 is negative, while the optical power of the third lens 103, the fourth lens 104, and the sixth lens 106 is positive; the field of view of the optical lens is FOV, half of the image height corresponding to the maximum field of view is ImgH, and the total optical length is TTL; wherein, 21°≤FOV×ImgH / TTL≤23°.

[0043] Specifically, the optical lens provided in this embodiment includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106. That is, the optical lens includes six lenses with optical power. The arrangement of six lenses ensures that the number of lenses in the optical system is reasonable. Too many lenses will result in a large lens size, and too few lenses will result in large aberrations due to a single lens bearing a large optical power. This ensures that the optical system is miniaturized while ensuring small imaging aberrations and high imaging quality.

[0044] Furthermore, optical power is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam, characterizing the optical system's ability to deflect light. The larger the absolute value of the optical power, the stronger the bending ability of light; the smaller the absolute value, the weaker the bending ability. When the optical power is positive, the refraction of light is converging; when the optical power is negative, the refraction of light is diverging. In this embodiment, the first lens 101 and the second lens 102 are both negative optical power lenses. The first lens 101 and the second lens 102, as the lenses that first adjust the incident light in the optical lens, have a negative optical power setting that ensures a larger aperture before the light enters the aperture stop, increasing the aperture of the optical lens and enabling the lens to still produce clear images under dim or dark conditions. The positive optical power third lens 103 and fourth lens 104 can promptly correct the large aberrations produced by the first lens 101 and the second lens 102, especially significantly correcting the edge aberrations of the optical lens, thereby improving the imaging resolution of the optical system. Furthermore, the optical power of the fifth lens 105 is negative, and the optical power of the sixth lens 106 is positive. The optical power of each subsequent lens in the optical path is different from that of the preceding lens, which is beneficial for aberration correction.

[0045] Furthermore, the field of view (FOV) of the optical lens, half the image height corresponding to the maximum field of view (ImgH), and the total optical length (TTL) satisfy the condition 21° ≤ FOV × ImgH / TTL ≤ 23°. Meeting this condition allows the optical system to achieve a large field of view, a large target surface, and a large aperture, while effectively suppressing distortion, reducing the risk of distortion, and ensuring the imaging effect of the optical lens. Specifically, in this embodiment of the invention, the field of view of the optical lens can reach 143°, and the aperture number (F.NO) satisfies 1.55 < F.NO < 1.6.

[0046] In summary, the optical system provided by this embodiment of the invention, by setting the optical lens to include six lenses with optical power, ensures a suitable total length of the optical lens through a reasonable setting of the number of lenses. This achieves a relatively miniaturized design of the optical lens while ensuring small imaging aberrations and high imaging quality. Furthermore, the optical power of the six lenses is arranged in a negative-negative-positive-positive-negative-positive pattern. This reasonable arrangement of the optical power of the six lenses increases the aperture of the optical lens and improves its imaging resolution. The field of view (FOV), half the image height corresponding to the maximum field of view (ImgH), and the total optical length (TTL) satisfy 21°≤FOV×ImgH / TTL≤23°. This allows for a large field of view and a large target surface, while effectively suppressing distortion, reducing the risk of distortion, and ensuring the imaging effect of the optical lens.

[0047] Based on the above embodiments, continue to refer to Figure 1 As shown, the optical lens also includes an aperture stop STO and a filter 107; the aperture stop STO is disposed in the optical path between the third lens 103 and the fourth lens 104; the filter 107 is disposed in the optical path between the sixth lens 106 and the image plane.

[0048] Specifically, by setting the aperture stop STO, the propagation direction of the light beam can be adjusted, which is beneficial to improving image quality. Furthermore, in this optical lens, the aperture stop STO can be located in the optical path between the third lens 103 and the fourth lens 104. The purpose is to control the higher aberrations of the lens at the front end, ensuring good image quality while improving image height and enlarging the target area at the rear end of the lens. Further, the filter 107 is disposed in the optical path between the sixth lens 106 and the image plane. The filter 107 can filter out interfering light, improving the imaging effect of the optical lens.

[0049] Furthermore, the optical lens provided in this embodiment may also include a protective glass and an imaging sensor. The protective glass can be disposed on the image-side of the filter, and the imaging sensor can be disposed on the image-side of the protective glass. The optical system is protected by the protective glass, and the image is acquired by the imaging sensor, enabling the optical system to perform its normal imaging function.

[0050] Based on the above embodiments, the field of view (FOV) of the optical lens is denoted by f; wherein 45° / mm < FOV / f < 55° / mm. When the optical system meets these conditions, it is beneficial to obtain a larger field of view while reducing tolerance sensitivity.

[0051] Based on the above embodiments, the effective focal length of the optical lens is f, and half of the image height corresponding to the maximum field of view is ImgH; where 0.8 < f / ImgH < 0.9. When the optical system meets this condition, it can achieve high pixel requirements and improve image quality.

[0052] Based on the above embodiments, the optical power of the first lens 101 is Φ1, the optical power of the second lens 102 is Φ2, the optical power of the third lens 103 is Φ3, the combined optical power of the fourth lens 104 and the fifth lens 105 is Φ45, the optical power of the sixth lens 106 is Φ6, and the optical power of the optical lens is Φ; wherein, -0.59<Φ1 / Φ<-0.39, -0.59<Φ2 / Φ<-0.39, 0.34<Φ3 / Φ<0.58, -0.03<Φ45 / Φ<0.0075, 0<Φ6 / Φ<0.55.

[0053] Specifically, setting the optical power of the first lens 101 within this range allows object-side light to be gently collected into the imaging system while reducing the diameter of the front port of the lens, which is beneficial for realizing a miniaturized optical lens design. In addition, by reasonably setting the optical power ranges of other lenses, off-axis aberrations can be corrected, the spherical aberration and chromatic aberration of the optical lens can be corrected, and field curvature can be optimized, so as to improve the image quality of the lens.

[0054] On the basis of the above embodiments, the refractive index of the third lens 103 is Nd3, where 1.7<Nd3<2.05; the third lens 103 adopts a high-refractive-index lens, which can bend light more strongly, thereby increasing the light converging capability, improving the overall brightness and contrast of the image, and at the same time, under the same optical performance requirements, the high-refractive-index lens element is thinner, which helps reduce the overall axial length of the lens.

[0055] The fourth lens 104 and the fifth lens 105 are arranged in a cemented manner, the Abbe number of the fourth lens 104 is Vd4, and the Abbe number of the fifth lens 105 is Vd5, where 55<Vd4<61.7, 19.3<Vd5<21.3.

[0056] Specifically, the cemented joint of the fourth lens 104 and the fifth lens 105 can be understood as the surface of the fourth lens 104 near the image plane being bonded to the surface of the fifth lens 105 near the object plane; that is, the image-side surface of the fourth lens 104 and the object-side surface of the fifth lens 105 are bonded together. By cementing the fourth lens 104 and the fifth lens 105, the air gap between them can be reduced, which helps to reduce the overall optical length of the lens. It also reduces tolerance sensitivity issues such as tilting / eccentricity during lens assembly, simplifies the assembly process in lens manufacturing, and improves equipment efficiency. Simultaneously, the cemented joint of the fourth lens 104 and the fifth lens 105 can reduce light loss caused by inter-lens reflection, increase illumination, and significantly suppress ghosting and flare, especially in high-contrast environments such as backlighting, resulting in cleaner, higher-contrast images. Furthermore, cemented lenses can be used to minimize or eliminate chromatic aberration. Using cemented lenses in optical lenses can improve image quality and reduce light energy reflection loss, thereby improving image quality and enhancing the sharpness of the lens image. Furthermore, the bonding between the fourth lens 104 and the fifth lens 105 can be achieved by using a gasket for support or by adhesive bonding. This embodiment of the invention does not limit the specific bonding method. Furthermore, the Abbe number Vd4 of the fourth lens 104 satisfies 55 < Vd4 < 61.7, and the Abbe number Vd5 of the fifth lens 105 satisfies 19.3 < Vd5 < 21.3. By setting the fourth lens 104 as a high Abbe number lens with positive optical power and the fifth lens 105 as a low Abbe number lens with negative optical power, bonding lenses with different dispersion characteristics together can effectively correct aberrations caused by differences in the refractive index of different colors of light, thereby improving the color reproduction and sharpness of the image.

[0057] Furthermore, the Abbe number of the sixth lens 106 is Vd6, where 55 < Vd6 < 59.7. Setting the sixth lens 106 as a high Abbe number lens can effectively reduce the chromatic aberration of the system, thereby obtaining high-definition image quality and facilitating better matching with the sensor.

[0058] Based on the above embodiments, the total optical length of the optical lens is TTL, and the effective optical focal length is f; where 7 ≤ TTL / f ≤ 8. When the optical system meets this condition, light can be better focused onto the image plane, the optical lens has higher resolution, and it meets the requirements of miniaturization design.

[0059] Based on the above embodiments, the optical lens has a back focal length of BFL and a total optical length of TTL; wherein, BFL / TTL > 0.18. When the optical system meets this condition, it can ensure that the imaging sensor and filter have sufficient installation space, reducing the installation difficulty of the optical lens.

[0060] Based on the above embodiments, the first lens 101 includes a first object-side surface near the object plane and a first image-side surface near the image plane, the first object-side surface being convex and the first image-side surface being concave; the second lens 102 includes a second object-side surface near the object plane and a second image-side surface near the image plane, the second object-side surface being concave and the second image-side surface being either convex or concave; the third lens 103 includes a third object-side surface near the object plane and a third image-side surface near the image plane, the third object-side surface being convex and the third image-side surface being convex; the fourth lens 104 includes a fourth object-side surface near the object plane and a fourth image-side surface near the image plane, the fourth object-side surface being convex and the fourth image-side surface being convex; the fifth lens 105 includes a fifth object-side surface near the object plane and a fifth image-side surface near the image plane, the fifth object-side surface being concave and the fifth image-side surface being concave; the sixth lens 106 includes a sixth object-side surface near the object plane and a sixth image-side surface near the image plane, the sixth object-side surface being convex and the sixth image-side surface being convex.

[0061] Specifically, the object-side surface of a lens can be understood as the surface of the lens closest to the object plane, and the image-side surface can be understood as the surface of the lens closest to the image plane. The first object-side surface is convex, and the first image-side surface is concave. That is, the object-side surface of the first lens 101 convexes towards the object plane near the optical axis, and the image-side surface is concave towards the image plane near the optical axis. In other words, the first lens 101 is a lens with a convex-concave structure. Specifically, the first lens 101 can be a meniscus negative lens that is convex in the front and concave in the back. This surface design can further smooth the object-side light rays into the imaging system while reducing the front aperture of the lens.

[0062] The second object side is concave, and the second image side is convex or concave. That is, the object side of the second lens 102 is concave towards the object surface at the position near the optical axis, and the image side is convex or concave towards the image surface at the position near the optical axis. In other words, the second lens 102 is a lens with a concave-convex structure or a double-concave structure.

[0063] The third object-side surface is convex, and the third image-side surface is convex. That is, the object-side surface of the third lens 103 convexes towards the object surface near the optical axis, and the image-side surface convexes towards the image surface near the optical axis. In other words, the third lens 103 is a lens with a biconvex structure.

[0064] The fourth object-side surface is convex, and the fourth image-side surface is also convex. That is, the object-side surface of the fourth lens 104 convexes towards the object surface near the optical axis, and the image-side surface convexes towards the image surface near the optical axis. In other words, the fourth lens 104 is a lens with a biconvex structure.

[0065] The fifth object-side surface is concave, and the fifth image-side surface is also concave. That is, the object-side surface of the fifth lens 105 is concave towards the object surface near the optical axis, and the image-side surface is concave towards the image surface near the optical axis. In other words, the fifth lens 105 is a double-concave lens.

[0066] The sixth object-side surface is convex, and the sixth image-side surface is also convex. That is, the object-side surface of the sixth lens 106 convexes towards the object plane near the optical axis, and the image-side surface convexes towards the image plane near the optical axis. In other words, the sixth lens 106 is a biconvex lens. This biconvex structure of the sixth lens 106 effectively reduces the system's light emission angle, facilitating better matching with the sensor.

[0067] By designing the surface shape of each lens and combining the optical power of each lens, the imaging effect of the optical lens and the overall size of the optical lens can be further adjusted.

[0068] Based on the above embodiments, the first lens 101 and the third lens 103 are glass spherical lenses, and the second lens 102, the fourth lens 104, the fifth lens 105 and the sixth lens 106 are plastic aspherical lenses.

[0069] Specifically, spherical lenses are characterized by a constant curvature from the center to the periphery, ensuring a simple lens setup. Furthermore, due to the low coefficient of thermal expansion and good stability of glass lenses, both the first lens 101 and the third lens 103 are glass spherical lenses. The thermal properties of glass spherical lenses are more stable, ensuring good resolving power over a wide temperature range when handling higher optical powers. Moreover, the range of glass materials available is wider, and the choice of refractive index and Abbe number is relatively flexible, allowing for better control of higher aberrations and chromatic aberration, meeting the needs of use under complex conditions.

[0070] Aspherical lenses are characterized by a continuous change in curvature from the center to the periphery, unlike spherical lenses which have a constant curvature from the center to the periphery. Aspherical lenses possess superior curvature radius characteristics, offering advantages in improving distortion and astigmatism. The second lens 102, fourth lens 104, fifth lens 105, and sixth lens 106 are all made of plastic aspherical lenses. The use of plastic aspherical lenses helps to simplify the manufacturing process and reduces the cost of the optical system.

[0071] Therefore, the optical lens provided in this embodiment of the present invention can adopt a combination of glass spherical lenses and plastic aspherical lenses, which can effectively control the cost of the fixed-focus lens while ensuring the optical performance of the fixed-focus lens; at the same time, the materials of each lens have a mutual compensating effect, which can ensure normal use in high and low temperature environments.

[0072] Furthermore, in this embodiment of the invention, the aspherical lens of the optical system satisfies the following formula:

[0073]

[0074] Where z is the axial sagitta in the Z-direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, numerically the reciprocal of the radius of curvature; k is the coefficient of the fitted conic section; and AG are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial. Higher-order coefficients not shown in the embodiments are defaulted to 0.

[0075] As a feasible implementation method, the parameters of each lens in the optical lens will be explained next.

[0076] Table 1. Optical design values ​​for the optical lens in Example 1

[0077]

[0078] Table 2 Design values ​​of optical physical parameters for an optical lens

[0079]

[0080] The surface numbers in Table 2 are assigned according to the surface sequence of each lens. "STO" represents the aperture stop of the lens; "IMA" represents the image plane of the lens; the radius of curvature represents the curvature of the lens surface, with a positive value indicating that the surface bends towards the image plane and a negative value indicating that the surface bends towards the object plane. "Infinity" indicates that the surface is flat and the radius of curvature is infinite; the thickness represents the central axial distance between the current surface and the next surface; the refractive index represents the ability of the material between the current surface and the next surface to deflect light; a blank space indicates that the current position is air and the refractive index is 1; the k value represents the magnitude of the conicity coefficient of the aspherical surface.

[0081] Table 3 Design values ​​of aspherical coefficient in an optical lens

[0082]

[0083] "-1.19E-03" means -1.19 × 10 -3 All other coefficients are represented in this way.

[0084] Furthermore, Figure 2 This is a schematic diagram of the spherical aberration curve of the optical lens provided in Embodiment 1 of this utility model, as shown below. Figure 2 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertical vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). The different linear curves in the figure represent different wavelengths of system imaging (436nm, 486nm, 546nm, 587nm, and 656nm, respectively), derived from... Figure 2It can be seen that the axial aberrations of different wavelengths are all controlled within the range of (-0.03mm, +0.03mm), indicating that the spherical aberration of this fixed-focus lens is well controlled at each wavelength, which can meet the requirements of wide-spectrum applications.

[0085] In summary, the optical lens provided in Embodiment 1 of this utility model constructs a 2G4P optical system. By optimizing the optical power and relative positions of each lens element, a balanced design of compact structure, large field of view, and large target surface size is achieved while meeting imaging quality requirements. This optical lens features a large aperture of approximately F.N. 1.6, which significantly increases light intake in low-light environments, thus ensuring image clarity. Its diagonal field of view reaches 143°, providing a wide viewing angle sufficient to completely cover the driver's face area, meeting the needs of comprehensive condition monitoring. This design not only ensures stable and reliable optical performance but also achieves effective cost and weight control, making it particularly suitable for automotive applications.

[0086] Example 2

[0087] Figure 3 This is a schematic diagram of the structure of the optical lens provided in Embodiment 2 of this utility model, as shown below. Figure 3 As shown, the optical lens provided in Embodiment 2 of this utility model includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106 arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the first lens 101, the second lens 102, and the fifth lens 105 is negative, while the optical power of the third lens 103, the fourth lens 104, and the sixth lens 106 is positive; the field of view of the optical lens is FOV, half of the image height corresponding to the maximum field of view is ImgH, and the total optical length is TTL; wherein, 21°≤FOV×ImgH / TTL≤23°.

[0088] The lens setup is the same as in Embodiment 1, and will not be repeated here.

[0089] As another feasible implementation method, the specific parameters of the optical lens are explained below.

[0090] Table 4. Optical design values ​​for the optical lens in Example 2

[0091]

[0092] Table 5 Design values ​​of optical physical parameters for an optical lens

[0093]

[0094] The surface numbers in Table 5 are assigned according to the surface sequence of each lens. "STO" represents the aperture stop of the lens; "IMA" represents the image plane of the lens; the radius of curvature represents the curvature of the lens surface, with a positive value indicating that the surface bends towards the image plane and a negative value indicating that the surface bends towards the object plane. "Infinity" indicates that the surface is flat and the radius of curvature is infinite; the thickness represents the central axial distance between the current surface and the next surface; the refractive index represents the ability of the material between the current surface and the next surface to deflect light; a blank space indicates that the current position is air and the refractive index is 1; the k value represents the magnitude of the conicity coefficient of the aspherical surface.

[0095] Table 6 Design values ​​of aspherical coefficient in an optical lens

[0096]

[0097] "-5.28E-04" means -5.28 × 10 -4 All other coefficients are represented in this way.

[0098] Furthermore, Figure 4 This is a schematic diagram of the spherical aberration curve of the optical lens provided in Embodiment 2 of this utility model, as shown below. Figure 4 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertical vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). The different linear curves in the figure represent different wavelengths of system imaging (436nm, 486nm, 546nm, 587nm, and 656nm, respectively), derived from... Figure 4 It can be seen that the axial aberrations of different wavelengths are all controlled within the range of (-0.03mm, +0.03mm), indicating that the spherical aberration of this fixed-focus lens is well controlled at each wavelength, which can meet the requirements of wide-spectrum applications.

[0099] In summary, the optical lens provided in Embodiment 2 of this utility model constructs a 2G4P optical system. By optimizing the optical power and relative positions of each lens element, a balanced design of compact structure, large field of view, and large target surface size is achieved while meeting imaging quality requirements. This optical lens features a large aperture of approximately F.N. 1.6, which significantly increases light intake in low-light environments, thus ensuring image clarity. Its diagonal field of view reaches 143°, providing a wide viewing angle sufficient to completely cover the driver's face area, meeting the needs of comprehensive condition monitoring. This design not only ensures stable and reliable optical performance but also achieves effective cost and weight control, making it particularly suitable for automotive applications.

[0100] Example 3

[0101] Figure 5This is a schematic diagram of the structure of the optical lens provided in Embodiment 3 of this utility model, as shown below. Figure 5 As shown, the optical lens provided in Embodiment 3 of this utility model includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, and a sixth lens 106 arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the first lens 101, the second lens 102, and the fifth lens 105 is negative, while the optical power of the third lens 103, the fourth lens 104, and the sixth lens 106 is positive; the field of view of the optical lens is FOV, half of the image height corresponding to the maximum field of view is ImgH, and the total optical length is TTL; wherein, 21°≤FOV×ImgH / TTL≤23°.

[0102] The lens setup is the same as in Embodiment 1, and will not be repeated here.

[0103] As another feasible implementation method, the specific parameters of the optical lens are explained below.

[0104] Table 7. Optical design values ​​for the optical lens in Example 3

[0105]

[0106] Table 8 Design values ​​of optical physical parameters for an optical lens

[0107]

[0108] The surface numbers in Table 8 are assigned according to the surface sequence of each lens. "STO" represents the aperture stop of the lens; "IMA" represents the image plane of the lens; the radius of curvature represents the curvature of the lens surface, with a positive value indicating that the surface bends towards the image plane and a negative value indicating that the surface bends towards the object plane. "Infinity" indicates that the surface is flat and the radius of curvature is infinite; the thickness represents the central axial distance between the current surface and the next surface; the refractive index represents the ability of the material between the current surface and the next surface to deflect light; a blank space indicates that the current position is air and the refractive index is 1; the k value represents the magnitude of the conicity coefficient of the aspherical surface.

[0109] Table 9 Design values ​​of aspherical coefficient in an optical lens

[0110]

[0111] "3.42E-03" means 3.42 × 10 -3 All other coefficients are represented in this way.

[0112] Furthermore, Figure 6 This is a schematic diagram of the spherical aberration curve of the optical lens provided in Embodiment 3 of this utility model, as shown below. Figure 6 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertical vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). The different linear curves in the figure represent different wavelengths of system imaging (436nm, 486nm, 546nm, 587nm, and 656nm, respectively), derived from... Figure 6 It can be seen that the axial aberrations of different wavelengths are all controlled within the range of (-0.03mm, +0.03mm), indicating that the spherical aberration of this fixed-focus lens is well controlled at each wavelength, which can meet the requirements of wide-spectrum applications.

[0113] In summary, the optical lens provided in Embodiment 3 of this utility model constructs a 2G4P optical system. By optimizing the optical power and relative positions of each lens element, a balanced design of compact structure, large field of view, and large target surface size is achieved while meeting imaging quality requirements. This optical lens features a large aperture of approximately F.N. 1.6, which significantly increases light intake in low-light environments, thus ensuring image clarity. Its diagonal field of view reaches 143°, providing a wide viewing angle sufficient to completely cover the driver's face area, meeting the needs of comprehensive condition monitoring. This design not only ensures stable and reliable optical performance but also achieves effective cost and weight control, making it particularly suitable for automotive applications.

[0114] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. 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 this utility model should be included within the scope of protection of this utility model.

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, and a sixth lens arranged sequentially along the optical axis from the object plane to the image plane; The first lens, the second lens, and the fifth lens have negative optical power, while the third lens, the fourth lens, and the sixth lens have positive optical power. The field of view of the optical lens is FOV, half of the image height corresponding to the maximum field of view is ImgH, and the total optical length is TTL; Wherein, 21°≤FOV×ImgH / TTL≤23°.

2. The optical lens according to claim 1, characterized in that, The field of view of the optical lens is FOV, and the effective optical focal length is f; Among them, 45° / mm < FOV / f < 55° / mm.

3. The optical lens according to claim 1, characterized in that, The effective focal length of the optical lens is f, and half of the image height corresponding to the maximum field of view is ImgH; Among them, 0.8 < f / ImgH < 0.

9.

4. The optical lens according to claim 1, characterized in that, The optical power of the first lens is Φ1, the optical power of the second lens is Φ2, the optical power of the third lens is Φ3, the combined optical power of the fourth and fifth lenses is Φ45, the optical power of the sixth lens is Φ6, and the optical power of the optical lens is Φ. Among them, -0.59<Φ1 / Φ<-0.39, -0.59<Φ2 / Φ<-0.39, 0.34<Φ3 / Φ<0.58, -0.03<Φ45 / Φ<0.0075, 0<Φ6 / Φ<0.

55.

5. The optical lens according to claim 3, characterized in that, The refractive index of the third lens is Nd3, where 1.7 <Nd3<2.05; The fourth lens and the fifth lens are cemented together. The Abbe number of the fourth lens is Vd4, and the Abbe number of the fifth lens is Vd5, wherein 55 < Vd4 < 61.7, 19.3 < Vd5 < 21.

3. The Abbe number of the sixth lens is Vd6, where 55 < Vd6 < 59.

7.

6. The optical lens according to claim 1, characterized in that, The total optical length of the optical lens is TTL, and the effective optical focal length is f; Where 7≤TTL / f≤8.

7. The optical lens according to claim 1, characterized in that, The optical lens has a back focal length of BFL and a total optical length of TTL. Among them, BFL / TTL > 0.

18.

8. The optical lens according to claim 1, characterized in that, The first lens includes a first object-side surface near the object plane and a first image-side surface near the image plane. The first object-side surface is convex, and the first image-side surface is concave. The second lens includes a second object-side surface near the object plane and a second image-side surface near the image plane. The second object-side surface is concave, and the second image-side surface is either convex or concave. The third lens includes a third object-side surface near the object plane and a third image-side surface near the image plane. The third object-side surface is convex, and the third image-side surface is convex. The fourth lens includes a fourth object-side surface near the object plane and a fourth image-side surface near the image plane. The fourth object-side surface is convex, and the fourth image-side surface is convex. The fifth lens includes a fifth object-side surface near the object plane and a fifth image-side surface near the image plane. The fifth object-side surface is concave, and the fifth image-side surface is concave. The sixth lens includes a sixth object-side surface near the object plane and a sixth image-side surface near the image plane. The sixth object-side surface is convex, and the sixth image-side surface is convex.

9. The optical lens according to claim 1, characterized in that, The first lens and the third lens are glass spherical lenses, while the second lens, the fourth lens, the fifth lens, and the sixth lens are plastic aspherical lenses.

10. The optical lens according to claim 1, characterized in that, The optical lens also includes an aperture stop and a filter; The aperture stop is disposed in the optical path between the third lens and the fourth lens; The filter is disposed in the optical path between the sixth lens and the image plane.

Images