Optical lens

Abstract

The present invention provides an optical lens, which has a total of five lenses and successively includes, along the optical axis from the object side to the imaging surface: a first lens with a negative optical power, whose object side is convex and whose image side is concave; a second lens with a negative optical power, whose object side is convex and whose image side is concave; a third lens with a positive optical power, whose object side and image side are both convex; a fourth lens with a positive optical power, whose object side is concave and whose image side is convex; a fifth lens with a positive optical power, whose object side and image side are both convex; wherein, the true image height IH corresponding to the maximum field of view angle of the optical lens, the effective focal length f of the optical lens and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.97 < (IH / 2) / (f×θ) < 1.07. The optical lens provided by the present invention has one or more advantages such as a large field of view angle, small distortion, large aperture, and high imaging quality through specific surface shape matching and reasonable optical power distribution.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and particularly to an optical lens. Background Art

[0002] Nowadays, lidar is widely used in detecting the three-dimensional coordinates and ranging of objects. The lidar includes a controller, a light source and a receiving device. The controller controls the light source to emit a light beam. After the light beam encounters a target object, it undergoes diffuse reflection. The receiving device is used to receive the reflected light beam, and the relevant information of the target object, such as parameters like target distance, azimuth, height, speed, attitude, and even shape, is determined based on the information of the emitted light beam and the reflected light beam. Lidar is widely used in autonomous driving vehicles, drones, autonomous robots, satellites, rockets, etc.

[0003] As a key component of lidar, the optical lens can receive and process the reflected light. Currently, the optical lenses of lidar have problems such as large distortion and low imaging quality, which cannot meet the market demand. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide an optical lens with excellent imaging quality.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An optical lens, comprising a total of five lenses, which sequentially include from the object side to the imaging surface along the optical axis:

[0007] A first lens with negative optical power, its object side is convex, and its image side is concave;

[0008] A second lens with negative optical power, its object side is convex, and its image side is concave;

[0009] A third lens with positive optical power, both its object side and image side are convex;

[0010] A fourth lens with positive optical power, its object side is concave, and its image side is convex;

[0011] A fifth lens with positive optical power, both its object side and image side are convex;

[0012] Wherein, the true image height IH corresponding to the maximum field of view angle of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.97 < (IH / 2) / (f×θ) < 1.07.

[0013] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 14 < TTL / f < 16.5; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3.9 < TTL / IH < 4.9.

[0014] Further preferably, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 135° < FOV / Fno < 150°; the combined focal length f12 of the first lens and the second lens and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: -0.51 < f12 / f345 < -0.46; the chief ray angle of incidence CRA at the maximum image height of the optical lens satisfies: 1.6° < CRA < 2.8°.

[0015] Further preferably, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 3.2 < IH / f < 3.7; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 1.8 < BFL / f < 2.2.

[0016] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -8 < f1 / f < -5; the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.34 < (R1 - R2) / (R1 + R2) < 0.55.

[0017] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.3 < f2 / f < -2.8; the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: 0.74 < (R3 - R4) / (R3 + R4) < 0.96.

[0018] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.8 < f3 / f < 3.4; the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: 0.48 < (R5 + R6) / (R5 - R6) < 0.63.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 20 < f4 / f < 29; the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: 0.03 < (R7 - R8) / (R7 + R8) < 0.09.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 4.4 < f5 / f < 5; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: 0.26 < (R9 + R10) / (R9 - R10) < 0.68.

[0021] Further preferably, the clear aperture radius d7 of the object side surface of the fourth lens and the sagittal height Sag7 of the clear aperture of the object side surface of the fourth lens satisfy: -0.33 < Sag7 / d7 < -0.29; the clear aperture radius d8 of the image side surface of the fourth lens and the sagittal height Sag8 of the clear aperture of the image side surface of the fourth lens satisfy: -0.43 < Sag8 / d8 < -0.32.

[0022] The optical lens provided by the present invention adopts five lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and enable the lens to have one or more advantages such as a large field of view angle, small distortion, large aperture, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0025] Figure 2 is the F-Theta distortion curve of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 3 is the MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 4 is the relative illumination curve graph of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 5 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0029] Figure 6 is the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

[0030] Figure 7 is the MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 8 is the relative illumination curve graph of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 9 It is a schematic structural diagram of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 10 It is the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0034] Figure 11 It is the MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 12 It is the relative illumination curve graph of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 13 It is a schematic structural diagram of the optical lens in Embodiment 4 of the present invention.

[0037] Figure 14 It is the F-Theta distortion curve of the optical lens in Embodiment 4 of the present invention.

[0038] Figure 15 It is the MTF curve graph of the optical lens in Embodiment 4 of the present invention.

[0039] Figure 16 It is the relative illumination curve graph of the optical lens in Embodiment 4 of the present invention.

[0040] Figure 17 It is a schematic structural diagram of the optical lens in Embodiment 5 of the present invention.

[0041] Figure 18 It is the F-Theta distortion curve of the optical lens in Embodiment 5 of the present invention.

[0042] Figure 19 It is the MTF curve graph of the optical lens in Embodiment 5 of the present invention.

[0043] Figure 20 It is the relative illumination curve graph of the optical lens in Embodiment 5 of the present invention.

[0044] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0045] To better understand the present application, more detailed descriptions of various aspects of the present application will be made with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0046] It should be noted that in this specification, the expressions such as first, second, third, etc. are only used to distinguish one feature from another, and do not represent any limitation on the features. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0047] In the drawings, for ease of illustration, the thickness, size, and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only examples and are not drawn to an exact scale.

[0048] In this context, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object being photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0049] It should also be understood that the terms "comprises", "comprising", "has", "including" and / or "including having", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when an expression such as "at least one of..." appears after the list of listed features, it modifies the entire list of listed features, rather than modifying the individual elements in the list. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0051] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0052] The optical lens provided by the embodiment of the present invention has a total of five lenses, which are, in order from the object side to the imaging surface along the optical axis, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens.

[0053] In some embodiments, the first lens may have a negative optical power, with its object side being convex and its image side being concave. The second lens may have a negative optical power, with its object side being convex and its image side being concave. The third lens may have a positive optical power, with both its object side and image side being convex. The fourth lens may have a positive optical power, with its object side being concave and its image side being convex. The fifth lens may have a positive optical power, with both its object side and image side being convex.

[0054] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the second lens and the third lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image. In addition, when the diaphragm is located between the second lens and the third lens, the diaphragm can reasonably distribute the functions of the first lens to the fifth lens. For example, the first lens and the second lens can be used to receive light to a greater extent, and the third lens to the fifth lens can be used to correct aberrations, which is beneficial to balancing the structure of the entire optical system. In addition, when the diaphragm is located between the second lens and the third lens, it is convenient to correct the diaphragm aberration.

[0055] In some embodiments, the optical lens may further include a filter, and the filter is disposed between the fifth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0056] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.97 < (IH / 2) / (f×θ) < 1.07. Satisfying the above range is beneficial to realizing the ultra-wide angle characteristic of the optical lens and can control the optical lens to have a small distortion.

[0057] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 14 < TTL / f < 16.5. Satisfying the above range can effectively limit the length of the lens and is beneficial to realizing the miniaturization of the optical lens. More specifically, 14.24 < TTL / f < 16.02.

[0058] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3.9 < TTL / IH < 4.9. Satisfying the above range ensures that the lens has a larger image surface under the condition of the same total length, can match a larger-sized imaging chip to achieve high-definition imaging, and can better achieve the balance of the small total length and the large image surface of the lens. More specifically, 3.98 < TTL / IH < 4.9.

[0059] In some embodiments, the maximum field of view (FOV) of the optical lens and the f-number (Fno) of the optical lens satisfy: 135° < FOV / Fno < 150°. Meeting the above range defines that the optical lens has a suitable field of view and f-number, enabling it to collect light at large angles and obtain good imaging quality. More specifically, 136.68° < FOV / Fno < 148.16°.

[0060] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: -0.51 < f12 / f345 < -0.46. Meeting the above range, by reasonably setting the focal length relationship of the lens groups before and after the aperture, it is beneficial to balance various aberrations generated by the lens groups and improve the overall imaging quality.

[0061] In some embodiments, the chief ray angle (CRA) at the maximum image height of the optical lens satisfies: 1.6° < CRA < 2.8°. Meeting the above range, having a small CRA, good brightness uniformity, small chromatic aberration and distortion, making the image undistorted and having good imaging quality.

[0062] In some embodiments, the true image height (IH) corresponding to the maximum field of view of the optical lens and the effective focal length (f) of the optical lens satisfy: 3.2 < IH / f < 3.7. Meeting the above range, controlling the image height and focal length of the optical lens within a reasonable range helps the optical lens have the characteristic of a large image plane and improves the imaging quality. More specifically, 3.24 < IH / f < 3.7.

[0063] In some embodiments, the effective focal length (f) of the optical lens and the back focal length (BFL) of the optical lens satisfy: 1.8 < BFL / f < 2.2. Meeting the above range defines that the optical lens has a suitable back focus, facilitating the reasonable arrangement of the positions of the lenses and reducing the processing and assembly difficulty. More specifically, 1.82 < BFL / f < 2.18.

[0064] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -8 < f1 / f < -5; the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.34 < (R1 - R2) / (R1 + R2) < 0.55. Meeting the above range, by setting the first lens to have a negative refractive power and a suitable surface shape, it is beneficial for the first lens to receive light at a larger angle and collect as much light as possible into the subsequent optical system, achieving a large field of view while increasing the light flux. More specifically, -7.99 < f1 / f < -5.14.

[0065] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.3 < f2 / f < -2.8; the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: 0.74 < (R3 - R4) / (R3 + R4) < 0.96. Satisfying the above ranges enables the second lens to have a negative optical power and a suitable surface shape, and can share the negative optical power at the front end of the optical lens, thereby facilitating the avoidance of excessive light deflection caused by overly concentrated optical power of the first lens and reducing the difficulty of chromatic aberration correction of the optical lens. More specifically, -3.28 < f2 / f < -2.86.

[0066] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.8 < f3 / f < 3.4; the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 0.48 < (R5 + R6) / (R5 - R6) < 0.63. Satisfying the above ranges defines that the third lens has an appropriate positive optical power and a suitable surface shape, has the effect of converging light, reduces the height of peripheral light, and is beneficial to reducing the aperture of the rear lens. More specifically, 2.83 < f3 / f < 3.38.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 20 < f4 / f < 29; the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.03 < (R7 - R8) / (R7 + R8) < 0.09. Satisfying the above ranges is beneficial to converging light while correcting the field curvature and distortion of the optical lens, and improving the imaging quality of the optical lens. More specifically, 20 < f4 / f < 28.11.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 4.4 < f5 / f < 5; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: 0.26 < (R9 + R10) / (R9 - R10) < 0.68. Satisfying the above ranges sets the fifth lens to have a positive refractive power and a suitable surface shape, which is beneficial to light convergence, enables the light trend to smoothly transition to the rear, reduces the height of the light incident on the rear, avoids light energy loss caused by too large a chief ray angle between the large field-of-view light and the chip when reaching the imaging surface, is beneficial to improving the illuminance of the edge field of view, and is beneficial to achieving a short optical total length. More specifically, 4.49 < f5 / f < 4.98.

[0069] In some embodiments, the clear aperture semi-diameter d7 of the object side surface of the fourth lens and the sagittal height Sag7 of the clear aperture of the object side surface of the fourth lens satisfy: -0.33 < Sag7 / d7 < -0.29; the clear aperture semi-diameter d8 of the image side surface of the fourth lens and the sagittal height Sag8 of the clear aperture of the image side surface of the fourth lens satisfy: -0.43 < Sag8 / d8 < -0.32. Meeting the above ranges helps to control the trend of light rays in the peripheral field of view and highlight the detailed information of the central field of view of the optical lens.

[0070] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis satisfy: 0.41 < ∑CT / TTL < 0.5. Meeting the above range can effectively compress the total length of the optical lens and is beneficial to the structural design and production process of the optical lens.

[0071] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis and the effective focal length f of the optical lens satisfy: 6.5 < ΣCT / f < 7.5. Meeting the above range can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens. More specifically, 6.68 < ΣCT / f < 7.37.

[0072] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 10 < R3 / f < 60; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.4 < R4 / f < 1.7. Meeting the above range has the effect of diverging light rays. At the same field of view angle, it further diverges the light rays emerging from the image side surface of the first lens, can disperse the central light rays and peripheral light rays of each field of view, and enables the rear optical system to have a larger light receiving surface to receive the light rays emerging from the image side surface of the second lens, achieving a larger light input and being beneficial to increasing the relative illuminance. More specifically, 10.03 < R3 / f < 58.38; 1.41 < R4 / f < 1.61.

[0073] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -4.6 < R7 / f < -4.2; the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -4.1 < R8 / f < -3.6. Meeting the above range reduces the difficulty of peripheral field of view distortion correction, ensures that the lens has a small distortion while achieving a large field of view angle, and improves the overall imaging quality. More specifically, -4.55 < R7 / f < -4.29; -4.05 < R8 / f < -3.63.

[0074] In some embodiments, the optical lens satisfies the following conditional expressions: 1.4 mm < f < 1.6 mm; 185° < FOV < 205°; 1 mm < EPD < 1.2 mm; 20 mm < TTL < 24 mm; 1.3 < Fno < 1.4; 4.8 mm < IH < 5.5 mm; 2.6 mm < BFL < 3.2 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, FNO represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above ranges, the optical lens has at least one or more advantages such as a large field of view angle and a large aperture. More specifically, 1.45 mm < f < 1.54 mm; 1.04 mm < EPD < 1.11 mm; 21.62 mm < TTL < 23.7 mm; 1.34 < Fno < 1.4; 2.68 mm < BFL < 3.18 mm; 191° < FOV < 201°; 4.89 mm < IH < 5.44 mm.

[0075] In some embodiments, the lens material in the optical lens provided by the present invention may be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. Additionally, when the lens material is glass, due to the low dispersion characteristic of the glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. In the optical lens provided by the present invention, the fourth lens and the fifth lens adopt plastic materials, and the first lens, the second lens, and the third lens adopt glass materials. Adopting a glass-plastic hybrid structure is beneficial to improving the thermal stability performance of the optical lens.

[0076] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens may adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the fourth lens and the fifth lens of the present invention adopt aspherical lenses; the first lens, the second lens, and the third lens adopt spherical lenses.

[0077] In various embodiments of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0078] ;

[0079] where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, and F are the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients, respectively.

[0080] The present invention will be further described below with reference to multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are partially different. For specific differences, please refer to the parameter tables of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0081] Embodiment 1

[0082] Please refer to Figure 1 , which shows a schematic structural diagram of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 sequentially includes, along the optical axis from the object side to the imaging surface: a first lens L1, a second lens L2, a diaphragm ST, a third lens L3, a fourth lens L4, a fifth lens L5, a filter G1, and a protective glass G2.

[0083] Among them, the first lens L1 has a negative optical power. Its object side S1 is a convex surface, and its image side S2 is a concave surface;

[0084] The second lens L2 has a negative optical power. Its object side S3 is a convex surface, and its image side S4 is a concave surface;

[0085] The third lens L3 has a positive optical power. Its object side S5 and image side S6 are both convex surfaces;

[0086] The fourth lens L4 has a positive optical power. Its object side S7 is a concave surface, and its image side S8 is a convex surface;

[0087] The fifth lens L5 has a positive optical power. Its object side S9 and image side S10 are both convex surfaces;

[0088] The object side S11 and image side S12 of the filter G1 are both flat surfaces;

[0089] The object side S13 and image side S14 of the protective glass G2 are both flat surfaces;

[0090] The imaging surface S15 is a flat surface.

[0091] The fourth lens L4 and the fifth lens L5 are plastic aspherical lenses; the first lens L1, the second lens L2, and the third lens L3 are all glass spherical lenses.

[0092] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1.

[0093] Table 1

[0094]

[0095] The surface profile parameters of the aspherical lens of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0096] Table 1-2

[0097]

[0098] In this embodiment, the F-Theta distortion curve, MTF curve graph, and relative illumination curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 , Figure 4 shown.

[0099] Figure 2 shows the F-Theta distortion curve of Embodiment 1, which represents the F-Theta distortion of light rays with different wavelengths at different image heights on the imaging surface. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the F-Theta distortion of the optical lens is controlled within -2% to 1%, indicating that the optical lens can correct distortion well.

[0100] Figure 3 shows the MTF (Modulation Transfer Function) curve graph of Embodiment 1, which represents the modulation of the lens imaging at different spatial frequencies in each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of this embodiment is above 0.35 within the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0101] Figure 4 shows the relative illumination curve of Embodiment 1, which represents the relative illumination values at different field of view angles on the imaging surface. The horizontal axis represents the semi-field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). It can be seen from the figure that the relative illumination value of the optical lens is still greater than 75% at the maximum semi-field angle, indicating that the optical lens has good relative illumination.

[0102] Embodiment 2

[0103] Please refer to Figure 5 , which shows the structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0104] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2.

[0105] Table 2

[0106]

[0107] The surface type parameters of the aspherical lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0108] Table 2-2

[0109]

[0110] In this embodiment, the F-Theta distortion curve, MTF curve graph, and relative illuminance curve graph of the optical lens 200 are respectively as Figure 6 , Figure 7 , Figure 8 shown.

[0111] From Figure 6 it can be seen that the F-Theta distortion of the optical lens is controlled within 0 to 5%, indicating that the optical lens can correct the distortion well.

[0112] From Figure 7 it can be seen that the MTF value of this embodiment is above 0.2 within the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0113] From Figure 8 it can be seen that at the maximum half field angle, the relative illuminance value of the optical lens is still greater than 60%, indicating that the optical lens has good relative illuminance.

[0114] Embodiment 3

[0115] Please refer to Figure 9 , which shows the structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main difference is that: the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0116] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3.

[0117] Table 3

[0118]

[0119] The surface type parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0120] Table 3-2

[0121]

[0122] In this embodiment, the F-Theta distortion curve, MTF curve graph, and relative illuminance curve graph of the optical lens 300 are respectively as follows Figure 10 , Figure 11 , Figure 12 shown.

[0123] It can be seen from Figure 10 that the F-Theta distortion of the optical lens is controlled within -2% to 2%, indicating that the optical lens can correct distortion well.

[0124] It can be seen from Figure 11 that the MTF value of this embodiment is above 0.25 within the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0125] It can be seen from Figure 12 that the relative illuminance value of the optical lens at the maximum half field angle is still greater than 60%, indicating that the optical lens has good relative illuminance.

[0126] Embodiment 4

[0127] Please refer to Figure 13 , which shows the structural schematic diagram of the optical lens 400 provided in Embodiment 4 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0128] The relevant parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4.

[0129] Table 4

[0130]

[0131] The surface type parameters of the aspherical lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0132] Table 4-2

[0133]

[0134] In this embodiment, the F-Theta distortion curve, MTF curve graph, and relative illuminance curve graph of the optical lens 400 are respectively as follows Figure 14 , Figure 15 , Figure 16 shown.

[0135] It can be seen from Figure 14It can be seen that the F-Theta distortion of the optical lens is controlled within 0-6%, indicating that the optical lens can correct distortion well.

[0136] From Figure 15 it can be seen that the MTF value of this embodiment is above 0.25 within the entire field of view. In the range of 0-120 lp / mm, the MTF curve decreases uniformly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0137] From Figure 16 it can be seen that the relative illumination value of the optical lens is still greater than 65% at the maximum semi-field angle, indicating that the optical lens has good relative illumination.

[0138] Embodiment 5

[0139] Please refer to Figure 17 , which shows the structural schematic diagram of the optical lens 500 provided in Embodiment 5 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0140] The relevant parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5.

[0141] Table 5

[0142]

[0143] The surface type parameters of the aspherical lens of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0144] Table 5-2

[0145]

[0146] In this embodiment, the F-Theta distortion curve, MTF curve diagram, and relative illumination curve diagram of the optical lens 500 are respectively as shown in Figure 18 , Figure 19 , Figure 20 .

[0147] From Figure 18 it can be seen that the F-Theta distortion of the optical lens is controlled within 0-6%, indicating that the optical lens can correct distortion well.

[0148] From Figure 19It can be seen that the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0149] From Figure 20 it can be seen that at the maximum half field of view angle, the relative illumination value of the optical lens is still greater than 58%, indicating that the optical lens has good relative illumination.

[0150] Please refer to Table 6 for the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the true image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, and the values corresponding to each conditional formula in each embodiment.

[0151] Table 6

[0152]

[0153] Combining the above embodiments, the optical lens provided by the present invention uses five lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, enabling the lens to have one or more advantages such as a large field of view angle, small distortion, large aperture, and high imaging quality.

[0154] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0155] The above-described embodiments merely represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. An optical lens, consisting of five lenses in total, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is convex and whose image side is concave; A second lens with a negative optical power, whose object side is convex and whose image side is concave; A third lens with a positive optical power, whose object side and image side are both convex; A fourth lens with a positive optical power, whose object side is concave and whose image side is convex; A fifth lens with a positive optical power, whose object side and image side are both convex; Wherein, the true image height IH corresponding to the maximum field of view angle of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.97 < (IH / 2) / (f×θ) < 1.07; The maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 135° < FOV / Fno < 150°; 1.3 < Fno < 1.4, where Fno represents the aperture value of the optical lens.

2. The optical lens according to claim 1, wherein The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 14 < TTL / f < 16.5; the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3.9 < TTL / IH < 4.

9.

3. The optical lens according to claim 1, wherein The maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 136.68° < FOV / Fno < 148.16°; 1.34 < Fno < 1.4, where Fno represents the aperture value of the optical lens; the combined focal length f12 of the first lens and the second lens and the combined focal lengths f345 of the third lens, the fourth lens, and the fifth lens satisfy: -0.51 < f12 / f345 < -0.46; the chief ray angle of incidence CRA at the maximum image height of the optical lens satisfies: 1.6° < CRA < 2.8°.

4. The optical lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 3.2 < IH / f < 3.7; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 1.8 < BFL / f < 2.

2.

5. The optical lens according to claim 1, wherein The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -8 < f1 / f < -5; the curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: 0.34 < (R1 - R2) / (R1 + R2) < 0.

55.

6. The optical lens according to claim 1, wherein The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.3 < f2 / f < -2.8; the curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side of the second lens satisfy: 0.74 < (R3 - R4) / (R3 + R4) < 0.

96.

7. The optical lens according to claim 1, wherein The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.8 < f3 / f < 3.4; the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 0.48 < (R5 + R6) / (R5 - R6) < 0.

63.

8. The optical lens according to claim 1, wherein, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 20 < f4 / f < 29; the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.03 < (R7 - R8) / (R7 + R8) < 0.

09.

9. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 4.4 < f5 / f < 5; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: 0.26 < (R9 + R10) / (R9 - R10) < 0.

68.

10. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d7 of the object side surface of the fourth lens and the sagittal height Sag7 of the clear aperture of the object side surface of the fourth lens satisfy: -0.33 < Sag7 / d7 < -0.29; the clear aperture semi-diameter d8 of the image side surface of the fourth lens and the sagittal height Sag8 of the clear aperture of the image side surface of the fourth lens satisfy: -0.43 < Sag8 / d8 < -0.32.

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