Optical lens

Abstract

The invention provides an optical lens, which comprises five lenses from an object side to an imaging surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface and the image side surface of the third lens are convex surfaces; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has positive focal power, and the object side surface and the image side surface of the fifth lens are convex surfaces; wherein the real image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens and the radian value theta of the maximum half field angle of the optical lens meet the following conditions: 0.97 lt; (IH / 2) / (f * theta) lt; 1.07). According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of large field angle, small distortion, large aperture, high imaging quality and the like.

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. A 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 relevant information about 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, an 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: An optical lens, comprising a total of five lenses, which sequentially include from the object side to the imaging surface along the optical axis: A first lens with negative optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose object side is convex and whose image side is concave; A third lens with positive optical power, whose object side and image side are both convex; A fourth lens with positive optical power, whose object side is concave and whose image side is convex; A fifth lens with 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.

[0006] 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.

[0007] 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 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°.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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 curvature radius R9 of the object side surface of the fifth lens and the curvature radius R10 of the image side surface of the fifth lens satisfy: 0.26 < (R9 + R10) / (R9 - R10) < 0.68.

[0014] Further preferably, 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.

[0015] The optical lens provided by the present invention uses 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

[0016] 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, where: Figure 1 It is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 2 It is the F-Theta distortion curve of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 It is the MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 It is the relative illumination curve graph of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 It is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0021] Figure 6 It is the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 7 It is the MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 8 It is the relative illumination curve graph of the optical lens in Embodiment 2 of the present invention.

[0024] Fig. 9 It is a schematic structural diagram of the optical lens in Embodiment 3 of the present invention.

[0025] Fig.10 It is the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0026] Fig.11This is the MTF curve diagram of the optical lens in Example 3 of the present invention.

[0027] Fig.12 This is a relative illumination curve diagram of the optical lens in Example 3 of the present invention.

[0028] Fig.13 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0029] Fig.14 : is the F-Theta distortion curve of the optical lens in Example 4 of the present invention.

[0030] Fig.15 This is the MTF curve diagram of the optical lens in Example 4 of the present invention.

[0031] Fig.16 This is a relative illumination curve diagram of the optical lens in Example 4 of the present invention.

[0032] Fig.17 Schematic diagram of the structure of the optical lens in Example 5 of the present invention.

[0033] Fig.18 : is the F-Theta distortion curve of the optical lens in Example 5 of the present invention.

[0034] Fig.19 This is the MTF curve diagram of the optical lens in Example 5 of the present invention.

[0035] Fig. 20 This is a relative illumination curve diagram of the optical lens in Example 5 of the present invention.

[0036] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0037] In order to better understand the present application, a more detailed description will be made of various aspects of the present application 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 are not intended to 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.

[0038] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0039] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0040] In this article, 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 is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0041] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0042] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0043] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0044] The optical lens provided by the embodiment of the present invention comprises five lenses in total, which are a first lens, a second lens, a third lens, a fourth lens and a fifth lens in order from the object side to the imaging surface along the optical axis.

[0045] 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.

[0046] In some embodiments, the optical lens may further include a diaphragm, which 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 imaging. Additionally, 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. Furthermore, when the diaphragm is located between the second lens and the third lens, it is convenient to correct the diaphragm aberration.

[0047] In some embodiments, the optical lens may further include a filter, which 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.

[0048] 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.

[0049] 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.

[0050] 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, with the same total length of the lens, it has a larger image plane, can match a larger-sized imaging chip to achieve high-definition imaging, and can better achieve the balance between the small total length and the large image plane of the lens. More specifically, 3.98 < TTL / IH < 4.9.

[0051] 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 an appropriate field of view and f-number, can collect light at large angles, and obtain good imaging quality. More specifically, 136.68° < FOV / Fno < 148.16°.

[0052] 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.

[0053] 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, it has a small CRA, good brightness uniformity, small chromatic aberration and distortion, making the picture non-deformed and having good imaging quality.

[0054] 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 to have the characteristic of a large image plane and improve the imaging quality. More specifically, 3.24 < IH / f < 3.7.

[0055] 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 an appropriate back focus, which is convenient for reasonably arranging the positions of the lenses and reducing the processing and assembly difficulty. More specifically, 1.82 < BFL / f < 2.18.

[0056] 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 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. Meeting the above range, by setting the first lens to have a negative refractive power and an appropriate surface shape, it is beneficial for the first lens to accommodate light at a larger angle and collect as much light as possible into the rear optical system, realizing a large field of view while increasing the light flux. More specifically, -7.99 < f1 / f < -5.14.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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 an angle between the main light ray of 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.

[0061] 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 semi-diameter 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 semi-diameter of the image side surface of the fourth lens satisfy: -0.43 < Sag8 / d8 < -0.32. Satisfying the above ranges helps to control the trend of light rays in the marginal field of view and highlight the detailed information of the central field of view of the optical lens.

[0062] 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. Satisfying 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.

[0063] 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. Satisfying 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.

[0064] In some embodiments, the curvature radius 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 curvature radius 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. Satisfying the above range has the effect of diverging light rays. At the same field of view angle, the light rays emerging from the image side surface of the first lens are further diverged, and the central rays and marginal rays of each field of view can be dispersed, enabling 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 illumination. More specifically, 10.03 < R3 / f < 58.38; 1.41 < R4 / f < 1.61.

[0065] In some embodiments, the curvature radius 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 curvature radius 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. Satisfying the above range reduces the difficulty of correcting the marginal field of view distortion, 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.

[0066] 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.

[0067] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. On the other hand, 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. The use of a glass-plastic hybrid structure is beneficial to improving the thermal stability performance of the optical lens.

[0068] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens can 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.

[0069] 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 equations: ; where z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the 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.

[0070] The present invention is further described below in multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different. For specific differences, please refer to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate 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.

[0071] Example 1 See also Figure 1 , shown is a schematic diagram of the structure of the optical lens 100 provided in Example 1 of the present invention, and the optical lens 100 includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a filter G1 and a protective glass G2.

[0072] The first lens L1 has negative refractive power, its object side surface S1 is convex, and its image side surface S2 is concave; The second lens L2 has negative refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave; The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex; The fourth lens L4 has positive refractive power, its object-side surface S7 is concave, and its image-side surface S8 is convex; The fifth lens L5 has positive refractive power, and its object-side surface S9 and image-side surface S10 are both convex surfaces; The object side surface S11 and the image side surface S12 of the filter G1 are both planes; The object side surface S13 and the image side surface S14 of the protective glass G2 are both planes; The imaging surface S15 is a plane.

[0073] 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 glass spherical lenses.

[0074] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1.

[0075] Table 1 The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0076] Table 1-2 In this embodiment, the F-Theta distortion curve, MTF curve, and relative illumination curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 shown.

[0077] Figure 2 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion of light of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the F-Theta distortion of the optical lens is controlled within -2%~1%, indicating that the optical lens can correct the distortion well.

[0078] Figure 3 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under 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 in the entire field of view, and in the range of 0 to 120 lp / mm, the MTF curve decreases evenly 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 conditions.

[0079] Figure 4 The relative illumination curve of Example 1 is shown, which represents the relative illumination values ​​at different field angles on the imaging plane, with the horizontal axis representing the half field angle (unit: °) and the vertical axis representing 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 half field angle, indicating that the optical lens has good relative illumination.

[0080] Example 2 See also Figure 5 , shown is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0081] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2.

[0082] Table 2 The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0083] Table 2-2 In this embodiment, the F-Theta distortion curve, MTF curve, and relative illumination curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 shown.

[0084] from Figure 6 It can be seen that the F-Theta distortion of the optical lens is controlled within 0~5%, indicating that the optical lens can correct the distortion well.

[0085] from Figure 7 It can be seen that the MTF value of this embodiment is above 0.2 in the whole field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0086] from Figure 8 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 60%, indicating that the optical lens has good relative illumination.

[0087] Example 3 See also Fig. 9 , shown is a schematic diagram of the structure of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0088] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3.

[0089] Table 3 The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0090] Table 3-2 In this embodiment, the F-Theta distortion curve, MTF curve, and relative illumination curve of the optical lens 300 are respectively as follows: Fig.10 , Fig.11 , Fig.12 shown.

[0091] from Fig.10 It can be seen that the F-Theta distortion of the optical lens is controlled within -2%~2%, indicating that the optical lens can correct the distortion well.

[0092] from Fig.11It can be seen that the MTF value of this embodiment is above 0.25 in the whole field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0093] from Fig.12 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 60%, indicating that the optical lens has good relative illumination.

[0094] Example 4 See also Fig.13 , shown is a schematic diagram of the structure of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0095] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4.

[0096] Table 4 The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0097] Table 4-2 In this embodiment, the F-Theta distortion curve, MTF curve, and relative illumination curve of the optical lens 400 are respectively as follows: Fig.14 , Fig.15 , Fig.16 shown.

[0098] from Fig.14 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 the distortion well.

[0099] from Fig.15 It can be seen that the MTF value of this embodiment is above 0.25 in the whole field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0100] from Fig.16 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 65%, indicating that the optical lens has good relative illumination.

[0101] Example 5 See also Fig.17, shown is a schematic diagram of the structure of an optical lens 500 provided in Example 5 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0102] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5.

[0103] Table 5 The surface parameters of the aspheric lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0104] Table 5-2 In this embodiment, the F-Theta distortion curve, MTF curve, and relative illumination curve of the optical lens 500 are respectively as follows: Fig.18 , Fig.19 , Fig. 20 shown.

[0105] from Fig.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 the distortion well.

[0106] from Fig.19 It can be seen that the MTF value of this embodiment is above 0.3 in the whole field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0107] from Fig. 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.

[0108] Please refer to Table 6, which shows 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 real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0109] Table 6 In summary of the above embodiments, 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 is possible to improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages such as a large field of view, small distortion, a large aperture, and high imaging quality.

[0110] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0111] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, comprising five lenses, characterized in that: It successively includes, from the object side to the imaging surface along the optical axis: A first lens with negative optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose object side is convex and whose image side is concave; A third lens with positive optical power, whose object side and image side are both convex; A fourth lens with positive optical power, whose object side is concave and whose image side is convex; A fifth lens with 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.

2. The optical lens according to claim 1, characterized in that: 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.

3. The optical lens according to claim 1, characterized in that: 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 lengths f345 of the third lens, the fourth lens, and the fifth lens satisfy: -0.51 < f12 / f345 < -0.46; The principal ray incident angle 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, characterized in that: 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, characterized in that: 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, characterized in that: 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 of the third lens and the curvature radius R6 of the image side of the third lens satisfy: 0.48 < (R5 + R6) / (R5 - R6) < 0.

63.

8. The optical lens according to claim 1, characterized in that: 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 of the fourth lens and the curvature radius R8 of the image side 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 curvature radius R9 of the object side surface of the fifth lens and the curvature radius 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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