Optical lens

Abstract

The application provides an optical lens, which has seven lenses with optical power, and sequentially comprises, along an optical axis from an object side to an imaging surface, a first lens with negative optical power, whose object side surface is a concave surface and whose image side surface is a concave surface; a second lens with negative optical power, whose object side surface is a concave surface and whose image side surface is a concave surface; a third lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a convex surface; a fourth lens with negative optical power; a fifth lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a convex surface; a sixth lens with negative optical power, whose object side surface is a concave surface and whose image side surface is a convex surface; and a seventh lens with positive optical power, whose object side surface is a convex surface. The optical lens provided by the application has one or more advantages of a large image surface, a large field of view, miniaturization, small CAs, high collimation performance and the like, by virtue of specific surface shape collocation and reasonable optical power distribution.

Description

Technical Field

[0001] This invention relates to the technical field of imaging lenses, and in particular to an optical lens. Background Technology

[0002] Today, lidar is widely used for detecting the three-dimensional coordinates and ranging of objects. A lidar system includes a controller, a light source, and a receiver. The controller controls the light source to emit a light beam. When the beam encounters a target object, it undergoes diffuse reflection. The receiver receives the reflected beam and uses the information from both the emitted and reflected beams to determine relevant information about the target object, such as its distance, orientation, height, speed, attitude, and even shape. LiDAR is widely used in autonomous vehicles, drones, autonomous robots, lawnmowers, and more.

[0003] As a key component of lidar, the optical lens receives and processes reflected light. With the ever-increasing performance requirements of lidar applications, optical lens parameters need to evolve towards larger apertures, wider fields of view, and lower aberrations to meet the growing demands for high-precision, wide-coverage detection. Currently, lidar optical lenses suffer from low image quality, failing to meet market demands. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0005] This invention provides an optical lens comprising seven lenses with optical power, arranged sequentially along the optical axis from the object side to the imaging plane: The first lens with negative optical power has a concave object side and a concave image side. A second lens with negative optical power has a concave object side and a concave image side. A third lens with positive optical power has a convex object-side surface and a convex image-side surface. A fourth lens with negative optical power; The fifth lens with positive optical power has a convex object-side surface and a convex image-side surface. The sixth lens with negative optical power has a concave object side and a convex image side. The seventh lens, which has positive optical power, has a convex object-side surface; Among them, the true image height IH corresponding to the maximum field angle of the optical lens and the radian value θ of the maximum half-field angle of the optical lens satisfy: 28mm < (IH / 2) / θ < 35.5mm; the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -11 < f123 / f4567 < -3.2.

[0006] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.7 < TTL / f < 3.3; the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 1.8 < TTL / IH < 2.2.

[0007] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 30° < FOV / Fno < 40°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.8 < IH / EPD < 5.3.

[0008] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.35 < IH / f < 1.65; the overall optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.06 < 1°×TTL / (IH / 2) / (FOV / 2) < 0.09.

[0009] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 65° < f×FOV / IH < 75°; the half-aperture d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.35 < d1 / (IH / 2) / tan(FOV / 2) < 0.65.

[0010] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.6 < f1 / f < -1.9; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -1.6 < f2 / f < -0.8; the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 1.3 < f1 / f2 < 2.9.

[0011] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.8 < f3 / f < 1.2; the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -23 < f4 / f < -4.5; the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.85 < f5 / f < 1.4; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -10 < f6 / f < -1.2; the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.3 < f7 / f < 3.2; the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: 0.7 < R7 / R8 < 1.3.

[0012] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the combined focal length f123 of the first lens, the second lens, and the third lens and the effective focal length f of the optical lens satisfy: -13 < f123 / f < -3.9; the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens and the effective focal length f of the optical lens satisfy: 1 < f4567 / f < 1.35; the focal length f1 of the first lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: 0.15 < f1 / f123 < 0.6; the focal length f2 of the second lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: 0.1 < f2 / f123 < 0.3.

[0013] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: -3.4 < R1 / R2 < -1.1; 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: -3 < R3 / R4 < -1.2; the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.1 < (R1 + R2) / (R1 - R2) < 0.6; 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: 0.1 < (R3 + R4) / (R3 - R4) < 0.5.

[0014] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the true image height IH corresponding to the maximum field angle of the optical lens and the radian value θ of the maximum half field angle of the optical lens satisfy: 30.96 mm < (IH / 2) / θ < 32.59 mm; the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -10.24 < f123 / f4567 < -3.47; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -4.9 < R1 / f < -2.5; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 1.3 < R2 / f < 2.35; 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: -2.8 < R3 / f < -1.1; 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: 0.6 < R4 / f < 1.2.

[0015] The optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the reception quality of the lens, reduce aberration, improve the imaging quality of the lens, and enable the lens to have one or more advantages such as a large image plane, a large field angle, miniaturization, a small CRA, and high collimation performance. 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 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 2 is a F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 1 of the present invention.

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

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

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

[0021] Figure 6 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

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

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

[0024] Figure 9 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0025] Figure 10 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0026] Figure 11 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0027] Figure 12 This is a relative illumination curve of the optical lens in Embodiment 3 of the present invention.

[0028] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0029] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this 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.

[0030] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0031] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0032] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity 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 location of the concaveness 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 subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0033] It should also be understood that the terms "comprising," "including," "having," "containing," 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. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0034] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] The optical lens provided in this embodiment of the invention can be used as a receiving lens for lidar, transmitting light reflected from the surface of an object to the imaging plane. The optical lens of this invention has seven lenses with optical power, sequentially comprising, along the optical axis from the object side to the imaging plane: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0037] In some embodiments, the first lens may have a negative optical power, with its object side being concave and its image side being concave. The second lens may have a negative optical power, with its object side being concave and its image side being concave. The third lens may have a positive optical power, with its object side being convex and its image side being convex. The fourth lens may have a negative optical power, with its object side being either concave or convex and its image side being either concave or convex. The fifth lens may have a positive optical power, with its object side being convex and its image side being convex. The sixth lens may have a negative optical power, with its object side being concave and its image side being convex. The seventh lens may have a positive optical power, with its object side being convex and its image side being either concave or convex.

[0038] In some embodiments, the optical lens may further include an aperture, which may be located between the third lens and the fourth lens. It can be understood that the aperture is used to limit the amount of incident light to change the brightness of the imaging. When the aperture is located between the third lens and the fourth lens, it is convenient for correcting the aperture aberration.

[0039] In some embodiments, the optical lens may further include a filter, which is disposed between the seventh 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 the normal imaging.

[0040] In some embodiments, for the true image height IH corresponding to the maximum field angle of the optical lens and the radian value θ of the maximum half-field angle of the optical lens, it satisfies: 28mm < (IH / 2) / θ < 35.5mm. Meeting the above range realizes the large image plane characteristic and improves the imaging quality of the optical system. More specifically, 30.96mm < (IH / 2) / θ < 32.59mm.

[0041] In some embodiments, for the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens, it satisfies: -11 < f123 / f4567 < -3.2. Meeting the above range is beneficial to balancing the distortion and astigmatism generated by the front and rear lenses of the optical lens by reasonably setting the optical powers of the lens groups before and after the aperture, and improving the imaging quality of the optical lens. More specifically, -10.24 < f123 / f4567 < -3.47.

[0042] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.7 < TTL / f < 3.3; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 1.8 < TTL / IH < 2.2. Meeting the above ranges helps to balance the total length and volume of the optical lens by reasonably controlling the total length, focal length, and image height of the optical lens, which is beneficial to improving the structural stability of the optical lens. More specifically, 2.99 < TTL / f < 3.06; 1.99 < TTL / IH < 2.06.

[0043] In some embodiments, the maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 30° < FOV / Fno < 40°. Meeting the above conditions is beneficial to expanding the field angle of the lens and increasing the aperture of the lens, achieving the characteristics of a large aperture. More specifically, 33.32° < FOV / Fno < 37.87°.

[0044] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.8 < IH / EPD < 5.3. Meeting the above conditions makes the field of view and light flux balanced, improves the imaging quality of the lens, and can achieve high-quality collimation performance. More specifically, 4.15 < IH / EPD < 4.85.

[0045] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.35 < IH / f < 1.65. Meeting the above range can reasonably control the image height and focal length of the optical lens, provide a balance between the image height and focal length for the optical lens, and help to improve the imaging quality. More specifically, 1.46 < IH / f < 1.52.

[0046] In some embodiments, the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.06 < 1° × TTL / (IH / 2) / (FOV / 2) < 0.09. Meeting the above range helps to control the structural balance of the total length, field angle, and image height of the optical lens, making the structure of the optical lens more stable under the premise of meeting the design requirements.

[0047] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 65° < f × FOV / IH < 75°. Meeting the above range is conducive to achieving the balance between the large field angle and large target surface imaging of the optical lens by reasonably restricting the relationship among the focal length, field angle, and image height of the optical lens. More specifically, 67.94° < f × FOV / IH < 71.45°.

[0048] In some embodiments, the clear aperture radius d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.35 < d1 / (IH / 2) / tan(FOV / 2) < 0.65. Meeting the above range can reasonably control the front aperture while meeting the requirements of the optical lens having a large field angle and a large image height, which is conducive to the miniaturization of the optical lens. More specifically, 0.38 < d1 / (IH / 2) / tan(FOV / 2) < 0.61.

[0049] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.6 < f1 / f < -1.9. Meeting the above range can endow the first lens with a strong negative optical power, capture light rays with a large field angle, and is conducive to the optical lens having the characteristic of a large field angle. More specifically, -2.39 < f1 / f < -2.11.

[0050] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -1.6 < f2 / f < -0.8. Meeting the above range can endow the second lens with an appropriate negative optical power, further expand the field angle of the optical lens, and balance and share the negative optical power at the front end of the optical lens. More specifically, -1.43 < f2 / f < -0.89.

[0051] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 1.3 < f1 / f2 < 2.9. Meeting the above range can quickly collect and adjust the light path of the large field angle beam at the front end of the lens, so as to ensure that subsequent lenses such as the third lens have a smaller aperture, and at the same time realize the characteristics of the large field angle of the lens and the advantage of small volume. More specifically, 1.48 < f1 / f2 < 2.64.

[0052] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.8 < f3 / f < 1.2. The third lens is a positive lens, which transmits the light beam to the final imaging lens group, and compensates for the aberration with the front and rear lenses, so as to achieve high imaging quality of the lens and high-quality collimation performance. More specifically, 0.88 < f3 / f < 1.09.

[0053] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -23 < f4 / f < -4.5. Satisfying the above range helps the fourth lens to have an appropriate negative optical power and can appropriately reduce spherical aberration and coma. More specifically, -21.12 < f4 / f < -5.

[0054] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.85 < f5 / f < 1.4. Satisfying the above range helps the fifth lens to have an appropriate positive optical power and balance the field curvature and astigmatism of the optical lens. More specifically, 0.93 < f5 / f < 1.29.

[0055] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -10 < f6 / f < -1.2. Satisfying the above range helps the sixth lens to have an appropriate negative optical power, enables reasonable control of the smooth light trend at the rear end of the optical lens, and reduces aberration. More specifically, -9.07 < f6 / f < -1.32.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.3 < f7 / f < 3.2. Satisfying the above range enables the seventh lens to have an appropriate positive optical power, helps to reasonably control the angle of light entering the rear - end chip, and reduces the eccentricity sensitivity of the chip. More specifically, 1.47 < f7 / f < 2.94.

[0057] In some embodiments, 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: 0.7 < R7 / R8 < 1.3. Satisfying the above range and reasonably setting the surface shape of the fourth lens can make the light trend smoother. More specifically, 0.74 < R7 / R8 < 1.21.

[0058] In some embodiments, the combined focal length f123 of the first lens, the second lens, and the third lens and the effective focal length f of the optical lens satisfy: -13 < f123 / f < -3.9; the focal length f1 of the first lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: 0.15 < f1 / f123 < 0.6; the focal length f2 of the second lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: 0.1 < f2 / f123 < 0.3. Satisfying the above ranges enables the overall front end of the optical lens and each lens to have appropriate optical powers, and can enable large-angle light entering the lens to be fully transmitted to the rear light system, obtaining a larger field of view range and higher relative illumination. More specifically, -11.91 < f123 / f < -4.26; 0.17 < f1 / f123 < 0.57; 0.11 < f2 / f123 < 0.24.

[0059] In some embodiments, the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens and the effective focal length f of the optical lens satisfy: 1 < f4567 / f < 1.35. Satisfying the above range can make the overall rear end of the optical lens have a strong positive optical power, effectively transmit more light beams to the imaging surface, and can reduce the deviation of the incident angle and the exit angle of light in different fields of view. More specifically, 1.09 < f4567 / f < 1.24.

[0060] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: -3.4 < R1 / R2 < -1.1; the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.1 < (R1 + R2) / (R1 - R2) < 0.6; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -4.9 < R1 / f < -2.5; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 1.3 < R2 / f < 2.35. Satisfying the above ranges can reasonably set the surface shape of the first lens, enhance the light-gathering ability of the first lens, and thus achieve an ultra-large field of view angle. More specifically, -3.13 < R1 / R2 < -1.28; 0.12 < (R1 + R2) / (R1 - R2) < 0.52; -4.51 < R1 / f < -2.74; 1.43 < R2 / f < 2.15.

[0061] In some embodiments, 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: -3 < R3 / R4 < -1.2; 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: 0.1 < (R3 + R4) / (R3 - R4) < 0.5; 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: -2.8 < R3 / f < -1.1; 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: 0.6 < R4 / f < 1.2. Meeting the above ranges, the second lens has a suitable surface shape, which helps to control the incident angle and the exit angle of light entering and leaving the second lens, making the light trend gentle and reducing the difficulty of aberration correction for the rear-end lens. More specifically, -2.74 < R3 / R4 < -1.37; 0.15 < (R3 + R4) / (R3 - R4) < 0.47; -2.62 < R3 / f < -1.19; 0.7 < R4 / f < 1.12.

[0062] In some embodiments, the distance BL on the optical axis from the image side surface of the seventh lens to the imaging surface and the effective focal length f of the optical lens satisfy: 0.27 < BL / f < 0.72. Meeting the above range can endow the optical lens with the characteristic of long back focal length, meet the arrangement requirements of the rear-end chip, and reduce the assembly and processing difficulty.

[0063] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.25 mm / ° < IH / FOV < 0.3 mm / ° . Meeting the above range can ensure the field angle characteristic of the optical lens on the premise of meeting the image height requirement, so that the optical lens has good optical performance. More specifically, 0.26 mm / ° < IH / FOV < 0.29 mm / ° .

[0064] In some embodiments, the clear aperture radius d1 of the object side surface of the first lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.45 < d1 / (IH / 2) < 0.85. Meeting the above range can balance the small front aperture and the large image surface of the optical lens, which is beneficial to the miniaturization of the optical lens. More specifically, 0.46 < d1 / (IH / 2) < 0.81.

[0065] In some embodiments, the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -0.5 < (R11 - R12) / (R11 + R12) < -0.1. By satisfying the above range, the radii of curvature of the object side surface and the image side surface of the sixth lens are reasonably controlled, which is beneficial to controlling the shape of the sixth lens, correcting the aberration generated by itself, and improving the imaging quality. More specifically, -0.49 < (R11 - R12) / (R11 + R12) < -0.12.

[0066] In some embodiments, 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: -0.55 < (R5 + R6) / (R5 - R6) < -0.1. By satisfying the above range, the shapes of the object side surface and the image side surface of the third lens are reasonably defined, which can control the third lens to have an appropriate surface shape, help control the light trend in the marginal field of view, improve the imaging quality of the marginal field of view, and achieve high-quality collimation performance. More specifically, -0.5 < (R5 + R6) / (R5 - R6) < -0.14.

[0067] In some embodiments, the optical lens satisfies the conditional formula: 19 mm < f < 20 mm, 5.5 mm < EPD < 7.5 mm, 56 mm < TTL < 62 mm, 2.6 < Fno < 3.4, 3.6° < CRA < 7.5°, 5 mm < BL < 14 mm, 90° < FOV < 118°, 26 mm < IH < 32 mm; where f represents the effective focal length 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, CRA represents the chief ray incident angle at the maximum image height of the optical lens, BL represents the distance from the image side surface of the seventh lens to the imaging surface on the optical axis, FOV represents the maximum field angle of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. By satisfying the above conditions, it shows that the optical lens provided by the embodiments of the present invention has at least one or more advantages such as a large image plane, a large field angle, miniaturization, and a small CRA. More specifically, 19.3 mm < f < 19.33 mm, 6.02 mm < EPD < 6.91 mm, 57.9 mm < TTL < 59.1 mm, 2.79 < Fno < 3.21, 3.8° < CRA < 7.2°, 5.46 mm < BL < 13.75 mm, 99° < FOV < 109°, 28.42 mm < IH < 29.2 mm.

[0068] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens is made of plastic, production costs can be effectively reduced. Conversely, when the lens is made of glass, the low dispersion characteristic of glass itself can effectively correct the geometric chromatic aberration of the optical system. The lens provided by the present invention can employ an all-glass lens structure, which can reduce dispersion, effectively correct chromatic aberration of the optical lens, and improve image quality.

[0069] In some embodiments, the first, second, third, fourth, fifth, sixth, and seventh lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, the first, second, third, fourth, fifth, sixth, and seventh lenses of this invention are all spherical lenses.

[0070] The present invention will be further described below with reference to several 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 tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention. Example 1

[0071] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0072] The first lens L1 has negative optical power, its object side S1 is concave, and its image side S2 is concave. The second lens L2 has negative optical power, its object side S3 is concave, and its image side S4 is concave. The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex. The fourth lens L4 has negative optical power, its object side S7 is concave, and its image side S8 is convex. The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side S10 is convex. The sixth lens L6 has negative optical power, its object side S11 is concave, and its image side S12 is convex. The seventh lens L7 has positive optical power, its object side surface S13 is convex, and its image side surface S14 is concave. The object-side surface S15 and the image-side surface S16 of filter G1 are both planar. The object side S17 and image side S18 of the protective glass G2 are both flat. The imaging plane S19 is a plane.

[0073] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are 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 In this embodiment, the F-Tan (Theta) distortion curve, MTF curve, and relative illumination curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 As shown.

[0076] Figure 2 The F-Tan (Theta) distortion curve for Example 1 is shown, representing the F-Tan (Theta) distortion of light at different image heights on the imaging plane. The horizontal axis represents the F-Tan (Theta) distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tan (Theta) distortion of the optical lens is controlled within -40% to 0, indicating that the optical lens can effectively correct distortion.

[0077] Figure 3 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation 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. As can be seen from the figure, the MTF value of this example is above 0.88 throughout the entire field of view. Within the range of 0 to 10 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating good imaging quality.

[0078] Figure 4The relative illumination curves for Example 1 are shown, representing the relative illumination values ​​at different field-of-view angles on the imaging plane. The horizontal axis represents the half-field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 88% at the maximum half-field angle, indicating that the optical lens has good relative illumination. Example 2

[0079] Please see Figure 5 The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The difference between this embodiment and Embodiment 1 is that: the object side S7 of the fourth lens L4 is a convex surface; the image side S8 of the fourth lens L4 is a concave surface; the image side S14 of the seventh lens L7 is a convex surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0080] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2.

[0081] Table 2 In this embodiment, the F-Tan (Theta) distortion curve, MTF curve, and relative illumination curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0082] from Figure 6 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -45% to 0, indicating that the optical lens can effectively correct distortion.

[0083] from Figure 7 As can be seen, the MTF value of this embodiment is above 0.8 throughout the entire field of view. Within the range of 0 to 10 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating good imaging quality.

[0084] from Figure 8 As can be seen, the relative illumination value of the optical lens is still greater than 80% at the maximum half field of view, indicating that the optical lens has good relative illumination. Example 3

[0085] Please see Figure 9 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The difference between this embodiment and Embodiment 1 is that the image side surface S14 of the seventh lens L7 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0086] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3.

[0087] Table 3 In this embodiment, the F-Tan (Theta) distortion curve, MTF curve, and relative illumination curve of the optical lens 300 are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown.

[0088] from Figure 10 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -45% to 0, indicating that the optical lens can effectively correct distortion.

[0089] from Figure 11 As can be seen, the MTF value of this embodiment is above 0.8 throughout the entire field of view. Within the range of 0 to 10 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating good imaging quality.

[0090] from Figure 12 As can be seen, the relative illumination value of the optical lens is still greater than 98% at the maximum half field of view, indicating that the optical lens has good relative illumination.

[0091] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, distance BL from the image side of the seventh lens to the imaging plane on the optical axis, and the numerical values ​​corresponding to each conditional expression in each embodiment.

[0092] Table 4 In summary, the optical lens provided by the present invention employs seven lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the receiving quality of the lens, reduce aberrations, and enhance the imaging quality of the lens, giving the lens one or more advantages such as a large image plane, a large field of view, miniaturization, small CRA, and high collimation performance.

[0093] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens comprising seven lenses having optical power, 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 concave and whose image side is concave; A second lens with a negative optical power, whose object side is concave and whose image side is concave; A third lens with a positive optical power, whose object side is convex and whose image side is convex; A fourth lens with a negative optical power; A fifth lens with a positive optical power, whose object side is convex and whose image side is convex; A sixth lens with a negative optical power, whose object side is concave and whose image side is convex; A seventh lens with a positive optical power, whose object side is convex; Wherein, the true image height IH corresponding to the maximum field angle of the optical lens and the radian value θ of the maximum half-field angle of the optical lens satisfy: 28mm < (IH / 2) / θ < 35.5mm; The combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -11 < f123 / f4567 < -3.

2.

2. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.7 < TTL / f < 3.3; The overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 1.8 < TTL / IH < 2.

2.

3. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 30° < FOV / Fno < 40°; The true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.8 < IH / EPD < 5.

3.

4. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.35 < IH / f < 1.65; The overall optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.06 < 1°×TTL / (IH / 2) / (FOV / 2) < 0.

09.

5. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The effective focal length f of the optical lens, the maximum field angle FOV of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 65° < f×FOV / IH < 75°; The clear aperture radius d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.35 < d1 / (IH / 2) / tan(FOV / 2) < 0.

65.

6. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.6 < f1 / f < -1.9; The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -1.6 < f2 / f < -0.8; The focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 1.3 < f1 / f2 < 2.

9.

7. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.8 < f3 / f < 1.2; The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -23 < f4 / f < -4.5; The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.85 < f5 / f < 1.4; The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -10 < f6 / f < -1.2; The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.3 < f7 / f < 3.2; The radius of curvature R7 of the object side of the fourth lens and the radius of curvature R8 of the image side of the fourth lens satisfy: 0.7 < R7 / R8 < 1.

3.

8. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The combined focal length f123 of the first lens, the second lens, and the third lens and the effective focal length f of the optical lens satisfy: -13 < f123 / f < -3.9; The combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens and the effective focal length f of the optical lens satisfy: 1 < f4567 / f < 1.35; The focal length f1 of the first lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: 0.15 < f1 / f123 < 0.6; The focal length f2 of the second lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: 0.1 < f2 / f123 < 0.

3.

9. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: -3.4 < R1 / R2 < -1.1; The radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: -3 < R3 / R4 < -1.2; The radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: 0.1 < (R1 + R2) / (R1 - R2) < 0.6; The radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: 0.1 < (R3 + R4) / (R3 - R4) < 0.

5.

10. The optical lens according to any one of claims 1-9, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The true image height IH corresponding to the maximum field angle of the optical lens and the radian value θ of the maximum half-field angle of the optical lens satisfy: 30.96 mm < (IH / 2) / θ < 32.59 mm; The combined focal length f123 of the first lens, the second lens, and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: -10.24 < f123 / f4567 < -3.47; The object-side curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: -4.9 < R1 / f < -2.5; The image-side curvature radius R2 of the first lens and the effective focal length f of the optical lens satisfy: 1.3 < R2 / f < 2.35; The object-side curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: -2.8 < R3 / f < -1.1; The image-side curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < R4 / f < 1.2.

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