Optical lens

Abstract

The application discloses an optical lens, which comprises six lenses in sequence along an optical axis from an object side to an imaging surface, and comprises the following: a first lens with negative optical power, wherein the object side surface is a concave surface and the image side surface is a convex surface; a second lens with positive optical power, wherein the image side surface is a convex surface; a third lens with positive optical power, wherein the image side surface is a convex surface; a fourth lens with optical power, wherein the object side surface is a concave surface and the image side surface is a convex surface; a fifth lens with negative optical power, wherein the image side surface is a concave surface; and a sixth lens with positive optical power. The application adopts six lenses, and has the advantages of long focal length, miniaturization, low cost, high resolution, normal use in weak light and harsh environment and at least one of the advantages.

Description

Technical Field

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

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] In automotive cameras, the forward-facing camera is a core component of ADAS (Advanced Driver Assistance Systems), primarily responsible for functions such as forward collision warning, lane departure warning, and pedestrian detection. Currently, due to the complex algorithms and chip processing involved, forward-facing cameras are typically much more expensive than other types of cameras, reflecting their crucial role in automotive camera systems. With the rapid development of advanced driver assistance systems, the requirements for forward-facing lenses are also increasing. Therefore, there is a need to develop an optical lens with high imaging quality. Summary of the Invention

[0004] Therefore, the purpose of this invention is to provide an optical lens that has the advantages of at least one of the following: long focal length, miniaturization, low cost, high resolution, and normal use in low light and harsh environments.

[0005] This invention provides an optical lens comprising six lenses, arranged sequentially along the optical axis from the object side to the image plane: a first lens with negative optical power, the object side of which is concave and the image side of which is convex; a second lens with positive optical power, the image side of which is convex; a third lens with positive optical power, the image side of which is convex; a fourth lens with optical power, the object side of which is concave and the image side of which is convex; a fifth lens with negative optical power, the image side of which is concave; and a sixth lens with positive optical power.

[0006] In some embodiments, the radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side satisfy: -0.65 < (R1-R2) / (R1+R2) < -0.1.

[0007] In some implementations, the radius of curvature R7 of the object side of the fourth lens and the radius of curvature R8 of the image side satisfy: |(R7-R8) / (R7+R8)|<0.75.

[0008] In some implementations, the total optical length (TTL) of the optical lens and the effective focal length (f) of the optical lens satisfy the condition: 1.8 < TTL / f < 2.5.

[0009] In some implementations, the image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 0.95 < (IH / 2) / (f×Tan(FOV / 2)) < 1.1.

[0010] In some implementations, the total optical length TTL of the optical lens, the image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 55 < 180° × TTL / (IH / 2) / (FOV / 2) < 80°.

[0011] In some implementations, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < -1.5.

[0012] In some implementations, the effective focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1.5 < |f4 / f|.

[0013] In some implementations, the radius of curvature R4 of the image side of the second lens satisfies the condition R4 / f < -0.5 with respect to the effective focal length f of the optical lens.

[0014] In some implementations, the radius of curvature R10 of the image side of the fifth lens satisfies the condition that 0.2 < R10 / f with respect to the effective focal length f of the optical lens.

[0015] Compared to existing technologies, the optical lens provided by this invention employs six lenses with optical power. Through specific surface shape settings and reasonable optical power distribution, it possesses advantages such as long focal length, miniaturization, low cost, high resolution, and normal operation in low light and harsh environments. In particular, the object-side surface of the first lens is concave, which diverges light, allowing subsequent lenses to have a larger light-receiving surface. The image-side surface is convex, converging light and facilitating control of the aperture of subsequent lenses, enabling miniaturization. The object-side surface of the fourth lens is concave, smoothly receiving light and allowing light emitted from the third lens to enter the rear optical system smoothly, reducing aberrations and improving image quality. The image-side surface is convex, causing edge field rays to bend towards the optical axis after passing through the second side of the fourth lens, which helps reduce the rear aperture of the system. The fourth lens has a meniscus shape, with minimal difference in surface changes with temperature, contributing to better thermal stability at high temperatures. Therefore, this optical lens better meets the requirements of automotive lenses. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0017] Figure 1This is a schematic diagram of the structure of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 2 This is a field curvature curve diagram of the optical lens of Embodiment 1 of the present invention.

[0019] Figure 3 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 4 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 5 This is a schematic diagram of the optical lens structure of Embodiment 2 of the present invention.

[0022] Figure 6 This is a field curvature curve diagram of the optical lens of Embodiment 2 of the present invention.

[0023] Figure 7 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 8 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 9 This is a schematic diagram of the optical lens structure of Embodiment 3 of the present invention.

[0026] Figure 10 This is a field curvature curve diagram of the optical lens of Embodiment 3 of the present invention.

[0027] Figure 11 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0028] Figure 12 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 13 This is a schematic diagram of the optical lens structure of Embodiment 4 of the present invention.

[0030] Figure 14 This is a field curvature curve diagram of the optical lens of Embodiment 4 of the present invention.

[0031] Figure 15 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 4 of the present invention.

[0032] Figure 16 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0033] Figure 17This is a schematic diagram of the structure of the optical lens in Embodiment 5 of the present invention.

[0034] Figure 18 This is a field curvature curve diagram of the optical lens of Embodiment 5 of the present invention.

[0035] Figure 19 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 5 of the present invention.

[0036] Figure 20 This is the MTF curve of the optical lens in Embodiment 5 of the present invention.

[0037] Figure 21 This is a schematic diagram of the optical lens structure of Embodiment 6 of the present invention.

[0038] Figure 22 This is a field curvature curve diagram of the optical lens of Embodiment 6 of the present invention.

[0039] Figure 23 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 6 of the present invention.

[0040] Figure 24 This is the MTF curve of the optical lens in Embodiment 6 of the present invention. Detailed Implementation

[0041] To better understand the invention, various aspects of the invention 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 the invention and are not intended to limit the scope of the invention 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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 the invention, the word "may" is used to mean "one or more embodiments of the invention." And the term "exemplary" is intended to refer to an example or illustration.

[0046] 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 invention 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 defined herein.

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] This invention proposes an optical lens with a total of six lenses. The optical lens includes, 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, and a sixth lens, and the optical centers of each lens are located on the same straight line.

[0049] In some embodiments, the first lens is configured to have negative optical power, which is beneficial for diverging light. Under the same field of view, the light emitted from the image side of the first lens can provide a larger light receiving surface for the subsequent optical system, reducing the front aperture. The object side is concave, which also serves to diverge light. The light emitted from the object side of the first lens can provide a larger light receiving surface for the subsequent lenses. The image side is convex, which has a converging effect on light, which is beneficial for controlling the aperture of the rear lenses and achieving miniaturization.

[0050] In some embodiments, the second lens is configured to have positive optical power, which is beneficial for converging light. When paired with the first lens, which has negative optical power, it can reduce the overall length of the optical lens, and the converging effect on the light can further reduce the rear aperture. The image side is convex, which can converge the light passing through the first lens and reduce the light height. This reduces the aperture of the optical lens while slowing down the light turning trend to make it transition smoothly. At the same time, it can balance various aberrations generated by the front lens and improve the overall imaging quality of the optical lens.

[0051] In some embodiments, the third lens is configured to have positive optical power, which is beneficial for receiving the light rays converged from the second lens, reducing the height of the beam incident on the object side of the fourth lens, and reducing the aperture of the object side of the fourth lens; the image side is convex, which can smoothly receive the light rays, allowing the light rays emitted from the second lens to smoothly enter the rear optical system, reducing the generation of aberrations, improving image quality, and causing the edge field rays to be deflected in the direction of the optical axis after passing the second side of the third lens, which is beneficial for reducing the rear port aperture of the system.

[0052] In some implementations, the fourth lens is configured to have optical power, which is beneficial for converging light. When paired with the fifth lens, it can effectively correct the aberrations of the optical lens, improve image quality, and optimize optical performance such as distortion. The object side is concave and the image side is convex, which can suppress the angle of the edge field of view incident on the imaging surface, effectively transmit more light beams to the imaging surface, and improve image quality.

[0053] In some embodiments, the fifth lens is configured to have negative optical power, which is beneficial for diverging light and provides a larger light-receiving surface for the subsequent optical system. This improves optical performance and can effectively correct various aberrations caused by the front lens, thereby enhancing the image quality of the optical lens. The image side is concave, which allows for adjustment of the light rays passing through the central and peripheral fields of view of the fifth lens. In particular, it adjusts the angle at which the peripheral field of view rays are incident on the imaging surface so that the main rays exit parallel to the imaging surface. This increases the proportion of the peripheral field of view in the image and enhances the image clarity of the peripheral field of view. At the same time, it can correct various aberrations caused by the front lens and improve the overall image quality of the optical lens.

[0054] In some implementations, the sixth lens is configured to have positive optical power, which is beneficial for receiving the light from the front end and improving resolution. Furthermore, the fifth lens receives the light compressed by the front positive lens, reduces the light angle, meets the requirements of CRA, and can optimize spherical aberration and improve image quality.

[0055] In some embodiments, the aperture stop can be positioned between the first lens and the second lens. It is understood that the aperture stop can be used to limit the amount of light entering the lens, thereby changing the brightness of the image. Furthermore, when the aperture stop is located between the first and second lenses, it can rationally allocate the functions of the first to sixth lenses. For example, the first lens can be used to receive light to a greater extent, while the second to sixth lenses can be used to correct aberrations, which is beneficial for balancing the structure of the entire optical system. In addition, when the aperture stop is located between the first and second lenses, it facilitates the correction of aperture aberrations and the balancing of the structure and focal length allocation of the front and rear lens groups.

[0056] In some embodiments, the optical lens may further include a filter disposed between the sixth lens and the imaging surface to filter out interference light and prevent interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0057] In some implementations, the effective focal length f of the optical lens satisfies: 12mm < f < 17mm. Meeting this range helps the optical lens to have telephoto characteristics, ensuring the telephoto effect of the optical lens, giving the system a large magnification, and providing good image quality for objects in a longer field of view.

[0058] In some implementations, the maximum field of view of the optical lens satisfies the following condition: 30° < FOV < 40°. Meeting this range helps the optical lens to have a suitable field of view, enabling clear imaging of distant targets.

[0059] In some implementations, the aperture value FNO of the optical lens satisfies the following condition: 1.4 < FNO < 1.8. Meeting this range is beneficial for achieving large aperture characteristics, ensuring image clarity even in low-light environments or at night.

[0060] In some implementations, the angle of incidence (CRA) of the principal ray at the maximum field of view of the optical lens on the image plane satisfies: 14° < CRA < 21°. Satisfying this range allows for a larger tolerance range between the CRA of the optical lens and the CRA of the image sensor, improving the adaptability of the optical lens to the image sensor.

[0061] In some implementations, the total optical length (TTL) of the optical lens and the effective focal length (f) of the optical lens satisfy the condition: 1.8 < TTL / f < 2.5. Meeting this range effectively compresses the total length, ensuring sufficient space to adjust the lens structure and optimize the imaging effect of the optical lens.

[0062] In some embodiments, the image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the maximum field of view FOV of the optical lens satisfy the following condition: 0.95 < (IH / 2) / (f × Tan(FOV / 2)) < 1.1. Meeting this range allows for better control of the optical lens distortion, resulting in low distortion characteristics, and also improves the resolution of the optical lens.

[0063] In some implementations, the 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 the following condition: 0.58 < IH / f < 0.7. Meeting this range ensures that the chip with a large image sensor is matched, so that the optical lens has both telephoto and large image sensor characteristics.

[0064] In some implementations, the optical back focal length (BFL) of the optical lens and the effective focal length (f) of the optical lens satisfy the condition: 0.2 < BFL / f < 0.45. Meeting this range achieves a balance between good image quality and an easy-to-assemble optical back focal length, which helps ensure the image quality of the optical lens while avoiding interference between the lens and other components, reducing the difficulty of camera module assembly, and improving production yield.

[0065] In some embodiments, the total optical length (TTL) of the optical lens, the image height (IH) corresponding to the maximum field of view (FOV) of the optical lens, and the maximum field of view (FOV) of the optical lens satisfy the following condition: 55 < 180° × TTL / (IH / 2) / (FOV / 2) < 80°. Meeting this range allows for limiting the length of the optical lens while maintaining the same imaging area and field of view, thus achieving miniaturization of the optical lens.

[0066] In some embodiments, the total optical length TTL of the optical lens and the sum of the center thicknesses ∑CT of the first to sixth lenses along the optical axis satisfy the condition: 0.4 < ∑CT / TTL < 0.8. Satisfying this range allows for a reduction in the total length of the optical lens, resulting in a more compact structure.

[0067] In some embodiments, the half-aperture d1 of the first lens object side, the image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 3.3 < d1 / (IH / 2) / Tan(FOV / 2) < 4.7. Satisfying the above range allows for a small front aperture while ensuring the optical lens has a suitable field of view and image height, which is beneficial for the miniaturization of the optical lens.

[0068] In some embodiments, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < -1.5. Satisfying this range allows a wider range of light to enter the optical lens, obtaining more image information, and also helps control lens distortion and reduce field curvature, improving the geometric accuracy of the imaging plane. Preferably, -6 < f1 / f < -1.5.

[0069] In some embodiments, the effective focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.1 < f2 / f. Meeting this range allows for the convergence of light rays while reducing the light refraction angle, resulting in a smoother transition of light path. It also balances various aberrations generated by the front lens, improving the imaging quality of the optical lens. Preferably, 1.1 < f2 / f < 2.

[0070] In some implementations, the effective focal length f3 of the third lens and the effective focal length f of the optical lens satisfy the condition: 0.9 < f3 / f < 2.2. Meeting this range can reduce the light deflection angle to ensure a smooth transition of light path, while also balancing various aberrations generated by the front lens and improving the imaging quality of the optical lens.

[0071] In some embodiments, the effective focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1.5 < |f4 / f|. Meeting this range allows for the convergence and adjustment of light rays emanating from the fourth lens, reducing the tendency of light rays to bend and the degree of convergence, resulting in a smoother light transition. Simultaneously, it can balance various aberrations generated by the front lens, improving the overall imaging quality of the optical lens. Preferably, 1.5 < |f4 / f| < 6.

[0072] In some embodiments, the effective focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy the condition: -1.5 < f5 / f < -0.3. Satisfying this range can increase the imaging area, and the combination of the fourth and fifth lenses can optimize lens chromatic aberration and improve image quality.

[0073] In some embodiments, the effective focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.9 < f6 / f. Meeting this range optimizes spherical aberration, improves image quality, and suppresses the angle of incidence on the imaging plane from the edge of the field of view, effectively transmitting more light beams to the imaging plane and further enhancing image quality. Preferably, 0.9 < f6 / f < 8.2.

[0074] In some embodiments, the radius of curvature R4 of the image-side surface of the second lens satisfies the condition R4 / f < -0.5 with the effective focal length f of the optical lens. Meeting this range allows the convex surface to face the image side, converging light rays from the edge of the field of view and improving the image quality of the edge field of view. Preferably, -2.5 < R4 / f < -0.5.

[0075] In some embodiments, the radius of curvature R6 of the image-side surface of the third lens satisfies the condition R6 / f < -0.5 with the effective focal length f of the optical lens. Meeting this range allows the convex surface to face the image side, converging light rays from the edge of the field of view and improving the image quality of the edge field of view. Preferably, -1.3 < R6 / f < -0.5.

[0076] In some embodiments, the radius of curvature R10 of the image-side surface of the fifth lens satisfies the condition 0.2 < R10 / f with the effective focal length f of the optical lens. Meeting this range allows the concave surface to face the image side, converging edge field-of-view rays and improving the relative illumination of the optical lens. Preferably, 0.2 < R10 / f < 1.7.

[0077] In some embodiments, the radius of curvature R1 of the object side and the radius of curvature R2 of the image side of the first lens satisfy: -0.65 < (R1-R2) / (R1+R2) < -0.15. Satisfying this range facilitates a smooth transition of light to the rear, collects more light into the lens, and improves resolving power while achieving a small aperture and short overall length.

[0078] In some embodiments, the radius of curvature R7 of the object side of the fourth lens and the radius of curvature R8 of the image side satisfy: |(R7-R8) / (R7+R8)| < 0.75. Satisfying this range helps to reduce field curvature and reduces the difficulty of field curvature correction for subsequent lenses, thereby improving image quality.

[0079] In some embodiments, 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 the following condition: -1 < R1 / f < -0.6. Meeting this range allows the concave surface to face the object side, thus diverging light rays. Light rays passing through the object-side surface of the first lens can provide subsequent lenses with a larger light-receiving surface.

[0080] In some embodiments, the radius of curvature R2 of the image-side surface of the first lens satisfies the following condition with respect to the effective focal length f of the optical lens: -4 < R2 / f < -1. Meeting this range allows the convex surface to face the image side, converging light rays and facilitating control of the aperture of the rear lens, thus enabling miniaturization.

[0081] In some embodiments, the radius of curvature R7 of the object-side surface of the fourth lens and the effective focal length f of the optical lens satisfy: R7 / f < -0.9. Meeting this range allows the concave surface to face the object side, smoothly receiving light rays and ensuring that the light rays emitted from the third lens enter the rear optical system smoothly, reducing aberrations and improving image quality. Preferably, -7.9 < R5 / f < -0.9.

[0082] In some embodiments, the radius of curvature R8 of the image-side surface of the fourth lens satisfies the condition -1.9 < R8 / f < -0.7 with the effective focal length f of the optical lens. Satisfying this range allows the convex surface to face the image side, causing the edge field rays to bend towards the optical axis after passing through the second side surface of the fourth lens, which helps to reduce the rear port diameter of the system.

[0083] In one implementation, the first, second, third, fourth, fifth, and sixth lenses can be made entirely of glass or a combination of glass and plastic, both of which achieve good imaging results. In this application, to improve the image quality of the lens, all lenses are made of glass. Furthermore, at least one of the object-side or image-side surfaces of the second and sixth lenses is aspherical. Aspherical lenses are characterized by a continuously changing curvature from the lens center to the lens periphery. Unlike spherical lenses, which have a constant curvature from the lens center to the lens periphery, aspherical lenses have better curvature radius characteristics, offering advantages in improving distortion aberrations and astigmatism.

[0084] To achieve better optical performance, the lens employs multiple aspherical lenses, and the shapes of each aspherical surface of the optical lens satisfy the following equation:

[0085]

[0086] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and A, B, C, D, E, and F are the second, fourth, sixth, eighth, tenth, and twelfth order surface coefficients, respectively.

[0087] 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.

[0088] Example 1

[0089] Please see Figure 1 The diagram shown is a schematic diagram of the structure of the optical lens provided in Embodiment 1 of the present invention. The optical lens includes, along the optical axis from the object side to the imaging plane S15, the following components in sequence: a first lens L1, an aperture ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter G1.

[0090] Among them, the first lens L1 is a spherical lens with negative optical power, the object-side surface S1 of the first lens is concave, and the image-side surface S2 of the first lens is convex; the second lens L2 is an aspherical lens with positive optical power, the object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is convex; the third lens L3 is a spherical lens with positive optical power, the object-side surface S5 of the third lens is concave, and the image-side surface S6 of the third lens is convex; the fourth lens L4 is a spherical lens with positive optical power. The fourth lens is a spherical lens with negative optical power. Its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens L5 is a spherical lens with negative optical power. Its object-side surface S9 is concave, and its image-side surface S10 is concave. The sixth lens L6 is an aspherical lens with positive optical power. Its object-side surface S11 is convex, and its image-side surface S12 is concave. The object-side surface S13 and image-side surface S14 of the filter G1 are both planar.

[0091] Specifically, the design parameters of each lens in the optical lens provided in this embodiment are shown in Table 1-1.

[0092] Table 1-1

[0093]

[0094] The surface shape coefficients of each aspherical surface of the optical lens in this embodiment are shown in Table 1-2.

[0095] Table 1-2

[0096]

[0097]

[0098] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.05 mm to 0.2 mm, indicating that the optical lens can effectively correct the field curvature.

[0099] Figure 3 The distortion curve of Example 1 is shown, which represents the F-Tan (Theta) distortion at different field-of-view angles on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the distortion value is controlled within the range of -1.2% to 0, indicating that the optical lens has small distortion, the image compression in the edge angle area is relatively smooth, and the sharpness of the unfolded image is effectively improved.

[0100] Figure 4The modulation transfer function (MTF) 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 0.2 throughout the entire field of view. Within the range of 0–120 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0101] Example 2

[0102] Please see Figure 5 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 2 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1 above, except that the curvature radius of each lens surface, the thickness of each lens, the aspherical coefficient of each lens and other parameters are different.

[0103] Specifically, the design parameters of each lens in the optical lens provided in this embodiment are shown in Table 2-1.

[0104] Table 2-1

[0105]

[0106]

[0107] The surface shape coefficients of each aspherical surface of the optical lens in this embodiment are shown in Table 2-2.

[0108] Table 2-2

[0109] Face number K A B C S3 3.95E+01 0.00E+00 0.00E+00 -2.17E-05 S4 -3.18E+00 0.00E+00 0.00E+00 -1.40E-05 S11 -6.79E+00 0.00E+00 4.65E-04 1.74E-04 S12 -8.21E-01 0.00E+00 1.95E-03 6.15E-05 Face number D E F S3 1.64E-06 -3.77E-08 4.34E-10 S4 1.21E-06 -2.84E-08 4.01E-10 S11 -1.25E-05 3.72E-07 -5.33E-09 S12 -4.51E-06 5.69E-08 -1.51E-09

[0110] Figures 6 to 8 The field curvature curve, distortion curve, and modulation transfer function (MTF) curve of Example 2 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within 0.05mm to 0.2mm, indicating that the optical lens can effectively correct field curvature; the distortion value is controlled within the range of 0% to 9%, indicating that the optical lens has low distortion; the MTF value of the optical lens is above 0.2 throughout the entire field of view, and within the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0111] Example 3

[0112] Please see Figure 9The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 3 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1 above, except that the curvature radius of each lens surface, the thickness of each lens, the aspherical coefficient of each lens and other parameters are different.

[0113] Specifically, the design parameters of each lens in the optical lens provided in this embodiment are shown in Table 3-1.

[0114] Table 3-1

[0115]

[0116]

[0117] The surface shape coefficients of each aspherical surface of the optical lens in this embodiment are shown in Table 3-2.

[0118] Table 3-2

[0119] Face number K A B C S3 5.17E+01 0.00E+00 0.00E+00 -1.15E-05 S4 -1.81E+00 0.00E+00 0.00E+00 -2.85E-06 S11 -2.52E-01 0.00E+00 9.37E-04 1.67E-04 S12 -4.98E-01 0.00E+00 1.38E-03 1.06E-04 Face number D E F S3 8.60E-07 -2.07E-08 2.25E-10 S4 2.45E-07 -4.27E-09 4.64E-11 S11 -1.19E-05 3.93E-07 -5.54E-09 S12 -5.04E-06 8.99E-08 -2.75E-10

[0120] Figures 10 to 12 The field curvature curve, distortion curve, and modulation transfer function (MTF) curve of Example 3 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within 0.05mm to 0.2mm, indicating that the optical lens can effectively correct field curvature; the distortion value is controlled within the range of 0% to 6%, indicating that the optical lens has low distortion; the MTF value of the optical lens is above 0.25 throughout the entire field of view, and within the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0121] Example 4

[0122] Please see Figure 13 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 4 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1 above, except that the fourth lens has negative optical power, and the curvature radius of each lens surface, the thickness of each lens, the aspherical coefficient of each lens and other parameters are different.

[0123] Specifically, the design parameters of each lens in the optical lens provided in this embodiment are shown in Table 4-1.

[0124] Table 4-1

[0125]

[0126] The surface shape coefficients of each aspherical surface of the optical lens in this embodiment are shown in Table 4-2.

[0127] Table 4-2

[0128] Face number K A B C S3 -2.08E+00 0.00E+00 0.00E+00 -1.82E-06 S4 3.89E+00 0.00E+00 0.00E+00 -3.59E-07 S11 -5.52E+00 0.00E+00 7.76E-04 -3.20E-05 S12 -4.62E-01 0.00E+00 -1.74E-04 -2.49E-06 Face number D E F S3 7.25E-08 -1.45E-09 9.95E-12 S4 2.43E-08 -4.83E-10 3.13E-12 S11 6.82E-07 -1.71E-08 1.64E-10 S12 -1.05E-06 3.78E-08 -4.07E-10

[0129] Figures 14 to 16 The field curvature curve, distortion curve, and modulation transfer function (MTF) curve of Example 4 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within 0–0.05 mm, indicating that the optical lens can effectively correct field curvature; the distortion value is controlled within the range of -0.4% to 0.5%, indicating that the optical lens has low distortion; the MTF value of the optical lens is above 0.55 throughout the entire field of view, and within the range of 0–120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0130] Example 5

[0131] Please see Figure 17 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 5 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1 above, except that the curvature radius of each lens surface, the thickness of each lens, the aspherical coefficient of each lens and other parameters are different.

[0132] Specifically, the design parameters of each lens in the optical lens provided in this embodiment are shown in Table 5-1.

[0133] Table 5-1

[0134]

[0135] The surface shape coefficients of each aspherical surface of the optical lens in this embodiment are shown in Table 5-2.

[0136] Table 5-2

[0137] Face number K A B C S3 5.01E+01 0.00E+00 0.00E+00 -9.35E-06 S4 -2.21E+00 0.00E+00 0.00E+00 -1.03E-06 S11 -8.06E+01 0.00E+00 1.12E-03 6.83E-05 S12 -3.61E-01 0.00E+00 1.71E-03 2.57E-05 Face number D E F S3 6.89E-07 -1.68E-08 1.68E-10 S4 1.54E-07 -2.66E-09 2.83E-11 S11 -4.92E-06 1.65E-07 -2.23E-09 S12 -2.15E-06 3.77E-08 -6.43E-10

[0138] Figures 18 to 20 The field curvature curve, distortion curve, and modulation transfer function (MTF) curve of Example 5 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within 0.05 mm to 0.2 mm, indicating that the optical lens can effectively correct field curvature; the distortion value is controlled within the range of 0 to 5%, indicating that the optical lens has low distortion; the MTF value of the optical lens is above 0.25 throughout the entire field of view, and within the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0139] Example 6

[0140] Please see Figure 21 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 6 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1 above, except that the curvature radius of each lens surface, the thickness of each lens, the aspherical coefficient of each lens and other parameters are different.

[0141] Specifically, the design parameters of each lens in the optical lens provided in this embodiment are shown in Table 6-1.

[0142] Table 6-1

[0143]

[0144] The surface shape coefficients of each aspherical surface of the optical lens in this embodiment are shown in Table 6-2.

[0145] Table 6-2

[0146] Face number K A B C S3 5.02E+01 0.00E+00 0.00E+00 -9.80E-06 S4 -1.66E+00 0.00E+00 0.00E+00 -1.27E-06 S11 3.44E+00 0.00E+00 1.20E-03 4.76E-06 S12 2.51E+01 0.00E+00 1.39E-03 -2.23E-05 Face number D E F S3 6.73E-07 -1.67E-08 1.72E-10 S4 9.45E-08 -1.50E-09 1.46E-11 S11 -2.03E-07 2.40E-09 1.62E-10 S12 2.29E-06 -1.15E-07 2.00E-09

[0147] Figures 22 to 24 The field curvature curve, distortion curve, and modulation transfer function (MTF) curve of Example 6 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within -0.1 mm to 0.1 mm, indicating that the optical lens can effectively correct field curvature; the distortion value is controlled within the range of -0.5% to 0.5%, indicating that the optical lens has low distortion; the MTF value of the optical lens is above 0.2 throughout the entire field of view, and within the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0148] Please refer to Table 7, which shows the optical characteristics of the optical lenses provided in the above six embodiments, including the effective focal length f, maximum field of view FOV, pupil diameter EPD, total optical length TTL, aperture value FNO, image height IH corresponding to the maximum field of view, principal ray incident angle CRA, optical back focal length BFL, and the values ​​corresponding to each conditional expression in each embodiment.

[0149] Table 7

[0150]

[0151]

[0152] In summary, the optical lens in this embodiment of the invention employs six lenses with optical power. By rationally allocating the optical power of each lens, rationally matching the surface shape of each lens, rationally setting the thickness of each lens and the spacing between each lens, rationally setting the position of the aperture, and setting the optical lens to have small distortion, a balance of telephoto (maximum f-number of 15.20mm), large aperture (minimum f-number of 1.60), and high pixel count can be achieved, thereby meeting the usage requirements of automotive lenses.

[0153] 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.

[0154] 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 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 the present invention should be determined by the appended claims.

Claims

1. An optical lens, six pieces of lenses in total, characterized in that, In order from the object side to the imaging plane along the optical axis, the optical lens comprises in sequence: a first lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a second lens with positive refractive power, the image side surface of which is a convex surface; a third lens with positive refractive power, the image side surface of which is a convex surface; a fourth lens with refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a fifth lens with negative refractive power, the image side surface of which is a concave surface; a sixth lens with positive refractive power; a radius of curvature R1 of the object side surface of the first lens and a radius of curvature R2 of the image side surface of the first lens satisfy: -0.65 < (R1-R2) / (R1+R2) < -0.1; a radius of curvature R7 of the object side surface of the fourth lens and a radius of curvature R8 of the image side surface of the fourth lens satisfy: |(R7-R8) / (R7+R8)| < 0.75; an optical total length TTL of the optical lens, an image height IH corresponding to a maximum field of view of the optical lens, and a maximum field of view FOV of the optical lens satisfy: 55 < 180°×TTL / (IH / 2) / (FOV / 2) < 80.

2. The optical lens of claim 1, wherein, a radius of curvature R1 of the object side surface of the first lens and a radius of curvature R2 of the image side surface of the first lens satisfy: -0.60 ≤ (R1-R2) / (R1+R2) ≤ -0.

14.

3. The optical lens of claim 1, wherein, a radius of curvature R7 of the object side surface of the fourth lens and a radius of curvature R8 of the image side surface of the fourth lens satisfy: -0.23 ≤ (R7-R8) / (R7+R8) ≤ 0.

69.

4. The optical lens of claim 1, wherein, an optical total length TTL of the optical lens and an effective focal length f of the optical lens satisfy: 1.8 < TTL / f < 2.

5.

5. The optical lens of claim 1, wherein, an image height IH corresponding to a maximum field of view of the optical lens, an effective focal length f of the optical lens, and a maximum field of view FOV of the optical lens satisfy: 0.95 < (IH / 2) / (f×Tan(FOV / 2)) < 1.

1.

6. The optical lens of claim 1, wherein, an optical total length TTL of the optical lens, an image height IH corresponding to a maximum field of view of the optical lens, and a maximum field of view FOV of the optical lens satisfy: 61.69 ≤ 180°×TTL / (IH / 2) / (FOV / 2) ≤ 75.

36.

7. The optical lens of claim 1, wherein, an effective focal length f1 of the first lens and an effective focal length f of the optical lens satisfy: -6 < f1 / f < -1.

5.

8. The optical lens of claim 1, wherein, an effective focal length f4 of the fourth lens and an effective focal length f of the optical lens satisfy: 1.5 < |f4 / f| < 6.

9. The optical lens of claim 1, wherein, a radius of curvature R4 of the image side surface of the second lens and an effective focal length f of the optical lens satisfy: -2.5 < R4 / f < -0.

5.

10. The optical lens of claim 1, wherein, a radius of curvature R10 of the image side surface of the fifth lens and an effective focal length f of the optical lens satisfy: 0.2 < R10 / f < 1.7.

Images