Optical lens

Abstract

The invention provides an optical lens, which comprises eight lenses with focal power and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from an object side to an imaging surface along an optical axis, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface; the fourth lens has positive focal power; the fifth lens has positive focal power, and the object side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a concave surface; the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a convex surface; and the object side surface of the eighth lens is a convex surface, and the image side surface of the eighth lens is a concave surface. According to the optical lens provided by the invention, the imaging quality of the optical lens can be improved, and the optical lens has the advantage of excellent imaging quality.

Description

Technical Field

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

[0002] In recent years, with the rapid development of drones, their application areas have become increasingly wider, ranging from simple aerial photography to complex environmental monitoring, agricultural plant protection, topographic mapping, and even emergency rescue; the requirements for lenses have also become increasingly higher. However, these traditional lenses often use all-glass lenses, resulting in large size and heavy weight, which not only limits the miniaturization design of the equipment but also increases manufacturing costs; moreover, the existing optical lenses have small apertures, leading to unclear image quality. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0004] This invention provides an optical lens comprising eight 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 convex 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; A fourth lens with positive optical power; The fifth lens with positive optical power has a convex object-side surface; The sixth lens has negative optical power, with both its object-side and image-side surfaces being concave. The seventh lens with positive optical power has a convex object-side surface and a convex image-side surface. The eighth lens, which has negative optical power, has a convex object side and a concave image side. The true image height IH corresponding to the maximum field of view of the optical lens, the total optical length TTL of the optical lens, and the aperture value Fno of the optical lens satisfy the following condition: 0.7 < Fno × IH / TTL < 1.

[0005] Further preferably, the combined focal length f12345 of the first lens, the second lens, the third lens, the fourth lens and the fifth lens satisfies the following condition with respect to the effective focal length f of the optical lens: 0.7 < f12345 / f < 1.1.

[0006] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.6 < f1 / f < -2.5.

[0007] More preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -2.5 < f2 / f < -2.1; the object side radius of curvature R3 of the second lens and the image side radius of curvature R4 of the second lens satisfy: 0.3 < (R3 + R4) / (R3 - R4) < 0.5.

[0008] More preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2.7 < f3 / f < 3.8; the radius of curvature R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: 1.4 < R5 / f < 3.9.

[0009] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 3.8 < f4 / f < 12.3.

[0010] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.1 < f5 / f < 1.6.

[0011] More preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.1 < f6 / f < -1.3; the object side radius of curvature R11 of the sixth lens and the image side radius of curvature R12 of the sixth lens satisfy: 0.3 < (R11 + R12) / (R11 - R12) < 0.8.

[0012] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.1 < f7 / f < 1.6.

[0013] Further preferably, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -3.5 < f8 / f < -2.5; the object side radius of curvature R15 of the eighth lens and the image side radius of curvature R16 of the eighth lens satisfy: 1.2 < (R15 + R16) / (R15 - R16) < 3.4.

[0014] Compared with existing technologies, the optical lens provided by this invention uses eight lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as miniaturization, large aperture, ultra-wide angle, high pixel count, and high imaging quality. Attached Figure Description

[0015] 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: Figure 1This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0016] Figure 2 This is an astigmatism curve diagram of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 3 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 4 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 5 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0020] Figure 6 This is an astigmatism curve of the optical lens in Embodiment 2 of the present invention.

[0021] Figure 7 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 8 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 9 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0024] Figure 10 This is an astigmatism curve diagram of the optical lens in Embodiment 3 of the present invention.

[0025] Figure 11 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0026] Figure 12 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0027] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The optical lens provided in this embodiment of the invention has eight lenses with optical power, which are arranged sequentially along the optical axis from the object side to the imaging plane as follows: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens.

[0036] In some embodiments, the first lens may have negative optical power, with a convex object-side surface and a concave image-side surface. The second lens may have negative optical power, with both its object-side and image-side surfaces being concave. The third lens may have positive optical power, with a convex object-side surface and either a concave or convex image-side surface. The fourth lens may have positive optical power, with both its object-side and image-side surfaces being concave or convex. The fifth lens may have positive optical power, with both its object-side and image-side surfaces being concave or convex. The sixth lens may have negative optical power, with both its object-side and image-side surfaces being concave. The seventh lens may have positive optical power, with both its object-side and image-side surfaces being convex. The eighth lens may have negative optical power, with both its object-side and image-side surfaces being concave.

[0037] In some embodiments, the optical lens may also include an aperture stop, which may be located between the fifth and sixth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens, thereby altering the brightness of the image.

[0038] In some embodiments, the optical lens may further include a filter disposed between the eighth lens and the imaging surface. The filter is used to filter out interfering light and prevent it from reaching the imaging surface of the optical lens and affecting normal imaging.

[0039] In some implementations, the true image height (IH) corresponding to the maximum field of view of the optical lens, the total optical length (TTL) of the optical lens, and the aperture value (Fno) of the optical lens satisfy the following condition: 0.7 < Fno × IH / TTL < 1. Meeting this condition allows for a slim and miniaturized optical lens design while simultaneously providing a larger image plane and a larger aperture. This enables the optical lens to better match higher-resolution image sensors, effectively improving image quality. Furthermore, it provides sufficient light transmission, improving low-light shooting conditions and resulting in more vivid and lifelike images, meeting the demands for high-quality, high-definition shooting.

[0040] In some embodiments, the combined focal length f12345 of the first, second, third, fourth, and fifth lenses satisfies the condition that 0.7 < f12345 / f < 1.1 with the effective focal length f of the optical lens. Satisfying this condition allows the first to fifth lenses to share the optical power of the front lens group, ensuring a balance in the incident angle of the front lens group, thus reducing lens sensitivity, minimizing distortion, and improving lens stability.

[0041] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy the condition: -4.6 < f1 / f < -2.5. By satisfying the above condition and setting the first lens of the optical lens as a lens with negative optical power, the incident angle of light can be controlled, the field of view range of the optical lens can be expanded, and the back focal length of the optical lens can be increased to avoid interference between the lens and the photosensitive chip.

[0042] In some implementations, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy the condition: -2.5 < f2 / f < -2.1. Satisfying this condition ensures that the second lens has a negative focal length, guaranteeing that the light beam entering the second lens diverges, allowing the light to rise gradually over a wide field of view. This is beneficial for achieving a large aperture and a large target surface, while also promoting a smoother light path, reducing aberrations, and ultimately achieving high imaging quality.

[0043] In some embodiments, the object-side radius of curvature R3 and the image-side radius of curvature R4 of the second lens satisfy the condition: 0.3 < (R3 + R4) / (R3 - R4) < 0.5. By satisfying this condition, the second lens is designed as a biconcave type, ensuring that it can better diverge light, thereby reducing the risk of ghosting and improving the system's resolving power.

[0044] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy the condition: 2.7 < f3 / f < 3.8. By satisfying the above condition and setting a third lens with positive optical power, and limiting the ratio of the focal length of the third lens to the effective focal length of the optical lens, it is advantageous to adjust the light trajectory from the first lens and the second lens, so that the optical lens has the characteristics of a large field of view, low sensitivity, and miniaturization.

[0045] In some embodiments, the radius of curvature R5 of the object-side surface of the third lens satisfies the condition 1.4 < R5 / f < 3.9 with the effective focal length f of the optical lens. This condition ensures that the object-side surface of the third lens is convex, causing light rays passing through the second lens to be compressed into the third lens. This reduces the size of the subsequent lenses, contributing to the miniaturization of the optical lens. Furthermore, the third lens effectively reduces spherical aberration and astigmatism, thereby improving the imaging quality of the optical lens.

[0046] In some implementations, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy the condition: 3.8 < f4 / f < 12.3. By satisfying this condition and setting the fourth lens to have a large positive refractive power, the light rays from the first three lenses can be converged, and the aberrations caused by the first three negative focal length lenses can be corrected. Furthermore, it can effectively improve aberrations at the edges of the field of view, thereby enhancing the overall imaging quality of the optical lens.

[0047] In some implementations, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy the condition: 1.1 < f5 / f < 1.6. Satisfying this condition, in conjunction with the fourth lens, further restricts the direction of light rays and helps correct aberrations caused by the refraction of light rays by the preceding lenses, thus ensuring image quality.

[0048] In some implementations, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy the condition: -2.1 < f6 / f < -1.3. By satisfying this condition and reasonably controlling the focal length of the sixth lens, the light rays in the large field of view are gradually raised, causing the parallel light trend of the beam to change into a divergent trend. This is beneficial for controlling the back focal length of the lens, achieving a large target surface, and reducing the incident angle of the principal ray.

[0049] In some embodiments, the object-side radius of curvature R11 of the sixth lens and the image-side radius of curvature R12 of the sixth lens satisfy the condition: 0.3 < (R11 + R12) / (R11 - R12) < 0.8. Satisfying the above condition can correct the edge aberrations of the optical lens, suppress astigmatism, control the angle of the principal ray incident on the image plane from the peripheral viewing angle, and improve the resolution of the optical lens.

[0050] In some implementations, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy the condition: 1.1 < f7 / f < 1.6. Satisfying this condition, the positive refractive power provided by the seventh lens to the optical lens can effectively constrain the rear-end light rays, thereby effectively correcting chromatic aberration. Simultaneously, as the rear-end lens in the optical lens, the seventh lens can better correct aberrations caused by the eccentricity of the object-side lenses, thus reducing the eccentricity sensitivity of the optical lens and suppressing astigmatism caused by eccentricity in the object-side lenses. This achieves aberration correction of the optical lens and improves image resolution.

[0051] In some implementations, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy the condition: -3.5 < f8 / f < -2.5. By controlling the ratio of the radius of curvature of the image-side surface of the eighth lens to the effective focal length, the light divergence angle is adjusted, thereby increasing the image plane height.

[0052] In some embodiments, the object-side radius of curvature R15 of the eighth lens and the image-side radius of curvature R16 of the eighth lens satisfy the following condition: 1.2 < (R15 + R16) / (R15 - R16) < 3.4. Satisfying the above condition helps to correct aberrations generated by the optical lens under large image plane conditions, making the optical power configuration of the optical lens uniform in the direction perpendicular to the optical axis, which can significantly correct the distortion and aberrations generated by the preceding lens; it also avoids excessive curvature of the surface of the eighth lens, making the eighth lens easier to form and manufacture.

[0053] In some implementations, the maximum field of view (FOV) of the optical lens and the entrance pupil diameter (EPD) of the optical lens satisfy the following condition: 115° / mm < FOV / EPD < 190° / mm. Meeting this condition allows the optical lens to have a large field of view and a large entrance pupil diameter, while ensuring a large aperture effect and a long depth of field. This enables the optical lens to achieve clear imaging of distant objects at large angles while still maintaining clear recognition of nearby objects, resulting in high image quality.

[0054] In some embodiments, the half-aperture diameter (CSD11) of the object-side surface of the first lens and the half-aperture diameter (CSD81) of the object-side surface of the eighth lens satisfy the condition: 1.3 < CSD11 / CSD81 < 3.4. By controlling the ratio of the half-aperture diameters of the object-side surface of the first lens and the eighth lens, the optical lens can have a smaller aperture size, making it easier to mount on drone equipment. Simultaneously, it ensures that the optical lens can collect light at a large angle, achieving wide field-of-view imaging, increasing the imaging area of ​​the optical lens, and improving image quality.

[0055] In some embodiments, the half-aperture diameter (CSD11) of the object-side surface of the first lens and the entrance pupil diameter (EPD) of the optical lens satisfy the following condition: 1.9 < CSD11 / EPD < 3.4. Satisfying this condition allows the ratio of the half-aperture diameter of the object-side surface of the first lens to the entrance pupil diameter of the optical lens to be controlled within a reasonable range, which is beneficial to the wide-angle characteristics of the optical lens. Furthermore, it helps the optical lens obtain sufficient light throughput, avoids vignetting in the captured image, and improves image quality.

[0056] In some embodiments, the object-side half-aperture CSD21 of the second lens and the sagitta SAG21 of the object-side half-aperture of the second lens satisfy the condition: -8.1 < CSD21 / SAG21 < -6.1. Satisfying this condition allows for effective control of the size of the object-side half-aperture of the second lens. This, combined with controlling the sagitta at the maximum object-side half-aperture of the second lens, can further reduce the size of the optical lens and decrease the risk of ghosting.

[0057] In some embodiments, the optical lens satisfies the following conditions: 1.6mm < f < 2.5mm; 195° < FOV < 210°; 1.1mm < EPD < 1.7mm; 8.6mm < TTL < 11mm; 1.45 ≤ Fno ≤ 1.5; 5.3mm < IH < 5.8mm; 36° < CRA < 56°; where f represents the effective focal length of the optical lens, FOV represents the maximum field of view of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view of the optical lens, and CRA represents the principal ray incident angle at the maximum image height of the optical lens. Satisfying the above conditions, the optical lens possesses at least one or more advantages of short focal length, ultra-wide field of view, large entrance pupil diameter, short total length, large aperture, large image plane, low distortion, and low sensitivity.

[0058] In some embodiments, the eight lenses in the optical lens can all be made of plastic or a combination of glass and plastic materials. Preferably, the optical lens of the present invention uses an eight-lens structure with a combination of glass and plastic materials, which can improve thermal stability. Specifically, the first and fifth lenses can be made of glass, while the second, third, fourth, sixth, seventh, and eighth lenses can be made of plastic. Using a glass-plastic hybrid structure can effectively reduce costs, correct aberrations, reduce size, and provide a more cost-effective optical lens product.

[0059] In some embodiments, the first, second, third, fourth, fifth, sixth, seventh, and eighth 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, in the optical lens provided by this invention, the first lens is a spherical lens, while the second, third, fourth, fifth, sixth, seventh, and eighth lenses are all aspherical lenses.

[0060] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations: ; 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 B, C, D, E, F, G, and H are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0061] 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.

[0062] Example 1 Please see Figure 1 The figure shown is a schematic diagram 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 S19, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture ST, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1. Among them, the first lens L1 has negative optical power, its object side S1 is convex, 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 concave. The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side S8 is concave. 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 concave. The seventh lens L7 has positive optical power, its object side S13 is convex, and its image side S14 is convex. The eighth lens L8 has negative optical power, its object side S15 is convex, and its image side S16 is concave. The object-side surface S17 and the image-side surface S18 of filter G1 are both planar. The imaging plane S19 is a plane.

[0063] The first lens L1 is a glass spherical lens; the fifth lens L5 is a glass aspherical lens; the second lens L2, the third lens L3, the fourth lens L4, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are all plastic aspherical lenses.

[0064] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0065] Table 1-1 The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0066] Table 1-2 In this embodiment, the astigmatism curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 As shown.

[0067] Figure 2 The diagram shows the astigmatism curve of the optical lens 100 in this embodiment, which represents the astigmatism of light 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 astigmatism in the meridional and sagittal image planes is controlled within ±0.1 mm, indicating that the optical lens 100 can correct astigmatism well.

[0068] Figure 3 The diagram shows the axial aberration curve of the optical lens 100 in this embodiment, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -0.03 mm to 0.05 mm, indicating that the optical lens 100 can correct axial aberration well.

[0069] Figure 4 The diagram shows the transverse chromatic aberration curve of the optical lens 100 in this embodiment. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±4 μm, indicating that the optical lens 100 can effectively correct chromatic aberration.

[0070] Example 2 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 main difference between this embodiment and Embodiment 1 is that: the image-side surface S6 of the third lens L3 is convex; the object-side surface S7 of the fourth lens L4 is concave; the image-side surface S8 of the fourth lens L4 is convex; the image-side surface S10 of the fifth lens L5 is concave near the optical axis; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0071] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0072] Table 2-1 The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0073] Table 2-2 In this embodiment, the astigmatism curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0074] from Figure 6 As can be seen, the astigmatism in the meridional and sagittal image planes is controlled within ±0.05mm, indicating that the optical lens 200 can effectively correct astigmatism. From Figure 7 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 200 can effectively correct axial aberration. From Figure 8 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -2μm to 4μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0075] Example 3 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 main difference between this embodiment and Embodiment 1 is that: the image-side surface S6 of the third lens L3 is a convex surface; the object-side surface S7 of the fourth lens L4 is a concave surface; the image-side surface S8 of the fourth lens L4 is a convex surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0076] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0077] Table 3-1 The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0078] Table 3-2 In this embodiment, the astigmatism curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown.

[0079] from Figure 10As can be seen, the astigmatism in the meridional and sagittal image planes is controlled within ±0.1mm, indicating that the optical lens 300 can effectively correct astigmatism. From Figure 11 As can be seen, the axial aberration offset is controlled within ±0.04mm, indicating that the optical lens 300 can effectively correct axial aberration. From Figure 12 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -2μm to 4μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0080] 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, and the values ​​corresponding to each conditional expression in each embodiment.

[0081] Table 4 In summary, the optical lens provided by this invention employs an eight-element glass-plastic hybrid structure. Through specific surface shape settings and reasonable power distribution, the optical lens structure is relatively compact, effectively shortening the overall length of the optical lens and facilitating miniaturization. It features a large aperture, enabling high-definition imaging even in low-light environments. Simultaneously, it has an ultra-wide angle, providing a large field of view. Furthermore, it can reasonably correct overall aberrations of the optical lens, exhibiting high pixel count and improving the image quality of the optical lens.

[0082] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," and "some examples" 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.

[0083] 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 eight lenses having optical power, characterized in that, Along the optical axis from the object side to the imaging plane, the following are included in sequence: The first lens with negative optical power has a convex 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; A fourth lens with positive optical power; The fifth lens with positive optical power has a convex object-side surface; The sixth lens has negative optical power, with both its object-side and image-side surfaces being concave. The seventh lens with positive optical power has a convex object-side surface and a convex image-side surface. The eighth lens, which has negative optical power, has a convex object side and a concave image side. The true image height IH corresponding to the maximum field of view of the optical lens, the total optical length TTL of the optical lens, and the aperture value Fno of the optical lens satisfy the following condition: 0.7 < Fno × IH / TTL < 1.

2. The optical lens according to claim 1, characterized in that, The combined focal length f12345 of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens satisfies the following condition with respect to the effective focal length f of the optical lens: 0.7 < f12345 / f < 1.

1.

3. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy the condition: -4.6 < f1 / f < -2.

5.

4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -2.5 < f2 / f < -2.1; the object side radius of curvature R3 of the second lens and the image side radius of curvature R4 of the second lens satisfy: 0.3 < (R3 + R4) / (R3 - R4) < 0.

5.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy the following condition: 2.7 < f3 / f < 3.8; the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy the following condition: 1.4 < R5 / f < 3.

9.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy the condition: 3.8 < f4 / f < 12.

3.

7. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy the condition: 1.1 < f5 / f < 1.

6.

8. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.1 < f6 / f < -1.3; the object side radius of curvature R11 of the sixth lens and the image side radius of curvature R12 of the sixth lens satisfy: 0.3 < (R11 + R12) / (R11 - R12) < 0.

8.

9. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy the condition: 1.1 < f7 / f < 1.

6.

10. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -3.5 < f8 / f < -2.5; the object side radius of curvature R15 of the eighth lens and the image side radius of curvature R16 of the eighth lens satisfy: 1.2 < (R15 + R16) / (R15 - R16) < 3.4.

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