Optical lens

Abstract

This invention provides an optical lens comprising eight lenses of optical power, arranged sequentially along the optical axis from the object side to the image plane: a first lens with negative optical power, having a convex object side and a concave image side; a second lens with negative optical power, having a convex object side and a concave image side; a third lens with positive optical power, having a convex object side and a convex image side; a fourth lens with positive optical power, having a convex object side and a convex image side; a fifth lens with negative optical power, having a concave object side and a concave image side; a sixth lens with positive optical power; a seventh lens with negative optical power, having a convex object side near the optical axis and a concave image side near the optical axis; and an eighth lens with optical power, having a convex object side near the optical axis and a concave image side near the optical axis. The optical lens provided by this invention possesses one or more advantages, including ultra-wide angle, large image plane, high pixel count, large aperture, and high image 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] With the rapid development of outdoor sports, extreme photography, and vlog recording, action cameras are facing increasingly higher demands for lens field of view, image quality, and environmental adaptability. Wide-angle framing, large-format high-definition imaging, and lightweight construction have become the core development directions for action camera lenses, as lens performance directly affects the image quality of dynamic shooting and the overall user experience.

[0003] Current action camera lenses on the market have many shortcomings, making it difficult to balance wide-angle shots with high-quality imaging. Traditional lenses have small target surface sizes, insufficient high-definition imaging capabilities, and severe edge distortion when shooting at wide angles. Furthermore, most use single-glass or all-plastic structures, resulting in poor aberration correction and issues such as edge blurring and color deviation. Pure glass lenses are heavy and expensive, while all-plastic lenses have poor heat resistance and vibration resistance, making them unsuitable for complex outdoor shooting scenarios and failing to meet the needs of high-end action cameras. Summary of the Invention

[0004] To address the above problems, the present invention aims to provide an optical lens with excellent imaging quality.

[0005] The technical solution adopted in this invention is as follows: An optical lens has 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 convex 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. The fourth lens with positive optical power has a convex object-side surface and a convex image-side surface. The fifth lens with negative optical power has a concave object side and a concave image side. A sixth lens with positive optical power; The seventh lens with negative optical power has an object-side surface that is convex near the optical axis and an image-side surface that is concave near the optical axis. The eighth lens, which has optical power, has an object-side surface that is convex near the optical axis and an image-side surface that is concave near the optical axis. The maximum field of view (FOV) of the optical lens and the aperture value (Fno) of the optical lens satisfy the following condition: 59° <FOV / Fno<64°。

[0006] Further preferably, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 3.4<IH / f<3.6.

[0007] Further preferably, the maximum field angle FOV of the optical lens and the chief ray incidence angle CRA at the maximum image height of the optical lens satisfy: 3.9<FOV / CRA<4.2.

[0008] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3<f1 / f<-1.3; 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: 3<R1 / f<57.

[0009] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -4.5<f2 / f<-3.5; 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: 1.1<R3 / f<1.6.

[0010] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.2<f3 / f<1.7; 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: 1.3<R5 / f<1.8.

[0011] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.9<f5 / f<-1.3; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: 0.2<(R9+R10) / (R9-R10)<0.7.

[0012] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -3.4<f7 / f<-1.8; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 0.7<R14 / f<1.9.

[0013] Further preferably, 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: 2.1<f123 / f<3.5; the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 2.7<f45678 / f<4.7.

[0014] Further preferably, the clear aperture semi-diameter CSD11 of the object-side surface of the first lens and the sag SAG11 of the object-side surface of the first lens satisfy: 3<CSD11 / SAG11<82; the clear aperture semi-diameter CSD11 of the object-side surface of the first lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.5<CSD11 / EPD<5.5.

[0015] The optical lens provided by the present invention adopts eight lenses with specific optical power, and can improve the imaging quality of the optical lens, reduce aberrations, improve the imaging quality of the optical lens through matching specific surface shapes and reasonable optical power distribution, so that the lens has one or more advantages such as ultra-wide angle, large image plane, high pixel, large aperture and high imaging quality. Description of Drawings

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easy to understand from the description of embodiments in conjunction with the following drawings, in which: Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 2 is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 is an axial aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 is a vertical chromatic aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 is a central field of view-defocus curve diagram of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 6 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 7 is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 8 is an axial aberration curve diagram of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 9 is a vertical chromatic aberration curve diagram of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 10 is a central field of view-defocus curve diagram of the optical lens in Embodiment 2 of the present invention.

[0026] Figure 11This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0027] Figure 12 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0028] Figure 13 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 14 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 15 This is a diagram showing the center field of view-defocus curve of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 16 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0032] Figure 17 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0033] Figure 18 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0034] Figure 19 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0035] Figure 20 This is a diagram showing the center field of view-defocus curve of the optical lens in Embodiment 4 of the present invention.

[0036] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The optical lens provided in this embodiment of the invention has eight lenses with optical power, which are arranged sequentially from the object side to the imaging plane along the optical axis as 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.

[0045] In some embodiments, the first lens may have negative refractive power, its object-side surface is a convex surface, and its image-side surface is a concave surface. The second lens may have negative refractive power, its object-side surface is a convex surface, and its image-side surface is a concave surface. The third lens may have positive refractive power, its object-side surface is a convex surface, and its image-side surface is a convex surface. The fourth lens may have positive refractive power, its object-side surface is a convex surface, and its image-side surface is a convex surface. The fifth lens may have negative refractive power, its object-side surface is a concave surface, and its image-side surface is a concave surface. The sixth lens may have positive refractive power, its object-side surface may be a concave surface or a convex surface, and its image-side surface may be a concave surface or a convex surface. The seventh lens may have negative refractive power, its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis. The eighth lens may have positive refractive power or negative refractive power, its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis.

[0046] In some embodiments, the optical lens may further include a stop, and the stop may be located between the third lens and the fourth lens. It can be understood that the stop is configured to limit the amount of incident light, so as to adjust the brightness of imaging.

[0047] In some embodiments, the optical lens may further include a filter, and the filter is disposed between the eighth lens and an imaging surface. The filter is configured to filter out interfering light, preventing the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0048] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 59° < FOV / Fno < 64°. Satisfying the above conditional formula enables reasonable configuration of the ratio of the field of view to the F-number of the optical lens, realizes the combined effect of the optical lens having a large field of view and a large aperture, enables the optical lens to have a reasonable amount of incident light, improves the overall illuminance of the imaging picture, and makes the optical lens suitable for different lighting environments.

[0049] In some embodiments, the actual image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 3.4 < IH / f < 3.6. Satisfying the above conditional formula controls the ratio of the effective focal length to the image height of the optical lens. Shortening the effective focal length can expand the field of view, enabling the optical lens to photograph a wider object-side space, meanwhile enabling the optical lens to match a large-image-size chip to meet high pixel requirements, and improving the imaging quality of the optical lens.

[0050] In some embodiments, the maximum field of view FOV of the optical lens and the chief ray angle CRA at the maximum image height of the optical lens satisfy: 3.9 < FOV / CRA < 4.2. Satisfying the above conditional formula enables incident light rays of different field of views of the optical lens to enter the image sensor at an appropriate angle, thereby improving the photosensitive performance of the image sensor and improving the imaging quality of the optical lens.

[0051] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3<f1 / f<-1.3. When the above conditional expression is satisfied, setting the first lens of the optical lens as a lens with negative refractive power can control the incident angle of light, expand the field of view range of the optical lens, increase the back focal length of the optical lens, and avoid interference between the lens and the photosensitive chip.

[0052] In some embodiments, the curvature radius R1 of the object-side surface of the first lens and the effective focal length f of the optical lens satisfy: 3<R1 / f<57. When the above conditional expression is satisfied, designing the first lens as a convex surface helps to converge incident light, increase the light input of the optical lens to improve the intensity of light reaching the imaging surface, and realize an ultra-wide-angle design; it is also beneficial to shorten the total length of the optical lens, so that the optical lens meets the miniaturization design requirement.

[0053] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -4.5<f2 / f<-3.5. When the above conditional expression is satisfied, the second lens can have appropriate negative refractive power, which can share the negative refractive power at the front end of the optical lens, thereby helping to avoid excessive light deflection caused by excessive concentration of refractive power of the first lens, and reducing the difficulty of chromatic aberration correction of the optical lens.

[0054] In some embodiments, the curvature radius R3 of the object-side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.1<R3 / f<1.6. When the above conditional expression is satisfied, this arrangement makes the object-side surface of the second lens convex, so that the light passing through the first lens contracts into the second lens, which can reduce the size of the subsequent lenses, contributes to the miniaturization of the optical lens, and the second lens can effectively reduce the generation of spherical aberration and astigmatism to improve the imaging quality of the optical lens.

[0055] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.2<f3 / f<1.7. When the above conditional expression is satisfied, the third lens has the function of converging light. Matching with the negative refractive power of the first lens and the second lens can further converge the light passing through the second lens, reduce the height of peripheral light, which is conducive to reducing the aperture of the rear lenses, and at the same time helps to balance aberration and improve resolution.

[0056] In some embodiments, the curvature radius R5 of the object-side surface of the third lens and the effective focal length f of the optical lens satisfy: 1.3<R5 / f<1.8. When the above conditional expression is satisfied, by controlling the ratio of the curvature radius of the third lens to the effective focal length of the entire optical lens within a certain range, the astigmatism of the third lens can be kept within a reasonable range, and it can effectively balance the astigmatism generated by the preceding lenses, so that the optical lens has good imaging quality.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.9<f5 / f<-1.3. Satisfying the above range allows the fifth lens to have an appropriate negative optical power, which is beneficial for balancing astigmatism and field curvature of the optical lens and improving the imaging quality of the optical lens.

[0058] In some embodiments, the radius of curvature R9 of the object-side surface of the fifth lens and the radius of curvature R10 of the image-side surface of the fifth lens satisfy: 0.2<(R9+R10) / (R9-R10)<0.7. Satisfying the above conditional expression, designing the fifth lens as a biconcave shape can reasonably increase the incident angle to meet the image height requirement of the optical lens, while reducing the sensitivity of the optical lens and improving assembly stability.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -3.4<f7 / f<-1.8. Satisfying the above conditional expression, adjusting the divergence angle of light and increasing the image plane height by controlling the ratio of the focal length of the seventh lens to the effective focal length.

[0060] In some embodiments, the radius of curvature R14 of the image-side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 0.7<R14 / f<1.9. Satisfying the above conditional expression, controlling the surface shape of the image-side surface of the seventh lens can effectively correct spherical aberration of the optical lens, reduce the influence of astigmatism on the imaging of the optical lens, and additionally adjust the propagation trend of light, enabling the optical lens to have a large field of view and ultra-thinning.

[0061] 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: 2.1<f123 / f<3.5; the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 2.7<f45678 / f<4.7. Satisfying the above conditional expression, reasonably setting the positive refractive power of the lens groups before and after the diaphragm is beneficial to balancing the distortion and astigmatism generated by the front and rear end lenses of the optical lens, and improving the imaging quality of the optical lens.

[0062] In some embodiments, the clear aperture semi-diameter CSD11 of the object-side surface of the first lens and the sag SAG11 of the object-side surface of the first lens satisfy: 3<CSD11 / SAG11<82. Satisfying the above conditional expression, limiting the object-side surface of the first lens enables the optical lens to meet the design requirement of small aperture, which is beneficial to compressing the central field of view of the optical lens and makes the imaging quality of the marginal field of view better.

[0063] In some embodiments, the clear half-aperture CSD11 of the object side surface of the first lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.5<CSD11 / EPD<5.5. Satisfying the above conditional expression can control the ratio of the clear half-aperture of the object side surface of the first lens to the entrance pupil diameter of the optical lens within a reasonable range, which is beneficial to the wide-angle characteristic of the optical lens; in addition, it is also beneficial for the optical lens to obtain sufficient luminous flux, avoiding dark corners in the image plane obtained by shooting, and improving the imaging quality.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.1<f4 / f<1.3. Satisfying the above conditional expression, by arranging the fourth lens to have a large positive refractive power, it can converge the light from the first three lenses, correct the aberration problems caused by the first three lenses, effectively improve the aberration of the edge field of view, and improve the overall imaging quality of the optical lens.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 3<f6 / f<18. Satisfying the above conditional expression, the positive refractive power intensity provided by the sixth lens for the optical lens can better constrain the rear-end light rays, thereby effectively correcting chromatic aberration. Meanwhile, as a lens at the rear-end position of the optical lens, the sixth lens can better correct the aberration caused by the eccentricity difference of each lens on the object side, that is, it can reduce the eccentricity sensitivity of the optical lens, suppress the astigmatism caused by the eccentricity of each lens on the object side, thereby realizing the correction of the aberration of the optical lens and improving the imaging resolution.

[0066] In some embodiments, the clear half-aperture CSD11 of the object side surface of the first lens and the clear half-aperture CSD81 of the object side surface of the eighth lens satisfy: 0.8<CSD11 / CSD81<1.7. Satisfying the above conditional expression, by controlling the ratio of the clear half-aperture of the object side end of the first lens to the clear half-aperture of the object side end of the eighth lens, the optical lens can have a smaller aperture size, which is convenient to be mounted on sports equipment; at the same time, it ensures that the optical lens can collect large-angle light, realize large-field-angle imaging of the optical lens, increase the imaging area of the optical lens, and improve the imaging quality.

[0067] In some embodiments, the effective focal length f of the optical lens and the aperture value Fno of the optical lens satisfy: 1.3mm<f / Fno<1.4mm. Satisfying the above conditional expression is conducive to the optical lens obtaining the characteristic of large aperture, so that the optical lens has sufficient light intake, which is further conducive to making the captured image clearer; meanwhile, the short focal length matched with large aperture enables the optical lens to have a large wide-angle field of view to capture more scene information, solve the low-light shooting problem through the large aperture, and strengthen the picture layering through flexible depth of field control.

[0068] In some embodiments, the optical lens satisfies the conditional expressions: 3.5mm < f < 3.7mm; 16mm < TTL < 18mm; 155° < FOV < 165°; 1.3mm < EPD < 1.4mm; 2.5 < Fno < 2.7; 39° < CRA < 40°; 12mm < IH < 13mm; wherein f represents the effective focal length of the optical lens, TTL represents the total optical 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, Fno represents the F-number of the optical lens, CRA represents the chief ray incidence angle at the maximum image height of the optical lens, and IH represents the real image height corresponding to the maximum field of view of the optical lens. Satisfying the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least one or more of the advantages of short focal length, large field of view, small entrance pupil diameter, short total length, large aperture, large image surface, and low sensitivity.

[0069] In various embodiments of the present invention, when an aspheric lens is adopted for the lens, the shape of each aspheric surface of the optical lens satisfies the following equation: ; wherein z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic constant, and B, C, D, E, F, G, H are respectively the 4th-order, 6th-order, 8th-order, 10th-order, 12th-order, 14th-order, 16th-order curved surface coefficients.

[0070] The present invention will be further described below with reference to multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different to some extent. 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 only by the following embodiments. Any other changes, substitutions, combinations or simplifications made without departing from the innovative concepts of the present invention shall be regarded as equivalent replacement modes, and are all included within the protection scope of the present invention.

[0071] Example 1

[0072] Please refer to Figure 1 , which is a schematic structural diagram of the optical lens 100 provided in Example 1 of the present invention. The optical lens sequentially includes, along the optical axis from the object side to the imaging surface: a first lens L1, a second lens L2, a third lens L3, a stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0073] wherein, the first lens L1 has negative optical power, its object-side surface S1 is a convex surface, and its image-side surface S2 is a concave surface; The second lens L2 has negative optical power, its object side S3 is convex, 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 positive optical power, its object side S7 is convex, and its image side S8 is convex. The fifth lens L5 has negative optical power, its object side S9 is concave, and its image side S10 is concave. The sixth lens L6 has positive optical power, its object side S11 is convex, and its image side S12 is concave. The seventh lens L7 has negative optical power. Its object-side surface S13 is convex near the optical axis, and its image-side surface S14 is concave near the optical axis. The eighth lens L8 has positive optical power, its object side S15 is convex near the optical axis, and its image side S16 is concave near the optical axis. The object-side surface S17 and the image-side surface S18 of filter G1 are both planar. The imaging plane S19 is a plane.

[0074] The first lens L1 is a glass spherical lens, the third lens L3 is a glass aspherical lens, and the second lens L2, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are plastic aspherical lenses.

[0075] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0076] Table 1-1

[0077] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0078] Table 1-2

[0079] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and central field-defocus curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0080] Figure 2The field curvature curve of Example 1 is shown, which represents the degree of curvature 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 field curvature of the meridional and sagittal image planes is controlled within ±0.05 mm, indicating that the optical lens can effectively correct the field curvature.

[0081] Figure 3 The diagram shows the axial aberration curves for Example 1, representing the aberrations of each wavelength along 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. The diagram shows that the axial aberration offset is controlled within ±0.02 mm, indicating that the optical lens can effectively correct axial aberrations.

[0082] Figure 4 The diagram shows the transverse chromatic aberration curves for Example 1, representing 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 -3 μm to 6 μm, indicating that the optical lens can effectively correct chromatic aberration.

[0083] Figure 5 The diagram shows the center field-out-of-focus curve of Example 1, which represents the lens imaging modulation at a spatial frequency of 110 lp / mm. The horizontal axis represents the focus shift (unit: mm), and the vertical axis represents the OTF value. As can be seen from the figure, the OTF value at the center field of view is greater than 75% at both high temperature (80°C) and low temperature (-40°C), indicating that the lens has good resolving power at both high and low temperatures.

[0084] Example 2

[0085] Please see Figure 6 The figure shown is 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 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 200 in Example 2 are shown in Table 2-1.

[0087] Table 2-1

[0088] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0089] Table 2-2

[0090] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and central field-defocus curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0091] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.1mm to 0.05mm, indicating that the optical lens can effectively correct the field curvature.

[0092] from Figure 8 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens can effectively correct axial aberration.

[0093] from Figure 9 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3μm to 5μm, indicating that the optical lens can correct chromatic aberration well.

[0094] from Figure 10 As can be seen, the OTF value at the center field of view is greater than 70% at both high temperature (80°C) and low temperature (-40°C), indicating that the lens has good resolution at both high and low temperatures.

[0095] Example 3

[0096] Please see Figure 11 The figure shown is 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 optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0097] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0098] Table 3-1

[0099] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0100] Table 3-2

[0101] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and central field-defocus curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0102] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.05mm, indicating that the optical lens can effectively correct the field curvature.

[0103] from Figure 13 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens can effectively correct axial aberration.

[0104] from Figure 14 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 6μm, indicating that the optical lens can correct chromatic aberration well.

[0105] from Figure 15 As can be seen, the OTF value at the center field of view is greater than 65% at both high temperature (80°C) and low temperature (-40°C), indicating that the lens has good resolution at both high and low temperatures.

[0106] Example 4

[0107] Please see Figure 16 The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the eighth lens L8 has negative optical power; the object side S11 of the sixth lens L6 is concave; the image side S12 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0108] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0109] Table 4-1

[0110] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0111] Table 4-2

[0112] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and central field-defocus curve of the optical lens 400 are respectively as follows: Figure 17 , Figure 18 , Figure 19 , Figure 20 As shown.

[0113] from Figure 17As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.1mm to 0.05mm, indicating that the optical lens can effectively correct the field curvature.

[0114] from Figure 18 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens can effectively correct axial aberration.

[0115] from Figure 19 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 6μm, indicating that the optical lens can correct chromatic aberration well.

[0116] from Figure 20 As can be seen, the OTF value at the center field of view is greater than 75% at both high temperature (80°C) and low temperature (-40°C), indicating that the lens has good resolution at both high and low temperatures.

[0117] Please refer to Table 5 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, maximum field of view FOV, and the value corresponding to each conditional expression in each embodiment.

[0118] Table 5

[0119] In summary, the optical lens provided by the present invention employs 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 ultra-wide angle, large image plane, high pixel count, large aperture, and high imaging quality.

[0120] 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.

[0121] 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, It sequentially comprises from the object side to the imaging surface along the optical axis: a first lens having negative refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a second lens having negative refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a third lens having positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a convex surface; a fourth lens having positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a convex surface; a fifth lens having negative refractive power, the object side surface of which is a concave surface and the image side surface of which is a concave surface; a sixth lens having positive refractive power; a seventh lens having negative refractive power, the object side surface of which is convex near the optical axis and the image side surface of which is concave near the optical axis; an eighth lens having refractive power, the object side surface of which is convex near the optical axis and the image side surface of which is concave near the optical axis; wherein, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 59°<FOV / Fno<64°.

2. The optical lens according to claim 1, characterized in that, the real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 3.4<IH / f<3.

6.

3. The optical lens according to claim 1, characterized in that, the maximum field of view FOV of the optical lens and the chief ray angle CRA at the maximum image height of the optical lens satisfy: 3.9<FOV / CRA<4.

2.

4. 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: -2.3<f1 / f<-1.3; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 3<R1 / f<57.

5. 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: -4.5<f2 / f<-3.5; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.1<R3 / f<1.

6.

6. 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: 1.2<f3 / f<1.7; the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 1.3<R5 / f<1.

8.

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: -1.9<f5 / f<-1.3; the curvature radius R9 of the object side surface of the fifth lens and the curvature radius R10 of the image side surface of the fifth lens satisfy: 0.2<(R9+R10) / (R9-R10)<0.

7.

8. 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: -3.4<f7 / f<-1.8; the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 0.7<R14 / f<1.

9.

9. The optical lens according to claim 1, characterized in that, 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: 2.1<f123 / f<3.5; the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 2.7<f45678 / f<4.

7.

10. The optical lens according to claim 1, characterized in that, The clear aperture half-diameter CSD11 of the object-side surface of the first lens and the sag SAG11 of the object-side surface of the first lens satisfy: 3<CSD11 / SAG11<82; the clear aperture half-diameter CSD11 of the object-side surface of the first lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.5<CSD11 / EPD<5.5.

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