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 positive optical power, having a convex object side and a concave image side; a third lens with positive optical power, having a concave object side and a convex image side; a fourth lens with optical power, having a convex object side and a concave image side; a fifth lens with positive optical power, having a convex object side and a convex image side; a sixth lens with negative optical power, having a concave object side and a concave image side; a seventh lens with negative optical power, having a convex object side and a concave image side; and an eighth lens with positive optical power, having a convex image side. The optical lens provided by this invention has one or more advantages, including a large field of view, miniaturization, a large aperture, a large image plane, and high image quality.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, in particular to an optical lens. Background Art

[0002] In recent years, with the rapid development of unmanned aerial vehicles, their application fields have become increasingly broad, ranging from simple aerial photography to complex environmental monitoring, agricultural plant protection, topographic surveying and mapping, and even emergency rescue; the requirements for lenses are also getting higher and higher. However, these traditional lenses usually use all-glass lenses, which have the problems of large volume and heavy weight, which not only limits the miniaturization design of equipment, but also increases manufacturing costs. At the same time, due to the small field of view and small aperture, traditional lenses cannot meet the wide-angle shooting requirements of unmanned aerial vehicles, and the imaging quality of traditional lenses is low. Summary of the Invention

[0003] In view of the above problems, an object of the present invention is to provide an optical lens, which has the advantages of miniaturization, large field of view, high image quality and the like.

[0004] The technical solution adopted by the present invention is as follows: An optical lens, in which the number of lenses with optical power is eight, sequentially includes from the object side to the imaging surface along the optical axis: A first lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; A second lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; A third lens with positive optical power, wherein the object side surface thereof is a concave surface, and the image side surface thereof is a convex surface; A fourth lens with optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; A fifth lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface; A sixth lens with negative optical power, wherein the object side surface thereof is a concave surface, and the image side surface thereof is a concave surface; A seventh lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; An eighth lens with positive optical power, wherein the image side surface thereof is a convex surface; Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6.5<TTL / f<9.5; the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 100°<FOV / Fno<115°.

[0005] Further preferably, the effective focal length f of the optical lens and the aperture value Fno of the optical lens satisfy: 1.3mm<f / Fno<1.9mm.

[0006] Further preferably, the clear aperture half-diameter CSD11 of the object side of the first lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.4<CSD11 / IH<0.9.

[0007] Further preferably, 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: 1.5<f45678 / f<2.5.

[0008] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.7<f1 / f<-1.4; the curvature radius R1 of the object side of the first lens, the curvature radius R2 of the image side of the first lens and the focal length f1 of the first lens satisfy: -6<(R1+R2) / f1<-5.

[0009] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 3<f2 / f<11; the curvature radius R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: 2<R3 / f<4.5.

[0010] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.1<f3 / f<4.8; the curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: -2.8<R5 / f<-1.7.

[0011] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.9<f5 / f<1.9; the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: 0.3<(R9+R10) / (R9-R10)<0.6.

[0012] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.4<f6 / f<-0.9; the curvature radius R11 of the object side of the sixth lens and the curvature radius R12 of the image side of the sixth lens satisfy: -1.1<(R11+R12) / (R11-R12)<-0.8.

[0013] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -195<f7 / f<-30; the curvature radius R14 of the image side of the seventh lens and the effective focal length f of the optical lens satisfy: 3<R14 / f<16.

[0014] Further preferably, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 0.7 <f8 / f<1.2。

[0015] 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 a large field of view, miniaturization, large aperture, large image plane, and high imaging quality. 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: Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0017] Figure 2 This is an astigmatism curve diagram of the optical lens in Embodiment 1 of the present invention.

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

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

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

[0021] Figure 6 This is an astigmatism curve of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 7 This is an axial chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

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

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

[0025] Figure 10 This is an astigmatism curve diagram of the optical lens in Embodiment 3 of the present invention.

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

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

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

[0029] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

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

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

[0032] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

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

[0034] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a 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.

[0035] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other if there is no conflict. Hereinafter, the present application will be described in detail with reference to the accompanying drawings in conjunction with the embodiments.

[0036] In the optical lens provided by the embodiment of the present invention, the number of lenses with optical power is eight, which are sequentially 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 along the optical axis from the object side to the imaging surface.

[0037] In some embodiments, the first lens may have negative optical power, with its object side being a convex surface and its image side being a concave surface. The second lens may have positive optical power, with its object side being a convex surface and its image side being a concave surface. The third lens may have positive optical power, with its object side being a concave surface and its image side being a convex surface. The fourth lens may have positive optical power or negative optical power, with its object side being a convex surface and its image side being a concave surface. The fifth lens may have positive optical power, with its object side being a convex surface and its image side being a convex surface. The sixth lens may have negative optical power, with its object side being a concave surface and its image side being a concave surface. The seventh lens may have negative optical power, with its object side being a convex surface and its image side being a concave surface. The eighth lens may have positive optical power, with its object side being a concave surface or a convex surface, and its image side being a convex surface; In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of incoming light to change the brightness of the imaging. When the diaphragm is located between the third lens and the fourth lens, it is convenient to correct the diaphragm aberration.

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

[0039] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6.5<TTL / f<9.5. Satisfying the above conditional expression enables the ratio of the total length of the optical lens to the focal length of the optical lens to be controlled within a reasonable range, thereby realizing miniaturization of the optical lens, facilitating better convergence of light on the imaging surface, and helping to improve the imaging quality of the optical lens.

[0040] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 100°<FOV / Fno<115°. Satisfying the above conditional expression enables a reasonable configuration of the ratio between the field of view and the f-number of the optical lens, achieving the combined effect of the optical lens having a large field of view and a large aperture. The optical lens has a reasonable amount of incoming light, which improves the overall illuminance of the imaged picture, making the optical lens applicable to different lighting environments.

[0041] 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<1.9mm. Satisfying the above conditional expression is beneficial for the optical lens to obtain the characteristic of a large aperture, so that the optical lens has a sufficient amount of incoming light, which is thus conducive to making the captured image clearer; at the same time, the short focal length matched with the large aperture enables the optical lens to have a wide-angle field of view to capture more scene information, while the large aperture solves the problem of low-light shooting, and flexible depth of field control enhances the layering of the picture.

[0042] In some embodiments, the clear semi-aperture CSD11 on the object side of the first lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.4<CSD11 / IH<0.9. Satisfying the above conditional expression enables a reasonable configuration of the ratio between the maximum effective aperture on the object side of the first lens and the image height corresponding to the maximum field of view of the optical lens, which is beneficial to reasonably control the size of the object side of the first lens and realize the miniaturization of the optical lens.

[0043] In some embodiments, 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: 1.5<f45678 / f<2.5. Satisfying the above conditional expression, by reasonably setting the positive refractive power of the lens group behind the diaphragm, is beneficial to balance the distortion and astigmatism generated by the front-end lens of the optical lens, and improve the imaging quality of the optical lens.

[0044] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.7<f1 / f<-1.4. Satisfying the above conditional expression, the first lens of the optical lens is set as a lens with negative optical power, which can control the incident angle of light rays, expand the field of view range of the optical lens, and at the same time increase the back focal length of the optical lens to avoid interference between the lens and the photosensitive chip.

[0045] In some embodiments, the curvature radius R1 of the object-side surface of the first lens, the curvature radius R2 of the image-side surface of the first lens, and the focal length f1 of the first lens satisfy: -6<(R1+R2) / f1<-5. Satisfying the above conditional expression, by controlling the ratio of the sum of the curvature radii of the object-side surface and the image-side surface of the first lens to the effective focal length of the first lens, the problem of increased tolerance sensitivity of the optical lens caused by excessive concentration of optical power and excessive surface bending can be avoided.

[0046] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 3<f2 / f<11. Satisfying the above conditional expression, by arranging the second lens with positive optical power and limiting the ratio of the focal length of the second lens to the effective focal length of the optical lens, it is beneficial to adjust the trend of light rays from the first lens, so that the optical lens has the characteristics of a certain large field of view, low sensitivity and miniaturization.

[0047] 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: 2<R3 / f<4.5. Satisfying the above conditional expression, such arrangement makes the object-side surface of the second lens a convex surface, so that the light rays passing through the first lens are converged into the second lens, which can reduce the size of the subsequent lenses, contribute 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.

[0048] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.1<f3 / f<4.8. Satisfying the above conditional expression enables the third lens to converge light rays, and in cooperation with the negative optical power of the first lens, can further converge the light rays passing through the second lens, lower the height of peripheral light rays, facilitate the reduction of the aperture of the rear-end lens, and at the same time facilitate aberration balancing and improve resolution.

[0049] 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: -2.8<R5 / f<-1.7. Satisfying the above conditional expression is beneficial to keeping the surface profile of the third lens within a reasonable range, and effectively balancing the aberrations generated by the first lens and the second lens, so that the optical lens has good imaging quality.

[0050] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.9<f5 / f<1.9. Satisfying the above conditional expression, in cooperation with the fourth lens, further restricts the trend of light rays, and is beneficial to correcting the aberrations generated by the refraction of light rays by the previous lenses, so as to ensure the imaging quality.

[0051] In some embodiments, the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: 0.3<(R9+R10) / (R9-R10)<0.6. By satisfying the above conditional expression and designing the fifth lens as a biconvex type, the incident angle can be reasonably increased to meet the image height requirement of the optical lens, while reducing the sensitivity of the optical lens and improving the assembly stability.

[0052] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.4<f6 / f<-0.9. By satisfying the above conditional expression, the focal length value of the sixth lens is reasonably controlled, so that the light of a large field of view rises slowly, the parallel light trend of the light beam changes to a divergent trend, which is beneficial to controlling the back focal length of the lens, realizing a large target surface and reducing the chief ray incident angle.

[0053] In some embodiments, the curvature radius R11 of the object side of the sixth lens and the curvature radius R12 of the image side of the sixth lens satisfy: -1.1<(R11+R12) / (R11-R12)<-0.8. By satisfying the above conditional expression, the off-axis aberration of the optical lens can be corrected, the generation of astigmatism can be suppressed, the angle at which the chief ray of the peripheral field of view is incident on the image plane can be controlled, and the resolving power of the optical lens can be improved.

[0054] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -195<f7 / f<-30. By satisfying the above conditional expression, the ratio of the curvature radius of the image side of the seventh lens to the effective focal length is controlled to adjust the light divergence angle and increase the image plane height.

[0055] In some embodiments, the curvature radius R14 of the image side of the seventh lens and the effective focal length f of the optical lens satisfy: 3<R14 / f<16. By satisfying the above conditional expression, the surface shape of the image side of the seventh lens is controlled, which effectively corrects the spherical aberration of the optical lens, reduces the influence of astigmatism on the imaging of the optical lens, and in addition, can adjust the trend of light, so that the optical lens has a large field of view angle and an ultra-thin profile.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 0.7<f8 / f<1.2. By satisfying the above conditional expression, the eighth lens is defined to have positive refractive power, which is beneficial to light convergence, so that chromatic aberration can be effectively corrected; meanwhile, as the last lens, the eighth lens can perform final correction on the aberration generated by the eccentricity error of each lens on the object side, that is, the eccentricity sensitivity of the optical lens can be reduced, the astigmatism generated by the eccentricity of each lens on the object side can be suppressed, so as to realize the correction of the aberration of the optical lens and improve the imaging resolution.

[0057] In some embodiments, the clear semi-aperture CSD21 of the object-side surface of the second lens and the sagittal height SAG21 of the clear semi-aperture of the object-side surface of the second lens satisfy: 7<CSD21 / SAG21<12. Satisfying the above conditional expression can effectively control the size of the clear semi-aperture of the object-side surface of the second lens, so as to cooperatively control the sagittal height at the maximum clear semi-aperture of the object-side surface of the second lens, which can compress the volume of the optical lens to a greater extent and reduce the risk of ghost images.

[0058] In some embodiments, the maximum field of view FOV of the optical lens and the chief ray incident angle CRA at the maximum image height of the optical lens satisfy: 5<FOV / CRA<11. Satisfying the above conditional expression enables incident light rays of different field of view angles of the optical lens to enter the image sensor at a suitable angle, thereby improving the photosensitive performance of the image sensor and enhancing the imaging quality of the optical lens.

[0059] In some embodiments, the spacing CT12 on the optical axis between the first lens and the second lens and the effective focal length f of the optical lens satisfy: 0.4<CT12 / f<0.9. By satisfying the above conditional expression and controlling the relationship between the distance on the optical axis from the image-side surface of the first lens to the object-side surface of the second lens and the effective focal length of the optical lens, it is beneficial to limit the size of the light beam incident into the optical lens to further improve the imaging quality; at the same time, it is also beneficial to shorten the total length of the lens and realize the miniaturization of the lens.

[0060] In some embodiments, the focal length f8 of the eighth lens and the sagittal height SAG82 of the clear semi-aperture of the image-side surface of the eighth lens satisfy: -2.8<f8 / SAG82<-0.9. The optical power and lens shape of the eighth lens can be reasonably configured to minimize chromatic aberration and spherical aberration and improve the imaging quality of the optical lens. Meanwhile, by constraining the focal length and sagittal height of the eighth lens, it is beneficial to compress the size of the optical lens to meet the design requirements for miniaturization of the optical lens.

[0061] In some embodiments, the curvature radius R3 of the object-side surface of the second lens and the center thickness CT2 of the second lens satisfy: 5<R3 / CT2<8. Satisfying the above conditional expression makes the surface profile of the object-side surface of the second lens tend to be smooth, which can effectively reduce the angular deviation of light rays incident on the second lens under different fields of view, thereby reducing the deflection sensitivity of the second lens to light rays. In addition, it can also constrain the thickness of the second lens, which is beneficial to realize the lightweight design of the optical lens.

[0062] In some embodiments, the optical lens satisfies the conditional expressions: 2.1mm<f<2.8mm; 18mm<TTL<22mm; 155°<FOV<175°; 1.4mm<EPD<1.9mm; 1.45<Fno<1.55; 14°<CRA<30°; 9mm<IH<11mm, where f denotes the effective focal length of the optical lens, TTL denotes the total optical length of the optical lens, FOV denotes the maximum field of view of the optical lens, EPD denotes the entrance pupil diameter of the optical lens, Fno denotes the f-number of the optical lens, CRA denotes the chief ray incident angle at the maximum image height of the optical lens, and IH denotes 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 height, low distortion, and low sensitivity.

[0063] In some embodiments, all eight lenses in the optical lens may be made of plastic lenses, or adopt a hybrid glass-plastic material matching structure. Preferably, the optical lens of the present invention adopts an eight-lens hybrid glass-plastic matching lens structure, which enables the optical lens to better match a large-target-surface chip to achieve high-definition imaging, and at the same time can achieve a reasonable balance of miniaturization, large image plane and large field of view of the optical lens. Specifically, the first lens may be a glass lens, and the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are all plastic lenses; adopting the hybrid glass-plastic structure can improve the thermal stability of the optical lens, reduce aberrations and distortion, and make the imaging of the optical lens clearer and sharper.

[0064] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens may be spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens of the present invention adopts a spherical lens, and the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens can all adopt aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens.

[0065] In various embodiments of the present invention, when the lenses are aspherical lenses, the shape of each aspherical surface of the optical lens satisfies the following equation: ; 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.

[0066] 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.

[0067] Example 1

[0068] Please see Figure 1 The diagram shown is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens includes, in sequence along the optical axis from the object side to the imaging plane: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0069] 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 positive 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 concave, and its image side S6 is convex. The fourth lens L4 has negative 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 negative optical power, its object side S13 is convex, and its image side S14 is concave. The eighth lens L8 has positive optical power, its object side S15 is convex, and its image side S16 is convex. The object-side surface S17 and the image-side surface S18 of filter G1 are both planar. The imaging plane S19 is a plane.

[0070] The first lens L1 is a glass spherical lens, while the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are all plastic aspherical lenses.

[0071] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0072] Table 1-1

[0073] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0074] Table 1-2

[0075] In this embodiment, the astigmatism curve, axial chromatic aberration curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 As shown.

[0076] Figure 2 The diagram shows the astigmatism curve of the optical lens 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 to 0.15 mm, indicating that the optical lens can effectively correct astigmatism.

[0077] Figure 3 The diagram shows the axial aberration curve of the optical lens 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 ±0.02 mm, indicating that the optical lens can effectively correct axial aberration.

[0078] Figure 4 The diagram shows the transverse chromatic aberration curve of the optical lens 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 figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±6 μm, indicating that the optical lens can effectively correct transverse chromatic aberration.

[0079] Example 2

[0080] Please see Figure 5The 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 fourth lens L4 has positive optical power; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0081] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0082] Table 2-1

[0083] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0084] Table 2-2

[0085] In this embodiment, the astigmatism curve, axial chromatic aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0086] from Figure 6 As can be seen, the astigmatism of the meridional and sagittal image planes is controlled within ±0.1mm, indicating that the optical lens can effectively correct astigmatism.

[0087] from Figure 7 As can be seen, the axial aberration offset is controlled within -0.03mm to 0.02mm, indicating that the optical lens can effectively correct axial aberration.

[0088] from Figure 8 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±4μm, indicating that the optical lens can effectively correct transverse chromatic aberration.

[0089] Example 3

[0090] 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 fourth lens L4 has positive optical power; the object side surface S15 of the eighth lens L8 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0091] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0092] Table 3-1

[0093] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0094] Table 3-2

[0095] In this embodiment, the astigmatism curve, axial chromatic aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown.

[0096] from Figure 10 As can be seen, the astigmatism of the meridional and sagittal image planes is controlled within -0.15mm to 0.1mm, indicating that the optical lens can effectively correct astigmatism.

[0097] from Figure 11 As can be seen, the axial aberration offset is controlled within -0.04mm to 0, indicating that the optical lens can effectively correct axial aberration.

[0098] from Figure 12 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±5μm, indicating that the optical lens can effectively correct transverse chromatic aberration.

[0099] 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 numerical value corresponding to each conditional expression in each embodiment.

[0100] Table 4

[0101] 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 a large field of view, miniaturization, large aperture, large image plane, and high imaging quality.

[0102] 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.

[0103] 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 components are sequentially arranged as follows: a first lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; a second lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; a third lens with positive optical power, wherein the object side surface thereof is a concave surface, and the image side surface thereof is a convex surface; a fourth lens with optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; a fifth lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface; a sixth lens with negative optical power, wherein the object side surface thereof is a concave surface, and the image side surface thereof is a concave surface; a seventh lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; an eighth lens with positive optical power, wherein the image side surface thereof is a convex surface; wherein the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6.5<TTL / f<9.5; the maximum field of view FOV of the optical lens and the f-number Fno of the optical lens satisfy: 100°<FOV / Fno<115°.

2. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the f-number Fno of the optical lens satisfy: 1.3mm<f / Fno<1.9mm.

3. The optical lens according to claim 1, characterized in that, The clear semi-aperture CSD11 of the object side surface of the first lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.4<CSD11 / IH<0.

9.

4. The optical lens according to claim 1, characterized in that, 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: 1.5<f45678 / f<2.

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 f1 of the first lens satisfy: -1.7<f1 / f<-1.4; the curvature radius R1 of the object side surface of the first lens, the curvature radius R2 of the image side surface of the first lens and the focal length f1 of the first lens satisfy: -6<(R1+R2) / f1<-5.

6. 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: 3<f2 / f<11; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 2<R3 / f<4.

5.

7. 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: 4.1<f3 / f<4.8; the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: -2.8<R5 / f<-1.

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 f5 of the fifth lens satisfy: 0.9<f5 / f<1.9; 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: 0.3<(R9+R10) / (R9-R10)<0.

6.

9. 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: -2.4<f6 / f<-0.9; the curvature radius R11 of the object side of the sixth lens and the curvature radius R12 of the image side of the sixth lens satisfy: -1.1<(R11+R12) / (R11-R12)<-0.

8.

10. 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: -195<f7 / f<-30; the curvature radius R14 of the image side of the seventh lens and the effective focal length f of the optical lens satisfy: 3<R14 / f<16.

11. 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: 0.7<f8 / f<1.2.

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