Optical lens

Abstract

The application provides an optical lens, which comprises eight lenses in sequence along an optical axis from an object side to an imaging surface, and the eight lenses comprise: a first lens with negative optical power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative optical power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; a third lens with positive optical power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; a fourth lens with negative optical power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a concave surface; a fifth lens with positive optical power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; a sixth lens with positive optical power, the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface; a seventh lens with negative optical power, the object side surface of the seventh lens is a concave surface; and an eighth lens with positive optical power. The optical lens provided by the application has one or more advantages of miniaturization, large wide angle, large aperture, high imaging quality and the like through specific surface shape matching and reasonable optical power distribution.

Description

Technical Field

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

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

[0003] To address the aforementioned problems, the present invention aims to provide an optical lens that has the advantages of miniaturization and excellent imaging quality.

[0004] This invention provides an optical lens comprising eight lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0005] The first lens with negative optical power has a convex object side and a concave image side.

[0006] A second lens with negative optical power has a convex object side and a concave image side.

[0007] A third lens with positive optical power has a convex object-side surface and a concave image-side surface.

[0008] The fourth lens with negative optical power has a convex object side and a concave image side.

[0009] The fifth lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0010] The sixth lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0011] The seventh lens has negative optical power and its object side is concave.

[0012] The eighth lens, which has positive optical power, has a convex object-side surface;

[0013] Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 12.5 <TTL / f<12.9。

[0014] Further preferably, the true 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: 3.1 <IH / f<3.4。

[0015] Further preferably, the focal length f1 of the first lens, the object-side radius of curvature R1 of the first lens, and the image-side radius of curvature R2 of the first lens satisfy: -1.8 <f1 / (R1+R2)<-1.5。

[0016] Further preferably, the half-aperture CSD11 of the object-side surface of the first lens and the distance CT12 between the first lens and the second lens on the optical axis satisfy: 8.5 <CSD11 / CT12<18.5。

[0017] Further preferably, the half-aperture CSD11 of the object-side surface of the first lens and the half-aperture CSD81 of the object-side surface of the eighth lens satisfy: 3.7 <CSD11 / CSD81<3.9。

[0018] Further preferably, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens satisfies -1.7 with the effective focal length f of the optical lens. <f1234 / f<-1.35。

[0019] Further preferably, the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfies the following condition with respect to the effective focal length f of the optical lens: 1.6 <f5678 / f<1.8。

[0020] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -25 <f1 / f<-23。

[0021] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.6 <f2 / f<-2.1。

[0022] Further preferably, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: 3.6 <f8 / f<4.7。

[0023] Compared with existing technologies, the optical lens provided by this invention uses eight lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as miniaturization, wide angle, large aperture, and high imaging quality. Attached Figure Description

[0024] 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:

[0025] Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0026] Figure 2 This is an astigmatism curve diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 5 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0030] Figure 6 This is an astigmatism curve of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 7 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 8 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 9 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0034] Figure 10 This is an astigmatism curve diagram of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 11 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 12 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0037] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The optical lens provided by the embodiment of the present invention has a total of eight lenses. The optical lens sequentially includes, along the optical axis from the object side to the imaging surface: 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.

[0046] In some embodiments, the first lens may have a negative optical power, its object side is convex, and its image side is concave. The second lens may have a negative optical power, its object side is convex, and its image side is concave. The third lens may have a positive optical power, its object side is convex, and its image side is concave. The fourth lens may have a negative optical power, its object side is convex, and its image side is concave. The fifth lens may have a positive optical power, its object side is convex, and its image side is convex. The sixth lens may have a positive optical power, its object side is convex, and its image side is convex. The seventh lens may have a negative optical power, its object side is concave, and its image side may be concave or convex. The eighth lens may have a positive optical power, its object side is convex, and its image side may be concave or convex.

[0047] In some embodiments, the optical lens may further include an aperture, and the aperture may be located between the fourth lens and the fifth lens. It can be understood that the aperture is used to limit the amount of incident light to change the brightness of the image. When the aperture is located between the fourth lens and the fifth lens, it is convenient for the correction of aperture aberration.

[0048] In some embodiments, the optical lens may further include a filter, and the filter is disposed between the eighth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0049] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 12.5 < TTL / f < 12.9. Satisfying the above conditional formula can reasonably configure the ratio of the total optical length to the effective focal length of the optical lens, which is beneficial to the miniaturized design of the optical lens. At the same time, it is also beneficial for the optical lens to have a reasonable field angle range while achieving a certain focal length characteristic, so as to meet the wide-angle design of the optical lens and enable the optical lens to obtain sufficient object-side space information.

[0050] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 3.1 < IH / f < 3.4. Satisfying the above conditional formula, controlling the ratio of the effective focal length to the image height of the optical lens, shortening the effective focal length can expand the field angle, enabling the optical lens to capture a wider object-side space, and at the same time enabling the optical lens to match a large-image-plane chip to improve the imaging quality of the optical lens.

[0051] In some embodiments, the focal length f1 of the first lens, the radius of curvature R1 of the object side surface of the first lens, and the radius of curvature R2 of the image side surface of the first lens satisfy: -1.8 < f1 / (R1 + R2) < -1.5. Satisfying the above conditional formula can constrain the surface profiles of the object side surface and the image side surface of the first lens, which is beneficial to reducing the bending degree of light rays at the image side surface of the first lens, reducing the astigmatism amount of the optical lens, so as to balance the astigmatism problem brought by the large field angle of the optical lens, and enabling the astigmatism of the optical lens not to be too large while having a large field of view, thereby ensuring that the optical lens has excellent imaging quality.

[0052] In some embodiments, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the spacing CT12 between the first lens and the second lens on the optical axis satisfy: 8.5 < CSD11 / CT12 < 18.5. Satisfying the above conditional formula, by controlling the clear aperture of the object side surface of the first lens and reducing the air gap between the first lens and the second lens, it is beneficial to reduce the total length of the optical lens, make the arrangement of the optical lens more compact, and reduce the risk of ghost image generation; furthermore, it is also beneficial to reduce the difficulty of the structural arrangement of the optical lens and improve the assembly molding yield of the optical lens.

[0053] In some embodiments, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the clear aperture semi-diameter CSD81 of the object side surface of the eighth lens satisfy: 3.7 < CSD11 / CSD81 < 3.9. Satisfying the above conditional formula, by controlling the ratio of the clear aperture semi-diameter of the object side end of the first lens and the clear aperture semi-diameter 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 a drone device; at the same time, it ensures that the optical lens can collect light rays at a large angle, realize large-field-angle imaging of the optical lens, increase the imaging area of the optical lens, and improve the imaging quality.

[0054] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the effective focal length f of the optical lens satisfy: -1.7 < f1234 / f < -1.35. Satisfying the above conditional formula, the front lens group composed of the first lens to the fourth lens provides negative optical power for the optical lens, which is beneficial to large-angle light beams passing through and entering the aperture stop of the optical lens, so as to achieve the ultra-wide-angleization of the optical lens, and at the same time improve the image plane brightness of the large-angle field of view of the optical lens.

[0055] In some embodiments, the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens, and the eighth lens and the effective focal length f of the optical lens satisfy: 1.6 < f5678 / f < 1.8. Meeting the above conditional formula, the rear lens group of the combination of the fifth lens to the eighth lens has a positive optical power, which is beneficial to correcting the chromatic aberration and field curvature of the optical lens, reducing the light deflection angle, lowering the sensitivity, reducing the lens molding difficulty, and achieving the balance of the overall spherical aberration to obtain good imaging quality of the on-axis field of view.

[0056] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -25 < f1 / f < -23. Meeting the above conditional formula, the first lens has a negative optical power, which can diverge the light passing through it, expand the field angle of the optical lens, and simplify the aberration correction and the balance of imaging quality of the overall optical lens.

[0057] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.6 < f2 / f < -2.1. Meeting the above conditional formula, setting the second lens to have a negative optical power can further control the incident angle of light, expand the field angle range of the optical lens, increase the back focal length of the optical lens at the same time, avoid interference between the lens and the photosensitive chip, and is also beneficial to the correction of aberration, and can further improve the imaging quality of the optical lens.

[0058] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: 3.6 < f8 / f < 4.7. Meeting the above conditional formula, it is defined that the eighth lens has a positive optical power, which is beneficial to light convergence, so that chromatic aberration can be effectively corrected. At the same time, as the last lens, the eighth lens can finally correct the aberration generated by the decentration difference of each lens on the object side, that is, it can reduce the decentration sensitivity of the optical lens, suppress the astigmatism generated by the decentration of each lens on the object side, and thus realize the correction of the aberration of the optical lens and improve the imaging resolution.

[0059] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 18 < f3 / f < 29. Meeting the above conditional formula, the third lens has the function of converging light. When combined with the negative optical powers of the first lens and the second lens, it can further converge the light passing through the second lens, reduce the peripheral light height, which is beneficial to the reduction of the rear lens aperture, and is also beneficial to balancing the aberration and improving the resolution.

[0060] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -3.2 < f7 / f < -2.3. By satisfying the above conditional formula, it is defined that the seventh lens has an appropriate negative optical power, which can diverge the light rays emitted by the sixth lens, making the light rays in the peripheral field of view show an upward trend, which is beneficial for the image points on the imaging surface to be far from the optical axis, so as to facilitate achieving the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolution of the optical lens.

[0061] In some embodiments, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 97° < FOV / Fno < 104°. By satisfying the above conditional formula, it is ensured that the optical lens meets the requirements of a super-large field angle and a large aperture, reduces the influence of off-axis aberration on the system, and enables the optical lens to have the characteristics of a large aperture, high relative illumination, and small distortion, thereby improving the imaging quality.

[0062] In some embodiments, the sagittal height SAG11 of the clear aperture radius on the object side of the first lens and the central thickness CT1 of the first lens satisfy: 1.8 < SAG11 / CT1 < 2. By satisfying the above conditional formula, controlling the ratio of the sagittal height of the object side of the first lens to the central thickness of the first lens on the optical axis can make the surface shape of the object side tend to be curved, and at the same time, a larger sagittal height is beneficial for the first lens to collect light rays in a large field of view, achieving high angular resolution at the center of the optical lens, and further improving the imaging quality in the central region.

[0063] In some embodiments, the edge thickness ET2 of the second lens and the central thickness CT2 of the second lens satisfy: 1.7 < ET2 / CT2 < 2.3. By satisfying the above conditional formula, by limiting the ratio of the edge thickness to the central thickness of the second lens, it is beneficial to reduce the molding difficulty of the second lens, ensure the manufacturability of the second lens, and improve the yield.

[0064] In some embodiments, the overall optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the eighth lens along the optical axis respectively satisfy: 1.45 < TTL / ∑CT < 1.5. By satisfying the above conditional formula, reasonably configuring the overall optical length of the optical lens and the sum of the thicknesses of each lens can effectively shorten the overall optical length of the optical lens, meet the requirements of miniaturization and lightweight design, and at the same time achieve the characteristics of high pixels, improving the imaging quality of the optical lens.

[0065] In some embodiments, the optical lens satisfies the following conditions: 0.7mm < f < 0.8mm; 145° < FOV ≤ 150°; 0.45mm < EPD < 0.55mm; 9mm < TTL < 10mm; 1.45 ≤ Fno ≤ 1.5; 2.4mm ≤ IH < 2.45mm; where f represents the effective focal length of the optical lens, FOV represents the maximum field of view of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, and IH represents the image height corresponding to the maximum field of view of the optical lens. Satisfying the above conditions, the optical lens possesses at least one or more advantages of short focal length, ultra-large field of view, large entrance pupil diameter, short total length, large aperture, large image plane, low distortion, and low sensitivity.

[0066] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, production costs can be effectively reduced. Conversely, when the lens material is glass, the low dispersion characteristic of glass itself can effectively correct geometric chromatic aberration of the optical system. The first and sixth lenses in the optical lens provided by the present invention can be made of glass, while the second, third, fourth, fifth, seventh, and eighth lenses can be made of plastic. This glass-plastic hybrid structure effectively reduces costs, corrects aberrations, reduces size, improves thermal stability, and provides a more cost-effective optical lens product.

[0067] In some embodiments, the first, second, third, fourth, fifth, sixth, seventh, and eighth lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, the first and sixth lenses of this invention are spherical lenses; the second, third, fourth, fifth, seventh, and eighth lenses are aspherical lenses.

[0068] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations:

[0069] ;

[0070] 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.

[0071] 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.

[0072] Example 1

[0073] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane S19, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0074] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0075] The second lens L2 has negative optical power, its object side S3 is convex, and its image side S4 is concave.

[0076] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is concave.

[0077] The fourth lens L4 has negative optical power, its object side S7 is convex, and its image side S8 is concave.

[0078] The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side S10 is convex.

[0079] The sixth lens L6 has positive optical power, its object side S11 is convex, and its image side S12 is convex.

[0080] The seventh lens L7 has negative optical power, its object side S13 is concave, and its image side S14 is concave.

[0081] The eighth lens L8 has positive optical power, its object side S15 is convex, and its image side S16 is concave.

[0082] The object-side surface S17 and the image-side surface S18 of filter G1 are both planar.

[0083] The imaging plane S19 is a plane.

[0084] The first lens L1 and the sixth lens L6 are glass spherical lenses; the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the seventh lens L7 and the eighth lens L8 are all plastic aspherical lenses.

[0085] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0086] Table 1-1

[0087]

[0088] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0089] Table 1-2

[0090]

[0091] In this embodiment, the astigmatism curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 As shown.

[0092] Figure 2 The diagram shows the astigmatism curve of the optical lens 100 in this embodiment, which represents the astigmatism of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the astigmatism in the meridional and sagittal image planes is controlled within -0.1 mm to 0.05 mm, indicating that the optical lens 100 can correct astigmatism well.

[0093] Figure 3 The diagram shows the axial aberration curve of the optical lens 100 in Embodiment 1, 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 ±0.01 mm, indicating that the optical lens 100 can correct axial aberration well.

[0094] Figure 4 The diagram shows the transverse chromatic aberration curve of the optical lens 100 in this embodiment. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2.5 μm, indicating that the optical lens 100 can effectively correct transverse chromatic aberration.

[0095] Example 2

[0096] Please see Figure 5 The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S14 of the seventh lens L7 is convex; 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 200 in Example 2 are shown in Table 2-1.

[0098] Table 2-1

[0099]

[0100] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0101] Table 2-2

[0102]

[0103] In this embodiment, the astigmatism curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0104] from Figure 6 As can be seen, the astigmatism of the meridional and sagittal image planes is controlled within -0.1mm to 0.05mm, indicating that the optical lens 200 can correct astigmatism well.

[0105] from Figure 7 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens 200 can correct the axial aberration well.

[0106] from Figure 8 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±3μm, indicating that the optical lens 200 can effectively correct transverse chromatic aberration.

[0107] Example 3

[0108] Please see Figure 9 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 image side surface S16 of the eighth lens L8 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0109] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0110] Table 3-1

[0111]

[0112] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0113] Table 3-2

[0114]

[0115] In this embodiment, the astigmatism curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown.

[0116] from Figure 10 As can be seen, the astigmatism of the meridional and sagittal image planes is controlled within -0.1mm to 0.05mm, indicating that the optical lens 300 can correct astigmatism well.

[0117] from Figure 11 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens 300 can correct axial aberration well.

[0118] from Figure 12 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2.5μm, indicating that the optical lens 300 can effectively correct transverse chromatic aberration.

[0119] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0120] Table 4

[0121]

[0122] In summary, the optical lens provided by the present invention adopts an eight-element glass-plastic hybrid structure. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as miniaturization, wide angle, large aperture, and high imaging quality.

[0123] 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.

[0124] 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, eight pieces of lenses in total, characterized in that, In order from the object side to the imaging plane along the optical axis, successively comprise: a first lens with negative focal 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 with negative focal 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 with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a fourth lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a fifth lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a sixth lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a seventh lens with negative focal power, the object side surface of which is a concave surface; an eighth lens with positive focal power, the object side surface of which is a convex surface; wherein the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 12.5 < TTL / f < 12.9; the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -25 < f1 / f < -23.

2. The optical lens of claim 1, wherein, the maximum field angle of the optical lens corresponds to the real image height IH of the optical lens and the effective focal length f of the optical lens satisfy: 3.1 < IH / f < 3.

4.

3. The optical lens of claim 1, wherein, the focal length f1 of the first lens, the object side surface curvature radius R1 of the first lens, and the image side surface curvature radius R2 of the first lens satisfy: -1.8 < f1 / (R1+R2) < -1.

5.

4. The optical lens of claim 1, wherein, the object side surface half light entrance radius CSD11 of the first lens and the distance CT12 of the first lens and the second lens on the optical axis satisfy: 8.5 < CSD11 / CT12 < 18.

5.

5. The optical lens of claim 1, wherein, the object side surface half light entrance radius CSD11 of the first lens and the object side surface half light entrance radius CSD81 of the eighth lens satisfy: 3.7 < CSD11 / CSD81 < 3.

9.

6. The optical lens of claim 1, wherein, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the effective focal length f of the optical lens satisfy: -1.7 < f1234 / f < -1.

35.

7. The optical lens of claim 1, wherein, the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens, and the eighth lens and the effective focal length f of the optical lens satisfy: 1.6 < f5678 / f < 1.

8.

8. The optical lens of claim 1, wherein, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 18 < f3 / f < 29.

9. The optical lens of claim 1, wherein, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.6 < f2 / f < -2.

1.

10. The optical lens of claim 1, wherein, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: 3.6 < f8 / f < 4.7.

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