Optical lens

Abstract

The present invention provides an optical lens, which includes, from the object side to the imaging surface along the optical axis, a first lens with positive optical power, whose object side surface is convex and whose image side surface is concave; a second lens with negative optical power, whose object side surface is convex and whose image side surface is concave; a third lens with positive optical power; a fourth lens with positive optical power, whose object side surface is convex at the near optical axis and whose image side surface is concave at the near optical axis; a fifth lens with positive optical power, whose object side surface is concave; whose image side surface is convex; a sixth lens with positive optical power, whose object side surface is convex at the near optical axis and whose image side surface is concave at the near optical axis; a seventh lens with negative optical power, whose object side surface is concave; an eighth lens with negative optical power, whose object side surface is concave and whose image side surface is concave at the near optical axis. The optical lens provided by the present invention can improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens.

Description

Technical Field

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

[0002] With the rapid development of the performance and technology of electronic products, people have higher and higher requirements for the shooting function of portable electronic products. Currently, the main camera of mainstream mobile phone lenses uses a target surface smaller than 1 / 1.5 inches. Due to the constraints of pixels and pixel points, it is impossible to meet the requirements of both high pixels and large pixel points at the same time. Insufficient light sensitivity when taking pictures in a relatively dark environment will bring a lot of noise to the image quality, resulting in a decline in image quality and unclear imaging. Summary of the Invention

[0003] In view of the above problems, the purpose of the present invention is to provide an optical lens, which adopts a large aperture and a 1 / 1.3-inch large target surface design, can be compatible with high pixels and large pixel points, and has the advantages of excellent imaging quality.

[0004] The technical solution adopted by the present invention is as follows:

[0005] An optical lens is composed of eight lenses, and successively includes from the object side to the imaging surface along the optical axis:

[0006] A first lens with positive optical power, its object side is convex, and its image side is concave;

[0007] A second lens with negative optical power, its object side is convex, and its image side is concave;

[0008] A third lens with positive optical power;

[0009] A fourth lens with positive optical power, its object side is convex near the optical axis, and its image side is concave near the optical axis;

[0010] A fifth lens with positive optical power, its object side is concave; its image side is convex;

[0011] A sixth lens with positive optical power, its object side is convex near the optical axis, and its image side is concave near the optical axis;

[0012] A seventh lens with negative optical power, its object side is concave;

[0013] An eighth lens with negative optical power, its object side is concave, and its image side is concave near the optical axis;

[0014] Wherein, the true image height IH corresponding to the maximum field of view angle of the optical lens satisfies: 12mm < IH < 13.5mm; the true image height IH corresponding to the maximum field of view angle of the optical lens and the aperture value Fno of the optical lens satisfy: 6.5mm < IH / Fno < 8mm.

[0015] More preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 0.5 < f1 / f < 1; the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -2.5 < f2 / f < -1.5.

[0016] More preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 7.5 < f3 / f < 25.

[0017] More preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 5 < f4 / f < 20; the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.5 < f5 / f < 3.

[0018] More preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 2 < f6 / f < 24.

[0019] More preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -1.5 < f7 / f < -0.5; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.8 < R13 / f < -0.15.

[0020] More preferably, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -1.8 < f8 / f < -1.

[0021] More preferably, the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < R11 / f < 10; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: 2 < R12 / f < 20.

[0022] More preferably, the focal length f1 of the first lens and the focal length f8 of the eighth lens satisfy: -1 < f1 / f8 < -0.3.

[0023] More preferably, the central thickness CT4 of the fourth lens and the central thickness CT5 of the fifth lens satisfy: 0.3 < CT4 / CT5 < 0.9; the central thickness CT4 of the fourth lens and the air gap CT45 between the fourth lens and the fifth lens along the optical axis satisfy: 0.25 < CT4 / CT45 < 0.6.

[0024] More preferably, the effective aperture DM11 of the object side of the first lens and the effective aperture DM82 of the image side of the eighth lens satisfy: 0.3 < DM11 / DM82 < 0.45.

[0025] Compared with the prior art, the optical lens provided by the present invention adopts eight lenses with specific optical focal lengths. Through specific surface shape matching and reasonable optical focal length distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages such as large target surface, large aperture, miniaturization, and high pixels. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0028] Figure 2 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 1 of the present invention.

[0029] Figure 3 It is a field curvature curve diagram of the optical lens in Example 1 of the present invention.

[0030] Figure 4 Graph showing the vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0031] Figure 5 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0032] Figure 6 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 2 of the present invention.

[0033] Figure 7 4 is a field curvature curve diagram of the optical lens in Example 2 of the present invention.

[0034] Figure 8 Graph showing the vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0035] Fig. 9 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0036] Fig.10 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 3 of the present invention.

[0037] Fig.11 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0038] Fig.12 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0039] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0040] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application, and are not intended to limit the scope of the present 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.

[0041] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0042] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0043] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface 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 object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0044] It should also be understood that the terms "comprises", "including", "having", "includes" 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. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0045] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0046] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] The optical lens provided by the embodiment of the present invention is composed of eight lenses, which are 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 in order from the object side to the imaging surface along the optical axis.

[0048] In some embodiments, the first lens may have positive optical power, its object side surface is convex, and its image side surface is concave. The second lens may have negative optical power, its object side surface is convex, and its image side surface is concave. The third lens may have positive optical power, its object side surface may be concave or convex, and its image side surface may be concave or convex. The fourth lens may have positive optical power, its object side surface is convex at the near optical axis, and its image side surface is concave at the near optical axis. The fifth lens may have positive optical power, its object side surface is concave; its image side surface is convex. The sixth lens may have positive optical power, its object side surface is convex at the near optical axis, and its image side surface is concave at the near optical axis. The seventh lens may have negative optical power, its object side surface is concave, and its image side surface may be concave or convex. The eighth lens may have negative optical power, its object side surface is concave, and its image side surface is concave at the near optical axis.

[0049] In some embodiments, the optical lens may further include an aperture, and the aperture may be located between the object side and the first lens. It is understood that the aperture is used to limit the amount of incoming light to change the brightness of the image.

[0050] In some embodiments, the optical lens may further include a filter, which may be disposed between the eighth lens and the imaging surface. The filter is used to filter out interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0051] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens satisfies: 12 mm < IH < 13.5 mm. Meeting the above conditions indicates that the lens has a large target surface, can match an imaging chip with a large target surface (such as larger than 1 / 1.3 inch) to achieve high-definition imaging. Moreover, with the increase of the target surface, the pixel distribution can be sparser (i.e., the pixel size is larger), which can effectively reduce noise even in a relatively dark environment, and the dynamic range will be wider, and more details can be retained in the dark part, so as to present a clearer shooting effect.

[0052] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the aperture value Fno of the optical lens satisfy: 6.5 mm < IH / Fno < 8 mm. Meeting the above conditions can enable the lens to better achieve the balance of large target surface imaging and large aperture performance, make the pixel distribution sparser (i.e., the pixel size is larger), can reduce noise in a relatively dark environment, the dynamic range will be wider, and more details can be retained in the dark part, thereby improving the image quality.

[0053] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 0.5 < f1 / f < 1. Meeting the above conditions can make the first lens have a large positive refractive power, while improving the light collection ability of the edge field of view, reducing the working aperture of the first lens, which is beneficial to achieving the balance of large aperture and small aperture.

[0054] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -2.5 < f2 / f < -1.5. Meeting the above conditions, the second lens has a large negative refractive power, can diverge the incident light to a large extent, so as to effectively increase the height of the light entering the imaging surface and better achieve the large target surface imaging of the lens.

[0055] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 7.5 < f3 / f < 25. Meeting the above conditions can make the third lens have an appropriate positive optical power, which is beneficial to the smooth transition of the light trend, improve the imaging quality of the optical lens, and at the same time reduce the system sensitivity and improve the manufacturing yield.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 5 < f4 / f < 20. Meeting the above conditions can further effectively converge the light, reduce the difficulty of correcting the distortion of the edge field of view, ensure that the lens has a small distortion while achieving a large field of view angle, improve the overall imaging quality, and at the same time reduce the system sensitivity and improve the manufacturing yield.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.5 < f5 / f < 3. Meeting the above conditions is beneficial to balancing the astigmatism and field curvature of the optical lens and improving the imaging quality of the optical lens.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 2 < f6 / f < 24. Meeting the above conditions, by setting the sixth lens to have an appropriate positive optical power, the system sensitivity can be reduced, the manufacturing yield can be improved, and at the same time, it is beneficial to correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -1.5 < f7 / f < -0.5. Meeting the above conditions is beneficial to diverging the light in the central field of view to a certain extent, and at the same time, combining with the bending of the peripheral field of view to reduce the exit angle of the light in the peripheral field of view and improve the relative illumination of the peripheral field of view.

[0060] In some embodiments, the curvature radius R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -0.8 < R13 / f < -0.15. Meeting the above conditions can appropriately suppress the angle at which the light in the peripheral field of view enters the imaging surface, effectively transmit more light beams to the imaging surface, and improve the relative illumination of the optical lens.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -1.8 < f8 / f < -1. Meeting the above conditions is beneficial to further diverging the incident light, making the peripheral light and the central light turn up and reach a higher imaging position, better realizing the large target surface imaging of the lens and improving the imaging quality.

[0062] In some embodiments, the curvature radius R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < R11 / f < 10; the curvature radius R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 2 < R12 / f < 20. Meeting the above conditions can better converge the light at the large field of view, reduce the optical path difference between the center and the periphery of the lens, and is beneficial to correcting the distortion of the optical lens.

[0063] In some embodiments, the focal length f1 of the first lens and the focal length f8 of the eighth lens satisfy: -1 < f1 / f8 < -0.3. Meeting the above conditions is beneficial to increasing the area of the light entering the imaging surface, realizing the large target surface imaging of the lens, and improving the imaging quality of the optical lens.

[0064] In some embodiments, the central thickness CT4 of the fourth lens and the central thickness CT5 of the fifth lens satisfy: 0.3 < CT4 / CT5 < 0.9; the central thickness CT4 of the fourth lens and the air gap CT45 between the fourth lens and the fifth lens along the optical axis satisfy: 0.25 < CT4 / CT45 < 0.6. Meeting the above conditions, by reasonably setting the central thicknesses of the fourth and fifth lenses and the air gap, it is beneficial to optimize the small head size of the lens.

[0065] In some embodiments, the effective aperture DM11 of the object side of the first lens and the effective aperture DM82 of the image side of the eighth lens satisfy: 0.3 < DM11 / DM82 < 0.45. Meeting the above conditions, by reasonably setting the ratio of the apertures of the first and last lenses, the lens can have a smaller head size while having a larger imaging surface, and can better meet the balance of miniaturization and high pixels.

[0066] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.15 < TTL / f < 1.3. Meeting the above conditions can effectively limit the length of the lens and is beneficial to the miniaturization of the optical lens.

[0067] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.72 < IH / f < 1.8. Meeting the above conditions is beneficial to achieving the telephoto characteristics of the lens, facilitating the realization of a large imaging surface of the lens, and thus improving the imaging quality of the optical lens.

[0068] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.66 < TTL / IH < 0.73. Meeting the above conditions can better achieve the miniaturization of the lens while ensuring that the lens has a large imaging surface and can match a larger-sized imaging chip to achieve high-definition imaging.

[0069] In some embodiments, the curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: 0.02 < R1 / R2 < 0.2. Meeting the above conditions, the first lens adopts a convex-concave positive meniscus shape, which is beneficial to the convergence of incident light, reduces the head lens aperture, and is conducive to head miniaturization.

[0070] In some embodiments, the curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side of the second lens satisfy: 1.5 < R3 / R4 < 3. Meeting the above conditions, the second lens adopts a negative meniscus lens, which is beneficial to diverging the light incident after being converged by the first lens, making the light trend transition smoothly, and improving the imaging quality of the optical lens.

[0071] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.2 < R7 / R8 < 0.8. Meeting the above conditions is beneficial to the smooth transition of light, while correcting various aberrations of the optical lens and improving the imaging quality of the optical lens.

[0072] 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: 1 < R9 / R10 < 6. Meeting the above conditions is beneficial to better achieve the convergence of light, shorten the distance for light to reach the next lens, and is beneficial to reducing the total length of the optical lens.

[0073] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.6 < f1 / f2 < -0.2. Meeting the above conditions can diverge a wide range of light entering the system to a certain extent, increase the height of the light entering the imaging surface while increasing the field of view angle, thereby achieving the balance of wide-angle and high-pixel of the optical lens.

[0074] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: 0.3 < f3 / f4 < 4. Meeting the above conditions is beneficial to the smooth transition of light, while correcting various aberrations of the optical lens and improving the imaging quality of the optical lens.

[0075] In some embodiments, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: 0.01 < f5 / f6 < 1. Meeting the above conditions is beneficial to the smooth transition of light, while correcting various aberrations of the optical lens and improving the imaging quality of the optical lens.

[0076] In some embodiments, the focal length f7 of the seventh lens and the focal length f8 of the eighth lens satisfy: 0.2 < f7 / f8 < 1.2. Meeting the above conditions, by reasonably setting the focal length relationship between the seventh and eighth lenses, the light can be diverged to a large extent and the aberration can be effectively corrected, which is beneficial to achieving large target surface imaging of the lens.

[0077] In some embodiments, the optical lens satisfies the conditional formula: 6.5mm < f < 8mm, 78° < FOV < 85°, 8mm < TTL < 9.5mm, 1.6 < Fno < 1.8, 35° < CRA < 40°; where f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, and CRA represents the chief ray angle of incidence at the maximum image height of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least a relatively large aperture value, enabling high-definition imaging even in a relatively dark environment; having a relatively large CRA, it can well match a large CRA imaging chip and better achieve large target surface imaging of the lens.

[0078] 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, the production cost can be effectively reduced. Additionally, when the lens material is glass, due to the low dispersion characteristic of the glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. The optical lens provided by the present invention can adopt an all-plastic lens structure, which not only enables the lens to have excellent imaging performance, but also makes the structure of the lens relatively compact, and can better achieve the balance of miniaturization and high image quality of the lens.

[0079] 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 can adopt 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 achieving the miniaturization of the lens. More specifically, 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 of the present invention 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 achieving the miniaturization of the lens.

[0080] In various embodiments of the present invention, when the lens adopts an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0081] ;

[0082] where z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and B, C, D, E, F, G, H are the surface coefficients of the fourth order, sixth order, eighth order, tenth order, twelfth order, fourteenth order, and sixteenth order respectively.

[0083] The present invention is further described below in multiple 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 table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0084] Example 1

[0085] See also Figure 1 , shown is a schematic diagram of the structure of the optical lens 100 provided in Example 1 of the present invention, and the optical lens includes, along the optical axis from the object side to the imaging surface, an aperture ST, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens and a filter G1.

[0086] The first lens L1 has positive refractive power, its object side surface S1 is convex, and its image side surface S2 is concave;

[0087] The second lens L2 has negative refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0088] The third lens L3 has positive refractive power, an object-side surface S5 thereof is convex at the near optical axis, and an image-side surface S6 thereof is concave at the near optical axis;

[0089] The fourth lens L4 has positive refractive power, an object-side surface S7 thereof is convex at the near optical axis, and an image-side surface S8 thereof is concave at the near optical axis;

[0090] The fifth lens L5 has positive refractive power, its object-side surface S9 is concave, and its image-side surface S10 is convex;

[0091] The sixth lens L6 has positive refractive power, an object-side surface S11 thereof is convex at the near optical axis, and an image-side surface S12 thereof is concave at the near optical axis;

[0092] The seventh lens L7 has negative refractive power, its object-side surface S13 is concave, and its image-side surface S14 is convex;

[0093] The eighth lens L8 has negative refractive power, its object-side surface S15 is concave, and its image-side surface S16 is concave near the optical axis;

[0094] The object side surface S17 and the image side surface S18 of the filter G1 are both planes;

[0095] The imaging surface S19 is a plane.

[0096] The first lens L1, 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.

[0097] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0098] Table 1-1

[0099]

[0100] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0101] Table 1-2

[0102]

[0103] Figure 2 The F-Tan (Theta) distortion curve of the optical lens 100 in this embodiment is shown, which represents the distortion of different field angles on the imaging plane, with the horizontal axis representing the distortion value (unit: %) and the vertical axis representing the half field angle (unit: °). It can be seen from the figure that the distortion value is controlled within ±2%, indicating that the optical lens 100 can correct the distortion well.

[0104] Figure 3 The field curvature curve of the optical lens 100 in this embodiment is shown, which indicates the degree of curvature of light in the meridional image plane and the sagittal image plane, the horizontal axis indicates the offset (unit: mm), and the vertical axis indicates the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens 100 can correct the field curvature well.

[0105] Figure 4 The vertical axis chromatic aberration curve of the optical lens 100 in this embodiment is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.555 μm) at different image heights on the imaging surface, the horizontal axis represents the vertical axis chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1 μm, indicating that the optical lens 100 can correct the chromatic aberration well.

[0106] Example 2

[0107] See also Figure 5, shown is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main differences of this embodiment are: the object-side surface S5 of the third lens L3 is a concave surface; the image-side surface S6 of the third lens L3 is a convex surface; the image-side surface S14 of the seventh lens L7 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0108] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0109] Table 2-1

[0110]

[0111] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0112] Table 2-2

[0113]

[0114] In this embodiment, the F-Tan (Theta) distortion curve, the field curvature curve, and the vertical axis chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 shown.

[0115] from Figure 6 It can be seen that the distortion value is controlled within ±2%, indicating that the optical lens 200 can correct the distortion well.

[0116] from Figure 7 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens 200 can correct the field curvature well.

[0117] from Figure 8 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0118] Example 3

[0119] See also Fig. 9 , shown is a schematic diagram of the structure of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main differences of this embodiment are: the object side surface S5 of the third lens L3 is a concave surface; the image side surface S6 of the third lens L3 is a convex surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0120] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0121] Table 3-1

[0122]

[0123] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0124] Table 3-2

[0125]

[0126] In this embodiment, the F-Tan (Theta) distortion curve, the field curvature curve, and the vertical axis chromatic aberration curve of the optical lens 300 are shown in FIG. Fig.10 , Fig.11 , Fig.12 shown.

[0127] from Fig.10 It can be seen that the distortion value is controlled within ±2%, indicating that the optical lens 300 can correct the distortion well.

[0128] from Fig.11 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens 300 can correct the field curvature well.

[0129] from Fig.12 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1 μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0130] Please refer to Table 4, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the chief ray incident angle CRA at the maximum image height, the maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0131] Table 4

[0132]

[0133] In summary, the optical lens provided by the present invention has at least the following advantages:

[0134] (1) Through specific surface shape settings and reasonable optical focal length distribution, the overall length of the optical lens can be effectively shortened, which is conducive to better miniaturization of the optical lens; at the same time, it has a large aperture and can achieve high-definition imaging even in dim environments.

[0135] (2) The large target surface characteristic of the lens is realized, and it can match the imaging chip with a larger target surface (such as larger than 1 / 1.3 inches) to achieve high-definition imaging. In addition, the increase in the target surface can make the pixel distribution more sparse (that is, the pixel size is larger), which can effectively reduce noise even in darker environments, and the dynamic range will be wider. More details can be retained in the dark area, thus presenting a clearer shooting effect. At the same time, it can also reasonably correct the overall aberration of the optical lens, so that the optical lens has high pixels and improves the imaging quality of the optical lens.

[0136] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0137] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, consisting of eight lenses, characterized in that: From the object side to the imaging plane along the optical axis, it successively includes: A first lens with positive optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose object side is convex and whose image side is concave; A third lens with positive optical power; A fourth lens with positive optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; A fifth lens with positive optical power, whose object side is concave; whose image side is convex; A sixth lens with positive optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; A seventh lens with negative optical power, whose object side is concave; An eighth lens with negative optical power, whose object side is concave and whose image side is concave near the optical axis; Wherein, the true image height IH corresponding to the maximum field of view angle of the optical lens satisfies: 12mm < IH < 13.5mm; the true image height IH corresponding to the maximum field of view angle of the optical lens and the aperture value Fno of the optical lens satisfy: 6.5mm < IH / Fno < 8mm.

2. 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: 0.5 < f1 / f < 1; the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -2.5 < f2 / f < -1.

5.

3. 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: 7.5 < f3 / f < 25.

4. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 5 < f4 / f < 20; the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.5 < f5 / f < 3.

5. 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 < f6 / f < 24.

6. 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: -1.5 < f7 / f < -0.5; the curvature radius R13 of the object side of the seventh lens and the effective focal length f of the optical lens satisfy: -0.8 < R13 / f < -0.

15.

7. 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: -1.8 < f8 / f < -1.

8. The optical lens according to claim 1, characterized in that: The curvature radius R11 of the object side of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < R11 / f < 10; the curvature radius R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: 2 < R12 / f < 20.

9. The optical lens according to claim 1, characterized in that: The focal length f1 of the first lens and the focal length f8 of the eighth lens satisfy: -1 < f1 / f8 < -0.

3.

10. The optical lens according to claim 1, characterized in that: The central thickness CT4 of the fourth lens and the central thickness CT5 of the fifth lens satisfy: 0.3 < CT4 / CT5 < 0.9; the central thickness CT4 of the fourth lens and the air gap CT45 between the fourth lens and the fifth lens along the optical axis satisfy: 0.25 < CT4 / CT45 < 0.

6.

11. The optical lens according to claim 1, characterized in that: The effective aperture DM11 of the object side of the first lens and the effective aperture DM82 of the image side of the eighth lens satisfy: 0.3 < DM11 / DM82 < 0.45.

Images