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 focal power, whose object side surface is convex and whose image side surface is concave; a second lens with negative focal power, whose object side surface is convex and whose image side surface is concave; a third lens with positive focal power, whose object side surface is convex and whose image side surface is concave; a fourth lens with negative focal power, whose object side surface is concave near the optical axis and whose image side surface is concave; a fifth lens with positive focal power, whose object side surface is convex and whose image side surface is concave; a sixth lens with negative focal power; a seventh lens with negative focal power, whose object side surface is concave and whose image side surface is convex; and an eighth lens with negative focal power, whose object side surface is concave. The optical lens provided by the present invention has one or more advantages such as telephoto performance, large target surface, large aperture, and short total length.

Description

Technical Field

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

[0002] With the continuous upgrading of smartphones, consumers have higher and higher requirements for the shooting functions of mobile phones. The 35mm focal length (i.e., a full field of view of 63°) is considered a classic focal length for humanistic photography. Compared with the 24mm focal length, it is easier to highlight the subject; compared with the 50mm focal length, it has a larger shooting angle and is applicable to a wider range of scenarios. The 35mm focal length lens, with its relatively large viewing angle, can provide photographers with a rich ability to capture scenes, especially suitable for shooting full-body portraits; when shooting portraits, the subject can be naturally integrated into the surrounding environment, showing a more vivid and story-rich picture.

[0003] However, few smartphones on the market are equipped with 35mm focal length main cameras, partly because it is more difficult to make the aperture and image height of this focal length lens larger than that of 24mm focal length lens, and it is also difficult to make the total length very short. Therefore, how to make the mobile phone have the characteristics of large aperture, large target area, short total length, etc. while meeting the requirements of telephoto performance while ensuring high imaging quality, and how to make the optical system meet the requirements of telephoto performance is an urgent problem to be solved. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having one or more advantages such as long-focus performance, large target surface, large aperture, and short total length.

[0005] The technical solution adopted by the present invention is:

[0006] An optical lens, composed of eight lenses, including:

[0007] The first lens has positive refractive power, its object side surface is convex, and its image side surface is concave;

[0008] The second lens has a negative optical power, its object side surface is convex, and its image side surface is concave;

[0009] The third lens has positive refractive power, its object side surface is convex, and its image side surface is concave;

[0010] The fourth lens element has a negative optical power, the object side surface of which is concave at the near optical axis, and the image side surface of which is concave;

[0011] a fifth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is concave;

[0012] a sixth lens having negative optical power;

[0013] a seventh lens element having negative optical power, whose object side surface is concave and whose image side surface is convex;

[0014] an eighth lens having negative optical power, whose object side surface is concave;

[0015] Wherein, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: <f×(43.27 / IH)<35。

[0016] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 0.92 <TTL / f<1。

[0017] Further preferably, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.7 <TTL / IH<0.8。

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.8 <f1 / f<3。

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -1.2 <f2 / f<-0.8。

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.3 <f3 / f<0.5。

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1.2 <f4 / f<-0.5。

[0022] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.6 <f5 / f<2。

[0023] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -25 <f6 / f<-15。

[0024] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -20 <f7 / f<-10。

[0025] Further preferably, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -0.85 <f8 / f<-0.65。

[0026] Compared with the prior art, the optical lens provided by the present invention, through a specific surface shape setting and reasonable optical focal length distribution, effectively shortens the overall length of the optical lens while having a large aperture, and can achieve high-definition imaging even in a dim environment; it can also achieve the large target surface characteristics of the lens, and can be matched with a 1-inch ultra-large bottom COMS chip, which is conducive to improving the lens resolution and image detail restoration; it can better achieve the humanistic imaging effect of a focal length of nearly 35mm, and can capture a more realistic picture. In addition, the optical lens of the present invention has a telephoto characteristic, which can achieve a shooting experience of bringing distant scenes closer, which is conducive to better achieving a small depth of field shooting effect, blurring the background, and highlighting the subject; at the same time, it can also reasonably correct the overall aberration of the optical lens, so that the optical lens has small distortion and high relative illumination, and improves the imaging quality of the optical lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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:

[0028] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0029] Figure 2 4 is a F-Tanθ distortion curve diagram of the optical lens in Example 1 of the present invention.

[0030] Figure 3 Graph showing the vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0031] Figure 4 This is a relative illumination curve diagram of the optical lens in Example 1 of the present invention.

[0032] Figure 5 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0033] Figure 6 4 is a F-Tanθ distortion curve diagram of the optical lens in Example 2 of the present invention.

[0034] Figure 7 Graph showing the vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0035] Figure 8 This is a relative illumination curve diagram of the optical lens in Example 2 of the present invention.

[0036] Fig. 9 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0037] Fig.10 4 is a F-Tanθ distortion curve diagram of the optical lens in Example 3 of the present invention.

[0038] Fig.11 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0039] Fig.12 This is a relative illumination curve diagram of the optical lens in Example 3 of the present invention.

[0040] Fig.13 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0041] Fig.14 4 is a F-Tanθ distortion curve of the optical lens in Example 4 of the present invention.

[0042] Fig.15 Graph showing the vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0043] Fig.16 This is a relative illumination curve diagram of the optical lens in Example 4 of the present invention.

[0044] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] In some embodiments, the first lens may have a positive focal power, with its object side being convex and its image side being concave. The second lens may have a negative focal power, with its object side being convex and its image side being concave. The third lens may have a positive focal power, with its object side being convex and its image side being concave. The fourth lens may have a negative focal power, with its object side being concave near the optical axis and its image side being concave. The fifth lens may have a positive focal power, with its object side being convex and its image side being concave. The sixth lens may have a negative focal power, with its object side being either concave or convex and its image side being either concave or convex. The seventh lens may have a negative focal power, with its object side being concave and its image side being convex. The eighth lens may have a negative focal power, with its object side being concave and its image side being either concave or convex.

[0054] In some embodiments, the optical lens may further include a diaphragm, which may be located between the object side and the first lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the imaging.

[0055] 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 interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting the normal imaging.

[0056] 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: 32 < f×(43.27 / IH) < 35. Meeting the above conditions can make the equivalent focal length of the lens have an imaging with a near 35mm humanities focal length, and the imaging angle of view is close to the human eye view angle, which can better highlight the shooting subject, is beneficial to improving the natural realism of the imaging picture, and brings a better imaging experience to users.

[0057] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 0.92 < TTL / f < 1. Meeting the above conditions, by controlling the ratio of the total optical length and the focal length of the lens within a small range, it is ensured that under the condition of the same focal length, the total length of the lens is smaller, which is beneficial to realizing miniaturization and facilitating being mounted on thin and light electronic devices.

[0058] In some embodiments, the total 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: 0.7 < TTL / IH < 0.8. Meeting the above conditions, it is ensured that under the condition of the same total length of the lens, there is a larger image plane, which can match a larger-sized imaging chip to achieve high-definition imaging, and better achieve the balance between the small total length and the large image plane of the lens.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.8 < f1 / f < 3; the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.7 < R1 / R2 < 1. Meeting the above conditions is beneficial to collecting light at large angles, while reducing the height of the light incident on the first lens, which is conducive to realizing the miniaturization of the lens; at the same time, the degree of deflection of the light emerging from the first lens can be made smaller, which is beneficial to reducing the sensitivity of the lens.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -1.2 < f2 / f < -0.8; the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: 1.2 < R3 / R4 < 2. Meeting the above conditions can effectively diverge the light trend emerging from the first lens, enabling the light to transition smoothly to the rear, reducing the difficulty of correcting aberration; at the same time, it can also enable the light emerging from the first lens to have a larger light receiving surface when entering the rear optical system, achieving a larger light input amount, which is beneficial to increasing the relative illuminance of the captured image.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.3 < f3 / f < 0.5; the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: 0.05 < R5 / R6 < 0.15. Meeting the above conditions is beneficial to the further convergence of light, enabling the diverging light to smoothly enter the rear optical system and better realizing the high-quality imaging of the lens.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1.2 < f4 / f < -0.5; the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: -7 < R7 / R8 < -2. Meeting the above conditions is beneficial to slowing down the degree of deflection of the incident light, avoiding excessive aberration caused by overly strong refractive changes, and at the same time is beneficial to balancing various aberrations generated by the front lens group and improving the overall imaging quality.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.6 < f5 / f < 2; 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: 0.01 < R9 / R10 < 0.3. Meeting the above conditions can control the spherical aberration contribution of the fifth lens within a reasonable range, enabling the lens to have a high axial imaging resolution ability, which is beneficial to realizing the high-definition imaging of the lens.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -25 < f6 / f < -15; the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: 0.1 < R11 / R12 < 1.3. Meeting the above conditions can effectively improve the aberration of the edge field of view and enhance the overall imaging quality of the optical lens.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -20 < f7 / f < -10; the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: 0.1 < R13 / R14 < 1. Meeting the above conditions is beneficial to increasing the divergence degree of light, increasing the area of light entering the imaging surface, realizing large target surface imaging of the lens, and enhancing the imaging quality of the optical lens.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -0.85 < f8 / f < -0.65; the radius of curvature R15 of the object side surface of the eighth lens and the radius of curvature R16 of the image side surface of the eighth lens satisfy: |R15 / R16| < 0.2. Meeting the above conditions can reduce the light energy loss caused by the excessive main ray angle of the large field of view light when reaching the image surface, and is beneficial to enhancing the relative illumination of the edge field of view.

[0067] In some embodiments, the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: BFL / TTL < 0.12; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: BFL / f < 0.1. Meeting the above conditions can make the lens have an appropriate back focus, ensure the compatibility between the lens and the fuselage, and make the structure of the lens more compact.

[0068] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -3 < f1 / f2 < -2. Meeting the above conditions ensures that the light entering the system is diverged to a large extent, which is beneficial to realizing large target surface imaging of the lens.

[0069] In some embodiments, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -0.1 < f5 / f6 < -0.01. Meeting the above conditions is beneficial to the smooth transition of light by reasonably setting the proportion of the focal lengths of the lenses in the lens, and at the same time correcting various aberrations of the optical lens, and enhancing the imaging quality of the optical lens.

[0070] In some embodiments, the focal length f1 of the first lens and the focal length f8 of the eighth lens satisfy: -5 < f1 / f8 < -2. Meeting the above conditions, by reasonably setting the focal length relationship between the first and last lenses in the lens, while ensuring that as much light as possible enters the system, the area of light entering the imaging surface is increased, which is beneficial to achieving large image plane imaging of the lens. At the same time, the light input is increased to achieve large aperture imaging of the lens.

[0071] In some embodiments, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -3 < f12 / f < -1.5. Meeting the above conditions ensures that the light entering the system is diverged to a greater extent, which is beneficial to achieving large target plane imaging of the lens.

[0072] In some embodiments, the combined focal length f23 of the second lens and the third lens and the effective focal length f of the optical lens satisfy: 0.6 < f23 / f < 1. Meeting the above conditions can better correct the axial aberration and improve the resolution.

[0073] In some embodiments, the clear aperture radius DM11 of the object side of the first lens and the clear aperture radius DM81 of the object side of the eighth lens satisfy: 0.6 < DM11 / DM81 < 0.7. Meeting the above conditions enables the lens to have a larger incident aperture, increases the light flux entering the system, and is beneficial to achieving the large aperture performance of the lens and increasing the relative illumination of the edge field of view.

[0074] In some embodiments, the optical lens satisfies the conditional formula: 12mm < TTL < 13mm, 13mm < f < 14mm, 16.5mm < IH < 18mm, Fno < 2, 60° < FOV < 70°; where TTL represents the overall optical length of the optical lens, f represents the effective focal length of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, Fno represents the aperture value of the optical lens, and FOV represents the maximum field of view angle of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention can achieve imaging effects in the near 35mm humanities focal length range. The imaging perspective is close to the human eye perspective. It not only has a large target plane, allows the lens to be paired with an extra-large bottom COMS chip (such as 1 inch), which is beneficial to improving the lens resolution and the detail restoration degree of the image, and achieving higher pixel imaging; it has a long focal length characteristic, can achieve the shooting experience of bringing distant scenes closer, is beneficial to better achieving the shooting effect of small depth of field, blurring the background and highlighting the subject; it has a large aperture performance and can achieve high-definition imaging even in a dim environment.

[0075] In some embodiments, the lens material in the optical lens provided by the present invention may be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt a full plastic lens structure, which not only makes the lens have excellent imaging performance, but also makes the structure of the lens more compact, and can better achieve a balance between miniaturization of the lens and high image quality.

[0076] 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 spherical structures, aspherical structures can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and reducing the size of lenses, and better realizing miniaturization of lenses. 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 may all be aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and reducing the size of lenses, and better realizing miniaturization of lenses.

[0077] In various embodiments of the present invention, when the lens is an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0078] ;

[0079] Among them, 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 surface vertex, K is the quadratic surface coefficient, B, C, D, E, F, G, H, I, and J are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order, eighteenth-order, and twentieth-order surface coefficients respectively.

[0080] 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.

[0081] Example 1

[0082] See also Figure 1, which is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention, wherein the optical lens includes, in sequence from the object side to the imaging surface along the optical axis: 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 L8 and a filter G1.

[0083] The first lens L1 has positive refractive power, its object side surface S1 is convex, and its image side surface S2 is concave;

[0084] The second lens L2 has negative refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0085] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0086] The fourth lens L4 has negative refractive power, its object side surface S7 is concave at the near optical axis, and its image side surface S8 is concave;

[0087] The fifth lens L5 has positive refractive power, its object-side surface S9 is convex, and its image-side surface S10 is concave;

[0088] The sixth lens L6 has negative refractive power, its object-side surface S11 is concave, and its image-side surface S12 is convex;

[0089] The seventh lens L7 has negative refractive power, its object-side surface S13 is concave, and its image-side surface S14 is convex;

[0090] The eighth lens L8 has negative refractive power, its object-side surface S15 is concave, and its image-side surface S16 is convex;

[0091] The object side surface S17 and the image side surface S18 of the filter G1 are both planes;

[0092] The imaging surface S19 is a plane.

[0093] 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.

[0094] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0095] Table 1-1

[0096]

[0097] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0098] Table 1-2

[0099]

[0100] Figure 2 The F-Tanθ distortion curve of the optical lens 100 in this embodiment is shown, which represents the distortion of different field angles on the imaging surface, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the 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.

[0101] Figure 3 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 field angle (unit: °). It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2 μm, indicating that the optical lens 100 can correct the chromatic aberration well.

[0102] Figure 4 The relative illumination curve of the optical lens 100 in this embodiment is shown, which represents the relative illumination values ​​at different field angles on the imaging surface, with the horizontal axis representing the field angle (unit: °) and the vertical axis representing the relative illumination (unit: %). It can be seen from the figure that the relative illumination value of the optical lens is still greater than 30% at the maximum half field angle, indicating that the optical lens 100 has a good relative illumination.

[0103] Example 2

[0104] 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 S11 of the sixth lens L6 is a convex surface at the near optical axis; the image-side surface S12 of the sixth lens L6 is a concave surface at the near optical axis; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0105] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0106] Table 2-1

[0107]

[0108] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0109] Table 2-2

[0110]

[0111] In this embodiment, the F-Tanθ distortion curve, the vertical axis chromatic aberration curve, and the relative illumination curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 shown.

[0112] 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.

[0113] from Figure 7 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.

[0114] from Figure 8 It can be seen that the relative illumination value of the optical lens is still greater than 30% at the maximum half field of view angle, indicating that the optical lens 200 has good relative illumination.

[0115] Example 3

[0116] 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 S11 of the sixth lens L6 is a convex surface at the near optical axis; the image-side surface S12 of the sixth lens L6 is a concave surface at the near optical axis; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0117] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0118] Table 3-1

[0119]

[0120] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0121] Table 3-2

[0122]

[0123] In this embodiment, the F-Tanθ distortion curve, the vertical axis chromatic aberration curve, and the relative illumination curve of the optical lens 300 are respectively as follows: Fig.10 , Fig.11 , Fig.12 shown.

[0124] 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.

[0125] from Fig.11 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 300 can correct chromatic aberration well.

[0126] from Fig.12 It can be seen that the relative illumination value of the optical lens is still greater than 30% at the maximum half field of view, indicating that the optical lens 300 has good relative illumination.

[0127] Example 4

[0128] See also Fig.13 , which is a schematic diagram of the structure of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the image side surface S16 of the eighth lens L8 is a concave surface at the near optical axis; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0129] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0130] Table 4-1

[0131]

[0132] The surface parameters of the aspherical lens of the optical lens in Example 4 are shown in Table 4-2.

[0133] Table 4-2

[0134]

[0135] In this embodiment, the F-Tanθ distortion curve, the vertical axis chromatic aberration curve, and the relative illumination curve of the optical lens 400 are respectively as follows: Fig.14 , Fig.15 , Fig.16 shown.

[0136] from Fig.14 It can be seen that the distortion value is controlled within ±2%, indicating that the optical lens 400 can correct the distortion well.

[0137] from Fig.15 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 400 can correct chromatic aberration well.

[0138] from Fig.16 It can be seen that the relative illumination value of the optical lens is still greater than 30% at the maximum half field of view angle, indicating that the optical lens 400 has good relative illumination.

[0139] Please refer to Table 5, 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.

[0140] Table 5

[0141]

[0142] In summary, the optical lens provided by the present invention has at least the following advantages:

[0143] (1) Through specific surface shape settings and reasonable optical focal length distribution, it is possible to achieve an imaging effect close to the 35mm human focal length. The imaging perspective is close to that of the human eye, which can capture a wide scene while retaining sufficient details and depth. When taking photos, it can better highlight the subject, which is conducive to enhancing the natural realism of the imaging picture and bringing a better imaging experience to users.

[0144] (2) The lens can effectively shorten the overall length of the optical lens while also having a compact large aperture structure, which enables high-definition imaging even in dim environments. It can also realize the large target surface characteristics of the lens and can be paired with a 1-inch ultra-large bottom COMS chip, which is beneficial to improving the lens resolution and image detail restoration.

[0145] (3) The lens has a telephoto feature, which enables the shooting experience of bringing distant scenes closer, which is conducive to better achieving the shooting effect of a small depth of field, blurring the background and highlighting the subject.

[0146] (4) The optical lens of the present invention can reasonably correct the overall aberration of the optical lens. The lens can achieve a large field of view, small distortion, and high relative illumination, so that the optical lens has high pixels and improves the imaging quality of the optical lens.

[0147] 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.

[0148] 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: Along the optical axis from the object side to the imaging surface, it includes: The first lens has positive refractive power, its object side surface is convex, and its image side surface is concave; The second lens has a negative optical power, its object side surface is convex, and its image side surface is concave; The third lens has positive power, its object side surface is convex, and its image side surface is concave; The fourth lens element has a negative optical power, the object side surface of which is concave at the near optical axis, and the image side surface of which is concave; a fifth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is concave; a sixth lens having negative optical power; a seventh lens element having negative optical power, whose object side surface is concave and whose image side surface is convex; an eighth lens having negative optical power, whose object side surface is concave; Wherein, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: <f×(43.27 / IH)<35。 2. The optical lens according to claim 1, characterized in that: The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 0.92 <TTL / f<1。 3. The optical lens according to claim 1, characterized in that: The total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.7 <TTL / IH<0.8。 4. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.8 <f1 / 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 f2 of the second lens satisfy: -1.2 <f2 / f<-0.8。 6. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.3 <f3 / f<0.5。 7. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1.2 <f4 / f<-0.5。 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: 0.6 <f5 / f<2。 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: -25 <f6 / f<-15。 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: -20 <f7 / f<-10。 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: -0.85 <f8 / f<-0.65。

Images