Optical lens

Abstract

The present invention provides an optical lens having seven lenses, which include, in order from the object side to the imaging surface along the optical axis: a first lens having positive optical power, whose object side surface is convex and whose image side surface is concave at the near optical axis; a second lens having positive optical power, whose object side surface is convex and whose image side surface is convex; a third lens having negative optical power, whose object side surface is concave at the near optical axis and whose image side surface is concave; a fourth lens having positive optical power, whose object side surface is convex at the near optical axis; a fifth lens having positive optical power, whose object side surface is concave and whose image side surface is convex; a sixth lens having negative 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; and a seventh lens having negative optical power, whose object side surface is concave. The optical lens provided by the present invention can reasonably correct the overall aberration of the optical lens, so that the optical lens has one or more advantages such as a large aperture, a large target area, miniaturization, and high imaging quality.

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] In recent years, with the rapid iteration of smartphone camera functions, users have increasingly higher requirements for the imaging performance of mobile devices. As the core component of mobile phone camera modules, optical lenses need to achieve comprehensive performance such as large aperture, high resolution, and large target surface adaptation within a limited space, while meeting the design requirements of miniaturization of the total length of the lens to adapt to the development trend of ultra-thin bodies. With the development of image sensor technology and the pursuit of higher imaging quality photography effects, optical lenses usually adopt a multi-lens structure solution, among which seven-lens structure lenses are gradually becoming the mainstream design solution. However, how to coordinately optimize the F / 1.68 ultra-large aperture, adapt to large target surface sensors larger than 1 / 1.3 inches, and achieve higher imaging resolution under a compact optical architecture remains a technical difficulty that urgently needs to be overcome in this field. Summary of the Invention

[0003] In view of the above problems, the object of the present invention is to provide an optical lens having one or more advantages such as large aperture, large target area, miniaturization, and high imaging quality.

[0004] The technical solution adopted in the present invention is:

[0005] An optical lens, comprising seven lenses, including the following elements in order from the object side to the imaging surface along the optical axis:

[0006] The first lens has positive refractive power, its object-side surface is convex, and its image-side surface is concave near the optical axis;

[0007] a second lens having positive refractive power, its object-side surface being convex and its image-side surface being convex;

[0008] The third lens element has a negative optical power, the object side surface of which is concave near the optical axis and the image side surface of which is concave;

[0009] a fourth lens element having positive optical power and a convex object-side surface near the optical axis;

[0010] a fifth lens element having positive refractive power, whose object-side surface is concave and whose image-side surface is convex;

[0011] a sixth lens element having negative optical power, wherein the object-side surface thereof is convex near the optical axis and the image-side surface thereof is concave near the optical axis;

[0012] a seventh lens element having negative optical power and a concave object-side surface;

[0013] Among them, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -1.6 < f3 / f < -1.4; 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: -2 < R3 / R4 < -0.4; the curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: -5.4 < R5 / R6 < -0.7.

[0014] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1.1 < f1 / f < 1.3; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.6 < f2 / f < 1.8.

[0015] Further preferably, the central thickness CT2 of the second lens on the optical axis and the edge thickness ET2 of the second lens satisfy: 1.8 < ET2 / CT2 < 2.5; the central thickness CT3 of the third lens on the optical axis and the edge thickness ET3 of the third lens satisfy: 0.5 < ET3 / CT3 < 0.7.

[0016] Further preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 5 < f4 / f < 13.

[0017] Further preferably, 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: -0.5 < (R3 + R4) / (R3 - R4) < 0.4; the curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: -0.2 < (R5 + R6) / (R5 - R6) < 0.7.

[0018] Further preferably, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -1.2 < f2 / f3 < -1.1.

[0019] Further preferably, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.6 < TTL / IH < 0.65.

[0020] Further preferably, the overall optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens on the optical axis respectively satisfy: 0.5 < ∑CT / TTL < 0.57.

[0021] Further preferably, the true image height IH corresponding to the maximum field angle of the optical lens and the F - number Fno of the optical lens satisfy: 7.3mm < IH / Fno < 7.8mm.

[0022] Further preferably, the center thickness CT6 of the sixth lens on the optical axis and the sag SAG61 corresponding to the maximum light semi-aperture of the object side of the sixth lens meet the following requirements: 0.9 <CT6 / |SAG61|<1.2。

[0023] Compared with the existing technology, the optical lens provided by the present invention has a small size through a specific surface shape setting and reasonable optical focal length distribution; it can also achieve a large image height of the lens and can be used with a large target surface chip, which is beneficial to improving the lens resolution and image detail restoration; the lens has a large aperture, which can achieve high-definition imaging even in dim environments; 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0025] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0026] Figure 2 1 is an axial aberration curve diagram of the optical lens in Example 1 of the present invention.

[0027] Figure 3 Graph showing the magnification chromatic aberration of the optical lens in Example 1 of the present invention.

[0028] Figure 4 2 is a distortion curve diagram of the optical lens in Example 1 of the present invention.

[0029] Figure 5 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0030] Figure 6 2 is an axial aberration curve diagram of the optical lens in Example 2 of the present invention.

[0031] Figure 7 2 is a graph showing the magnification chromatic aberration curve of the optical lens in Example 2 of the present invention.

[0032] Figure 8 This is a distortion curve diagram of the optical lens in Example 2 of the present invention.

[0033] Figure 9 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0034] Figure 10 4 is an axial aberration curve diagram of the optical lens in Example 3 of the present invention.

[0035] Figure 11Graph showing the magnification chromatic aberration of the optical lens in Example 3 of the present invention.

[0036] Figure 12 2 is a distortion curve diagram of the optical lens in Example 3 of the present invention.

[0037] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0038] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of 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.

[0039] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0040] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0041] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, 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 "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 preclude 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 list of 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.

[0043] Unless otherwise defined, all terms (including technical and scientific terms) used herein shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0044] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments may be combined with each other. The following will detail this application in conjunction with the accompanying drawings and embodiments.

[0045] The optical lens provided by an embodiment of the present invention has a total of seven lenses, which are, in order from the object side to the imaging surface along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

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

[0047] In some embodiments, the optical lens may further include an aperture stop, and the aperture stop may be located between the object side and the first lens. It can be understood that the aperture stop is used to limit the amount of incident light to change the brightness of the image.

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

[0049] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -1.6 < f3 / f < -1.4. Meeting the above conditions, the negative lens of the third lens can adjust the principal ray angle and reduce the barrel distortion of the wide-angle lens.

[0050] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -2 < R3 / R4 < -0.4. Meeting the above conditions, the second lens has a strong positive optical power, which can offset the spherical aberration generated by the first lens.

[0051] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: -5.4 < R5 / R6 < -0.7. Meeting the above conditions, the third lens can balance the field curvature of the system, avoid deterioration of the image quality at the edges, and meet the requirements of a large field angle (such as ultra-wide angle or main camera) of a mobile phone lens.

[0052] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1.1 < f1 / f < 1.3. Meeting the above conditions, the first lens moderately converges, which can balance the aberration contributions of the front group and the rear group and avoid deterioration of the image quality in the marginal field of view.

[0053] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.6 < f2 / f < 1.8. Meeting the above conditions, the light path direction can be controlled, providing a more reasonable light incident angle for the subsequent lenses, and reducing astigmatism and field curvature.

[0054] In some embodiments, the central thickness CT2 of the second lens on the optical axis and the edge thickness ET2 of the second lens satisfy: 1.8 < ET2 / CT2 < 2.5; the central thickness CT3 of the third lens on the optical axis and the edge thickness ET3 of the third lens satisfy: 0.5 < ET3 / CT3 < 0.7. For the second lens and the third lens meeting the above conditions, the curvature combination of the biconvex and biconcave lenses can reduce the field curvature and ensure clear images at both the center and the edges.

[0055] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 5 < f4 / f < 13. Meeting the above conditions, by reasonably setting the focal length of the fourth lens, it is beneficial for the smooth transition of light, facilitating the correction of astigmatism and field curvature, improving the imaging quality of the optical lens, and ensuring the stability of the optical system.

[0056] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -0.5 < (R3 + R4) / (R3 - R4) < 0.4; the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: -0.2 < (R5 + R6) / (R5 - R6) < 0.7. Meeting the above conditions, the radii of curvature of the object side surface and the image side surface of the second and third lenses near the optical axis are reasonably controlled, which is beneficial for controlling the shapes of the second and third lenses, optimizing the aberration balance of the lens group, and improving the imaging quality.

[0057] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -1.2 < f2 / f3 < -1.1. Meeting the above conditions can enable the second lens and the third lens to form chromatic aberration compensation, and help compress the system length and balance the field curvature.

[0058] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.6 < TTL / IH < 0.65. Meeting the above conditions can better achieve the miniaturization of the lens, and at the same time ensure that the lens has a larger image plane under the condition of the same total length of the lens, and can match a larger-sized imaging chip to achieve high-definition imaging.

[0059] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens on the optical axis respectively satisfy: 0.5 < ∑CT / TTL < 0.57. Meeting the above conditions can effectively compress the total length of the optical lens, and at the same time is beneficial to the structural design and production process of the optical lens.

[0060] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the aperture value Fno of the optical lens satisfy: 7.3mm < IH / Fno < 7.8mm. Meeting the above conditions can maintain a large image plane of the optical lens while ensuring that the optical lens has a large aperture, achieving the balance of a large image plane and a large aperture.

[0061] In some embodiments, the central thickness CT6 of the sixth lens on the optical axis and the sagittal height SAG61 corresponding to the maximum clear aperture radius of the object side surface of the sixth lens satisfy: 0.9 < CT6 / |SAG61| < 1.2. Meeting the above conditions can control the surface shape of the object side surface of the sixth lens, which is beneficial to the manufacturing and forming of the sixth lens, and reduces the defective rate. In addition, it can also avoid the surface shape being too curved and complex, making the system field curvature tend to be balanced.

[0062] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < f5 / f < 1.4. Meeting the above conditions, the fifth lens has a positive optical power, which can further focus the light, optimize the imaging quality, and correct the remaining aberrations (such as distortion, chromatic aberration, etc.), thereby ensuring the imaging clarity and color restoration.

[0063] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -17 < f6 / f < -3. Meeting the above conditions, by setting the sixth lens to have a large negative optical power, the incident light can be diverged to a large extent, making the peripheral light and the central light turn upwards, reaching a higher imaging position, better realizing the large target surface imaging of the lens, and improving the imaging quality.

[0064] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1 < f7 / f < -0.5. Meeting the above conditions, the seventh lens can extend the light convergence point and increase the BFL; and can avoid excessive angles of marginal rays and match the sensor CRA.

[0065] 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: -4.7 < (R7 + R8) / (R7 - R8) < -0.85. Meeting the above conditions can reduce the light deflection angle, make the light trend smoother; at the same time, it can correct coma and field curvature, improve the flatness of imaging, and enhance the imaging quality of the optical lens.

[0066] In some embodiments, the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 3.5 < |R14 / f| < 17. Meeting the above conditions is beneficial to alleviating the deflection degree of light passing through the lens and can well reduce aberration.

[0067] In some embodiments, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: -1.6 < f1 / f7 < -1.3. Meeting the above conditions, by reasonably setting the focal length ratio 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.

[0068] In some embodiments, the clear aperture radius DM11 of the object side surface of the first lens and the clear aperture radius DM72 of the image side surface of the seventh lens satisfy: 0.35 < DM11 / DM72 < 0.4. Meeting the above conditions, by reasonably setting the aperture ratio 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.

[0069] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3 < IH / EPD < 3.5. Meeting the above conditions enables the optical lens to meet the large image surface while also ensuring sufficient image surface brightness in the marginal field of view, preventing the occurrence of vignetting, and thus enhancing the imaging quality.

[0070] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.98 < (2×f×tan(FOV / 2)) / IH < 0.99. Meeting the above conditions can make the lens have a smaller distortion value and provide a high-definition imaging effect.

[0071] In some embodiments, the optical lens satisfies the conditional formula: 7.8mm < TTL < 8mm; 87° < FOV < 88°; 12mm < IH < 13mm; 1.6 < Fno < 1.7; where TTL represents the total optical length of the optical lens, FOV represents the maximum field angle of the optical lens, IH represents the true image height corresponding to the maximum field angle of the optical lens, and Fno represents the aperture value 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 short total length. While achieving the characteristics of a large aperture, a large target surface, and high quality, it compresses the total optical length, which is beneficial to the miniaturization and portability of the device; it has a large field angle, providing a wider shooting field of view for the mobile phone lens and capturing more image information; it has a large image height, can adapt to a large target surface sensor with a size larger than 1 / 1.3 inches, and provides higher-quality imaging quality; it has a large aperture, further improving the light input of the lens among seven lenses, and providing greater possibilities for high-quality imaging and optical anti-shake of the mobile phone lens.

[0072] In some embodiments, the lens material of 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. On the other hand, 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 fully 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 between the miniaturization of the lens and high image quality.

[0073] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh 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, and the seventh 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.

[0074] In each embodiment of the present invention, when the lens adopts an aspherical lens, the surface shape of the aspherical lens satisfies the following equation:

[0075] ;

[0076] where z is the sagitta of the distance from the vertex of the aspherical surface at the position with a height of h along the optical axis direction, c is the paraxial curvature of the surface, k is the conic coefficient, and A 2i is the aspherical surface type coefficient of the 2i-th order.

[0077] The present invention is further illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0078] Example 1

[0079] See also Figure 1 , shown is a schematic structural diagram of the optical lens 100 provided in Example 1 of the present invention, which 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, and a filter G1.

[0080] The first lens L1 has positive refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave near the optical axis;

[0081] The second lens L2 has positive refractive power, its object-side surface S3 is convex, and its image-side surface S4 is convex;

[0082] The third lens L3 has negative refractive power, its object-side surface S5 is concave near the optical axis, and its image-side surface S6 is concave;

[0083] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex near the optical axis, and its image-side surface S8 is convex;

[0084] The fifth lens L5 has positive refractive power, its object-side surface S9 is concave, and its image-side surface S10 is convex;

[0085] The sixth lens L6 has negative refractive power, its object-side surface S11 is convex near the optical axis, and its image-side surface S12 is concave near the optical axis;

[0086] The seventh lens L7 has negative refractive power, its object-side surface S13 is concave, and its image-side surface S14 is convex;

[0087] The object-side surface S15 and the image-side surface S16 of the filter G1 are both flat surfaces;

[0088] The imaging surface S17 is a plane.

[0089] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all plastic aspherical lenses.

[0090] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0091] Table 1-1

[0092]

[0093] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0094] Table 1-2

[0095]

[0096] In this embodiment, the axial aberration curve, the magnification chromatic aberration curve, and the distortion curve of the optical lens 100 are respectively as follows: Figure 2 、 Figure 3 、 Figure 4 shown.

[0097] Figure 2 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane, with the horizontal axis representing the axial aberration value (unit: mm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ±0.04mm, indicating that the optical lens 100 is able to correct the axial aberration well.

[0098] Figure 3 The following graph shows the magnification chromatic aberration curve for Example 1, which represents the chromatic aberration of each wavelength relative to the central wavelength (550 nm) at different image heights on the imaging plane. The horizontal axis represents the chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the chromatic aberration between the longest and shortest wavelengths is controlled within ±4 μm, indicating that the optical lens 100 can effectively correct chromatic aberration.

[0099] Figure 4 A distortion curve for Example 1 is shown, showing the distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the image height (unit: mm). As can be seen from the graph, the distortion of the optical lens is controlled within 0-3%, indicating that the optical lens 100 is capable of effectively correcting distortion.

[0100] Example 2

[0101] See also Figure 5, shown is a schematic structural diagram of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S8 of the fourth lens L4 is concave at the near optical axis; the image-side surface S14 of the seventh lens L7 is concave at the near optical axis; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0102] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0103] Table 2-1

[0104]

[0105] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0106] Table 2-2

[0107]

[0108] In this embodiment, the axial aberration curve, the magnification chromatic aberration curve, and the distortion curve of the optical lens 200 are respectively as follows: Figure 6 、 Figure 7 、 Figure 8 shown.

[0109] from Figure 6 It can be seen from the figure that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 200 can correct the axial aberration well.

[0110] from Figure 7 It can be seen from the figure that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±2 μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0111] from Figure 8 It can be seen from the figure that the distortion of the optical lens is controlled within -1%~3%, indicating that the optical lens 200 can correct the distortion well.

[0112] Example 3

[0113] See also Figure 9 , shown is a schematic structural diagram of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S8 of the fourth lens L4 is concave at the near optical axis; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0114] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0115] Table 3-1

[0116]

[0117] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0118] Table 3-2

[0119]

[0120] In this embodiment, the axial aberration curve, the magnification chromatic aberration curve, and the distortion curve of the optical lens 300 are respectively as follows: Figure 10 、 Figure 11 、 Figure 12 shown.

[0121] from Figure 10 It can be seen from the figure that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 300 can correct the axial aberration well.

[0122] from Figure 11 It can be seen from the figure that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±2 μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0123] from Figure 12 It can be seen that the distortion of the optical lens is controlled within 0~3%, indicating that the optical lens 300 can correct the distortion well.

[0124] Please refer to Table 4, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, real image height IH corresponding to the maximum field of view angle, maximum field of view angle FOV, chief ray incidence angle CRA at the maximum image height, and the numerical value corresponding to each conditional expression in each embodiment.

[0125] Table 4

[0126]

[0127] In summary of the above embodiments, the optical lens provided by the present invention has at least the following advantages:

[0128] The optical lens provided by the present invention has a small size through a specific surface shape setting and reasonable optical focal length distribution; it can also achieve a large image height of the lens and can be used with a large target surface chip, which is beneficial to improving the lens resolution and image detail restoration; the lens has a large aperture, which can achieve high-definition imaging even in dim environments; it can also reasonably correct the overall aberration of the optical lens, so that the optical lens has a high pixel and improves the imaging quality of the optical lens.

[0129] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations 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 any one or more embodiments or examples.

[0130] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, comprising seven lenses, characterized in that: From the object side to the imaging surface along the optical axis, it sequentially includes: A first lens with positive optical power, whose object side is convex and whose image side is concave near the optical axis; A second lens with positive optical power, whose object side is convex and whose image side is convex; A third lens with negative optical power, whose object side is concave near the optical axis and whose image side is concave; A fourth lens with positive optical power, whose object side is convex near the optical axis; A fifth lens with positive optical power, whose object side is concave and whose image side is convex; A sixth lens with negative 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; Wherein, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -1.6 < f3 / f < -1.4; 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: -2 < R3 / R4 < -0.4; the curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: -5.6 < R5 / R6 < -0.

7.

2. The optical lens according to claim 1, wherein: The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1.1 < f1 / f < 1.3; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.6 < f2 / f < 1.

8.

3. The optical lens according to claim 1, wherein: The central thickness CT2 of the second lens on the optical axis and the edge thickness ET2 of the second lens satisfy: 1.8 < ET2 / CT2 < 2.5; the central thickness CT3 of the third lens on the optical axis and the edge thickness ET3 of the third lens satisfy: 0.5 < ET3 / CT3 < 0.

7.

4. The optical lens according to claim 1, wherein: The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 5 < f4 / f < 13.

5. The optical lens according to claim 1, wherein: 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: -0.5 < (R3 + R4) / (R3 - R4) < 0.4; the curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: -0.2 < (R5 + R6) / (R5 - R6) < 0.

7.

6. The optical lens according to claim 1, wherein: The focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -1.2 < f2 / f3 < -1.

1.

7. The optical lens according to claim 1, wherein: The overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.6 < TTL / IH < 0.

65.

8. The optical lens according to claim 1, wherein: The overall optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens on the optical axis respectively satisfy: 0.5 < ∑CT / TTL < 0.

57.

9. The optical lens according to claim 1, wherein: The true image height IH corresponding to the maximum field angle of the optical lens and the F-number Fno of the optical lens satisfy: 7.3mm < IH / Fno < 7.8mm.

10. The optical lens according to claim 1, wherein: The center thickness CT6 of the sixth lens on the optical axis and the sag height SAG61 corresponding to the maximum light semi-aperture of the object side of the sixth lens meet the following requirements: 0.9 <CT6 / |SAG61|<1.2。

Images