Optical lens

Abstract

The invention provides an optical lens, which sequentially comprises a first lens with negative focal power from an object side to an imaging surface along an optical axis, a second lens with negative focal power, a third lens with positive focal power and a fourth lens with negative focal power from the object side to the imaging surface, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a convex surface; and the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface. According to the optical lens provided by the invention, through specific surface shape arrangement and reasonable focal power distribution, the lens has the advantage of excellent imaging quality.

Description

Technical Field

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

[0002] Law enforcement recorders are mainly used for digitally recording the on-site situation during law enforcement, such as video recording, photographing, voice recording, etc., so as to provide effective on-site image data afterwards. During on-site law enforcement, law enforcement officers need to record a large range and clear images. However, the lenses of law enforcement recorders on the market either have too small an aperture, resulting in a dark recorded image, or too small a field of view, unable to record too many pictures.

[0003] Therefore, how to make the lens of a law enforcement recorder meet high imaging quality is an urgent problem to be solved at present. Summary of the Invention

[0004] In view of the above problems, the object of the present invention is to provide an optical lens, which has the advantage of excellent imaging quality.

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

[0006] An optical lens is composed of seven lenses, and sequentially includes from the object side to the imaging surface along the optical axis:

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

[0008] A second lens with positive optical power, whose object side is convex and whose image side is concave;

[0009] A third lens with negative optical power, whose object side is convex and whose image side is concave;

[0010] A fourth lens with positive optical power, whose object side is convex and whose image side is convex;

[0011] A fifth lens with positive optical power, whose object side is concave and whose image side is convex;

[0012] A sixth lens with negative optical power, whose object side is concave and whose image side is convex;

[0013] A seventh lens with positive optical power, whose object side is convex and whose image side is concave;

[0014] Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.8 < TTL / f < 5.5; 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: 1.7 < TTL / IH < 2.

[0015] Further preferably, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.6 < IH / f < 3.

[0016] Further preferably, the effective focal length f of the optical lens and the combined focal length fa of the first lens, the second lens, and the third lens satisfy: -1.5 < fa / f < -0.6; the effective focal length f of the optical lens and the combined focal length fb of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: 0.8 < fb / f < 1.5.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.5 < f1 / f < -1.1; 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: 5 < R1 / R2 < 9.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 10 < f2 / f < 50; 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: 0.7 < R3 / R4 < 1.2.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -12 < f3 / f < -3.5; 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: 2 < R5 / R6 < 8.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.85 < f4 / f < 1.3; 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: -2 < R7 / R8 < -1.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.3 < f5 / f < 2.2; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -4 < f6 / f < -1.5.

[0022] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 4 < f7 / f < 15; the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 0.4 < R13 / R14 < 1.

[0023] Further preferably, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.15 < f1 / f2 < -0.02.

[0024] Further preferably, the central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 0.2 < CT2 / CT3 < 0.4; the central thickness of the third lens and the central thickness CT4 of the fourth lens satisfy: 1.4 < CT3 / CT4 < 2.6.

[0025] Compared with the prior art, the optical lens provided by the present invention has a large aperture through specific surface shape settings and reasonable optical power distribution, enabling high-definition imaging even in a dim environment. At the same time, it has an ultra-wide angle, so that more scene information can be obtained to meet the needs of large-range shooting. In addition, it can reasonably correct the overall aberration of the optical lens, achieve high-definition imaging, and improve the imaging quality of the optical lens. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0027] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 2 is an F-Theta distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

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

[0030] Figure 4 is an axial aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 5 is a lateral chromatic aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0032] Figure 6 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 7 is an F-Theta distortion curve diagram of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 8 is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0035] Fig. 9 is an axial aberration curve diagram of the optical lens in Embodiment 2 of the present invention.

[0036] Fig.10 Graph showing the vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0037] Fig.11 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0038] Fig.12 Graph showing the F-Theta distortion of the optical lens in Embodiment 3 of the present invention.

[0039] Fig.13 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0040] Fig.14 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0041] Fig.15 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0042] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] The optical lens provided by the embodiment of the present invention is composed of seven lenses, which include: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens in sequence from the object side to the imaging surface along the optical axis.

[0051] In some embodiments, the first lens may have a negative optical power, with a convex object side surface and a concave image side surface. The second lens may have a positive optical power, with a convex object side surface and a concave image side surface. The third lens may have a negative optical power, with a convex object side surface and a concave image side surface. The fourth lens may have a positive optical power, with a convex object side surface and a convex image side surface. The fifth lens may have a positive optical power, with a concave object side surface and a convex image side surface. The sixth lens may have a negative optical power, with a concave object side surface and a convex image side surface. The seventh lens may have a positive optical power, with a convex object side surface and a concave image side surface.

[0052] In some embodiments, the optical lens may further include a diaphragm, which may be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image. When the diaphragm is located between the third lens and the fourth lens, it is convenient for correcting the diaphragm aberration.

[0053] In some embodiments, the optical lens may further include a filter, which may be disposed between the seventh lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0054] In some embodiments, the fifth lens and the sixth lens may be glued together to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0055] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.8 < TTL / f < 5.5. Meeting the above conditions can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens.

[0056] 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: 1.7 < TTL / IH < 2. Meeting the above conditions ensures that under 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.

[0057] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.6 < IH / f < 3. Meeting the above conditions can not only achieve the wide-angle characteristic to meet the large-range shooting requirements, but also achieve the large-image-plane characteristic to improve the imaging quality of the optical lens.

[0058] In some embodiments, the effective focal length f of the optical lens and the combined focal length fa of the first lens, the second lens, and the third lens satisfy: -1.5 < fa / f < -0.6. Meeting the above conditions, by reasonably setting the negative refractive power of the lens group in front of the diaphragm, it is beneficial to converge the light rays in a large angle range to achieve the ultra-wide-angle characteristic, and at the same time improve the resolution of the edge field of view, and achieve a balance between the short total optical length and the good imaging quality.

[0059] In some embodiments, the effective focal length f of the optical lens and the combined focal length fb of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: 0.8 < fb / f < 1.5. Meeting the above conditions and reasonably setting the positive refractive power of the rear diaphragm lens group is beneficial to balancing the distortion and astigmatism generated by the front lenses of the optical lens and improving the imaging quality of the optical lens.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.5 < f1 / f < -1.1. Meeting the above conditions and setting the first lens to have a negative refractive power and a meniscus shape is beneficial for the first lens to receive a larger angle of light and collect as much light as possible into the rear optical system, achieving a large field of view while increasing the light flux.

[0061] In some embodiments, 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: 5 < R1 / R2 < 9. Meeting the above conditions and setting the first lens to have a convex-concave meniscus surface type helps to converge the incident light, reduce the aperture of the front lens, facilitate the miniaturization of the head, and at the same time, the first lens can be made of glass material, having an anti-scratch effect to prevent the lens from being worn during use and affecting the imaging quality.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 10 < f2 / f < 50; 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: 0.7 < R3 / R4 < 1.2. Meeting the above conditions can effectively converge a wide range of light entering the system, which is beneficial to avoiding excessive light deflection caused by the overly concentrated optical power of the first lens and reducing the difficulty of correcting aberrations.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -12 < f3 / f < -3.5; 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: 2 < R5 / R6 < 8. Meeting the above conditions is beneficial to slowing down the deflection degree of the incident light, avoiding excessive aberration generated due to overly strong refractive changes, and at the same time, it is beneficial to balancing various aberrations generated by the front lens group and improving the overall imaging quality.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.85 < f4 / f < 1.3. Meeting the above conditions can 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, and improve the overall imaging quality.

[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: -2 < R7 / R8 < -1. Meeting the above conditions, by setting the double convex surface type of the fourth lens, it is beneficial to gently converge light, can shorten the turning distance of light, and further reduce the total length of the optical lens.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.3 < f5 / f < 2.2. Meeting the above conditions is beneficial to improving the light converging ability of the optical lens, and at the same time can balance the aberration of the optical lens and improve the imaging quality of the optical lens.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -4 < f6 / f < -1.5. Meeting the above conditions, by setting the sixth lens to have an appropriate negative optical power, it is beneficial to diverge the light converged by the fourth lens and the fifth lens, and increase the image height of the optical lens.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 4 < f7 / f < 15; 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: 0.4 < R13 / R14 < 1. Meeting the above conditions is beneficial to increasing the area of light entering the imaging surface, realizing large target surface imaging of the lens, and improving the imaging quality of the optical lens.

[0069] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.15 < f1 / f2 < -0.02. Meeting the above conditions, on the premise of ensuring that the optical lens has an ultra-wide angle, it avoids excessive light deflection caused by too concentrated optical power of the first lens, and reduces the difficulty of chromatic aberration correction of the optical lens.

[0070] In some embodiments, the central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 0.2 < CT2 / CT3 < 0.4; the central thickness of the third lens and the central thickness CT4 of the fourth lens satisfy: 1.4 < CT3 / CT4 < 2.6. Meeting the above conditions, while meeting the requirements of assembly stability, it can reduce the assembly deformation and assembly difficulty of the lens, and at the same time make the structure of the lens more compact, which is conducive to realizing the miniaturization of the lens.

[0071] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 60° < (f × FOV) / IH < 65°. Meeting the above conditions, by reasonably restricting the relationship between the focal length, field of view angle and image height of the optical lens, it can ensure that the optical lens has the characteristics of a large field of view and a large image plane.

[0072] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.9 < BFL / f < 1.1. Meeting the above conditions can make the lens have an appropriate back focus, ensure the compatibility between the lens and the camera body, and at the same time make the structure of the lens more compact.

[0073] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -9 < f3 / f4 < -3. Meeting the above conditions is conducive to enabling the diverging light to smoothly enter the rear optical system, reducing the correction difficulty of field curvature and distortion, and improving the overall resolution.

[0074] In some embodiments, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -0.8 < f5 / f6 < -0.5. Meeting the above conditions, by reasonably setting the focal length relationship between the fifth and sixth lenses, the chromatic aberration of the system can be effectively corrected, and the overall imaging quality can be improved.

[0075] In some embodiments, the combined focal length fa of the first lens, the second lens, and the third lens and the combined focal length fb of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: -1 < fa / fb < -0.6. Meeting the above conditions, by reasonably setting the relationship between the lens groups before and after the aperture, it is beneficial to balance various aberrations of the system and improve the overall imaging quality.

[0076] In some embodiments, the effective focal length f of the optical lens and the combined focal length f56 of the fifth lens and the sixth lens satisfy: 5 < f56 / f < 2.5. Meeting the above conditions, the fifth and sixth lenses form a cemented lens with positive optical power. By reasonably setting the focal length and thickness of the fifth and sixth cemented lenses, the incident light can be further converged, the light energy loss can be reduced, and at the same time, the diverging light can be smoothly converged and enter the rear, further making the light trend transition smoothly and improving the relative illumination of the edge field of view.

[0077] In some embodiments, the optical lens satisfies the conditional formula: 17 mm < TTL < 18 mm, 3 mm < f < 5 mm, 9 mm < IH < 10 mm, Fno < 1.9, 165° < FOV < 175°; 13° < CRA < 14°; where TTL represents the total 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, FOV represents the maximum field of view angle of the optical lens, and CRA represents the principal ray incident angle 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 a large field of view angle, can record a large range of images during shooting; has a large target surface, can match the lens with an ultra-large target surface for imaging, is beneficial to improving the lens resolution and the detail restoration degree of the image, and realizes imaging with higher pixels; has a large aperture performance, records brighter images, and can achieve high-definition imaging even in a dim environment; has a small CRA, can better match a small CRA chip, and ensure good resolution quality.

[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. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected due to the low dispersion characteristic of the glass itself. The first lens and the fourth lens in the optical lens provided by the present invention are made of glass lenses, and the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens are all made of plastic lenses.

[0079] 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 be spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens of the present invention is a spherical lens, and the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can all be aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens.

[0080] In each embodiment of the present invention, when the lens is an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0081]

[0082] 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, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients 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 100 includes, in sequence from the object side to the imaging surface S16 along the optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and a filter G1.

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

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

[0088] The third lens L3 has negative refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0089] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is convex;

[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 negative refractive power, its object-side surface S10 is concave, and its image-side surface S11 is convex;

[0092] The fifth lens L5 and the sixth lens L6 form a cemented lens group with positive refractive power, that is, the cemented surface between the image side surface of the fifth lens L5 and the object side surface of the sixth lens L6 is S10;

[0093] The seventh lens L7 has positive refractive power, its object-side surface S12 is convex, and its image-side surface S13 is concave;

[0094] The object side surface S14 and the image side surface S15 of the filter G1 are both planes;

[0095] The imaging surface S16 is a plane.

[0096] The first lens L1 is a glass spherical lens, the fourth lens L4 is a glass aspherical lens, and the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, and the seventh lens L7 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-Theta distortion curve of the optical lens 100 in this embodiment is shown, which represents the distortion of different field angles on the imaging surface, with the horizontal axis representing the distortion value (unit: %) and the vertical axis representing the field angle (unit: °). It can be seen from the figure that the distortion value is controlled within ±8%, 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 represents the field curvature of light in the meridional image plane and the sagittal image plane, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the 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 ±0.5mm, indicating that the optical lens 100 can correct the field curvature well.

[0105] Figure 4 The axial aberration curve of the optical lens 100 in this embodiment is shown, which represents the aberration of each wavelength on the optical axis at the imaging surface, the horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial aberration is controlled within ±0.03mm, indicating that the optical lens 100 can correct the axial aberration well.

[0106] Figure 5The 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 (0.55 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 ±10 μm, indicating that the optical lens 100 can correct the chromatic aberration well.

[0107] Example 2

[0108] See also Figure 6 , 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 difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0109] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0110] Table 2-1

[0111]

[0112]

[0113] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0114] Table 2-2

[0115]

[0116] In this embodiment, the F-Theta distortion curve, field curvature curve, axial aberration curve, and vertical axis chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Fig. 9 , Fig.10 shown.

[0117] from Figure 7 It can be seen that the distortion value is controlled within ±8%, indicating that the optical lens 200 can correct the distortion well.

[0118] from Figure 8 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.25 mm, indicating that the optical lens 200 can correct the field curvature well.

[0119] from Fig. 9 It can be seen that the offset of the axial aberration is controlled within ±0.03 mm, indicating that the optical lens 200 can correct the axial aberration well.

[0120] from Fig.10 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±10 μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0121] Example 3

[0122] See also Fig.11 , 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 difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0123] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0124] Table 3-1

[0125]

[0126] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0127] Table 3-2

[0128]

[0129] In this embodiment, the F-Theta distortion curve, field curvature curve, axial aberration curve, and vertical axis chromatic aberration curve of the optical lens 300 are respectively as follows: Fig.12 , Fig.13 , Fig.14 , Fig.15 shown.

[0130] from Fig.12 It can be seen that the distortion value is controlled within ±9%, indicating that the optical lens 300 can correct the distortion well.

[0131] from Fig.13 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.25 mm, indicating that the optical lens 300 can correct the field curvature well.

[0132] from Fig.14 It can be seen 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.

[0133] from Fig.15 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±10 μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0134] 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.

[0135] Table 4

[0136]

[0137]

[0138] In summary, the optical lens provided by the present invention has at least the following advantages:

[0139] (1) Through specific surface shape settings and reasonable optical focal length distribution, the lens has a large aperture, which can achieve high-definition imaging even in dim environments. At the same time, it has an ultra-wide angle, so that more scene information can be obtained, meeting the needs of large-scale shooting.

[0140] (2) The optical lens of the present invention can reasonably correct the overall aberration of the optical lens, achieve high-definition imaging, and improve the imaging quality of the optical lens.

[0141] (3) The glass-plastic hybrid structure improves the stability of the lens under high and low temperature conditions while improving the imaging quality. At the same time, the lens has a smaller CRA, which can match the chip well and ensure good resolution quality.

[0142] 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.

[0143] 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 seven lenses, characterized in that: It successively includes from the object side to the imaging surface along the optical axis: A first lens with negative optical power, whose object side is convex and whose image side is concave; A second lens with positive optical power, whose object side is convex and whose image side is concave; A third lens with negative optical power, whose object side is convex and whose image side is concave; A fourth lens with positive optical power, whose object side is convex and whose image side is convex; 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 concave and whose image side is convex; A seventh lens with positive optical power, whose object side is convex and whose image side is concave; Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.8 < TTL / f < 5.5; 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: 1.7 < TTL / IH < 2.

2. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.6 < IH / f < 3.

3. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the combined focal length fa of the first lens, the second lens, and the third lens satisfy: -1.5 < fa / f < -0.6; the effective focal length f of the optical lens and the combined focal length fb of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: 0.8 < fb / f < 1.

5.

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: -1.5 < f1 / f < -1.1; 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: 5 < R1 / R2 < 9.

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: 10 < f2 / f < 50; 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: 0.7 < R3 / R4 < 1.

2.

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: -12 < f3 / f < -3.5; 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: 2 < R5 / R6 < 8.

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: 0.85 < f4 / f < 1.3; the curvature radius R7 of the object side of the fourth lens and the curvature radius R8 of the image side of the fourth lens satisfy: -2 < R7 / R8 < -1.

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: 1.3 < f5 / f < 2.2; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -4 < f6 / f < -1.

5.

9. 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: 4 < f7 / f < 15; the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 0.4 < R13 / R14 < 1.

10. The optical lens according to claim 1, characterized in that: The focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.15 < f1 / f2 < -0.

02.

11. The optical lens according to claim 1, characterized in that: The central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 0.2 < CT2 / CT3 < 0.4; the central thickness of the third lens and the central thickness CT4 of the fourth lens satisfy: 1.4 < CT3 / CT4 < 2.6.

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