Optical lens

Abstract

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

Description

Technical Field

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

[0002] With the rapid development of fields such as drones, security, and automobiles, the pursuit of the imaging effect of the lenses carried by them has become more diversified. Currently, drones are developing rapidly and have won the favor of consumers with their unique high-altitude perspective and wide shooting range. Correspondingly, the demand for the optical lenses supporting them is also increasing. The optical lenses carried by them not only require high-definition image quality but also need to be able to present large local details, so as to achieve that the local details can be vividly shown even in the high-altitude view and capture close-up pictures of local areas.

[0003] Therefore, it is necessary to develop an optical lens with good imaging effect to better meet the market demand. Summary of the Invention

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

[0005] The present invention provides an optical lens, which has a total of seven lenses and sequentially includes, along the optical axis from the object side to the imaging surface:

[0006] The first lens with negative optical power, whose object side is convex and whose image side is concave;

[0007] The second lens with positive optical power, whose image side is convex;

[0008] The third lens with positive optical power, whose object side is convex and whose image side is convex;

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

[0010] The fifth lens with negative optical power, whose object side is concave and whose image side is concave near the optical axis;

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

[0012] The seventh lens with negative optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis;

[0013] Wherein, the maximum field of view FOV of the optical lens satisfies: 115° < FOV < 150°; the true image height IH corresponding to the maximum field of view of the optical lens, the maximum field of view FOV of the optical lens and the effective focal length f of the optical lens satisfy: 43° < (f × FOV) / IH < 50°.

[0014] 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 < -1.2; 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: 2.5 < R1 / R2 < 5.

[0015] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.8 < f2 / f < 2.8; the effective focal length f of the optical lens and the curvature radius R4 of the image side surface of the second lens satisfy: -2 < R4 / f < -0.5.

[0016] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.3 < f3 / f < 2; the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.7 < f4 / f < 2.7.

[0017] Further preferably, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: 0.4 < f3 / f4 < 1.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.5 < f5 / f < -1; the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -2.5 < f5 / f6 < -1.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.5 < f6 / f < 0.85.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -1.2 < f7 / f < -0.7.

[0021] Further preferably, the overall optical length TTL of the optical lens and the back focal length BFL of the optical lens satisfy: 0.18 < BFL / TTL < 0.25; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.45 < BFL / f < 0.6.

[0022] Further preferably, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 1.1 < f1 / f7 < 2; the clear aperture DM11 of the object side surface of the first lens and the clear aperture DM72 of the image side surface of the seventh lens satisfy: 0.5 < DM11 / DM72 < 0.65.

[0023] Further preferably, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.2 < IH / f < 3.2; 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: 0.83 < TTL / IH < 0.93.

[0024] Compared with the prior art, the optical lens provided by the present invention uses seven lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, making the lens have one or more advantages such as a large wide angle, miniaturization, and high imaging quality. Brief Description of the Drawings

[0025] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0026] Figure 1 It is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 2 It is a field curvature curve graph of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 3 It is an MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 4 It is an axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 5 It is a lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 6 It is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 7 It is a field curvature curve graph of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 8 It is an MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 9 It is an axial aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 10 It is a lateral chromatic aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0036] Figure 11This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 12 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 13 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0039] Figure 14 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 15 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0041] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0042] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0043] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0044] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0045] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0046] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0047] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0048] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0049] The optical lens provided in this embodiment of the invention comprises seven lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane as follows: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0050] In some embodiments, the first lens may have negative optical power, with a convex object-side surface and a concave image-side surface. The second lens may have positive optical power, with either a concave or convex object-side surface and a convex image-side surface. The third lens may have positive optical power, with both a convex object-side surface and a convex image-side surface. The fourth lens may have positive optical power, with both a convex object-side surface near the optical axis and a convex image-side surface. The fifth lens may have negative optical power, with both a concave object-side surface and a concave image-side surface near the optical axis. The sixth lens may have positive optical power, with both a concave object-side surface and a convex image-side surface. The seventh lens may have negative optical power, with both a convex object-side surface near the optical axis and a concave image-side surface near the optical axis.

[0051] In some embodiments, the optical lens may also include an aperture stop, which may be located between the second lens and the third lens. It is understood that the aperture stop is used to limit the amount of light entering the lens to change the brightness of the image. When the aperture stop is located between the second and third lenses, it facilitates the correction of aperture aberrations.

[0052] In some embodiments, the optical lens may further include a filter 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.

[0053] In some embodiments, the maximum field of view (FOV) of the optical lens satisfies: 115° < FOV < 150°. Meeting the above conditions is beneficial to achieving the ultra-wide-angle characteristic, so as to obtain more scene information and meet the requirements of large-range detection of the optical lens.

[0054] In some embodiments, the true image height (IH) corresponding to the maximum field of view of the optical lens, the maximum field of view (FOV) of the optical lens, and the effective focal length (f) of the optical lens satisfy: 43° < (f × FOV) / IH < 50°. Meeting the above conditions is beneficial to achieving the balance between the large field of view and large target surface imaging of the optical lens by reasonably restricting the relationship between the focal length, field of view, and image height of the optical lens.

[0055] 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 < -1.2. Meeting the above conditions can make the first lens have a large negative refractive power, avoid the over-concentration of negative optical power, and at the same time is beneficial to increasing the field of view, and is beneficial to collecting as much marginal field light as possible into the rear optical lens to achieve large-angle light collection.

[0056] 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: 2.5 < R1 / R2 < 5. Meeting the above conditions can effectively control the meniscus surface shape of the first lens, and is beneficial to increasing the field of view while controlling the front aperture of the optical lens to achieve the balance between large field of view and miniaturization.

[0057] In some embodiments, the effective focal length (f) of the optical lens and the focal length (f2) of the second lens satisfy: 1.8 < f2 / f < 2.8. Meeting the above conditions can effectively converge the large-range light entering the system, and is beneficial to avoiding excessive light deflection caused by the over-concentration of the optical power of the first lens and reducing the difficulty of aberration correction.

[0058] In some embodiments, the effective focal length (f) of the optical lens and the curvature radius (R4) of the image side surface of the second lens satisfy: -2 < R4 / f < -0.5. Meeting the above conditions can effectively converge the large-range light entering the system, and at the same time is beneficial to the rear optical system to correct the large-angle aberration, so as to achieve the balance between the miniaturization and high pixel of the optical lens.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.3 < f3 / f < 2. Meeting the above conditions, by reasonably setting the focal length of the third lens, it is beneficial to the smooth transition of light, facilitating the correction of astigmatism and field curvature, 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 f4 of the fourth lens satisfy: 1.7 < f4 / f < 2.7. 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, improving the imaging quality of the optical lens.

[0061] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: 0.4 < f3 / f4 < 1. Meeting the above conditions is conducive to allowing the diverging light to smoothly enter the rear optical system, reducing the difficulty of correcting field curvature and distortion, and improving the overall resolution.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.5 < f5 / f < -1. Meeting the above conditions can give the fifth lens a large negative optical power, which is beneficial to diverging the light converged by the third lens and the fourth lens, and increasing the image height of the optical lens.

[0063] In some embodiments, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -2.5 < f5 / f6 < -1. Meeting the above conditions is beneficial to the smooth transition of light, and at the same time correcting various aberrations of the optical lens, improving the imaging quality of the optical lens.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.5 < f6 / f < 0.85; 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: 1.1 < (R11 + R12) / (R11 - R12) < 1.35. Meeting the above conditions can control the contribution of spherical aberration of the sixth lens within a reasonable range, enabling the lens to have a high axial imaging resolution ability, which is beneficial to achieving high-definition imaging of the lens.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -1.2 < f7 / f < -0.7. Meeting the above conditions is beneficial to increasing the degree of divergence of light, 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.

[0066] In some embodiments, the total optical length TTL of the optical lens and the back focal length BFL of the optical lens satisfy: 0.18 < BFL / TTL < 0.25; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.45 < BFL / f < 0.6. Meeting the above conditions can make the lens have an appropriate back focus, ensure the compatibility between the lens and the body, and make the structure of the lens more compact.

[0067] In some embodiments, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 1.1 < f1 / f7 < 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 surface imaging of the lens.

[0068] In some embodiments, the light entrance diameter DM11 of the object side of the first lens and the light exit diameter DM72 of the image side of the seventh lens satisfy: 0.5 < DM11 / DM72 < 0.65. Meeting the above conditions, while ensuring that light within a large range enters the system, the diameter size of the lens is effectively reduced, which is beneficial to achieving the balance of large field of view and small aperture of the lens.

[0069] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.2 < IH / f < 3.2. 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 surface characteristic to improve the imaging quality of the optical lens.

[0070] 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: 0.83 < TTL / IH < 0.93. Meeting the above conditions can better achieve the miniaturization of the lens. At the same time, when ensuring the same total length of the lens, it has a larger image surface and can match a larger-size imaging chip to achieve high-definition imaging.

[0071] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f satisfy: 2 < TTL / f < 3. Meeting the above conditions can effectively limit the length of the lens, which is beneficial to achieving the miniaturization of the optical lens.

[0072] In some embodiments, 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: -0.5 < R5 / R6 < -0.005; 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: -10 < R7 / R8 < -1. Meeting the above conditions is beneficial to better achieving the convergence of light, shortening the distance of light reaching the next lens, and thus reducing the total length of the optical lens.

[0073] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -2 < R9 / R10 < -1.2. By satisfying the above conditions, the light rays converged by the front lens can be diverged so that they can reach a higher imaging position, appropriately拉开 the optical path lengths of the light rays in each field of view, and gently diverge them to the rear lens system.

[0074] In some embodiments, 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: 1.5 < (R13 + R14) / (R13 - R14) < 2. By satisfying the above conditions, the angle of incidence of the marginal field of view on the imaging surface can be appropriately suppressed, and more light beams can be effectively transmitted to the imaging surface, improving the relative illumination of the optical lens.

[0075] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6 < IH / EPD < 8. By satisfying the above conditions, the width of the light beam incident on the optical lens can be increased, so that the brightness of the optical lens at the image plane is improved and vignetting is avoided.

[0076] In some embodiments, the optical lens satisfies the conditional formula: 2mm < f < 3mm, 5mm < TTL < 7mm, 6mm < IH < 7.5mm, 36° < CRA < 40°, where f represents the effective focal length of the optical lens, TTL represents the total optical length of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, and CRA represents the principal ray angle of incidence of the optical lens. By satisfying the above conditions, it shows that the optical lens provided by the embodiments of the present invention at least has the characteristics of a large image plane and miniaturization, and can match an imaging chip with a larger CRA to achieve high-definition imaging.

[0077] In some embodiments, the seven lenses in the optical lens can all be made of plastic lenses or adopt a structure with a combination of glass and plastic materials. Preferably, the optical lens of the present invention adopts a structure of seven lenses with a combination of glass and plastic, which can enable the optical lens to better match a large target surface chip to achieve high-definition imaging, and at the same time can also achieve a reasonable balance of miniaturization, large image plane and large wide angle of the optical lens. Specifically, the second lens can be made of a glass lens, and the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all plastic lenses; adopting a combination structure of glass and plastic can effectively reduce costs, correct aberrations, reduce volume, and provide an optical lens product with higher cost performance.

[0078] In some embodiments, the first, second, third, fourth, fifth, sixth, and seventh lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, in the optical lens provided by this invention, the second lens can be a spherical lens, while the first, third, fourth, fifth, sixth, and seventh lenses can be aspherical lenses.

[0079] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations:

[0080]

[0081] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, and H are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0082] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0083] Example 1

[0084] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging surface S17, the following components in sequence: a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a filter G1.

[0085] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0086] The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is convex.

[0087] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex.

[0088] The fourth lens L4 has positive optical power, its object side S7 is convex near the optical axis, and its image side S8 is convex.

[0089] The fifth lens L5 has negative optical power, its object side S9 is concave, and its image side S10 is concave near the optical axis.

[0090] The sixth lens L6 has positive optical power, its object side S11 is concave, and its image side S12 is convex.

[0091] The seventh lens L7 has negative optical power. Its object side S13 is convex near the optical axis, and its image side S14 is concave near the optical axis.

[0092] The object-side surface S15 and the image-side surface S16 of filter G1 are both planar.

[0093] The imaging plane S17 is a plane.

[0094] The second lens L2 is a glass spherical lens; the first lens L1, 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.

[0095] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0096] Table 1-1

[0097]

[0098]

[0099] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0100] Table 1-2

[0101]

[0102] In this embodiment, the field curvature curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0103] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the field curvature of light rays in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.15 mm, indicating that the optical lens 100 can effectively correct the field curvature.

[0104] Figure 3 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.6 throughout the entire field of view. Within the range of 0–100 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0105] Figure 4 The axial aberration curve of Embodiment 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within ±0.04 mm, indicating that the optical lens 100 can effectively correct axial aberration.

[0106] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2.5 μm, indicating that the optical lens 100 can effectively correct transverse chromatic aberration.

[0107] Example 2

[0108] Please see Figure 6 The figure shown is a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

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

[0110] Table 2-1

[0111]

[0112]

[0113] The surface profile parameters of the aspherical 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 field curvature curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0117] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.2mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0118] from Figure 8 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 100 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. The optical lens 200 has good imaging quality and good detail resolution in both low and high frequency conditions.

[0119] from Figure 9 As can be seen, the axial aberration offset is controlled within ±0.04mm, indicating that the optical lens 200 can correct axial aberration well.

[0120] from Figure 10 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±3.5μm, indicating that the optical lens 200 can effectively correct transverse chromatic aberration.

[0121] Example 3

[0122] Please see Figure 11 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S3 of the second lens L2 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface 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 profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0127] Table 3-2

[0128]

[0129]

[0130] In this embodiment, the field curvature curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0131] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.1mm, indicating that the optical lens 300 can effectively correct field curvature.

[0132] from Figure 13 As can be seen, the MTF value of this embodiment is above 0.65 throughout the entire field of view. In the range of 0 to 100 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. The optical lens 300 has good imaging quality and good detail resolution in both low and high frequency conditions.

[0133] from Figure 14 As can be seen, the axial aberration offset is controlled within ±0.03mm, indicating that the optical lens 300 can correct axial aberration well.

[0134] from Figure 15 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens 300 can effectively correct transverse chromatic aberration.

[0135] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0136] Table 4

[0137]

[0138]

[0139] Compared with the prior art, the optical lens provided by the present invention has at least the following advantages:

[0140] The optical lens provided by this invention adopts a seven-element glass-plastic hybrid structure. Through specific surface shape settings and reasonable optical power distribution, the structure of the optical lens is relatively compact, enabling a large field of view and a large image plane for high-definition imaging. At the same time, it can also reasonably correct the overall aberration of the optical lens, giving it high pixel count while effectively shortening its overall length, thus better meeting the needs of drones for miniaturization, large image plane, and wide-angle shooting.

[0141] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0142] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging plane along the optical axis, successively comprises: a first lens with negative refractive power, the object side of which is convex, and the image side of which is concave; a second lens with positive refractive power, the image side of which is convex; a third lens with positive refractive power, the object side of which is convex, and the image side of which is convex; a fourth lens with positive refractive power, the object side of which is convex near the optical axis, and the image side of which is convex; a fifth lens with negative refractive power, the object side of which is concave, and the image side of which is concave near the optical axis; a sixth lens with positive refractive power, the object side of which is concave, and the image side of which is convex; a seventh lens with negative refractive power, the object side of which is convex near the optical axis, and the image side of which is concave near the optical axis; wherein the maximum field of view FOV of the optical lens satisfies: 115°<FOV<150°; the real image height IH corresponding to the maximum field of view FOV of the optical lens, the maximum field of view FOV of the optical lens and the effective focal length f of the optical lens satisfy: 43°<(f×FOV) / IH<50°; the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.8<f2 / f<2.8; and the effective focal length f of the optical lens and the image side surface curvature radius R4 of the second lens satisfy: -2<R4 / f<-0.

5.

2. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.8<f1 / f<-1.2; and the object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: 2.5<R1 / R2<5.

3. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6<IH / EPD<8.

4. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.3<f3 / f<2; and the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.7<f4 / f<2.

7.

5. The optical lens of claim 1, wherein, The focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: 0.4<f3 / f4<1.

6. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.5<f5 / f<-1; and the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -2.5<f5 / f6<-1.

7. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.5<f6 / f<0.

85.

8. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -1.2<f7 / f<-0.

7.

9. The optical lens of claim 1, wherein, The total optical length TTL of the optical lens and the back focal length BFL of the optical lens satisfy: 0.18<BFL / TTL<0.25; and the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.45<BFL / f<0.

6.

10. The optical lens of claim 1, wherein, A focal length f1 of the first lens and a focal length f7 of the seventh lens satisfy: 1.1 < f1 / f7 < 2; an object-side light entrance aperture DM11 of the first lens and an image-side light entrance aperture DM72 of the seventh lens satisfy: 0.5 < DM11 / DM72 < 0.

65.

11. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a real image height IH corresponding to a maximum field angle of the optical lens satisfy: 2.2 < IH / f < 3.2; an optical total length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.83 < TTL / IH < 0.93.

Images