Optical lens

Abstract

The present invention provides an optical lens having a total of four lenses, characterized in that, along the optical axis, from the object side to the imaging surface, the following are in order: a first lens with negative optical power, whose object side surface is convex and whose image side surface is concave; a second lens with negative optical power, whose object side surface is concave and whose image side surface is convex; an aperture stop; a third lens with positive optical power, whose object side surface and image side surface are both convex; and a fourth lens with positive optical power, whose object side surface is convex and whose image side surface is concave. The maximum field of view (FOV) and aperture value (FNO) of the optical lens satisfy the following conditions: 95°<FOV / FNO<105°.

Description

Technical Field

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

[0002] With the development of intelligent automobiles, the vehicle's assisted driving system has gradually improved. On-board laser radar is one of the main tools for the assisted driving system to obtain external information. The performance of the key component laser radar receiving lens directly affects the performance of the assisted driving system.

[0003] Existing automotive lidar receiving lenses have problems such as difficult lens manufacturing, high material and processing costs, unstable imaging quality that is easily affected by external environmental interference, generally small lens aperture that cannot clearly collect long-distance information, low edge signal-to-noise ratio of the imaging chip, and an overly lengthy structure that is not conducive to vehicle installation and use. Summary of the Invention

[0004] In view of the above problems, the purpose of the present invention is to provide an optical lens that can solve one or more of the above technical problems.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] An optical lens, comprising four lenses, characterized in that, along the optical axis from the object side to the imaging surface, the following are arranged in order:

[0007] a first lens having negative optical power, wherein the object-side surface is convex and the image-side surface is concave;

[0008] a second lens having negative optical power, whose object-side surface is concave and whose image-side surface is convex;

[0009] Aperture;

[0010] The third lens has positive optical power and its object-side and image-side surfaces are both convex;

[0011] a fourth lens element having positive optical power, with a convex object-side surface and a concave image-side surface;

[0012] The maximum field of view FOV and aperture value FNO of the optical lens satisfy the following conditions: 95°<FOV / FNO<105°.

[0013] Preferably, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle satisfy: TTL / IH<3.0.

[0014] Preferably, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field angle satisfy: 1.8<IH / f<2.2.

[0015] Preferably, the entrance pupil diameter EPD of the optical lens and the real image height IH corresponding to the maximum field angle satisfy: 2.3<IH / EPD<2.8.

[0016] Preferably, the effective focal length f, the maximum field of view FOV and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.55<(IH / 2) / (f×Tan(FOV / 2))<0.65.

[0017] Preferably, the optical back focus BFL of the optical lens and the effective focal length f satisfy: 0.65<BFL / f.

[0018] Preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -40.0<f2 / f<-5.0.

[0019] Preferably, the combined focal length f of the first lens and the second lens is 12 The combined focal length of the third lens and the fourth lens is f 34 Satisfies: -1.3<f 12 / f 34 <-0.9.

[0020] Preferably, the combined focal length f of the third lens and the fourth lens is 34 The center distance CT between the third lens and the fourth lens along the optical axis 34 Satisfaction: 0.45<CT 34 / f 34 <0.55.

[0021] Preferably, the sum of the total optical length TTL of the optical lens and the center thicknesses ΣCT of the first to fourth lenses along the optical axis respectively satisfies: 0.30<ΣCT / TTL<0.45.

[0022] Compared with the existing technology, the beneficial effects of the present invention are: by reasonably matching the lens shape and optical focal length of each lens, an optical lens is proposed, which achieves high-quality and high-stability imaging, can clearly collect long-distance information and improve the signal-to-noise ratio of edge field of view imaging, and minimize the size of the camera module.

[0023] Additional aspects and advantages of the present invention will be given in part in the description which follows and in part will be obvious from the description which follows, or may be learned through practice of the present invention. 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 of Example 1 of the present invention.

[0026] Figure 2 Graph showing the field curvature of the optical lens in Example 1 of the present invention.

[0027] Figure 3 2 is a graph showing the F-Tanθ distortion curve of the optical lens in Example 1 of the present invention.

[0028] Figure 4 This is a relative illumination curve diagram of the optical lens in Example 1 of the present invention.

[0029] Figure 5 This is the MTF curve of the optical lens in Example 1 of the present invention.

[0030] Figure 6 Schematic diagram of the structure of the optical lens of Example 2 of the present invention.

[0031] Figure 7 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0032] Figure 8 2 is a graph showing the F-Tanθ distortion curve of the optical lens in Example 2 of the present invention.

[0033] Figure 9 This is a relative illumination curve diagram of the optical lens in Example 2 of the present invention.

[0034] Figure 10 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

[0035] Figure 11 Schematic diagram of the structure of the optical lens of Example 3 of the present invention.

[0036] Figure 12 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0037] Figure 13 2 is a graph showing the F-Tanθ distortion curve of the optical lens in Example 3 of the present invention.

[0038] Figure 14 This is a relative illumination curve diagram of the optical lens in Example 3 of the present invention.

[0039] Figure 15 This is the MTF curve of the optical lens in Example 3 of the present invention.

[0040] Figure 16 Schematic diagram of the structure of the optical lens of Example 4 of the present invention.

[0041] Figure 174 is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0042] Figure 18 4 is an F-Tanθ distortion curve of the optical lens in Example 4 of the present invention.

[0043] Figure 19 This is a relative illumination curve diagram of the optical lens in Example 4 of the present invention.

[0044] Figure 20 This is the MTF curve of the optical lens in Example 4 of the present invention.

[0045] Figure 21 Schematic diagram of the structure of the optical lens of Example 5 of the present invention.

[0046] Figure 22 4 is a field curvature curve diagram of the optical lens in Example 5 of the present invention.

[0047] Figure 23 4 is an F-Tanθ distortion curve of the optical lens in Example 5 of the present invention.

[0048] Figure 24 This is a relative illumination curve diagram of the optical lens in Example 5 of the present invention.

[0049] Figure 25 This is the MTF curve of the optical lens in Example 5 of the present invention. DETAILED DESCRIPTION

[0050] For a better understanding of the present invention, various aspects of the present invention 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 the present invention and are not intended to limit the scope of the present invention in any way. Throughout this specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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. Furthermore, 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. Furthermore, when describing embodiments of the invention, "may" is used to mean "one or more embodiments of the invention." Furthermore, the term "exemplary" is intended to refer to an example or illustration.

[0055] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0056] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0057] The optical lens according to the embodiment of the present invention includes, from the object side to the image side, a first lens, a second lens, an aperture, a third lens, a fourth lens, and a filter.

[0058] In some embodiments, the first lens may have negative optical power, which helps reduce the inclination angle of the incident light, thereby effectively sharing the large object-side field of view. The object-side surface of the first lens is convex, and the image-side surface is concave, which helps to obtain a larger field of view angle range. In addition, in practical applications, considering the outdoor installation and use environment of automotive application lenses, the lens may be exposed to inclement weather such as rain and snow. Setting the first lens in a meniscus shape with the convex surface facing the object side can help water droplets slide off, reducing the impact on the lens imaging.

[0059] In some embodiments, the second lens element may have negative power, sharing the negative power of the front end of the optical lens, thereby helping to avoid excessive light deflection caused by the overly concentrated optical power of the first lens element. The second lens element has a concave object-side surface and a convex image-side surface, which improves light collection capabilities at the edge of the field of view while reducing the working aperture of the second lens element, thereby miniaturizing the rear end of the optical lens element.

[0060] In some embodiments, the third lens element may have positive optical power, which helps reduce light deflection angles and ensures a smooth transition of light. Both the object and image side surfaces of the third lens element are convex, facilitating a smooth transition of light and balancing the spherical aberration generated by the third lens element, thereby improving the imaging quality of the optical lens.

[0061] In some embodiments, the fourth lens element may have positive optical power, which facilitates a smooth transition of light and improves the imaging quality of the optical lens. The fourth lens element may have a convex object-side surface and a concave image-side surface, which improves the ability to focus light at the edges of the field of view while effectively controlling the overall optical length and reducing the size of the optical lens, thereby facilitating miniaturization of the optical lens.

[0062] In some embodiments, an aperture for limiting the light beam may be provided between the second lens and the third lens. The aperture may be provided near the image side surface of the second lens, which can reduce the generation of optical lens ghosts.

[0063] In some embodiments, the aperture value FNO of the optical lens satisfies: FNO<1.3. Meeting the above range can enable the optical lens to have a sufficiently large depth of field, allowing the optical lens to clearly acquire long-distance information.

[0064] In some embodiments, the maximum field of view (FOV) of the optical lens satisfies the following conditions: 120°≤FOV. Meeting the above range facilitates achieving wide-angle characteristics, thereby enabling the acquisition of more scene information and meeting the requirements of wide-range detection of the optical lens.

[0065] In some embodiments, the maximum field of view (FOV) and aperture value (FNO) of the optical lens satisfy the following conditions: 95° < FOV / FNO < 105°. Meeting this range not only allows the optical lens to have a sufficiently large depth of field, but also enables wide-angle characteristics to capture more scene information, meeting the requirements of long-distance, wide-range detection for the optical lens.

[0066] 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 (FOV) satisfy the following equation: TTL / IH < 3.0. Meeting this range facilitates achieving a balance between excellent imaging quality and compact design, meeting the requirements of optical lenses in confined working environments.

[0067] 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 satisfy the following conditions: 1.8 < IH / f < 2.2. Meeting this range enables both wide-angle performance, thus meeting the requirements of large-scale detection, and a large image plane, thereby improving the imaging quality of the optical system.

[0068] In some embodiments, the optical back focus (BFL) and effective focal length (f) of the optical lens satisfy the following relationship: 0.65 < BFL / f. Meeting this range helps strike a balance between good imaging quality and an optical back focus length that facilitates assembly, ensuring optical lens imaging quality while reducing the complexity of the camera module assembly process.

[0069] In some embodiments, the optical lens' entrance pupil diameter (EPD) and the true image height (IH) corresponding to the maximum field of view satisfy the following relationship: 2.3 < IH / EPD < 2.8. Meeting this range increases the width of the light beam entering the optical lens, improving brightness at the image plane and preventing vignetting, while also increasing the imaging area of the optical lens.

[0070] In some embodiments, the effective focal length f, maximum field of view (FOV), and true image height (IH) corresponding to the maximum field of view of the optical lens satisfy the following conditions: 0.55 < (IH / 2) / (f × Tan (FOV / 2)) < 0.65. Meeting these limits helps control optical lens distortion within a reasonable range, facilitating subsequent restoration using software algorithms.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens element satisfy the following conditions: -2.5 < f1 / f < -1.5. Meeting this range allows the first lens element to have an appropriate negative focal power, which helps reduce the inclination angle of the incident light, thereby effectively sharing the large object-side field of view and achieving a wider field of view angle range.

[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy the following: -40.0 < f2 / f < -5.0. Meeting this range allows the second lens to have an appropriate negative focal power, which can offset the negative focal power of the front end of the optical lens, thereby helping to avoid excessive light deflection caused by the overly concentrated focal length of the first lens.

[0073] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens element satisfy the following relationship: 2.0 < f3 / f < 3.0. Meeting this range allows the third lens element to have an appropriately positive focal power, which helps converge light while reducing the angle of light deflection, ensuring a smooth transition of light and improving the imaging quality of the optical lens.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens element satisfy the following: 1.5 < f4 / f < 2.5. Meeting this range allows the fourth lens element to have an appropriately positive focal power, which improves the ability to converge light in the peripheral field of view. It also effectively controls the overall optical length and reduces the size of the optical lens, thereby facilitating miniaturization of the optical lens.

[0075] In some embodiments, the combined focal length of the first lens and the second lens is f 12 The combined focal length of the third and fourth lenses is f 34 Satisfies: -1.3<f 12 / f 34 <-0.9. Meeting the above range can make the focal length distribution of the lens combination before and after the optical lens diaphragm similar, thereby improving the imaging quality of the optical lens.

[0076] In some embodiments, the object-side curvature radius R1 and the image-side curvature radius R2 of the first lens satisfy the following relationship: 1.5 < (R1 + R2) / (R1 - R2) < 2.5. Meeting this range effectively reduces the effect of field curvature generated by the first lens on the optical lens, thereby improving the imaging quality of the optical lens.

[0077] In some embodiments, the radius of curvature R2 of the image-side surface of the first lens element and the radius of curvature R3 of the object-side surface of the second lens element satisfy the following relationship: -0.85 < R2 / R3 < -0.65. Meeting this range allows the shapes of the image-side surface of the first lens element and the object-side surface of the second lens element to be controlled to be more symmetrical, effectively balancing the coma aberration of the optical lens element and improving the imaging quality of the optical lens element.

[0078] In some embodiments, the combined focal length of the third lens and the fourth lens is f 34 The center distance CT between the third lens and the fourth lens along the optical axis 34 Satisfaction: 0.45<CT 34 / f 34 <0.55. Meeting the above range can control the distribution of the lens position at the rear end of the optical lens aperture, which can compress the volume of the rear end of the optical lens, thereby facilitating the miniaturization of the optical lens.

[0079] In some embodiments, the total optical length TTL of the optical lens and the sum of the center thicknesses of the first through fourth lenses along the optical axis, ΣCT, satisfy the following condition: 0.30 < ΣCT / TTL < 0.45. Meeting this range effectively reduces the total length of the optical lens and facilitates its structural design and production process.

[0080] In order to make the system have better optical performance, multiple aspheric lenses are used in the lens, and the shape of each aspheric surface of the optical lens satisfies the following equation:

[0081]

[0082] Where z is the distance between the surface and the vertex 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, and A, B, C, D, E, and F are the second-order, fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients, respectively.

[0083] 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.

[0084] Example 1

[0085] See also Figure 1 , shown is a schematic structural diagram of the optical lens provided in Example 1 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, 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 negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0088] Aperture ST;

[0089] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0090] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0091] The filter G1 has an object side surface S9 and an image side surface S10 that are both flat surfaces;

[0092] The imaging surface S11 is a plane;

[0093] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0094] Table 1-1

[0095]

[0096] The surface parameters of the aspheric lens of the optical lens in Example 1 are shown in Table 1-2.

[0097] Table 1-2

[0098] Face number K A B C D E F S7 -1.11E+00 -2.08E-02 1.54E-04 4.94E-05 -7.66E-06 7.05E-07 -2.68E-08 S8 8.46E+00 -8.08E-02 1.19E-03 9.99E-05 -2.22E-05 1.93E-06 -7.25E-08

[0099] Figure 2 The following is a graph of field curvature for Example 1, showing the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the graph, the field curvature in both the meridional and sagittal image planes is controlled within ±0.06mm, demonstrating that the optical lens is capable of excellent correction of field curvature.

[0100] Figure 3 The following graph shows the F-Tanθ distortion curve for Example 1, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±50%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0101] Figure 4 A relative illumination curve for Example 1 is shown, showing relative illumination values at different field angles on the imaging plane. The horizontal axis represents the half field angle (unit: degrees), and the vertical axis represents the relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 70% at the maximum half field angle, indicating that the optical lens has excellent relative illumination.

[0102] Figure 5 A modulation transfer function (MTF) graph of Example 1 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.2 across the entire field of view. Within the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0103] Example 2

[0104] See also Figure 6 , shown is a schematic structural diagram of the optical lens provided in Example 2 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, and a filter G1.

[0105] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0106] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0107] Aperture ST;

[0108] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0109] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0110] The filter G1 has an object side surface S9 and an image side surface S10 that are both flat surfaces;

[0111] The imaging surface S11 is a plane;

[0112] The relevant parameters of each lens in the optical lens in Example 2 are shown in Table 2-1.

[0113] Table 2-1

[0114]

[0115] The surface parameters of the aspheric lens of the optical lens in Example 2 are shown in Table 2-2.

[0116] Table 2-2

[0117] Face number K A B C D E F S7 -1.29E+00 -2.34E-02 2.66E-04 3.21E-06 4.53E-07 9.00E-08 -7.97E-09 S8 1.49E+00 -1.17E-01 1.62E-03 -1.01E-04 7.29E-06 -2.08E-07 -1.28E-08

[0118] Figure 7 The following figure shows the field curvature curve of Example 2, which shows the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.06mm, demonstrating that the optical lens can excellently correct field curvature.

[0119] Figure 8 The following graph shows the F-Tanθ distortion curve for Example 2, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±50%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0120] Figure 9A relative illumination curve for Example 2 is shown, showing relative illumination values at different field angles on the imaging plane. The horizontal axis represents the half field angle (unit: degrees), and the vertical axis represents relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 80% at the maximum half field angle, indicating that the optical lens has excellent relative illumination.

[0121] Figure 10 A modulation transfer function (MTF) graph of Example 2 shows the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.2 across the entire field of view. Within the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0122] Example 3

[0123] See also Figure 11 , shown is a schematic structural diagram of the optical lens provided in Example 3 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, and a filter G1.

[0124] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0125] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0126] Aperture ST;

[0127] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0128] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0129] The filter G1 has an object side surface S9 and an image side surface S10 that are both flat surfaces;

[0130] The imaging surface S11 is a plane;

[0131] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0132] Table 3-1

[0133]

[0134]

[0135] The surface parameters of the aspheric lens of the optical lens in Example 3 are shown in Table 3-2.

[0136] Table 3-2

[0137] Face number K A B C D E F S7 -1.45E+00 -5.79E-02 8.45E-04 7.00E-06 -2.49E-06 3.45E-07 -1.96E-08 S8 -9.99E-01 -2.73E+00 -2.30E-02 -5.94E-04 3.76E-07 -6.04E-07 -2.94E-08

[0138] Figure 12 The following graph shows the field curvature curves for Example 3, which plot the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the graph, the field curvature in both the meridional and sagittal image planes is controlled within ±0.06mm, demonstrating that the optical lens is capable of excellent correction of field curvature.

[0139] Figure 13 The following graph shows the F-Tanθ distortion curve for Example 3, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±50%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0140] Figure 14 A relative illumination curve for Example 3 is shown, showing relative illumination values at different viewing angles on the imaging plane. The horizontal axis represents the half-viewing angle (unit: degrees), and the vertical axis represents the relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 80% at the maximum half-viewing angle, indicating that the optical lens has excellent relative illumination.

[0141] Figure 15 A modulation transfer function (MTF) graph of Example 3 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.2 across the entire field of view. Within the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0142] Example 4

[0143] See also Figure 16, shown is a schematic structural diagram of the optical lens provided in Example 4 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, and a filter G1.

[0144] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0145] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0146] Aperture ST;

[0147] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0148] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0149] The filter G1 has an object side surface S9 and an image side surface S10 that are both flat surfaces;

[0150] The imaging surface S11 is a plane;

[0151] The relevant parameters of each lens in the optical lens in Example 4 are shown in Table 4-1.

[0152] Table 4-1

[0153]

[0154] The surface parameters of the aspheric lens of the optical lens in Example 4 are shown in Table 4-2.

[0155] Table 4-2

[0156] Face number K A B C D E F S7 -1.54E+00 -5.90E-02 7.43E-04 -2.36E-06 -2.00E-06 2.99E-07 -1.77E-08 S8 -9.99E-01 -2.75E+00 -2.15E-02 -5.01E-04 -5.68E-07 -4.13E-07 -1.95E-08

[0157] Figure 17 The following graph shows the field curvature curves for Example 4, which plot the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the graph, the field curvature in both the meridional and sagittal image planes is controlled within ±0.06mm, demonstrating that the optical lens is capable of excellent correction of field curvature.

[0158] Figure 18The following graph shows the F-Tanθ distortion curve for Example 4, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±50%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0159] Figure 19 A relative illumination curve for Example 4 is shown, showing relative illumination values at different viewing angles on the imaging plane. The horizontal axis represents the half-viewing angle (unit: degrees), and the vertical axis represents the relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 80% at the maximum half-viewing angle, indicating that the optical lens has excellent relative illumination.

[0160] Figure 20 A modulation transfer function (MTF) graph of Example 4 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.1 across the entire field of view. Within the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0161] Example 5

[0162] See also Figure 21 , shown is a schematic structural diagram of the optical lens provided in Example 5 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, and a filter G1.

[0163] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0164] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0165] Aperture ST;

[0166] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0167] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0168] The filter G1 has an object side surface S9 and an image side surface S10 that are both flat surfaces;

[0169] The imaging surface S11 is a plane;

[0170] The relevant parameters of each lens in the optical lens in Example 5 are shown in Table 5-1.

[0171] Table 5-1

[0172]

[0173] The surface parameters of the aspheric lens of the optical lens in Example 5 are shown in Table 5-2.

[0174] Table 5-2

[0175] Face number K A B C D E F S7 -1.80E+02 4.10E-02 2.52E-03 -2.46E-04 1.62E-05 -4.26E-07 -6.40E-09 S8 -9.99E-01 -2.70E+00 -1.48E-02 -4.85E-04 3.07E-05 -2.29E-06 4.12E-08

[0176] Figure 22 The following is a graph of field curvature for Example 5, showing the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the graph, the field curvature in both the meridional and sagittal image planes is controlled within ±0.08mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0177] Figure 23 The following graph shows the F-Tanθ distortion curve for Example 5, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±50%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0178] Figure 24 A relative illumination curve for Example 5 is shown, showing relative illumination values at different viewing angles on the imaging plane. The horizontal axis represents the half-viewing angle (unit: degrees), and the vertical axis represents the relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 80% at the maximum half-viewing angle, indicating that the optical lens has excellent relative illumination.

[0179] Figure 25A modulation transfer function (MTF) curve for Example 5 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.1 across the entire field of view. Within the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0180] Please refer to Table 6, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture number FNO, true image height IH, field of view FOV of the optical lens, and the numerical values corresponding to each conditional expression in the above embodiments.

[0181] Table 6

[0182] Parameters and Conditionals Example 1 Example 2 Example 3 Example 4 Example 5 f(mm) 2.95 2.95 2.93 2.94 2.91 TTL(mm) 17.00 17.00 17.01 17.01 17.01 FNO 1.23 1.23 1.22 1.22 1.21 IH(mm) 6.04 6.03 6.05 6.04 6.05 EPD(mm) 2.40 2.40 2.40 2.40 2.40 FOV(°) 120.0 120.0 120.0 120.0 120.0 CRA(°) 7.02 7.28 7.05 7.01 7.14 TTL / IH 2.81 2.82 2.81 2.81 2.81 IH / f 2.05 2.04 2.06 2.06 2.08 BFL / f 0.68 0.68 0.68 0.68 0.69 IH / EPD 2.52 2.51 2.52 2.52 2.52 FOV / FNO(°) 97.61 97.59 98.29 98.07 99.11 (IH / 2) / (f×Tan(FOV / 2)) 0.59 0.59 0.60 0.59 0.60 <![CDATA[f1 / f]]> -1.93 -1.93 -1.79 -1.74 -1.82 <![CDATA[f2 / f]]> -34.26 -5.88 -8.76 -9.23 -9.40 <![CDATA[f3 / f]]> 2.78 2.39 2.27 2.35 2.30 <![CDATA[f4 / f]]> 2.15 1.97 2.24 2.19 2.26 <![CDATA[f 12 / f 34 ]]> -1.21 -0.94 -0.93 -0.92 -0.98 <![CDATA[(R1+R2) / (R1-R2)]]> 1.89 1.99 2.05 2.02 2.12 <![CDATA[R2 / R3]]> -0.82 -0.70 -0.75 -0.75 -0.80 <![CDATA[CT 34 / f 34 ]]> 0.52 0.46 0.53 0.53 0.51 ∑CT / TTL 0.36 0.42 0.36 0.36 0.40

[0183] In summary, the optical lens of the embodiment of the present invention proposes an optical lens by reasonably matching the lens shape and optical focal length of each lens, which achieves high-quality and high-stability imaging, can clearly collect long-distance information and improve the signal-to-noise ratio of edge field of view imaging, and minimize the size of the camera module.

[0184] 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.

[0185] 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 four lenses, characterized in that: Along the optical axis from the object side to the imaging surface: a first lens having negative optical power, wherein the object-side surface is convex and the image-side surface is concave; a second lens having negative optical power, whose object-side surface is concave and whose image-side surface is convex; Aperture; The third lens has positive optical power and its object-side and image-side surfaces are both convex; a fourth lens element having positive optical power, with a convex object-side surface and a concave image-side surface; The maximum field of view FOV and aperture value FNO of the optical lens satisfy the following conditions: 95°<FOV / FNO<105°.

2. The optical lens according to claim 1, wherein: The total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle satisfy the following: TTL / IH<3.

0.

3. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the real image height IH corresponding to the maximum field angle satisfy the following: 1.8<IH / f<2.

2.

4. The optical lens according to claim 1, wherein: The entrance pupil diameter EPD of the optical lens and the real image height IH corresponding to the maximum field angle satisfy the following: 2.3<IH / EPD<2.

8.

5. The optical lens according to claim 1, wherein: The effective focal length f, the maximum field of view FOV and the real image height IH corresponding to the maximum field of view of the optical lens satisfy the following conditions: 0.55<(IH / 2) / (f×Tan(FOV / 2))<0.

65.

6. The optical lens according to claim 1, wherein: The optical back focus BFL of the optical lens and the effective focal length f satisfy the following: 0.65<BFL / f.

7. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -40.0<f2 / f<-5.

0.

8. The optical lens according to claim 1, wherein: The combined focal length f of the first lens and the second lens 12 The combined focal length of the third lens and the fourth lens is f 34 Satisfies: -1.3<f 12 / f 34 <-0.

9.

9. The optical lens according to claim 1, wherein: The combined focal length f of the third lens and the fourth lens 34 The center distance CT between the third lens and the fourth lens along the optical axis 34 Satisfaction: 0.45<CT 34 / f 34 <0.

55.

10. The optical lens according to claim 1, wherein: The sum of the total optical length TTL of the optical lens and the center thicknesses ΣCT of the first to fourth lenses along the optical axis respectively satisfies the following: 0.30<ΣCT / TTL<0.45.

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