Optical lens

Abstract

The invention provides an optical lens, which comprises nine lenses from an object side to an imaging surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, 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 concave surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; the sixth lens has negative focal power; the seventh lens has positive focal power; the eighth lens has positive focal power; and the ninth lens has positive focal power. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of short focus, miniaturization, large field angle, large aperture, large target surface, low distortion and low sensitivity.

Description

Technical Field

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

[0002] With the rapid development of drones, security, automotive, meteorology, medical, VR, AR and other fields, the requirements for the field of view of the lenses they carry are becoming increasingly higher. Wide-angle lenses introduce barrel distortion to compress the light at the edge of the field of view as much as possible, thus achieving ultra-wide-angle lenses. Currently, ultra-wide-angle lenses still have many problems. For example, the aperture of common ultra-wide-angle lenses is relatively small, resulting in insufficient light entering the lens and unclear images in dark environments. In addition, there are problems such as difficulty in correcting aberrations, large distortion, and loss of focus in high and low temperature environments. Summary of the Invention

[0003] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0004] The present invention provides an optical lens, comprising nine lenses, which include the following lenses in order from the object side to the imaging surface along the optical axis: The first lens has a negative optical power, its object-side surface is convex and its image-side surface is concave; a second lens having negative optical power, the object-side surface of which is convex and the image-side surface of which is concave; a third lens element having positive optical power, whose object-side surface is convex and whose image-side surface is concave; a fourth lens element having positive refractive power, whose object-side surface is concave and whose image-side surface is convex; a fifth lens element having positive refractive power, whose object-side surface and image-side surface are convex; a sixth lens element having negative optical power and a concave image-side surface; a seventh lens element having positive refractive power and a convex image-side surface; An eighth lens element having positive refractive power, whose object-side surface is convex near the optical axis and whose image-side surface is concave; The ninth lens element has positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis; The real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy the following conditions: 3.7 <IH / f<3.9。

[0005] Further preferably, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens meet the following requirements: 7mm <TTL / Fno<9.1mm。

[0006] Further preferably, the maximum field of view FOV of the optical lens and the chief ray incidence angle CRA at the maximum image height of the optical lens meet the following conditions: 3.8 <FOV / CRA<5.6。

[0007] Further preferably, the total optical length TTL of the optical lens and the sum ΣCT of the center thicknesses of the first lens to the ninth lens along the optical axis respectively satisfy: 1.4 <TTL / ∑CT<1.8。

[0008] Further preferably, the object side light semi-aperture CSD31 of the third lens and the object side light semi-aperture sag SAG31 of the third lens meet the following conditions: 2.3 <CSD31 / SAG31<2.9。

[0009] Further preferably, the focal length f1 of the first lens, the curvature radius R1 of the object side surface of the first lens, and the curvature radius R2 of the image side surface of the first lens satisfy: -0.45 <f1 / (R1+R2)<-0.25。

[0010] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 3.1 <f7 / f<8.7。

[0011] Further preferably, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 20 <f8 / f<50。

[0012] Further preferably, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -0.97 <f5 / f6<-0.94。

[0013] Further preferably, the focal length f3 of the third lens, the focal length f4 of the fourth lens, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy the following relationship: 8<(f3+f4+f5) / f<13.

[0014] Compared with the existing technology, the optical lens provided by the present invention uses nine lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages of short focus, miniaturization, large field of view, large aperture, large target surface, low distortion, and low sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which: Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0016] Figure 2 Graph showing the F-Theta distortion of the optical lens in Example 1 of the present invention.

[0017] Figure 3 Graph showing the field curvature of the optical lens in Example 1 of the present invention.

[0018] Figure 4 Graph showing the vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0019] Figure 5 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0020] Figure 6 Graph showing the F-Theta distortion of the optical lens in Example 2 of the present invention.

[0021] Figure 7 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0022] Figure 8 Graph showing vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0023] Figure 9 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0024] Figure 10 Graph showing the F-Theta distortion of the optical lens in Example 3 of the present invention.

[0025] Figure 11 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0026] Figure 12 Graph showing vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0027] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0028] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of embodiments of the present application and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] It should also be understood that the terms "comprises," "including," "having," "includes," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application." And, the term "exemplary" is intended to refer to an example or illustration.

[0033] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application 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.

[0034] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this 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.

[0035] The optical lens provided by the embodiment of the present invention has a total of nine lenses. The optical lens sequentially includes, along the optical axis from the object side to the imaging surface: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens.

[0036] In some embodiments, the first lens may have a negative optical power, its object side surface is convex, and its image side surface is concave. The second lens may have a negative optical power, its object side surface is convex, and its image side surface is concave. The third lens may have a positive optical power, its object side surface is convex, and its image side surface is concave. The fourth lens may have a positive optical power, its object side surface is concave, and its image side surface is convex. The fifth lens may have a positive optical power, its object side surface is convex, and its image side surface is convex. The sixth lens may have a negative optical power, its object side surface may be concave or convex, and its image side surface is concave. The seventh lens may have a positive optical power, its object side surface may be concave or convex, and its image side surface is convex. The eighth lens may have a positive optical power, its object side surface is convex near the optical axis, and its image side surface is concave. The ninth lens may have a positive optical power, its object side surface is convex near the optical axis, and its image side surface is concave near the optical axis.

[0037] In some embodiments, the optical lens may further include an aperture, and the aperture may be located between the fourth lens and the fifth lens. It can be understood that the aperture is used to limit the amount of incident light to change the brightness of the image. When the aperture is located between the fourth lens and the fifth lens, it is convenient for correcting the aperture aberration.

[0038] In some embodiments, the optical lens may further include a filter, and the filter is disposed between the ninth 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.

[0039] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 3.7 < IH / f < 3.9. By satisfying the above conditional formula, controlling the ratio of the effective focal length to the image height of the optical lens, shortening the effective focal length can expand the field angle, enabling the optical lens to capture a wider object-side space, and at the same time enabling the optical lens to match a chip with a large image surface, improving the imaging quality of the optical lens.

[0040] In some embodiments, the overall optical length TTL of the optical lens and the F-number Fno of the optical lens satisfy: 7mm < TTL / Fno < 9.1mm. By satisfying the above conditional formula, by controlling the relationship between the overall length and the F-number of the optical lens, it is ensured that the optical lens can meet the requirements of large aperture and miniaturization design, enabling the optical lens to obtain sufficient light transmission in a dim environment and meeting the needs of high-quality and high-definition shooting.

[0041] In some embodiments, the maximum field of view (FOV) of the optical lens and the chief ray angle of incidence (CRA) at the maximum image height of the optical lens satisfy: 3.8 < FOV / CRA < 5.6. By satisfying the above conditional expression, incident light rays at different field angles of the optical lens can enter the image sensor at appropriate angles, thereby improving the photosensitive performance of the image sensor and enhancing the imaging quality of the optical lens.

[0042] In some embodiments, the total optical length (TTL) of the optical lens and the sum (∑CT) of the central thicknesses of the first lens to the ninth lens along the optical axis satisfy: 1.4 < TTL / ∑CT < 1.8. By satisfying the above conditional expression, reasonably configuring the total optical length of the optical lens and the sum of the thicknesses of each lens helps to achieve high pixel characteristics and improve the imaging quality of the optical lens; at the same time, it can effectively shorten the total optical length of the optical lens to meet the requirements of miniaturization and lightweight design.

[0043] In some embodiments, the clear aperture semi-diameter (CSD31) of the object side surface of the third lens and the sagitta (SAG31) of the clear aperture semi-diameter of the object side surface of the third lens satisfy: 2.3 < CSD31 / SAG31 < 2.9. By satisfying the above conditional expression, by adjusting the surface shape of the edge region of the object side surface of the third lens, the ghost reflection energy can be reduced and the field curvature can be optimized, enhancing the imaging quality of the optical lens.

[0044] In some embodiments, the focal length (f1) of the first lens, the curvature radius (R1) of the object side surface of the first lens, and the curvature radius (R2) of the image side surface of the first lens satisfy: -0.45 < f1 / (R1 + R2) < -0.25. By satisfying the above conditional expression, the surface shapes of the object side surface and the image side surface of the first lens can be constrained, which is beneficial to reducing the bending degree of light rays at the image side surface of the first lens and decreasing the astigmatism of the optical lens to balance the astigmatism problem brought by the large field angle of the optical lens, so that while the optical lens has a large field of view, the astigmatism is not too large, thereby ensuring that the optical lens has excellent imaging quality.

[0045] In some embodiments, the effective focal length (f) of the optical lens and the focal length (f7) of the seventh lens satisfy: 3.1 < f7 / f < 8.7. By satisfying the above conditional expression, reasonably controlling the focal length value of the seventh lens makes the light ray trend gentle, which is beneficial to the divergence of light rays while achieving the apochromatic function and is beneficial to ensuring the tolerance performance.

[0046] In some embodiments, the effective focal length (f) of the optical lens and the focal length (f8) of the eighth lens satisfy: 20 < f8 / f < 50. By satisfying the above conditional expression, setting the second last lens of the optical lens to have a positive optical power is beneficial to the gentle transition of light rays, correcting chromatic aberration, enhancing the resolution ability of the optical lens, and improving the imaging quality.

[0047] In some embodiments, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -0.97 < f5 / f6 < -0.94. By satisfying the above conditional formula, the effective focal lengths of the fifth lens and the sixth lens are restricted, which can effectively correct the spherical aberration and axial chromatic aberration of the optical lens, improve the resolution of the optical lens; it can also better achieve the characteristic of eliminating temperature drift, contribute to the thermal compensation of the optical lens, and thus enable the optical lens to have good temperature performance.

[0048] In some embodiments, the focal length f3 of the third lens, the focal length f4 of the fourth lens, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 8 < (f3 + f4 + f5) / f < 13. By satisfying the above conditional formula, the depth of field of the optical lens can be effectively controlled, making the depth of field of the short focal length optical lens larger, enabling objects within a larger range to remain relatively clear, and at the same time effectively eliminating chromatic aberration.

[0049] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1.2 < f5 / f < 2.3. By satisfying the above conditional formula, sufficient positive optical power is configured in the middle of the optical lens, which is beneficial to controlling the angle of light, improving the photosensitive performance of the photosensitive element, and enhancing the resolution; at the same time, it is also beneficial to correcting the aberration generated by the refraction of light by the front lens and ensuring the imaging quality.

[0050] In some embodiments, the central thickness CT1 of the first lens, the central thickness CT2 of the second lens, the central thickness CT3 of the third lens, the central thickness CT4 of the fourth lens and the overall optical length TTL of the optical lens satisfy: 0.32 < (CT1 + CT2 + CT3 + CT4) / TTL < 0.42. By satisfying the above conditional formula, the relationship between the overall length of the optical lens and the thickness of some lenses can be effectively controlled, and it can be ensured that the thickness tolerance of the optical lens has a low sensitivity, improving the assembly yield.

[0051] In some embodiments, the sagittal height SAG11 of the object side light-passing semi-aperture of the first lens and the central thickness CT1 of the first lens satisfy: 0.7 < SAG11 / CT1 < 2.3. By satisfying the above conditional formula, controlling the ratio of the sagittal height of the object side of the first lens to the central thickness of the first lens on the optical axis can make the surface shape of the object side tend to be curved and the sagittal height larger, which is conducive to the first lens collecting large-field light, achieving high angular resolution at the center of the optical lens, and thus improving the imaging quality of the central region.

[0052] In some embodiments, the effective focal length f of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.4 < f / EPD < 1.9. By satisfying the above conditional formula, by controlling the ratio of the effective focal length of the optical lens to the entrance pupil diameter, it helps to improve the light receiving ability of the optical lens, obtain as much object space information as possible, and thus obtain imaging information with higher brightness and resolution.

[0053] In some embodiments, the optical lens satisfies the following conditional formula: 1.2 mm < f < 1.6 mm; 150° ≤ FOV < 220°; 0.8 mm < EPD < 1 mm; 12 mm < TTL < 13.5 mm; 1.4 < Fno < 1.9; 4.8 mm < IH < 6 mm; where f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the f-number of the optical lens, and IH represents the image height corresponding to the maximum field of view angle of the optical lens. By satisfying the above conditional formula, the optical lens has at least one or more advantages of short focal length, large field of view angle, large entrance pupil diameter, short total length, large aperture, large target surface, low distortion, and low sensitivity.

[0054] 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. On the other hand, when the lens material is glass, due to the low dispersion characteristic of the glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. In the optical lens provided by the present invention, the first lens and the fourth lens can be made of glass material, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens can be made of plastic material. By adopting a glass-plastic hybrid structure, the cost can be effectively reduced, the aberration can be corrected, the volume can be reduced, the thermal stability performance can be improved, and an optical lens product with higher cost performance can be provided.

[0055] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens and the fourth lens of the present invention adopt spherical lenses; the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens adopt aspherical lenses.

[0056] In each embodiment of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations: ; 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 B, C, D, E, F, G, H, I, and J are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order, eighteenth-order, and twentieth-order surface coefficients, respectively.

[0057] 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.

[0058] Example 1 See also Figure 1 , shown is a schematic structural diagram of the optical lens 100 provided in Example 1 of the present invention. The optical lens 100 includes, in order from the object side to the imaging surface S21 along the optical axis: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a filter G1.

[0059] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave; The second lens L2 has negative refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave; The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave; The fourth lens L4 has positive refractive power, its object-side surface S7 is concave, and its image-side surface S8 is convex; The fifth lens L5 has positive refractive power, its object-side surface S9 is convex, and its image-side surface S10 is convex; The sixth lens L6 has negative refractive power, its object-side surface S11 is convex near the optical axis, and its image-side surface S12 is concave; The seventh lens L7 has positive refractive power, its object-side surface S13 is convex, and its image-side surface S14 is convex; The eighth lens L8 has positive refractive power, its object-side surface S15 is convex near the optical axis, and its image-side surface S16 is concave; The ninth lens L9 has positive refractive power, its object-side surface S17 is convex at the near optical axis, and its image-side surface S18 is concave at the near optical axis; The object-side surface S19 and the image-side surface S20 of the filter G1 are both flat surfaces; The imaging surface S21 is a plane.

[0060] The first lens L1 and the fourth lens L4 are glass spherical lenses; the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are plastic aspherical lenses.

[0061] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0062] Table 1-1 The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0063] Table 1-2 In this embodiment, the F-Theta distortion curve, field curvature curve, and vertical axis chromatic aberration curve of the optical lens 100 are shown in FIG. Figure 2 、 Figure 3 、 Figure 4 shown.

[0064] Figure 2 The following figure shows the F-Theta distortion curve of the optical lens 100 in this embodiment, which represents the distortion at different field angles on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the distortion value is controlled within 0-20%, indicating that the optical lens 100 is able to correct distortion well.

[0065] Figure 3 A field curvature graph of the optical lens 100 in this embodiment is shown, showing the field curvature of light 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 the meridional and sagittal image planes is controlled within ±0.05mm, indicating that the optical lens 100 can effectively correct field curvature.

[0066] Figure 4 A graph showing vertical chromatic aberration of the optical lens 100 in this embodiment shows the chromatic aberration of each wavelength relative to the central wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for the longest and shortest wavelengths is controlled within a range of -1 μm to 3 μm, indicating that the optical lens 100 is able to effectively correct vertical chromatic aberration.

[0067] Example 2 See also Figure 5, shown is a schematic structural diagram of an optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the object-side surface S11 of the sixth lens L6 is a concave surface; the object-side surface S13 of the seventh lens L7 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0068] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0069] Table 2-1 The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0070] Table 2-2 In this embodiment, the F-Theta distortion curve, field curvature curve, and vertical axis chromatic aberration curve of the optical lens 200 are shown in FIG. Figure 6 、 Figure 7 、 Figure 8 shown.

[0071] from Figure 6 It can be seen from the figure that the distortion value is controlled within 0-50%, indicating that the optical lens 200 can correct the distortion well.

[0072] from Figure 7 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.05 mm, indicating that the optical lens 200 can correct the field curvature well.

[0073] from Figure 8 It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm~5μm, indicating that the optical lens 200 can better correct the vertical axis chromatic aberration.

[0074] Example 3 See also Figure 9 , shown is a schematic structural diagram of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main difference between this embodiment is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0075] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0076] Table 3-1 The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0077] Table 3-2 In this embodiment, the F-Theta distortion curve, field curvature curve, and vertical axis chromatic aberration curve of the optical lens 300 are shown in FIG. Figure 10 、 Figure 11 、 Figure 12 shown.

[0078] from Figure 10 It can be seen that the distortion value is controlled within 0~20%, indicating that the optical lens 300 can correct the distortion well.

[0079] from Figure 11 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.05mm~0.06mm, indicating that the optical lens 300 can correct the field curvature well.

[0080] from Figure 12 It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm~4μm, indicating that the optical lens 300 can better correct the vertical axis chromatic aberration.

[0081] Please refer to Table 4, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, real image height IH corresponding to the maximum field of view angle, chief ray incidence angle CRA at the maximum image height, maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0082] Table 4 In summary of the above embodiments, the optical lens provided by the present invention uses nine lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages of short focus, miniaturization, large field of view, large aperture, large target surface, low distortion, and low sensitivity.

[0083] 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.

[0084] 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 nine lenses, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: The first lens has a negative optical power, its object-side surface is convex and its image-side surface is concave; a second lens having negative optical power, the object-side surface of which is convex and the image-side surface of which is concave; a third lens element having positive optical power, whose object-side surface is convex and whose image-side surface is concave; a fourth lens element having positive refractive power, whose object-side surface is concave and whose image-side surface is convex; a fifth lens element having positive refractive power, whose object-side surface and image-side surface are convex; a sixth lens element having negative optical power and a concave image-side surface; a seventh lens element having positive refractive power and a convex image-side surface; An eighth lens element having positive refractive power, whose object-side surface is convex near the optical axis and whose image-side surface is concave; The ninth lens element has positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis; The real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy the following conditions: 3.7 <IH / f<3.9。 2. The optical lens according to claim 1, wherein: The total optical length TTL of the optical lens and the aperture value Fno of the optical lens meet the following requirements: 7mm <TTL / Fno<9.1mm。 3. The optical lens according to claim 1, wherein: The maximum field of view FOV of the optical lens and the chief ray incidence angle CRA at the maximum image height of the optical lens meet the following requirements: 3.8 <FOV / CRA<5.6。 4. The optical lens according to claim 1, wherein: The total optical length TTL of the optical lens and the sum of the center thicknesses of the first lens to the ninth lens along the optical axis ΣCT satisfy: 1.4 <TTL / ∑CT<1.8。 5. The optical lens according to claim 1, wherein: The object side light semi-aperture CSD31 of the third lens and the object side light semi-aperture sag SAG31 of the third lens meet the following conditions: 2.3 <CSD31 / SAG31<2.9。 6. The optical lens according to claim 1, wherein: The focal length f1 of the first lens, the curvature radius R1 of the object side surface of the first lens, and the curvature radius R2 of the image side surface of the first lens satisfy: -0.45 <f1 / (R1+R2)<-0.25。 7. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 3.1 <f7 / f<8.7。 8. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 20 <f8 / f<50。 9. The optical lens according to claim 1, wherein: The focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -0.97 <f5 / f6<-0.94。 10. The optical lens according to claim 1, wherein: The focal length f3 of the third lens, the focal length f4 of the fourth lens, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 8<(f3+f4+f5) / f<13.

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