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 fourth lens has negative focal power, and the object side surface of the fourth lens is a concave 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, and the image side surface of the sixth lens is a concave surface; the seventh lens has positive focal power; the eighth lens has negative 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 negative optical power and a concave object-side surface; 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, whose object-side surface and image-side surface are convex; An eighth lens element having negative optical power, whose image-side surface is concave near the optical axis; 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 total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy the following conditions: 4.4 <TTL / f<6.6。

[0005] Further preferably, 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 relationship: 2.2 <IH / f<3.1。

[0006] Further preferably, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens meet the following requirements: 6.4 mm <TTL / Fno<8.2mm。

[0007] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.8 <f1 / f<-2.8。

[0008] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -23 <f2 / f<-8。

[0009] Further preferably, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.8 <f6 / f<-1.5。

[0010] Further preferably, the focal length f9 of the ninth lens and the effective focal length f of the optical lens satisfy: 4.9 <f9 / f<7.4。

[0011] Further preferably, the object side semi-aperture R5 of the third lens and the effective focal length f of the optical lens satisfy the following relationship: 0.6 <R5 / f<1.3。

[0012] Further preferably, the object side light semi-aperture CSD11 of the first lens and the image side light semi-aperture CSD92 of the ninth lens meet the following conditions: 3.1 <CSD11 / CSD92<3.6。

[0013] Further preferably, the object-side clear light half-aperture sag height SAG91 of the ninth lens, the image-side clear light half-aperture sag height SAG92 of the ninth lens, and the center thickness CT9 of the ninth lens satisfy the following relationship: -3.5<(SAG91+SAG92) / CT9<-1.6.

[0014] Compared with the existing technology, the optical lens provided by the present invention uses nine lenses with specific optical focal lengths. Through specific surface shape matching and reasonable optical focal length 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 following description of the embodiments with reference to the accompanying 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 3Graph 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 in an embodiment of the present invention comprises nine lenses in total. The optical lens comprises, in order from the object side to the imaging surface along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens.

[0036] In some embodiments, the first lens may have a negative optical power, with its object side being convex and its image side being concave. The second lens may have a negative optical power, with its object side being convex and its image side being concave. The third lens may have a positive optical power, with its object side being convex and its image side being concave. The fourth lens may have a negative optical power, with its object side being concave and its image side being either concave or convex. The fifth lens may have a positive optical power, with its object side being convex and its image side being convex. The sixth lens may have a negative optical power, with its object side being either concave or convex and its image side being concave. The seventh lens may have a positive optical power, with its object side being convex and its image side being convex. The eighth lens may have a negative optical power, with its object side being either concave or convex and its image side being concave near the optical axis. The ninth lens may have a positive optical power, with its object side being convex near the optical axis and its image side being 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 formation. When the aperture is located between the fourth lens and the fifth lens, it is convenient for the correction of 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 and prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0039] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.4 < TTL / f < 6.6. Satisfying the above conditional formula can reasonably configure the ratio of the total optical length to the effective focal length of the optical lens, which is beneficial to the miniaturization design of the optical lens. At the same time, it is also beneficial for the optical lens to have a reasonable field angle range while achieving a certain focal length characteristic, so as to meet the wide-angle design of the optical lens and enable the optical lens to obtain sufficient object-side space information.

[0040] 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: 2.2 < IH / f < 3.1. 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 ensuring the matching of a chip with a large image surface, that is, enabling the optical lens to have the characteristics of a large field angle and a large image surface.

[0041] In some embodiments, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens satisfy: 6.4mm < TTL / Fno < 8.2mm. By satisfying the above conditional formula, by controlling the relationship between the total length and the aperture value 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-clarity shooting.

[0042] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.8 < f1 / f < -2.8. By satisfying the above conditional formula, setting the first lens of the optical lens as a negative-power lens can capture the light rays entering the optical lens at a large angle, expand the field angle range of the optical lens, and is also beneficial to reducing the sensitivity of the optical lens and realizing the miniaturization design of the optical lens.

[0043] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -23 < f2 / f < -8. By satisfying the above conditional formula, reasonably controlling the focal length value of the second lens makes the light divergence increase slowly, which is beneficial to realizing a large aperture and a large target surface. At the same time, it is beneficial to the gentle trend of the light rays, reducing the generation of aberration, and is beneficial to realizing high image quality and ensuring tolerance performance.

[0044] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.8 < f6 / f < -1.5. By satisfying the above conditional formula, reasonably controlling the focal length value of the sixth lens makes the light rays in the large field of view rise slowly, changing the parallel light trend of the light beam to a divergent trend, which is beneficial to controlling the back focal length of the lens and is beneficial to realizing a large target surface and reducing the principal ray incident angle.

[0045] In some embodiments, the focal length f9 of the ninth lens and the effective focal length f of the optical lens satisfy: 4.9 < f9 / f < 7.4. By satisfying the above conditional formula, reasonably controlling the focal length value of the ninth lens, the light beam changes from a divergent trend to a focused trend, reducing the optical path and the aperture of the subsequent lenses, which is beneficial to realizing miniaturization and real-time athermalization functions.

[0046] In some embodiments, the half-aperture R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 0.6 < R5 / f < 1.3. By satisfying the above conditional formula, such a setting makes the shape of the object side surface of the third lens convex, causing the light rays passing through the second lens to contract into the subsequent lenses, which can reduce the size of the subsequent lenses, contribute to the miniaturization of the optical lens, and the third lens can effectively reduce the generation of spherical aberration and astigmatism to improve the imaging quality of the optical lens.

[0047] In some embodiments, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the clear aperture semi-diameter CSD92 of the image side surface of the ninth lens satisfy: 3.1 < CSD11 / CSD92 < 3.6. Meeting the above conditional formula enables the optical lens to have a relatively large aperture, better achieve large-angle light collection, realize ultra-wide-angle imaging of the optical lens, and at the same time increase the imaging area of the optical lens to achieve large-format imaging of the optical lens.

[0048] In some embodiments, the sagittal height SAG91 of the clear aperture semi-diameter of the object side surface of the ninth lens, the sagittal height SAG92 of the clear aperture semi-diameter of the image side surface of the ninth lens, and the central thickness CT9 of the ninth lens satisfy: -3.5 < (SAG91 + SAG92) / CT9 < -1.6. Meeting the above conditional formula is beneficial to controlling the refractive power and thickness of each part of the ninth lens in the direction perpendicular to the optical axis, avoiding the ninth lens being too thick or too thin, reducing the incident angle of light on the object side surface of the ninth lens, and reducing the tolerance sensitivity of the optical lens; at the same time, the ninth lens has multiple anti-curved points, which is beneficial to correcting the distortion and field curvature generated by the object side lens of the ninth lens, and evenly distributing the refractive power of multiple lenses near the imaging surface of the optical lens.

[0049] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.8 < f5 / f < 1.1. Meeting the above conditional formula is beneficial to controlling the angle of light incident on the imaging surface of the optical lens, 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 radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -1.1 < R10 / f < -0.7. Meeting the above conditional formula makes the image side surface of the fifth lens convex, which is beneficial to converging light, does not generate aberration, and also helps to miniaturize the optical lens.

[0051] In some embodiments, the effective focal length f of the optical lens, the radian value θ of the maximum field angle of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.6 < IH / (f×θ) < 1.2. Meeting the above conditional formula can control the peripheral distortion of the optical lens, is beneficial to realizing the relatively large field angle and large image surface characteristics of the optical lens, and at the same time can effectively increase the proportion of the peripheral field of the optical lens in the entire image surface, enabling the optical lens to meet the high-pixel characteristics and improving the imaging quality of the optical lens.

[0052] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: -16 < (R7 + R8) / (R7 - R8) < -0.7. By satisfying the above conditional formula, the surface profiles of the object side surface and the image side surface of the fourth lens are controlled, effectively correcting the spherical aberration of the optical lens, while reducing the influence of astigmatism on the imaging of the optical lens. In addition, the effective aperture in the optical path can be increased, enabling the optical lens to have a large field angle and be ultra-thin.

[0053] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the sagittal height SAG11 of the clear aperture radius of the object side surface of the first lens satisfy: 3.8 < R1 / SAG11 < 5.2. By satisfying the above conditional formula, by controlling the ratio relationship between the radius of curvature of the object side surface of the first lens and the sagittal height of the object side surface, a negative refractive power is provided for the optical lens, thereby capturing the light rays entering the optical lens at large angles and expanding the field angle range of the optical lens.

[0054] In some embodiments, the optical lens satisfies the following conditional formula: 2 mm < f < 2.8 mm; 150° ≤ FOV < 210°; 1 mm < EPD < 1.5 mm; 12 mm < TTL < 13.2 mm; 1.5 < Fno < 1.9; 5.9 mm < IH < 6.2 mm; where f represents the effective focal length of the optical lens, FOV represents the maximum field 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 aperture value of the optical lens, and IH represents the image height corresponding to the maximum field angle of the optical lens. By satisfying the above conditional formula, the optical lens has at least one or more advantages such as short focal length, large field angle, large entrance pupil diameter, short total length, large aperture, large target surface, low distortion, and low sensitivity.

[0055] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The first lens and the fourth lens in the optical lens provided by the present invention can adopt glass materials, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens can adopt plastic materials. 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.

[0056] In some embodiments, the first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth lenses may be spherical or aspherical lenses. Compared to spherical lenses, aspherical structures can effectively reduce the aberrations of the optical system, thereby reducing the number and size of lenses and achieving better miniaturization. More specifically, the first and fourth lenses of the present invention are spherical lenses; the second, third, fifth, sixth, seventh, eighth, and ninth lenses are aspherical lenses.

[0057] In various embodiments of the present invention, when the lens is an aspheric lens, the shapes of the aspheric 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.

[0058] 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.

[0059] 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.

[0060] 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 negative refractive power, its object-side surface S7 is concave, and its image-side surface S8 is concave; 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 negative refractive power, its object-side surface S15 is convex near the optical axis, and its image-side surface S16 is concave near the optical axis; 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.

[0061] 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.

[0062] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0063] Table 1-1 The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0064] 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.

[0065] 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 -10% to 20%, indicating that the optical lens 100 is able to correct distortion well.

[0066] Figure 3A field curvature graph of the optical lens 100 in this embodiment is shown, showing 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 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 a range of -0.1mm to 0.05mm, indicating that the optical lens 100 can effectively correct field curvature.

[0067] 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 both the longest and shortest wavelengths is controlled within 0 to 5 μm, demonstrating that the optical lens 100 is capable of effectively correcting vertical chromatic aberration.

[0068] Example 2 See also Figure 5 , shown is a schematic structural diagram of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S8 of the fourth lens L4 is convex; the object-side surface S11 of the sixth lens L6 is concave; the object-side surface S15 of the eighth lens L8 is concave; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

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

[0070] Table 2-1 The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0071] 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.

[0072] from Figure 6 It can be seen that the distortion value is controlled within -40% to 0, indicating that the optical lens 200 can correct the distortion well.

[0073] 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.

[0074] 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.

[0075] Example 3 See also Figure 9 , shown is a schematic structural diagram of an optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S8 of the fourth lens L4 is convex; the object-side surface S11 of the sixth lens L6 is concave; the object-side surface S15 of the eighth lens L8 is concave; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0076] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0077] Table 3-1 The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0078] 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.

[0079] from Figure 10 It can be seen that the distortion value is controlled within -30% to 0, indicating that the optical lens 300 can correct the distortion well.

[0080] 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 -0.15mm~0.1mm, indicating that the optical lens 300 can correct the field curvature well.

[0081] 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 -3μm~5μm, indicating that the optical lens 300 can well correct the vertical axis chromatic aberration.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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 negative optical power and a concave object-side surface; 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, whose object-side surface and image-side surface are convex; An eighth lens element having negative optical power, whose image-side surface is concave near the optical axis; 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 total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy the following conditions: 4.4 <TTL / f<6.6。 2. The optical lens according to claim 1, wherein: 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: 2.2 <IH / f<3.1。 3. 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: 6.4mm <TTL / Fno<8.2mm。 4. The optical lens according to claim 1, wherein: The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.8 <f1 / f<-2.8。 5. The optical lens according to claim 1, wherein: The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -23 <f2 / f<-8。 6. The optical lens according to claim 1, wherein: The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.8 <f6 / f<-1.5。 7. The optical lens according to claim 1, wherein: The focal length f9 of the ninth lens and the effective focal length f of the optical lens satisfy: 4.9 <f9 / f<7.4。 8. The optical lens according to claim 1, wherein: The object side semi-aperture R5 of the third lens and the effective focal length f of the optical lens satisfy: 0.6 <R5 / f<1.3。 9. The optical lens according to claim 1, wherein: The object side light semi-aperture CSD11 of the first lens and the image side light semi-aperture CSD92 of the ninth lens meet the following conditions: 3.1 <CSD11 / CSD92<3.6。 10. The optical lens according to claim 1, wherein: The object side light semi-aperture sag height SAG91 of the ninth lens, the image side light semi-aperture sag height SAG92 of the ninth lens, and the center thickness CT9 of the ninth lens satisfy the following: -3.5<(SAG91+SAG92) / CT9<-1.6.

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