Optical lens

Abstract

This invention provides an optical lens comprising nine lenses, arranged sequentially along the optical axis from the object side to the image plane: a first lens with negative optical power, its object side being convex and its image side being concave; a second lens with negative optical power, its object side being convex and its image side being concave; a third lens with positive optical power, its object side being convex and its image side being concave; a fourth lens with positive optical power, its image side being convex; a fifth lens with positive optical power, its object side being convex; a sixth lens with negative optical power, its image side being concave; a seventh lens with positive optical power; an eighth lens with negative optical power; and a ninth lens with positive optical power. The optical lens provided by this invention, through specific surface shape combinations and a reasonable distribution of optical power, enables the lens to possess one or more advantages such as short focal length, miniaturization, large field of view, large aperture, large image surface, low distortion, and low sensitivity.

Description

Technical Field

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

[0002] With the rapid development of fields such as drones, security, automobiles, meteorology, medical, VR, and AR, increasingly higher demands are being placed on the field of view of the lenses they are equipped with. Wide-angle lenses, by introducing barrel distortion, compress light at the edges 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, common ultra-wide-angle lenses have relatively small apertures, resulting in insufficient light intake and unclear images in low-light environments. In addition, there are problems such as difficulty in aberration correction, large distortion, and defocusing under high and low temperature conditions. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0004] This invention provides an optical lens comprising nine lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0005] The first lens with negative optical power has a convex object side and a concave image side.

[0006] A second lens with negative optical power has a convex object side and a concave image side.

[0007] A third lens with positive optical power has a convex object-side surface and a concave image-side surface.

[0008] The fourth lens has positive optical power and its image-side surface is convex.

[0009] The fifth lens with positive optical power has a convex object-side surface;

[0010] The sixth lens has negative optical power and its image-side surface is concave.

[0011] The seventh lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0012] The eighth lens, which has negative optical power, has an image-side surface that is concave near the optical axis.

[0013] The ninth lens with positive optical power has an object-side surface that is convex near the optical axis and an image-side surface that is concave near the optical axis.

[0014] Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7.4 <TTL / f<8.1。

[0015] Further preferably, the effective focal length f of the optical lens and the aperture value Fno of the optical lens satisfy: 0.8 mm < f / Fno < 1.2 mm.

[0016] Further preferably, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 8.3 < TTL / IH < 9.1.

[0017] Further preferably, the clear aperture semi-diameter CSD91 of the object side surface of the ninth lens and the sagitta SAG91 of the clear aperture semi-diameter of the object side surface of the ninth lens satisfy: -3.3 < CSD91 / SAG91 < -2.5.

[0018] Further preferably, the overall 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 respectively satisfy: 1.4 < TTL / ∑CT < 1.8.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3.5 < f1 / f < -2.7; the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -6.7 < f2 / f < -3.4.

[0020] Further preferably, 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: 0.9 < IH / (f×θ) < 1.5.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.1 < f4 / f < 2.9.

[0022] Further preferably, the effective focal length f of the optical lens and the focal length f9 of the ninth lens satisfy: 2.9 < f9 / f < 18.

[0023] Further preferably, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the clear aperture semi-diameter CSD81 of the object side surface of the eighth lens satisfy: 3.5 < CSD11 / CSD81 < 4.

[0024] Compared with the prior art, the optical lens provided by the present invention adopts nine lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberrations, improve the imaging quality of the optical lens, and endow the lens with one or more advantages of short focal length, miniaturization, large field angle, large aperture, large target surface, low distortion, and low sensitivity. Description of the Drawings

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

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

[0027] Figure 2 This is an F-Theta distortion curve of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 3 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 4 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 5 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0031] Figure 6 This is the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

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

[0033] Figure 8 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 9 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 10 This is the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

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

[0037] Figure 12 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0038] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0039] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0041] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0042] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0043] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0044] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0045] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments 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.

[0046] The optical lens provided by the embodiment of the present invention has a total of nine lenses. The optical lens sequentially includes: 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 along the optical axis from the object side to the imaging surface.

[0047] In some embodiments, the first lens may have a negative optical power, its object side is convex, and its image side is concave. The second lens may have a negative optical power, its object side is convex, and its image side is concave. The third lens may have a positive optical power, its object side is convex, and its image side is concave. The fourth lens may have a positive optical power, its object side may be concave or convex, and its image side is convex. The fifth lens may have a positive optical power, its object side is convex, and its image side may be concave or convex. The sixth lens may have a negative optical power, its object side may be concave or convex, and its image side is concave. The seventh lens may have a positive optical power, its object side is convex, and its image side is convex. The eighth lens may have a negative optical power, its object side may be concave or convex, and its image side is concave near the optical axis. The ninth lens may have a positive optical power, its object side is convex near the optical axis, and its image side is concave near the optical axis.

[0048] 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.

[0049] 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.

[0050] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7.4 < TTL / f < 8.1. 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 realizing the miniaturized 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 realizing certain focal length characteristics, so as to meet the wide-angle design of the optical lens and enable the optical lens to obtain sufficient object-side spatial information.

[0051] In some embodiments, the effective focal length f of the optical lens and the aperture value Fno of the optical lens satisfy: 0.8 mm < f / Fno < 1.2 mm. Satisfying the above conditional formula is beneficial for the optical lens to obtain the characteristic of a large aperture, enabling the optical lens to have sufficient light intake, which is conducive to making the captured image clearer; at the same time, a short focal length combined with a large aperture enables the optical lens to have a large wide-angle field of view to capture more scene information, and at the same time solves the problem of low-light shooting through the large aperture, and enhances the sense of picture layering with flexible depth-of-field control.

[0052] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 8.3 < TTL / IH < 9.1. Satisfying the above conditional formula and reasonably configuring the overall optical length of the optical lens and the true image height corresponding to the maximum field angle can effectively shorten the overall optical length of the optical lens while ensuring that the optical lens has high pixels, enabling the optical lens to meet the requirements of miniaturization while having high imaging quality.

[0053] In some embodiments, the clear aperture semi-diameter CSD91 of the object side of the ninth lens and the sagittal height SAG91 of the clear aperture semi-diameter of the object side of the ninth lens satisfy: -3.3 < CSD91 / SAG91 < -2.5. Satisfying the above conditional formula can prevent the object side of the ninth lens from being overly curved, reducing the processing difficulty and coating difficulty of the ninth lens, and at the same time is also conducive to the incidence of large-angle light rays onto the imaging surface, thereby improving the imaging quality of the optical lens; and it can also avoid the object side of the ninth lens from being overly flat, reducing the risk of ghosting.

[0054] In some embodiments, the overall 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 respectively satisfy: 1.4 < TTL / ∑CT < 1.8. Satisfying the above conditional formula and reasonably configuring the overall optical length of the optical lens and the sum of the thicknesses of each lens helps to achieve the characteristic of high pixels and improve the imaging quality of the optical lens; at the same time, it can effectively shorten the overall optical length of the optical lens, meeting the design requirements of miniaturization and lightweight.

[0055] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3.5 < f1 / f < -2.7; the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -6.7 < f2 / f < -3.4. Satisfying the above conditional expressions, setting the first lens of the optical lens as a lens with negative optical power can capture the light rays entering the optical lens at a large angle, expanding the field angle range of the optical lens; at the same time, it is also beneficial to reduce the sensitivity of the optical lens and achieve the miniaturized design of the optical lens. And further controlling the focal length value of the second lens makes the light rays entering the first lens and the second lens diverge in sequence, causing the large-field light rays to rise slowly, which is beneficial to achieving a large aperture and a large target surface, and at the same time is beneficial to the gentle trend of the light rays, reducing the generation of aberration, and is beneficial to achieving high image quality and ensuring tolerance performance.

[0056] 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: 0.9 < IH / (f×θ) < 1.5. Satisfying the above conditional expressions can control the peripheral distortion of the optical lens, which is beneficial to achieving the characteristics of a larger field angle and a large image surface of the optical lens, and at the same time can effectively control the proportion of the peripheral field of the optical lens in the entire image surface, making the optical lens meet the high-pixel characteristics and improving the imaging quality of the optical lens.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.1 < f4 / f < 2.9. Satisfying the above conditional expressions, by setting the fourth lens to have a large positive refractive power, the aberration of the peripheral field can be effectively improved, and the overall imaging quality of the optical lens can be enhanced.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f9 of the ninth lens satisfy: 2.9 < f9 / f < 18. Satisfying the above conditional expressions, reasonably controlling the focal length value of the ninth lens, the light beam changes from a divergent trend to a convergent trend, reducing the optical path and the aperture of the subsequent lens, which is beneficial to achieving a miniaturized volume and a real-time athermalization function.

[0059] In some embodiments, the clear aperture radius CSD11 of the object side surface of the first lens and the clear aperture radius CSD81 of the object side surface of the eighth lens satisfy: 3.5 < CSD11 / CSD81 < 4. Satisfying the above conditional expressions enables the optical lens to have a large aperture, which can better achieve the collection of large-angle light rays, realize the ultra-wide-angle imaging of the optical lens, and at the same time can increase the imaging area of the optical lens, realizing the large-target-surface imaging of the optical lens.

[0060] 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: 3.3 < IH / f < 3.7. 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 ensuring compatibility with a chip having a large image plane, that is, enabling the optical lens to have the characteristics of both a large field angle and a large image plane.

[0061] In some embodiments, the maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 80° < FOV / Fno < 150°. By satisfying the above conditional formula, it is ensured that the optical lens meets certain requirements of a large field angle and a large aperture, reducing the influence of off-axis aberrations on the system, and at the same time ensuring an increase in the brightness of the imaging plane, thereby improving the imaging quality.

[0062] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.4 < f1 / f2 < 0.8. By satisfying the above conditional formula, both the first lens and the second lens are set to negative optical powers, which is beneficial for increasing the back focal length of the system, avoiding interference during assembly with the chip, and at the same time, in the ultra-wide-angle state, it can converge the incident light angle so that it enters the aperture at a small angle, which is beneficial for balancing the off-axis aberrations of the system.

[0063] In some embodiments, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.5 < (R1 - R2) / (R1 + R2) < 0.7. By satisfying the above conditional formula, by reasonably defining the shapes of the object side surface and the image side surface of the first lens, the distortion generated by the first lens can be reduced, the difficulty of distortion correction of the subsequent lenses can be reduced, and it is helpful to improve the imaging quality.

[0064] 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 formula, the surface shapes of the object side surface and the image side surface of the first lens can be constrained, which is beneficial for reducing the bending degree of light at the image side surface of the first lens, reducing the astigmatism of the optical lens, so as to balance the astigmatism problem brought by the large field angle of the optical lens, so that when the optical lens has a large field of view, the astigmatism is not too large, and thus ensuring that the optical lens has excellent imaging quality.

[0065] 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 semi-diameter at the object side surface of the first lens satisfy: 5.7 < R1 / SAG11 < 11. By satisfying the above conditional formula, the ratio relationship between the radius of curvature of the object side surface of the first lens and the sagittal height at the maximum effective aperture can be controlled, providing a negative refractive power for the optical lens, thereby capturing the light rays that enter the optical lens at large angles and expanding the field angle range of the optical lens.

[0066] In some embodiments, the optical lens satisfies the following conditional formula: 1.5 mm < f < 1.9 mm; 150° ≤ FOV < 220°; 0.8 mm < EPD < 1.1 mm; 11 mm < TTL < 14 mm; 1.4 < Fno < 1.9; 5.7 mm < IH < 6.3 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.

[0067] 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, 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 use 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 use 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.

[0068] 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 use 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 use spherical lenses; the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens use aspherical lenses.

[0069] In each embodiment of the present invention, when the lens uses an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0070]

[0071] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, H, I, and J are the fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, eighteenth, and twentieth order surface coefficients, respectively.

[0072] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0073] Example 1

[0074] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane S21, the following components in sequence: 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.

[0075] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0076] The second lens L2 has negative optical power, its object side S3 is convex, and its image side S4 is concave.

[0077] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is concave.

[0078] The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side S8 is convex.

[0079] The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side S10 is convex.

[0080] The sixth lens L6 has negative optical power, its object side S11 is convex near the optical axis, and its image side S12 is concave.

[0081] The seventh lens L7 has positive optical power, its object side S13 is convex, and its image side S14 is convex.

[0082] The eighth lens L8 has negative optical power, its object side S15 is convex near the optical axis, and its image side S16 is concave near the optical axis.

[0083] The ninth lens L9 has positive optical power, its object side S17 is convex near the optical axis, and its image side S18 is concave near the optical axis.

[0084] The object-side surface S19 and the image-side surface S20 of filter G1 are both planar.

[0085] The imaging plane S21 is a plane.

[0086] 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 all plastic aspherical lenses.

[0087] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0088] Table 1-1

[0089]

[0090]

[0091] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0092] Table 1-2

[0093]

[0094]

[0095] In this embodiment, the F-Theta distortion curve, field curvature curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 As shown.

[0096] Figure 2 The F-Theta distortion curve of the optical lens 100 in this embodiment is shown, which represents the distortion at different field-of-view angles on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the distortion value is controlled within -10% to 20%, indicating that the optical lens 100 can correct distortion well.

[0097] Figure 3The field curvature curve of the optical lens 100 in this embodiment is shown, which represents 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 of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.05 mm, indicating that the optical lens 100 can correct the field curvature well.

[0098] Figure 4 The diagram shows the transverse chromatic aberration curve of the optical lens 100 in this embodiment. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3 μm to 4 μm, indicating that the optical lens 100 can effectively correct transverse chromatic aberration.

[0099] Example 2

[0100] Please see Figure 5 The figure shown is a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S10 of the fifth lens L5 is concave; the object side surface S15 of the eighth lens L8 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0101] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0102] Table 2-1

[0103]

[0104]

[0105] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0106] Table 2-2

[0107]

[0108]

[0109] In this embodiment, the F-Theta distortion curve, field curvature curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0110] from Figure 6As can be seen, the distortion value is controlled within -5% to 15%, indicating that the optical lens 200 can correct distortion well.

[0111] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.05mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0112] from Figure 8 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 3μm, indicating that the optical lens 200 can effectively correct transverse chromatic aberration.

[0113] Example 3

[0114] Please see Figure 9 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S7 of the fourth lens L4 is concave; the object side surface S11 of the sixth lens L6 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0115] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0116] Table 3-1

[0117]

[0118]

[0119] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0120] Table 3-2

[0121]

[0122]

[0123] In this embodiment, the F-Theta distortion curve, field curvature curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown.

[0124] from Figure 10 As can be seen, the distortion value is controlled within 0-50%, indicating that the optical lens 300 can correct distortion well.

[0125] from Figure 11As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.05mm, indicating that the optical lens 300 can effectively correct the field curvature.

[0126] from Figure 12 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -2μm to 3μm, indicating that the optical lens 300 can effectively correct transverse chromatic aberration.

[0127] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0128] Table 4

[0129]

[0130]

[0131] In summary, the optical lens provided by the present invention uses nine lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens. This allows the lens to have one or more advantages such as short focal length, miniaturization, large field of view, large aperture, large target surface, low distortion, and low sensitivity.

[0132] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0133] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens, comprising nine pieces of lenses, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is convex and whose image side is concave; A second lens with a negative optical power, whose object side is convex and whose image side is concave; A third lens with a positive optical power, whose object side is convex and whose image side is concave; A fourth lens with a positive optical power, whose image side is convex; A fifth lens with a positive optical power, whose object side is convex; A sixth lens with a negative optical power, whose image side is concave; A seventh lens with a positive optical power, whose object side is convex and whose image side is convex; An eighth lens with a negative optical power, whose image side is concave near the optical axis; A ninth lens with a positive optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7.4 < TTL / f < 8.1; The clear aperture semi-diameter CSD91 of the object side of the ninth lens and the sagittal height SAG91 of the clear aperture of the object side of the ninth lens satisfy: -3.3 < CSD91 / SAG91 < -2.5; The clear aperture semi-diameter CSD11 of the object side of the first lens and the clear aperture semi-diameter CSD81 of the object side of the eighth lens satisfy: 3.5 < CSD11 / CSD81 < 4.

2. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the f-number Fno of the optical lens satisfy: 0.8mm < f / Fno < 1.2mm.

3. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 8.3 < TTL / IH < 9.

1.

4. The optical lens according to claim 1, characterized in that, 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: 3.3 < IH / f < 3.

7.

5. The optical lens according to claim 1, characterized in that, 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 respectively satisfy: 1.4 < TTL / ∑CT < 1.

8.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3.5 < f1 / f < -2.7; The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -6.7 < f2 / f < -3.

4.

7. The optical lens according to claim 1, characterized in that, 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: 0.9 < IH / (f×θ) < 1.

5.

8. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.1 < f4 / f < 2.

9.

9. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f9 of the ninth lens satisfy: 2.9 < f9 / f < 18.

10. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.4 < f1 / f2 < 0.8.

Images