Optical lens

Abstract

The application provides an optical lens, which comprises eight lenses in sequence along an optical axis from an object side to an imaging surface, and the eight lenses comprise: a first lens with negative optical power, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative optical power, wherein the image side surface of the second lens is a concave surface; a third lens with positive optical power, wherein 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; a fourth lens with positive optical power, wherein the image side surface of the fourth lens is a convex surface; a fifth lens with positive optical power, wherein 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; a sixth lens with negative optical power, wherein the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a concave surface; a seventh lens with positive optical power, wherein the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a convex surface; and an eighth lens with negative optical power. The optical lens provided by the application has one or more advantages of super wide angle, high pixel, large aperture, small distortion, high imaging quality and the like through specific surface shape matching and reasonable optical power distribution.

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 an ultra-wide-angle lens with a field of view exceeding 220°. 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. Additionally, aberration correction is difficult, and there are issues such as excessively large lens heads. 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 eight 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 concave image-side surface;

[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 and a convex image-side surface.

[0010] The sixth lens has negative optical power, with both its object-side and image-side surfaces being 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 with negative 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.

[0013] Wherein, the true image height IH corresponding to the maximum field of view of the optical lens and the half-aperture CSD11 of the object side surface of the first lens satisfy: 1.1 <IH / CSD11≤1.2。

[0014] Further preferably, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 125° < FOV / Fno < 145°.

[0015] Further preferably, the true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 5.5 < IH / EPD < 6.

[0016] Further preferably, the aperture value Fno of the optical lens and the effective focal length f of the optical lens satisfy: 0,9 mm < f / Fno < 1.1 mm.

[0017] [[ID=⑨]]Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.9 < f1 / f < -3.7; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.9 < f2 / f < -2.3.

[0018] Further preferably, the combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: -1.8 < f123 / f < -1.3. colspan="2">

[0019] Further preferably, the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 1.2 < f45678 / f < 1.5.

[0020] 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: -0.6 < f1 / (R1 + R2) < -0.5.

[0021] Further preferably, the clear aperture semi-diameter CSD1l 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: 2.3 < CSD11 / CSD81 < 2.7. <000004⑤>

[0022] Further preferably, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the sagitta SAGX11 of the clear aperture semi-diameter of the object side surface of the first lens satisfy: 2.4 < CSD11 / SAGX11 < 3.2.

[0023] Compared with the prior art, the optical lens provided by the present invention adopts eight lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and make the lens have one or more advantages such as ultra-wide angle, high pixel, large aperture, small distortion, and high imaging quality. It should be noted that in the original text, "⑨" in [[ID=⑨]] should be "9" in English, which is a possible error in the original text. I have translated it as "⑨" according to the original text. If this is a specific code or needs to be corrected, please adjust it according to the actual situation. Attached Figure Description

[0024] 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:

[0025] Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0026] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 This is an F-Theta distortion curve of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 6 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0031] Figure 7 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 8 This is the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 9 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 10 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 11 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

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

[0037] Figure 13 This is the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 14 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0039] Figure 15This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0040] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] The optical lens provided in this embodiment of the invention comprises eight lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane as follows: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens.

[0049] In some embodiments, the first lens may have negative optical power, with a convex object-side surface and a concave image-side surface. The second lens may have negative optical power, with either a concave or convex object-side surface and a concave image-side surface. The third lens may have positive optical power, with a convex object-side surface and a concave image-side surface. The fourth lens may have positive optical power, with either a concave or convex object-side surface and a convex image-side surface. The fifth lens may have positive optical power, with both a convex object-side and image-side surface. The sixth lens may have negative optical power, with both a concave object-side and image-side surface. The seventh lens may have positive optical power, with both a convex object-side and image-side surface. The eighth lens may have negative optical power, with a convex object-side surface near the optical axis and a concave image-side surface near the optical axis.

[0050] In some embodiments, the optical lens may also include an aperture stop, which may be located between the fourth and fifth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens to change the brightness of the image. When the aperture stop is located between the fourth and fifth lenses, it facilitates the correction of aperture aberrations.

[0051] In some embodiments, the optical lens may further include a filter disposed between the eighth lens and the imaging surface. The filter is used to filter out interfering light and prevent it from reaching the imaging surface of the optical lens and affecting normal imaging.

[0052] In some embodiments, the sixth and seventh lenses can be cemented together to form a cemented lens, which can effectively correct chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberrations of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0053] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the clear aperture semi-diameter CSD11 of the object side surface of the first lens satisfy: 1.1 < IH / CSD11 ≤ 1.2. Meeting the above conditional formula ensures that the clear aperture of the first lens is maintained within a reasonable range, enabling the optical lens to meet the requirements of a small-aperture design, thereby enhancing the compactness of the optical lens; at the same time, it is also beneficial to improve the refraction ability of the first lens to light, thereby reducing distortion and aberration, and enabling the optical lens to match a chip with a large image surface, improving the imaging quality of the optical lens.

[0054] In some embodiments, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 125° < FOV / Fno < 145°. Meeting the above conditional formula ensures that the optical lens meets the requirements of an ultra-large field angle and a large aperture, reduces the influence of off-axis aberration on the system, enables the optical lens to have the characteristics of a large aperture, high relative illumination, and small distortion, thereby improving the imaging quality.

[0055] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 5.5 < IH / EPD < 6. Meeting the above conditional formula can enable an optical lens with a large image surface to have a relatively large entrance pupil diameter and a high light transmission amount, thereby enhancing the imaging effect when the optical lens operates in a dark environment, reducing the aberration of the edge field of view.

[0056] In some embodiments, the aperture value Fno of the optical lens and the effective focal length f of the optical lens satisfy: 0.9mm < f / Fno < 1.1mm. Meeting 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 input, 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, solves the problem of weak light shooting through the large aperture, and enhances the picture layering through flexible depth-of-field control.

[0057] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.9 < f1 / f < -3.7; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.9 < f2 / f < -2.3. Meeting the above conditional formula, setting both the first lens and the second lens of the optical lens as lenses with negative optical power can control the incident angle of light, expand the field angle range of the optical lens, and increase the back focal length of the optical lens at the same time, avoiding interference between the lens and the photosensitive chip; at the same time, the second lens having negative optical power is also beneficial for aberration correction, which can further improve the imaging quality of the optical lens.

[0058] In some embodiments, the combined focal length f123 of the first lens, the second lens, and the third lens and the effective focal length f of the optical lens satisfy: -1.8 < f123 / f < -1.3. Meeting the above conditions, the front lens group composed of the first lens, the second lens, and the third lens provides a negative optical power for the optical lens, which is conducive to large-angle light beams passing through and entering the aperture of the optical lens, so as to achieve the ultra-wide angle of the optical lens and improve the image plane brightness of the large-angle field of view of the optical lens.

[0059] In some embodiments, the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens and the effective focal length f of the optical lens satisfy: 1.2 < f45678 / f < 1.5. Meeting the above conditional formula is conducive to correcting the chromatic aberration and field curvature of the optical lens, slowing down the light deflection angle, reducing sensitivity, reducing the lens forming difficulty, and achieving the balance of the overall spherical aberration to obtain good imaging quality for the on-axis field of view.

[0060] 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: -0.6 < f1 / (R1 + R2) < -0.5. Meeting the above conditional formula can constrain the surface shapes of the object side and the image side of the first lens, which is conducive to reducing the bending degree of light at the image side surface of the first lens and reducing the astigmatism of the optical lens to balance the astigmatism problem brought by the large field angle of the optical lens, so that the astigmatism of the optical lens will not be too large while having a large field of view, thereby ensuring that the optical lens has excellent imaging quality.

[0061] In some embodiments, 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: 2.3 < CSD11 / CSD81 < 2.7. Meeting the above conditional formula, by controlling the ratio of the clear aperture semi-diameter at the object side end of the first lens and the clear aperture semi-diameter at the object side end of the eighth lens, the optical lens can have a smaller aperture size, which is convenient for being mounted on an unmanned aerial vehicle device; at the same time, it ensures that the optical lens can collect large-angle light, achieve large-field-angle imaging of the optical lens, increase the imaging area of the optical lens, and improve the imaging quality.

[0062] In some embodiments, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the sagitta SAGX11 of the clear aperture semi-diameter of the object side surface of the first lens satisfy: 2.4 < CSD11 / SAGX11 < 3.2. Meeting the above conditional formula restricts the object side surface of the first lens, enabling the optical lens to meet the small-aperture design requirements, which is conducive to compressing the central field of view of the optical lens and making the imaging quality of the edge field of view better.

[0063] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 5 < f3 / f < 15. By satisfying the above conditional formula, by providing the third lens with a positive optical power and defining the ratio of the focal length of the third lens to the effective focal length of the optical lens, it is beneficial to adjust the light path from the first lens and the second lens, enabling the optical lens to have characteristics such as a certain large field of view angle, low sensitivity, and miniaturization.

[0064] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -4 < f8 / f < -1.9. By satisfying the above conditions, the marginal field light can be converged, which helps to optimize the imaging performance under low light conditions and provides better image brightness and contrast.

[0065] In some embodiments, the clear aperture semi-diameter CSD81 of the object side surface of the eighth lens and the sagittal height SAGX81 of the clear aperture of the object side surface of the eighth lens satisfy: -3.5 < CSD81 / SAGX81 < -3.3. By satisfying the above conditions, controlling the surface shape of the object side end of the eighth lens helps the light to transition smoothly, and at the same time can improve the ghost images of the optical lens, reduce the sensitivity of the optical lens, and improve the imaging quality.

[0066] In some embodiments, the clear aperture semi-diameter CSD82 of the image side surface of the eighth lens and the sagittal height SAGX82 of the clear aperture of the image side surface of the eighth lens satisfy: 7 < CSD82 / SAGX82 < 17. By satisfying the above conditional formula, it is possible to prevent the image side surface of the eighth lens from being overly curved, reduce the processing difficulty and coating difficulty of the eighth lens, and at the same time it is also beneficial for large-angle light to enter the imaging surface, thereby improving the imaging quality of the optical lens.

[0067] In some embodiments, the sagittal height SAGX11 of the clear aperture of the object side surface of the first lens and the central thickness CT1 of the first lens satisfy: 2.2 < SAGX11 / CT1 < 2.7. By satisfying the above conditional formula, controlling the ratio of the sagittal height of the object side surface 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 surface tend to be curved; at the same time, a larger sagittal height is beneficial for the first lens to collect large field of view light, achieve high angular resolution at the center of the optical lens, and further improve the imaging quality of the central region.

[0068] In some embodiments, the optical lens satisfies the following conditional formula: 1.55 mm < f < 1.65 mm; 200° ≤ FOV < 220°; 0.95 mm < EPDI < 1.1 mm; 11.5 mm < TTL < 12.2 mm; 1.5 ≤ Fno ≤ 1.6; 5.8 mm < IH ≤ 6 mm; By satisfying the above conditional formula, the optical lens has at least one or more advantages such as a short focal length, an ultra-large field of view angle, a large entrance pupil diameter, a short overall length, a large aperture, a large image plane, low distortion, and low sensitivity.

[0069] In some embodiments, the eight lenses in the optical lens can all be made of plastic or a combination of glass and plastic materials. Preferably, the optical lens of the present invention uses an eight-lens structure with a combination of glass and plastic materials, which can improve thermal stability. Specifically, the first and fifth lenses can be made of glass, while the second, third, fourth, sixth, seventh, and eighth lenses are all made of plastic. The use of a glass-plastic hybrid structure can effectively reduce costs, correct aberrations, reduce size, and provide a more cost-effective optical lens product.

[0070] In some embodiments, the first, second, third, fourth, fifth, sixth, seventh, and eighth lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, the first and fifth lenses in the optical lens provided by this invention can be spherical lenses; the second, third, fourth, sixth, seventh, and eighth lenses can all be aspherical lenses.

[0071] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations:

[0072] ;

[0073] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, and H are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0074] 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.

[0075] Example 1

[0076] Please see Figure 1The 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 S19, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0077] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0078] The second lens L2 has negative optical power, its object side S3 is convex, and its image side S4 is concave.

[0079] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is concave.

[0080] The fourth lens L4 has positive optical power, its object side S7 is concave near the optical axis, and its image side S8 is convex.

[0081] The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side S10 is convex.

[0082] The sixth lens L6 has negative optical power, its object side S11 is concave, and its image side S12 is concave.

[0083] The seventh lens L7 has positive optical power, its object side S13 is convex, and its image side S14 is convex.

[0084] 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.

[0085] The object-side surface S17 and the image-side surface S18 of filter G1 are both planar.

[0086] The imaging plane S19 is a plane.

[0087] The first lens L1 and the fifth lens L5 are glass spherical lenses; the second lens L2, the third lens L3, the fourth lens L4, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are all plastic aspherical lenses.

[0088] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0089] Table 1-1

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

[0095] Figure 2 The field curvature curve of the optical lens 100 in Embodiment 1 is shown, which represents the degree of 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 to 0.05 mm, indicating that the optical lens 100 can effectively correct the field curvature.

[0096] Figure 3 The figure shows the F-Theta distortion curve of the optical lens 100 in Embodiment 1, which represents the F-Theta distortion of light 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 F-Theta distortion of the optical lens is controlled within 0~10%, indicating that the optical lens 100 can correct distortion well.

[0097] Figure 4 The diagram shows the axial aberration curve of the optical lens 100 in Embodiment 1, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -0.02 mm to 0.02 mm, indicating that the optical lens 100 can correct axial aberration well.

[0098] Figure 5 The diagram shows the transverse chromatic aberration curve of the optical lens 100 in Embodiment 1. 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 -1 μm to 5 μm, indicating that the optical lens 100 can effectively correct chromatic aberration.

[0099] Example 2

[0100] Please see Figure 6The figure shows 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 object side surface S7 of the fourth lens L4 is a convex surface; 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] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0105] Table 2-2

[0106]

[0107] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0108] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.1mm to 0.05mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0109] from Figure 8 As can be seen, the F-Theta distortion of the optical lens is controlled within 0~11%, indicating that the optical lens 200 can correct distortion well.

[0110] from Figure 9 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.02mm, indicating that the optical lens 200 can correct the axial aberration well.

[0111] from Figure 10 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 4μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0112] Example 3

[0113] Please see Figure 11The 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 sixth lens L6 and the seventh lens L7 form a cemented lens group; the object side surface S3 of the second lens L2 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0114] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0115] Table 3-1

[0116]

[0117] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0118] Table 3-2

[0119]

[0120] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0121] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.05mm to 0.06mm, indicating that the optical lens 300 can effectively correct the field curvature.

[0122] from Figure 13 As can be seen, the F-Theta distortion of the optical lens is controlled within 0~11%, indicating that the optical lens 300 can correct distortion well.

[0123] from Figure 14 As can be seen, the axial aberration offset is controlled within -0.03mm to 0.02mm, indicating that the optical lens 300 can correct axial aberration well.

[0124] from Figure 15 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 7μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0125] 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.

[0126] Table 4

[0127]

[0128] In summary, the optical lens provided by the present invention adopts an eight-element glass-plastic hybrid structure. 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, giving the lens one or more advantages such as ultra-wide angle, high pixel count, large aperture, low distortion, and high imaging quality.

[0129] 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.

[0130] 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 eight lenses, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with negative optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose image side is concave; A third lens with positive optical power, whose object side is convex and whose image side is concave; A fourth lens with positive optical power, whose image side is convex; A fifth lens with positive optical power, whose object side is convex and whose image side is convex; A sixth lens with negative optical power, whose object side is concave and whose image side is concave; A seventh lens with positive optical power, whose object side is convex and whose image side is convex; An eighth lens with negative optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; Wherein, the true image height IH corresponding to the maximum field angle of the optical lens and the clear aperture semi-diameter CSD11 of the object side of the first lens satisfy: 1.1 < IH / CSD11 ≤ 1.

2.

2. The optical lens according to claim 1, characterized in that, The maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 125° < FOV / Fno < 145°.

3. 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 entrance pupil diameter EPD of the optical lens satisfy: 5.5 < IH / EPD < 6.

4. The optical lens according to claim 1, characterized in that, The f-number Fno of the optical lens and the effective focal length f of the optical lens satisfy: 0.9mm < f / Fno < 1.1mm.

5. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.9 < f / f1 < -3.7; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.9 < f / f2 < -2.

3.

6. The optical lens according to claim 1, characterized in that, The combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: -1.8 < f123 / f < -1.

3.

7. The optical lens according to claim 1, characterized in that, The combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 1.2 < f45678 / f < 1.

5.

8. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens, the curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: -0.6 < f1 / (R1 + R2) < -0.

5.

9. The optical lens according to claim 1, characterized in that, 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: 2.3 < CSD11 / CSD81 < 2.

7.

10. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter CSD11 of the object side of the first lens and the sagitta SAGX11 of the clear aperture semi-diameter of the object side of the first lens satisfy: 2.4 < CSD11 / SAGX11 < 3.2.

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