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 an image side of the first lens is a concave surface; a second lens with positive optical power, wherein an image side of the second lens is a convex surface; a third lens with negative optical power, wherein an object side of the third lens is a convex surface, and an image side of the third lens is a concave surface; a fourth lens with positive optical power, wherein both an object side and an image side of the fourth lens are convex surfaces; a fifth lens with positive optical power, wherein both an object side and an image side of the fifth lens are convex surfaces; a sixth lens with negative optical power, wherein both an object side and an image side of the sixth lens are concave surfaces; a seventh lens with negative optical power; and an eighth lens with positive optical power. The optical lens provided by the application improves the imaging quality of the optical lens, reduces aberration and improves the imaging quality of the optical lens through reasonable configuration of the surface types of the lenses and reasonable matching of the optical powers.

Description

Technical Field

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

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure driver safety. Existing ADAS lenses not only require a slim and compact design with high pixel count and high resolution, but also need to produce clear images in low-light conditions. Therefore, it is necessary to develop an optical lens with excellent imaging performance. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An optical lens comprising eight lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0007] The first lens with negative optical power has a concave image-side surface.

[0008] A second lens with positive optical power has a convex image-side surface.

[0009] A third lens with negative optical power has a convex object side and a concave image side.

[0010] The fourth lens with positive optical power has convex surfaces on both its object side and image side.

[0011] The fifth lens with positive optical power has convex surfaces on both its object side and image side.

[0012] The sixth lens has negative optical power, and both its object-side and image-side surfaces are concave.

[0013] A seventh lens with negative optical power;

[0014] An eighth lens with positive optical power;

[0015] The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy the condition: f3 / f < -3.0.

[0016] Further preferably, the total optical length (TTL) and effective focal length (f) of the optical lens satisfy: TTL / f < 5.5.

[0017] Further preferably, the effective focal length f, the maximum field of view FOV, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.55 < (IH / 2) / (f×tan(FOV / 2)) < 0.9.

[0018] Further preferably, the maximum field of view (FOV) of the optical lens and the aperture value (FNO) satisfy: 35° <FOV / FNO<80°。

[0019] Further preferably, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view satisfy: 1.4 <IH / f<2.2。

[0020] Further preferably, the effective focal length f and the optical back focal length BFL of the optical lens satisfy: 0.4 <BFL / f<1.0。

[0021] Further preferably, the maximum field of view (FOV) of the optical lens and the effective focal length (f) satisfy: 8.0 <FOV / f<16.0。

[0022] Further preferably, the object-side radius of curvature R1 of the first lens and the image-side radius of curvature R2 of the first lens satisfy: 0.5 < (R1 + R2) / (R1 - R2) < 1.5.

[0023] Further preferably, the object-side radius of curvature R5 of the third lens and the image-side radius of curvature R6 of the third lens satisfy: (R5+R6) / (R5-R6)>4.0.

[0024] Further preferably, the total optical length TTL of the optical lens and the sum of the center thicknesses of the first to eighth lenses along the optical axis, ∑CT, satisfy: 0.5 < ∑CT / TTL < 0.65.

[0025] The optical lens provided by this invention improves the imaging quality, reduces aberrations, and enhances the imaging performance of the optical lens through the reasonable configuration of each lens surface shape and the reasonable matching of optical power. Attached Figure Description

[0026] 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:

[0027] Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0028] Figure 2This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 3 This is the F-Tanθ distortion curve of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 4 This is a relative illumination curve of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 5 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0032] Figure 6 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0033] Figure 7 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0034] Figure 8 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0035] Figure 9 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0036] Figure 10 This is the F-Tanθ distortion curve of the optical lens in Embodiment 2 of the present invention.

[0037] Figure 11 This is a relative illumination curve of the optical lens in Embodiment 2 of the present invention.

[0038] Figure 12 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0039] Figure 13 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0040] Figure 14 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0041] Figure 15 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0042] Figure 16 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0043] Figure 17 This is the F-Tanθ distortion curve of the optical lens in Embodiment 3 of the present invention.

[0044] Figure 18 This is a relative illumination curve of the optical lens in Embodiment 3 of the present invention.

[0045] Figure 19 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0046] Figure 20 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0047] Figure 21 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0048] Figure 22 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0049] Figure 23 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0050] Figure 24 This is the F-Tanθ distortion curve of the optical lens in Embodiment 4 of the present invention.

[0051] Figure 25 This is a relative illumination curve of the optical lens in Embodiment 4 of the present invention.

[0052] Figure 26 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0053] Figure 27 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0054] Figure 28 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0055] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] The optical lens of this invention comprises, in sequence along the optical axis from the object side to the imaging plane: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a filter, and a protective glass. An aperture stop is provided between the third and fourth lenses, or between the second and third lenses, or between the first and second lenses.

[0064] In some embodiments, the first lens may have a negative optical power, and its image side is concave. The second lens may have a positive optical power, and its image side is convex. The third lens may have a negative optical power, its object side is convex, and its image side is concave. The fourth lens may have a positive optical power, and both its object side and image side are convex. The fifth lens may have a positive optical power, and both its object side and image side are convex. The sixth lens may have a negative optical power, and both its object side and image side are concave. The seventh lens may have a negative optical power. The eighth lens may have a positive optical power.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: f3 / f < -3.0. Meeting the above range is beneficial to the smooth transition of light, facilitating the correction of astigmatism and field curvature, and improving the imaging quality of the optical lens.

[0066] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f satisfy: TTL / f < 5.5. Meeting the above range can effectively limit the length of the lens.

[0067] In some embodiments, the effective focal length f, the maximum field angle FOV, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.55 < (IH / 2) / (f × tan(FOV / 2)) < 0.9. Meeting the above requirements indicates that the optical distortion of the optical lens is well controlled, improving the resolution of the optical lens.

[0068] In some embodiments, the maximum field angle FOV of the optical lens and the f-number FNO satisfy: 35° < FOV / FNO < 80°. Meeting the above requirements is beneficial to expanding the field angle of the optical lens and increasing the aperture of the optical lens, facilitating the optical lens to obtain more scene information, meeting the requirements of large-range detection, and being beneficial to improving the problem of rapid decline of the relative brightness of the edge field of view, thus also being beneficial to obtaining more scene information.

[0069] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 1.4 < IH / f < 2.2. Meeting the above range can achieve both wide-angle characteristics to meet the requirements of large-range shooting and large-image-plane characteristics to improve the imaging quality of the optical lens.

[0070] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL satisfy: 0.4 < BFL / f < 1.0. Meeting the above range can reduce the interference of aberrations such as spherical aberration and coma, improve the resolution and clarity of imaging, and improve the stability of the optical lens.

[0071] In some embodiments, the maximum field of view FOV of the optical lens and the effective focal length f satisfy: 8.0 < FOV / f < 16.0. Meeting the above range enables the optical lens to capture more distant targets.

[0072] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.5 < (R1 + R2) / (R1 - R2) < 1.5. Meeting the above range can control the light direction, reduce spherical aberration, correct coma, increase light utilization rate, and improve stability.

[0073] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: (R5 + R6) / (R5 - R6) > 4.0. Meeting the above range can converge the marginal field light rays, which helps to optimize the imaging performance under low light conditions and provide better image brightness and contrast.

[0074] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the eighth lens along the optical axis satisfy: 0.5 < ∑CT / TTL < 0.65. Meeting the above range can compress the total length of the optical system, making the structure of the system more compact.

[0075] In some embodiments, the maximum field of view FOV of the optical lens, the true image height IH corresponding to the maximum field of view, and the clear aperture D1 of the object side surface of the first lens satisfy: 0.5 < D1 / IH / tan(FOV / 2) < 1.9. Meeting the above range can ensure the balance between the size of the optical lens, the field of view, and the image plane.

[0076] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < f1 / f < -1.0. Meeting the above range can make the first lens have an appropriate positive optical power, and can balance the relationship between the working aperture of the first lens, the image plane size, and the field of view.

[0077] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 3.0 < f2 / f < 10.0. Meeting the above range can make the second lens have an appropriate positive optical power, make the light trend stable, and is beneficial to balancing the aberration brought by the negative refractive power of the first lens, that is, it can correct the marginal aberration of the optical lens and improve the imaging resolution

[0078] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.0 < f4 / f < 2.5. Meeting the above range can make the fourth lens have an appropriate positive optical power, which is beneficial to improving the light converging ability of the optical lens, and at the same time can balance the aberration of the optical lens and improve the imaging quality of the optical lens.

[0079] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.0 < f5 / f < 2.0. Satisfying the above range can make the fifth lens have an appropriate positive optical power, which is beneficial to improving the light converging ability of the optical lens. At the same time, it can balance the aberration of the optical lens and improve the imaging quality of the optical lens.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.0 < f6 / f < -0.5. Satisfying the above range can make the sixth lens have an appropriate negative optical power, enabling the light trend to transition smoothly and enhancing the imaging quality of the optical lens.

[0081] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: f7 / f < -1.0. Satisfying the above range can make the seventh lens have a negative optical power, which is beneficial to increasing the imaging area of the optical lens and enhancing the imaging quality of the optical lens.

[0082] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: f8 / f > 1.0. Satisfying the above range can make the eighth lens have a positive optical power, balance various aberrations, and enhance the imaging quality of the optical lens.

[0083] In some embodiments, the fifth lens and the sixth lens can be glued together to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and enhance 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.

[0084] To make the system have better optical performance, multiple aspherical lenses are used in the lens. The aspherical surface shapes of the optical lens satisfy the following equation:

[0085]

[0086] where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and A, B, C, D, E, F are the surface coefficients of the second order, fourth order, sixth order, eighth order, tenth order, and twelfth order respectively.

[0087] 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.

[0088] Example 1

[0089] Please see Figure 1 The diagram shown is a schematic diagram of the structure of the optical lens provided in Embodiment 1 of the present invention. The optical lens includes, in sequence along the optical axis from the object side to the imaging plane: 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, a filter G1, and a protective glass G2.

[0090] The first lens L1 has negative optical power, and its object side S1 and image side S2 are both concave surfaces.

[0091] The second lens L2 has positive optical power, and its object side surface S3 and image side surface S4 are both convex surfaces.

[0092] The third lens L3 has negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0093] Aperture ST;

[0094] The fourth lens L4 has positive optical power, and both its object-side surface S7 and image-side surface S8 are convex.

[0095] The fifth lens L5 has positive optical power, and both its object side S9 and image side S10 are convex surfaces;

[0096] The sixth lens L6 has negative optical power, and both its object-side surface S10 and image-side surface S11 are concave.

[0097] The fifth lens L5 and the sixth lens L6 form a cemented lens group, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10.

[0098] The seventh lens L7 has negative optical power, with its object-side surface S12 being concave and its image-side surface S13 being convex.

[0099] The eighth lens L8 has positive optical power, and both its object-side surface S14 and image-side surface S15 are convex.

[0100] The object-side surface S16 and the image-side surface S17 of filter G1 are both planar.

[0101] The object side S18 and image side S19 of the protective glass G2 are both flat.

[0102] The imaging plane S20 is a plane.

[0103] The relevant parameters of each lens in the optical lens of Example 1 are shown in Table 1-1.

[0104] Table 1-1

[0105]

[0106]

[0107] The surface profile parameters of the aspherical lens in Example 1 are shown in Table 1-2.

[0108] Table 1-2

[0109] Face number K A B C D E F S5 -1.63E+00 0.00E+00 -7.15E-04 6.07E-06 -1.23E-07 2.40E-09 -7.81E-12 S6 -5.94E-02 0.00E+00 -1.51E-03 1.37E-05 -5.47E-07 1.04E-08 -1.38E-10 S7 -3.03E-01 0.00E+00 -1.98E-04 8.63E-06 -3.33E-07 8.70E-09 -8.44E-11 S8 1.85E+00 0.00E+00 2.70E-04 7.37E-06 -1.15E-07 6.57E-09 -6.77E-11 S14 1.81E-01 0.00E+00 2.65E-04 3.31E-06 -6.84E-08 1.14E-09 -4.98E-12 S15 1.07E+00 0.00E+00 5.68E-04 5.18E-06 -3.12E-09 -7.93E-10 7.78E-12

[0110] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 As shown.

[0111] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.08 mm to 0.04 mm, indicating that the optical lens can effectively correct the field curvature.

[0112] Figure 3 The F-Tanθ distortion curve of Example 1 is shown, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -40% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0113] Figure 4The relative illumination curves for Example 1 are shown, representing the relative illumination values ​​at different field-of-view angles on the imaging plane. The horizontal axis represents the half-field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 70% at the maximum half-field angle, indicating that the optical lens has good relative illumination.

[0114] Figure 5 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.4 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0115] Figure 6 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -15μm to 10μm, indicating that the optical lens can correct axial aberration well.

[0116] Figure 7 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.55 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 diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -2 μm to 3 μm, indicating that the optical lens can effectively correct chromatic aberration at the edges of the field of view and the secondary spectrum of the entire image plane.

[0117] Example 2

[0118] Please see Figure 8 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 2 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1. The main difference is that the object side surface S1 of the first lens L1 is a convex surface, and the optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0119] The relevant parameters of each lens in the optical lens of Example 2 are shown in Table 2-1.

[0120] Table 2-1

[0121]

[0122]

[0123] The surface profile parameters of the aspherical lens in Example 2 are shown in Table 2-2.

[0124] Table 2-2

[0125] Face number K A B C D E F S5 2.71E+00 0.00E+00 -5.76E-04 3.66E-06 9.33E-08 1.44E-10 -5.58E-12 S6 -2.50E-02 0.00E+00 -1.05E-03 3.09E-05 -4.69E-07 -4.05E-09 2.37E-10 S7 2.87E-01 0.00E+00 -8.71E-05 9.89E-06 3.62E-07 4.13E-08 -3.92E-10 S8 -6.42E+00 0.00E+00 5.11E-04 -9.09E-06 5.87E-07 8.29E-08 -2.64E-09 S14 1.23E+01 0.00E+00 6.87E-04 1.35E-05 -5.61E-08 1.03E-09 -1.34E-10 S15 -8.95E+00 0.00E+00 7.68E-04 2.75E-05 7.40E-07 -2.88E-08 -1.31E-10

[0126] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 9 , Figure 10 , Figure 11 , Figure 12 , Figure 13 , Figure 14 As shown.

[0127] Figure 9 The field curvature curve of Example 2 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.04 mm to 0.02 mm, indicating that the optical lens can effectively correct the field curvature.

[0128] Figure 10 The F-Tanθ distortion curves for Example 2 are shown, representing the F-Tanθ distortion of different wavelengths of light at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -15% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0129] Figure 11 The relative illumination curves for Example 2 are shown, representing the relative illumination values ​​at different field-of-view angles on the imaging plane. The horizontal axis represents the half-field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 70% at the maximum half-field angle, indicating that the optical lens has good relative illumination.

[0130] Figure 12The MTF (Modulation Transfer Function) curve of Example 2 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.4 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0131] Figure 13 The axial aberration curve of Example 2 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -5μm to 10μm, indicating that the optical lens can correct axial aberration well.

[0132] Figure 14 The diagram shows the transverse chromatic aberration curves for Example 2, representing the chromatic aberration of each wavelength relative to the center wavelength (0.55 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 diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1 μm to 2 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0133] Example 3

[0134] Please see Figure 15 The figure shows a schematic diagram of the optical lens provided in Embodiment 3 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1. The main difference is that the aperture ST is located between the second lens L2 and the third lens L3. The object side surface S3 of the second lens L2 is concave, and the object side surface S14 of the eighth lens L8 is concave. The optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0135] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0136] Table 3-1

[0137]

[0138]

[0139] The surface profile parameters of the aspherical lens in Example 3 are shown in Table 3-2.

[0140] Table 3-2

[0141] Face number K A B C D E F S5 -8.57E+00 0.00E+00 -2.73E-04 -5.23E-06 -1.45E-07 6.59E-09 -4.88E-11 S6 -7.90E+00 0.00E+00 -1.93E-04 -1.18E-05 8.84E-08 2.25E-09 -2.45E-11 S7 -1.00E+00 0.00E+00 1.11E-04 2.40E-07 -8.00E-09 1.28E-09 -1.91E-11 S8 -8.63E+00 0.00E+00 -4.10E-04 1.02E-05 5.54E-08 -2.07E-09 3.41E-12 S14 1.76E+01 0.00E+00 -1.70E-04 -1.52E-05 2.19E-07 -1.08E-08 1.58E-10 S15 8.67E+00 0.00E+00 1.62E-04 -1.06E-05 1.46E-07 -3.63E-09 6.94E-11

[0142] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 16 , Figure 17 , Figure 18 , Figure 19 , Figure 20 , Figure 21 As shown.

[0143] Figure 16 The field curvature curve of Example 3 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.12 mm to 0.06 mm, indicating that the optical lens can effectively correct the field curvature.

[0144] Figure 17 The F-Tanθ distortion curve of Example 3 is shown, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -50% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0145] Figure 18 The relative illumination curves for Example 3 are shown, representing the relative illumination values ​​at different field-of-view angles on the imaging plane. The horizontal axis represents the half-field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 60% at the maximum half-field angle, indicating that the optical lens has good relative illumination.

[0146] Figure 19 The MTF (Modulation Transfer Function) curve of Example 3 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.2 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0147] Figure 20The axial aberration curve of Example 3 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -40μm to 20μm, indicating that the optical lens can correct axial aberration well.

[0148] Figure 21 The diagram shows the transverse chromatic aberration curves for Example 3, representing the chromatic aberration of each wavelength relative to the center wavelength (0.55 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 diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3 μm to 3 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0149] Example 4

[0150] Please see Figure 22 The figure shows a schematic diagram of the optical lens provided in Embodiment 4 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1. The main difference is that the aperture ST is located between the first lens L1 and the second lens L2, the object side S12 of the seventh lens L7 is convex, the image side S13 of the seventh lens L7 is concave, and the image side S15 of the eighth lens L8 is concave. The optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

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

[0152] Table 4-1

[0153]

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

[0155] Table 4-2

[0156] Face number K A B C D E F S5 8.45E+00 0.00E+00 -3.46E-04 -4.22E-07 -3.76E-08 4.42E-10 -2.99E-12 S6 -8.57E+00 0.00E+00 -9.55E-05 -3.74E-06 5.36E-09 3.21E-10 -1.22E-12 S7 3.35E-01 0.00E+00 -2.28E-05 -1.03E-06 -6.47E-09 4.97E-10 -4.22E-12 S8 -7.34E-01 0.00E+00 5.45E-05 2.76E-07 1.90E-08 -1.10E-10 -1.10E-12 S12 0.00E+00 0.00E+00 -1.84E-04 1.08E-05 -1.70E-07 8.26E-10 -4.04E-12 S13 0.00E+00 0.00E+00 -1.60E-03 -1.43E-05 5.65E-07 -4.09E-09 -2.37E-11 S14 1.94E+00 0.00E+00 -5.61E-05 -5.11E-05 4.71E-07 1.50E-08 -2.90E-10 S15 2.98E+01 0.00E+00 1.40E-03 -1.85E-05 1.13E-07 2.30E-08 -4.69E-10

[0157] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 23 , Figure 24 , Figure 25 , Figure 26 , Figure 27 , Figure 28 As shown.

[0158] Figure 23The field curvature curve of Example 4 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.08 to 0.04 mm, indicating that the optical lens can effectively correct the field curvature.

[0159] Figure 24 The F-Tanθ distortion curves for Example 4 are shown, representing the F-Tanθ distortion of different wavelengths of light at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -15% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0160] Figure 25 The relative illumination curves for Example 4 are shown, representing the relative illumination values ​​at different field-of-view angles on the imaging plane. The horizontal axis represents the half-field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 60% at the maximum half-field angle, indicating that the optical lens has good relative illumination.

[0161] Figure 26 The MTF (Modulation Transfer Function) curve of Example 4 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.3 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0162] Figure 27 The axial aberration curve of Example 4 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -20μm to 15μm, indicating that the optical lens can correct axial aberration well.

[0163] Figure 28The diagram shows the transverse chromatic aberration curves for Example 4, representing the chromatic aberration of each wavelength relative to the center wavelength (0.55 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 diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3 μm to 5 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0164] Please refer to Table 5 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, principal ray incident angle CRA, object-side aperture D1 of the first lens, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0165] Table 5

[0166] Parameters and conditional expressions Example 1 Example 2 Example 3 Example 4 f(mm) 7.98 6.86 7.92 9.01 FOV (°) 106.00 80.00 120.00 80.00 EPD (mm) 4.98 3.43 4.95 6.44 TTL(mm) 42.00 35.28 42.46 41.82 FNO 1.60 2.00 1.60 1.40 IH(mm) 13.82 10.19 16.13 13.00 CRA(°) 20.00 20.00 21.79 18.33 BFL (mm) 5.18 3.03 7.54 7.43 D1(mm) 10.77 14.86 17.18 12.88 TTL / f 5.27 5.14 5.36 4.64 (IH / 2) / (f×tan(FOV / 2)) 0.65 0.88 0.59 0.86 FOV / FNO 66.25 40.00 75.00 57.14 IH / f 1.73 1.48 2.04 1.44 BFL / f 0.65 0.44 0.95 0.82 FOV / f 13.29 11.65 15.15 8.88 f1 / f -1.16 -1.51 -1.24 -1.13 f2 / f 3.84 4.70 7.26 4.45 f3 / f -5.57 -225.24 -26.51 -13.32 f4 / f 1.44 1.53 1.92 1.84 f5 / f 1.35 1.26 1.43 1.28 f6 / f -1.26 -0.99 -1.46 -0.89 f7 / f -1.62 -1.43 -12.57 -16.60 f8 / f 1.57 1.54 6.29 1.70 (R1+R2) / (R1-R2) 0.78 1.40 0.98 0.56 (R5+R6) / (R5-R6) 5.07 17.91 14.73 5.15 ∑CT / TTL 0.54 0.50 0.50 0.61 D1 / IH / tan(FOV / 2) 0.59 1.74 0.61 1.18

[0167] In summary, the optical lens provided by the present invention improves the imaging quality, reduces aberrations, and enhances the imaging performance of the optical lens through the reasonable configuration of each lens surface shape and the reasonable matching of optical power.

[0168] 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.

[0169] 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, Along the optical axis from the object side to the imaging plane, the following are included in sequence: The first lens with negative optical power has a concave image-side surface. A second lens with positive optical power has a convex image-side surface. A third lens with negative optical power has a convex object side and a concave image side. The fourth lens with positive optical power has convex surfaces on both its object side and image side. The fifth lens with positive optical power has convex surfaces on both its object side and image side. The sixth lens has negative optical power, and both its object-side and image-side surfaces are concave. A seventh lens with negative optical power; An eighth lens with positive optical power; The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy the following condition: -225.24 ≤ f3 / f ≤ -5.57; The maximum field of view (FOV) of the optical lens, the true image height (IH) corresponding to the maximum field of view, and the object-side aperture (D1) of the first lens satisfy the following condition: 0.5 <D1 / IH / tan(FOV / 2)<1.9; The effective focal length f and the optical back focal length BFL of the optical lens satisfy: 0.4 <BFL / f<1.0; The object-side radius of curvature R5 and the image-side radius of curvature R6 of the third lens satisfy the following condition: 5.07≤(R5+R6) / (R5-R6)≤17.

91.

2. The optical lens according to claim 1, characterized in that, The total optical length (TTL) and effective focal length (f) of the optical lens satisfy the condition: 4.64 ≤ TTL / f < 5.

5.

3. The optical lens according to claim 1, characterized in that, The effective focal length f, maximum field of view FOV, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy the following condition: 0.55 < (IH / 2) / (f × tan(FOV / 2)) < 0.

9.

4. The optical lens according to claim 1, characterized in that, The maximum field of view (FOV) and aperture value (FNO) of the optical lens satisfy: 35° <FOV / FNO<80°。 5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view satisfy: 1.4 <IH / f<2.2。 6. The optical lens according to claim 1, characterized in that, The effective focal length f and the optical back focal length BFL of the optical lens satisfy the following condition: 0.44≤BFL / f≤0.

95.

7. The optical lens according to claim 1, characterized in that, The maximum field of view (FOV) and effective focal length (f) of the optical lens satisfy: 8.0 <FOV / f<16.0。 8. The optical lens according to claim 1, characterized in that, The object-side radius of curvature R1 of the first lens and the image-side radius of curvature R2 of the first lens satisfy: 0.5 < (R1 + R2) / (R1 - R2) < 1.

5.

9. The optical lens according to claim 1, characterized in that, The maximum field of view (FOV) of the optical lens, the true image height (IH) corresponding to the maximum field of view, and the light transmission aperture (D1) of the object side of the first lens satisfy the following condition: 0.59 ≤ D1 / IH / tan(FOV / 2) ≤ 1.

74.

10. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens and the sum of the center thicknesses of the first lens to the eighth lens along the optical axis, ∑CT, satisfy the condition: 0.5 < ∑CT / TTL < 0.65.

Images