Optical lens

Abstract

The present invention provides an optical lens having seven lenses, which include, in order from the object side to the imaging surface along the optical axis: a first lens having negative optical power, whose object side and image side are both concave surfaces; a second lens having positive optical power, whose object side and image side are both convex surfaces; a third lens having negative optical power, whose object side is concave and image side is convex; a fourth lens having positive optical power, whose object side and image side are both convex surfaces; a fifth lens having positive optical power, whose object side and image side are both convex surfaces; a sixth lens having negative optical power, whose object side and image side are both concave surfaces; and a seventh lens having positive optical power, whose object side and image side are both convex surfaces. The optical lens provided by the present invention improves the imaging quality of the optical lens, reduces aberrations, and enhances the imaging quality of the optical lens through the reasonable configuration of the surface shapes of each lens and the reasonable matching of the optical powers.

Description

Technical Field

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

[0002] As people's requirements for driving experience continue to increase, automotive optical lenses are increasingly used in intelligent driving, and the status of automotive optical lenses in the automotive-related industries continues to improve.

[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 systems require not only a thin, compact form factor with high pixel count and resolution, but also the ability to produce clear images in low-light conditions. Therefore, developing an optical lens with excellent imaging performance is crucial. Summary of the Invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0005] The present invention provides an optical lens, comprising seven lenses, which include the following lenses in order from the object side to the imaging surface along the optical axis:

[0006] a first lens having negative optical power, wherein both the object-side surface and the image-side surface are concave;

[0007] a second lens having positive refractive power, wherein both the object-side surface and the image-side surface are convex;

[0008] The third lens has a negative optical power, with a concave object-side surface and a convex image-side surface;

[0009] The fourth lens element has positive refractive power, and both the object-side surface and the image-side surface are convex;

[0010] The fifth lens has positive refractive power, and both the object-side surface and the image-side surface are convex;

[0011] a sixth lens element having negative optical power, wherein both the object-side surface and the image-side surface are concave;

[0012] The seventh lens element has positive refractive power, and both the object-side surface and the image-side surface are convex;

[0013] The combined focal length f13 of the first lens, the second lens, and the third lens and the combined focal length f47 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy the following conditions: -0.9 <f13 / f47<-0.6。

[0014] Further preferably, the total optical length TTL of the optical lens and the sum ΣCT of the center thicknesses of the first to seventh lenses along the optical axis satisfy: 0.5<ΣCT / TTL<0.6.

[0015] Further preferably, the semi-aperture d1 of the object side of the first lens, the real image height ih corresponding to the maximum half field angle of the optical lens, and the maximum field angle FOV meet the following conditions: 0.45 <d1 / ih / Tan(FOV / 2)<0.9。

[0016] Further preferably, the effective focal length f of the optical lens and the combined focal length f13 of the first lens, the second lens and the third lens satisfy: -0.9 <f13 / f<-0.5。

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.2 <f1 / f<-1.0。

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 4.0 <f2 / f<6.0。

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -3.0 <f3 / f<-2.5。

[0020] Further preferably, the effective focal length f of the optical lens, the real image height ih corresponding to the maximum half field angle of the optical lens, and the maximum field angle FOV satisfy the following conditions: 0.5 <ih / (f×Tan(FOV / 2))<0.7。

[0021] Further preferably, the maximum field of view FOV and aperture value FNO of the optical lens meet the following requirements: 60° <FOV / FNO<75°。

[0022] Further preferably, the real image height IH and entrance pupil diameter EPD corresponding to the maximum field angle of the optical lens satisfy the following relationship: 2.5 <IH / EPD<3.2。

[0023] The optical lens provided by the present invention improves the imaging quality of the optical lens, reduces aberrations, and improves the imaging quality of the optical lens through the reasonable configuration of the surface shapes of each lens and the reasonable matching of the optical focal length. BRIEF DESCRIPTION OF THE DRAWINGS

[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 with reference to the following drawings, in which:

[0025] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0026] Figure 2 Graph showing the field curvature of the optical lens in Example 1 of the present invention.

[0027] Figure 3 : is the F-Tanθ distortion curve of the optical lens in Example 1 of the present invention.

[0028] Figure 4 This is a relative illumination curve diagram of the optical lens in Example 1 of the present invention.

[0029] Figure 5 This is the MTF curve of the optical lens in Example 1 of the present invention.

[0030] Figure 6 1 is an axial aberration curve diagram of the optical lens in Example 1 of the present invention.

[0031] Figure 7 Graph showing the vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0032] Figure 8 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0033] Figure 9 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0034] Figure 10 : is the F-Tanθ distortion curve of the optical lens in Example 2 of the present invention.

[0035] Figure 11 This is a relative illumination curve diagram of the optical lens in Example 2 of the present invention.

[0036] Figure 12 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

[0037] Figure 13 2 is an axial aberration curve diagram of the optical lens in Example 2 of the present invention.

[0038] Figure 14 Graph showing vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0039] Figure 15 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0040] Figure 16 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0041] Figure 17 : is the F-Tanθ distortion curve of the optical lens in Example 3 of the present invention.

[0042] Figure 18 This is a relative illumination curve diagram of the optical lens in Example 3 of the present invention.

[0043] Figure 19 This is the MTF curve of the optical lens in Example 3 of the present invention.

[0044] Figure 20 4 is an axial aberration curve diagram of the optical lens in Example 3 of the present invention.

[0045] Figure 21 Graph showing vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0046] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0047] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of embodiments of the present application and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0048] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0049] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0050] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0051] It should also be understood that the terms "comprising", "comprises", "having", "contains" and / or "containing", when used in this specification, denote the presence of the stated features, elements and / or components, but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when an expression such as "at least one of..." appears after a list of listed features, it modifies the entire list of listed features rather than an individual element in the list. In addition, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the term "exemplary" is intended to refer to an example or illustration.

[0052] Unless otherwise defined, all terms used herein (including technical and scientific terms) 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 (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0053] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0054] The optical lens of the embodiment of the present invention sequentially includes, along the optical axis from the object side to the imaging surface: a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a filter and a protective glass.

[0055] In some embodiments, the first lens may have a negative focal power, and both its object side and image side are concave surfaces. The second lens may have a positive focal power, and both its object side and image side are convex surfaces. The third lens may have a negative focal power, its object side is a concave surface, and its image side is a convex surface. The fourth lens may have a positive focal power, and both its object side and image side are convex surfaces. The fifth lens may have a positive focal power, and both its object side and image side are convex surfaces. The sixth lens may have a negative focal power, and both its object side and image side are concave surfaces. The seventh lens may have a positive focal power, and both its object side and image side are convex surfaces.

[0056] In some embodiments, the combined focal length f13 of the first lens, the second lens and the third lens and the combined focal length f47 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -0.9 < f13 / f47 < -0.6. Meeting the above range, the front end of the optical lens has a strong light deflection ability, which is beneficial to the incidence of large-angle light into the optical lens, achieving a large field angle and improving the image plane brightness of the optical lens.

[0057] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 5.0. Meeting the above range enables the total length to be controlled within a reasonable range.

[0058] In some embodiments, the effective focal length f of the optical lens, the true image height ih corresponding to the maximum half field angle of the optical lens, and the maximum field angle FOV satisfy: 0.5 < ih / (f × Tan(FOV / 2)) < 0.7. Meeting the above range controls the distortion within a reasonable range.

[0059] In some embodiments, the maximum field angle FOV of the optical lens and the f-number FNO satisfy: 60° < FOV / FNO < 75°. Meeting the above range enables the balance of a large field angle and a large aperture.

[0060] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD satisfy: 2.5 < IH / EPD < 3.2. Meeting the above range ensures high color reproducibility even with a relatively large entrance pupil diameter, and the optical lens can still achieve good imaging performance even in a low-light environment.

[0061] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL satisfy: BFL / f > 1.2. Meeting the above range helps to maintain a long back focal length, which is beneficial for adjusting the power distribution of each lens and provides more optimization space for various aberrations of the optical lens.

[0062] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the true image height IH corresponding to the maximum field angle satisfy: FOV × f / IH > 60°. Meeting the design requirements of a long focal length and a large field angle.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.2 < f1 / f < -1.0. Meeting the above range can endow the first lens with an appropriate negative optical power, which is beneficial for capturing light rays incident at large angles and expanding the field angle of the optical lens.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 4.0 < f2 / f < 6.0. Meeting the above range can endow the second lens with an appropriate positive optical power, which is beneficial for correcting axial aberrations.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -3.0 < f3 / f < -2.5. Meeting the above range can endow the third lens with an appropriate negative optical power, which is beneficial for compensating off-axis aberrations.

[0066] 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 < 1.5. Satisfying the above range can make the fourth lens have an appropriate positive optical power, converge light while reducing the light deflection angle, make the light trend transition smoothly, and at the same time balance various aberrations generated by the optical lens, improving the imaging quality of the optical lens.

[0067] 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 < 1.5. Satisfying the above range can make the fifth lens have an appropriate positive optical power, converge light while reducing the light deflection angle, make the light trend transition smoothly, and improve the imaging quality of the optical lens.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.0 < f6 / f < -0.5. Satisfying the above range can make the sixth lens have an appropriate negative optical power, which is beneficial to balancing the coma generated by the fifth lens and the astigmatism of the lens.

[0069] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.5 < f7 / f < 2.0. Satisfying the above range can make the seventh lens have an appropriate positive optical power, which is beneficial to suppressing the angle of incidence of the marginal field of view on the imaging surface, effectively transmitting more light beams to the imaging surface, and at the same time balancing the aberrations of the optical lens, improving the imaging quality of the optical lens.

[0070] 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 seventh lens along the optical axis respectively satisfy: 0.5 < ∑CT / TTL < 0.6. Satisfying the above range is beneficial to the structural design and production process of the optical lens.

[0071] In some embodiments, the clear aperture radius d1 of the object side surface of the first lens, the true image height ih corresponding to the maximum half field angle of the optical lens, and the maximum field angle FOV satisfy: 0.45 < d1 / ih / Tan(FOV / 2) < 0.9. Satisfying the above range is beneficial to balancing the relationship between the front aperture diameter, field angle and image surface size of the optical lens, and is beneficial to achieving miniaturization. <未见相关内容,无法翻译,保留原文

[0072] In some embodiments, the effective focal length f of the optical lens and the combined focal length f13 of the first lens, the second lens and the third lens satisfy: -0.9 < f13 / f < -0.5. Satisfying the above range, the front lens group of the optical lens adopts a negative lens group, which can effectively increase the field angle and at the same time offset the astigmatism caused by light aggregation, making the light evenly distributed and improving the overall relative illumination of the imaging surface.

[0073] In some embodiments, the fifth lens and the sixth lens can be cemented to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the decentration sensitivity of the optical lens, balance the aberration 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 difficulty of the optical lens processing technology and improving the assembly yield of the optical lens.

[0074] In order to make the system have better optical performance, multiple aspheric lenses are used in the lens. The shape of each aspheric surface of the optical lens satisfies the following equation:

[0075]

[0076] Where z is the distance between the surface and the vertex in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, and A, B, C, D, E, and F are the second-order, fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients, respectively.

[0077] The present invention is further illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0078] Example 1

[0079] See also Figure 1 , shown is a schematic structural diagram of the optical lens provided in Example 1 of the present invention, which includes, along the optical axis from the object side to the imaging surface, 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, a filter G1, and a protective glass G2.

[0080] The first lens L1 has negative refractive power, and its object-side surface S1 and image-side surface S2 are both concave;

[0081] The second lens L2 has positive refractive power, and its object-side surface S3 and image-side surface S4 are both convex;

[0082] The third lens L3 has negative refractive power, its object-side surface S5 is concave, and its image-side surface S6 is convex;

[0083] Aperture ST;

[0084] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0085] The fifth lens L5 has positive refractive power, and its object-side surface S9 and image-side surface S10 are both convex;

[0086] The sixth lens L6 has negative refractive power, and its object-side surface S10 and image-side surface S11 are both concave;

[0087] The fifth lens L5 and the sixth lens L6 form a cemented lens group. That is, the cemented surface between the image-side surface of the fifth lens L5 and the object-side surface of the sixth lens L6 is S10.

[0088] The seventh lens L7 has positive refractive power, and its object-side surface S12 and image-side surface S13 are both convex;

[0089] The object-side surface S14 and the image-side surface S15 of the filter G1 are both flat surfaces;

[0090] The object side surface S16 and the image side surface S17 of the protective glass G2 are both flat surfaces;

[0091] The imaging surface S18 is a plane.

[0092] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0093] Table 1-1

[0094]

[0095]

[0096] The surface parameters of the aspheric lens of the optical lens in Example 1 are shown in Table 1-2.

[0097] Table 1-2

[0098] Face number K A B C D E F S7 2.28E+00 0.00E+00 1.47E-04 2.17E-06 -4.69E-07 1.92E-08 -1.70E-10 S8 -2.59E+00 0.00E+00 -2.97E-04 -3.52E-06 9.32E-07 -4.42E-08 8.39E-10 S12 -1.65E+00 0.00E+00 8.14E-04 -1.53E-05 4.26E-08 9.87E-09 -4.23E-10 S13 1.68E+00 0.00E+00 9.13E-04 -1.02E-05 1.31E-06 -4.55E-08 3.30E-10

[0099] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 shown.

[0100] Figure 2The field curvature curves for Example 1 are shown, representing 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 angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within a range of -0.06mm to 0.04mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0101] Figure 3 The F-Tanθ distortion curve for Example 1 shows the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging surface. 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 a range of -8% to 0%, and the image compression in the edge angle area is relatively smooth, effectively improving the clarity of the expanded image.

[0102] Figure 4 The relative illumination curve of Example 1 is shown, which represents the relative illumination values ​​at different field 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.

[0103] Figure 5 The MTF (Modulation Transfer Function) curve for Example 1 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.4 across the entire field of view. Within the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0104] Figure 6 The following graph shows the axial aberration curve for Example 1, which represents the aberration on the optical axis at the imaging plane for each wavelength. 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 graph, the offset of the axial aberration is controlled within a range of -30 μm to 15 μm, indicating that the optical lens can effectively correct axial aberration.

[0105] Figure 7The vertical chromatic aberration curve for Example 1 is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within a range of -1 μm to 2 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0106] Example 2

[0107] See also Figure 8 , shown is a schematic structural diagram of the optical lens provided in Example 2 of the present invention. Compared with Example 1, this embodiment is different mainly in optical parameters such as the curvature radius of each lens surface, lens thickness, aspheric surface parameters, etc.

[0108] The relevant parameters of each lens in the optical lens in Example 2 are shown in Table 2-1.

[0109] Table 2-1

[0110]

[0111] The surface parameters of the aspheric lens of the optical lens in Example 2 are shown in Table 2-2.

[0112] Table 2-2

[0113] Face number K A B C D E F S7 1.55E+00 0.00E+00 7.31E-05 1.33E-06 -4.77E-07 2.34E-08 -2.49E-10 S8 -2.18E+00 0.00E+00 -1.78E-04 -3.88E-06 8.85E-07 -4.36E-08 8.78E-10 S12 -1.21E+00 0.00E+00 7.79E-04 -1.65E-05 3.18E-07 -5.42E-09 -6.23E-11 S13 2.55E+00 0.00E+00 1.06E-03 -4.37E-06 9.98E-07 -3.24E-08 2.06E-10

[0114] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 shown.

[0115] Figure 9 The field curvature curves for Example 2 are shown, representing 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 angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within a range of -0.08mm to 0.06mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0116] Figure 10The F-Tanθ distortion curve for Example 2 shows the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging surface. 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 a range of -10% to 0%, and the image compression in the edge angle area is relatively smooth, effectively improving the clarity of the expanded image.

[0117] Figure 11 The relative illumination curve of Example 2 is shown, which represents the relative illumination values ​​at different field angles on the imaging surface. 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.

[0118] Figure 12 The MTF (Modulation Transfer Function) curve for Example 2 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.3 across the entire field of view. Within the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0119] Figure 13 The following graph shows the axial aberration curve for Example 2, which represents the aberration on the optical axis at the imaging plane for each wavelength. 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 graph, the offset of the axial aberration is controlled within a range of -20μm to 25μm, indicating that the optical lens can effectively correct axial aberration.

[0120] Figure 14 The vertical chromatic aberration curve for Example 2 is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within a range of -1 μm to 2 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0121] Example 3

[0122] See also Figure 15, shown is a schematic structural diagram of the optical lens provided in Example 3 of the present invention. Compared with Example 1, this embodiment is different mainly in optical parameters such as the curvature radius of each lens surface, lens thickness, aspheric surface parameters, etc.

[0123] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0124] Table 3-1

[0125]

[0126] The surface parameters of the aspheric lens of the optical lens in Example 3 are shown in Table 3-2.

[0127] Table 3-2

[0128] Face number K A B C D E F S7 1.73E+00 0.00E+00 1.22E-04 2.27E-06 -4.54E-07 1.93E-08 -1.73E-10 S8 -2.41E+00 0.00E+00 -2.86E-04 -3.28E-06 9.13E-07 -4.41E-08 8.59E-10 S12 -2.10E+00 0.00E+00 7.92E-04 -1.46E-05 2.11E-08 8.29E-09 -4.17E-10 S13 1.92E+00 0.00E+00 9.01E-04 -8.95E-06 1.19E-06 -4.75E-08 3.93E-10

[0129] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 、 Figure 21 shown.

[0130] Figure 16 The field curvature curves for Example 3 are shown, showing 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 angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within a range of -0.06mm to 0.04mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0131] Figure 17 The F-Tanθ distortion curve for Example 3 is shown. It represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging surface. 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 a range of -10% to 0%, and the image compression in the edge angle area is relatively smooth, effectively improving the clarity of the expanded image.

[0132] Figure 18 The relative illumination curve of Example 3 is shown, which shows the relative illumination values ​​at different field 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.

[0133] Figure 19 The MTF (Modulation Transfer Function) curve for Example 3 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.3 across the entire field of view. Within the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0134] Figure 20 The following graph shows the axial aberration curve for Example 3, which represents the aberration on the optical axis at the imaging plane for each wavelength. 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 graph, the offset of the axial aberration is controlled within a range of -15μm to 30μm, indicating that the optical lens can effectively correct axial aberration.

[0135] Figure 21 The vertical chromatic aberration curve for Example 3 is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within a range of -1 μm to 2 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0136] Please refer to Table 4, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value FNO, real image height IH corresponding to the maximum field of view angle, chief ray incidence angle CRA, and maximum field of view angle FOV of the optical lens, as well as the numerical values ​​corresponding to each conditional expression in each embodiment.

[0137] Table 4

[0138] Parameters and Conditionals Example 1 Example 2 Example 3 f(mm) 6.22 5.91 6.25 FOV(°) 102.00 120.00 102.00 EPD(mm) 3.79 3.61 3.81 TTL(mm) 28.91 28.12 30.61 FNO 1.64 1.64 1.64 ih(mm) 5.14 5.44 5.10 CRA(°) 13.54 14.14 14.51 BFL(mm) 8.52 7.54 8.20 d1 4.59 4.65 5.37 TTL / f 4.65 4.76 4.90 TTL / IH 2.81 2.58 3.00 ih / (f×Tan(FOV / 2)) 0.67 0.53 0.66 FOV / FNO(°) 62.20 73.17 62.20 IH / EPD 2.71 3.02 2.68 BFL / f 1.37 1.28 1.31 FOV×f / IH(°) 61.71 65.20 62.44 f1 / f -1.00 -1.05 -1.01 f2 / f 4.43 5.94 4.77 f3 / f -2.63 -2.69 -2.60 f4 / f 1.39 1.41 1.39 f5 / f 1.26 1.25 1.25 f6 / f -0.90 -0.87 -0.88 f7 / f 1.76 1.66 1.75 ∑CT / TTL 0.59 0.61 0.61 d1 / ih / Tan(FOV / 2) 0.72 0.49 0.85 f13 / f -0.79 -0.79 -0.77 f13 / f47 -0.75 -0.71 -0.73

[0139] In summary of the above embodiments, the optical lens provided by the present invention improves the imaging quality of the optical lens, reduces aberrations, and improves the imaging quality of the optical lens through the reasonable configuration of the surface shapes of each lens and the reasonable matching of the optical power.

[0140] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0141] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, comprising seven lenses, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: a first lens having negative optical power, wherein both the object-side surface and the image-side surface are concave; a second lens having positive refractive power, wherein both the object-side surface and the image-side surface are convex; The third lens has a negative optical power, with a concave object-side surface and a convex image-side surface; The fourth lens element has positive refractive power, and both the object-side surface and the image-side surface are convex; The fifth lens has positive refractive power, and both the object-side surface and the image-side surface are convex; a sixth lens element having negative optical power, wherein both the object-side surface and the image-side surface are concave; The seventh lens element has positive refractive power, and both the object-side surface and the image-side surface are convex; The combined focal length f13 of the first lens, the second lens, and the third lens and the combined focal length f47 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy the following conditions: -0.9 <f13 / f47<-0.6。 2. The optical lens according to claim 1, wherein: The total optical length TTL of the optical lens and the sum ΣCT of the center thicknesses of the first to seventh lenses along the optical axis respectively satisfy the following: 0.5<ΣCT / TTL<0.

6.

3. The optical lens according to claim 1, wherein: The semi-aperture d1 of the object side of the first lens, the real image height ih corresponding to the maximum half field angle of the optical lens, and the maximum field angle FOV meet the following requirements: 0.45 <d1 / ih / Tan(FOV / 2)<0.9。 4. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the combined focal length f13 of the first lens, the second lens and the third lens satisfy: -0.9 <f13 / f<-0.5。 5. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.2 <f1 / f<-1.0。 6. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 4.0 <f2 / f<6.0。 7. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -3.0 <f3 / f<-2.5。 8. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens, the real image height ih corresponding to the maximum half field of view angle of the optical lens, and the maximum field of view FOV meet the following requirements: 0.5 <ih / (f×Tan(FOV / 2))<0.7。 9. The optical lens according to claim 1, wherein: The maximum field of view FOV and aperture value FNO of the optical lens meet the following requirements: 60° <FOV / FNO<75°。 10. The optical lens according to claim 1, wherein: The maximum field of view of the optical lens corresponds to the true image height IH and the entrance pupil diameter EPD satisfying: 2.5 <IH / EPD<3.2。

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