Optical lens

Abstract

The application provides an optical lens, which comprises seven lenses in sequence along an optical axis from an object side to an imaging surface, and the seven lenses comprise: a first lens with negative optical power, wherein the object side surface is a convex surface and the image side surface is a concave surface; a second lens with negative optical power, wherein the object side surface is a convex surface and the image side surface is a concave surface; a third lens with positive optical power, wherein the object side surface is a concave surface and the image side surface is a convex surface; a fourth lens with negative optical power, wherein the object side surface is a concave surface and the image side surface is a convex surface; a fifth lens with negative optical power, wherein the object side surface is a convex surface and the image side surface is a concave surface; a sixth lens with positive optical power, wherein the object side surface and the image side surface are both convex surfaces; and a seventh lens with negative optical power, wherein the object side surface is a concave surface and the image side surface is a convex surface. 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] The present application relates to the technical field of imaging lenses, in particular to an optical lens. BACKGROUND

[0002] With the continuous improvement of people's requirements for driving experience, vehicle application type optical lenses are used more and more in intelligent driving, and the position of vehicle optical lenses in the automobile industry is continuously improved.

[0003] The panoramic surround view system sets up multiple surround view cameras around the vehicle, which can cover all the field of view ranges around the vehicle. The view angles of the multiple cameras are fused into a 360-degree overhead view of the vehicle body, and finally displayed on the screen of the center console, so that the driver can clearly check whether there are obstacles around the vehicle and understand the relative position and distance of the obstacles, helping the driver to easily park the vehicle. Not only is it very intuitive, but also there is no blind spot, which can improve the driver's comfortable control of the vehicle parking or passing through complex roads, effectively reducing the occurrence of accidents such as scratching, collision, and sinking.

[0004] At present, the surround view camera lens generally uses a wide-angle lens, which has the problems of large aberration, large field curvature, poor imaging quality, etc., and is difficult to meet the user's needs. SUMMARY

[0005] In view of the above problems, the purpose of the present application is to provide an optical lens with the advantages of excellent imaging quality.

[0006] The present application provides an optical lens, which has a total of seven lenses, and sequentially includes, along the optical axis from the object side to the imaging surface:

[0007] The first lens has a negative focal length, the object side surface is convex, and the image side surface is concave;

[0008] The second lens has a negative focal length, the object side surface is convex, and the image side surface is concave;

[0009] The third lens has a positive focal length, the object side surface is concave, and the image side surface is convex;

[0010] The fourth lens has a negative focal length, the object side surface is concave, and the image side surface is convex;

[0011] The fifth lens has a negative focal length, the object side surface is convex, and the image side surface is concave;

[0012] The sixth lens has a positive focal length, both the object side surface and the image side surface are convex;

[0013] The seventh lens has a negative focal length, the object side surface is concave, and the image side surface is convex;

[0014] The object-side radius of curvature R3 of the second lens and the image-side radius of curvature R4 of the second lens satisfy: 5.0 < (R3 + R4) / (R3 - R4) < 8.0.

[0015] More 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: 7.5 < (R5 + R6) / (R5 - R6).

[0016] Further preferably, the total optical length (TTL) of the optical lens and the effective focal length (f) satisfy: 7.5 <TTL / f<8.5。

[0017] Further preferably, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view satisfy: 3.0 <TTL / IH<3.5。

[0018] Further preferably, the true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD satisfy: 4.0 <IH / EPD<4.5。

[0019] Further preferably, the optical back focal length BFL of the optical lens and the effective focal length f satisfy: 1.0 <BFL / f<1.5。

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.0 <f1 / f<-2.5。

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -11.5 <f2 / f<-6.5。

[0022] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 8.0 <f3 / f<9.0。

[0023] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -55.0 <f4 / f<-50.0。

[0024] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -4.5 <f5 / f<-4.0。

[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 Structure diagram of the optical lens in Embodiment 1 of the present application.

[0028] Figure 2 Field curvature curve of the optical lens in Embodiment 1 of the present application.

[0029] Figure 3 F-Theta distortion curve of the optical lens in Embodiment 1 of the present application.

[0030] Figure 4 Relative illumination curve of the optical lens in Embodiment 1 of the present application.

[0031] Figure 5 MTF curve of the optical lens in Embodiment 1 of the present application.

[0032] Figure 6 Axial aberration curve of the optical lens in Embodiment 1 of the present application.

[0033] Figure 7 Tangential chromatic aberration curve of the optical lens in Embodiment 1 of the present application.

[0034] Figure 8 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0035] Figure 9 Field curvature curve of the optical lens in Embodiment 2 of the present application.

[0036] Figure 10 F-Theta distortion curve of the optical lens in Embodiment 2 of the present application.

[0037] Figure 11 Relative illumination curve of the optical lens in Embodiment 2 of the present application.

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

[0039] Figure 13 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0040] Figure 14 Tangential chromatic aberration curve of the optical lens in Embodiment 2 of the present application.

[0041] The following detailed description will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0042] For a better understanding of the present application, various aspects of the present application will be presented in more detail by referring to the attached drawings. It should be understood that these detailed descriptions are merely descriptive of the embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, like drawing reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0043] It should be noted that the expressions first, second, third and the like in this specification are used only to distinguish one feature from another feature, and do not indicate any limitation of the features. Thus, the first lens discussed below can also be referred to as a second lens or a third lens without departing from the teachings of the present application.

[0044] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for the sake of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0045] In this specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0046] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. Furthermore, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0047] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the terms should be interpreted as having a meaning that is 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.

[0048] It should be noted that the embodiments and features of the present application can be combined with each other in the case of no conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] The optical lens of the embodiment of the present application comprises, in sequence along the optical axis from the object side to the imaging surface, a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens, a seventh lens, a filter and a protective glass.

[0050] In some embodiments, the first lens can have a negative focal power, which is conducive to reducing the inclination angle of the incident light, thereby effectively sharing the large field of view on the object side. The object side of the first lens is convex, and the image side is concave, which is conducive to collecting as much edge field of view light as possible into the rear optical lens, thereby realizing large-angle light collection.

[0051] In some embodiments, the second lens can have a negative focal power, which can share the negative focal power of the front end of the lens, thereby reducing the excessive folding of light caused by the excessive concentration of the focal power of the first lens, and reducing the difficulty of chromatic aberration correction of the optical lens. The image side of the second lens is concave, which is conducive to converging the outgoing light, avoiding excessive size of the lens outer diameter.

[0052] In some embodiments, the third lens can have a positive focal power, which is conducive to improving the light convergence ability of the optical lens. The object side of the third lens is concave, and the image side is convex, which can effectively avoid the excessive folding angle of the edge field of view light in the process of transferring the light from the second lens to the third lens, thereby reducing the difficulty of chromatic aberration correction of the optical lens and improving the imaging quality of the optical lens.

[0053] In some embodiments, the fourth lens can have a negative focal power, and the object side thereof is concave and the image side is convex, which is conducive to reducing the light folding angle and making the light trend smooth and transition, thereby improving the imaging quality of the optical lens.

[0054] In some embodiments, the fifth lens can have a negative focal power, which is conducive to increasing the imaging area of the optical lens and improving the imaging quality of the optical lens. The object side of the fifth lens is convex, and the image side is concave, which can reduce the ghost energy of the light reflected by the object side of the fifth lens, and also reduce the spherical aberration generated by the fifth lens itself, thereby improving the imaging quality of the optical lens.

[0055] In some embodiments, the sixth lens can have a positive focal power, which is conducive to improving the chromatic aberration of the optical lens and improving the imaging quality of the optical lens. The object side and the image side of the sixth lens are both convex, which is conducive to forming a cemented lens with the fifth lens, thereby improving the chromatic aberration of the optical lens and improving the imaging quality of the optical lens.

[0056] In some embodiments, the seventh lens has negative refractive power, which is beneficial to increase the imaging area of the optical lens and improve the imaging quality of the optical lens. The object side surface of the seventh lens is concave, and the image side surface is convex, which is beneficial to compress the angle of the edge field of view incident on the imaging surface, effectively transfer more light beams to the imaging surface, and improve the imaging quality of the optical lens.

[0057] In some embodiments, the object side surface radius of curvature R3 of the second lens and the image side surface radius of curvature R4 of the second lens satisfy: 5.0<(R3+R4) / (R3-R4)<8.0. Satisfying the above range can effectively receive the outgoing light rays from the image side surface of the first lens, and improve the relative luminance of the optical lens.

[0058] In some embodiments, the total track length TTL of the optical lens and the effective focal length f satisfy: 7.5<TTL / f<8.5. Satisfying the above range ensures sufficient space to adjust the lens structure and optimize the imaging effect.

[0059] In some embodiments, the total track length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle satisfy: 3.0<TTL / IH<3.5. Satisfying the above range can effectively balance the demand for image height and miniaturization of the optical lens.

[0060] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value FNO satisfy: 95°<FOV / FNO<105°. Satisfying the above range is beneficial to expand the field of view angle of the optical lens and increase the aperture of the optical lens, which is beneficial to the optical lens to obtain more scene information, meet the demand for large range detection, and the realization of large aperture characteristics is beneficial to improve the problem of rapid decline of relative brightness of the edge field of view, thereby also being beneficial to obtain more scene information.

[0061] In some embodiments, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field of view angle satisfy: 0.9<(IH / 2) / (f x θ)<0.95. Satisfying the above range is beneficial to control the smooth change of the edge distortion of the optical lens, and is convenient for later restoration through software algorithm.

[0062] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD satisfy: 4.0<IH / EPD<4.5. Satisfying the above range can increase the width of the light beam entering the optical lens, so that the brightness of the optical lens at the image surface is improved to avoid dark corners.

[0063] In some embodiments, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field of view angle satisfy: 2.2<IH / f<2.8. Satisfying the above range is beneficial to balance the size of the field of view angle and the size of the F-Theta distortion of the optical lens, and improve the imaging quality of the optical lens.

[0064] In some embodiments, the optical back focal length BFL of the optical lens and the effective focal length f satisfy: 1.0<BFL / f<1.5. Satisfying the above range is beneficial to balance the good imaging quality and the easy-to-assemble optical back focal length length, to ensure the imaging quality of the optical lens while avoiding interference between the lens and other elements, and to reduce the assembly process difficulty of the camera module.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.0<f1 / f<-2.5. Satisfying the above range can make the first lens have appropriate negative focal power, which is beneficial to reduce the inclination angle of the incident light, and is beneficial to collect as much edge field of view light as possible into the rear optical lens, to realize large-angle light collection.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -11.5<f2 / f<-6.5. Satisfying the above range can make the second lens have appropriate negative focal power, which can share the negative focal power of the front end of the lens, thereby reducing the excessive light deflection caused by the excessive concentration of the focal power of the first lens, and reducing the difficulty of chromatic aberration correction of the optical lens.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 8.0<f3 / f<9.0. Satisfying the above range can make the third lens have appropriate positive focal power, which is beneficial to improve the light convergence ability of the optical lens. It is beneficial to correct the astigmatism and field curvature introduced by the front end of the lens, and to 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 f4 of the fourth lens satisfy: -55.0<f4 / f<-50.0. Satisfying the above range can make the fourth lens have appropriate negative focal power, which is beneficial to reduce the light deflection angle and make the light trend smooth transition, and improve the imaging quality of the optical lens.

[0069] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -4.5<f5 / f<-4.0. Satisfying the above range can make the fifth lens have appropriate negative focal power, which is beneficial to reduce the light deflection angle and make the light trend smooth transition, and improve the imaging quality of the optical lens.

[0070] 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 < 1.5. Satisfying the above range, the sixth lens can have appropriate positive refractive power, which is conducive to improving the light converging capability of the optical lens, balancing various aberrations generated by the optical lens, and improving the imaging quality of the optical lens.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -115.0 < f7 / f < -50.0. Satisfying the above range, the seventh lens can have appropriate negative refractive power, which is conducive to suppressing the angle of the edge field of view incident on the imaging surface, effectively transmitting more light beams to the imaging surface, and improving the imaging quality of the optical lens.

[0072] In some embodiments, the object side surface curvature radius R5 of the third lens and the image side surface curvature radius R6 of the third lens satisfy: 7.5 < (R5+R6) / (R5-R6). Satisfying the above range, the light deflection angle can be reduced, and the light trend is more stable.

[0073] In some embodiments, the object side surface curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: 7.5 < R1 / f. The image side surface curvature radius R2 of the first lens and the effective focal length f of the optical lens satisfy: R2 / f < 1.9. Satisfying the above range, the ultra-wide-angle characteristic can be achieved, so that more scene information can be obtained, and the demand for wide-range detection of the optical lens can be met.

[0074] In some embodiments, the object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: 5.5 < R1 / R2 < 6.5. Satisfying the above range, the wide-angle characteristic can be achieved, so that more scene information can be obtained, and the demand for wide-range detection of the optical lens can be met.

[0075] In some embodiments, the object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy: 1.0 < R3 / R4 < 1.8. Satisfying the above range, the coma and field curvature generated by the second lens itself can be balanced, so that the lens imaging quality is improved.

[0076] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the center thicknesses of the first lens to the seventh lens along the optical axis respectively satisfy: 0.3 < ∑CT / TTL < 0.7. Satisfying the above range, the structure design and production process of the optical lens are conducive.

[0077] In some embodiments, the effective focal length f of the optical lens and the central thickness CT3 of the third lens along the optical axis satisfy: 0.2 < CT3 / f < 0.5. By satisfying the above range, the thickness of the third lens can be set to improve the field curvature of the ultra-wide-angle lens, reduce the difficulty of lens aberration optimization, and thus improve the imaging quality of the lens.

[0078] In some embodiments, the fifth lens and the sixth lens can be glued to form a glued 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 improve the imaging quality of the optical lens. In addition, the glued lens 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.

[0079] In some embodiments, the seventh lens can adopt an aspherical lens surface to improve the resolution quality.

[0080] In order to make the system have better optical performance, an aspherical lens is used in the lens, and each aspherical surface of the optical lens satisfies the following equation:

[0081]

[0082] Wherein, z is the distance of the curved surface to the vertex of the curved surface in the direction of the optical axis, 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 quadratic surface coefficient, 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.

[0083] The application will be further described in the following embodiments. In each embodiment, the thickness, curvature radius, and material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments. Any change, replacement, combination, or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement, and should be included in the protection scope of the application.

[0084] Embodiment 1

[0085] Please refer to Figure 1 , which is a structure schematic diagram of the optical lens provided in the embodiment 1 of the application. The optical lens 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, a fourth lens L4, a diaphragm ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0086] The first lens L1 has a negative focal length, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface.

[0087] The second lens L2 has negative focal power, the object side S3 is a convex surface, and the image side S4 is a concave surface;

[0088] The third lens L3 has positive focal power, the object side S5 is a concave surface, and the image side S6 is a convex surface;

[0089] The fourth lens L4 has negative focal power, the object side S7 is a concave surface, and the image side S8 is a convex surface;

[0090] The stop ST;

[0091] The fifth lens L5 has negative focal power, the object side S9 is a convex surface, and the image side S10 is a concave surface;

[0092] The sixth lens L6 has positive focal power, the object side S10 and the image side S11 are both convex surfaces;

[0093] 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;

[0094] The seventh lens L7 has negative focal power, the object side S12 is a concave surface, and the image side S13 is a convex surface;

[0095] The object side S14 and the image side S15 of the filter G1 are both flat surfaces;

[0096] The object side S16 and the image side S17 of the protective glass G2 are both flat surfaces;

[0097] The imaging surface S18 is a flat surface.

[0098] The related parameters of the lenses in the optical lens in Embodiment 1 are shown in Table 1-1.

[0099] Table 1-1

[0100]

[0101] The surface type parameters of the aspherical lens of the optical lens in Embodiment 1 are shown in Table 1-2.

[0102] Table 1-2

[0103]

[0104] In this embodiment, the field curvature curve, the F-Theta distortion curve, the relative luminance curve, the MTF curve, the axial aberration curve, and the off-axis chromatic aberration curve of the optical lens are respectively as shown in Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7As shown.

[0105] 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 -0.06 mm to 0.04 mm, indicating that the optical lens can effectively correct the field curvature.

[0106] Figure 3 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within -8% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0107] Figure 4 The 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 60% at the maximum half-field angle, indicating that the optical lens has good relative illumination.

[0108] 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 0.3 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.

[0109] 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 -5μm to 30μm, indicating that the optical lens can correct axial aberration well.

[0110] Figure 7The vertical axis represents the relative vertical color aberration value (unit: μm) of each wavelength to the central wavelength (0.55 μm), and the longitudinal axis represents the normalized field of view. It can be seen from the figure that the vertical color aberration of the longest wavelength and the shortest wavelength is controlled within -4 μm~6 μm, which indicates that the optical lens can well correct the color aberration of the edge field of view and the secondary spectrum of the whole image surface.

[0111] Embodiment 2

[0112] Please refer to Figure 8 , which is a structural schematic diagram of the optical lens provided in Embodiment 2 of the present application. Compared with Embodiment 1, the main difference of the present embodiment is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0113] The related parameters of each lens in the optical lens in Embodiment 2 are shown in Table 2-1.

[0114] Table 2-1

[0115]

[0116] The surface type parameters of the aspherical lens of the optical lens in Embodiment 2 are shown in Table 2-2.

[0117] Table 2-2

[0118]

[0119] In the present embodiment, the field curvature curve, the F-Theta distortion curve, the relative luminance curve, the MTF curve, the axial aberration curve and the vertical color aberration curve of the optical lens are shown in Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 respectively.

[0120] Figure 9 The field curvature curve of Embodiment 2 is shown, which represents the bending degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the longitudinal axis represents the half field of view (unit: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.06 mm~0.04 mm, which indicates that the optical lens can well correct the field curvature.

[0121] Figure 10F-Theta distortion curve of embodiment 2 is shown, which represents F-Theta distortion of light rays of different wavelengths at different image heights on the imaging plane, the horizontal axis represents F-Theta distortion value (unit: %), and the vertical axis represents half field angle (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within-8%~0, the image compression in the edge angle region is relatively gentle, and the clarity of the expanded image is effectively improved.

[0122] Figure 11 The relative illumination curve of embodiment 2 is shown, which represents the relative illumination value of 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 60% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0123] Figure 12 The MTF (Modulation Transfer Function) curve of embodiment 2 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.3 within the full field of view, and in the range of 0~160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge field of view, and has good imaging quality and good detail resolution ability in low and high frequency conditions.

[0124] Figure 13 The axial aberration curve of embodiment 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 offset of the axial aberration is controlled within-5μm~30μm, indicating that the optical lens can better correct the axial aberration.

[0125] Figure 14 The axial aberration curve of embodiment 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 offset of the axial aberration is controlled within-5μm~30μm, indicating that the optical lens can better correct the axial aberration.

[0126] Please refer to Table 3, the optical properties corresponding to each of the above embodiments, including the effective focal length f, the total optical length TTL, the aperture value FNO, the real image height IH, and the maximum field of view FOV of the optical lens, and the numerical value corresponding to each conditional expression in each embodiment.

[0127] Table 3

[0128]

[0129] In summary of the above embodiments, the optical lens provided by the present application improves the imaging quality of the optical lens, reduces aberration, and improves the imaging quality of the optical lens by reasonable configuration of each lens surface and reasonable matching of optical power.

[0130] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0131] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging plane along the optical axis, the optical lens comprises in sequence: a first lens with negative refractive power, whose object side surface is a convex surface and whose image side surface is a concave surface; a second lens with negative refractive power, whose object side surface is a convex surface and whose image side surface is a concave surface; a third lens with positive refractive power, whose object side surface is a concave surface and whose image side surface is a convex surface; a fourth lens with negative refractive power, whose object side surface is a concave surface and whose image side surface is a convex surface; a fifth lens with negative refractive power, whose object side surface is a convex surface and whose image side surface is a concave surface; a sixth lens with positive refractive power, whose object side surface and image side surface are both convex surfaces; a seventh lens with negative refractive power, whose object side surface is a concave surface and whose image side surface is a convex surface; a curvature radius R3 of the object side surface of the second lens and a curvature radius R4 of the image side surface of the second lens satisfy: 5.0<(R3+R4) / (R3-R4)<8.

0.

2. The optical lens of claim 1, wherein, a curvature radius R5 of the object side surface of the third lens and a curvature radius R6 of the image side surface of the third lens satisfy: 7.5<(R5+R6) / (R5-R6).

3. The optical lens of claim 1, wherein, an optical total track length TTL of the optical lens and an effective focal length f satisfy: 7.5<TTL / f<8.

5.

4. The optical lens of claim 1, wherein, an optical total track length TTL of the optical lens and a real image height IH corresponding to a maximum field of view angle satisfy: 3.0<TTL / IH<3.

5.

5. The optical lens of claim 1, wherein, a real image height IH corresponding to a maximum field of view angle of the optical lens and an entrance pupil diameter EPD satisfy: 4.0<IH / EPD<4.

5.

6. The optical lens of claim 1, wherein, an optical back focal length BFL of the optical lens and an effective focal length f satisfy: 1.0<BFL / f<1.

5.

7. The optical lens of claim 1, wherein, an effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: -4.0<f1 / f<-2.

5.

8. The optical lens of claim 1, wherein, an effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: -11.5<f2 / f<-6.

5.

9. The optical lens of claim 1, wherein, an effective focal length f of the optical lens and a focal length f3 of the third lens satisfy: 8.0<f3 / f<9.

0.

10. The optical lens of claim 1, wherein, an effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: -55.0<f4 / f<-50.0.

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