Optical lens

Abstract

The application provides an optical lens, which comprises six lenses in sequence along an optical axis from an object side to an imaging surface, and the six lenses comprise: a first lens with negative optical power, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with positive optical power, wherein the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; a third lens with positive optical power, wherein the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; a fourth lens with positive optical power, wherein the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; a fifth lens with positive optical power, wherein the object side surface and the image side surface of the fifth lens are both convex surfaces; and a sixth lens with positive optical power, wherein the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a concave surface. The optical lens provided by the application can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and make the lens have one or more advantages such as miniaturization, large aperture, large field of view, high imaging quality and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to an optical lens. BACKGROUND

[0002] Nowadays, laser radar is widely used in detecting three-dimensional coordinates and ranging of objects. The laser radar includes a controller, a light source and a receiving device. The controller controls the light source to emit a light beam. The light beam is diffusely reflected after encountering a target object. The receiving device receives the reflected light beam, and determines relevant information of the target object, such as target distance, direction, height, speed, attitude and even shape, according to the information of the emitted light beam and the reflected light beam. Laser radar is widely used in autonomous vehicles, unmanned aerial vehicles, autonomous robots, satellites and rockets.

[0003] As a key component of laser radar, the optical lens can receive and process the reflected light. However, the imaging quality of the optical lens of the current laser radar is not high, which cannot meet the market demand. SUMMARY

[0004] In view of the above problems, the present application aims to provide an optical lens with excellent imaging quality.

[0005] The technical scheme adopted by the present application is as follows:

[0006] An optical lens includes six lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface, and include:

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

[0008] The second lens has positive focal power, the object side surface is concave, and the image side surface is convex;

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

[0010] The fourth lens has positive focal power, the object side surface is concave, and the image side surface is convex;

[0011] The fifth lens has positive focal power, and both the object side surface and the image side surface are convex;

[0012] The sixth lens has positive focal power, the object side surface is convex, and the image side surface is concave;

[0013] The maximum field angle of the optical lens corresponds to a real image height IH, an effective focal length f and an arc radian of the maximum half field angle θ, and satisfies: 0.9 < (IH / 2) / (f x θ) < 1.1.

[0014] It is further preferred that the maximum field of view FOV of the optical lens and the aperture value Fno satisfy: 95° < FOV / Fno < 110°.

[0015] It is further preferred that the maximum field of view FOV of the optical lens and the aperture value Fno satisfy: 95° < FOV / Fno < 110°.

[0016] It is further preferred that the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: BFL / f > 0.8.

[0017] It is further preferred that the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 6 < f2 / f < 12.

[0018] It is further preferred that the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: f3 / f > 20.

[0019] It is further preferred that the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 3.8 < f6 / f < 5.8.

[0020] It is further preferred that the effective focal length f of the optical lens and the object side surface curvature radius R5 of the third lens satisfy: 1.5 < R5 / f < 4.5.

[0021] It is further preferred that the object side surface curvature radius R5 of the third lens and the image side surface curvature radius R6 of the third lens satisfy: 0.6 < R5 / R6 < 1.3.

[0022] It is further preferred that the combined focal length f12 of the first lens and the second lens and the distance CT23 of the second lens and the third lens on the optical axis satisfy: f12 / CT23 < -70.

[0023] The optical lens provided by the present application adopts six lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages of miniaturization, large aperture, large field of view, high imaging quality, etc. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0025] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0026] Figure 2The field curvature curve of the optical lens in Embodiment 1 of the present application.

[0027] Figure 3 The F-Theta distortion curve of the optical lens in Embodiment 1 of the present application.

[0028] Figure 4 The axial aberration curve of the optical lens in Embodiment 1 of the present application.

[0029] Figure 5 The lateral chromatic aberration curve of the optical lens in Embodiment 1 of the present application.

[0030] Figure 6 The MTF curve of the optical lens in Embodiment 1 of the present application.

[0031] Figure 7 The relative illumination curve of the optical lens in Embodiment 1 of the present application.

[0032] Figure 8 The structure diagram of the optical lens in Embodiment 2 of the present application.

[0033] Figure 9 The field curvature curve of the optical lens in Embodiment 2 of the present application.

[0034] Figure 10 The F-Theta distortion curve of the optical lens in Embodiment 2 of the present application.

[0035] Figure 11 The axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0036] Figure 12 The lateral chromatic aberration curve of the optical lens in Embodiment 2 of the present application.

[0037] Figure 13 The MTF curve of the optical lens in Embodiment 2 of the present application.

[0038] Figure 14 The relative illumination curve of the optical lens in Embodiment 2 of the present application.

[0039] Figure 15 The structure diagram of the optical lens in Embodiment 3 of the present application.

[0040] Figure 16 The field curvature curve of the optical lens in Embodiment 3 of the present application.

[0041] Figure 17 The F-Theta distortion curve of the optical lens in Embodiment 3 of the present application.

[0042] Figure 18 The axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0043] Figure 19 A graph of the lateral chromatic aberration curve of the optical lens in Embodiment 3 of the present application.

[0044] Figure 20 A graph of the MTF curve of the optical lens in Embodiment 3 of the present application.

[0045] Figure 21 A graph of the relative luminance curve of the optical lens in Embodiment 3 of the present application.

[0046] The following detailed description will further describe the present application with reference to 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 below with reference to the accompanying drawings. It is to be noted that these detailed descriptions are only descriptions of 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.

[0048] It is to be noted that, in the present specification, the expressions first, second, third and the like are used only to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0049] 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 the aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0050] In the present 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.

[0051] It should also be understood that the use of the terms "have", "has", "having", "include", "includes" or "including" when used in this specification, specifies the presence of stated features, elements, components, and / or integers, but do not preclude the presence or addition of one or more other features, elements, components, and / or integers. In addition, it should be understood that when terms such as "at least one" are used in the detailed description, the terms are intended to be interpreted as "one or more". Furthermore, use of the term "about" when used in this specification in connection with a numerical value shall mean the value of the specified amount + / - 10% of that value.

[0052] 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 will be further understood that terms, such as those defined in commonly used dictionaries, 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.

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

[0054] The optical lens provided by the embodiments of the present application comprises six lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface as the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens.

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

[0056] In some embodiments, the optical lens can further comprise a diaphragm, which can be located between the second lens and the third lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging. In addition, when the diaphragm is located between the second lens and the third lens, the diaphragm can reasonably distribute the functions of the first lens to the sixth lens, for example, the first lens and the second lens can be used to receive light to a greater extent, and the third lens to the sixth lens can be used for the function of correcting aberration, which is conducive to balancing the structure of the entire optical system. In addition, when the diaphragm is located between the second lens and the third lens, the diaphragm aberration can be corrected.

[0057] In some embodiments, the optical lens can further include a filter, which can be disposed between the sixth lens and the imaging surface. The filter is used to filter out interference light, preventing the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0058] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens, the effective focal length f, and the radian θ of the maximum half field of view angle satisfy: 0.9 < (IH / 2) / (f x θ) < 1.1. Satisfying the above range, the distortion of the optical lens is controlled within a suitable range, which is conducive to increasing the real image height and improving the resolution and imaging quality of the lens.

[0059] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno satisfy: 95° < FOV / Fno < 110°. Satisfying the above range, by controlling the field of view angle and the aperture value within a suitable range, it is conducive to the optical lens to obtain more scene information to meet the demand for large-range detection, and the implementation of the large-aperture feature is conducive to improving the relative luminance of the edge field of view, thereby also conducive to obtaining more scene information.

[0060] 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 of the optical lens satisfy: 2.2 < IH / EPD < 2.9. Satisfying the above range, by controlling the image height and the entrance pupil diameter within a suitable range, it is helpful to increase the width of the light beam entering the optical lens and improve the image plane brightness.

[0061] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: BFL / f > 0.8. More specifically, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.8 < BFL / f < 1.4. Satisfying the above range, the back focus of the optical lens is controlled within a suitable range, which is helpful to balance between the optical back focal length length that is easy to assemble and excellent imaging quality, ensuring the imaging quality of the optical lens while reducing the camera module assembly process difficulty.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 6 < f2 / f < 12. Satisfying the above range, the second lens is controlled to have appropriate positive refractive power, which can converge light, reduce the light deflection angle, and improve the imaging quality.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: f3 / f>20. More specifically, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 20

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 3.8

[0065] In some embodiments, the effective focal length f of the optical lens and the radius of curvature R5 of the object side surface of the third lens satisfy: 1.5

[0066] 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: 0.6

[0067] In some embodiments, the combined focal length f12 of the first lens and the second lens and the distance CT23 of the second lens and the third lens on the optical axis satisfy: f12 / CT23<-70. More specifically, the combined focal length f12 of the first lens and the second lens and the distance CT23 of the second lens and the third lens on the optical axis satisfy: -110

[0068] 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 satisfy: 2.4

[0069] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.5 < f1 / f < -1.5. Satisfying the above range, the first lens is controlled to have appropriate negative refractive power, which can make a large amount of light enter the optical lens from the front end, and increase the field of view.

[0070] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 3.1 < f4 / f < 3.9. Satisfying the above range, the fourth lens is controlled to have appropriate positive refractive power, which can balance the lens aberration and improve the imaging quality.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2.7 < f5 / f < 3.6. Satisfying the above range, the fifth lens is controlled to have appropriate positive refractive power, which can optimize the spherical aberration and improve the imaging quality.

[0072] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f3456 of the third lens, the fourth lens, the fifth lens and the sixth lens satisfy: -2.5 < f12 / f3456 < -1.3. Satisfying the above range, the combined focal length of the front lens group and the rear lens group is controlled to be within a reasonable range, which is conducive to reasonably configuring the refractive power distribution of the optical lens and maintaining the compactness of the optical lens.

[0073] In some embodiments, the effective focal length f of the optical lens and the object side surface curvature radius R7 of the fourth lens satisfy: -5.1 < R7 / f < -2.5. Satisfying the above range, the lens focal length and the object side surface of the fourth lens are controlled to be within a certain reasonable range, which is helpful to further balance the lens aberration and improve the imaging quality.

[0074] In some embodiments, the effective focal length f of the optical lens and the image side surface curvature radius R10 of the fifth lens satisfy: -9.2 < R10 / f < -3.7. Satisfying the above range, the lens focal length and the image side surface of the fifth lens are controlled to be within a certain reasonable range, which can further optimize the spherical aberration and improve the imaging quality.

[0075] 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: -0.05 < (R5-R6) / (R5+R6) < 0.05. Satisfying the above range, the shape of the object side surface and the image side surface of the third lens is controlled, which is helpful to reduce the processing difficulty of the third lens and reduce the production cost.

[0076] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: 3.3<(R3+R4) / (R3-R4)<6.9. Satisfying the above range, the shape of the object side surface and the image side surface of the second lens is controlled, which is conducive to reducing the difficulty of aberration correction of subsequent lenses and improving the imaging quality.

[0077] In some embodiments, the sagittal height Sag6 of the image side surface of the third lens and the half light entrance diameter d6 of the image side surface of the third lens satisfy: 0.1<Sag6 / d6<0.2. Satisfying the above range, the relationship between the sagittal height and the half light entrance diameter of the image side surface of the third lens is controlled, which can control the degree of concave of the image side surface of the third lens and help to control the light path and highlight the details of the central field of view of the optical lens.

[0078] 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 sixth lens along the optical axis respectively satisfy: 0.45<∑CT / TTL<0.65. Satisfying the above range, the total optical length of the optical lens and the sum of the central thicknesses of the lenses are controlled within a reasonable range, which can facilitate structural design and processing and further improve the imaging quality.

[0079] In some embodiments, the half light entrance diameter d1 of the object side surface of the first lens, the real image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.55<d1 / (IH / 2) / tan(FOV / 2)<0.85. Satisfying the above range, the half light entrance diameter of the object side surface of the first lens, the image surface, and the field of view angle are controlled within a reasonable range, which helps to limit the overall shape of the optical lens and make the optical lens have good structural stability.

[0080] In some embodiments, the total optical length TTL of the optical lens and the axial distance SL between the stop and the imaging surface satisfy: 0.7<SL / TTL<0.8. Satisfying the above range, the relationship between the axial distance between the stop and the imaging surface and the total optical length is controlled, which is conducive to reducing the tolerance sensitivity of the optical lens.

[0081] In some embodiments, the optical lens satisfies the following conditional expressions: 2.7mm < f < 3.2mm; 110° < FOV < 140°; 2.2mm < EPD < 2.6mm; 15mm < TTL < 19mm; 1.15 < FNO < 1.35; 5.4mm < IH < 7mm; 6° < CRA < 8°; 2.5mm < BFL < 4.2mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, FNO represents the aperture value of the optical lens, IH represents the real image height corresponding to the maximum field of view angle of the optical lens, CRA represents the chief ray angle of incidence of the optical lens, and BFL represents the back focal length of the optical lens. By satisfying the above ranges, the optical lens has one or more advantages such as miniaturization, large aperture, large field of view angle, etc.

[0082] In some embodiments, the lens material in the optical lens provided by the present application can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present application can adopt a full-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0083] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens can adopt a spherical lens or an aspherical lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens of the present application all adopt a spherical lens.

[0084] The present application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature, and the 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 present application, but the embodiments of the present application are not limited to the following embodiments only, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the present application should be regarded as equivalent replacement modes, and are all included in the protection scope of the present application.

[0085] Embodiment 1

[0086] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the present application. The optical lens 100 includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a diaphragm ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter G1.

[0087] The first lens L1 has negative focal power, the object side S1 is a convex surface, and the image side S2 is a concave surface;

[0088] The second lens L2 has positive focal power, the object side S3 is a concave surface, and the image side S4 is a convex surface;

[0089] The third lens L3 has positive focal power, the object side S5 is a convex surface, and the image side S6 is a concave surface;

[0090] The fourth lens L4 has positive focal power, the object side S7 is a concave surface, and the image side S8 is a convex surface;

[0091] The fifth lens L5 has positive focal power, the object side S9 and the image side S10 are both convex surfaces;

[0092] The sixth lens L6 has positive focal power, the object side S11 is a convex surface, and the image side S12 is a concave surface;

[0093] The object side S13 and the image side S14 of the filter G1 are both flat surfaces;

[0094] The imaging surface S15 is a flat surface.

[0095] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all glass spherical lenses.

[0096] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1.

[0097] Table 1

[0098]

[0099]

[0100] In this embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, the transverse chromatic aberration curve, the MTF curve, and the relative illumination curve of the optical lens 100 are shown in FIGS. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7

[0101] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the curvature 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 vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.04 mm-0.08 mm, which shows that the optical lens can well correct the field curvature.​

[0102] Figure 3 F-Theta distortion curve of embodiment 1 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-2%~0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0103] Figure 4 The axial aberration curve of embodiment 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: mm), 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-0.02mm~0.08mm, which shows that the optical lens can better correct the axial aberration.

[0104] Figure 5 The curve of the axial color difference of embodiment 1 is shown, which represents the color difference of each wavelength at different image heights on the imaging plane relative to the central wavelength (0.94μm), the horizontal axis represents the axial color difference value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the axial color difference of the longest wavelength and the shortest wavelength is controlled within±5μm, which shows that the optical lens can very well correct the color difference of the edge field and the secondary spectrum of the entire image plane.

[0105] Figure 6 The MTF (Modulation Transfer Function) curve of embodiment 1 is shown, which represents the lens imaging modulation of 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 0.18 in the full field of view, and in the range of 0~90lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in low and high frequency conditions.

[0106] Figure 7 The relative illumination curve of embodiment 1 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 80% at the maximum half field angle, which shows that the optical lens has good relative illumination.

[0107] Embodiment 2

[0108] Please refer to Figure 8The figure shown is a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0109] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2.

[0110] Table 2

[0111]

[0112] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, MTF curve, and relative illumination curve of the optical lens 200 are respectively as follows: Figure 9 , Figure 10 , Figure 11 , Figure 12 , Figure 13 , Figure 14 As shown.

[0113] from Figure 9 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.04mm to 0.08mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0114] from Figure 10 As can be seen, the F-Theta distortion of the optical lens 200 is controlled within -2% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.

[0115] from Figure 11 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.08mm, indicating that the optical lens 200 can correct axial aberration well.

[0116] from Figure 12 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -5μm to 4μm, indicating that the optical lens 200 can correct the chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane very well.

[0117] from Figure 13 As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0118] from Figure 14It can be seen from the above table 2 that the relative illumination value of the optical lens 200 is still greater than 80% at the maximum half field angle, which indicates that the optical lens 200 has a good relative illumination.

[0119] Embodiment 3

[0120] Please refer to Figure 15 , which is a structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present application. Compared with Embodiment 1, the main difference is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0121] The related parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3.

[0122] Table 3

[0123]

[0124]

[0125] In this embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, the transverse chromatic aberration curve, the MTF curve and the relative illumination curve of the optical lens 300 are shown in Figure 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 、 Figure 21 respectively.

[0126] It can be seen from Figure 16 that the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.04mm~0.08mm, which indicates that the optical lens 300 can well correct the field curvature.

[0127] It can be seen from Figure 17 that the F-Theta distortion of the optical lens 300 is controlled within-10%~0, and the image compression in the edge angle region is relatively flat, which effectively improves the definition of the expanded image.

[0128] It can be seen from Figure 18 that the shift amount of the axial aberration is controlled within-0.02mm~0.07mm, which indicates that the optical lens 300 can well correct the axial aberration.

[0129] It can be seen from Figure 19 that the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±4μm, which indicates that the optical lens 300 can very well correct the chromatic aberration of the edge field of view and the second spectrum of the entire image surface.

[0130] It can be seen from Figure 20As can be seen from the MTF curves, the MTF values of the optical lens 300 of the embodiment are all above 0.2 in the full field of view, and the MTF curves are uniformly and smoothly decreased from the center to the edge of the field of view in the range of 0-900 lp / mm, and the optical lens 300 has good imaging quality and good detail resolution in the case of low frequency and high frequency.

[0131] From Figure 21 As can be seen from the relative illumination curves, the relative illumination values of the optical lens 300 are still greater than 70% at the maximum half field of view angle, which indicates that the optical lens 300 has good relative illumination.

[0132] Referring to Table 4, the optical properties of the above embodiments are shown, including the effective focal length f, the total track length TTL, the aperture value Fno, the chief ray angle CRA, the real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV of the optical lens, and the numerical value corresponding to each conditional expression in each embodiment.

[0133] Table 4

[0134]

[0135]

[0136] In summary of the above embodiments, the optical lens provided by the present application adopts six lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the optical lens has one or more advantages of miniaturization, large aperture, large field of view angle, high imaging quality, etc.

[0137] In the description of the present specification, the description of 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.

[0138] 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 ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within 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, six pieces of lenses in total, characterized in that, In order from the object side to the imaging surface 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 positive refractive power, whose object side surface is a concave surface and whose image side surface is a convex surface; a third lens with positive refractive power, whose object side surface is a convex surface and whose image side surface is a concave surface; a fourth lens with positive refractive power, whose object side surface is a concave surface and whose image side surface is a convex surface; a fifth lens with positive refractive power, whose object side surface and image side surface are both convex surfaces; a sixth lens with positive refractive power, whose object side surface is a convex surface and whose image side surface is a concave surface; wherein the real image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f and the radian θ of the maximum half field angle satisfy: 0.9 < (IH / 2) / (f×θ) < 1.

1.

2. The optical lens of claim 1, wherein, The maximum field angle FOV of the optical lens and the aperture value Fno satisfy: 95° < FOV / Fno < 110°.

3. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 2.2 < IH / EPD < 2.

9.

4. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: BFL / f > 0.

8.

5. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 6 < f2 / f < 12.

6. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: f3 / f > 20.

7. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 3.8 < f6 / f < 5.

8.

8. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the object side surface curvature radius R5 of the third lens satisfy: 1.5 < R5 / f < 4.

5.

9. The optical lens of claim 1, wherein, The object side surface curvature radius R5 of the third lens and the image side surface curvature radius R6 of the third lens satisfy: 0.6 < R5 / R6 < 1.

3.

10. The optical lens of claim 1, wherein, The combined focal length f12 of the first lens and the second lens and the distance CT23 of the second lens and the third lens on the optical axis satisfy: f12 / CT23 < -70.

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